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June 1996
Volume 60 |
Number 6
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| Closed Malpractice
Claims for Awareness During Anesthesia |
Karen B. Domino, M.D.
"I remember feeling the cold plastic tube being inserted
down the back of my throat. I remember trying to cough, talk,
open my eyes and do anything to signal that I was still awake.
At that point, I began to panic, and I could feel my heart racing.
I was crying inside, but no one noticed my tears. The sensation
and memory were similar to what I have read about people being
buried alive."1
As is vividly described here, awareness under general anesthesia
is a terrifying experience. However, by virtue of its nonphysical
nature, awareness is not as easily recognizable or quantifiable
as are other anesthesia-related injuries. While it is often assumed
that the emotional sequelae of awareness are transient in nature,
permanent disability due to recurrent nightmares, sleep disturbances,
impaired social interactions, difficulties at work and post-traumatic
stress disorder may occur.
The true incidence of intraoperative awareness and recall is poorly
documented but varies according to the type and depth of the anesthetic
technique. High rates of recall have been reported in major trauma
(11 percent to 43 percent)2 and obstetric anesthesia
(2.5 percent to 4 percent).3 The overall incidence
of awareness (0.2 percent for all general anesthesia cases)4
has decreased during the past 10 years, coincident with
increased perception of the problem by anesthesiologists.5
At the same time, patient concern with the possibility of intraoperative
awareness has also increased, with up to 50 percent of patients
expressing anxiety over intraoperative awareness.6
The patient profile for malpractice claims for intraoperative
awareness and whether the rate of claims is changing are unknown.
We therefore examined closed claims maintained by the ASA Closed
Claims Project database. The database contains a standardized
collection of case summaries of adverse anesthesia-related outcomes,
obtained from 35 insurance carriers throughout the United States.
The data represents closed malpractice claims and does not provide
overall incidence statistics for intraoperative awareness.
Closed Claims Analysis
Out of 3,533 claims in the ASA Closed Claims Project database, there were 69
claims for awareness (2 percent), including 54 claims for patient
recall of events under general anesthesia (1.5 percent) and 15
claims for inadvertent paralysis of awake patients (0.4 percent).
The rate of claims for awareness and awake paralysis was similar
to rates of claims for myocardial infarction, aspiration pneumonia,
back pain and hepatic dysfunction following anesthesia [see Figure
1]. These rates suggest that intraoperative awareness is a
significant source of lawsuits against anesthesiologists. Although
the public's and anesthesiologists' concerns about awareness have
increased, the proportion of awareness claims has remained relatively
stable during the years of the ASA Closed Claims Project.
The rate of payment for awareness claims was the same as for other
claims (57 percent). However, the severity of injury in awareness
claims (temporary, minor, etc.) was usually lower than the severity
of other claims in the database (generally permanent and disability).
Awareness claims resulted in a lower payment than other anesthesia
malpractice claims, with a median payment of $18,000 for recall
during general anesthesia, compared to a median payment of $100,000
for nonawareness claims [see Table
1]. However, substantial sums of money were recorded in awareness
claims, with highest payments awarded for awareness complicated
by other anesthetic complications (e.g., $600,000 for a case complicated
by aspiration pneumonitis) or severe permanent disability (e.g.,
$125,000 for post-traumatic stress disorder).
Awake Paralysis
Most cases of awake paralysis were related to intravenous infusion
errors or syringe swaps. Infusion errors included the use of nonlabeled
succinylcholine bags (two cases), mislabeled succinylcholine bags
(two cases) and failure to check the label on unintended succinylcholine
drips (six cases), accounting for two-thirds of the claims for
awake paralysis. Syringe swaps occurred with properly labeled
drugs in three cases and mislabeled syringes in two cases. Reviewers
considered most cases of awake paralysis to be examples of substandard
anesthesia care, even though the paralysis was promptly recognized
and appropriately managed.
Recall During General Anesthesia
In contrast to the awake paralysis claims, most of which were
secondary to vigilance errors, recall under general anesthesia
had a variety of etiologies. The anesthetic care was classified
as substandard in 42 percent of cases, which is similar to classification
for all other claims in the database but less than the percentage
for awake paralysis claims (substandard in 93 percent of cases).
In substandard cases, recall occurred as a result of failure to
turn on a halogenated agent vaporizer, vaporizer malfunction or
failure to administer appropriate amounts of anesthetic agents
during induction; however, recall often occurred in the presence
of an anesthetic that met the standard of care such as with use
of amnestic agents or during a period of hemodynamic instability.
Hypertension and tachycardia were occasionally clinical cues for
awareness, although these signs were absent in most cases.
In order to determine risk factors for claims for recall during
general anesthesia compared to other types of malpractice closed
claims, 52 recall claims and 2,072 other general anesthesia claims,
which had sufficient detail concerning anesthetic agents, were
compared using logistic regression analysis. Five factors were
significantly associated with recall under general anesthesia
claims: female gender, gynecological/obstetrical procedures, use
of opioids, use of muscle relaxants and lack of use of a volatile
anesthetic agent [see Table
2].
Female gender tripled the risk of an awareness claim, compared
with other general anesthesia malpractice claims. Gynecological/obstetrical
procedures and anesthetic techniques involving use of muscle relaxants
and/or opioids doubled the risk of malpractice claims for recall.
In contrast, use of a volatile anesthetic agent reduced the risk
of recall claims by one half. After adjusting for the other risk
factors using multiple logistic regression analysis, female gender,
gynecological/obstetrical procedures and anesthetic techniques
involving muscle relaxants remained as independent risk factors
for malpractice claims for recall during general anesthesia.
The increased risk of recall claims arising from anesthetic techniques
that use opioids, use muscle relaxants and do not use volatile
anesthetics is logical and predict-able. Likewise, an association
of recall with gynecological/obstetrical procedures is not surprising
because of the common use of light anesthetic techniques during
these procedures.
Unfortunately, the number of recall claims in the database was
too small to allow a more detailed examination of risk with different
surgical procedures. The increased propensity for women to file
suit for recall during general anesthesia is somewhat surprising.
In general, women are not more likely than men to sue for minor
adverse outcomes, according to the ASA Closed Claims Project.
However, women may be more likely than men to sue for emotional
injury.
Conclusion
Recall during general anesthesia or awake paralysis is a frightening
experience, which may lead to serious emotional injury. The ASA
Closed Claims Project analysis of awareness claims suggests that
deficiencies of labeling and vigilance are common etiologies for
awake paralysis. Claims for recall during general anesthesia represent
a more diverse group. Risk factors for claims for recall under
general anesthesia include female gender, gynecological/obstetrical
procedures and anesthetic techniques using muscle relaxants and
opioids without volatile anesthetic agents.
References:
1. Personal communication with a patient who experienced intraoperative
awareness.
2. Bogetz MS, Katz JA. Recall of surgery for major trauma. Anesthesiology.
1984; 61:6-9.
3. Crawford JS. Awareness during operative obstetrics under general
anesthesia. Br J Anaesth. 1971; 43:179-182.
4. Liu WHD, Thorp TAS, Graham SG, et al. Incidence of awareness
with recall during general anesthesia. Anaesthesia. 1991;
46:435-437.
5. Ghoneim MM, Block RI. Learning and consciousness during general
anesthesia. Anesthesiology. 1992; 76:279-305.
6. McCleane GJ, Cooper R. The nature of preoperative anxiety.
Anaesthesia. 1990; 45:153-155.
Karen B. Domino, M.D., is Associate Professor
of Anesthesiology at the University of Washington School of Medicine,
Seattle, Washington.
Send e-mail to Dr. Domino
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