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Ellison C. Pierce, Jr., M.D.,
Associate Clinical Professor of Anaesthesia, Harvard Medical School,
Chairman Emeritus, Department of Anaesthesia, Deaconess Hospital,
Boston, MA
On Thursday, April 22, 1982, there appeared on
ABC television a segment of the program 20/20 entitled, "The
Deep Sleep, 6,000 will die or suffer brain damage." (21) The
announcer opened the program, "If you are going to go into
anesthesia, you are going on a long trip and you should not do it,
if you can avoid it in any way. General anesthesia is safe most
of the time, but there are dangers from human error, carelessness
and a critical shortage of anesthesiologists. This year, 6,000 patients
will die or suffer brain damage." Following scenes of patients
who had anesthesia mishaps, the program went on to say, "the
people you have just seen are tragic victims of a danger they never
knew existed - mistakes in administering anesthesia." In another
example shown on the program a patient was left in coma following
the anesthesiologist's error in turning off oxygen rather than nitrous
oxide at the end of an anesthetic. Later in the program, the following
dialog ensues. An unidentified spokesperson advises Tom Jerriel,
one of the hosts, that, "there is a hospital in New York City
where there are two anesthesia people covering five operating rooms."
Jerriel is incredulous, and asks, "How do they do it?"
The spokesperson replies, "Well, they run quickly and pray
a lot."
The 20/20 program was a watershed for anesthesia patient safety
endeavors. At the time I was ASA First Vice President and decided
to establish a new ASA committee, the Committee on Patient Safety
and Risk Management. Howard Zauder was the first Chairman. ASA had,
of course, been involved in quality assurance for some time with
its Committee on Peer Review, but never before had the concept of
patient safety been so specifically addressed by our specialty society.
Among its first endeavors the Committee developed a series of patient
safety videotapes, still being produced, with me as Executive Producer.
The 25th tape, Perioperative Nerve Injury, just completed by Producer
Robert Stoelting, is being shown at the Patient Safety Booth. It
will be distributed to all United States anesthesia departments
by Glaxo Wellcome.
In 1984, Cooper, Richard Kitz, and I hosted the first International
Symposium on Preventable Anesthesia Mortality and Morbidity (ISPAMM),
held in Boston. Some 50 anesthesiologists from the United States,
Australia, Great Britain, South Africa, and Belgium attended. Debate
was loud and strong; controversy among the nations was extensive,
especially considering use of monitoring equipment. Perhaps the
area of greatest agreement was in the definitions of outcome, morbidity
and mortality (Table 3). That international meeting has now been
held every two years since.
The Anesthesia Patient Safety Foundation (APSF) was established
as an outcome of the Boston meeting. Considerations of attaching
a safety society to other entities, such as the World Health Organization,
were rapidly abandoned because of the probabilities that international
controversy would prevent effective actions.
To foster investigations that will provide a better understanding
of preventable anesthetic injuries.
To encourage programs that will reduce the number of anesthetic
injuries.
To promote national and international communication of information
and ideas about the causes and prevention of anesthetic injuries.The
Foundation has sought expert advice from a broad range of professionals
outside the ASA -- lawyers, pharmaceutical and device manufacturers,
risk managers, nurse anesthetists, insurers, and representatives
from the Food and Drug Administration, the Joint Commission, the
American College of Surgeons, and the American Medical Association
--- an undertaking certainly not possible in the structured environment
of the ASA at that time. The goals remain the same:
The quarterly Newsletter, with an estimated circulation of 60,500,
is in its tenth year, with John Eichhorn as Editor. APSF has awarded
34 research grants in patient safety, totaling $1,325,000.
What of more recent mortality studies? Major reports have come
from the United Kingdom where John Lunn and associates established
a confidential, anonymous system to report anesthesia deaths associated
with surgery. Their initial report was published in 1982. (22) Anesthesia
was considered partly or totally causative of mortality in one to
two cases per 10,000, and to be totally causative in nearly 1 per
10,000. Of significance was their determination that large numbers
of patients were not seen preoperatively by an anesthetist, did
not have blood pressure recorded intraoperatively, did not have
the machine checked by the anesthetist before beginning anesthesia,
and did not have intraoperative monitoring with EKG. The next report
in the continuing evaluation was the first edition of the Confidential
Enquiry into Perioperative Deaths (CEPOD), arranged by both the
Association of Anaesthetists and the Association of Surgeons of
Great Britain and Ireland. (23) It examined perioperative deaths
occurring during a twelve month period in three national health
service regions. In that period death attributable to anesthesia
alone was only 0.05 per 10,000 anesthetics, a figure far lower than
the earlier citation. The reviewers decided that 40% of the time
the anesthetic was less than ideal. Some 10% of fatal operations
were judged to have been unnecessary or unjustified.
Another continuing analysis of anesthesia mortality spanning nearly
the entire forty years of this lecture series is that from New South
Wales, Australia. (24) The overall death rate in which factors under
the control of the anesthetist caused or contributed to the fatal
outcome was thought to be about two per 10,000 operations in 1960,
one per 10,000 in 1970, and 0.5 per 10,000 in 1990.
In the United States it is not possible to approach examination
of anesthesia mortality in the way we have just discussed because
of our medical liability climate and nearly ineffectual coroner
systems. The important 1985 report by Keenan on cardiac arrest due
to anesthesia at the Medical College of Virginia studied, over a
15 year period, 160,000 anesthetics in which there were 27 cardiac
arrests, an incidence of 1.7 per 10,000 anesthetics. (25) He discovered
that the risk for emergency surgery was higher than that for elective,
as it was also for pediatric patients versus adult. Failure to provide
adequate ventilation was responsible for half of the cardiac arrests.
In 1991 Keenan provided a follow-up, in which he added data from
additional years and then divided the total into two decades. (Table
4). (26) Is this improvement in anesthesia risk? Absolutely!
Why the improvement? It should be noted that the second decade
began five years before capnography and pulse oximetry came into
common use. One identifiable occurrence in that period was the publication
of Cooper's first analysis of critical incidents. Keenan suggested
three general explanations for the improvement in outcome: first,
use of specific initiatives to detect and prevent hypoxic ventilatory
mishaps; second, significant increases in the number and quality
of anesthesia trainees; and third, use of better anesthesia techniques.
The ASA Closed Claim study, truly a major American effort to examine
anesthesia risk, also arose out of the 1984 Boston International
Meeting at which Richard Ward, then Professor of Anesthesiology
at the University of Washington, discussed his preliminary findings,
examining closed malpractice claims against anesthesiologists in
the state of Washington. They were published in a 1984 book, Analysis
of Anesthesia Mishaps, edited by Cooper and me. (27) Clearly the
twin malpractice problems, unavailability of medical liability insurance
in the 70's and the crisis of affordability in the 80's, suggested
the need to examine closed claims on a national basis. I remember
working with Ward on revisions to the data collection forms and
suggesting that the national project be given to the ASA Committee
on Professional Liability, which President Ketcham Morrell did in
1985. Fred Cheney, the Committee Chairman, then as well as now,
has noted, "The relationship of patient safety to malpractice
insurance premiums was easy to predict. If patients were not injured,
they would not sue, and if the payout for anesthesia-related patient
injury could be reduced, then insurance rates should follow."
(28) In the beginning it looked as if it would be difficult to get
insurance companies to turn over their closed claims data to outside
physicians. However, Mark Wood of the Risk Management Services at
St. Paul Fire and Marine Insurance Company was actually looking
for someone to review the Company's claims. Wood was also an attendee
at the Boston international meeting and was appointed an original
member of the APSF Board. Robert Caplan, then also at the University
of Washington, joined the Committee to help in the analysis. It
was decided that findings should be published in major, peer reviewed
journals. Fortunately, early on, local anesthesiologists were able
to convince the Massachusetts Joint Underwriting Association, the
Doctor's Company of Southern California and the New Jersey Medical
Underwriters to provide data.
The most important information coming out of the Closed Claim Study
is contained in the analysis of adverse respiratory events. (29)
With the earliest looks, these events constituted the single largest
class of injury, some 35% of the total. The first three mechanisms
of injury accounted for about three quarters of the total adverse
respiratory events; inadequate ventilation 38%, esophageal intubation
18%, and difficult intubation 17%. The majority of respiratory claims
were lodged before widespread adoption of pulse oximetry and capnography.
Reliance on indirect indicators of ventilation was often unsatisfactory
particularly in claims involving esophageal intubation. Death or
permanent brain damage occurred in 85% of the respiratory related
claims, contrasted with only 30% of the remaining (non-respiratory)
claims. Not surprisingly, this makes adverse respiratory events
particularly costly. The reviewers determined that better monitoring
would have prevented adverse outcomes in three quarters of the respiratory
claims, compared with only around 10% in the non-respiratory cases.
Both Cheney and Caplan believe that the advent of pulse oximetry
and capnography has been associated with the almost complete disappearance
of claims for the first two categories - inadequate ventilation
and unrecognized esophageal intubation (personal communication).
Following the realization that difficult intubation, the third category,
could largely not be prevented by better monitoring, the ASA turned
its attention to developing protocols, algorithms, lectures, and
videotapes to further knowledge about management of the difficult
airway. (30) The Closed Claims Project is now tracking the impact
of guidelines on professional liability.
Mark and her associates have vigorously promoted dissemination
of critical information concerning the difficult airway. (31) They
are to be commended for helping establish the Medic Alert Foundation
"Difficult Airway/Intubation" category. Besides use of
the ASA difficult airway algorithm they recommend entry of patient
data into hospital registries, use of a difficult airway/intubation
patient wristband, and distribution of summary reports to healthcare
providers.
There has always been a question about the percentage of human
error resulting from the design of anesthesia equipment. Leslie
Rendall-Baker has been a longstanding and relentless leader in this
area of inquiry, particularly as it relates to the anesthesia machine
and drug ampules. (32) (33)
Both major US anesthesia machine suppliers have expended great
effort to apply the latest knowledge of human factors engineering
either to prevent the possibility of a human error or to prevent
injury to the patient when human errors do occur. Means to prevent
human error include keyed filling devices for vaporizers to prevent
filling of vaporizers with the wrong agent, the diameter index safety
system for gas supply hoses, and the vaporizer interlock system
which prevents the simultaneous administration of two or more agents
at the same time.
Fill ports at vaporizers are located so that liquid spills over
before the vaporizer is overfilled. The O2 and N2O flow control
means are interlocked in such a way that the N2O flow is automatically
reduced in the event that the O2 flow is erroneously reduced to
a hazardous concentration. Twenty years ago, approximately 50% of
vaporizers increased the delivered concentration by a clockwise
rotation of the handwheel, while the other 50% increased the concentration
by a counterclockwise rotation. Manufacturers agreed to standardize
the vaporizer control to one direction. The most important contribution
to safety in the operation of anesthesia equipment, however, is
the incorporation and acceptance of monitors for O2, CO2, anesthetic
agents, disconnects and excessive pressure, as well as other ventilatory
parameters, into the anesthesia machine.
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