Volume 7, No.1, 1-12 Spring 1992
Table of Contents

Latex Allergies Causing More Anesthesia Problems
New Electronic Checklists Aim at Decreasing Anesthetist Errors
European "Workstation" Rules Will Influence U.S. Anesthesia Machines
From the Literature: Safety in Practice
MN County Studied Intensely for Anesthesia Complications
APSF Sponsored Simulator Research Aims at Reducing Errors
APSF Director David Lees Given FDA Award
Simulators Enter the PACU
Letters to the Editor

Latex Allergies Causing More Anesthesia Problems

by Suzanne Parisian, M.D.

The FDA MEDICAL BULLETIN of July, 1991 carried a 'Health Alert' notifying clinicians of allergic reactions in patients and health care workers caused by exposure to latex-containing medical devices. The report was prompted by the growing number of reports of unanticipated severe reactions following exposure to latex-containing products and medical devices. Reported reactions have ranged from mild urticaria to full-blown systemic anaphylaxis. Latex is a component of many medical devices found in both the operating room and the hospital environment, including: surgical gloves, catheters, endotracheal tubes, anesthesia masks, catheter tips, iv administration sets and syringe barrels.

The exact etiology of the latex allergic response has not been elucidated. However, the water soluble proteins of latex appear to be the primary allergen. The FDA is interested in developing standard assays for measuring these proteins and it has issued an industry 'guidance to manufacturers' to try to reduce levels of leachable protein in latex medical devices.

Mention of an anaphylactic reaction during general anesthesia usually conjures up in the anesthesia provider's mind a drug-related allergic reaction. However, it has been estimated in one study that as many as 10% of patients evaluated for a history of an intraoperative anaphylactic reaction have had an allergic reaction caused by exposure to a latex-containing medical device (1)

Some of the facts known about latex anaphylaxis risk are:

1. Health care workers, individuals with a history of atopic disease, or individuals with prior reactions to latex consumer products or medical devices appear to be at a higher risk for having intraoperative allergic reactions.

2. Patients can have an allergic reaction after having had prior uneventful anesthesia.

Repeated exposure to latex products has been postulated as an explanation for the apparent increase in sensitivity to latex. It has been reported' that the groups showing the highest risk of developing a latex allergy were operating room personnel (7.5% risk for physicians, 5.6% risk for nurses) and dental personnel (13.7/. risk). These groups had a higher incidence than other hospital employees (1.3% risk) or the general population (0.8%). One common scenario describing a person with a potential latex allergy is that of the medical worker who, suspecting an allergy to gloves, switches glove brands frequently unless he/she finds a glove that can be tolerated. Rarely do these people seek diagnostic or allergy testing or consultation by a physician.

Another known population at high risk for developing intraoperative allergic reactions to latex is patients with a history of frequent exposures to latex during multiple surgical procedures and/or routine care of a dysfunctional bladder or colon. This includes patients with meningomyelocele, spina bifida, and other congenital abnormalities, especially those involving the genitourinary system. Approximately 18% 40% of spina bifida patients have an allergy to latex. (2) These patients are repeatedly exposed to latex via urinary catheters, barium enema tips, surgical gloves, intravenous tubing, and syringes used in their routine care.

Preoperative management of patients at high risk for a latex allergy is the same as for any other allergy. Foremost is the need to avoid exposure to known or strongly suspected allergens. Treatment protocols recommended by the CDC include combined administration of H2-blockers, corticosteroids, and diphenhydramine hydrochloride during the 24-hour period before and after all scheduled surgical procedures.(3) Therefore, it is imperative that attempts be made to appropriately screen patients preoperatively to identify high risk candidates. A thorough preoperative history should include questions about possible latex allergies. Patients should be specifically questioned about itching, erythema, swelling or wheezing after wearing latex medical or household gloves, during dental or medical exams where latex products were used, while using latex containing devices or even after inflating balloons. Patients with spina bifida, congenital genitourinary problems, and a history of multiple surgical procedures should be considered potentially at high risk for a latex allergy. Known latex allergic individuals should be encouraged to carry "MedicAlert' type warnings.

Perioperative management of a latex allergy centers on avoidance of latex-derived products. These products include latex-containing gloves, old-style endotracheal tubes, certain airways, tubing, and catheters. Recommendations that have appeared in the literature to decrease latex exposure include using a Bain circuit with a plastic mask, plastic endotracheal tubes, glass syringes, fluids stored in plastic bottles, intravenous tubing free of rubber ports and administering drugs drawn up directly from glass ampules. All surgical gloves touching the patient should be non-latex. Within the anesthesia machine itself, it is not currently feasible to change the components made of latex such as the ventilator bellows.

During anesthesia, the symptoms of latex anaphylaxis present typically within 30 minutes (but can range from 10 to 290 minutes) following anesthesia inductions The symptoms of anaphylaxis to latex may not correlate with the administration of a drug. The CDC MORBIDITY AND MORTALITY WEEKLY REPORT of July 5, 1991 noted that the anaphylactic reaction to a latex containing medical device begins 30 minutes after the start of the general anesthetic and often prior to the surgical incision. The reaction can be life threatening, with symptoms progressing rapidly over 5 10 minutes. The medical management is the same as for any other allergic reaction. However, the symptoms have to be recognized as resulting from an allergic reaction. Inquiries received by the FDA reflect a growing concern about the mechanics of creating a latex-free environment within the operating suite. Presently, manufacturers are not required to routinely identify their products as containing latex. Therefore, when in doubt, operating room personnel must call individual product manufacturers for this information. Private corporations, health care personnel organizations such as the American Association of Nurse Anesthetists, and the FDA are trying to develop a protocol for the safe administration of anesthesia to the latex-sensitive patient.

The FDA is asking health professionals to report incidents of adverse reactions to latex or other materials used in medical devices. To report, an incident, call the FDA Problem Reporting Program, operating through the U.S. Pharmacopeia toll-free number: 800-638-6725. For questions about FDA activity related to latex sensitivity and anesthesiology, call Claudia Gaffey, M.D. or Suzanne Parisian, M.D., Office of Health Affairs, Center for Devices and Radiological Health, at (301) 427-1060.

For a single copy of a reference list on latex sensitivity, write to : LATEX, FDA, HFZ-220, Rockville, MD 20857.

Dr. Parisian is Medical Officer, Center for Devices and Radiological Health, Office of Health Affairs, U.S. Food and Drug Administration


1. Leynadier F, Pecquet C, Dry J. Anaphylaxis to latex during surgery. Anaesthesia. 1989; 44: 547-550

2. U.S. Food and Drug Administration Medical Alert. MDA91-1. Rockville, Maryland. March 29,1991

3. CDC. Anaphylactic reactions during general

anesthesia among pediatric patients United States, January 1990 January 1991. Morbidity and Mortality Weekly Report. 40:26 (July 5, 1991),437

4. Swartz JS, Gold M, Braude B, Dolovich 1. Gilmour R. Intraoperative anaphylaxis to latex: An identifiable population at risk. Canadian Journal of Anesthesiology. 1990; 37: S131

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New Electronic Checklists Aim at Decreasing Anesthetist Errors

by J. M. Feldman, M.D., G. Blike, M.D. and KH. Cheung, M.S,

Human error is increasingly recognized as a major cause of mishaps during anesthesia which result in patient injury. (1,2) Numerous strategies for reducing the likelihood of making an error have been proposed. Some examples of these strategies are: thorough preparation prior to anesthesia, development of meticulous work habits, and improved training procedures.(3) As long as humans provide anesthesia care, we will have the benefit of sensory and reasoning abilities unmatched by any machine, but also the potential for error. No amount of training and effort on the part of the individual can eliminate error completely. Decision support tools to aid the clinician therefore have great potential for helping to avoid accidents due to human error.

The aviation industry has utilized checklists for some time in an effort to reduce the contribution of human error to accidents. Pilots are required to use checklists for executing routine protocols to insure adequate preparation for each phase of flight. In addition, checklists are used for problem solving when incidents occur in flight so that important steps in addressing the problem are not overlooked. Indeed, the Federal Aviation Administration mandates the use of checklists in the cockpit. (4)

Checklists and Anesthesiology

The experience with checklists in anethesiology relates primarily to the pre-anesthesia equipment check. Studies evaluating the utility of this checklist have demonstrated a reduction in equipment-related incidents after adoption of a normal pre-anesthesia checklist.(5,6,7) . Chopra et al. recently published a description of their efforts to use the checklist paradigm to deal with errors in the operating room.(8)

An electronic checklist system has been developed which expands the checklist paradigm to include not only the pre-anesthesia checklist but also a number of additional protocols and problem solving checklists. The choice of checklists has been guided b the desire to: 1) prevent the occurrence of untoward incidents and 2) facilitate appropriate management of intraoperative problems. Errors made in managing problems are commonly due to fixation on a particular (wrong) diagnosis and omission of important steps in diagnosis or therapy. These errors are especially likely when faced with a rare event where the principles of management may not be immediately recalled. The checklist can serve in this instance as a memory aid and a mechanism for insuring that all possibilities are considered.

Electronic versus Paper

One of the frequently asked questions is whether there are clear advantages of an electronic checklist over a paper checklist. The paper checklist is typically constrained for convenience to a single sheet of 8.5 by 11 inch paper. For a single checklist, this paper format may be adequate, but the limitation of a single sheet of paper imposes constraints on the amount of information that can be included. The electronic checklist can provide more extensive checklists and support information in the form of on-line "help" to explain the checklist or provide insights for decision making. When multiple checklists are available, the paper approach becomes at best unwieldy and ultimately inadequate.

Electronic checklists may offer important medicolegal advantages in addition to decision support. Documentation that clinical care was appropriate is often difficult to provide during a malpractice proceeding. The handwritten record may be either illegible or an incomplete rendition of events. The use of an electronic checklist can be documented either in print or by an electronic record keeper. This type of documentation would leave little doubt that care was thorough and up to standard.

The electronic checklist system in use in our operating rooms has been implemented using the PC mode option of the SpaceLabs PC-2 monitor. This option allows for executing software developed by the user on the monitor including use of the touch screen. This option has been a useful tool since it eliminates the need to bring additional computer equipment into the operating room, and the user interface is consistent with that of the monitor.

The most extensive evaluation to date has been accomplished with the pre-anesthesia checklist. This checklist includes not only an anesthesia machine evaluation but also a check for all necessary life support equipment, e.g., resuscitator bag, laryngoscopes, endotracheal tubes and patient suction. The pre-anesthesia checklist is designed to help provide a thorough and efficient preparation for anesthesia. Each step flows logically to the next so that equipment need not be reconfigured many times for evaluation. The total time required to perform this checklist averages about five minutes.

Other protocol checklists developed to date include pre and post-induction checklists, an implementation of the relief protocol proposed by Cooper(9) and a review protocol designed to detect all preventable incidents. Problem-solving checklists focus on infrequent events (e.g., malignant hyperthermia, inspired C02) where memory support is likely to be most useful. Due to the infrequent nature of these anesthetic problems, it has been impossible to collect objective data about checklist utility in the operating room. Experience in aviation has shown that testing methods for preventing error must be done in the simulator environment where a greater number of usually low frequency events can occur. Fortunately, the development of anesthesia simulators makes these types of studies feasible.

Monitoring systems in the operating room have traditionally been used to present only monitored data to the anesthesiologist. These systems already have the potential to store large amounts of information for retrieval. Additional information is often useful to facilitate proper decision making in the operating room. (Every clinician will admit that a quick glance at the ACLS resuscitation algorithms provides a reassuring reminder of the important steps.) The trend toward networked anesthesia information management systems opens the potential to make large amounts of information readily accessible in the OR.

Studies Needed

Given the established, recognition that human error plays an important role in anesthesia incidents, methods to reduce such error must be developed. To date, there has been little if any change in anesthesia practice patterns to address this problem. The use of checklists is a familiar method that has been clearly shown in aviation to play an important role in preventing human error. Application of this approach to anesthesia is logical but studies are needed to ascertain the true utility of checklists for reducing human error.

Drs. Feldman and Blike and Mr. Cheung are from the Department of Anesthesiology, Yale University, New Haven, CT, and presented this material in a scientific exhibit at the 1991 ASA annual meeting.


1. Cooper J.B., Newbower R.S., Long C.D., McPeek B. Preventable anesthesia mishaps: A study of human factors. Anesthesiology 1978;49:399406

2. Gaba D.M.. Human Error in Anesthetic Mishaps. Intemational Anesthesiology Clinics 1989;27:137-147

3. Cooper J.B., Newbower R.S., Kitz R.J. An Analysis of Major Errors and Equipment Failures in Anesthesia Management: Considerations for Prevention and Detection. Anesthesiology 1984;60:34-42

4. Federal Aviation Regulation (FAR) 121.315

5. Charlton J.E. Checklists and Patient Safety (editorial), Anaesthesia 1990;45:425

6. Hunziker P., Koch J.P., Devitt J.H. Formalization and Implementation of an Institutional Preanesthetic Checklist. Canadian Journal of Anaesthesia 1990;37.S9

7. Kumar V., Barcellos W.A., Mehta M.P., Carter J.G. An analysis of critical incidents in a teaching department for quality assurance. A survey of mishaps during anaesthesia. Anaesthesia 1988;43:879

8. Chopra V., Bovill J.G., Spierdijk J. Checklists:

Aviation Shows the way to Safer Anesthesia. APSF Newsletter 1991;6(3):26

9. Cooper J.B., Newbower RS., Long C.D., Philip J.H. Critical incidents associated with intraoperative changes of anesthesia personnel. Anesthesiology 1982;56:4%-461

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European "Workstation" Rules Will Influence U.S. Anesthesia Machines

by Stanley Weitzner, M.D.

Anesthesia equipment standards now being formulated in Europe may well have a significant influence on American anesthesia gas machines in the near future, particularly regarding mandatory monitoring of volatile anesthesia agents and the interrelationships of monitors and their alarms with anesthesia machines.

American anesthesiologists have been active for a quarter of a century in the development of minimum safety and performance standards for anesthesia equipment. As a result, when the International Standards Organization (ISO) Technical Committee on Anesthesia and Respiratory Equipment was approached by European delegations to prepare a safety and performance standard covering the essential requirements of an Anesthesia Workstation for the recently constituted European Economic Community (EEC), a "neutral North American expert" long active in this area (this author) was asked to chair this effort. In September, 1989, the formation of a joint IS0/IEC (International Electrotechnical Commission) working group was approved by the ISO Technical Committee. The working group consisted originally of experts nominated as national representatives from six European community countries plus Japan, Canada, Sweden, the Netherlands, and the United States.

Although there are many extant national and international anesthesia gas machine standards, the anesthesia workstation, for purposes of this European community standard, not only was to include the traditional components of an anesthesia gas machine such as vaporizer, flow control modules, breathing system, absorber, etc. but was also to include such devices as a pulse oximeter, ECC, non-invasive blood pressure monitor and other monitoring and/or protective devices. It was of interest to many of the committee members and others that various practice guidelines developed by different national professional societies (including the American Society of Anesthesiologists) were influential in convincing members of the working group that standards restricted to anesthesia gas machine safety and function only would be inadequate; for example, ECG and temperature monitoring are considered in these standards, although traditionally they are not part of the anesthesia gas machine, nor are they covered in any other anesthesia gas machine standards known.

The concept basic to the entire development of the workstation standard was that each anesthesia workstation is operated with 'delivery system" devices (an 'actuator' that delivers either energy or drugs) and specific, associated devices designed for protection against the hazards from the delivery of this energy or substance to the patient. In other words, the intent was that for every specific delivery system (actuator) there would be a specific 'hazard protection device' associated with it (e.g. when a ventilator is in use, a pressure monitor with a high pressure alarm-the hazard protection device also must be in use).

Development of the new workstation standard is almost complete and it is expected to be submitted soon for ballot by the national delegations within the ISO Committee on Anesthesia. It is assumed that a similar, if not identical, standard then will be adopted by the European Community. The European Community mechanism routinely is charged with adopting, or very closely adapting, an already existing ISO standard, and only as a last resort writing a new standard.

The workstation standard originally was intended to apply to electronically controlled anesthesia gas machines that offer functional integration of both anesthesia delivery and comprehensive monitoring. It was further intended that the apparatus be supplied complete by one manufacturer, or possibly be assembled and integrated by one supplier, or assembled by the user. It should be noted that within U.S. law, each of these three approaches has different, and extensive, legal implications. Repair and service responsibility, product warranty, and FDA regulation would be different in each case. This has been the subject of much debate within the committee. The draft standard calls for the breathing system to have pressure monitoring, exhaled volume monitoring, ventilatory C02 monitoring and expired oxygen monitoring. Prioritized alarms with separate requirements for their audible and visual components are also mandated. The document will take advantage of, and incorporate or modify, existing ISO standards relating to 15/22mm fittings, anesthesia ventilators, gas mixers, and anesthetic gas scavenging systems. In most cases, the relevant ISO standards are very similar, if not identical, to current U.S. (ASTM F-29) standards.

It is the intention, and the agreement, of the member countries, for manufacturers to be able to .certify" that their anesthesia workstation meets the ISO standard's requirements (with an independent "test house" confirming this). Once having achieved ft, manufacturers win be able to sell the apparatus throughout the EEC without restriction and without having to test and certify to 12 or more different national standards. This would offer a very significant commercial advantage since the EEC is one of the world's largest markets.

The standard follows the format of IEC 6011:1988 "Medical Electrical Equipment General Requirements for Safety' and deals with these areas: 1) terminology and definitions; 2) general requirements for electrical safety (e.g. single-fault conditions, operating temperature limits, etc.); 3) general test conditions needed to certify that the anesthesia workstation complies with the standard; 4) identifications, markings, and documents (e.g. color-coding of gas tanks, flowmeters, etc.), as wen as detailed information to be provided by the manufacturer in accompanying documents and manuals provided to the user, 5) sections relating to mechanical strength and stability; vibration and noise; hazards from, and susceptibility to, excessive radiation; excess humidity; accidental leakage of fluids into the workstation; sterilization and disinfection; and 6) requirements dealing with traditional components like gas cylinder and pipeline connections, pressure gauges, etc.

IEC 601-1 is the 'mother document" for most if not all IEC Standards and also is providing the dominant format for ISO and ASTM Standards. Therefore the particular device standard on anesthesia workstations may say, for example, that 'Section I of 601-1 applies unchanged", or 'Section 11 applies with the following additions', or 'Section III applies but with the following deletions," etc. The numbering of the majority of clauses in the standard therefore will be identical to the numbering in IEC 601-1. Sections relating to the particular characteristics of a specific device are added to the standard for that specific device at the end of the sections already numbered within IEC 601-1. One such example is the requirement that limits the surface temperature of an electronic component when it operates in an oxygen-enriched atmosphere. For anesthesia workstations, these additional sections cover such items as gas pipeline connections, flow control systems, flowmeter calibration, vaporizing systems, etc.

In addition, the particular device standard will contain referee test methods that can be used for type testing to determine (certify) that a particular device meets the requirements of the standard. The pervasive influence of IEC 601-1 is so great that the Canadian Standards Association as well as Underwriters Laboratories have begun to change their major standards to parallel or match IEC 601-1.

E.C. Will Differ from U.S.

Details of peculiarities of the new workstation standards, how they differ from U.S. practice, and how they may affect U.S. manufacturers, and consequently U.S. practice, follow.

The most intense and prolonged debate within the working group centered around the question of whether or not the standard should be written to provide for an integrated workstation essentially provided by one manufacturer (or supplier), or one that could be assembled by the user from components obtained from different manufacturers or suppliers. Several paragraphs from the 'Scope" section of the document are quoted here:

"This standard presents essential requirements for an anesthesia workstation supplied complete, as well as essential requirements for individual devices which together make up a complete anesthesia workstation."

"It is the intent of this standard that both complete anesthesia workstations and the individual devices become commercially available to allow users to configure an anesthesia workstation to meet the needs of their clinical practice in conformance with their national regulations. To this end the standard has been structured in such a way as to clearly identify requirements pertinent to specific devices currently available. Different configurations of workstations are illustrated in the document."

"Attention is drawn to recommendations for patient monitoring during anesthesia made by many national, clinical and regulatory bodies. These recommendations include monitoring of the patients' ECG, blood pressure, body temperature, and pulse oximetry."

"NOTE: Although this standard does not mandate the use of the monitoring devices referred to in the paragraph above, manufacturers of Anesthetic Workstations are encouraged to make provisions for such monitors so that the user can more easily assimilate their data output and so that the alarm function of the various monitors can be integrated."

Some Manufacturers Concerned

The above represents the "final" decision of the parent ISO Committee (June 1991) and reflects the voting interest of many small European manufacturers. These manufacturers felt that if only an anesthesia workstation 'supplied complete' were described they would rapidly be excluded from the marketplace. One can readily see how a manufacturer of capnographs or pulse oximeters would have such apprehension. The 'Overview' portion of the document states that the user may assemble the components himself. This is, in actual fact, a complicated task; in the past the melding of different monitors to an anesthesia machine by the user has led to many reported difficulties. It is for this reason that American practice has tended toward fewer manufacturers supplying more and more integrated workstations. As a matter of fact, there are approximately five manufacturers in the world today who can supply an integrated workstation, only two of them based in the United States. On the other hand, the argument has been made that depending on one supplier for all equipment may limit the variety, design, and character of the equipment offered for purchase and thus, in fact, may alter practice.

A clear example of design limitation is the fact that within the standards writing group, manufacturers (who are invited and who do actively participate) proposed and supported what became the requirement of having an anesthetic agent analyzer in use every time an anesthetic vaporizer is in use. The majority of current U.S. practitioner opinion does not favor the mandatory use of anesthetic agent analyzers while administering anesthesia. This is not to argue the analyzer's utility, its potential safety, and its desirability as a teaching tool; literature review simply does not support a high incidence of, nor significant hazard from, vaporizer malfunction. It should be noted that within the ASTM writing group currently generating an anesthesia agent analyzer standard for the U.S., the presence of such an analyzer is not mandated during the administration of inhalation anesthetics.

Gas Analyzers Coming

Nevertheless, because U.S. manufacturers actively sell their anesthesia machines overseas and because of the virtual economic mandate of manufacturing similar models for national and international sales, it appears essentially certain that in the near future, American anesthetists will have no choice but to buy anesthesia gas machines that incorporate anesthetic agent analyzers.

Another contentious point which required resolution by the parent ISO committee related to the requirement (adapted from the existing U.S. ASTM Standard) for mandatory monitoring devices to "be enabled and automatically functioning whenever the anesthesia machine is in use." Related to the issue described above, the question centered on whether or not one could buy a capnograph or pulse oximeter, put it with an existing anesthesia gas machine, and then cause the capnograph or pulse oximeter to be enabled and automatically functioning whenever the anesthesia machine was in use. This is easy to engineer when both the anesthesia gas machine and the monitor are integrated in one frame or supplied by one manufacturer (who provides for the automatic power-on of the monitoring device when the anesthesia gas machine is turned on). When one is dealing with retrofitting an oxygen analyzer, it is also relatively easy to do this. It is merely a question of providing a courtesy or additional electrical outlet at the back or the side of the anesthesia gas machine wired to the master on-off switch. This switch is present on all modern anesthesia gas machines, domestic and foreign. This "automatic enabling' requirement was included for all currently mandated monitoring in the U.S. ASTM Standard because reports in the literature clearly indicated that often appropriate monitors, although in place, were not in use when critical incidents developed. This is a very important concept that is believed by standards writers to provide significantly increased safety.

Despite the many arguments in favor of adopting the automatic-enabling feature in the ISO standard, the vote of the parent committee was slightly different and, thus, the draft standard now states, for example, that the anesthetic gas monitor and its alarm module shall be in operating condition by one of toe following: a) functioning automatically; or b) generating an alarm signal when not enabled or functioning; or c) being enabled and functioning following the pre-use checklist procedure as specified in the standard." It may appear ironic that when the working group voted on this subject, resolution was not obtained because the vote was evenly divided; virtually all of the anesthesiologists voted for automatic functioning and enablement, and virtually all of the manufacturers voted for the system of various different methods to ensure that the monitor is turned on and functions.

This rewording of the originally proposed requirements will not affect the design of U.S. anesthesia machines in any way.

Alarm Priorities

The prioritization of alarms is provided for in the anesthesia workstation standard, calling for alarm characteristics of monitors to be grouped into three categories; 1) high priority, which indicates a condition requiring urgent and immediate action; 2) medium priority, requiring prompt action on the part of the anesthetist and; 3) a low priority alarm which is a signal indicating a condition that the anesthetist must be aware of, but may or may not necessarily respond to (e.g., battery-powered instrument has only one hour of battery supply left). Usually these monitors are provided with both audible and visual alarms, the audible alarms being intended to capture the anesthetist's attention and indicating the degree of urgency with which he should respond, while the visual alarm confirms the alarm situation and points to the probable site or cause of the alarm condition. It is becoming rapidly obvious in this field that the prioritization of alarms will succeed more effectively if, instead of a simple visual alarm, there is a central monitor which can annunciate a brief written message indicating the site or cause of the alarm condition. This type of organization may offer major advantages when multiple (especially stand-alone) monitors are used in combination. Unfortunately, it is not easy or inexpensive to achieve.

"To facilitate data transfer capability between different monitoring devices, a BUS or data transfer system may be used". This is the last sentence of the "Scope" statement of the ISO/IEC draft standard and is the expression of the hope and belief of many of the working group that all anesthesia workstations in the near future will be able to network with other data generators (in the clinical laboratories, recovery room, ICU, etc.) and to be part of a continuous chain of devices that add to, share, manipulate, and analyze relevant patient care information.

Reviewed here are only some of the highlights of the draft ISO standard (which is not yet completely finished, but already twice as long as the U.S. standard). The ISO/IEC working group has yet to settle such questions as the use of "failsafes" or "oxygen ratio controllers" when air is in use, how and what gases should be automatically shut off when the oxygen supply fails, and the accommodation of the monitoring requirements to "closed system (closed-circuit)" anesthesia.

It cannot be emphasized too strongly that this standard will establish de facto the requirements and the design of the Anesthesia Workstation that will be forthcoming in the not too distant future. U.S. manufacturers have already said they cannot afford to manufacture different models for two very different markets. Economically, this standard may functionally set limits to new designs for some time to come. It is vital that the views and technical guidance of the U.S. medical community especially, as well as of U.S. manufacturers, influence this standard as both will have to live with the results of its approval.

Dr. Weitzner is Professor of Anesthesiology at Duke Medical Center, Durham, NC and Chairman of the ISO working group on the anesthesia workstation as well as Secretary of the ASTM F-29 standards committee for anesthesia and respiratory equipment.

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From the Literature: Safety in Practice

Adams, AP: Safety in Anaesthesia Practice, In: Atkinson, RS, Adams, AP (Editors). Recent Advances in Anaesthesia and Analgesia, Vol. 17, Edinburgh: Churchill-Livingstone, 1992,1-24.

In this extremely thorough review of a complex topic, Dr. Anthony P. Adams, Professor of Anaesthetics, United Medical and Dental Schools, Guy's Hospital, London, outlines what would make the ideal safe anaesthesia practitioner. This safe anaesthetist (using the term in the correct traditional sense to mean anyone who administers anaesthesia: physician, nurse, or other) is an intelligent, vigilant individual who is experienced and well rested. He/she uses appropriate monitors at appropriate times. His/her anaesthesia machine is up-to-date and well maintained, having been checked personally by himself/herself. He /she consistently prepares for the unexpected and he/she actively participates in the quality assurance process.

Anaesthesia providers can aspire to and attain this ideal, thanks to the efforts of those clinicians, researchers, and lawmakers whose respective concepts, studies, and legislation advanced patient safety to the forefront in the field of anaesthesia. Professor Adams has extensively reviewed this literature (142 references from the United States and the United Kingdom). His summaries and discussions of this information are well organized and informative.

Subtopics include: The epidemiology of accidents, monitoring standards, checking anaesthesia machines, the selection of anaesthetists, detection of anaesthetic mishaps, the end of flammable anaesthetic agents, fatigue, accountability and audit, competence to practice, product liability, and The Anesthesia Patient Safety Foundation. These discussions demonstrate the very wide range of issues underpinning the field of anaesthesia safety as well as the fact that the struggle to improve patient safety is ponderous, often painful, and still ongoing.

As Professor Adams points out, incredible progress has been made in ensuring the safety of patients undergoing surgery. This progress has not occurred 'by accident,' as anyone who reads this review will appreciate.

Abstracted by: James F. English, M.D.; Clinical Instructor in Anaesthesia, Harvard Medical School; Department of Anesthesia, New England Deaconess Hospital; Boston, MA

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MN County Studied Intensely for Anesthesia Complications

Editor's Note: Recipients of APSF Research Grants are asked to summarize their projects in the Newsletter.

by Mark A. Warner, M.D.

Development of a population-based epidemiologic study of morbidity and mortality related to surgery and anesthesia was carried out with the funding from an APSF Research Grant. Although there have been numerous studies of adverse perioperative outcomes, none has been performed on well-defined, well-described populations.

There is a need to study the anesthesia outcomes of patients in unique populations who undergo anesthesia care because it is difficult to conduct continuous surveillance of persons in referral practices who die or who have morbidities during the extended perioperative period.

Individuals may have been discharged to home or other facilities prior to death or the occurrence of major morbidity, records may be unavailable, or personal contact may be lost. For these reasons, the accurate incidence of these events and the perioperative period over which they occur are infrequently reported. Further, because these are rare events, it is difficult to accumulate sufficient statistics to allow analyses for common ecologies and predictive risk factors.

Factors Unique to Olmsted County

Two factors unique to Olmsted County allow these types of analyses. First, the medical care of all residents of Olmsted County, Minnesota (population 128,W) is continuously monitored and indexed. Over the last 33 years, less than 0.1% of Olmsted County residents have been lost to continuous surveillance of their ongoing medical care. Second, the large anesthetic caseload of the Mayo Clinic and Olmsted Community Hospital of more than 67,000 cases annually provides sufficient numbers of low-frequency events for evaluation of common etiologies and predictive factors.

Specifically, the grant was used to integrate the capabilities of the Mayo Clinic and Olmsted Community Hospital anesthesia databases with the Rochester Epidemiology (Surveillance) Project. Once integrated, the resulting data sets will be used to determine predictive risk factors, common etiologies, incidence, and time course of perioperative mortalities and major morbidities of persons undergoing anesthesia care.

Briefly, multiple local and national data resources have been integrated into a network system with two gigabytes of disk space and served by the Mayo main computer facilities. This integrated system can be used to cross-reference data sources, a very desirable epidemiologic capability. How it works can be shown with a hypothetical retrospective study to evaluate the incidence of pulmonary embolism after abdominal hysterectomy in females greater than 70 years of age, and any association with general or regional anesthetic techniques. For the retrospective study, all patients fulfilling the study population criteria and who received either regional or general anesthetics are identified by the demographic and surgical/anesthetic databases. This group can then be matched against a Master Billing record database to determine those patients who had either a V/Q scan and/or a pulmonary angiogram in the postoperative period. As the number of qualifying patients gets smaller with each epidemiologic sweep, more detailed computerized data can be accessed. For example, complete radiologic interpretations can be retrieved for those patients who had V/Q scans or pulmonary angiograms.

The uniformity of data and the facility and speed of its retrieval have eliminated the labor intensity barriers that have inhibited many such studies in the past. Similar integrated systems can be used prospectively for data retrieval. Patients may be randomized, then followed with minimal delay by using these same databases. Many of these databases have on-line features.

Pilot Projects

Several pilot studies were undertaken to confirm the accuracy of population selection and data retrieval by the integrated system. Clerk verifiers were used to glean selected medical records and surgical schedules for data related to demographics, intraoperative surgical and anesthetic management, and postoperative outcomes (in-hospital and out-of-hospital). These pilot studies identified the strengths and weaknesses of the computerized data. Adjustments and refinements of the systems resulted in marked improvement in data reliability. Specificities and sensitivities of most data components essential for the study of preoperative morbidity and mortality are now greater than 97%.

After the pilot projects, we performed a retrospective study using this system to determine the incidence and outcomes of intraoperative pulmonary aspirations in all patients who underwent elective or emergency general anesthetics from July 1985 to June 1991. This project was not restricted to Olmsted County patients because we wanted to test the data retrieval of the entire system.

Pulmonary aspiration, with bilious secretions or particulate matter present in the tracheobronchial tree, occurred in 62 of 215,488 of these patients (I in 3476); one died intraoperatively from exsanguination during emergency repair of a ruptured abdominal aneurysm. Of the remaining 61 patients, 40 (66%) did not develop either a symptomatic cough or wheeze, hypoxia while breathing room air, or radiographic abnormalities within two hours of pulmonary aspiration. Those 40 patients had no respiratory sequelae. The remaining 21 patients needed intensive care observation for hypoxia and/or pneumonitis. Three of these died from pulmonary insufficiency.

Based on these data, patients with clinically apparent pulmonary aspirations but who do not develop either hypoxia, radiographic abnormalities, or symptomatic, cough or wheeze within two hours after aspiration will probably not have respiratory sequelae. If -any of these findings are present, however, approximately two-thirds of these patients will need ventilatory support and their risk of developing pneumonitis or respiratory distress syndrome is approximately 50%.

The APSF grant provided a portion of the resources used to develop the software for our integrated data system. The grant funded several pilot and preliminary studies to confirm the sensitivity and specificity of the system's electronic data retrieval. Because of the generous support of the APSF, studies which in the past would have been inhibited by the extraordinary time requirements for data retrieval may now be attempted.

Dr. Warner, Mayo Clinic, Rochester, MN was a recipient of a 1990 APSF Research Grant,

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APSF Sponsored Simulator Research Aims at Reducing Errors

Editor's Note: APSF Research Grant recipients are requested to summarize their funded projects upon completion.

by Howard A. Schwid, M.D. and Daniel O'Donnell, Ph.D.

It is estimated that human error is responsible for at least 70% of anesthesia events that lead to adverse outcome. Retrospective analysis of management of critical incidents is limited by difficulty in analyzing the response to the critical incident due to poor record keeping during the crisis, missed information, inaccurate observations, and incorrect sense of time. Due to the low frequency of critical incidents in the operating room, prospective evaluation of the response of a large number of anesthesiologists to these events is not practical.

In an effort to model the clinical setting, we used an anesthesia simulator to create critical incidents in order to observe how anesthesiologists diagnose and treat these situations. This approach provides an opportunity to look for patterns of errors in management. The purpose of this study was to assess the ability of anesthesiologists to recognize diagnostic clues, make the diagnosis rapidly, to affect treatment, and to evaluate the patient's response during simulated critical incidents.

A screen based, graphical simulator that operates on IBM AT or compatible or Macintosh computer was used for the evaluation. The program is called the Anesthesia Simulator Consultant(ASC) and is an expanded version of SIMCORD, the Anesthesia Simulator-Recorder. In these programs, a graphical interface displays the simulated patient and monitors and allows the ,anesthesiologist to examine the patient, administer drugs, control the airway, ventilate, and administer fluids using mouse-controlled input. Mathematical models of physiology and the pharmacologic effects of 70 drugs predict the simulated patient's responses. A variety of patient scenarios and critical incidents can be reproduced with the simulator. The patient's vital signs and all management decisions are automatically recorded for review following the case.

Thirty anesthesiologists (10 residents, 10 faculty anesthesiologists, and 10 anesthesiologists in private practice) were evaluated on their management of six simulated cases. The residents had a minimum of one year of anesthesia training. The faculty anesthesiologists had an average of 7.6 years experience and the private practice anesthesiologists had an average of 8.5 years experience. The six cases were 1) a healthy patient with a full stomach; 2) an elderly, dehydrated patient; 3) an esophageal intubation; 4) a patient who develops myocardial ischemia intraoperatively; 5) an anaphylactic reaction; and 6) a cardiac arrest. None of the subjects knew the type of problem they would confront at the start of each simulation. The subjects were encouraged to vocalize their thoughts during the case; these comments were recorded manually and the individual's actions using the simulator were recorded by the program.

The first two cases on the list did not include preprogrammed critical incidents and provided the subject the opportunity to become familiar with use of the simulator. The authors were present throughout all the simulations to assist subjects with operation of the program.

Many management errors were observed in the study of simulated critical incidents. Both experienced and inexperienced anesthesiologists made significant management errors.

The esophageal intubation was recognized by most subjects either by lack of carbon dioxide on the capnogram or by distant breath sounds with carbon dioxide analysis confirmation. Two residents missed the diagnosis. One thought it was severe bronchospasm and the other thought the capnometer malfunctioned. Myocardial ischemia was often inadequately treated. Tachycardia and hypotension were recognized but were frequently left untreated. In a few instances inappropriate drugs were administered including labetalol and sodium thiopental to treat tachycardia despite hypotension. Continuous infusions of vasoactive agents were especially troublesome. Typical therapeutic dose ranges were not known for a selected agent by 30% of subjects and 50% had difficulty calculating the correct infusion rate in drops/min-1 for the desired mcg/kg-1/min-1.

Anaphylaxis Missed

In the case of simulated anaphylactic reaction, the diagnosis of anaphylaxis was missed 60% of the time. The most frequent incorrect or incomplete diagnoses were supraventricular tachycardia, pneumothorax, and electromechanical dissociation. Several subjects (30%) including experienced clinicians undertreated severe hypotension while trying to find the etiology. In addition, many subjects assumed the tachycardia was due to inadequate anesthesia and administered additional anesthetic agents without checking the blood pressure. Frequent reassessment was found to reduce management errors since anesthesiologists who reevaluated blood pressure at three-minute intervals made significantly more therapeutic errors than those who measured blood pressure more frequently.

Most subjects were not able to recall the initial steps of the Advanced Cardiac Life Support algorithm for the treatment of ventricular fibrillation. The most common errors involved incorrect dosages of medications, incorrect defibrillator use, failure to hyperventilate, and failure to turn off the vaporizer. A clear relationship was found between management of the cardiac arrest and the time since the last ACLS training. Seventy-one per cent of anesthesiologists trained within six months of evaluation managed the arrest according to ACLS guidelines. This number decreased to 33%, 28%,, and 25% for those anesthesiologists with ACLS training in the prior 712 months, 13-18 months, and 19-24 months respectively. No anesthesiologist who had ACLS training more than 24 months prior to evaluation or who never had ACLS training was able to follow the first few steps of the ACLS protocol management of ventricular fibrillation.

Simulation vs. Life

It is recognized that performance in a simulator is different from performance in the real situation. In some cases, performance in a simulator will be better in the simulator and in some cases it will be better in the real world. Heightened vigilance may improve performance in a simulator while unrealistic simulation of the workplace may have a negative impact. Even in a full-scale simulator, fidelity of the mannequin has limitations. The real operating room environment is admittedly very different from the screen-based simulator. It is possible that anesthesiologists' responses to real critical incidents in a real operating room could be different from this screen-based simulator, but we feel the observations concerning management of simulated critical incidents are valid despite the differences between the screen-based simulator and the real situation. Graphical simulation does not account for misinterpretation of absent carbon dioxide in the capnogram after intubation, treating tachycardia without determining the blood pressure, difficulty with calculating infusion rates, or inability to recall ACLS protocols. There is no reason to believe these errors would not have occurred in the operating room under similar circumstances.

Every subject evaluated in this study made at least one potentially dangerous error. Methods must be developed to improve anesthesiologists' readiness for critical incident management. It may be helpful to have simple charts on the anesthesia machine for differential diagnosis and tables for continuous infusions of medications. Based on the poor retention of ACLS protocols six months after training, we propose that anesthesiologists review the management of critical incidents at least every six months. In addition to cardiac arrest, anesthesiologists should be prepared for anaphylaxis, difficulty in ventilating an intubated patient, malignant hyperthermia, pneumothorax, pulmonary embolism, equipment failures, and other emergencies. The preparation can consist of reading and reviewing an organized approach (algorithm) or taking refresher courses covering these incidents. Anesthesia simulators may become an important way to train and retrain for critical incidents. Anesthesiologists can now rehearse the management of these problems with a graphical simulator on a personal computer; in the next few years full-scale operating room simulators may become accessible.

Drs. Schwid, Associate Professor, and O'Donnell, Systems Analyst Programmer, are from the Department of Anesthesiology, University of Washington (V.A. Medical Center), Seattle. They were recipients of a 1990 APSF Research Grant.

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APSF Director David Lees Given FDA Award

David Eric Lees, M.D., a member of the Board of Directors of the Anesthesia Patient Safety Foundation was recently honored by the Food and Drug Administration with the Commissioner's Special Citation and the Harvey W. Wiley Medal.

The awards were presented at a ceremony in Rockville, Maryland by the new Commissioner of the Food and Drug Administration, David A. Kessler, M.D. The medal commemorates Dr. Harvey W. Wiley who is the "Father of the Pure Food and Drug Law.' The original Federal Food and Drug Act was initially known as the "Wiley Act" and was signed by President Theodore Roosevelt in 1906.

The citation of Dr. Lees' achievement reads: For outstanding contribution of time, resources and expertise in assisting the Food and Drug Administration's Anesthesia Gas Machine Pre-Use Checklist Evaluation Project.

The FDA Anesthesia Gas Machine Pre-Use Checklist was first issued in 1986 as an educational adjunct in cooperation with the American Society of Anesthesiologists and the American Association of Nurse Anesthetists, as well as, other interested parties. This generic Checklist provided an organized and rational mechanism for a practitioner to check any machine, old or new, that they might encounter in their clinical practice. Within the last two years the utilization and effectiveness of the Checklist have undergone extensive study and work is presently underway on a revised Checklist that acknowledges the advances in monitoring technology since the introduction of the original Checklist.

Dr. Lees is Professor and Chairman of the Department of Anesthesia at the Georgetown University in Washington, D.C. In addition to his APSF duties as Associate Editor of the APSF Newsletter, he serves as Chairman of the Committee on Equipment and Facilities of the American Society of Anesthesiologists and is a member of the Anesthesia and Respiratory Devices Panel of the Food and Drug Administration.

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Simulators Enter the PACU

Two teams developing anesthesia simulators at Stanford University and the University of Florida are now collaborating under a grant from the Anesthesia Patient Safety Foundation to introduce into the post-anesthesia care unit (PACU) simulator-based training focused specifically on safety.

Physicians and nurses in the PACU face both common and uncommon problems similar to those encountered by anesthesia providers in the operating room. Many may involve respiratory and cardiovascular emergencies requiring quick diagnosis and treatment. The two teams, one in California headed by Dr. David Gaba, the other in Florida led by Dr. Michael Good, will meet with their PACU nurses to generate lists of clinical problems encountered in the PACU and then develop simulator scenarios with which to practice the diagnosis and management of the problems.

For example, a typical scenario might simulate a patient who arrives in the PACU responsive and apparently in good condition. Some minutes later the patient suffers a respiratory arrest accompanied by cardiac arrhythmias. Working through the simulation, the PACU personnel are challenged to diagnose the problem, both by analyzing physical signs as well as by interpreting data from the monitors. The PACU personnel m then practice how to initiate the proper emergency treatment and mobilize the necessary help. Such exercises can easily be expanded to include sessions on the proper use and interpretation of monitoring and other instruments, as well as on respiratory and cardiovascular physiology and pharmacology.

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Letter to the Editor:

Keep Surgeons Away

To the Editor

Regarding the 'In My Opinion' column entitled 'Are Surgeons Needed for Induction?" (Summer, 1991): It is my opinion that they are not only not needed, but are a detriment to patient safety. As soon as the patient is asleep or the block needle withdrawn, they start examining or positioning the patient with little regard for endotracheal tubes, block levels, or the securing of monitors. This is particularly hazardous with small children. Surgery should start after the anesthetic, therefore that is when the surgeon should be present.

Steven W. Singleton, M.D. Dauphin Island, AL

FDA Checklist Seen Lacking

To the Editor

I would like to respond to the article in APSF Newsletter, Fall, 1991: 'FDA Pre-anesthesia Checklist Being Evaluated, Revised" by David E. Lees, M. D. The FDA's decision to streamline the Preoperative Anesthetic Checklist by categorizing the steps in a user friendly format is long overdue and should lead to increased operator compliance with the checkout routine.

The new initial step in the checklist, requiring a resuscitation bag and oxygen tank set-up prior to administering any anesthetic, is critically important. At the University of Mississippi Medical Center, an oxygen tank/resuscitation bag set-up near the head of the OR table has been mandatory for several years and is included in the pre-anesthetic checklist. It is one of the duties of the senior on-call resident to ensure that each OR still contains such a set-up prior to leaving the hospital post call.

The reference to Step 19 of the current Preanesthetic Check list provokes concern. Dr. Lees states-that "while checking to ensure adequate suction is a good work habit, it is not integral to the proper functioning of an anesthetic delivery system.' Recognizing that it is not necessarily a component of the gas machine, I submit that there are few, if any, more important systems that should be present and functional prior to each anesthetic. Abandoning the suction checkout is a radical deviation from conventional wisdom.

I would encourage all anesthetic personnel to familiarize themselves with the new FDA guidelines as soon as these guidelines are available. I would also encourage the continued verification of suction prior to every anesthetic.

V. Rudolph Massey, Jr., M.D.

University of Mississippi Medical Center Jackson, MS

Various Patient Dangers Seen: GI Lab Sedation Requires at Least Education by Anesthesiologists

To the Editor:

It is probably the exception rather than the rule, worldwide, for anesthesia personnel to be present during upper or lower GI endoscopy conducted outside of the operating room. However, patients are usually given a sedative and an analgesic, although the need for this combination of medications for upper GI examinations has been questioned.

Several factors apparently have led to the absence of anesthesia personnel during GI endoscopy. These include: 1) the additional cost to the patient, 2) no perception of need by endoscopists, 3) lack of interest by anesthesiologists, and (4) relatively low risk established by millions of procedures done to date.

Despite the established low risk, published articles have shown that 4f6-threatening events can occur during GI endoscopy, and a number of deaths attributed to the sedative and/or analgesic given to the patient have been reported.

One thing evident from practice is the apparent consensus that many, if not most, diagnostic and therapeutic endoscopies do not need to be done in the operating room and/or with anesthesia personnel in attendance. The role of the anesthesiology department when endoscopies are done in a hospital GI lab should be integrated into quality assurance objectives:

* To assure that appropriate analgesics and sedatives are used in appropriate doses;

* To assure that monitoring is consistent with generally accepted standards;

* To assure that personnel are familiar with the pharmacology of the analgesics and sedatives they are administering;

* To assure that the personnel are trained to deal with emergencies related to analgesic and sedative use and that emergency drugs and equipment are readily available;

* To provide consultation upon request;

* To assist with the introduction of a new sedative, analgesic, or monitoring device.

If the condition of the patient is such that endoscopy must be done in the operating room with a surgeon in attendance, the anesthesiologist should do a pre-anesthetic evaluation and provide monitored anesthesia care.

The specialty of anesthesiology currently may have very limited obligation regarding conscious sedation performed outside of the hospital setting for GI endoscopy. If so, the most significant obligation is an educational one assuring that current information regarding patient monitoring and the pharmacology of new drugs reaches the appropriate audience.

Sita Chokhavatia, M.D Assistant Professor Internal Medicine, Gastroenterology

Y. James Kao, Ph.D., M.D Assistant Professor Anesthesiology

James E. Heavner, D.V.M., Ph.D Professor, Anesthesiology and Physiology Director, Anesthesia Research

Texas Tech University Health Sciences Center Lubbock, TX

Editor's Note: So-called "conscious sedation' administered by non-anesthesia personnel occurs in many other types of procedures as well as GI endoscopy. Readers are invited to share their experience and opinions on the role of anesthesia providers in non-OR sedation administration.

Office Anesthesia Must Meet OR Standards

To the Editor

Recently the Doctor's Company, a large professional liability insurer in California and other Western states, asked my advice about guidelines for conscious sedation in the setting of office surgery. The company was concerned with potential liability of plastic and other surgeons administering sedation/analgesia in the course of performing surgery in the office. The company explicitly did not want guidelines for administration of general anesthesia in the office as they considered the ASA Standards for Intraoperative Monitoring as being applicable in such a circumstance. They felt that adherence to the ASA Standards in the office is the responsibility of the anesthesia care provider.

This stance by a major professional liability insurance carrier reinforces the concept that the administration of anesthesia for office procedures should be performed in accordance with the same standards as anesthesia in the hospital setting. I do not know if other professional liability insurance carriers have the same policy, but any anesthesiologist who practices in the office setting should be aware that if they are not adhering to ASA Standards for intraoperative Monitoring, they may be incurring a significant professional liability risk.

Frederick W. Cheney, MD. Chairman, 1992 ASA Committee on Professional Liability Seattle, WA

Latex Glove Hazard

To the Editor

Routine use of latex gloves by anesthesia personnel during the Administration of general endotracheal anesthesia is now recommended. Recently a piece of such a non-sterile glove was nearly aspirated during anesthesia.

Our patient was undergoing functional endoscopic sinus surgery (FESS) With general anesthesia during which the connection between the endotracheal tube and the anesthesia breathing circuit was hidden by the overlying surgical drapes. At the end of the surgical procedure, it was noted that a torn-off piece of latex glove was caught between the endotracheal tube connector and the anesthesia breathing circuit. The operating room table had been turned at a 90-degree angle to the anesthesia machine and the person administering the anesthesia. Therefore, the piece of latex glove was located 180 degrees from the visual field of the person administering the anesthetic. Fortunately, the piece of glove was observed prior to its potential entrance into the endotracheal tube lumen and consequent aspiration by the patient.

The authors would like their colleagues to be aware of this potential hazard when using latex gloves, which are sometimes poorly fitted. This potential problem might be even more likely to occur should an endotracheal tube be disconnected during an operative procedure and be reconnected in a darkened area "by feel" under surgical drapes.

Janet N. Siler, M.D.

Associate Professor of Clinical Anesthesiology

Gregg Neumann, D.O.

Anesthesiology Resident Hahnemann University Philadelphia, PA

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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 this 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.

APSF 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., Nancy Gondringer, C.R.N.A.; Jeffrey S. Vender, M. D., Ralph A. Epstein, M.D., Bernard V. Wetchler, M.D., Mr. Mark D. Wood.

Address all general, membership, and subscription correspondence to:


Anesthesia Patient Safety Foundation

515 Busse Highway

Park Ridge, IL 60068

Address Newsletter editorial comments, questions, letters, and suggestions to:

John H. Eichhom, M.D. Editor, APSF Newsletter

Department of Anesthesiology

University of Mississippi Medical Center

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