Safety Featured in ASA Scientific Presentations
Two New ASA Patient Safety Videotapes Now Available
Pain Guidelines Published
Closed Claims Project Subject of ASA Panel
Editorial: President Reviews 1992, State of APSF
ASA Exhibits Show Safety Suggestions
ASA Slightly Modifies Standards
APSF Awards 4 Safety Research Grants for 1993
Comments Sought on New FDA Preanesthesia Checklist
Text of 1992 Proposed FDA Anesthesia Checklist
E.S. Siker, M.D., Named APSF Executive Director
Letters to the Editor
Young Investigators Award Extended to CA-4 Year
By Stanley Aukburg, M.D., Ian Ehrenwerth, M.D., William Gild, M.B.,Ch.B., J.D., Susan Polk, M.D., John P. McGee, M.D., and Gerald Zeitlin, M.D.
Patient safety repeated this year as a prominent theme of the scientific sessions of the Annual Meeting of the American Society of Anesthesiologists October 17-21 in New Orleans. In six sessions, there were 89 individual scientific presentations.
Two papers were presented which raised concern about the potential for epidural catheter contamination. The first was offered by Drs. P. Langevin, P. Guley, and N. Gravenstein of the University of Florida at Gainesville. Their in-vitro study indicated that bacteria are not likely to migrate more than eight inches along a catheter from the point at which it is externally contaminated and that immersion of the catheter in betadine for three minutes followed by air drying for three minutes effectively sterilized it. They conclude that if the lower connector of an epidural catheter becomes inadvertently disconnected subjecting the catheter to potential contamination, it is probably safe to reconnect it if at least eight inches of the catheter is cut away using sterile technique and the cut end is treated with betadine as above. A related paper from Dr. M. Dailey, et al. of the Medical University of South Carolina presented a compilation of reports of epidural abscesses after epidural blockade. Their data, which included all reported cases of epidural abscess in the last 15 years, revealed 13 infections, all occurring in patients who had the catheters placed for pain control outside of the OR environment. These two reports emphasize the necessity for employing aseptic technique when placing epidural catheters.
Dr. 0. Hendon, et al. of the University of California at San Diego presented data from confidential questionnaires indicating that anesthesiologists
have a higher incidence of sleep disturbances than the general population. Cumulative sleep debt and poor quality sleep have the potential to hamper performance of anesthesia personnel. In a companion paper, they reported that 75% of 85 subjects drank alcohol on a regular basis, that 10% of the subjects had at least once been hung over while administrating anesthesia, and 40% administered anesthesia within 12 hours of alcohol consumption. Sixty-three percent of the anesthesia providers admitted to having ever used marijuana. Four of 38 respondents admitted to using other controlled substances including cocaine, benzodiazepines, opiates, hallucinogens, amphetamines and N20. One subject reported that he had lost consciousness during administration of anesthesia due to an overdose of midazolam. Sixteen percent of the subjects said that they had seriously contemplated suicide yet no one admitted actually attempting it. Taken together, the studies appear to indicate a significant incidence of substance abuse and mental disturbance among anesthesia personnel. (See Letter to the Editor, pg. 51.)
Drs. M. Hartmannsgraber and N. Gravenstein of the University of Florida reported a study indicating that a commercially available air eliminator supplied with a blood warmer/rapid infuser was not effective in removing large volumes of air and did not eliminate the need for rigorous air elimination from the system prior to clinical use.
Dr. R. Keenan and associates from the Medical College of Virginia reported on their study of bradycardia during anesthesia in infants. Their enquiry focused on the incidence and influencing factors on this relatively common and serious problem. They found that the likelihood of bradycardia (defined as baseline) was increased in sicker infants undergoing emergency procedures of longer duration. Independent of these variables, bradycardia was 2.2 times more likely when infants were attended by non-pediatric anesthetists than by their pediatric counterparts.
Two papers addressed the use of nitrous oxide for patients undergoing bone marrow harvest. Dr. D. Fausel and associates from the Cleveland Clinic Foundation examined the influence of nitrous oxide (during anesthesia for the donor) on time to bone marrow engraftment in recipients. They found that exposure to this agent had no significant influence on this time. Dr. G. Lederhaas and coworkers at Stanford University examined bone marrow viability as assessed by colony forming unit-granulocyte macrophage assay (CFU-GM) and found that human bone marrow exposed to nitrous oxide experienced no significant difference in viability. Both papers concluded that use of nitrous oxide in patients undergoing bone marrow donation is not contraindicated.
Dr. J. Gross and colleagues from the University of Connecticut examined the effects of midazolam and diazepam on SaO2 during conscious sedation. Using a randomized, double-blind study technique on 86 patients, they found that equi-sedating doses of these two drugs significantly reduced SaO2 for up to 80 minutes, and that there were no significant differences between the drugs at any time during
the study period. Both drugs caused SaO2 to fall below 85% in some patients breathing room air. They concluded that midazolam (compared to diazepam) did not appear to increase the risk of hypoxemia during conscious sedation, but that both held the potential to cause significant desaturation. They emphasized the need for careful monitoring of patients sedated with either drug.
Hct Doesn't Help
Dr. M. Bodner and associates at Washington University in St. Louis examined the relationship between cardiovascular morbidity and perioperative hematocrit (Hct) in patients undergoing radical prostatectomy. They found that there was no significant difference in the lowest documented Hct in patients who had cardiovascular morbidity and those who did not, thus negating the predictive value of patient hematocrit. With increasing awareness of viral transmission during blood transfusion, this study would support a more cautious approach to transfusion timing.
Two presentations dealt with patient recall during anesthesia. The first, by Dr. M. Clemency and associates of Emory University, examined the incidence of recall of surgery following anesthesia for trauma. They found an overall rate of recall of 5% (less than in previous studies in this patient population), but when data were stratified by .minutes without anesthesia' the results showed (not unsurprisingly) that those patients with more than 15 minutes of no anesthesia had a higher incidence of recall than those with less (33% vs. 2%). Surprisingly, the incidence of recall did not appear to be influenced by the use of amnestics, although numbers examined were quite small. They urged further study of the effectiveness of amnestics in anesthesia for trauma. The second study, by Dr. W. Gild (University of Washington, Seattle) and associates in the Closed Claims Project, examined liability aspects of recall following surgery and unintentional administration of muscle relaxants to awake patients. They found a 2% incidence of recall and awake paralysis in the Closed Claims Data Base (n m 2400). Thirty-three of the claims involved recall of intraoperative events (recall), while 12 resulted from unintentional administration of muscle relaxants to awake patients (awake paralysis). Award amounts for all these claims were significantly less than for other claims in the data base ($10K vs. $95K), standard of care was judged (by peers) to have been met less frequently in the awareness claims than others (24% vs. 44%), and no consistent pattern of causation could be discerned in the recall subgroup of claims. The awake paralysis claims involved simple lapses of vigilance and carelessness. The study underscores present lack of understanding of the etiology of the awareness and recall of events during general anesthetics.
Dr. B. McGrath and coworkers at George Washington University studied the incidence of pulmonary embolization from pneumatic tourniquet use during orthopedic surgery using transesophageal echocardiography. Evidence of 'solid' emboli was seen in 5 of the 22 patients studied (all following deflation of the tourniquet). Patients with embolization suffered no significant changes in BP or 02 saturation. They found that embolization following deflation of lower leg tourniquet is a relatively common event (23%) and was seen independent of whether marrow cavities were entered. They thus concluded that the solid emboli seen were venous thrombi and called for further study to determine the nature and significance of emboli and the potential effectiveness of anti-thrombus prophylaxis.
Predicting Difficult Intubations
Dr. J.S. McDonald and colleagues from Ohio State University studied 1,501 patients who underwent laryngoscopy and intubation. In each of these patients, visualization during laryngoscopy was graded on a scale of 1-4 (I being good visualization and 4 being very poor). They then recorded eight factors on each patient to see if the difficult intubations could be predicted from these physical signs. The factors included: visualization of tonsillar pillars, mentum-suprahyoid distance, mentum-sternal notch distance, oral opening distance, range of neck motion, body habitus, receding mandible, and buck teeth. These characteristics were scored on a form during the preoperative visit. Seventy-nine patients (5.3%) were felt to have a larynx that was difficult to visualize (Grade 3) and 23 patients (1.5%) were felt to have a larynx that was very difficult to visualize (Grade 4). Several different analyses performed to determine if there was a relationship between any single factor or group of factors and the visualization score failed to reveal any consistent relationship. The authors also noted that 12 cases (1%) had oxygen saturations of less than 90%. They concluded that anatomic scoring methods used to prospectively predict difficult intubations are largely unreliable as screening tools.
Fire in the Operating Rooms
Dr. R. Westerlund from New York University Medical Center reported on the problems encountered when a fire broke out during a neurosurgical procedure when a hand-held laser was accidentally discharged while aimed at the operating room drapes. The fire produced dense acrid smoke that forced everyone out of the room in less than two minutes. The patient was fixed to the table with pins and could not be moved, and visibility in the room was near zero.
In reviewing the experience, the author developed some important general guidelines. First, do not assume that a fire cannot occur in your operating room. Instead plan ahead and think about what would have to be done if a fire did take place. It is important to know the types and locations of fire extinguishers in the operating room, as different fire extinguishers have different uses. For instance, halon can be used around electronic equipment, but it consumes oxygen in the room. Carbon dioxide leaves granular particles. The locations of alarm boxes, gas shut off valves, and emergency equipment should be known by all personnel. Auxiliary lighting, such as flashlights, and fire blankets should be available.
Some general safety precautions should also be followed. There should be stringent rules for control of sources of ignition (i.e., lasers, electrocautery and hot fiberoptic cords). Keep ignition sources away from flammable solutions and combustible material. Use of laser-resistant drapes should be encouraged during these cases. Plan how to remove burning drapes, covers and clothing. Pouring water on an impervious drape will not extinguish the fire as it will continue to burn on the underside of the drape. In these cases, it is necessary to remove the drapes and then attempt to extinguish the fire. It should not be assumed that the fire is entirely out until the entire area is thoroughly inspected.
Personnel should be prepared to react in the presence of heavy acrid smoke. It should not be assumed that one can function normally in the presence of a smoke filled room, as the heavy smoke may make it impossible to see or breathe. During a fire, personnel may be forced to leave the O.R. without being able to help the patient. Do not assume that the ventilation system will clear the smoke. Most ventilation systems have smoke detectors which shut off the exhaust to that room in the event of a fire. Care for the anesthetized patient in a hazardous environment is something that requires a great deal of advanced preparation.
Lower Extremity Nerve Injury in the Lithotomy Position
Drs. M. Warner and J. Martin of the Mayo Clinic reviewed more than 1,000,000 entries in the Mayo Clinic database of surgical cases performed from 1957-1992 to try to determine the incidence of lower extremity nerve injury in the lithotomy position. The records were scanned for 56 surgical procedures historically done in the lithotomy position, resulting in 198,000 cases which were further examined using ICD*2*CM diagnosis codes for 26 different nerve injuries and four compartment syndromes. To be classified as a persistent nerve injury, a motor deficit had to be present for greater than three months' duration, and the compartment syndrome was defined as the presence of the diagnosis plus fasciotomy.
The authors found 922 patients; 59 were determined by three independent anesthesiologists to have complications related to their procedure in the lithotomy position. Of these 59 patients, 54 (1:3,675) had persistent nerve injury while five patients (1:39,692) had compartment syndromes. Although preliminary data do not identify mechanisms of injury, many potential factors are possible. The authors are currently involved in study of these 59 patients to determined the relative contribution of various factors to nerve injury in the lithotomy position. The authors further extrapolated their data to say that approximately 500 cases of persistent nerve injury and 50 cases of compartment syndrome could be expected in the U.S. each year from surgery in this position.
Can Simulation Accelerate the Learning of Basic Anesthesia Skills?
Dr. M. Good and colleagues from the University of Florida studied 26 residents just beginning their anesthesia training to determine whether basic anesthesia skills taught in a simulator would accelerate learning over the conventional lecture format. The residents were divided into two groups and every day for two weeks the residents either attended a lecture or trained in the simulator. There were 10 learning objectives which included checking and operating the anesthesia machine and ventilator, inducing general anesthesia, managing emergence and reversal of muscle relaxants, and diagnosing and treating hypoxemia. The residents were evaluated on the basis of a 'multiple choice test and by evaluations of their critical performance by the faculty.
The pre-test and post-test did not show any significant difference between the two groups. However, at Week 3 the change in the clinical evaluation scores in the simulator group were significantly better than those in the didactic group, but by Week 13 the two groups were equal in their clinical evaluation scores. The authors concluded that teaching basic anesthesia skills to new residents by use of an anesthesia simulator can accelerate initial learning when compared with the traditional lecture format.
Airway Management Issues
Several papers addressed airway management. Dr. R. From and associates from the University of Iowa presented their evaluation of 'Sim I,' an interactive computerized learning program for airway management developed for use in ACLS courses, in teaching medical students during their third year anesthesia clerkship. Students received either the traditional preclinical instruction on airway management from department faculty or utilized Sim 1 without faculty interaction, and then their airway management skills were evaluated when they got to the operating room. There was no difference between the two groups in the degree of difficulty managing airways by faculty evaluations or by their own evaluations, nor was the students' level of satisfaction different. The investigators conclude that the simulation program is no more effective than faculty instruction in introduction to airway management, and are not utilizing this technology in their clerkship program.
Two papers discussed the laryngeal mask airway (LMA). Dr. J. Pennant and colleagues from the University of Texas, Southwestern, evaluated this device as a method of initial airway management in patients presenting with a possible cervical spine injury in a rigid collar. Placing a rigid collar on normal volunteer patients prior to inducing anesthesia, they compared the time to airway securement after induction of anesthesia and paralysis utilizing the LMA or conventional laryngoscopy and intubation. They found the LMA to allow faster and easier positive pressure ventilation. They believe this device should be used when endotracheal intubation is difficult or impossible in patients with possible cervical spine instability and there is an immediate need for oxygenation and/or ventilation, even though it does not reliably protect the airway from aspiration.
Dr. M. Maroof and associates from King Fahad National Guard Hospital in Riyadh, Saudi Arabia, reported their modification to the LMA which allows it to be used as a route for fiberoptic intubation (FOI) with adult size endotracheal tubes. By removing the pliable grates at the opening and slitting the device lengthwise along its entire length including the cuff, they were able to insert the endotracheal tube through it and then remove the LMA from around the tube. Without the lengthwise slit, only a size 6 or smaller tube can be inserted over a fiberoptic scope and the device has to remain taped in place until the endotracheal tube is removed. This group tested the modified MLA as an aid to fiberoptic intubation (FOI) by comparing time to successful intubation with and without the device by experienced and inexperienced operators. Using the device hastened intubation for both experienced and inexperienced and markedly increased the success rate for those inexperienced in the technique of FOI. From these two reports, it appears that the LMA can play a significant role both in enhancing patient safety and teaching skills of fiberoptic intubation.
Dr. K. Davis, Wilford Hall U.S.A.F. Hospital in San Antonio, reported results of a survey to determine the prevalence of skills in fiberoptic intubation (FOI) among anesthesiologists in the U.S. Teaching hospitals have more fiberoptic intubating bronchoscopes, use them more often, and feel they are more necessary than non-teaching hospitals. Academic faculty and senior residents report a higher success rate and feel more capable with FOI than do anesthesiologists in non-teaching hospitals. Dr. Davis concludes that if an anesthesiologist is not able to acquire confidence and skill in this technique during residency, it is unlikely that he or she will be able to pick it up later.
Drs. S. Marsch and H. Keller report from the University of Basel, Switzerland, that in that country FOI occurs three times more often in teaching than non-teaching hospitals. Because electively performing oral FOI after induction of anesthesia and paralysis is an excellent means of acquiring this skill, they determined if there was a difference in patient hemodynamic profile or postoperative morbidity using FOI as compared to conventional laryngoscopy and intubation. Four third-year residents without previous FOI experience were instructed in the technique with a video introduction and extensive practice on a mannequin. They then performed FOI on 10 patients and 10 conventional intubations, at which they were considered expert, in random sequence. FOI took significantly longer than conventional intubation for these novices (average 76 vs. 20 seconds), but hemodynamic data were recorded on each patient and there was no difference in the profiles using either intubation technique. There was also no difference in the incidence of postoperative sore throat, dysphagia, or hoarseness with the two techniques. The authors conclude that it does not compromise patient safety to learn this technique by elective FOI after induction of anesthesia.
The Anterior Orifice
Confirming endotracheal intubation was addressed in two papers. Drs. W. Gentry and C. Shanks from Northwestern University described the Ford Maneuver using the Miller laryngoscope blade. In this maneuver after the endotracheal tube is positioned (hopefully) in the trachea and while the laryngoscope is still in place, a simple dorsal push of the tube in the pharynx while exerting ventral pressure on the laryngoscope brings the larynx into view so that the position of the tube passing between the vocal cords can be directly viewed. They evaluated this maneuver's efficacy in improving the Cormack and Lehane grade for larynx visualization after intubation in 94 patients and found that it improved the grade in 71% of patients. The Ford Maneuver had previously been evaluated only using the MacIntosh blade.
Dr. R. Salem and associates from Illinois Masonic Medical Center in Chicago described another simple means of testing for endotracheal tube placement using a self inflating bulb from an asepto syringe. After tube placement, the bulb is deflated and attached to the endotracheal tube. If the tube is in the esophagus, the bulb will not reinflate. If the tube is in the trachea, it will. This group tested the efficacy of the bulb in identifying esophageal intubation in the presence of a nasogastric tube, and found that it still led to no false positive conclusions. Dr. Salem points out that there still might be false negatives, when the tube is in the trachea but the bulb does not inflate. In cases where the tube is linked, there is severe distal airway obstruction, or the diaphragm is moving and creating negative airway pressure.
The pathogenesis of carbon monoxide production in anesthesia circuits was investigated by Dr. R. Moon and colleagues from Duke University. Postulating that fluroform in association with sodalime might be responsible for the formation of CO, this group passed fluroform and the three inhalational anesthetics through sodalime canisters at slow flows for 4-8 hours, then the canisters were allowed to sit overnight. They were flushed with air the following morning and the effluent gas analyzed for CO. The level of CO did increase with the passage of inhaled agents and fluoroform through sodalime, but not to the high levels occasionally reported in the literature. The authors conclude that passage of fluorinated hydrocarbons through sodalime does produce some CO in the circuit, especially after the canister sits for a period of time, but that some other mechanism must also be involved. They recommend using high fresh gas flows (>5 LPM) during anesthetic administration, frequent changes of C02 absorbent canisters, and flushing the circuit before using it after it has sat idle for a time.
Dr. A. Wong and his group from the Hospital for Sick Children in Toronto investigated the cause of airway fires during tonsillectomy, studying the contributions of an oxygen enriched atmosphere in the pharynx, N20, and the presence of saline, epinephrine and bismuth on the tonsillar packs. Measuring oxygen concentrations in the pharynx of children undergoing tonsillectomy, they found that >21% oxygen occurred when uncuffed tubes were used with controlled ventilation. Reproducing the environments they found in the pharynx in bell jars, they tried to ignite cotton packs soaked in saline, in epinephrine and in epinephrine and bismuth with diathermy. The results showed that the presence of an enhanced oxygen atmosphere increases combustibility of the packs no matter what they are soaked in. The dryer the packs become, the more likely they are to ignite in an oxygen enhanced environment. Finally, addition of bismuth to the packs significantly increases combustibility. Efforts to prevent fires should include limiting leaks around the endotracheal tube by using spontaneous ventilation and keeping the packs wet.
Post op Airway
Evaluating, retaining, and treating the airway after extubation is critical, especially if the post operative airway cannot be manipulated. Drs. R. Cooper and S. Levytam from Toronto Hospital have developed a 65 cm catheter that can be placed through the endotracheal tube and is well-tolerated when left in situ after extubation. This tube can be used for gas aspiration and capnography, insufflation of 02, or jet ventilation. A spiral pattern of side-holes at the distal end of the catheter allows jet ventilation without catheter whip. The authors reported on 51 patients in whom it had been used. Capnography and oxygenation were the two most common applications. Jet ventilation was feasible, but barotrauma is still possible, especially if the upper airway is obstructed.
Safety of procedures continues to be a major focus of investigations both in the USA and abroad. The threat of a major vein perforation even days after the placement of a CVP or multi-lumen catheter into a central vein limits the usefulness of ft route of venous access, especially on the general nursing floor. Drs. R. Blackshear and N. Gravenstein from the University of Florida have examined five different catheter types regarding their potential to perforate a membrane in an in vitro testing situation. Catheters having rounded tips rather than beveled tips were much less likely to perforate. Some of the catheters which perforated the in vitro membrane easily had also been associated with in vivo perforations in the authors' institution.
The safe use of a drug depends on careful attention to known safety policies, one of which is the use of a test dose anytime a potentially toxic dose of local anesthetic is injected. Dr. Y. Auroy et al. from Clamart, France queried French anesthetists working in surgical centers performing upper limb surgery under axillary block. They found a higher than expected neurologic and cardiovascular toxicity rate. More importantly, these experienced anesthetists were careful to aspirate and inject the anesthetic slowly but rarely used a test dose, as was the routine practice in performing epidurals. In another presentation, the safety of epidural anesthesia by residents was analyzed by Dr. J. Naulty et al. from George Washington University. Prospectively following 10 residents and analyzing Ql forms and anesthesia records showed that unintended dural punctures fell from 5% to 1% over three years and the need to replace an epidural catheter because of inadequate anesthesia fell from 7% to 2%, but the incidence of IV placement of the epidural catheter did not change with time, remaining steady at 4% over the training period. This further indicates the importance of a test dose to seek evidence of intravascular placement of either needle or catheter.
Perioperative heat loss continues to be a topic of concern. Dr. M. Barhorst et al. from the Mayo Clinic examined the temperature fall in patients transported from the OR to the PACU (4.6 minutes average time). Patients having continuous epidural anesthesia were colder at the end of surgery (34.80 C by tympanic membrane probe) than were the patients given general anesthesia (35.6o C). The epidural group temperature fell 0.3' C while the general anesthesia group temperature fell 0.1 Co. Such differences in core temperature seem small, but Dr. C. Sheffield et al. from the University of California, San Francisco suggest that mild hypothermia of 30 C may significantly alter resistance to infection. They anesthetized guinea pigs for 6 hrs each, maintaining normal core temperature in 12 and 30 C low in 12 others. Three doses of S. Aureus were inoculated intradermally after two hours. Four days later, at the sites of the greatest inoculum, the bacteria from the normothermic animals had decreased by 50% while the bacterial count from the sites from the hypothermic animals had increased slightly.
Effectiveness of monitoring practices was also studied. Knowing error patterns of commonly used and relied-upon monitors is a needed feature of safety research. Dr. S. Barker et al. from the University of California, Irvine, examined the responses of five different pulse oximeters when placed deliberately half-on the finger or ear lobe but still recording pulse accurately. The saturation readings were significantly in error but not necessarily predictably so. The pulse oximeter should be in a position that the anesthetist can frequently check it or reposition it if artifactual readings occur. Dr. G. D'Honneur et al. from Creteil, France, examined the precision and bias of two commonly used neuromuscular stimulation techniques (train-of-four and double-burst) in evaluating neuromuscular recovery after reversal of muscle relaxants. recording pulse accurately. The saturation readings were significantly in error but not necessarily predictably so. The pulse oximeter should be in a position that the anesthetist can frequently check it or reposition it if artifactual readings occur. Dr. G. D'Honneur et al. from Creteil, France, examined the precision and bias of two commonly used neuromuscular stimulation techniques (train-of-four and double-burst) in evaluating neuromuscular recovery after reversal of muscle relaxants. 200 patients who had had abdominal surgery were examined immediately after arriving in the recovery room. Double-burst simulation was more precise at recovery levels of TOF 40-70%, which is the important section of the neuromuscular recovery curve in the recovery room. At either end of the recovery spectrum, however, the two monitoring methods were equivalent.
An example of reluctance to follow directions was reported by Dr. M. Roizen et al. in a multicenter report regarding the phase IV post-marking study of propofol. The use of the drug was to start with induction doses only and proceed to induction and maintenance by intermittent injection and finally to TIVA by infusion. The study revealed that the drug was usually used on fairly healthy patients (healthier than the usual surgical population). However, occasional practitioners used it very quickly on older, sicker patients with resulting hypotension and bradycardia, and a number of practitioners began the third step of the phased use before finishing the first or second. The analysis indicated that generally the bulk of anesthesiologists are conservative in the early use of a new drug.
Conscious sedation by either midazolam or diazepam was shown to be equally depressing to SpO2 during conscious sedation (Dr. J. Gross, University of Connecticut), and direct feed-back from a capnograph was shown to improve the efficiency of CPR as measured by higher C02 elimination (Y. Lambert et al., Creteil, France)
Postoperative complications were addressed in two papers. Dr. B. Grundy and associates from the University of Florida utilized telemetered pulse oximetry on the surgical ward to determine if frequency and severity of postoperative hypoxemia could be predicted by any patient or surgical factors. Not surprisingly, obesity (>120% ideal body weight) correlated most strongly with preoperative episodes of SaO2 <90%, but only weakly predicted the severity of postoperative episodes. The greatest predictor of postoperative desaturation episodes was major abdominal surgery, followed distantly by inguinal herniorrhaphy, neurosurgery and superficial procedures in that order. There was no correlation with ASA physical status, age or smoking history. Desaturation episodes were more likely in patients who had received general as contrasted with regional anesthesia. Episodes of desaturation were not confined to the first few nights after surgery and tended to be more severe the later they occurred. Supplemental oxygen therapy did not prevent the episodes. Dr. Grundy and her group continue to utilize this technology and linear analysis to perfect a system to predict who should receive intervention to prevent episodes of postoperative hypoxemia, which they speculate may account for at least part of the cognitive dysfunction reported in some postoperative patients.
Dr. S. Kaseno and colleagues from Hokkaido University In Sapporo, Japan, retrospectively compared a battery of liver function tests in patients who received sevoflurane or isoflurane anesthesia during a 12-month period beginning in September, 1990. They excluded all patients who had preoperative alterations in hepatic or renal function, who received a combined regional and general anesthetic, who received blood products perioperatively, or who had cardiovascular, thoracic or abdominal surgery. There were about 100 patients who received each anesthetic and did not differ in any characteristics. Patients receiving isoflurane showed minimal effects on every liver function test. Patients receiving sevoflurane exhibited significantly higher values for AST, ALT, gammaGTP and LAP than did those receiving isoflurane from 7 to 28 days postoperatively. These elevations correlated with the duration of exposure to the agent. LAP and ALT values were outside the normal range at 14 days for the group receiving sevoflurane, but there was no evidence of clinical liver dysfunction. Bilirubin levels did not change in either group. The impact of this and similar studies on the use of Sevoflurane in this country remains to be seen.
Open Packages Safe
In the arena of cost containment, we were told by a group from the University of South Carolina led by senior medical student M.W. Moore that we can use endotracheal tubes up to at least five days after we open the package and test the cuff, if we don't take the tubes out of their packages and get them dirty. These investigators cultured tubes from opened packages stored in carts of their least and most busy operating rooms at 24, 48 and 120 hours by swabbing them on a blood-agar plate and then immersing them in thioglycolate broth. Neither culture method showed any growth for any tube. The investigators speculate that they can save their department at least $21,000 per year by not discarding all tubes in opened packages at the end of a day, so long as they are careful to keep them clean.
There were several posters summarizing studies about the safety of the anesthesiologist. Dr. A. Tait of the University of Michigan mailed a questionnaire to 70 anesthesiologists at four hospitals asking about their compliance with CDC guidelines for the prevention of HBV and HIV transmission to these practitioners. Forty-seven percent reported having suffered 1 to 2 needlesticks during the previous year. Sixty-three percent admitted to frequently recapping needles; only 6% said they never did so. The figures for those who wore gloves are also remarkable e.g. only 56% wore them even when contact with the patient's blood was a possibility. Nevertheless 50% reported that they had altered their habits since the AIDS scare. The author reminds us it is estimated that 40% of all occupational HIV transmission could have been avoided by proper disposal of needles and by following CDC guidelines.
Dr. A. Rosenberg and colleagues from New York University mailed a questionnaire to a random 10% sample of ASA members and got answers from 1,367 anesthesiologists. They also noted considerable improvement in self protective habits. There was a decrease in reuse of syringes containing drugs such as vasopressors which can be available for several consecutive patients. Residents were better than attendings at wearing gloves when starting IV or arterial lines. During the period of the study, 8.5% of the residents and 3.7% of the attendings sustained needle-sticks while taking care of patients known to be HIV positive.
Drs. W. Merritt and A. Zuckerberg at Johns Hopkins Hospital studied contamination of the anesthetic record. At first blush one would imagine that this refers to such heinous activity as 'smoothing' of notations of vital signs on the anesthetic record. Their study must be taken literally; for on their poster they displayed an anesthetic record with splashes of dried blood. They found that 51 % of the records of anesthetics for CABC and abdominal aneurysm operations were contaminated. Even 15% of those for laparoscopic cholecystectomy were also affected. There war,-' some correlation to the frequency of lab specimens 'I drawn from the patients and number of units of blood administered. They could not always find a mechanism but suggest that increased vigilance, frequent glove changes and hand washing, innovative blood sampling techniques and the use of automated record keeping might diminish this potential hazard to the anesthesiologist.
Dr. M. Williams et al. from the University of Colorado conducted a pilot study to see if physician addicts had any difficulty returning to abstinence after they had had operations which required them to receive sedatives or narcotics. They got their information from the directors of five state recovery programs and received 51 completed replies. Approximately half were ex-alcoholics and the rest were former drug addicts. The mean preoperative period of abstinence was four years. Close to 30% of the former drug addicts developed cravings for their former drug of choice and experienced emotional lability and the need for supportive care whereas only 7.4% of alcoholics relapsed. The authors conclude that even years after recovery addicts may be at risk for relapse if exposed to sedatives or narcotics given for surgical indications.
Lastly, Dr. J. Zacny and associates wondered if propofol had the potential to become a drug of abuse. They studied the subjective effects of subanesthetic dose infusions in 10 volunteers and performed a double blind randomized cross-over study using the vehicle for propofol, Intralipid, as a control. Five of the subjects liked the real thing whereas most of the group on receiving the vehicle were neutral about its effects. The authors conclude from this preliminary study that propofol may have some potential for abuse.
In all, the diverse and extensive spectrum of safety-related presentations at this year's meeting illustrates yet again that patient safety issues have become a very significant component of anesthesia practice.
Dr. Aukburg, University of Pennsylvania, is a member of the Newsletter Editorial Board. Dr. Ehrenwerth, Yale University, is a member of the Board of Directors of the APSF and a member of the Newsletter Editorial Board. Dr. Gild, University of Washington, chaired one of the ASA scientific sessions, as did Dr. Polk, who is from the University of Chicago; Dr. McGee, Northwestern University is from Evanston (IL) Hospital, and Dr. Zeitlin of the Brigham and Women's Hospital and Harvard in Boston is a Newsletter Associate Editor.
Back to Table of Contents
by Ellison C. Pierce, Jr., M.D.
Infection Control in the Practice of Anesthesia
Infection Control in the Practice of Anesthesia, Videotape Number IS in the series cosponsored by the ASA, considers the prevention of infection in patients undergoing anesthesia, strategies for reducing occupational transmission of infection to practitioners, and the necessity for anesthetists to incorporate universal precautions in infection control. It addresses the procedural considerations for anesthesia concerning nosocomial infection, blood borne pathogens, airborne pathogens, contact pathogens and the awareness of HIV infection. David Cheney, M.D., an anesthesiologist, describes the danger to the anesthesia provider in telling his own experience with an accidental needlestick that led to his becoming HIV Positive.
The program consultants include: William P. Arnold, 111, M.D., Chairman, ASA Committee on Occupational Health of Operating Room Personnel; Arnold J. Berry, M.D., Chairman, ASA Infection Control Policy Task Force; Samuel C. Hughes, M.D., Mark P. Fritz, M.D., Members, ASA Infection Control Policy Task Force; Leon Helton, CRNA, Chairman, AANA Infection Control Task Force; Lynn Van Wormer, CRNA, Brent W. Sommers, CRNA, Members, AANA Infection Control Task Force; Darlene G. Homa, CRNA, Member AANA
The videotape was made possible by an educational grant from Burroughs Wellcome Company and will be available for distribution by them in late Fall. Arnold I. Berry, M.D., was producer and Mark P. Fritz, M.D., and Samuel C. Hughes, M.D., associate producers. Filming took place at Emory University Hospital, Atlanta, GA. GWF Associates, Holmdel, New Jersey, collaborated on scripting, technical development, and filming.
Central Venous Catheter Complications
Central Venous Catheter Complications, Videotape Number 17 comprising a three-part series, was developed to inform clinicians about the many possible complications associated with Central Venous Catheters (CVCs).
The first parts are directed toward individuals who place CVCs and have a need to review the anatomy, pathology and radiology. Later, the tape discusses CVC-related infection and peripherally implanted central lines, as well as home-care aspects of CVC placement and maintenance. The tape was funded and prepared under the direction of the Food and Drug Administration (FDA), several specialty societies and catheter manufacturers. Special recognition should go to the Central Venous Catheter Working Group for their efforts in the planning, preparation and completion of the project. Walter L. Scott, Ph.D., was the Project Director for the FDA and Anesthesiologist David M. Paulus, M.D., University of Florida College of Medicine, Gainesville, the chief Technical Consultant. The APSF acted as the financial holding organization. Segments of the three-part series were taped on location at: New England Deaconess Hospital, Boston, MA; Franklin Square Hospital Center, Baltimore, MD; University of Florida, Shands Hospital, Gainesville, FL; National Institutes of Health, Bethesda, MD; Uniformed Services University of the Health Sciences, Bethesda, MD; Food and Drug Administration, Rockville, MD.
There will be several modes of distribution, including 7,000 copies to -all hospital administrators in the United States. #or American anesthesia practitioners, Burroughs Wellcome Company will begin distribution to 'anesthesia departments in January 1993 in the usual manner. In addition, copies are available to other parties from the National Audiovisual Center for approximately $90.00 a set.
Dr. Pierce, APSF President, is Executive Producer of the
ASA Patient Safety Videotape Series.
Back to Table of Contents
A document entitled 'Critical knowledge and technical competence required of physicians involved in interventional pain management" has been developed by a task force organized by the Dannemiller Memorial Educational Foundation, an organizer of anesthesiology continuing medical education (CME) programs since its inception in 1984.
These guidelines arose from a need perceived by the Dannemiller group and specifically its President, Alon P. Winnie, M.D. of Chicago, due to the absence of any widely accepted standards of care concerning interventional pain management and, especially, implantable pain control devices.
The Dannemiller task force comprised Drs. Winnie, Marshall D. Bedder of Portland, OR, Roger Cicala of Memphis, Elliott J. Krames of San Francisco, Carl Noback of Las Vegas, Gabor Racz of Lubbock, TX, and Steven D. Waldman of Leawood, KS.
Contained in the guidelines document are sections on: scientific basis, patient selection, patient management, implant techniques, practice considerations, and minimum requirements for physicians (such as a prerequisite of at least 16 hours of directly related CME, four of which should involve supervised hands-on surgical experience implanting devices).
A copy of the document can be obtained from the Dannemiller
Foundation; 12500 Network Blvd., Suite 101; San Antonio, TX 78249-3302;
Back to Table of Contents
by Robert A. Caplan, M.D.
The impact of the ASA Closed Claims Project was examined at the ASA Annual Meeting on October 20 in a panel session of the Committee on Professional Liability with the Director of the ASA Closed Claims Project.
Panel participants included Jeffrey B. Cooper, Ph.D. (Director of Anesthesia Technology at Massachusetts General Hospital), Ellison C. Pierce, Jr., M.D. (President of the Anesthesia Patient Safety Foundation), Mr. Mark Wood (Director of Risk Management Services at St. Paul Fire and Marine Insurance Company), and Robert A. Caplan, M.D. (Chairman of the ASA Committee on Patient Safety and Risk Management and Co-Director of the ASA Closed Claims Project). Dr. Fred Cheney, the other Co-Director of the ASA Closed Claims Project, reviewed the history and present status of the Closed Claims Project. The feasibility of closed claims analysis was first demonstrated by Dr. Richard Ward in the mid-1980s. Since that time, the Closed Claims Project has grown vigorously.
At present, the project database contains nearly 3,000 claims, collected from the closed files of approximately 30 U.S. insurance carriers. The primary work force of the project is a dedicated team of practicing anesthesiologists who make a voluntary donation of time and expertise in order to review and analyze closed claims. Dr. Cooper provided a critical appraisal of the project methods, emphasizing the merits of sentinel event analysis and its successful application in this area of research. He also reviewed the limitations imposed by the retrospective nature of Closed Claims data, and the potential for bias and distortion by original participants and later reviewers. Dr. Pierce described the positive impact of the Closed Claim. Project on patient safety, highlighting the pivotal role that claims data have played in the formulation of monitoring standards. Mr. Wood used the claims experience of the St. Paul Company to illustrate the linkage between improved intraoperative monitoring and the reduction in hypoxic injuries. Dr. Caplan presented a brief survey of the scientific study of peer review, another area of focus for the Closed Claims Project. Preliminary research indicates that anesthesiologists show significant agreement on basic issues of peer review, but the strength of agreement is modest and physician judgments are strongly biased by outcome. Explicit tools for case review may improve the validity and reliability of peer review. Dr. Cheney concluded the panel session with a glimpse into the future. He predicted that claims for inadequate ventilation, esophageal intubation, and injuries arising from difficult intubation would all show a considerable decline, largely as the result of pulse oximetry, end-tidal capnography, and improved strategies for difficult airway management. He also predicted that peripheral nerve injuries would persist, unless research efforts yield a better understanding of the basic anesthetic injuries.
Dr. Caplan, Mason Clinic, Seattle, WA, chairman the ASA
Committee on Patient Safety and risk Management, is on the Executive Committee
of the APSF.
Back to Table of Contents
The year 1992 was another good one for the Foundation. An important continuing endeavor was funding for research grants in anesthesia safety, with some $175,000 given to investigators at three institutions. The awards were for examination of safety and risk factors associated with postoperative regional analgesia in pediatric patients; study of the effects of long work hours on the ability of anesthesia and surgical providers to monitor multiple sources of information, to learn and to retain information; and application of the technique of probabilistic risk assessment to develop a quantitative risk analysis model for anesthesia and to assess the effects of organizational factors in the risk of accidents.
The Newsletter continues to be the major organ worldwide for dissemination of issues of importance in anesthesia patient safety. With more than 50,000 copies distributed quarterly, it has been cited as the largest-circulation anesthesia publication in the world. In the last four issues, among many items, it reviewed patient safety activities at the ASA meeting, summarized significant articles from the literature, examined specific problems in patient safety, discussed the role that European 'work stations' may have in U.S. anesthesia equipment development, reported on one of the simulator systems that had been partially funded by the Foundation, analyzed whether anesthesiologists and nurse anesthetists have a problem with equipment competency, and described the recent International Standards for Safe Practice, endorsed by the World Federation of Societies of Anesthesiologists.
The APSF continued its strong financial support for development of anesthesia simulators, primarily at Stanford and the University of Florida. In addition to examining the operating room environment, interest will also be directed toward that of the post-anesthetic care unit. In an effort to reduce costs associated with administration, the Foundation has opened an Executive Office in Pittsburgh to be run by the new APSF Executive Director, E. S. Siker, M.D. This undertaking will consolidate nearly all of the Foundation's activities in one center.
The APSF also provided partial funding for the June meeting of the International Committee on Prevention of Anesthesia Morbidity and Mortality as well as for a 1993 meeting on Human Performance in Anesthesia, co-sponsored by APSF and the Society for Technology in Anesthesia. The Foundation has begun an examination of the possibility of developing a nationwide confidential reporting system for collecting safety-related anesthesia events and established a CA-3 investigator award. A major event during the year was the convening of a Board of Directors Retreat in New Orleans preceding the ASA annual meeting. Some 45 members of the APSF Board and Committees attended the all day symposium.
Lastly, all of us on the APSF Executive Committee and Board appreciate the significant interest in the Foundation seen on the part of many anesthesiologists worldwide. As noted last year, other specialty societies and the American Medical Association continue to laud the anesthesia community for its leadership role in patient safety activities.
E.C. Pierce, Jr., M.D. President APSF
Back to Table of Contents
by John H. Eichhorn, M.D.
Safety-related technology and ideas certainly were featured in the technical and scientific exhibits at the American Society of Anesthesiologists Annual Meeting in New Orleans in October, but there were comparatively few genuinely new ideas. Packaging and presentation of existing technology continues to vary in a multiplicity of permutations and combinations.
In the technical exhibits, patient temperature seemed to surpass oximetry as the most common focus. There were at least 12 major displays centering on the issue of unintended patient hypothermia in the operating room. Many varieties of the already existing mechanisms to add and/or preserve heat in an anesthetized patient (from above, below, or via the gases and fluids) were presented. In response to questioning on the reason for the emphasis on this topic, representatives from various companies with these displays replied that anesthesia practitioners seemed very concerned with their patients who accidentally become cold during surgery.
Various nontraditional monitors were highly touted. There was an esophageal probe that allows ECG recording from directly behind the heart (and another that can be used for cardiac pacing). The cerebral oximeter with an infrared sensor applied to the forehead that is claimed to read regional brain tissue oxygen saturation through the skull bone was displayed again. Advertised as a new technology, a noninvasive cardiac output monitor was shown. It involves two electrodes on the left lateral chest wall and also two at the root of the neck. A low amplitude current is generated and the electrical conductivity of the blood causes changes in intrathoracic incidence that can be detected by the monitor which then does 'time-frequency signal processing' to make projected calculations about the mechanical function of the heart. Among the many parameters displayed on the monitor are CO, stroke volume, ejection fraction, end-diastolic volume, and SVR.
A new smart technology for vessel finding was displayed. An ultrasound device that detected differences, for example, between the internal jugular vein and the carotid artery can be attached to a needle and apparently help guide needles and catheters into the central venous circulation.
Real-time blood gas measurement technologies were more numerous this year. Four that involve intra-arterial sensors and two that make measurements outside the body were displayed. AU these manufacturers stated with no hesitation that they have finally solved the fibrin-deposition problems that have prevented this type of technology from succeeding in the past.
Automated anesthesia record keeping devices and OR information management systems were prominent with three of each offering new upgrades of previously available technology.
In a simple, but important, area, there were several devices shown that are specifically intended to shield and protect anesthetized patients' ulnar nerves from potential compression damage and resulting neuropathy.
New versions of labels for syringes that are intended to help avoid wrong-medication errors were prominently displayed.
A pneumatic device to allow 'pumping up" for left uterine Wt to avoid aorto-caval compression was offered as a new easy way to implement this important safety maneuver.
While not specifically offered as new safety devices, laryngeal mask airways arrived in full force in the US at this meeting. How these impact practice and any safety implications, positive or negative, remains to be seen as they are put into clinical practice and studied.
In the scientific exhibits, there was a demonstration of a proposed simple way to detect esophageal intubation. A compressed large suction bulb is attached to the connector of a newly placed endotracheal tube. If the deflated bulb immediately reinflates, the tube is in the trachea. If not, it is either in the esophagus or obstructed. The presenter stated that this had been used in more than 1,500 anesthetics and it had correctly diagnosed one unrecognized esophageal intubation.
Bulb for Trachea
Potentially a harbinger of the future, another scientific exhibit featured a so-called 'heads-up" display of monitoring information on a screen attached to the surgical drapes at the level of the patient's head. This computer-based projection system allows the monitoring displays to be seen by the anesthetist in the same field of vision as the patient. Such technology may eventually lead to helmet or even eye-glass like devices (similar to those used by fighter pilots) the anesthetist will wear and then have all the monitoring displays always directly in view.
Dr. Eichhorn of the University of Mississippi is Editor of the APSF Newsletter.
Back to Table of Contents
Small but important modifications to two of the formal sets of ASA standards of practice were made by the House of Delegates at the October ASA Annual Meeting.
The Standards for Basic Intraoperative Monitoring were strengthened by the addition of the word 'strongly' to the encouragement of the use of continuous capnography. Item 2 of Standard 11, Ventilation, now reads: "When an endotracheal tube is inserted, its correct positioning in the trachea must be verified by clinical assessment and by identification of carbon dioxide in the expired gas. End-tidal C02 analysis, in use from the time of endotracheal tube placement, is strongly encouraged."
Likewise, the Standards for Postanesthesia Care were supplemented by a new reference to the monitoring of temperature in the immediate postoperative period. The relevant section now reads: "...particular attention should be given to monitoring oxygenation, ventilation, circulation and temperature."
Both changes were recommended by the ASA Committee on
Standards of Care and were adopted by the House without opposition. In
response to the directive from the 1991 House of Delegates, the Committee
did evaluate the suggestion that continuous capnography be made a formal
standard. The Committee felt that to do so would require a number of caveats
and exceptions, particularly regarding pediatric patients, and that this,
coupled with the features already in the existing standard as quoted above,
argued in favor of not adopting the suggestion.
Back to Table of Contents
by Jeffrey B. Cooper, Ph.D.
The APSF Committee on Scientific Evaluation has once again awarded research grants for patient safety-related studies. Four of 15 grant applications were approved for funding of a total of $155,658. These studies represent different aspects of patient safety: study of a factor affecting human performance, validation of a new measurement for studying human performance, mechanisms of a specific event and examination of a new monitoring concept.
Sleepiness and Fatigue in Anesthesiologists in Training
Dr. Steven Howard will lead a unique collaboration between researchers at the Stanford University Department of Anesthesiology and Stanford Sleep Disorders Center to evaluate acute and chronic fatigue in anesthesiology residents.
A variety of experimental methods will be used to (1) quantify the level of sleepiness during .rested' and sleep-deprived states; (2) examine whether or not brief mental lapses (microsleeps) are occurring in residents while on duty; (3) examine sleep, work and recreational habits of anesthesia residents; (4) evaluate a computer-based instrument that measures performance on medically relevant tasks. The latter instrument is modified from the .synthetic work environment' program (SYNWORK) used for examining performance in the US Army.
This study is expected to produce new information about the physiological sleepiness of anesthesia residents, determine for the first time if microsleeps occur and validate a new test of performance. The investigators believe that their techniques and experimental design will avoid flaws in previous studies that hampered objective interpretation of the results.
A Search for Mechanisms of Intraoperative Carbon Monoxide Poisoning
Dr. Richard Moon and colleagues at the Duke University Medical Center will expand their efforts to identify the cause(s) of suspected CO poisoning that has been identified intraoperatively in some cases. Interaction with carbon dioxide absorbent in breathing systems is the primary suspect mechanism. To test as many as six hypotheses, a battery of experiments will be performed using several analytical techniques employing various radiolabelled species. Depending upon the results, two prevention strategies may be examined.
Identifying a Cerebral Ischemic Threshold
A measure of the adequacy of brain oxygen levels is much sought after, but elusive. Transcranial near-infrared spectrometry has been examined as a possible technique. This study, to be undertaken by Dr. Warren Levy at the University of Pennsylvania, has the primary objective of determining the saturation of hemoglobin in the cerebral vasculature that is associated with electroencephalographic evidence of cerebral ischemia. Continuous phase-modulated near-infrared spectrophotometric measurement of changes in hemoglobin saturation and EEG recordings will be performed in patients undergoing implantation of an internal cardioverting defibrillator, a procedure that frequently produces EEG evidence of cerebral ischemia. It is expected that definition of the 'ischemic threshold" could make measurement of cerebral oxygenation possible in situations where alternative monitoring is not successful or practical.
Creating a Measure of Intraoperative Vigilance
Despite the great interest in the concept of vigilance in anesthesia, the few studies of the subject have lacked an objective measure of intraoperative monitoring performance. Dr. Robert Loeb of the University of California Davis Medical Center will lead a study to validate a measure of intraoperative vigilance during the conduct of a routine case. The artificial talk (an extra display mounted on a non invasive blood pressure monitor) was tested in a pilot study (Loeb RG:A measure of intraoperative attention to monitor displays, Anesth Analg, 1993, in press) and its validity will now be examined versus a real task in which the loss of real patient data (a blanked non invasive blood pressure display) must be recognized. The question to be answered is if performance in the simulated vigilance task differs from performance of the real vigilance task. If the simulated task proves valid, Dr. Loeb plans to use it in other studies of factors affecting intraoperative vigilance.
Those considering applying for a grant to begin in January 1994 should contact the APSF Executive Office for instructions for submission. The maximum award will continue to be $50,000.
Dr. Cooper of the Massachusetts General Hospital, Boston,
is the Chairman of the APSF Committee on Scientific Evaluation and a member
of the APSF Executive Committee.
Back to Table of Contents
by Michael L. Good, MD
Revisions to the official, government-sponsored anesthesia equipment checkout recommendations have been proposed and comments from all members of the anesthesia practice community are sought.
In 1987, the United States Food and Drug Administration (FDA) published Anesthesia Apparatus Checkout Recommendations, a checkout procedure by which anesthesiologists and anesthetists can determine whether an anesthesia gas machine is functioning properly and is ready for patient use. Studies of the checkout protocol have revealed that it is neither well understood nor used correctly by a majority of anesthesia practitioners. When challenged to check anesthesia machines intentionally configured with a variety of malfunctioning components, clinicians detected only 28.5% of the faults. (1) In March, 1991, the FDA reviewed the development of the checkout procedure and studies of its effectiveness at a meeting convened by the American Society of Anesthesiologists' (ASA) Committee on Equipment and Facilities. Invited participants included representatives of the ASA, the ASA Committee on Equipment and Facilities, the Anesthesia Patient Safety Foundation (APSF), the American Association of Nurse Anesthetists (AANA), anesthesia machine manufacturers, and anesthesia equipment experts.
The result of that meeting and other subsequent work has led to a 1992 draft revision of the Anesthesia Apparatus Checkout Recommendations. Availability of this document was announced in the October 6, 1992, Federal Register. The FDA has requested that written comments on the draft document be sent by February 16, 1993 to the Dockets Management Branch (HFA-305), Food and Drug Administration, Room 1-23,12420 Parklawn Drive, Rockville, MD 20857. Comments should be identified with the docket number 86B-0058. The Federal Register article announcing availability of revised document merely describes the modifications that transformed the original 1987 Checkout Recommendations into the currently proposed 1992 draft. The Federal Register article does not include the entire document, which makes it impossible to provide meaningful comments. Thus, the complete draft of the 1992 Anesthesia Apparatus Checkout Recommendations is included in this issue of the APSF Newsletter so that anesthesia practitioners can review it. As recommended in a recent APSF Committee on Technology Position Paper, narrative comments describing the rationale for each specific step and for the revision process in general are included.
Many clinicians believe that existing protocols for anesthesia machine checkouts are too long and too complex. Those who revised the recommendations agreed that the average clinician should be able to check an anesthesia machine in 5 minutes or less. This is not possible with the 1987 Checkout Recommendations or with check procedures published by anesthesia machine manufacturers in the manuals for their anesthesia machines.
Contemporary anesthesia gas delivery machines are durable and dependable. They fail infrequently. They are armed with alarms and safety devices, which, coupled with the array of monitoring instruments used in contemporary anesthesia practice, make failure of most components in the anesthesia machine easily detectable before the safety of the anesthetized patient is jeopardized.
Safe Fail Safe?
For example, many checkout protocols include daily testing of the oxygen pressure failure safety mechanism (fail-safe), a durable device that arrests the flow of other gases when the oxygen supply pressure (pipeline or cylinder) decreases below a preset threshold, which prevents continued flow of a hypoxic gas mixture. Does the isolated failure of the fail-safe mechanism put the patient at immediate risk? I do not think so. Failure of the fail-safe mechanism does not affect the normal function of the anesthesia machine as long as the oxygen supply pressure is adequate. Even if the fail-safe mechanism malfunctions AND the oxygen supply pressure is simultaneous lost, the anesthesia provider is warned by several if not all of the following: (1) low oxygen-supply pressure alarm in anesthesia machine, (2) low oxygen-supply pressure alarm in mechanical ventilator, (3) failure of the mechanical ventilator to cycle properly, (4) report of low oxygen concentration in the breathing circuit by the oxygen analyzer (and an alarm if it is set), and (5) report of decreased oxyhemoglobin saturation by the pulse oximeter. Even in a 'worst case" scenario, the anesthesiologist or anesthetist is warned of the developing hypoxic gas mixture, as first the inspired oxygen concentration and then the oxyhemoglobin saturation begin to decrease. This combination (a hypoxic gas mixture and oxyhemoglobin desaturation) indicates that the patient should be disconnected from the anesthesia machine.
In contrast to the seemingly complex fail-safe mechanism, is the seemingly innocuous and simple scavenging system. Yet certain failures of the scavenging system can cause pulmonary barotrauma in just a few breaths! For example, anesthesia personnel have used adhesive tape to incorrectly mate a standard 22-mm breathing circuit hose to the 15-mm scavenging port. If the adhesive tape slips into the hose and obstructs its lumen, a closed circuit is created when mechanical ventilation is instituted. Gas flowing into the breathing system cannot escape, and airway pressures (both inspiratory and expiratory) quickly rise and may exceed 40 cm H20. (This scenario is demonstrated in the ASA/APSF Patient Safety Video 412.)
The 1992 FDA Anesthesia Apparatus Checkout Recommendations have retained or added checks of machine components that fail more frequently than other components (for example, breathing system), and those components that directly and quickly injure the patient when they fail (for example, scavenging system). Components that fail infrequently and that do not put the patient in immediate danger when they do fail are not included in the 1992 Checkout Recommendations but should be checked as part of routine periodic maintenance. In the paragraphs that follow, the specific rationale for each checkout step is discussed.
The introductory paragraph clearly states that the checkout procedure is valid only for anesthesia machines with an ascending ('upright') bellows " of mechanical ventilator and a specific array of monitoring instruments. This configuration forms a web of safety systems that warn the clinician and protect the patient from injury in the event of an isolated component failure.
Clinicians using anesthesia machines that do not conform to this configuration or to current manufacturing and monitoring guidelines must critically analyze the specific failures that might go unrecognized and adapt the checkout procedure as indicated. For example, the 1992 Checkout Recommendations specify that a capnograph should be in use. The 1987 Checkout Recommendations stipulated that clinicians verify that the unidirectional valves are-competent by inhaling and exhaling into isolated limbs of the breathing system. While this is a sensitive test for detecting valve malfunction, many clinicians prefer not to share the breathing system with their patients. Incompetent unidirectional valves are readily detected with a capnograph, an instrument that reports minimum ('inspired') and maximum ('expired' or 'endtidal') concentrations of carbon dioxide and also traces a capnogram, a plot of the airway carbon dioxide concentration as a function of time. Characteristic changes in the shape of the capnogram accompany both incompetent inspiratory and expiratory valves. An incompetent inspiratory valve, however, may not be detected with a capnometer, an instrument that only reports the minimum and maximum concentrations of carbon dioxide during each respiratory cycle.
Steps Removed from the Checkout Recommendations:
Nitrous Oxide and Air Cylinder Gas Supply
Nitrous oxide and air are not life-sustaining gases. While the undetected loss of nitrous oxide may result in 'light' anesthesia and the potential for awareness and recall, once detected, intravenous or other inhaled anesthetic agents can be used to re-establish the appropriate anesthetic depth. Thus, while it may be reassuring to have reserve cylinders of nitrous oxide and air attached to the anesthesia machine, daily checks of their pressure is not thought to enhance safety.
Low Oxygen-Supply Pressure Alum
Contemporary anesthesia machines alarm when the oxygen supply pressure (from pipeline or cylinder) falls below a preset threshold, usually 25 to 30 psig. This alarm sounds each time the anesthesia machine is turned on and off, which pressurizes and depressurizes the alarm mechanism. The 1992 Checkout Recommendations do not include daily checks of this alarm mechanism. Isolated failure of the low oxygen-supply pressure alarm will not injure a patient. Failure of the alarm coupled with loss of oxygen supply pressure should similarly not injure the patient because the oxygen-pressure failure safety mechanism (fail-safe) will arrest the flow of other gases to prevent the patient from inspiring a hypoxic gas mixture. Mechanical ventilators that are powered by oxygen pressure should independently alarm when oxygen supply pressure is lost. Should this alarm in the ventilator also fail, instruments that monitor ventilation of the patient's lungs, specifically the capnograph and spirometer, will immediately warn the clinician because loss of oxygen supply pressure to a mechanical ventilator results in apnea.
Oxygen Pressure-Failure Safety (fail-safe) Mechanism
This device arrests the flow of all gases except oxygen whenever the oxygen supply pressure falls below a preset threshold, typically 30 psig. This prevents the hypoxic gas mixture that would result from the continued flow of, for example, nitrous oxide without oxygen. As with the low oxygen supply pressure alarm, daily testing of the oxygen pressure-failure safety mechanism is not included in the 1992 Checkout Recommendations because its failure does not directly injure the patient, and multiple simultaneous failures are required before the patient is at risk of injury. Even if the oxygen pressure-failure safety mechanism failed along with the simultaneous loss of oxygen supply pressure during anesthesia with nitrous oxide, the low oxygen-supply pressure alarm will indicate loss of oxygen supply pressure. If this alarm failed, as noted in the previous section, the oxygen analyzer and the pulse oximeter will warn the clinician of the hypoxic gas mixture, regardless of its cause.
Steps Retained in or Added to the 1992 Checkout Recommendations:
1. Verify Backup Ventilation Equipment is Available & Functioning
Though rare, certain malfunctions (for example, contaminated oxygen supply, loss of oxygen supply pressure, total obstruction of the breathing system) render the anesthesia machine inoperable. When this happens, a patient must be quickly disconnected from the anesthesia machine and the patient's lungs ventilated by using backup ventilation equipment. Therefore, the 1992 Checkout Recommendations begin with a check of the backup ventilation equipment. Example systems include self-inflating resuscitation bags, or Mapleson-type circuits with separate oxygen cylinder.
2. Check Oxygen Cylinder Supply
The length of time an anesthesia machine can operate on the reserve oxygen cylinder depends on the volume of compressed oxygen in the cylinder and on the rate of use. The volume of oxygen in the reserve cylinder is directly proportional to its pressure, a W oxygen cylinder having 625 liters and a pressure of approximately 2200 psi. The 1992 Checkout Recommendations suggest that at least one reserve oxygen cylinder be at least half full, in other words, have a pressure of at least 1000 psi, which will enable the anesthesia machine to function for 10 minutes to over an hour, depending on rate of use. Because many anesthesia ventilators are powered totally or in part by oxygen, a low flow of oxygen and either spontaneous ventilation or manual ("bag') ventilation will prolong the time the anesthesia machine can operate with a reserve oxygen cylinder.
3. Check Central Pipeline Supplies
Normal operating pressure for pipeline gases is 45 to 55 psi. A lower pressure suggests that a pipeline hose is not properly connected, that the hose is kinked, that the hose or connector is defective, or that the pipeline system itself has a problem. A higher than normal pressure also suggests that the primary problem is the pipeline system, not the anesthesia machine.
4. Check Initial Status of Low Pressure System
This check is a preparatory step in setting certain controls (that is, flow control valves, vaporizer concentration knob) and sensors (that is, sensor for oxygen analyzer) for subsequent steps in the checkout procedure. The vaporizers are checked and, if necessary, filled at this point as well.
5. Perform Leak Check of Machine Low Pressure System
The low pressure system of the anesthesia machine comprises all components between the flow control valves and the common gas outlet and includes the flow meter tubes, vaporizers, connecting manifolds, and, if present, a common gas outlet check valve. The concentration of volatile anesthetic in the fresh gas mixture may be significantly decreased with small leaks, for example 100 ml/min, in the low pressure system of the anesthesia machine, which may result in consciousness and recall. In certain situations, leaks in the low pressure system may also lead to the patient's inspiring a hypoxic gas mixture, even though a nonhypoxic fresh gas flow ratio has been set.
A variety of check procedures have been proposed for detecting leaks in the low pressure system of the anesthesia machine. A positive pressure leak check (occluding the Y-piece of the breathing circuit, pressurizing it to 20 cm H20, and observing the canister pressure gauge for loss of pressure) will not detect a leak in an anesthesia machine with a common outlet check valve, because positive pressure in the breathing system cannot be transmitted back into the low pressure system. The negative pressure leak check (attach suction bulb to common gas outlet, squeeze to develop negative pressure, and observe to see if bulb remains collapsed) detects leaks in the low pressure system on all makes and models of anesthesia machines and is sensitive enough to detect the small leaks (100 ml/min) that can disrupt the proper function of the low pressure system. When done correctly, both positive and negative pressure leak checks require the use of a bulb attachment to the anesthesia machine. Accordingly, so that a single, highly sensitive check procedure could be recommended for all anesthesia machines, the 1992 Checkout Recommendations suggest using the negative pressure leak check for the low
6. Turn On Machine Master Switch
This enables subsequent checks to be performed.
7. Test Flowmeters
This step verifies that gas is flowing into the anesthesia machine; that the flow control valves and flow meters are functioning; and that the 'hypoxic guard' mechanism either prevents the clinician from setting a hypoxic oxygen-nitrous oxide fresh gas flow ratio or alarms when such a flow ratio is set.
8. Calibrate 02 Monitor
A contaminated oxygen supply (for example, oxygen-nitrous oxide pipeline cross, non-oxygen gas in oxygen pipeline or cylinder) can only be diagnosed by a functioning and calibrated oxygen analyzer. Other malfunctions within the anesthesia machine, as well as a very low rate of fresh gas flow, may also lead to hypoxic gas. Therefore, the oxygen analyzer should be calibrated at 21% and checked at high oxygen concentrations daily. (Do not recalibrate the analyzer at a high oxygen concentration because greater accuracy is needed at low concentrations.)
9. Check Initial Status of Breathing System This is a preparatory step in which the clinician assembles and visually checks the breathing system, carbon dioxide absorbent, and any other breathing circuit accessories (for example, PEEP valve, humidifier system) required for the next case. It is important to add breathing circuit accessories before completing the checkout procedure. If the accessory has a fault (for example, a leak in the humidifier circuit), it will not be detected if attached to the anesthesia machine after the machine checkout is complete.
10. Perform Leak Check of the Breathing System
This is the traditional leak check of the breathing system in which the clinician occludes the Y-piece, pressurizes the breathing system with an oxygen flush, and observes the canister pressure to ensure that the breathing system holds pressure (that is, is leak free).
11. Check Adjustable Pressure-Limiting Valve and Scavenging System
Following the leak check of the breathing system, most clinicians depressurize the circuit by removing their finger from the Y-piece. The 1992 Checkout Recommendations, however, suggest that, instead, the Y-piece should be kept occluded; the adjustable pressure-limiting (APL), or 'pop-off', valve be opened; and the pressure be allowed to dissipate through this valve into the scavenging system. Though rare, should the APL fad to open properly, gas cannot escape from the breathing system, which creates a closed system and, thus, potential for excessive inspiratory and expiratory airway pressures and resultant barotrauma.
The latter half of this step is checking the scavenging system. Like the malfunctioning APL valve, an obstruction in the scavenging system can also create a closed system and increase airway pressures, which may result in cardiovascular compromise and barotrauma. Similarly, malfunction of the negative pressure relief mechanism in an active (that is, vacuum) scavenging system can transmit negative pressure back to the patient, which may cause negative pressure pulmonary edema. To detect this malfunction, the APL valve is opened fully to a properly connected and set scavenging system. Breathing system pressure should not increase or decrease significantly when the oxygen flow is minimal or when the oxygen flush valve is kept open. A malfunction in the scavenging system is indicated by either excessively high or subatmospheric pressure.
12. Test Ventilator Systems and Unidirectional Valves
By attaching a second breathing bag to the Y-piece to simulate a patient's lungs, proper cycling of the mechanical ventilator and proper flow of gas through the breathing system, including proper function of the unidirectional valves, are checked. If the ventilator bellows progressively collapses during this step, suspect a leak in the ventilator hose, or other problem with the bellows assembly. Make sure the second breathing bag (simulated lungs) is supported by holding the Y-piece. Squeezing the bag during this check allows gas to escape through the ventilator pressure relief valve, and the ventilator bellows will not ascend to its baseline position, which creates the appearance of a ventilator hose leak when actually there is none. Flow of gas through the breathing system is also checked in the "bag' mode.
13. Check, Calibrate, and/or Set Alarm Limits of all Monitors
The intent of the Checkout Recommendations is to verify that the anesthesia machine is functioning correctly. Because of the large variety of different makes and models of monitoring instruments currently used in anesthesia practice, specific recommendations for checking each monitoring instrument is beyond the scope of this document. Nonetheless, properly functioning monitoring instruments is a prerequisite for the 1992 Checkout Recommendations to be valid. Checks of the monitoring instruments and any necessary calibration should be conducted daily or according to manufacturers' specifications.
14. Check Final Status of Machine
The user sets the controls of the anesthesia machine so that it is ready for clinical use.
Dr. Good is from the Department of Anesthesiology, University of Florida, Gainesville. Address correspondence to: Editorial Office, Department of Anesthesiology, University of Florida College of Medicine, Gainesville, FL 32610-0254.
1. March MG, Crowley JJ. An evaluation of anesthesiologists'
present checkout methods and the validity of the FDA checklist, Anesthesiology
Back to Table of Contents
Emergency Ventilation Equipment
* 1. Verify Backup Ventilation Equipment is Available & Functioning
High Pressure System
* 2. Check Oxygen Cylinder Supply
a. Open 02 cylinder and verify at least half full (about 1000 psi).
b. Close cylinder.
* 3. Check Central Pipeline Supplies
a. Check that hoses are connected and pipeline gauges read 45-55 psi.
Low Pressure System
* 4. Check Initial Status of Low Pressure System
a. Close flow control valves and turn vaporizers off.
b. Check fill level and tighten vaporizers' filler caps.
c. Remove 02 monitor sensor from circuit.
*5. Perform Leak Check of Machine Low Pressure System
a. Verify that the machine master switch and flow control valves are OFF.
b. Attach 'Suction Bulb' to common (fresh) gas outlet.
c. Squeeze bulb repeatedly until fully collapsed.
d. Verify bulb stays fully collapsed for at least 10 seconds.
e. Open one vaporizer at a time and repeat 'c' and 'd' as above.
f. Remove suction bulb, and reconnect fresh gas hose.
* 6. Turn On Machine Master Switch
and all other necessary electrical equipment.
* 7. Test Flowmeters
a. Adjust flow of all gases through their full range, checking for smooth operation of floats and undamaged flow-tubes.
b. Attempt to create a hypoxic 02/N20 mixture and verify correct changes in flow and/or alarm.
* 8. Calibrate 02 Monitor
a. Calibrate to read 21 % in room air.
b. Reinstall sensor in circuit and flush breathing system with 02.
c. Verify that monitor now reads greater than 90%.
9. Check Initial Status of Breathing System a. Set selector switch is in "Bag' mode.
b. Check that breathing circuit is complete, undamaged and unobstructed.
c. Verify that C02 absorbent is adequate.
d. Install breathing circuit accessory equipment to be used during the case.
If an anesthetist uses the same machine in successive cases, these steps need not be repeated or may be abbreviated after the initial checkout.
10. Perform Leak Check of the Breathing System
a. Set all gas flows to zero (or minimum).
b. Close APL valve and occlude Y-piece.
c. Pressurize breathing system to 30 cm H20 with 02 flush.
d. Ensure that pressure remains at 30 cm H20 for at least 10 seconds. Scavenging System
11. Check APL Valve and Scavenging System
a. Pressurize breathing system to 50 cm H20 and ensure its integrety.
b. Open APL valve and ensure that pressure decreases.
c. Ensure proper scavenging connections and waste gas vacuum.
d. Fully open APL valve and occlude Y-piece.
e. Ensure absorber pressure gauge reads zero when: -minimum 02 is flowing, and 02 flush is activated.
Manual and Automatic Ventilation Systems
12. Test Ventilation Systems and Unidirectional Valves
a. Place a second breathing bag on Y-piece.
b. Set appropriate ventilator parameters for next patient.
c. Set 02 flow to 250 ml/min, other gas flows to zero.
d. Switch to automatic ventilation (Ventilator) mode.
e. Turn ventilator ON and fill bellows and breathing bag with 02 flush.
f. Verify that during inspiration bellows delivers correct tidal volume and that during expiration bellows fills completely.
g. Check that volume monitor is consistent with ventilator parameters.
h. Check for proper action of unidirectional valves.
i. Exercise breathing circuit accessories to ensure proper function.
j. Turn ventilator OFF and switch to manual ventilation (Bag/APL) mode.
k. Ventilate manually and assure inflation and deflation of artificial lungs and appropriate feel of system resistance and compliance.
l. Remove second breathing bag from Y-piece.
13. Check, Calibrate and/or Set Alarm Limits of all Monitors
** Capnometer Pulse Oximeter
** Oxygen Analyzer Respiratory Volume Monitor (Spirometer)
** Pressure Monitor with High and Low Airway Pressure Alarms
14. Check Final Status of Machine
a. Vaporizers off.
b. APL valve open.
c. Selector switch to "Bag".
d. All flowmeters to zero (or minimum).
e. Patient suction level adequate.
f. Breathing system ready to use.
Back to Table of Contents
by Ellison C. Pierce, Jr., M.D
E. S. (Rick) Siker, M.D. assumed the newly created position of Executive Director of the Anesthesia Patient Safety Foundation in July and was officially welcomed at the APSF annual meeting in New Orleans October 16.
Dr. Siker completed his undergraduate education at Duke University and received his M.D. degree from New York University. Training in anesthesiology at Mercy Hospital, Pittsburgh, and a research fellowship in internal medicine at the University of Pittsburgh were followed by a year as faculty in the Department of Anaesthetics, University of Wales, Cardiff. Dr. Siker, Chairman of the Department of Anesthesiology at Mercy Hospital from 1962 through 1992, was the founding Secretary of the Anesthesia Patient Safety Foundation.
Dr. Siker was President of the ASA in 1973, presented ASA's Rovenstine Lecture in 1981 and received ASA's Distinguished Service Award in 1983. He served as Secretary-Treasurer and then President of the American Board of Anesthesiology, was the first President of the Association of Anesthesia Program Directors and chaired the Executive Committee of the World Federation of Societies of Anesthesiologists. Dr. Siker was elected to Honorary Fellowship in the Faculty of Anaesthetists of the Royal College of Surgeons of England in 1976 and of Ireland in 1988.
He has been a Visiting Professor at more than 90 Medical Schools in the United States and abroad, has presented numerous eponymous lectures, and has authored more than 80 publications. His special research interests have included narcotics, pain pathways, and anesthesia equipment. He derives great pleasure from the achievements of more than 200 anesthesiologists who received their training in his department. Most recently, his principal interests have been concerned with the many facets of patient safety. The APSF is delighted to have Rick as its Executive Director.
Dr. Pierce is APSF President.
Dr. E.S. Siker
Back to Table of Contents
Reflections on Patient Safety
To the Editor
One of the big factors affecting patient safety today is the problem of the substance-abuser being allowed to continue to administer anesthetics and to be responsible for patients' lives. I have been at institutions (hospitals) in my career, where I had become aware that the CRNA was abusing drugs while administering a general anesthetic. Needless to say, the rest of the staff learned what happened and the person, usually a repeater, would be sent off to the rehab place on a little six week vacation, and then returned to the fold. In discussing this situation with peers, most of us felt we would not even let these CRNAS put us to sleep, let alone anyone we loved. You are always aware of your drugs, too, when these people relieve you (that is if you feel comfortable enough to let them). With the repeat abusers also signing your charts, they may involve you in any liability on their parts also. I believe substance abusers in the medical field, who have been in a high position of trust and who have accessibility to narcotics, etc., should go to 0 just like we insist our common folk do after being caught in possession of marijuana or cocaine. I also believe that part of the anesthesia consent should be to inform the patient that the CRNA and/or anesthesiologist was a former substance abuser.
Another situation that I feel needs looking into is the preparation of the patient for colonoscopy and gastroscopy. In many hospitals these days, the patients are given sedation during these procedures, having IV's started, and being monitored for BP, HR, and oxygen saturation. Yet, these patients who are done as outpatients have no lab work, EKG, or chest film. Not all of these patients are classified ASA 1. The risk is that patients come in who are in poor health and former CABG patients with no labs or EKGs. I feel more needs to be done to address that issue. These procedures are indeed stressful to these patients and proper lab work and at least an EKG would serve as a beneficial guideline to prepare for anything unforeseen happening.
Mary R. Locke, CRNA Dearborn, MI
Back to Table of Contents
Expansion of the eligibility for APSF sponsored safety research grants occurred at the Annual Meeting in October.
In August of 1992, the directors of all anesthesiology residency programs received notice of APSFs "Young Investigators Award.' The grants of $18,000 will be awarded to successful candidates who will pursue the six month "Clinical Scientist Track' of the CA-3 year in research related to anesthesia safety. An application form accompanied each letter.
In response to numerous queries about the availability of such support during a 'true fellowship' or CA-4 year, the issue was discussed at the October meeting of the APSF Board of Directors. At that time, modification of the specifications for the grant was unanimously adopted and they now include six months of research in either the CA-3 or CA-4 year.
E. S. Siker, M.D.
Anesthesia Patient Safety Foundation
Back to Table of Contents
The Anesthesia Patient Safety Foundation Newsletter is the official publication of the nonprofit Anesthesia Patient Safety Foundation and is published quarterly at Overland Park, Kansas. Annual membership: Individual $25.00, Corporate $500.00. This and any additional contributions to the Foundation are tax deductible. @Copyright, Anesthesia Patient Safety Foundation, 1992
The opinions expressed in Ns newsletter are not necessarily those of the Anesthesia Patient Safety Foundation or its members or board of directors. Validity of opinions presented, drug dosages, accuracy and completeness of content are not guaranteed by the APSF.
AFSF Executive Committee:
Ellison C. Pierce Jr., M.D., President; W. Dekle Rountree Jr., Vice-President; David M. Gaba, M.D., Secretary; Burton A. Dole, Jr., Treasurer; Casey D. Blitt, M.D.; Jeffrey B. Cooper, Ph.D.; Joachim S. Gravenstein, M.D.; E.S Siker, M.D.
Newsletter Editorial Board:
John H. Eichhom, M.D., Editor, David E. Lees M.D. and Gerald L. Zeitlin, M.D., Associate Editors; Stanley J. Aukburg, M.D. Jan Ehrenwerth, M.D., Nancy Gondringer, C.R.N.A.; Jeffrey S. Vender, M. D., Ralph A. Epstein, M.D., Mr. Mark D. Wood.
Editorial Assistant Ms. Nola Gibson
Address all general, membership, and subscription correspondence to:
Anesthesia Patient Safety Foundation
520 N. Northwest Highway
Park Ridge, IL 60M
Address Newsletter editorial comments, questions, letters, and suggestions to:
John H. Eichhorn, M.D.
Editor, APSF Newsletter
Department of Anesthesiology
University of Mississippi Medical Center
2500 North State Street
Jackson, MS 392164505
Back to Table of Contents