Drug Administration Errors in Anesthesia: A Review

53 Pages·2004·0.6 MB·English

Drug Administration
Errors in Anesthesia:
A Review

D. John Doyle MD, PhD, FRCPC
Pema T. Tulotsang BSc

Revision 1.1

DRAFT NOTES
May 12, 2004

Refer to file drug review ww 8g2.doc for color
scheme for references and additional information
Department of General Anesthesiology
Cleveland Clinic Foundation
9500 Euclid Avenue E31
Cleveland, Ohio, USA 44195
Email [email protected]
Tel 216-444-1927
Fax 216-444-9247

KEYWORDS

Drug administration errors, error prevention, medical ergonomics, human factors in medicine,
risk management

53 Pages
1
Abstract

Drug administration errors have been an increasing focus of concern in
anesthesiology. These errors usually pertain to the type of drug administered, the drug
dosage, the rate of administration or the site of administration. Past studies have
attempted to identify and understand the underlying etiology of these common forms of
errors, so as to avert its often serious and sometimes fatal consequences. These
studies have focused on errors relating to the administrator's theoretical knowledge,
clinical experience, individual technique and other such related factors. This growing
body of research has proven invaluable, not only by addressing the preventability of
drug errors by clinicians, but also in leading constructive efforts to minimize their
repeated occurrence. This article attempts to highlight the current understanding of
drug administration error in clinical anesthesia and discusses the risk management
techniques that may be of value in dealing with this problem.

2
Introduction

Error is an inevitable aspect of all human endeavor, but in medicine, and
especially in the field of anesthesia, it can take on life or death consequences.1-3 The
overall rate of critical incidents in anesthesia is cited at less than 1% of all reported
cases. However, 50% to 80% of these preventable 'critical incidents' are due primarily
to human error, with nearly 7% resulting in otherwise avoidable, "substantive negative
outcomes".4

One of the most serious type of errors, comprising a significant subset of these
events, involves drug administration.5 Approximately 15% of all anesthetic critical
incidents involve drug administration errors, which can include administration of the
wrong drug, the wrong dosage, the wrong route, an incorrect speed of delivery or any
combination of these.5

Past reports analyzing various aspects of these drug incidents, including error
etiology and future prevention, have been published.4,5 Nevertheless, numerous
incidents of otherwise preventable drug errors continue to occur. This article attempts
to summarize the current understanding of drug errors in anesthesia as an aid to clinical
risk management.

3
Drug Administration Errors

'Error' has been defined as "a planned sequence of mental or physical activities
which fails to result in an intended outcome" 6. In this review, 'drug errors' in anesthesia
are addressed specifically in the context of the following four categories: wrong drug,
wrong route, drug overdose, and drug rate.

Wrong Drug
This is the most pervasive type of drug administration error, whereby a drug
other than the one intended is administered to the patient. In one survey, 30% of
anesthesiologists admitted to having made this type of error at least once in their
career.7 According to one report, wrong drug errors constituted approximately 60%8 of
all drug administration errors and in another study, these were responsible for nearly
8% of all reported anesthetic critical incidents.9

Anesthetics most frequently implicated in “wrong drug” errors were non-
depolarizing relaxants followed by opioids, succinylcholine (suxamethonium), and local
anesthetics. Table 1 lists the anesthetic drugs most commonly “intended” for
administration, while Table 2 lists those most often incorrectly “selected” instead.9

The primary source of wrong drug incidents are generally "syringe swaps" or
ampule errors, both of which refer to the accidental interchanging of the intended
container with another, resulting in the wrong drug being administered. Syringe swaps
4
occur more frequently than do ampule errors, and they are the underlying factor of at
least 46% of wrong drug incidents.9 By contrast, ampule errors constitute only 25% of
these cases.9 Table 3 lists some syringe and ampule errors in anesthesia.

In both instances, over half of the drug errors involved ampules or syringes of
similar size, label and/or color. This occurs despite the fact that, in nearly two-thirds of
the syringe swaps, the syringe or ampule was correctly labeled and, thus, readily
identifiable.9

Other contributing factors cited in wrong drug incidents include errors involving
drug location, labeling, assisting personnel and equipment use. In the study done by
the Australian Incident Monitoring Study (AIMS), 'fatigue' was a major factor in 10% of
reported wrong drug cases, while 'inattention' was cited nearly 50% of the time.
Fortunately, none of the 144 reported drug error incidents resulted in serious long-term
complication.9

Wrong Route
Critical incidents involving the administration of an anesthetic drug via an
incorrect route are sometimes a result of risks inherent to a particular procedure. For
example, the incidence rate of inadvertent dural puncture during epidural analgesia is
cited at one in 100 (although inversely proportional to experience of the
anesthesiologist).10 Alternately, migration of an epidural catheter into the subarachnoid
5
space may sometimes occur. In such cases, the drugs believed to be administered in
the epidural space may end up in the subarachnoid space.

A quite different situation exists when drugs normally given intravenously (IV) are
given via the wrong route. For example, Stedmon and Hammond11 documented a case
of midazolam and fentanyl being accidentally infused through the epidural route. In
1987, Chong and Davis reported a case of intra-arterial injection of propofol.12

In comparison, the number of documented cases involving an inappropriately
chosen route, using either an intended or unintended drug, is much fewer.

Drug Overdose

The administration of an unintended dose of drug is a relatively common error in
clinical anesthesia. These errors can include large doses of the intended drug or, in
some instances, be compounded by errors in drug selection.13 Such errors are
sometimes a direct result of arithmetic mistakes in dilution.

Confusion between preparations of varying concentrations commonly occur
despite the warnings and markings prominently displayed on drug labels and
packages.14 An example of such an incident was cited by Edgren and colleagues 15 in
1986. This incident involved a mix-up between a 5% dextrose solution with lidocaine
hydrochloride, which resulted in the IV delivery of 1200 mg of lidocaine over a one-hour
6
period. Although the patient was only 6-years old and fatal outcomes in adult patients
administered similar dosages have been previously documented, the child recovered
fully without sequelae.

However, in the Cooper et al. 4 study, which examined over 1000 preventable
critical incidents across 4 hospitals, approximately 20% of the cases classified as
'substantive negative outcomes' were associated with drug overdose.

Drug Rate
The speed of anesthetic injection can become a serious concern when it involves
drugs such as vancomycin or ritodrin, which dictate a specific rate of administration
(Table 4). This instant flooding of the circulation by toxic drug doses can produce
serious, if not fatal, consequences.

For instance, in 1983, Chalmers 16 reported the inadvertent administration of
etomidate at a rate of 250 mg over 45 minutes, rather than the prescribed 35 mg/hr, or a
tenfold increase in the intended rate. Patient death resulted within the following week,
succumbing to a deteriorating cardiac condition. This case is representative of other
incidents of incorrect rates of drug administration, usually resulting from misuse of
anesthetic devices. Other cases result from problems with drug labeling or other causes
17, 18, 19

7
Risk Management

Drug error usually remains undetected until the patient manifests unexpected
physiological reactions or, in fewer cases, fails to exhibit an expected result.9 Either of
these situations can signal to the anesthesiologist that a procedural error has occurred.
Ideally, this event will initiate a series of steps to successfully manage and resolve the
crisis.

Comprehensive procedural outlines governing anesthetic risk management are
an essential aspect to reducing drug error. As discussed in previous reports, once the
mistake has been recognized, action should be directed to reducing or reversing drug
toxicity to maximize patient safety. Fortunately, most drug errors are quickly detected
and successfully reversed.20

Second, an immediate investigation into the incident is necessary so as to
identify the primary source of drug error (e.g., ampule swap), thereby reducing the
likelihood of another similar occurrence.

Third, all drug error incidents, whether major or minor, should be reported to the
relevant parties. These parties may include hospital risk management officers as well
as various national agencies. Regretfully, there are strong incentives against such
reporting, particularly when anonymous reporting is not available.

8
International forums, such as the Critical Incident Reporting System (CIRS) in
Switzerland and the Australian Incident Monitoring Study (AIMS), both distribute and
collect critical incident reports. They guarantee a maximal degree of anonymity and
medico-legal safety, a situation that tends to elicit very honest and detailed accounts
from anesthesiologists. These reporting systems provide insight into contextual details
and contributing factors to critical incidents, thus guiding correcting strategies to curb
such future occurrences 9 INTERNET These reporting systems are universally applicable
and in fact, often draw parallels between common anesthesia-related errors across the
world. For example, the first 2000 reports collected from Australia and New Zealand in
the AIMS study shared some similarity with the pattern, nature and proportion of
incident reports found in the United States “closed-claims” studies. 9 INTERNET

In Canada, it is recommended that incidents associated with drug labeling be
directed to The Canadian Society of Hospital Pharmacists (CSHP), as well as the
Canadian Drug Manufacturers Association (CDMA). 21

In the United States, the Food and Drug Administration (FDA) oversees both
drug experience and drug quality reporting systems, which monitor adverse events
resulting from drug labeling, packaging and other related factors.

Specific factors often implicated include similarity between drug packages and
drug names. These reporting systems are invaluable not only in alerting manufacturers
9
and health care workers of error-prone situations, but also in implementing the
necessary changes to reduce their future occurrence. 22

Preventive Measures

Lack of experience was one of the most commonly cited factors in anesthesia
critical incidents, reflecting the need for greater and improved instructional training of
anesthetic administrators. This is most relevant to residents, whose "sudden
immersion" into the often stressful environment of the operating room (OR) may
possibly increase their susceptibility to error.4

For instance, a survey conducted by Cooper et al. 13 reported that over 50% of
the mistakes made by staff anesthesiologists during their careers had occurred while
they were residents. These figures suggest that closer supervision of residents and
stricter adherence to standard protocol could minimize these sources of error. Similarly,
past studies have consistently emphasized the need for "meticulous attention" during
anesthetic administration. 21

Another preventive strategy includes the standardization of drug arrangements in
the anesthesia workplace so as to avoid placing similar sized and shaped drug
ampules, syringes and other items close together on the anesthetic cart.23 Some even
researchers suggest changing suppliers, if need be, to obtain different labels and
reduce the likelihood of drug confusion. 21
10