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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
What, then, was the status of anesthesia patient
safety in 1954? From a somewhat humorous standpoint it was well
described in the preface of Stanley Sykes' wonderful essays, "The
First Hundred Years of Anesthesia". (6) He quotes Lincoln,
in his Gettysburg Address, "It is for us, the living, rather
to be dedicated here to the unfinished work which they who fought
here have thus so nobly advanced. It is rather for us to be here
dedicated to the great task remaining before us, that...we here
highly resolve that these dead shall not have died in vain".
But an enormous awakening was also at hand in 1954. It began with
the huge controversy that greeted the publication of the paper by
Beecher and Todd, "A Study of the Deaths Associated with Anesthesia
and Surgery", which appeared in the July 1954 issue of Annals
of Surgery in my first month as an anesthesia resident. (7) I remember
the anger in Dr. Dripps' voice as he refuted the data, especially
the statement that the study "strongly suggests an inherent
toxicity" in the neuromuscular blocking drugs. The publication
was one of the first to add a denominator when considering anesthesia
deaths; evaluations of the previous 100 years were limited to analyses
that did not consider the number of anesthetics administered. Beecher
examined nearly 600,000 anesthetics administered over a five year
period in ten university hospitals. He noted who the anesthetists
were, what techniques and agents were used, and whether the trachea
was intubated. The incidence of anesthesia mortality was found to
be 3.7 per 10,000 anesthetics with anesthesia as a primary cause.
One year later, also in Annals of Surgery, sixteen distinguished
American anesthesiologists published a paper entitled, "Critique
of 'A Study of the Deaths Associated with Anesthesia and Surgery'".(8)
They stated, (we) "believe that many of the important conclusions
drawn by Beecher and Todd are not justified on the basis of the
statistics presented..." and suggested that missing data in
the Beecher paper, such as site of operation, depth of relaxation
required, duration of anesthesia and operation, and severity of
surgical trauma, negated many of the conclusions. They, as had Dripps
and Manny Papper at Columbia, objected strongly to the suggestion
that use of "curare" results in higher mortality rates.
A few years later, in a retrospective study initiated after the
Beecher paper, Dripps analyzed the role of anesthesia in surgical
mortality at the University of Pennsylvania. (9) Among some 33,000
patients given either a general anesthetic to which neuromuscular
blockers were added or a spinal anesthetic there were no deaths
attributable to anesthesia in ASA Physical Status I patients, although
the overall mortality rate with anesthesia as the primary cause
was 11.7 per 10,000 anesthetics.
Here, then, were two decades of numerous studies world wide of
anesthesia deaths, with mortality rates ranging from 1 to 12 per
10,000 anesthetics. Anesthesia study commissions, examining postoperative
deaths, proliferated. A well known one was in Baltimore, directed
by Otto Phillips, where during a five and a half year period ending
in 1959 they found anesthesia to be the principal cause of mortality
in some 6% of the deaths and a contributing factor in 13%.(10) Phillips
declared death from anesthesia a major public health problem. He
opened a review of anesthesia mortality with an anonymous quotation;
"You members of the medical profession, gentlemen, are in a
favored position - the world acclaims your successes and flowers
cover your failures." (11)
Perhaps the most important result in all of this was the increased
interest among anesthetists in improving anesthesia outcomes. It
was in 1962 that I became interested in anesthesia patient safety.
I had joined Leroy Vandam at the Peter Bent Brigham Hospital as
defacto Vice Chairman. In his inimitable way one day he assigned
me the subject, "anesthesia accidents", to be given as
a resident's lecture. I still have notes in my files from that talk,
which began a collection of anesthesia mishaps that I knew about
personally, somewhat akin to a chapter in Sykes' Essays, entitled,
"37 Little Things Which Have All Caused Death". (12)
Arthur Keats, who had been an anesthesia resident at the Massachusetts
General Hospital during the period that the Beecher study was undertaken,
criticized anesthesia mortality studies. He argued in 1970 that,
"the relative risk of all anesthetics commonly used today remains
unknown". (13) He stated that, " for most deaths, assignment
of the relative roles of anesthesia, surgery and patient disease
is based on retrospective assumptions, hindsight judgement, bias,
and incomplete information." He opened his paper with a quotation
from Sir William Osler, "Errors in judgement must occur in
the practice of an art which consists largely in balancing probabilities."
Later Dr. Keats continued his thesis, in the 1978 Crawford W. Long
Memorial Lecture at Emory (14), and the 1990 Seldine Lecture.(15)
He re-emphasized that we in anesthesia are unable even to define
an anesthetic death. Bias often exempts anesthetic agents from adequate
risk/benefit analysis. He particularly criticized the classic 1948
article, "Deaths Under Anesthetics", by the eminent British
anesthetist, Robert Macintosh, who stated, that all anesthetic deaths
are preventable, the result of errors. (16) Dr. Keats wrote, "Thirty
years of self flagellation in the form of anesthetic mortality studies
have generated an abundance of 'errors'...,all published estimates
of the incidence of error the incidence of anesthetic deaths are
now unacceptable...Demonstration of a cause-effect relationship
is absolutely essential if any secure knowledge of mechanisms of
anesthetic deaths is to be achieved." He cited the discovery
of new mechanisms for anesthesia death such as malignant hyperthermia
and succinylcholine induced hyperkalemia. Dr. Keats concluded that
we must rid ourselves of error bias.
William Hamilton , Keats' great friend and hunting companion of
many years, in an editorial, challenged the implication that drugs
per se are responsible for an important number of anesthetic deaths.
(17) He did agree that much bias had been present in anesthesia
mortality evaluations, especially equating departure from current
clinical practices with error. In contrast, Dr. Hamilton believed
that anesthesiologists had carefully evaluated risk/benefit concepts
following review of death reports, as in halothane hepatitis, for
example. He stated that whereas we previously tended to blame drugs
or the patient's disease when anesthesia went amiss, now we correctly
recognize the ever increasing importance of human error; --- "To
blame an undiscovered or unexplained acute toxic effect of a drug,
an idiosyncratic reaction, or divine intervention, as would appear
to be Dr. Keats' thrust, is very questionable when we know that
physician errors can result in mortality." He stated that the
controversy between Keats and him concerned the relative role of
drugs as problems in opposition to management errors on the part
of the anesthetist and concluded that "... it is important
to know whether anesthetic deaths attributable to error amount to
10 or 90 per cent". "In my view error is near the 90%
end." I have reviewed the debate between Keats and Hamilton
because it remains relevant. Moreover, I also believe the scale
is closer to the 90% end.
The almost exclusive use of crude anesthesia mortality studies
to evaluate anesthesia outcome was brilliantly interrupted in 1978
with the publication of Jeffrey Cooper's first paper describing
critical incident analysis applied to anesthesia. (18) The technique,
utilized in military aviation during World War II, had a profound
effect on aviation safety which continues even today.
Cooper simply discarded evaluation of mortality rates as the major
measure of negative anesthesia outcome. Rather, he stated, "Factors
associated with anesthetists and/or factors that may have predisposed
anesthetists to err have, with a few exceptions, not been previously
analyzed. Furthermore, no study has focused on the process of error
- its causes, the circumstances that surround it, or its association
with specific procedures, devices, etc. - regardless of final outcome."
Data for this first study using the critical incident technique
in anesthesia were obtained from 47 interviews of staff and resident
anesthesiologists at a large teaching hospital. In a follow up paper
published in 1984 the database was enlarged to include a total of
139 anesthesiologists, residents, and nurse anesthetists from four
Boston hospitals in which 1,089 descriptions of preventable critical
incidents were collected. (19) Their 1978 tables listing the distribution
of frequent critical incidents and associated factors are now classics
(Tables 1 and 2).
- Train, Educate, and Supervise
- Use appropriate monitoring instrumentation and vigilance.
- Recognize the limitations influencing individual performance.
- Establish and follow preparation and inspection protocol.
- Assure equipment performance.
- Design and organize work space.
- Act on incident reports - eliminate the pitfalls.Based upon his
observations, Cooper early on proposed corrective strategies to
lessen the likelihood of an incident occurring. (20)
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