Volume 2, No. 1, pp 1-8
March, 1987
Table of Contents

ASA Adopts Basic Monitoring Standards
Safety Foundation Needs Members
Outpatient Anesthesia: No Double Standard
Anesthesia Machine Standards Enhance Safety
From the Literature
Technical Topics
Foreign correspondence
Drager Equipment Safety Book Available Free
Ohmeda book Available Free

ASA Adopts Basic Monitoring Standards

by John H. Eichhorn, M.D.

With precedent-setting resolve the American Society of Anesthesiologists' House of Delegates at the ASA annual meeting in October adopted formal standards of practice for intra-operative monitoring. "Standards for Basic Intra-Operative Monitoring" (see page 3) represents the first set of detailed specifications of the minute-to-minute conduct of anesthesia practice published by the ASA.

The ASA Ad Hoc Committee on Standards of Care reported ". . . this should have a major impact in reducing unexpected deaths related to anesthesia due to human error. The judgment of the anesthesiologist in assessing the patient's condition has been acknowledged and preserved as an integral part of the success of any venture which is directed at improving patient safety and optimizing cam We believe that the Standards combine the art of medicine with the reasonable application of technology."

Requirements Outlined

The standards mandate the presence of qualified anesthesia personnel in the room throughout all anesthetics and the continual evaluation of the patients' oxygenation, ventilation, circulation, and temperature. Monitoring of end-tidal C02 (capnography) for ventilation and use of pulse oximetry for oxygenation are cited as quantitative evaluations (rather than the traditional qualitative methods) and are "encouraged".

The standards are practical and realistic, as shown by the notation of the possibility of brief interruptions and various exceptions. There is elaboration of the methodology to be employed to help ensure adequate oxygen availability, ventilation, circulatory function, and maintenance of temperature. Provisions are made for future revision of the standards, as warranted by the evolution of technology and practice.

In the process of developing the standards, the ASA Committee on Standards of Care focused on the potential preventability of anesthesia morbidity and mortality. The committee reviewed the literature and also case files from the Harvard associated malpractice insurer, the State of Washington, and the ASA dosed claims study This review led to the conclusion that improved intraoperative monitoring could make the greatest impact and should be the first area of attention.

Burton S. Epstein, M.D., chairman of the committee, suggests that the development of these monitoring standards and other standards to be proposed in the future should "significantly improve" the chances of a successful outcome of an anesthetic. He noted that the standards constitute an ASA attempt to clearly delineate methods by which anesthesia accidents due to human error can be reduced.

The ASA committee debated whether to include capnography and pulse oximetry as the "standard of care' 'At that time, it was felt impractical to mandate very specific (and very expensive) high tech equipment when the greatest focus of the effort was the general extension of the vigilance of the anesthesiologist. The committee also considered the questions of the consistency of performance of these two instruments and the availability at that time relative to the potential demand. However, E. C. ("Jeep7') Pierce, M.D., committee member and past president of the ASA, now states, "Capnography and oximetry are becoming so widespread that they will he functional standards. Projecting current trends, it is likely that by the end of 1988, enough oximeters will have been sold for there to be one available for every operating room in the country".

Dr. Eichhorn, Harvard Medical School, is a member of the ASA Committee on Standards of Cam and Editor, APSF News Letter.

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Safety Foundation Needs Members

To our readers:

While we mail more than 50,000 copies of this newsletter to those interested in anesthesia patient safety we only have about 3,000 individual memberships in the Anesthesia Patient Safety Foundation (APSF).

The Foundation is supported financially solely by memberships and contributions from individuals, corporations and foundations. As you can see from the adjacent APSF distribution of expense chart for 1986, nearly 70 percent of our income went towards research awards for studies on the prevention of anesthesia mishaps. It was disappointing, however, that we were only able to fund four of the many meritorious grant applications because of a lack of money.

Therefore we hope that you find enough value alone in the information contained in our four-times-a-year newsletter to become an individual or corporate member of APSF. Individual memberships are $25 and corporation memberships begin at $500. Several companies have given $25,000 and we have a generous grant from the Parker B. Francis Foundation.

We need your support to carry on our important efforts for the safe use of anesthesia and hope you will become an APSF member by making your tax deductible check payable to the Anesthesia Patient Safety Foundation and enclose it in the envelope attached between pages six and seven of this newsletter.

Your financial support makes it possible for the Foundation to continue its work. We thank you.

The Board of Directors

Anesthesia Patient Safety Foundation


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Outpatient Anesthesia: No Double Standard

by Bernard V. Wetchler, M.D.

As we in anesthesia are being removed from the safety of our traditional operating room cocoon, we should not change our obligation to our patients and to ourselves. Whenever we provide anesthesia services, the equipment, the staff and the facility must meet currently acceptable standards of cam There can be no double standards of anesthesia care.

In the area of ambulatory surgery, anesthesia practitioners have to be like cat burglars--getting our patients in and out without touching any of the alarms. When managing the outpatient, we should never allow ourselves to become so enamored of new surgical procedures, new anesthetic agents, or the ambiance of the facility that we forget the basics: selection of appropriate patients and appropriate procedures. The anesthesiologist is the watchdog of ambulatory surgery and as such, must take an active role in the necessarily compacted perianesthetic management of the outpatient.

It is our task to educate the surgeon and the surgeon's office staff, the initial contacts for the patient, as to what is considered an acceptable patient and an acceptable ambulatory procedure in 1987. So-called healthy patients for so-called short surgical procedures should undergo a thorough history and physical examination by the surgeon and a complete screening questionnaire

In addition to what takes place at the surgeon's office, every facility should develop its own method of preoperative screening. This can be accomplished by the patient visiting the facility several days before the scheduled procedure or this screening ran take place by way of telephone interview. Preoperative screening gives us necessary information about the patient, provides the patient with instructions, and can determine Laboratory tests that should be ordered. Also discovered are the necessity of consultation with other physicians, how far in advance the patient should be evaluated by an anesthesiologist, and the need for additional psychological support. Effective screening will not only help limit last minute cancellations but may affect patient safety and morbidity.

Initially, the majority of ambulatory facilities accepted only ASA physical status I and 11 patients. As we have be-come more experienced and selection criteria have become increasingly more liberal, we find that we are now accepting more physical status III patients. For any physical status III patient, the medical condition that classified them as a III must be in stable and good condition before that patient can he considered acceptable for an ambulatory procedure.

Patient age per se should not be a limiting factor. Each patient must be considered individually. High risk infants, however, are best handled in an inpatient setting. The infant with a low hemoglobin or hematocrit is at risk. The infant presenting with a history of respiratory distress syndrome, prematurity, apnea or aspiration with feeding is also at risk. It is generally accepted that the ex-premature should not be operated on as an outpatient until they are at least 46 weeks post conceptual age (gestational age plus postnatal age). The ex-premature less than 46 weeks post conceptual age must be apnea monitored for 24 hours post operatively as an inpatient. Al the 1985 ASA meeting, Children's Hospital of Philadelphia presented a study which established their post conceptual age of acceptability for the outpatient ex-premature as greater than 60 weeks. At the 24th Clinical Conference in Pediatric Anesthesiology, Frederick Berry, M.D. stated "infants under 50-55 weeks post conceptual age need to be carefully monitored for the development of apnea after surgery even if they have had an apnea-free interval before surgery." Children's Hospital National Medical Center (Washington, DC) prospectively studied the incidence of post anesthetic apnea and periodic breathing in infants less than twelve months postnatal age undergoing general anesthesia for hernioorrhaphy. They concluded it is probably best to delay nonessential surgery for preterm infants until they are beyond 44 weeks post conceptual age. Although there appears to be no universal agreement as to what constitutes an acceptable post conceptual age for the outpatient ex-premature, there is agreement that caution must be exercised before the ex-premature is considered acceptable for any ambulatory surgical procedure.

At the opposite end of the age scale, we find the geriatric patient. Patients with multiple medical problems and on multiple medications must be carefully evaluated before being accepted as candidates for ambulatory surgery. This is dependent upon: physiologic age, physical status, surgical procedure, proposed type of anesthesia, and quality of home cam Physical status, surgical procedure and anesthetic technique must be addressed individually and collectively before the anesthesiologist accepts or rejects the geriatric outpatient. Chronologic age should be neither a consideration nor a deterrent.

Every outpatient other than those having local anesthesia, must have a responsible person take them home and monitor their needs after surgery and anesthesia. A responsible person is defined as someone who is physically and intellectually capable of taking care of the patient at home. If the person does not meet this criterion, the facility has an obligation to make other arrangements for the patient.

With the rapid changes taking place in ambulatory surgical care, lists of acceptable procedures or specific sets of characteristics rapidly become obsolete. We must be particularly cautious of the laundry lists provided by government, industry, and third party payers. The intents of these lists is to let us know that reimbursement for a particular procedure will be either limited or nonexistent unless the procedure is performed on an ambulatory basis. Third party lists must never substitute for sound, flexible, and progressive medical judgment. Neither the patient nor the

procedure can be viewed separately from the other when determining acceptability for ambulatory surgery.

Frederick Orkin, M.D. has stated, "the actual list of acceptable procedures in a given ambulatory unit is established in an evolutionary process" with the medical director on a daily basis deciding which procedures are acceptable for the facility, "Given its equipment, its staff and their capabilities, the ability and reliability of the given surgeon, and the medical condition of the particular patient."

Although the risks to the patient associated with so-caged minor surgery are generally less than those associated with so-called major surgery, the risks relating to anesthesia remain relatively constant. At the Federated Ambulatory Surgery Association Meeting in Boston last April, mortality statistics reported from 135 of FASA's member facilities revealed 17 deaths in approximately 1. I million procedures. If we, as anesthesiologists, don't start thinking of standards of care for the outpatient, someone else is going to do it for us, and in their minds, with good reason.

In 1986 we were performing 30% of all surgeries in the United States on an outpatient basis; by 1990 it is projected that number will approach or exceed 50% of all surgeries. Although there are similarities in the manner in which anesthesiologists manage their inpatients and outpatients, the differences are sufficient that we should take an active role in developing standards of anesthesia care and methods of assessing quality of care that are specific for the outpatient. With quality of care having to be balanced against cost effectiveness, each outpatient center must develop its own quality assessment program to assure that selection decisions as well as other aspects of care, provide the patient with a safe ambulatory surgical experience. On a regular basis, data should be reviewed to determine if morbidity or unexpected hospitalization is due to a particular procedure, a particular physician, a particular patient population, or to a particular type of anesthesia.

Quality assessment studies will allow us to modify decisions on patient, procedure, and anesthesia selection based on our own experiences. The basic mission of quality assessment is to achieve improvement in both the quality of care provided and patient safety.

Dr. Wetchler of Medthodist Medical Center of Illinois, Peoria, is President of the Society for Ambulatory Anesthesia and a member of the Newsletter Editorial Board.

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(Approved by House of Delegates on October 21, 1986)

These standards apply to all anesthesia care although, in emergency circumstances, appropriate fife support measures take precedence. These standards may be exceeded at any time based on the judgment of the responsible anesthesiologist. They are intended to encourage high quality patient cam but observing them cannot guarantee any specific patient outcome. They are subject to revision from time to time, as warranted by the evolution of technology and practice. This set of standards addresses only the issue of basic intra-operative monitoring which is one component of anesthesia cam In certain mm or unusual circumstances,

1) some of these methods of monitoring may be clinically impractical, and

2) appropriate use of the described monitoring methods may fad to detect untoward clinical developments. Brief interruptions of continual monitoring may be unavoidable under extenuating circumstances, the responsible anesthesiologist tiny waive the requirements marked with an asterisk (*), it is recommended that when this is done, it should be so stated (including the reasons) in a note in the patient's medical record. These standards are not intended for application to the care of the obstetrical patient in labor or in the conduct of pain management.

Note the "continual" is defined as "repeated regularly and frequently in steady succession" whereas "continuous" means "prolonged without any interruption at any time"


Qualified anesthesia personnel shag be present in the room throughout the conduct of all general anesthetics, regional anesthetics and monitored anesthesia care.


Because of the rapid changes in patient status during anesthesia, qualified anesthesia personnel shad be continuously present to monitor the patient and provide anesthesia cam In the event there is a direct known hazard, e.g., radiation, to the anesthesia personnel which might require intermittent remote observation of the patient, some provision for monitoring the patient must be made. In the event that an emergency requires the temporary absence of the person primarily responsible for the anesthetic, the best judgment of the anesthesiologist will be exercised in comparing the emergency with the anesthetized patient's condition and in the selection of the person left responsible for the anesthetic during the temporary absence.


During all anesthetics, the patient's oxygenation, ventilation, circulation and temperature shall be continually evaluated.


To ensure adequate oxygen concentration in the inspired gas and the blood during all anesthetics. METHODS

1) Inspired gas: During every administration of general anesthesia using an anesthesia machine, the concentration of oxygen in the patient breathing system shall be measured by an oxygen analyzer with a low oxygen concentration limit alarm in use.

2) Blood oxygenation: During all anesthetics, adequate illumination and exposure of the patient is necessary to assess color. While this and other qualitative clinical signs may be adequate, there are quantitative methods, such as pulse oximetry, which are encouraged.


To ensure adequate ventilation of the patient during all anesthetics.


1) Every patient receiving general anesthesia shall have the adequacy of ventilation continually evaluated. While qualitative clinical signs such as chest excursion, observation of the reservoir breathing bag and auscultation of breath sounds may be adequate quantitative monitoring of the C02 content and/or volume of expired gas is encouraged.

2) When an endotracheal tube is inserted, its correct positioning in the trachea must be verified. Clinical assessment is essential and end-tidal C02 analysis, in use from the time of endotrachial tube placement, is encouraged.

3) When ventilation is controlled by a mechanical ventilator, there shall be in continuous use a device that is capable of detecting disconnection of components of the breathing system. The device must give an audible signal when its alarm threshold is exceeded.

4) During regional anesthesia and monitored anesthesia cam the adequacy of ventilation shall be evaluated, at least, by continual observation of qualitative clinical signs.


To ensure the adequacy of the patient's circulatory function during all anesthetics.


1) Every patient receiving anesthesia shag have the electrocardiograrn continuously displayed from the beginning of anesthesia until preparing to leave the anesthetizing location.

2) Every patient receiving anesthesia shag have arterial blood pressure and heart rate determined and evaluated at least every five minutes.

3) Every patient receiving general anesthesia shall ham in addition to the above, circulatory function continually evaluated by at least one of the following; palpation of a pulse, auscultation of heart sounds, monitoring of a tracing of intra-arterial pressure ultrasound peripheral pulse monitoring, or pulse plethysmography or oximetry.


To aid in the maintenance of appropriate body temperature during all anesthetics.


Them shall be readily available a means to continuously monitor the patient's temperature When changes in body temperature are intended, anticipated or suspended, the temperature shag be measured.

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Anesthesia Machine Standards Enhance Safety

by Kay Plantes, Ph.D. and Anne Berssenbrugge, Ph.D. (Part two of two parts)

Part one of this article described ten technological advancements in anesthesia machine design which have significantly improved patient safety Yet, many of the machines currently in use do not contain these safety features which have been developed primarily within the past ten years.

Of necessity, capital spending limitations have led to a situation in which the equipment inventories of many hospitals are comprised of anesthesia machines which vary vastly in age; some are new, some may be more than twenty years old. Thus, an important ingredient in managing anesthesia safety is for clinicians to understand the capabilities, limitations and operation of each anesthesia machine they use.

Knowing when to replace older units and how to assess the adequacy of safety features available on currently marketed units also plays a role in managing anesthesia safety. To this end, it is valuable to understand the design and manufacturing standards that apply to anesthesia machines and the extent of their role in promoting equipment safety. This article addresses two of the most common questions asked of anesthesia systems manufacturers about standards: "Do our hospital's anesthesia machines meet standards?" and "Do the machines you sell meet standards?"

While the intent of each question is straightforward-users wish to ensure that equipment complies with safety criteria established by external authorities-the answer is considerably more involved.

The anesthesia community is, in fact, affected by a variety of "standards". These include standards of patient care defined by institutions, professional societies, and insurance companies; standards for hospital and departmental certification (ICAH); implied standards of care used in the courts to decide the outcome of medico4egal cases; and rules which govern the design, performance and manufacture of medical products.

Manufacturing procedures of anesthesia equipment manufacturers are governed by legally mandated regulations that a company must follow under the threat of being brought to court or shut down. In addition, product design standards for safety and performance exist, but they are not now part of the regulatory structure. However, they may be either mandatory or voluntary.

The major regulations which govern anesthesia equipment manufacturers are those defined by the U.S. Food and Drug Administration (FDA). It was not until 1976 that the FDA further defined and extended its authority in regulating medical devices, with the passage of the Medical Device Amendments to the Food, Drug and Cosmetic Act, and its promulgations through administrative rules.

The primary FDA laws and resulting regulations which govern the activities of anesthesia equipment manufacturers include:

1. Medical Device Amendments, 1976: Regulates product labeling, manufacturer registration and new product introduction procedures.

2. Good Manufacturing Practices, 1978: Regulates medical device manufacturing, distribution and quality assurance procedures, including procedures a manufacturer must follow for product recall.

3. Mandatory Device Reporting, 1984: Governs how and when manufacturers report alleged serious malfunctions of their equipment and injuries and deaths occurring while their medical device was in use.

While the FDA has the authority under the 1976 Medical Device Amendments to regulate the performance and safety characteristics of anesthesia capital equipment (i.e., specific features which a medical device must contain), it has not, to date, exercised this authority. For example, the FDA does not require an anesthesia machine to be designed to preclude delivery of hypoxic mixtures to the fresh gas outlet. Recently, however, the FDA published notification in the Federal Register of its intent to issue regulations on standards of performance for some medical devices. In deciding which specific medical devices deserve its limited resources for producing regulatory standards, the FDA evaluates whether appropriate voluntary standards exist for a given medical device. Anesthesia machines and monitors have not been listed among the products to be initially addressed.

While the design of anesthesia equipment is not currently regulated by the federal government, it is measured against a broad array of voluntary standards. These standards are written by various technical, industrial, national, and international organizations composed of professional experts from the medical and manufacturing communities. The standards are based on a consensus of opinion and/or the result of extensive testing. Some state, county, and city governments reference standards as mandatory for the equipment purchased by hospitals within their jurisdiction. Thus, the standard functions like a law for any manufacturer wishing to sell equipment in these locations.

The major voluntary standards that affect the design of anesthesia capital equipment manufactured in the U.S. include:

1. International Organization for Standardization ISO 5358-198a International standards for continuous flow inhalational anesthetic apparatus.

2. American National Standards Institute Z79.81 979U.S. standards of minimum performance and safety for continuous-flow anesthesia machines for human use

3. Underwriters Laboratory, Inc. 544 1976: U.S. Standard for saw: medical and dental equipment. 4. Compressed Gas Association, Inc. VI 1 9 77. U. S. standards for compressed gas cylinder valve outlet and inlet connections.

Many of these standards are undergoing major revision. The ANSI standard for anesthesia machines, for example, is currently being rewritten by a subcommittee of the American Society for Testing and Materials (ASTM). As clinicians, manufacturers, insurance officials and hospital administrators work to improve anesthesia safety through the activities of the Patient Safety Foundation, it is interesting to reflect on the importance of regulations and standards. Are they a good vehicle for ensuring that anesthesia equipment meets a desired minimum safety level?

If an anesthesia system is designed and manufactured to conform with both regulations and standards, it should provide the user with the minimum level of safety and performance dictated by those criteria. However, because standards are voluntary, the user should not assume that all manufacturers' equipment complies. Furthermore, it is important to note that standards can be slow to change and may not keep pace with the development of new technology. Equipment that does meet design standards may not offer the most up to date safety features available.

Standards and regulations that relate to industry are one part of enhancing anesthesia safety, but by themselves they will not ensure that the current level of anesthesia patient safety is maintained or improved upon. The current drive within the anesthesia community to both establish other standards, specifically those related to patient care such as the minimum monitoring requirements at Harvard, and to increase the extent and quality of ongoing clinical education offer a greater opportunity to continue to improve anesthesia safety. As these efforts continue, the role of anesthesia equipment manufacturers will be to participate in and support clinical education and to continue to develop and incorporate new safety features into the design of the anesthesia system. Anesthesia systems now and in the future are and will be designed to minimize equipment-related mishaps and to effectively manage monitoring information in a manner which promotes added vigilance over both the machine and the patient.

Kay Plantes, Ph.D. is North American Marketing Manager and Anne Berssenbrugge, Ph.D. is Product Manager, Anesthesia Systems, Ohmeda, Madison, M.

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From the Literature

Editor's note: In each APSF Newsletter, a pertinent publication from the anesthesia patient safety literature will be summarized. Suggestions for future issues are welcome.

Eichhorn IH, Cooper IB, Cullen DI, Maier WR, Philip JH, Seeman RG. Standards for patient monitoring during anesthesia at Harvard Medical School. JAMA 2%:1017-1020,1986.

Many questions have been raised about the preventability of major anesthesia accidents. Such questions by Harvard's malpractice self-insurance entity led a risk management committee in the Harvard Department of Anesthesia (nine departments including academic, specialty, and community hospitals) to examine past claims and incidents. This study suggested that more meticulous monitoring of anesthetized patients would significantly help prevent such anesthesia accidents.

Basic monitoring practices were thought by the committee to be so important as to be mandatory, not simply suggestions or guidelines. Therefore, the concept of creating "standards of practice' was adopted so that each hospital would require its members to institute a minimum level of monitoring for every patient anesthetized. Because of the desirable S" of accident prevention and apparently sufficient communication with the practitioners who would have to live with them, the standards for monitoring were developed and then accepted with minimal dissension.

The standards specify constant presence of an anesthetist during an nesthetic, blood pressure and heart rate measurement at least every five minutes, and continuous display of an EKG tracing. Most importantly, continuous monitoring of ventilation and circulation each by one or more listed methods is the core of the program. Also required are a breathing system disconnect monitor during mechanical ventilation, an oxygen analyzer on every anesthesia machine, and the ready availability of a means to measure the patient's temperature The various caveats throughout the set of standards indicates that thought about unusual or extenuating circumstances was incorporated. These preserve the emphasis but make the standards realistic in day-to-day practice.

The response of most of those practicing anesthesia hopefully will be that they have been doing all these things for years. Nonetheless, nationwide insurance data (including preliminary reports from the American Society of Anesthesiologists' dosed claim study) show absence of even such basic monitoring in many accident cases. Guaranteeing minimal monitoring during anesthesia may yield improved overall outcome by decreasing preventable mishaps, which appear to represent a significant fraction of anesthesia-related morbidity and mortality.

Epidural analgesia (as distinct from anesthesia) for labor and pain management is excluded from the standards for alleged practical reasons. Even in the absence of equivalent data on risks in these settings, it seems logical and consistent with the thrust of the paper that some type of minimal monitoring should be mandatory here also.

The authors correctly note that physicians are individuals long accustomed to defining their own destiny and unaccustomed to having others tell them what to do. However, societal forces trying to control health care costs and assure the outcome of care threaten external imposition of potentially unpalatable authority. The Harvard monitoring standards are an example of a creative response generated from within the profession which may inspire others. The American Society of Anesthesiologists recently adopted national monitoring standards (see page 1) covering many of the same points in a different format. However, Eichhom et al. urge replication of the process rather than the standards themselves. There remain multiple other issues in anesthesia that could benefit from attention by such committees within many institutions and groups.

Abstracted by Thomas E Hombein, M.D., Chairman, Department of Anesthesia, University of Washington, Seattle

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Technical Topics

Danger in an Unpopped Valve

Rare is the anesthesiologist who has not encountered problems with the adjustable pressure limiting (APL) valve commonly known as the popoff valve on the anesthesia machine. Instead of allowing variable adjustments to the positive pressure attained within the patient breathing circuit and alteration of the gas volume contained within the rebreathing bag, the malfunctioning valve can offer only fully closed or a fully open position. This can lead either to barotrauma or inadequate ventilation.

This problem recently arose in the APL valve of an Ohio Modulus I machine that was serviced regularly under a preventive maintenance program from the manufacturer. On disassembly of the APL, the problem was readily apparent. Soda lime dust blown back from the absorber into the APL had escaped around the diaphragm seat and entered the adjustable mechanism via a small hole in the spring sleeve. This mixture of dust and moisture eventually caked and hardened, preventing the free movement of the pin inside the spring sleeve. The accompanying photograph shows the effect of this caking inside the APL valve housing. (Readers are referred to either the manufacturer's manual or The Anesthesia Machine: Essentials for Understanding by Bowie and Huffinan, Ohmeda, Madison, Wisconsin for a schematic representation.)

When this problem occurs, it is easily connected. The valve needs to be disassembled and inspected. The individual components need to be cleaned and rinsed of all deposits and reassembled. To check for a proper functioning APL valve, the assembly should rattle when shaken, indicating free movement of the pin within the spring and sleeve. Needless to say, once the cleansed APL has been reattached to the anesthesia machine, a full machine check-out should be performed. Often contract maintenance pro8rarns do not examine or disassemble the APL, but this should be added to the quarterly or biannual inspection routine.

Topic prepared by: Alvaro R. De LA Rocha, M.D., Instructor, New York Medical College; Attending Physician, Lincoln Hospital, Bronx, N.Y. Edited by David E. Lm, M.D.

DUST encrusted interior of an adjustable pressure limiting (pop-off) valve showing how soda lime dust can foul the mechanism and created a potential problem.

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Foreign correspondence

Comment from the Antipodes

by Dr. J.M. Gibbes

Dept. of Anesthesia, Christchurch Hospital,

Christchurch, New Zealand.

An item syndicated in newspapers throughout New Zealand on December 15, 1986 stated "Most anesthesia deaths fault of doctors" and went on to quote from an address by Professor Ronald Katz to a meeting of the New York State Society of Anesthesiologist. That this item was reproduced in New Zealand indicates the rising interest by the public in standards of medical practice.

Our medico-legal environment is greatly different to that in the United States. Firstly, lawyers are not paid on the basis of a portion of a court awarded settlement. Secondly, and of more importance, there is no right of an individual to sue a medical practitioner for civil negligence. The government owned Accident Compensation Corporation administers a compulsory insurance scheme under which any accident (including medical misadventure) is automatically the subject of compensation according to a specific set of rules without examination of fault or apportioning of blame.

A Different System

This is not the place to argue the virtues or otherwise of such a system but a perhaps predictable consequence has been a major increase in the number of patients bringing actions against doctors through other channels. The commonest has been a complaint of unprofessional conduct made to the Medical Council of New Zealand (as the statutory body responsible for standards of practice) or to the disciplinary committee of the New Zealand Medical Association. Anesthetists have been the subjects of a number of these complaints. Thus, we have the situation where anesthetists are having to examine their standards of practice without major financial pressures but because of public demand as well as the increased questioning of medical actions which is evident in so many countries.

Anesthetic practice in New Zealand has been historically developed from the British system. It has thus always been entirely physician based. There has been traditional emphasis on the need for clinical skills and observation and (at least until recent years) less on information from external measuring devices. It is only now that there is majority acceptance of the need for a continuous display of circulatory and ventilatory status throughout every general anesthetic. The recent statement of monitoring standards from the Harvard Medical School' has come at a most opportune time so far as this country is concerned.

We now have specialist anesthetists who have trained in Australia and in North America as well as in Britain. They have increased awareness in the anesthetic community of the ways in which clinical observation can be extended by the use of appropriate monitoring. EKG and peripheral pulse plethysmography is common place. The values of measurement of neuromuscular blockage have become apparent even to those of us who trained in Britain a number of years ago. In major surgical units and some hospitals you will see work done in the same way and to the same high standards as in comparable North American units.

Nevertheless, those of us who are responsible (as heads of departments) for provision of good facilities and modem equipment have major difficulties given the limited budgets available in the State funded Hospitals system. For example, in my own Department we have 28 anaesthetizing locations. A pulse oximeter costs approximately NZSIO,000. Our equipment grant for the 1986-1987 year totaled NZ$30,000. We thus have the dilemma of knowing what is available and what is clearly desirable to enhance patient safety but no way to provide it in the short term. We must carefully note the standards of care as these develop in other parts of the world but cannot necessarily accept them as immediately essential to anesthetic practice here. It is for these reasons that the basic common sense approach of the Harvard statement will be of enormous value to anesthetists in New Zealand.

New Zealand anesthesia owes much to the Faculty of Anesthetists, Royal Australian College of Surgeons (Australia and New Zealand work as a single unit in terms of training and accreditation of specialist anesthetists) for their insistence on high standards of training and of staffing in teaching hospitals. As well, we owe much to Dr. Ross Holland from Sydney, Australia for his work in the examination of anesthesia associated modality. Using criteria based on those of his committee, we have examined anesthesia associated mortality on a national basis during the last eight years. Our findings are at least similar to those reported by other committees although we have perhaps concentrated on individual feedback to reporting clinicians to a greater extent that is apparent in other reports. Of the cases reported to us, 34% included management problems for which the anesthetist could be held mponsible2. This is not "the majority of cases" referred to in the media quotation at the start of this column but perhaps the data base was different in Professor Katz's study.

Certainly, there is no reason for complacency in this country. Having been associated with our mortality assessment committee since its inception, I am of the view that the critical incident approach pioneered by the Boston group and in Australia by Dr. John Williamson 3 has more potential to improve standards of patient care if incorporated in the activities of a Department of Anesthesia. For one thing, there are more incidents than anesthesia associated deaths. Fortunately, studies can be done on a low cost basis and so, in contrast to equipment, are not influenced by the political whims of Government. These incidents can be examined at local, national or even international level and I hope that we in New Zealand could be part of some major studies. We have much to learn from each other.


1. Eichhom JH, Cooper JB, Cullen DJ, Maier WR, Philip JH and Seeman RG. Standards for Patient Monitoring during Anesthesia at Harvard Medical School. JAMA 1986; 256: 1017-1020.

2. Gibbs JM. The Anesthetic Mortality Assessment Committee 1979-1984. NZ Med j 1986; 99: 55-59.

3. Williamson IA, Webb RK and PW SL. Anesthesia safety and the "critical incident" technique. Aust. Clin Rev 1985; 57-61.

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Drager Equipment Safety Book Available Free

The SAFETY GUIDELINES FOR ANESTHESIA EQUIPMENT are aimed towards improving the safe use of anesthesia equipment. They are not a substitute for an operator's manual or instruction manual and, additionally, they do not cover all of the numerous safety aspects of anesthesia equipment. Examples of potential hazards are provided.

It is the objective of this booklet to discuss possible hazards related to anesthesia equipment and to recommend means for preventing accidents. It is one of the basic considerations in this respect that anesthesia systems and their components are man-made and, therefore, subject to possible malfunction. It is, further, understood that the operation of the equipment may be subject to human error by the operator.

Anesthesia equipment 1 5 years ago may have contained fewer than IO controls and possibly the same number of indicators. Anesthesia systems today could contain between 50 and 100 different controls, up to 50 displays and indicators, and more than 20 different alarm functions. This extremely complex system is comparable to the instrumentation of the flight deck of an aircraft.

The major causes for patient injury are categorized in the text of the booklet as follows:

* Insufficient oxygen supply to the brain

* Insufficient carbon dioxide removal

* Excessive anesthetic concentration

* Trauma to the lungs caused by excessive pressure

* Foreign matter injuring the airway

It is thought that the discussion and analysis of the scenario leading to hazardous situations will increase operator awareness and thus decrease the number of critical incidents.

The monitoring of equipment performance, patient condition and operator action as a means to reveal a hazardous situation has been widely recognized. Special consideration has therefore been given to the performance and performance limitations of the various monitors utilized with anesthesia equipment. The evaluation of the safety potential of the various monitors is summarized in a matrix where monitor performance is correlated with the causes for patient injury.

The very fact that critical incidents are rare will often find an operator unprepared for action when an alarm message is annunciation. An operator action in response to an alarm menage must be prompt and organized. The period of time between alarm annunciation and beginning of patient injury must be utilized to identify the source of the problem, to correct the problem and to reestablish normal and safe conditions. Organized action of the operator is essential to performing this task in the limited time available. A final section of the booklet is therefore devoted to recommending certain sequences of action after an alarm message has been generated.

Safety Guidelines for Anesthesia Equipment is available on a complimentary basis from your local North American Drager distributor or from North American Drager directly: (North American Drager, 148 B Quarry Road, Telford, PA 18969, Attn: Literature Dept.).

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Ohmeda book Available Free

The Anesthesia Machine: Essentials for Understanding fills an important role in the process of learning the safe use of anesthesia equipment by providing, in a concise and easy to read format, the underlying principles of the pneumatics and mechanics of how gases and mixtures are delivered to the patient as part of the administration of anesthesia. The user must know how the essential components operate in unison in order to be able to identify machine problem, correct or prevent them, and have the confidence to make decisions and alterations in the shortest amount of time.

The Anesthesia Machine: Essentials for Understanding, by Ed Bowie and Linda Huffman is especially recommended for new residents and is an excellent refresher book for practicing anesthesiologists and CRNAS.

Readers can write to Ohmeda, Ohmeda Drive, P.O. Box 7550, Madison, WI 53707, Attention: Linda Huffman, to request a free copy.

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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 Me Rountree, It., Vice-President; E.S. Siker, M.D., Secretary; Burton A. Dole, Jr., Treasurer; Jeffrey & Cooper, Ph.D.; Joachim S. Gavenstein, M.D.; James F. Holzer, J.D.

Newsletter Editorial Board:

John H. Eichhom, M.D., Stanley 1. Aukburg, M.D., Jeffrey M. Beutler, C.R.N.A., M.S., Ralph A. 4)stein, M.D., David E. Lees, M.D., E.S. Siker, M.D., Bernard V. Wetchler, M.D., Mr. Mark D. Wood

Address general correspondence to:


Anesthesia Patient Safety Foundation

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Park ridge IL 60068

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

John H. Eichhorn, M.D. Editor,

APSF Newsletter Anesthesia,

DA-717 Beth Israel Hospital

Boston, MA 02 2 1 5