drug administration errors in anesthesia: a review
TRANSCRIPT
Drug Administration Errors in Anesthesia:
A Review
D. John Doyle MD, PhD, FRCPC
Pema T. Tulotsang BSc
Revision 1.1 DRAFT NOTES Refer to file drug review ww 8g2.doc for color scheme for references and additional information
May 12, 2004
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
Ideally, analysis within individual anesthesia departments must be undertaken to
properly identify frequently implicated sources of anesthetic errors in that environment.
Only then can effective safety measures be implemented to minimize drug error
incidents.
These and other preventive strategies were recommended and discussed in the
"wrong drug" study conducted by the Australia Incident Monitoring Study (AIMS).9
Although most outcomes involving drug errors are uneventful, those few cases of
otherwise avoidable long-term complications, or even death, clearly stress the
importance of drug error reduction. One such incident involves the epidural injection of
15 ml of 15% potassium chloride, when the latter was mistaken for 'distilled water' and
used as a diluent for bupivacaine. The patient's physiological reaction was immediate
and severe, resulting in permanent paraplegia and then death six months later. 24
Drug Labeling
The issue of drug labeling has been a source of continuous contention in
anesthesiology. Currently in North America, there is no single standardized system for
the distinctive labeling of anesthetic drugs. Only basic packaging and identification
guidelines exist which, in Canada, are set by the Canadian Society of Hospital
Pharmacists,21 while other agencies, such as The Health Protection Branch (HPB),
regulate the manufacturing and marketing of these drugs.25
11
Similarly, the FDA and its subsidiary, the Center for Drug Evaluation and
Research (CDER) is responsible for the regulation requirements and final approval of
drug labels in the United States. 26 However, the FDA is currently leading an
international project that aims to harmonize drug approval standards across
borders.27INTERNET
The increased focus on improving basic drug regulatory standards have left
many practitioners to call for a global drug identification system, that could facilitate the
ease and consistency of drug recognition. 28,29 For example, the color coding of
anesthetic agents into broad categories, such as induction agents, tranquilizers, muscle
relaxants, etc., would not only aid in proper drug recognition, but also provide greater
opportunities to identify improper drug selections made prior to administration.7
This last point is most pertinent to wrong drug incidents, where there is an 81%
probability that an incorrect drug will be administered, once accidentally selected by the
anesthesiologist.9 More precisely, when an ampule is inappropriately selected, the
likelihood of administering it is only 58%, but in the case of a syringe, the probability
jumps to 93%.9
Thus, the concerns expressed over similarity of drug labels is a valid one, a
situation that could greatly profit from the availability of these secondary cues.
12
This point is demonstrated in one ”wrong drug” incident involving the interchange
of similarly labeled ointments of lidocaine (5%), and nitroglycerin (2%), both of which
were manufactured by the same pharmaceutical company. The department involved
had commonly used lidocaine as a lubricant for endotracheal tubes and would have
overlooked the drug error if not for the peculiar color of the applied ointment. This
situation prompted a rechecking of the drug label and thus prevented yet another
anesthetic “mishap”.30
The value of a drug color-coding system becomes increasingly apparent, as
more anesthesiologists admit to relying on ampule appearance to distinguish drugs. As
one editorial summarized, "when such a number of different ampules are available,
primary selection of the one required is often by the overall appearance of the ampule,
its size and shape, color, style of lettering, length of wording etc. - all taken in at a
glance by a sort of mental shorthand developed from frequent use."7 This above
statement is clearly reflected in the fact that at least half of all ampule and syringe errors
in 'wrong drug' incidents are primarily description errors (Table 5).6
Apart from color-coding, some recent recommendations to improve drug labeling
have included painting the ampule tips red for drugs which are exceptionally dangerous
if administered at an incorrect rate.7 Others suggest that pharmaceutical companies that
also supply to other countries print only the generic names on drug labels, as common
names can vary across borders and lead to drug errors. 31 With the emergence of
13
similarly spelled drugs, suggestions such as capitalizing the initial dissimilar syllables to
enhance recognition have been proposed (Table 6).28
The lack of progress toward standardizing drug labels and packages in Canada
is due largely to "the lack of convincing evidence" demonstrating the need for such a
system.32 This point emphasizes the importance of reporting all anesthetic incidents, if
change is to occur.
Critics also have referred to the complexity of formulating and implementing
such a nationally accepted system. However, supporters counter that plausible
frameworks already exist. These include the (CSA) Standard for User Applied Drug
Labels in Anesthesia and Critical Care for syringes, the color codes currently applied to
gas cylinders, or even the user-applied color-coding system for anesthetic drugs
developed by the American Society for Testing and Materials (ASTM).29 Of special note
is an ASTM drug standard that calls for black “tops” with white lettering indicating that
dilution is required for all vials containing drugs that must be diluted prior to
administration.
Nevertheless, studies citing increases in drug errors with the color-coding
system, have fueled beliefs that 'complexity breeds mistakes' 33 - through encouraging
reliance on descriptive drug features, while detracting from the careful reading of drug
labels. Conversely, some practitioners argue, the use of plain, identical labels would
"necessitate the careful reading of the drug".21 Also, some clinicians believe that
14
standardized color-coding per drug category might make it harder to distinguish different
drugs in the same category. Regretfully, to date there are no data to show that color-
coding or similar standardization schemes actually reduce drug errors. Thus, as the
current controversy over the role of drug labels in risk management persists, vigilance
will always be "the foundation of sound anesthetic practice". 34
As one editorial comment affirms, "There is firm evidence that a considerable
reduction in the incidence of avoidable mortality and severe morbidity could be achieved
by the simple expedient of increased vigilance by individual anesthetists...There is a
failure to appreciate the importance of minute-to-minute observations of the 'whole'
patient...In all these cases the tragedy could have been avoided if constant vigilance
had been exercised." 35
The need for increased vigilance cannot be overstated. Whether additional
safety measures such as drug labeling systems are introduced or not, 'scrupulous
cross-checking' of the drug name, concentration and expiration date remains the most
obvious means of reducing drug error. 36 Any other cues the anesthesiologist relies on
can serve only to complement, not substitute, this basic drug identification procedure.
The foregoing notwithstanding, vigilance can never be perfect, and it may be unrealistic
to deal with drug errors by demanding that clinicians simply be “more careful”.
15
Error Etiology
Anesthetic administration incidents can result from any of the following four broad
categories of error classification drawn from Rasmussen’s model of human cognition
(“skills-rules-knowledge” model ) 37
The first form of incident includes "skill-based errors", to which even the most
experienced anesthesiologists are prone, as they often occur during highly routine
procedures.17, 37
Cited errors are reportedly precipitated by factors that include boredom, fatigue,
haste, increased workload and inattention,9 which can detract from the
anesthesiologist's ability to correctly read the drug label and more important, to properly
absorb that information, as well.
An incident reported in Britain illustrates the serious effects of drug label related
errors. During a routine dental sedation, a patient was inadvertently administered
adrenaline in place of atropine, despite the proper labeling of the drug ampule and its
double "verification" prior to injection. This seemingly minor oversight was not detected
quickly enough and patient death soon resulted.18 Classified as "technical errors",
these incidents refer to faulty execution of an otherwise correct plan or course of
action.6 They can result from the incorrect use of anesthetic devices or as mentioned
previously, be an associated risk factor of certain techniques and procedures.
16
The third category is "rule-based errors". Failure to apply a rule, such as
standard preparatory measures or routine checks, that are intended to reduce adverse
outcomes serves as an example.17, 37 To avoid these errors, adherence to protocol to
identify potential drug error sources, such as inaccurate or incomplete manufacturer
drug labels is stressed.18,19
Lastly, there are "knowledge-based errors", where the initial intention is itself
wrong, due to inadequate knowledge or experience.6, 37 Table 7 lists all of these various
types of error according to those factors most frequently cited in anesthetic critical
incident surveys.
This system of error classification has been applied in many anesthesia studies6 in its
capacity to identify underlying sources of human error. It provides a valuable source of
practical and directly relevant information when formulating preventive measures.
Modelling Human Cognition
An important contribution to our basic understanding of human error has been
Rasmussen’s model of human cognition, upon which the previous error categories are
based. The model has three distinct cognitive levels (“skills-rules-knowledge” model) 37
At the lowest, or skill-based level, behavior is unconscious, nonverbal, and automatic
(“a continuous time, feed-forward control system generating control signals apriori
based on an internal model”. Example: picking up a pen.
17
At the rule-based level, one step up in Rasmussen’s model, people use stored
(or pre-compiled) rules acquired with experience on the job. At this level, workers
recognize signs in the environment and the execute the rule associated with that sign.
Example: stopping at a stop sign when driving a car.
Rasmussen’s highest cognitive level involves knowledge-based behavior, and is
most suited when operating in unfamiliar environments where prior experience is
unavailable to provide a system of rules. Example: troubleshooting a new computer for
the first time.
Under Rasmussen’s “skills-rules-knowledge” model, human behavior moves
along this “ladder” as on-the-job experience increases. Early on, when one is placed in
an unfamiliar environment, problem-solving behavior will be at the knowledge level. As
experience is gained so that rules can be formed, the rules level takes over. In some
situations, further experience may lead to even further automation (skills level).
For each of the three cognitive levels, the way in which information and
environmental cues are perceived differs. Signals guide skill-based behavior, while
symbols apply to knowledge-based behavior. Signals supply time-space information
only, they have no meaning at higher levels, and they cannot be verbalized. Signs may
trigger rules (stop, start, etc.) or may indicate the state of system (valve open/closed)
but they do not express the functional relationships (e.g. the consequences of an open
18
valve). Finally, symbols refer to concepts that support analytical reasoning, such as
modeling the system to allow one to determine the consequences of an open valve.
What does all this have to do with avoiding drug errors? The answer lies in the
following. Rasmussen’s three levels of cognition can be grouped into two broader
categories: 1) analytical based behavior (knowledge-based behavior) and 2)
perceptual-based behavior (rule and skill based) 38 Such a categorization is important
because perceptual processing has important advantages over analytical based
behavior: analytical behavior is slow, demanding, and serial in nature whereas
perceptual behavior is fast, effortless, parallel, and less error-prone. Thus, the goal of
design should be to help people avoid situations requiring them to work at the
knowledge-based level, while supporting the use of analytical problem solving for use in
unfamiliar situations. Design guidelines that match the environment to the people
involved is known as Ecological Interface Design 38. A formal exploration of drug
ergonomics issues in the context of the Rasmussen model has not yet been
undertaken, but it would appear to have much to offer. As an example, the suggestion
that one should generally avoid working at the knowledge-based level and work
primarily at the perceptual level reinforces the notion that drug labels should include
signs (e.g., color, warning symbols) as well as information (e.g., drug name and
quantity). In this context, for instance, the suggestion sometimes made that all drug
labels should be uniform in style to force one to read them carefully amounts to making
one work more at the analytical level and less at the perceptual level.
19
Based on these and other considerations, Doyle 39 has offered the following ad
hoc approach to drug ergonomics:
Ten Ergonomic Principles in Drug Delivery
1. Labeling
Package labeling should be clear and unambiguous, with readable fonts and
sharp print contrast.
2. Warning
Special instructions or warnings should be highlighted and prominently displayed
on the packaging (e.g. drug may be sedating; please avoid heavy machinery).
3. Product Identifiability
All products should have a product code, lot number, expiration date and a
suggested route of administration. In addition, tablets should have unique
markings to allow for product recognition.
4. Generic Name
The generic (scientific) name of the drug should be prominently displayed on the
drug label.
20
5. Trade Name
The drug trade name, if displayed, should not be expected to result in drug
misidentification.
6. Dose
For tablets and other oral dosage forms, the dose of each tablet should be clearly
stated (but not necessarily as tablet markings). Tablets should be marked with a
unique identifier.
7. Concentration
Labels for drugs in liquid form should clearly indicate the concentration and
volume.
8. Strength
The strength of the product should have predominance over the number of units
in the package.
9. Safety
The drug packaging should not present a safety hazard to users (e.g. glass
ampules that disintegrate when opened).
21
10. Special Needs
Consider those patients with special needs: child-proof containers, help for
patients with limited vision, patients with arthritis.
In response to the Drug Ergonomic Principles given above, Rosen 40 made some
additional comments:
“Perhaps the most useful recommendation is to include the generic name,
perhaps in abbreviated form, as well as the strength, on each tablet or capsule.
This would be useful because many patients transfer medications to different
containers. There are few more frustrating times in my office than those involving
a new elderly patient with a pill-dispenser filled with pills and capsules of every
size, shape and colour.”
To deal with this and similar identification problems, Doyle 41 has suggested that a
multicharacter code might be used to identify drug products. For example, a three
character code could uniquely code over 50,000 different products, and might be used
for tablets, while four or five character codes allow for millions of more choices. A novel
feature of this proposal is that Internet Web technology would service users inquiring
about a drug from its code (sometimes referred to as “license plates” for drugs).
Similarly, companies wishing to register new products would go to a related but highly
secure Web site to pick a new code from the available pool and enter product
22
registration data (dosage form, generic name, brand name, strength etc.) to complete
the entries for that product in the computer database.
Conclusion
With the increasing array of anesthetic agents on the market, their growing
clinical versatility and new delivery techniques, the risk of drug administration error also
similarly increases. Hence, anesthesiologists must be made sensitive to the underlying
source and likelihood of these errors, as well as to factors which can minimize their
occurrence.
Ultimately, the anesthesiologist has the responsibility to ensure the safety of
his/her patient and to guarantee, that in all cases, the correct drug and correct dosage is
being properly administered. The above notwithstanding, the need for research and
regulations directed at the drug error problem remains strong.
23
GLOSSARY American Society for Testing and Materials (ASTM): Sets standards for User Applied
Drug Labels in Anesthesiology according to class of drug. The types of color codes
used include induction agents - yellow, opioids - blue, neuromuscular relaxants - red,
tranquilizers - orange, anticholinergics - green. Web page: http://www.astm.org
Canadian Adverse Drug Reaction Programmes: Collects reports pertaining to adverse
drug reactions.
Canadian Drug Manufacturers Association (CDMA): Collects reports pertaining to errors
resulting from drug packaging.
Canadian Drug Manufacturers Association
Suite 606, 4120 Yonge St.
North York, Ontario
M2P 2B8 CANADA
Canadian Society of Hospital Pharmacists (CSHP): Responsible for drug packaging
standards in Canada. Also collects reports pertaining to errors resulting from drug
packaging.
Canadian Society of Hospital Pharmacists
Suite 350, 1145 Hunt Club Road,
24
Ottawa, Ontario
K1V 0Y3 CANADA
Canadian Standards Association (CSA): Similar to the ASTM, this agency formulates
the Standard for User Applied Drug Labels in Anesthesia and Critical Care for
anesthesia drug syringe labels in Canada. It specifies design requirements for size,
color, pattern, shape and typeface used on labels applied to unlabeled syringes filled by
the user. Web address: http://www.cas.ca
Critical Incident/Mishap: An incident or mistake that could be harmful or potentially
harmful to the patient during management of anesthesia. Its outcome can range from
increased length of hospital stay to death.
Error: A 'flawed' plan or action which deviates from the ideal. When a planned
sequence of mental or physical activities fails to result in an intended outcome.
Food and Drug Administration (FDA): The United States federal agency whose function
includes monitoring reports of adverse drug and issues associated with drug packaging.
For more information, visit the Web at http://www.fda.gov
Hazard: A risk, peril or a source of danger.
25
Health Protection Branch of the Ministry of Health and Welfare Canada: Responsible for
approving drug packaging designs, in Canada, submitted by the PMA. For more
information visit the Canadian government health ministry on the Web at
http://www.hwc.ca
Institute for Safe Medical Practices (ISMP): A nonprofit organization that provides the
clinical community with information about adverse drug event prevention techniques.
Special strengths include relationships with other clinical organizations and an excellent
educational outreach program. Web address http://www.imsp.org
Knowledge-Based Errors: The result of formulating a wrong intention or plan due to
inadequate knowledge or experience.
MedWatch: The Medical Products Reporting Program of the U.S. Food and Drug
Administration (FDA). This program accepts reports from health professionals about
serious adverse events and product problems from drugs, medical devices, nutritional
products, etc. Reports can be made using a toll-free telephone number 1-800-FDA-
1088. Further information is available at their Web site: http://www.fda.gov/medwatch
Negligence: Failure to take proper care. Failure to prevent, recognize and treat
appropriately a well established hazard.
Pharmaceutical Manufacturers' Association (PMA): The agency responsible for
developing drug packaging designs in accordance with the criteria set by the CSHP. It
26
also addresses concerns regarding drug packaging and collects reports of drug errors
due to drug labels.
Pharmaceutical Manufacturers' Association
302-11 Prince of Wales Drive
Ottawa, Ontario K2C 3T2 CANADA
Rule-Based Errors: Failing to apply or misapplying a rule designed to avoid error or
minimize adverse outcome. This can often involve a lack of preoperative measures or
adherence to routine procedures such as equipment checks etc.
Skill-Based errors (includes slips): Errors to which skilled operators are particularly
prone. They are often a result of inattention, haste, fatigue, illness or other stress.
Slip: Temporary dissociation between two control modes for human action: the
automatic control mode and conscious control mode. Automatic control mode is fast
and efficient, drawing on habitual action sequences. Conscious control mode operates
in a novel situation, it is slow and effortful, and heavily dependent on limited cognitive
resources.
Substantive Negative Outcome (SNO): A critical incident that results in mortality,
cardiac arrest, cancelled operative procedure, extended stay in recovery room,
intensive care unit, or hospital.
27
Technical Errors: The incorrect execution of a technique that can result in an undesired
outcome or no outcome at all. This may be a result of deficiency of technical skill or
from poor human factors design in the equipment or apparatus involved.
Vigilance - The ability to sustain attention.
28
REFERENCES 1. Allnutt MF: Human factors in accidents. British Journal of Anaesthesia
1987;59(7):856-64.
2. Gaba DM, DeAnda A: The response of anesthesia trainees to simulated critical
incidents. Anesthesia & Analgesia 1989; 68:444-51.
3. Short TG, O’Regan A, Lew J, Oh TE: Critical incident reporting in an anaesthetic
department quality assurance programme. Anaesthesia 1993;48(1):3-7.
4. Cooper JB, Newbower RS, Kitz RJ: An analysis of major errors and equipment
failures in anesthesia management: considerations for prevention and detection.
Anesthesiology 1984;60:34-42.
5. Craig J, Wilson ME: A survey of anaesthetic misadventures. Anaesthesia
1981;36:933-6.
6. Runciman WB, Sellen A, Webb RK, Williamson JA, Currie M, Morgan C, Russell
WJ: Errors, incidents and accidents in anaesthetic practice. Anaesthesia &
Intensive Care 1993; 21(5):506-19.
29
7. Smellie GD, Lees NW, Smith EM: Drug recognition by nurses and anaesthetists.
Anaesthesia 1982;37(2):206-8.
8. Kumar V, Barcellos WA, Mehta MP, Carter JG: An analysis of critical incidents in a
teaching department for quality assurance. A survey of mishaps during
anaesthesia. Anaesthesia 1988;43:879-83.
9. Currie M, Mackay P, Morgan C, Runciman WB, Russell WJ, Sellen A, Webb RK,
Williamson JA: The “wrong drug” problem in anaesthesia: an analysis of 2000
incident reports. Anaesthesia & Intensive Care 1993;21(5):596-601.
10. Macdonald R: Problems with regional anaesthesia: hazards or negligence? British
Journal of Anaesthesia 1994;73(1):64-8.
11. Stedmon J, Hammond J: Inadvertent epidural midazolam and fentanyl. Anaesthesia
1989;44(1):75.
12. Chong M, Davis TP: Accidental intra-arterial injection of propofol. Anaesthesia
1987;42(7):781.
13. Cooper J, Newbower Ronald, Long C, McPeek B: Preventable Anesthesia
Mishaps: A study of human factors. Anesthesiology 1978;49(6): 399-406.
30
14. Noble J, Kennedy DJ, Latimer RD, Hardy I, Bethune DW, Collis JM, Wallwork J:
Massive lignocaine overdose during cardiopulmonary bypass. British Journal of
Anaesthesia 1984;56(12):1439-41.
15. Edgren B, Tilelli J, Gehrz R: Intravenous lidocaine overdosage in a child. Journal of
Toxicology - Clinical Toxicology 1986;24(1):51-8.
16. Chalmers P: Etomidate - overdose by continuous infusion. Anaesthesia
1983;38(5):506.
17. Williamson JA, Webb RK, Sellen A, Runciman WB, Van der Walt JA: Human
failure: an analysis of 2000 incident reports. Anaesthesia Intensive Care
1993;21:678-83.
18. Uncles DR: The importance of checking ampule labels. Anaesthesia
1993;48(2):180-1.
19. Kennedy RW, Till W, Shah JB: Imprecise fentanyl and sufentanil labels. Anesthesia
& Analgesia 1989;69(1):137-8.
20. Gaba DM, Maxwell M, DeAnda A: Anesthetic mishaps: breaking the chain of
accident evolution. Anesthesiology 1987; 66:670-6.
31
21. Orser BA, Oxorn DC: An anaesthetic drug error: minimizing the risk. Canadian
Journal of Anaesthesia 1994;41(2):120-4.
22. Rheinstein PH, McGinnis TJ: Medication errors. American Family Physician
1992;45(6):2720-2.
23. Goresky GV, Pipa D: Drug labels on anaesthesia carts. Canadian Journal of
Anaesthesia 1994;41(7):655.
24. Shanker KB, Palkar NV, Nishkala R: Paraplegia following epidural potassium
chloride. Anaesthesia 1985;40(1):45-7.
25. Gilron I: The introduction of new drugs into anaesthetic practice: a perspective in
pharmaceutical development and regulation. Canadian Journal of Anaesthesia 1995;
42(6):516-22.
26. Bedford RF: The FDA protects the public by regulating the manufacture of
anesthetic agents and the production devices used in anesthetic practice.
Anesthesiology 1995;82(1):33A.
27. FDA Homepage: Reinventing regulation of drugs and medical devices.
www.fda.gov/po/reinvent.html
32
28. Rendell-Baker L: Reducing syringe swap errors. Anesthesiology 1993;78(3):623.
29. Dain S: Drug labelling. Canadian Journal of Anaesthesia 1994;41(8):755.
30. Kalish MA: Be aware and read. Anesthesia & Analgesia 1985; 64(2):179.
31. Sykes P: Accidents do not happen - they are caused. Anesthesia Progress
1992;39(4-5):111-7.
32. Orser BA, Oxorn DC, Yee: Drug errors. Canadian Journal of Anaesthesia
1994;41(9):870-80.
33. Parr MJA: Labelling drugs. Anaesthesia 1986;41:222.
34. Kempen PM: Unintentional lethal / toxic injections: elimination of drugs versus
vigilance. Anesthesiology 1988; 68:477.
35. Green RA: A matter of vigilance. Anaesthesia 1986;41:129-130.
36. Dror A, Henriksen E: Accidental epidural magnesium sulfate injection. Anesthesia &
Analgesia 1987;66:1020-1.
33
37. Rasmussen J. Information Processing and Human-Machine Interaction. North
Holland, New York, 1986
38. Vincente KJ, Rasmussen J. Ecological Interface Design: Theoretical
Foundations. IEEE Transactions on Systems, Man and Cybernetics, 1992; 22(4)
: 589-606
39. Doyle DJ. Drug packaging (letter). Canadian Medical Association Journal
1997;156:764
40. Rosen NA. Action long overdue on drug labelling (letter). Canadian Medical
Association Journal 1997;156:1383
41. Doyle DJ. License plates for drugs (letter). Canadian Medical Association Journal
1997;157(12):1739
42. Goonewardene TW, Sentheshanmuganathan S, Kamalanathan S,
Kanagasunderam R: Accidental subarachnoid injection of gallamine. A case
report. British Journal of Anaesthesia 1975;47:889-93.
43. Jonville AP, Barbier P, Blond MH, Boscq M, Autret E, Breteau M: Accidental
lidocaine overdosage in an infant. Journal of Toxicology - Clinical Toxicology
1990;28(1):101-6.
34
44. Edgren B, Gehrz R: Intravenous lidocaine overdosage in a child. Journal of
Toxicology - Clinical Toxicology 1986; 24(1):51-8.
45. Cardan E: Intrathecal frusemide. Anaesthesia 1985; 40(10):1025.
46. Ziser A, Sorenson EJ, Bluestein LS, Ronan KP: Epidural injection of aztreonam.
Canadian Journal of Anaesthesia 1994;41(6):553.
47. Ward CF, Sanford TJ: A potential hazard: interchanging fentanyl and sufentanil.
Anesthesiology 1986;64(3):410-1.
48. Yemen TA: Drug errors. Canadian Journal of Anaesthesia 1994;41(9):870-1.
49. Alistair IF, Daly PA, Dorian P, Tough J: Reversible 'cardiomyopathy' after accidental
adrenaline overdose. The American Journal of Cardiology 1991;67(4):318-9.
50. Ikeda S, Schweiss JF: Life-threatening similarity in drug packaging. Anesthesiology
1982;56(6):489-91.
51. Arditis J, Tsacona H, Giala M: Accidental administration of adrenaline during i.v.
regional anaesthesia. British Journal of Anaesthesia 1984;56(8):923-4.
35
52. Tuohy SA, MacEvilly MA: Inadvertent injection of thiopentone to the brachial plexus
sheath. British Journal of Anaesthesia 1982;54(3):355-7.
53. Forestner JE, Raj PP: Inadvertent epidural injection of thiopenal: a case report.
Anesthesia & Analgesia 1975; 54(3):406-7.
54. Lessard MR, Mathieu M, Fafard, M: Similarity of drug labels predisposes to drug
errors. Canadian Journal of Anaesthesia 1993;40(11):1109.
55. Menon MRB, Lett Z: Incorrectly filled cylinders. Anaesthesia 1991;46:155-6.
56. Jawan B, Lee JH: Cardiac arrest caused by an incorrectly filled oxygen cylinder: a
case report. British Journal of Anaesthesia 1990;64:749-51.
57. Peduto VA, Gungui P, Di Martino MR, Napoleone M: Accidental subarachnoid
injection of pancuronium. Anesthesia & Analgesia 1989;69(4):516-7.
58. Munson ES: Mepivacaine overdose in a child. Anesthesia & Analgesia
1973;52(3):422-4.
59. Bricker SRW: Overdose of ritodrine. Anaesthesia 1989; 44(10):864.
36
60. Zveibil FR, Monies-Chass I: Accidental intra-arterial Injection of ketamine.
Anaesthesia 1976;31(8):1084-5.
61. Inadvertent intravascular injections during lumbar epidural anesthesia.
Anesthesiology 1981;54(2):172-3.
62. O'Hanlon J, Allen RW: Inadvertent spinal block during epidural analgesia in an
anaesthetized patient. European Journal of Anaesthesiology 1994;11(2):135-8
63. Evans PJD, Lloyd JW, Wood GJ: Accidental intrathecal injection of bupivaciane
and dextran. Anaesthesia 1981; 36(7):685-7.
64. Robbins PM, Fernando R, Lim GH: Accidental intrathecal insertion of an extradural
catheter during combined spinal-extradural anaesthesia for caesarean section. British
Journal of Anaesthesia 1995;75(3):355-7.
65. Holley HS, Cuthrell L: Intraarterial injection of propofol. Anesthesiology
1990;73(1):183-4.
66. Ross HT: Intra-arterial thiopental. Anesthesiology 1982; 57(6):543.
37
67. Vangerven M, Delrue G, Brugman E, Cosaert P: A new therapeutic approach to
accidental intra-arterial injection of thiopentone. British Journal of Anaesthesia 1989;
62(1):98-100.
68. Tartiere J, Gerard J, Peny J, Hurpe J, Quesnel J: Acute treatment after accidental
intrathecal injection of hypertonic contrast media. Anesthesiology 1989;71(1):169.
69. Gabrielczyk, MR, Forensky J: Inadvertent intra-arterial injection of vecuronium.
Anesthesiology 1988;68:656-657.
70. Arthurs GJ, Davies R: Atropine - a safe drug: Anaesthesia 1980;35(11):1077-9.
71. Madej TH, Ellis FR, Halsall PJ: Prolonged femoral nerve block with 0.5%
bupivaciane. Anaesthesia 1988;43(7):607-8.
72. Carter BT, Westfall VK, Heironimus TW, Atuk NO: Severe reaction to accidental
subcutaneous administration of large doses of epinephrine. Anesthesia & Analgesia
1971; 50(2):175-8.
73. Ryan JP, Meakin G: Fentanyl overdose in a neonate: use of naloxone infusion.
Anaesthesia 1989;44(10):864-5.
38
74. Moon RE, Clements FM: Accidental epidural overdose of hydromorphone.
Anesthesiology 1985;63(2):238-9.
75. Antonelli D, Ben-Ami M, Weiss Z: Sinus standstill following accidental lidocaine
overdose. American Heart Journal 1984; 107(5):1042-4.
76. Finkelstein F, Kreeft J: Massive lidocaine poisoning. New England Journal of
Medicine 1979;301(1):50.
77. Yukioka H, Hayashi M, Fujimori M: Lidocaine intoxication during general
anesthesia. Anesthesia & Analgesia 1990; 71(2):207-8.
78. Atanassoh P, Aton E: Accidental epidural injection of a large dose of morphine.
Anaesthesia 1988;43(12):1056.
79. Pomonis SP, Economacos G, Costopanajiocoy SP: Overdose of intrathecal
morphine. Anaesthesia 1986;41(6):670.
80. Charlton AJ, Harper NJN, Edwards D, Wilson AC: Atracurium overdose in a small
infant. Anaesthesia 1989;44:485-6.
81. Dunne J, Wise C: The pump that gave too much: accidental overinfusion of
prostacyclin. Anaesthesia 1991;46(1):75.
39
82. Shenkman Z, Ornstein E, Adler: Drug overdose as a consequence of misuse of a
syringe pump. Anesthesia & Analgesia 1995;81(3):652-3.
83. Forrest ETS, Vanner RG: ‘Overdose’ of vecuronium. Anaesthesia
1990;45(11):997.
40
TABLE 1
Drugs most frequently involved in “wrong drug”
incidents - “intended” drugs
Drug # Incidents
Opioids 21
Nondepolarizing Relaxants 20
Succinylcholine (Suxamethonium) 10
Saline/Water 9
Local Anaesthetics 8
Vasopressors 8
Atropine only 7
Atropine/Neostigmine 6
Midazolam 6
Antibiotics 5
Hypotensive Agents 5
Thiopentone 3
Nil (including 11 volatile agents) 13
Others 23
Source: Currie M, Mackay P, Morgan C, Runciman WB, Russell WJ,
Sellen A, Webb RK, Williamson JA: The “wrong drug” problem in
anaesthesia: an analysis of 2000 incident reports. Anaesthesia
& Intensive Care 1993;21(5):596-601.
41
TABLE 2
Drugs most frequently involved in
“wrong drug” incidents - “selected” drugs
Drug # Given
Nondepolarizing Relaxants 23
Succinylcholine (Suxamethonium) 15
Vasopressors 11
Volatile Anesthetic 14
Opioids 10
Local Anesthetics 5
Hypotensive agents 6
Atropine/neostigmine 6
Midazolam 5
Water/saline 3
Thiopentone 3
Others 14
Source: Currie M, Mackay P, Morgan C, Runciman WB, Russell WJ,
Sellen A, Webb RK, Williamson JA: The “wrong drug” problem in
anaesthesia: an analysis of 2000 incident reports. Anaesthesia
& Intensive Care 1993;21(5):596-601.
42
TABLE 3
Syringe and Ampule Errors in Anesthesia
Category % of All “Wrong Drugs”
(114)
% of Category
Syringe Error 40 100
Same Size 20 52
Correctly labeled 24 63
Assisting personnel 11 29
Ampule Error 33 100
Similar ampule 18 54
Wrong location 8 23
Assisting personnel 5 15
Source: Currie M, Mackay P, Morgan C, Runciman WB, Russell WJ, Sellen A, Webb RK,
Williamson JA: The “wrong drug” problem in anaesthesia: an analysis of 2000
incident reports. Anaesthesia & Intensive Care 1993;21(5):596-601.
43
TABLE 4 Drugs which ordinarily should not be given by
bolus injection
Dopamine
Dobutamine
Digoxin
Erythromycin
Isoproteranol
Norepinephrine
Phenytoin
Potassium
Ritodrin
Vancomycin
Note: Does not include oncology drugs
44
TABLE 5
Drugs which have been confused by anesthetists # incidents
Adrenaline/atropine
Potassium chloride/calcium chloride 81
Water/aminophylline 2
Methlyprednisone/hydrocortisone 1
Pethidine/atropine 10
Ergometrine/atropine 3
Neostigmine/atropine 1
Calcium chloride/water 1
Curare/morphine 1
Vitamin K/neostigmine 1
Curare/suxamethonium 4
Alcuronium/neostigmine 2
Source: Smellie GD, Lees NW, Smith EM: Drug recognition by nurses and
anesthetists. Anaesthesia 1982;37(2):206-8.
45
TABLE 6
A drug labeling scheme designed to facilitate recognition
Generic Name Propriety Name
ATRAcurium TRAcrium
DOXAcurium NUROmax
MIVAcurium MIVEcron
VECuronium NORcuron
PIPEcuronium ARDuan
PANcuronium PAVulon
Source: Rendell-Baker L: Reducing syringe swap errors.
Anesthesiology 1993;78(3):623.
46
TABLE 7 Factors associated with critical incidents
Inadequate total experience Inadequate familiarity with equipment/device Poor communication with team, lab, etc. Haste Inattention/carelessness Fatigue Excessive dependency on other personnel Failure to perform a normal check Training or experience - other factors Visual field restricted Mental or physical - other factors Inadequate familiarity with surgical procedure Distraction Poor labeling of controls, drugs, etc. Supervision - other factors Source: (modified from) Cooper JB, Newbower RS, Kitz RJ: An
analysis of major errors and equipment failures in anesthesia
management: considerations for prevention and detection.
Anesthesiology 1984;60:34-42.
47
CASES OF DRUG ERROR IN ANESTHESIA
(primary source of error)
TABLE 8(a) Wrong Drug Administration
# CASES DRUG/DOSE INTENDED DRUG/DOSE ADMINISTERED ROUTE CAUSE OF ERROR SEQUELAE 1 Bupivacaine Magnesium sulfate epidural technique none
36
1 Bupivacaine (.125%) Midazolam and Fentanyl epidural equipment misuse none11
1 Cinchocaine Gallamine intrathecal ampule swap none42
1 Contrast iodine 50 mg Lidocaine intravenous swap none43
1 Dextrose (5%) 1160 mg Lidocaine HCl intravenous drug swap none44
1 Distilled water 15 ml KCl (15%) epidural ampule swap paraplegia24
1 Dixidextracaine 2 ml Frusemide (40mg) intrathecal ampule swap none45
1 4-6ml/hr Fentanyl 1 g Aztreonam in 100ml D5W epidural misread label none46
1 1ml Fentanyl 1ml Sufentanyil axillary ampule swap none47
2 Glycopyrrolate Epinephrine intravenous ampule swap none21
1 Lidocaine (2%) 7mg Epinephrine (.1%) cervical swap none49
1 2ml Lidocaine (2%) 500 mcg Epinephrine (.01%) intravenous syringe swap none50
1 Lidocaine ointment (5%) Nitroglycerin ointment (2%) endotracheal
tubes similar label none
30
1 Lignocaine (.5%) Lignocaine (.5%) with
adrenaline (1:80000) intravenous swap none
51
48
1 Lignocaine (1%) with
adrenaline 15ml Thiopentone (2.5%) axillary route to
brachial plexus
sheath
syringe swap none52
1 30ml local anesthetic 15ml Thiopentol (2%) epidural syringe swap none53
1 10mg Metocurine 62.5mg Dobutamine intravenous similar labels none54
3 Nitrous oxide Carbon dioxide airway cylinder misfilled none55
2 Oxygen Carbon dioxide airway cylinder
mislabelled none
56
1 2ml Pancuronium
bromide (4mg) 2ml Hyperbaric (1%)
bupivacaine solution subarachnoid
space ampule swap none
57
1 Radiopaque 15ml Mepivacaine (300mg) intravenous - none58
1 50mg Ranitidine 50mg Ritrodrine intravenous ampule swap none59
49
TABLE 8(b) Route Administration Error
# CASES ROUTE INTENDED ROUTE
ADMINISTERED WRONG
DRUG DRUG ADMINISTERED CAUSE OF ERROR
1 dorsal pedis artery intra-arterial no 2ml Ketamine (5%) equipment misuse60
194 epidural intravascular no epidural block associated risk61
1 epidural subarachnoid no 8ml Bupivacaine (.5%) associated risk62
1 extradural intrathecal no Bupivacaine (.375%) in
8ml of Dextran associated risk
63
1 extradural intrathecal no Bupivacaine (.5%)
in glucose (8%) associated risk
64
1 intravenous brachial artery no 4ml Propofol associated risk12
1 intravenous intra-arterial no 8ml Propofol (1%) equipment misuse65
1 intravenous radial artery no 150-175mg Thiopentol
(2.5%) associated risk
66
1 intravenous intra-arterial no 400mg Thiopentone
(2.5%) associated risk
67
1 subarachnoid intrathecal no 10ml of hypertonic
solution of Amidotrizoate associated risk
68
1 intra-arterial intravenous no 2mg Vecuronium equipment misuse69
50
TABLE 8(c) Dosage Error Administration
# CASES DRUG/DOSE ADMINISTERED DEGREE OF
OVERDOSE CAUSE OF ERROR SEQUELAE
3 Atropine sulphate (.3mg/5ml) 1000X dispenser minor70
1 180 mg Bupivacaine (.5%) 2X dilution minor71
1 5mg Epinephrine (.05%) subcutaneous dilution none72
1 100 g Fentanyl 13X misread label none73
1 Etomidate 250 mg over 43 minutes 10X death due to
secondary
causes 16
1 5mg Hydromorphone 10X dilution none74
2 500mg Lidocaine 10X misread label none75
1 1g Lidocaine 20X assistant none76
1 1000mg Lidocaine 10X misread label none77
1 2g Lignocaine 10X syringe swap none14
4 15 mg Morphine 10X dilution none79
1 200mg Morphine 50X assistant none78
51
TABLE 8(d) Speed Error Administration
# CASES DRUG AND SPEED INTENDED SPEED ADMINISTERED DEGREE
FASTER COMMENTS
1 4mg Atracurium over 75 minutes 37mg over 75 minutes 10X equipment misuse80
1 2.5ml Epoprostenol/hour 50ml in less than an hour 20X faulty equipment81
1 50mg Morphine and 50mg
Midazolam in 50ml solution 50ml over 10 minutes 150X syringe misuse
82
1 1.5mg/hour of Vecuronium 37mg/hour 25X death 83
52
53
LIST OF TABLES
TABLE 1
Drugs most frequently involved in “wrong drug” incidents - “intended” drugs
TABLE 2
Drugs most frequently involved in “wrong drug” incidents - “selected” drugs
TABLE 3
Syringe and ampule errors in anesthesia
TABLE 4
Drugs which ordinarily should not be given by bolus injection
TABLE 5
Drugs which have been confused by anesthetists
TABLE 6
A drug labeling scheme designed to facilitate recognition
TABLE 7
Factors associated with critical incidents
TABLE 8
CASES OF DRUG ERROR IN ANESTHESIA (primary source of error)
TABLE 8(a) Wrong Drug Administration TABLE 8(b) Route Administration Error TABLE 8(c) Dosage Error Administration