Volume 4, No. 3, pp 25-36
September 1989
Table of Contents

Older Anesthesia Machines Targeted for Component Replacement
Safety Spotlighted at October ASA Meeting
Definition of Terms
Foreign Correspondence: "Wrong Gas" Disaster in Hong Kong
Letters to the Editor
Central Venous Catheter Safety Guidelines Issued by Task Force
Difference in Mask Capnogram Questioned, Explained
Current Questions in Patient Safety: ET Tubes for Laser to Larynx?
Recommendations for Monitoring Standards in the U.K. and Ireland
Monitoring for All Phases of Care

Older Anesthesia Machines Targeted for Component Replacement

Editor's Note: Members of the APSF Education Committee recently discussed a number of issues relative to making older anesthesia machines

safer without necessarily incurring the cost of entirely new equipment. following is a summary of the discussion "resenting the personal opinions of Arthur J.L. Schneider, M.D., Joseph S. Arcarese, Paul E. Berkebile, M.D., J. S. Gravenstein, M.D., Beverly Nichols, CRNA, Peter 1. Schrieber, Terry Spraker, Ph.D. and Charles Witcher, M.D. Comments and opposing opinions are welcome and will be considered for publication in a future issue.

by Arthur J. L. Schneider, M.D.

With the full realization that well understood and maintained older anesthesia equipment is not, by definition, unsafe and that a practitioner accustomed to the limitations of one piece of equipment is probably not a safer practitioner when he uses a now and unfamiliar piece, certain components and features of older anesthesia machines are worthy of consideration for replacement.

At the time of its marketing, older equipment was held to be safe, considering extant education and common practice. However, a hazardous situation may exist if a person accustomed to operating an anesthesia system with modem safety feature uses a piece of equipment of older vintage which does not incorporate the same safety features. Unquestionably, a great deal of time and effort has been expended in an effort to improve the safety and convenience features of modern machines.

Anesthesia machine features to be considered for replacement include: 22 mm Scavenger Connections, ANSI standards have been enacted that require 19 mm diameter hoses and for gas scavenging. Gas scavenging systems originally used connectors of non-standard diameter. The great danger is in using 22 mm hoses, standard for gas delivery, in scavenger applications. Here the unintentional connection of the patient's airway to the negative pressure of the scavenger system can be very injurious. It is preferable to switch to 19 mm connectors.

Vaporizers with Nonstandard Direction of Turn

ANSI standards have advocated, for a decade, that the standard direction of turn to increase the output of calibrated vaporizers should be counterclockwise. Some vaporizers remain in service in which output is increased by a clockwise rotation of the knob. It is extremely disconcerting to discover that a vaporizer manipulation that was intended to reduce or discontinue the administration of volatile anesthetic has, in fact, greatly increased it. Here, again, the problem is more acute with unfamiliar machines. Vaporizers with nonstandard direction of turn should be considered for replacement.

Vaporizer Selection Switches

Older machines which contain flowmeter controlled vaporizers are often equipped with multifunction valves for vaporizer operation. These valves might be used to select a particular vaporizer or to open an oxygen flush valve. This leads to confusion in not always remembering to turn the vaporizer on again after an oxygen flush. In addition, many older machines contain two flowmeter controlled vaporizers that are not interlocked, leading to the possibility that both vaporizers can be turned on at the same time. Problems associated with vaporizer control (selector) valves are eliminated with anesthesia systems designed to accept two or more calibrated vaporizers which are interlocked so that only one vaporizer can be turned on at a time. Anesthesia systems using multifunction vaporizer control valves should be considered for replacement.

Carbon Dioxide Cylinders and Yokes

Modern anesthesia machines have been equipped with safety interlocks in their oxygen/nitrous oxide systems which act to prevent the delivery of gas mixtures containing less than 25 percent oxygen to the common gas outlet. The practice of adding carbon dioxide, or any third gas other than air, to these systems may cause the unintentional administration of hypoxic gas mixtures and is discouraged. Furthermore few, if any, clinical indications for the addition of carbon dioxide to the inspired gas mixture now seem to exist, particularly when intraoperative ventilation is monitored by capnography

Flowmeter Controlled Vaporizers

While there is no doubt that flowmeter controlled vaporizers have been used successfully to administer volatile agents for millions of anesthetics, newer calibrated vaporizers are simply better, safer, and easier to operate. The use of flowmeter controlled vaporizers requires consideration of vaporizer flow, agent partial pressure, diluting gas How, and temperature Calibrated vaporizers provide a single control for agent concentration. When flowmeter controlled vaporizers are used with vaporizer selection switches it is possible to set the vaporizer Dow before establishing the diluting How and to deliver high vapor concentrations to the patient. Similarly, a reduction in dilution flow correspondingly increases the concentration of anesthetic vapor delivered. Although a flowmeter controlled vaporizer can theoretically be used to deliver any volatile agent, this practice has been questioned because of the danger of mixing agents or of using a vaporizer filled with an unexpected agent. Agent specific calibrated vaporizers are a better choice

Vaporizers Downstream of Common Gas Outlet

This arrangement seems to have originated with machines embodying flowmeter controlled vaporizers physically built into the machine. These machines do not have convenient ways to accommodate calibrated vaporizers when they are added. This problem is sometimes resolved by installing the calibrated vaporizers downstream of the common gas outlet. Practice has shown that these installations induce situations where more than one vaporizer can be turned on at any time and that the output of these downstream vaporizers can be affected by use of the oxygen flush valve or by bumping or tipping the vaporizer. The arrangement invites undetected disconnection and is often mechanically unstable; vaporizers should not be placed downstream of the common gas outlet.

Carbon Dioxide Absorber Bypass Switch

Many carbon dioxide absorbers have been produced, and now exist in hospitals, which contain valves that permit the carbon dioxide absorbent to be bypassed. The design purpose of these valves was to permit the replacement of canisters without the loss of gas from the breathing circuit. The valves are also used for the purpose of budding up the carbon dioxide partial pressure within the circuit in order to stimulate spontaneous ventilation. In both instances, the reconnection of the carbon dioxide canister to the rebreathing circuit depends upon resetting the valve when bypass is no longer desired. The danger is in forgetting. These valves are no longer needed and, as they represent a hazard, should be considered for replacement.

Machines with Two Common Gas Outlets Some anesthesia machines, produced in the distant past, had two common gas outlets, the purpose of which was the maintenance of two breathing circuits, each separate, intact, and attached to the machine. Selection of the desired circuit was carried out by means of a se-lector switch that would direct the flow of gas to one outlet or the other. This procedure is no longer in common practice and anesthesia machine performance standards recommend against it. Machines of this type obviously should be considered for replacement in order to prevent mishaps encountered by persons not familiar with their use.

To be sure, old workhorse machines, with vigilance on the part of their operators, have been used in many successful anesthetic procedures. While these machines are still usable, practitioners likely will choose the prospect of safer care with the ease of operation and comprehensive monitoring of both machine and patient available in modern anesthesia systems.

Dr. Schneider is on the staff of the M. S. Hershey Medical Center in Hershey, PA.

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Safety Spotlighted at October ASA Meeting

by Robert A. Caplan, M.D.

Patient safety in anesthesia will once again be a major focus at the American Society of Anesthesiologist's annual meeting in New Orleans, October 14-18. Safety and related subjects have grown into one of the areas attracting the most interest at the meeting. A wide variety of presentations will cover various aspects of patient safety, epidemiology, and education.

Among the refresher course lectures on Saturday, October 14, will be "Anesthetic Disasters and Their Prevention" by Dr. R. Keenan and "Quality Assurance in a Private Practice Setting" by Dr. I Vitez. On Sunday, October 15, Dr. 1. Severinghaus will discuss the uses and limitations of pulse oximetry, followed by a similar consideration of capnography by Dr. M. Good. On Tuesday, October 17, Dr. M. Mulroy will deliver a Clinical Update Lecture entitled, "Preventing Complications of Regional Anesthesia:'

Workshop sessions will feature several related items. A working model of quality assurance will be explored on Monday afternoon. Occupational hazards in anesthesia are addressed in a Tuesday afternoon session. The yearly workshop on educational issues will be held on Wednesday morning.

Nearly 100 presentations will be given during the Patient Safety and Epidemiology Scientific sessions. Simulators and biomechanical issues will be the focus of the Monday morning session. Several investigators will present their experience with a variety of anesthesia simulators that have been adapted for resident training. Preoperative issues will be addressed on Tuesday morning, including a selection of papers on the value of routine laboratory tests. intraoperative complications will be the principal topic of the Tuesday afternoon session.

Wednesday morning will offer two choices: an oral session on postoperative complications and a formal poster session. Hypokalemia caused by pre-induction stress and a possible hormonal link to postoperative nausea are just two of the interesting topics scheduled during this tune period. The final Wednesday afternoon session will focus on educational issues.

This list of presentations at the annual meeting is only a small sample of the many activities related to patient safety. Further details will be available in the meeting materials.

Dr. Caplan of the Virginia Mason Clinic, Seattle, WA is chairman of the Patient Safety, Epidemiology and Education section of the ASA Annual Meeting.

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Definition of Terms

For the record, editorial policy of the APSF Newsletter is to use the traditional (British) understanding that the term "anaesthetist" or "anesthetist" means any practitioner who administers anesthesia: physician, nurse, or otherwise. There is never any intention of implications about Certified Registered Nurse Anesthetists. Individual authors may refer to anesthetists or anesthesiologists depending on the context, but the intention always is that this newsletter exists for the promotion of safe care by all anesthesia practitioners.

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Foreign Correspondence: "Wrong Gas" Disaster in Hong Kong

by Professor Ross Holland

On 14th January, 1989, the 55 year-old owner of a popular Hong Kong night-spot was administered general anaesthesia for open reduction of a tarsometatarsal fracture She was also the wife of a University Professor and popular part-time correspondent for the major English language newspaper in Hong Kong.

After seven minutes of uneventful anaesthesia, a noninvasive blood pressure recorder signaled an unsuccessful reading, and the ECG revealed a bradycardia. Simultaneously, the patient was observed to be "gray" and cardiac arrest was diagnosed.

Cardiopulmonary resuscitation began immediately, and a cardiac output was produced, and the patient's color changed, in that she became blue, rather than gray. Despite vigorous CPR, appropriate pharmacology, and effective ventilation via an endotracheal tube which was proven to be correctly placed, no further improvement occurred in her condition.

The NIBP recorder incorporated the hospital's only oxygen analyzer (it has five O.R.'s), but this function was not in use since it was not routine practice at the time. An oximeter at first showed desaturafion, but during the course of resuscitation gave a number of readings which were at variance with the patient's clinical appearance.

Arterial blood gasses taken approximately ten minutes into the resuscitation showed the following: PaO2 = 2.7 mm HS, PCO2 = 38.7 mm HS, pH = 7.5333, Base excess 9.0, Sat 02 = 0.2%.

Continued efforts at resuscitation were unavailing. About 40 minutes after cardiac arrest was first diagnosed, a patient in an adjoining O.R. was induced and intubated, and immediately became cyanosed. Disconnection of the apparatus and inflation of the patient via the E.T. tube with expired air produced a return to normal color.

A defect in the gas supply was then suspected and the anesthetic apparatus in both O.R.'S converted to reserve (cylinder) supply. The first patient's color now improved, whilst the second maintained normal oxygenation and her operation was completed uneventful.

The first victim, however, did not recover neurological function and died 48 hours later.

Analysis of the contents of a 100 litre vacuum insulated liquid oxygen container, which had been delivered to the hospital and connected to the gas pipeline about one hour before the fatal anesthetic was commenced, revealed that its contents were almost pure nitrogen.

The hospital called the police, and the media took a keen interest in the ensuing events. The subsequent inquest took more than six weeks to hear medical and technical evidence as well as many expert witnesses.

Monitors Not Standard

It was established that standard practice in Hong Kong at the time of the accident did not include the routine use of oxygen analyzers or oximeters, and in fact there were no minimal monitoring standards applying in Hong Kong at all. Many anaesthetists apparently relied entirely on clinical judgement, and the anaesthetist for the surviving patient described above actually spoke strongly against the routine use of any monitoring devices.

The cause of the misfiring of the container was never established, the company maintaining that it was "sabotaged". A feature of the inquiry was a vigorous attack on the anesthetist's clinical management by the counsel assisting the coroner, and the gas company's attorney. Professor James Payne, formerly British Oxygen Professor of Anaesthesia at the Royal College of Surgeons was also critical of the anesthetist's failure to diagnose the cause of the problem.

The court also heard evidence from Ross Holland, APSF member and Professor of Anesthesiology. That previous wrong-gas accidents had almost always been fatal for the first victim to be exposed, and that whatever might be happening elsewhere in the world, right or wrong, the standard of care in Hong Kong at the time of this accident did not include the use of inspired oxygen concentration monitors.

The jury found that there was no medical negligence, and that the sole cause of death was the faulty gas container. A number of recommendations were made, including the routine use of inspired oxygen analyzers during general anaesthesia.

Enormous Costs

The bottom line is that before any liability claim has been heard, much less settled, the cost to the community and various parties involved has already exceeded (U.S.) $1 million, and it all could have been averted by the expenditure of less than (U.S.) $2000 on oxygen analyzers routinely fitted to all five anesthesia machines of that hospital, provided of course, that they were routinely used. Even the cost of providing analyzers for all anaesthesia machines in Hong Kong would have cost less than half of the legal expense for this case so far.

Ever since the accident, the Government health authority has been testing every oxygen container arriving at its hospitals, at the cost of countless man-hours.

The Society of Anesthetists of Hong Kong is now engaged in a program of drafting standards similar to those issued by the Australian Faculty of Anaesthetists, and so far has promulgated two on minimal monitoring standards and minimal facilities for sale anaesthesia in operating suites.

Had these documents been in force before January 1989, not only this accident, but others (such as flowmeter mix-ups) might also not have occurred.

Dr. Holland is Professor and He-ad, Department of Anesthesiology, University of Hong Kong.

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Letter to the Editor:

'Abandoning' PACU Patients to Do Next Case

To the Editor:

I have been following the correspondence on "briefly leaving the patient" with increasing dismay. It seems to me that your correspondents have totally missed an important point.

In general, a physician may not legally (let alone ethically) relinquish responsibility for a patient with whom he has established a patient-physician relationship unless the patient either no longer needs care or has been transferred to the care of another physician.

Although there are some legally created exceptions to this general rule, none of these are relevant to the anesthesiologist-patient relationship. An anesthesiologist who commences the "solo" administration of anesthesia to a patient for an elective case leaving other patients for whom he has accepted responsibility in the Recovery Room without the immediate availability of another appropriately skilled and qualified individual to render needed emergency care is, in my mind, already guilty of abandoning those patients. The question raised, therefore presupposes a situation in which he had already (in my view) seriously transgressed against the ethics of our profession due to the lack of PACU coverage. His dilemma is artificial because it arises out of his choice to place himself in that situation.

Peter R. Fletcher, M.A., B.M. B.Ch. (Oxon), M.R.C.P. (U.K.), Drexel Hill, PA.

Letter to the Editor: Drug Accident Shows Need for Label Standards

To the Editor:

"The best laid schemes o' mice and men gang aft a-gley."

In the December, 1987 issue of the Anesthesia Patient Safety Foundation Newsletter an article entitled "Better Labels Will Cut Drug Errors" detailed the efforts of the D4267 Committee of the American Society for Testing and Materials (ASTM) to reduce medication errors by improving labeling, legibility, and color coding of anesthetic drugs.

The author of the article, Dr. Leslie Rendell-Baker, noted, however that even with the efforts of the ASTM committee, "There still remains the manufacturer's tendency to adopt labels designed to identify dearly all their own products rather than using different designs for each group of products".

A recent event at a university hospital in the Northeast illustrated Dr. Rendell-Baker's point all too well. A resident from another training program was accepted for a one month cardiac anesthesia rotation at the university program. The resident prepared the room and drugs according to the university hospital's protocols, but, unfortunately (unknown to the staff at the university hospital), the resident brought his own drug labels from his parent program. The resident's parent program continued to use the older non-ASTM color coded anesthesia drug labels, whereas the university hospital program used the ASTM D42 67 anesthesia drug labels. During the conduct of the anesthetic, the university hospital attending physician supervising the resident accidentally administered an incorrect drug, assuming that the syringe has been labeled according to the university hospital protocol.

Obviously, several errors were made. The resident should not have brought materials, be they drugs, equipment or labels, from another hospital and the attending physician should not have given anesthesia "by colors". It does illustrate, however, the point that primary reliance on a backup safety mechanism may act to your detriment. This standard is not meant to preclude reading and confirming the syringe or vial labeling. In aviation safety circles, this is referred to a "primary backup inversion", where the primary system which is the human and human vigilance become the backup system and the backup system (color coding) becomes the primary.

The bigger problem and question, however, is why several years after the standard had been published, a major manufacturer still produces "the familiar colors" that have been "traditionally supplied" to the anesthesia community as well as the "new color code standards"? The manufacturer would only make the older product if there was still a demand within the anesthesia community. Obviously, more information on the new standard is necessary. Practicing anesthesiologists must purchase the new labels and manufacturers should withdraw the older labels from the marketplace.

It is not enough for organizations to participate in the drafting of voluntary consensus standards; once completed and endorsed, these standards must be publicized and marketed to both consumers and manufacturers.

David Eric Lees, M.D., Professor and Chairman, Department of Anesthesiology, New York Medical College.

Letters to the Editor: Radiation Hazards; Protocols

To the Editor:

The June 1988, APSF Newsletter contained a question concerning conduct during x-ray or fluoroscopy. Dr. Jene notes ..... protected area a few feet from the patient." Please define "a few feet." During angiography, CAT scan, etc., there is a crowd behind the shield. You might check with your radiology safety officer regarding lead aprons or portable shields during some high energy procedures. With some equipment I gather there can be a bit of spread and bounce in the rays.

The next question to be addressed concerns tumor high energy bombardment. How many and what monitors are essential? How many TV cameras are necessary? Offer suggestions for protocols for shutting down the therapy unit so the chamber can be entered (perhaps they were pulling my leg, but I can remember the radiologists telling me that the unit would be damaged if suddenly "switched off").

As a side issue or question, there is the problem of moving a sick patient, under anesthesia, with abdomen open, after a debulking, from the operating room to the bombardment unit. How many hospitals have the luxury of having the unit near the O.R. and on the same floor? Perhaps minimum conditions should be established to remove the pressure from anesthesiologists who are forced to perform under conditions that are dangerous because "that's the way it is here".

John B. Stetson, M.D. Adjunct Professor Purdue University

Editor's Note: Replies and suggestions in response to Dr. Stetson are welcome.

Swiss Check Lists Suggested

To the Editor:

While reading the December, 1988 issue of the Anesthesia Patient Safety Foundation Newsletter, I saw your offer for the APSF Clipboard. I would like to share with you our approach to an anesthetic checklist.

Mishaps and catastrophic events are mainly caused by failure to adhere to safety standards. The most vulnerable points in delivering safe anesthesia are preoperative evaluation, moving patients from anesthetic room to operating theatres and back to recovery, and relieving other anesthetists.

We have designed check procedures especially for these risk periods, and grouped them together on a DIN A4 sheet (see copy below), which is attached to the anesthetic clipboard.

We have not yet quantitated acceptance and increase in quality cam but there is the distinct impression, that our checklist helps resident and staff members maintain the required standard of care by spending less time per case, thus, leading to increased efficiency.

Hans-Gerhard Schafer, M.D. University of Basel

Basel, Switzerland

Letters to the Editor:

Australian Anesthesia Assistants Well Trained; Benefits to Care Noted, Appreciated

Editor's note: The September issue contained a discussion of the suggestion that an assistant is essential during administration of anesthesia and a listing of the Australian policy on minimum assistance for the safe conduct of anesthesia. A December editorial advocated these assistants be utilized mainly in the U.S. This letter follows up with a discussion of the training of some of these assistants.

To the Editor:

Anesthetic assistants in the state of Queensland, Australia have ousted since the State Health Department approved a course to be conducted by the Royal Brisbane Hospital (R.B.H.) in January, 1978 and this course has been conducted every year since. The duration of the course is two years and, after graduation, the anesthetic assistants are presented with a hospital certificate and badge. About 50 anesthetic assistants are employed in hospitals throughout this state. Most are employed under the department of anesthetics and are responsible to the medical superintendent via the senior assistant and director of anesthetics.

These assistants are trained to dean, prepare, and setup the equipment along with assisting the anaesthetists in the operating rooms during anesthetic procedures. In the large hospitals, an assistant is provided in the intensive care units to attend to the ventilators and circuits and carry out other anesthetic-related duties.

This category of staff was introduced as a result of the many problems that were being experienced by the anaesthetists. Nursing staff had been filling this role prior to 1978 and very often the nurses were being changed about on a daily basis. Some days the anaesthetists found they had no assistant at all, while on other days they would he given a junior student nurse who didn't know a magill forcep from a laryngoscope. On some occasions, the anaesthetists would have to clean their own equipment before they could start an anesthetic.

Now there are permanent trained anesthetic assistants and some trainees working in the operating rooms. The anaesthetists take part in the training course by giving lectures and practical demonstrations. The assistants My setup the anesthetic equipment including arterial lines and other special equipment before the anaesthetists arrive to start the anesthetic. As the assistants monitor the working of the equipment, very seldom will faulty equipment find its way into an operating room. Some of our assistants previously were enrolled nurses, orderlies, and some came from other areas such as students and ambulance bearers. The anesthetic department interviews all applicants for assistant positions.

Any person with the required qualifications can apply to do the course. This included nurses of all categories. All do the full two years of training. The trainees are employed full-time at the hospital while carrying out full-time anesthetic duties. In Queensland, 11 large hospitals have anesthetic assistants, while some other hospitals have nurses of various experience. Some smaller hospitals don't have either and the anesthetists are left to go it alone without any assistants.

There is great support for assistants from the various anaesthetists and the course at R.B.H. is supported strongly by the anesthetic department.

We provide one assistant to every two operating rooms; however, this at times is not enough especially if the procedures are major ones. There is always the anesthetic work-room assistant that can be called upon if necessary.

The training program is expanding with more outside hospitals wanting to take part and other hospitals now employing the newly-trained assistants. The anesthetic assistants at R.B.H. now play an important role in the practical experience to the post-basic theater nurses' experience in the anesthetic field, assistants demonstrate to the course nurses the checking and setting-up of anaesthesia equipment.

The assistants do not give anesthetics, intubate or cannulate. The legal responsibility is taken by each anesthetic. These assistants were introduced to provide trained assistance to the anesthetists in any area where anesthetic procedures were being conducted.

In conclusion, I must state that I have received many comments from anaesthetists during my ten years at R.B.H. and no anaesthetist has ever stated their concern of assistants being a liability. Many comments are of the appreciative type, along with positive support for assistants to be introduced into areas of hospital resuscitation teams and casualty departments.

Mr. K.P. Kerrisk, Senior Anesthetic Assistant, Royal Brisbane Hospital, Queensland, Australia.

Anesthesia Care Team Concept Questioned; Aviation Analogy Faulted

To the Editor:

Dr. Rauscher employed the aviation/anesthesia analogy in a recent letter (March 1989 Newsletter) to argue in favor of the Care Team approach in anesthesia. As an active anesthesiologist, pilot and flight instructor I believe that I see the limits of this analogy more clearly than others.

It is difficult to argue against the potential utility of another's help with the performance of complex tasks in either aviation or anesthesia. However, a few points should be kept in mind. first, no airline captain endeavors simultaneously to fly two aircraft with the assistance of two co-pilots. Second, those involved in human factor analysis for aviation have recognized that new technology can so ease the cockpit workload that performance and vigilance may actually suffer due to boredom induced fatigue. Crew reductions have been considered so that each crew member will have enough work to do to keep busy, engaged and alert. This type of problem may exist in anesthesia as well.

Finally, the "crew" concept in aviation is not without its problems. Some airlines have recently introduced new training programs to help crews team to work together more efficiently. These "cockpit resource management" programs specifically deal with the dichotomy of the captain as pilot-in-command with absolute authority and the need for input, suggestions and assistance from subordinates. Such programs do not exist for the anesthesia care team.

If the anesthesia care team implies that two professionals will work together in a well thought out fashion, with appropriate duties and responsibilites for each, while providing anesthesia for a single patient, then the airline analogy may hold; in common anesthesia practice, it does not.

Benjamin H. Gorsky, M.D. Chief Anesthesiologist

Shriners Hospital for Crippled Children Honolulu, Hawaii

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Central Venous Catheter Safety Guidelines Issued by Task Force

by Walter L. Scott, Ph.D.

The Food and Drug Administration (FDA), as well as the Canadian Health Protection Branch (HPB) have become aware of an appreciable increase in the number of complications associated with the use of central venous catheters (CVCs). A multidisciplinary health care task force consisting of physicians, nurses, and manufacturing representatives has concurred that individual health care providers, professional medical and nursing associations and health care facilities need to address the proper placement procedure, follow-up and care associated with these devices.

The Anesthesia Patient Safety Foundation is represented on this task force by Dr. E.C. Pierce. The task force is investigating long-term solutions such as changes in CVC labeling, development of instructional material (including videotapes) and monitoring procedure quality by the Joint Commission on Accreditation of Healthcare Organizations (I.A.C.H.O.). Some aspects of the CVC complications are well understood and the task force wishes to publicize this information in an expeditious manner.

Reports received by the FDA and the HPB regarding CVC complications include, but are not limited to: infection, pneumo-/hemo-/hydro-/ thorax, vessel and cardiac perforation, cardiac tamponade secondary to pericardial effusion, dysrhythmia, air embolus, and sheared catheters. Many of these complications are related to technique and are associated with substantial mortality. The current literature indicates that the number of CVC related problems are conservatively estimated as high as ten percent of the approximately three million CVCs used annually in the U.S. The following recommendations were made by the task force to help reduce or prevent these complications.

* Central venous catheterization should be performed only when the potential benefits appear to outweigh the inherent risks of the proceduce.

* Except for pulmonary artery catheters, the catheter tip should not be placed in, or allowed to rnigrate into, the heart.

* Catheter tip position should be confirmed by x-ray or other imaging modality and be rechecked periodically.

* Central venous catheterization must be performed by trained personnel, well versed in anatomical landmarks, safe technique and potential complications. Users in training must be closely supervised by qualified personnel to assure their technical expertise prior to independent performance of these procedures. Ongoing monitoring of experienced trainees should he undertaken to assure continued competence.

* Those placing CVCs should be familiar with the specific equipment utilized as well as the proper selection of insertion site and catheter type, size and length.

* Those caring for patients with indwelling central venous catheters should be well informed of the appropriate care and associated complications of CVCS.

* Manufacturers should include specific labeling to address the potential complications of CVC use. Therefore users should read all manufacturers' labels, instructions and warnings, as these contain important and useful information essential for the safe and effective placement of the catheter.

Except in emergencies, catheterization should be performed with M aseptic technique to include hand washing, sterile gloves, masks, hats, gowns, drapes and proper use of a suitable skin antiseptic. Catheters placed in less than sterile fashion should be replaced as soon as medically feasible. As the use of central venous catheters has increased in recent years, so has the prevalence of their associated complications. By following these recommendations the incidence of these complications and resulting sequelae should be substantially

reduced. Users and institutions should review and monitor this clinical activity to assure that the process and outcomes are consistent with high quality patient safety standards.

Dr. Scott is a staff member of the Center for Devices and Radiologic Health at the Food and Drug Administration.

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Difference in Mask Capnogram Questioned, Explained

by J.S. Gravenstein, M.D.

Recently, two colleagues wrote to the APSF that they had observed a discrepancy between end-tidal and arterial carbon dioxide tensions (PETC02 and PaCO2) in children during inhalation anesthesia. The table summarizes their data. It shows large PaCO2-PETC02 gradients during general anesthesia with use of a mask, and quite normal gradients once the children had been intubated and their lungs mechanically ventilated.

The colleagues wondered why the capnometer gave such misleading information during inhalation anesthesia with mask and bag. They also asked whether hypercarbia, as observed by them during induction of anesthesia in children, has deleterious effects.

The measurement of carbon dioxide in respired gas has its vicissitudes. A brief review brings things into focus.

It is often recommended to sample gas for analysis as close to the mouth as possible. Indeed, sampling gas in the airway itself would be ideal. After all, we want information about alveolar gas, because that Ls the best way to represent arterial gas.

Of the exhaled gas, that at the end of a large tidal volume best represents alveolar gas. The first part of the exhalation will come from the mouth and trachea and bronchi, that is from dead space that will have been filled with the last part of the preceding inspiration. We can increase this dead space by putting a mask over the patient's face. With a large dead space and a small tidal volume, the end-expired gas may not contain much or even any alveolar gas.

Anesthesia maneuvers that increase dead space and at the same time decrease ventilation and tidal volume will not only prevent us from detecting alveolar gas, they will also cause arterial carbon dioxide tensions to increase. The difference between P,,CO2 and POC02 will increase, just as it did in the cases reported above. Such findings are particularly likely in patients with relatively small tidal volumes. Furthermore, a leak around the mask will cause dilution of the expired C02 and will increase PaCO2-PETC02.

How can it be detected that there is not a good sample of end-tidal gas? Inspection of the capnogram provides clues. A normal capnogram has a box-like appearance [see figure (reduced dead space, normal tidal volume)]. If the transitions from phase 11 (the upstroke representing the appearance of carbon dioxide in expired gas) to phase III (the plateau), and from phase III to phase IV (the downstroke representing the appearance of fresh gas in inspired gas) are rounded [see figure (increased dead space, reduced tidal volume)], the tidal volume is likely to be too small to bring forth alveolar gas in the end-tidal gas. If phase III of the capnogram has not reached a plateau before it is interrupted by phase IV, expiration may not have run its course, and end-tidal C02 tensions will underrepresent arterial C02 tensions.


Diagram of depressed ventilation and increased dead space (left pair) and normal ventilation and dead space (left pair). At top are capnograms from breaths with reduced and normal tidal volumes, respectively Observe the box shape with plateau (phase III) of the normal capnogram on the right and the rounded shape of the abnormal capnogram on the left. End-tidal tensions of the normal capno8ram are greater than those of the abnormal capnogram.

The diagrams represent gas in the lung and in the Y-piece of a circle system. Of each pair the left shows inspiration, the right, expiration. Fresh gas (not shaded), deposited during inspiration, fills the anatomic dead space. Observe that the alveolar concentration of C02 is higher with increased dead space and reduced tidal volume.

A capillary taps into the gas column just outside the anatomic dead space and represents the site of collecting gas for capnometry. ]'he capillary points to the capnogram corresponding to the phase of ventilation. Observe that the site of collecting gas for capnometry sits on top of additional dead space due to a mask (left pair). For the right pair an endotracheal tube is depicted.

Because of the reduced tidal volume and the added dead space from the left pair, the high alveolar concentration of carbon dioxide never reaches the sampling capillary. The corresponding capno8ram, therefore, fails to reflect the fact that in this instance, alveolar (and, hence, arterial) C02 tension exceeds that of the right pair, even though end-tidal C02 tension is higher for the right pair than for the left pair.



Inspection of the capnogram, therefore, is essential during capnometry. Many older capnometers do not offer capno8rams for inspection; instead, they simply report the highest expired C02 tension in a digital readout. This explains why these so-called "end-tidal" tensions are quite different from arterial tensions at times.

Other disturbances can magnify the gradient between end-tidal and arterial PCO2 (see Gravenstein IS, Paulus DA, Hayes TI: Capnography in Clinical Practice, Stoneham, Massachusetts: Butterworths, 1989, available through the APSF office). However, in the pediatric patients described hem where improved ventilation and gas samp4ng corrected the problem, the simple mechanisms (increased anatomic dead space and shallow ventilation) are very likely the cause.

Is hypercarbia deleterious? In healthy patients the answer is a qualified no. As long as hypercarbia does not become excessive, increased arterial PCO2 is not dangerous. There are three concerns, though:

1. As the alveolar concentration Of C02 increases, the alveolar concentration Of 02 must decrease. On room air, hypoventilation leading to hypercarbia is hypoventilation leading to hypoxemia. However, an atmosphere enriched with oxygen can prevent the hypoxemia.

2. Hypercarbia may lead to increased sympathetic activity and, thus, set the stage for arrhythmias, for example during halothane anesthesia.

3. Hypercarbia raises brain blood flow. Any patient at risk of increased intracranial pressure should not be exposed to hypercarbia.

Is hypercarbia during routine induction of inhalational anesthesia in children avoidable? Probably, but perhaps not always. Premedication with inspiratory depressants, breath holding with induction of inhalation anesthesia, and respiratory depression with intravenous induction agents contribute to hypercarbia. Meticulous attention to the airway and assisted or controlled ventilation (as indicated) help maintain relative normocarbia. Once the endotracheal tube is in place, depressed ventilation can be corrected easily; at the same time, sampling of end-tidal gas for capnography becomes easier. Intubation dramatically reduces dead space, and tidal volume can be adjusted as desired based on the more correct end-tidal C02.

Dr. Gravenstein, in addition to co-authoring the book on capnography, is Graduate Research Professor of Anesthesiology at the University of Florida and a member of the APSF Executive Committee.

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Current Questions in Patient Safety: ET Tubes for Laser to Larynx?

Question: "What are the safest endotracheal tubes for use during ND-YAG and C02 laser treatment of the upper airway?"

Answer: This question, like many apparently simple questions, must receive a hedged answer with caveats. Although the American National Standards Institute has addressed this issue', its directives are rather general and some confusion exists now about choices.

The primary concern in using lasers in the aerodigestive tract is fire (6): not primarily of the tissues, which because of their water content provide a large heat sink and a relatively noncombustible substrate, but of the endotracheal tube. The localized fire caused by the laser beam striking combustible material may initiate a blowtorch-like combustion that can rage down the tracheal tube, sustained by the oxidizers oxygen and nitrous oxide, and devastate the respiratory tract with severe bums (5).

Efforts at preventing laser-induced combustion in the aerodigestive tract consist of:

1) Reducing the concentration of oxygen and nitrous oxide in the inspired gas and the ambient gas surrounding flammable materials (20)

2) Reducing the flammability of endotracheal tubes placed in the path of the laser (7,8,ll,l8)

3) Keeping energy levels and firing times as short as practicable.

Since lasers remove tissue by heating cellular water and thus bursting cells with the steam generated, combustion is not necessary for the beneficial effects of laser surgery. Tissue combustion (and consequent smoke) can be decreased by using concentrations of oxygen approaching that of room air, if such low concentrations are appropriate for the patient under anesthesia (frequently not the case). In addition, the use of helium instead of nitrous oxide as a dilutent increases the time required for ignition of some tracheal tubes by as much as 100% due to the increased thermal diffusivity of the gas mixture (18).

One approach to preventing ignition of the endotrachial tube by the laser is not have one in place when the laser is Firing. This can be accomplished by spontaneous ventilation with insulation, jet venturi ventilation via special attachments to the suspension laryngoscope (9,10,15,16,21,22)or by successive periods of hyperventilation with an endotracheal tube separated by apneic laser intervals with the tube removed.

Two basic types of endotracheal tubes for laser surgery are still acceptable for use (in spite of strong statements in the literature condemning one and praising the other): non-flammable metal tubes and tubes of potentially flammable materials that have been rendered resistant to ignition by some means. A variety of metal tubes have been proposed;2,12 with two exceptions 16, all are uncuffed. They have a relatively small internal/external diameter ratio, thus restricting their use in pediatric patients. 'mere is some degree of reflection of the laser off the tube to adjacent tissues, there may be heating of the tube with resultant thermal injury, and cleaning is problematic because of the crevices inherent in their spiral construction. Nevertheless, some institutions live with these problems, preferring the impossibility of ignition.

Several papers have discussed both ignition and flammability of endotracheal tubes (1) in atmospheres of varying concentrations of oxygen and/or nitrous oxide, (2) with varying power of the lasers, (3) with different wavelengths of lasers, and (4) with different combinations of tube materials and provide schemes. lotion, the tendency of a tube to begin to bum, is divided into two categories: external ignition, which occurs when sufficient thermal energy is transferred from the laser to the tube material, and internal ignition, which happens when the laser penetrates the tube material and combustion is supported by the respiratory gases. Flammability refers to the ability of the tube material to support combustion continuously once ignition has occurred. Ignitability and flammability of tube materials do not necessarily correlate with one another.

Tube materials vary considerably in their ignitiability and flammability, and research data are hard to compare without standardization of ambient atmosphere inside and outside the tube, laser type, power, pulse duration and repetitions, or maximum continuous application of the laser to the tube. Certain common factors emerge from the literature, however. Some authors have suggested that tubes made of polyvinyl chloride should not be used with lasers in the aerodigestive tract (11, 17, 18) because of their susceptibility to easy penetration by both C02 and Nd-YAG lasers and their subsequent internal ignition. Tubes of silicone tend to be resistant to lower laser energies, but when they do bum they leave silica ash in the respiratory tract, a fact of unknown significance (5,13,20). The, is a special-material "laser shield" tube. Although initial reports with lower power lasers were promising (8), it appears to fall apart with violent ignition and flammability at high laser energies, arguably higher than clinically likely (18). In the event of an incorrect power setting, however, the initial impulse might prove dangerous for the patient.

The red-rubber tube has the disadvantage of a high-pressure low-volume latex cuff, is relatively susceptible to ignition, but is resistant to continuous combustion (7,11,18,20). Aside from generating quantities of black smoke, the tube tends to hang together because the hole created by the laser tends not to extend, and a blowtorch-like flammability is not such a problem, particularly at lower 02 and N20 concentrations. Finally, these tubes can be protected dependably from ignition with reflective aluminum or copper tape (18)

Use of metallic tapes has a checkered past, since not all tapes are created equal. Earlier studies failed to show protection, but they used inferior tapes compared to those used in later studies. Sosis et al. (18) found the 3M #425 tape (3M Corp., Minneapolis, MN) offered the best protection against ND-YAG laser followed by I mm thick copper foil (Venture Tape Corp., Rockland, MA). These tapes were also protective against the C02 laser at high outputs. Other tapes tested offered varying degrees of protection or no protection. Controversy still exists about whether to wrap the tubes in a continuous spiral from cuff to connector or to use an overlap wrapping of a single larger piece laid longitudinally against the tube. In either case, the possibility of shredding, kinking, tissue damage including epistaxis and tape delamination with exposure to the laser must be considered. Also, reflections may contribute to unwanted tissue damage in non-diseased areas. In addition, protection of all printed areas, and the barium stripe, if present, from exposure to the laser helps minimize laser penetration due to energy absorption by the markings.

Tubes can be protected as far as they can be wrapped. They are vulnerable at the cuff and the distal unprotected tube tip. Protection of the tracheal tube cuff is problematic, since the wall is so thin, and a leak of respiratory gases caused by a ruptured cuff may accelerate ignition by an external hit of the laser on tube or tissues. Many use saline to inflate the cuff, since the water acts as a heat sink, and any holes caused by the laser immediately spray saline over the area, protecting against combustion. Deflating the cuff for extubation in case of a fire in the tube shaft may be much slower, however. Others use saline-soaked cotton pledgets or patties, whose strings, unless made of wire, are flammable, too. The pledgets may dry out and be ignited, also.

In summary, intelligent choice of an appropriate endotracheal tube for laser surgery involves planning: (1) Whether a tube needs to be present during Laser impulses; (2) A cuffed versus uncuffed tube; (3) Whether a metallic or nonmetallic tube will be used; (4) How a nonmetallic tube will be protected, both shaft and cuff; (5) What cumbustion-supporting gas concentrations will be necessary in the tube during laser therapy; and (6) Confirming that the wavelength of laser used really is safe for the tube planned (if the combination of tube and laser is new, it is prudent to conduct on-site tests before clinical use).

Answer by Reynolds J. Saunders, M.D., Staff Anesthesiologist and Co-Chairman, Quality Assurance Committee, Cedars -Sinai Medical Center, Los Angles.


1. American National Standards Institute Z 1 36.3 (1987): American national standard for the safe use of lasei3 in health care facilities.

2. Bradley IP. flexible metal endotracheal tubes for ENT laser surgery [letter] Anaesth Intensive Care 1987; 15:248-9.

3. Brightwell AP. A complication of the use of the laser in ENT surgery. J. Laryngol Otol 1983;97: 671-2.

4. Cohen SR; Herbert WI; Thompson JW. Anesthesia management of microlaryngeal laser surgery in children: apneic technique anesthesia. laryngoscope 1988;98:347-8.

5. Duncavage JA; Ossoff RH; Rouman WC; Toohill RJ; and others. Injuries to the bronchi and lungs caused by laser-ignited endotrached tube FIRES. Otolaryngol Head nECK Surg 1984;92: 639-43.

6. Fontenot R Jr; Bailey BI; Steinberg CM; Jenicek IA. Endotracheal tube safety during laser surgery. laryngoscope 1987;97:919-21.

7. Geffin B; Shapshay SM; Bellack GS; Hobin K; Selzer SE. Flammability of endotracheal tubes during ND-YAG laser application in the airway. Anesthesiology 1986;65:511-5.

8. Hayes DM; Gaba DM; Goode RL. Incendiary characteristics of a new Laser-resistant endotracheal tube. Otolaryngal Head Neck Surg 1986;95:37-40.

9. Herbert IT, Berlin J; Eberle R. let ventilation via a copper endotracheal tube for C02 laser surgery of the oropharynx. Laryngoscope 1985;95:1276-7.

10. Hunton 1; Oswal VH. Anaesthesia for carbon dioxide laser laryngeal surgery in infants. A new tracheal tube Anaesthesia 1988;43:394-6.

11. Kellman RM; Chilcoat RT. Incendiary characteristics of endotracheal tubes [letter] Ann Otol Rhinol Laryngol 1983;92:21 1.

12. Norton ML. Anesthesia for laser surgery in laryngobronchoesophagology. Otolaryngol Clin North Am 1983;16:785-91.

13. Ossoff RH; Duncavage IA; Eisenman TS; Karlan MS. Comparison of tracheal damage from laser-ignited endo-tracheal tube fires. Ann Otol Rhinol Laryngol 1983;92:333-6.

14. Pashayan AG; Gravenstein IS; Cassisi NJ; McLaughlin G. The helium protocol for laryngotracheal operations with C02 lasers retrospective review of 523 cases. Anesthesiology 1988;68:801-4.

15. Scheck PA; Mallios C; Knegt P; van der Schans El. High frequency ventilation in laser surgery of the larynx. Clin Otolaryngol 1984;9:203-7.

16. Silver CE; Schneider KL; Merav AD; Nagashima H. Prototype airway management system for use during laser surgery. Laryngoscope 1984;94:1511-2.

17. Sosis M. Polyvinylchloride endotracheal tubes are hazardous for C02 laser surgery [letter] Anesthesiology 1988;69:801-2.

18. Sosis M. Evaluation of five metallic tapes for protection of endotracheal tubes during C02 laser surgery. Anesth Analg 1989; 68:392-3.

19. Thode SA. Laryngo-tracheal laser surgery and general anesthesia. Lasers Surgery Mod 1986;6:369-72.

20. Waif GL; Simpson 11. Flammability of endotracheal tubes in oxygen and nitrous oxide enriched atmosphere Anesthesiology 1987;67:236-9.

2 1. Woo P; Strong MS. Venturi jet ventilation through the metal endo-tracheal tube: a nonflammable system. Ann Otol Rhinol Laryngol 1983;92:405-7.

22. Woo P; Vaughan CW. A safe, nonflammable, all metal, cuffless endotracheal Venturi ventilation system for use in laser surgery. Otolaryngol Head Neck Surgery 1983;91:497-501.

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Recommendations for Monitoring Standards in the U.K. and Ireland

by Professor Anthony P. Adams

The Association of Anaesthetists of Great Britain & Ireland (AAGOD published recommendations for Standards of Monitoring during Anaesthesia and Recovery in July, 1988. This was followed by a long debate in the fall at the Association's Linkman Meeting attended by delegates from all over the British Isles. This annual meeting acts as a forum for an exchange of views between member anesthesiologists and the Association's officers.

Strong support was expressed for the document. This will strengthen anesthesiologists' requests to senior hospital management for the provision of sufficient monitoring equipment to permit the concept of safe monitoring which has been termed by many a far more satisfactory term than minimal monitoring Anesthesiology has been grossly underfunded in the British Isles and insufficient resources are available to the specialty for provision of monitoring equipment. It is not generally recognized that the cost of M monitoring when calculated on a per patient basis can be really very low.

The Working Party which produced the document consisted of eight members of the AAGBI Council (including the President and the President-elect) under the Chairmanship of Professor Anthony P. Adams of Guy's Hospital. Professor Keith Sykes the Consultant Advisor to the Department of Health was also a member.

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Monitoring for All Phases of Care

The AAGBI document addresses the provision of standards of monitoring in the anesthetic room, the operating room, the recovery room, and during transfer of patients under the care of the anesthesiologist within the hospital and between hospitals. The concept of monitoring from before induction until after recovery from anesthesia is stressed. This has caused many anesthesiologists to reconsider the use of the traditional British anesthetic room as an induction room because of the need for reduplication of equipment and the problem of transferring patients into the operating room while maintaining full monitoring. Opinion is divided on this point but the anesthetic room can always be retained as the anesthesiologist's "base" for reception of patients, establishment of venous access and application of monitoring sensors. The document recognizes that standards for patient monitoring have been promulgated in several countries, notably at Harvard Medical School (1986) and at other institutions in the U.S.A., which lead on to adoption by the A.S.A. The Netherlands adopted standards as far back as 1978.

The increase in malpractice insurance premiums by 7 1 % in 1987 and by 88% in 1988 in the U.K., plus the publicity given by several legal cases has also focused attention on safety; further rises in premiums are due this year and there is a real prospect that differential subscriptions according to specialty will be introduced, something hitherto unknown in the U.K.

The AAGBI document emphasizes the need for the continuous presence of the anesthesiologist throughout the conduct of the anesthetic so the patient can be observed constantly and an adequate record kept; " also applies to any local or regional anesthetic or sedation involving a risk of unconsciousness, or cardiovascular or respiratory complications either from the technique employed or from systemic toxicity of the local anesthetic agent or sedative drugs.

The document also addresses the monitoring of the anesthetic machine and the monitoring of the patient as separate but intimately related functions. The emphasis is always on clinical observations first, with a back up constant supply of information coming in to the anesthesiologist's senses from monitoring instruments. The recommendations also apply to operations or procedures of brief duration including those outside the operating room (dental extraction or conservation, endoscopy, cardioversion, electroconvulsive therapy, etc). The use of routine pulse oximetry, and capnography with a tracing display of the C02 waveform, is strongly recommended.

Summary of Main Recommendations

(The full recommendations are not reproduced here for reasons of space but are available from the AAGBI at 9 Bedford Square, London WCIB 3RA, England.)

a. The anaesthetist should be present throughout the conduct of the whole anesthetic and should ensure that an adequate record of the procedure is made

b. Monitoring should be commenced before induction of anaesthesia and continued until the patient has recovered from the anesthetic.

c. Monitoring of anesthetic machine function should include an oxygen analyzer (with alarms) and devices which enable leaks, disconnections, rebreathing or overpressure of the breathing system to be detected.

d. Continuous monitoring of ventilation and circulation is essential. This may be performed using the human senses augmented, where appropriate, by the use of monitoring equipment. Clinical observations include the patient's color, responses to the surgical stimulus, movements of the chest wall and reservoir bag, palpation of the pulse and auscultation of the breath and heart sounds. Continuous monitoring devices include the pulse plethysmograph, the pulse oximeter, the electrocardiograph, the capnograph, and devices for measuring vascular pressures and body temperature

e Where intermittent non-invasive methods are used to measure arterial pressure and heart rate the frequency of measurement should be appropriate to the clinical state of the patient.

f. A peripheral nerve stimulator should be readily available when neuromuscular blocking drugs are employed.

g. Additional monitoring may be required for long or complicated operations and for patients with co-existing medical disease.

h. Adequate monitoring is needed during brief anesthetics or when using local anesthetic or sedation techniques which may lead to loss of consciousness or to cardiovascular or respiratory complications.

i. Appropriate monitoring should be used during transport of the patient whilst under the care of the anaesthetist.

j. Anaesthetists should issue clear instructions concerning monitoring during postoperative care when handing over the patient to recovery ward staff. Appropriate monitoring facilities should be available in the recovery ward.

The College of Anaesthetists held a Symposium of Safety and Standards of Anaesthesia in November last yen; one speaker, a prominent lawyer, thought the AAGBI recommendations were excellent and sorely needed the only problem he felt was that many words such as 'should' really ought to be ,must'. This was particularly interesting as many anesthesiologists are now of the same opinion. It must be admitted that the original document produced by the AAGBI working party was somewhat watered down before publication because some members of Council had strongly objected to too many words such as "must"! Indeed the word "appropriate" (in [e] and [i]) has met with justified criticism. However, from the outset, this document has been regarded as an important step in patient safety as well as to advise and support our members, and we anticipate that revisions will be required from time to time to take account of changes in clinical practice and the evolution of technology.

A very important point remains which is the training of anesthesiologists in the use of monitoring equipment. It is often amazing that many practitioners still do not know the default alarm settings of monitors or bother to set the alarm limits appropriate to the patient concerned.

Anthony P. Adams, M.B., B.S., Ph.D., FFARCS, FFARACS, is Chairman of Association of Anaesthetists of Great Britain & Ireland Working Party on Safe Monitoring, Chairman of AAGBI Safety Committee, and from the Department of Anaesthetics, United Medical & Dental Schools, Guy's Hospital, London, England.

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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 in March, June, September, and December at Overland Park, Kansas. Annual membership: Individual $25.00, Corporate $500.00. This and any additional contributions to the Foundation are tax deductible

The opinions expressed in this newsletter are not necessarily those of the Anesthesia Patient Safety Foundation or its members or board of directors.

APSF Executive Committee:

Ellison C. Pierce, Jr., M.D., President; W Dekle Rountree, Jr., Vice-President; E.S. Siker, M.D., Secretary; Burton A. Dole, Jr., Treasurer; Jeffrey B. Cooper, Ph.D.; Joachim S. Gavenstein, M.D.; James E Holzer, J.D.

Newsletter Editorial Board:

John H. Eichhorn, M.D., Stanley 1. Aukburg, M.D., Jeffrey M. Beutler, C.R.N.A., M.S., Ralph A. Epstein, M.D., David E. Lees, M.D., E.S. Siker, M.D., Benard V. Wetchler, M.D., Mr. Mark D. Wood

Address all general, membership, and subscription correspondence to:


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

John H. Eichhorn, M.D.

Editor, APSF Newsletter; Dept. Anesthesia Beth Israel Hospital, DA-717 Boston, MA 02215

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