Safety in Anesthesia

Solmaz Poorsattar Manuel

May Pian-Smith

I. SAFETY IN ANESTHESIA

A. Anesthesiology has led the patient safety movement, and anesthesia-related adverse outcomes have drastically declined since the 1960s. Despite this decline, the risks of both general and regional anesthesia remain. Recent data suggest that anesthetic-related mortality is 0.5 to 1/100,000 in the developed world.

B. Adverse events are injuries resulting from medical care. Many systems and human factor errors can contribute to adverse events. Reason’s “Swiss cheese model” of adverse event causation describes how, although many layers of defense lie between hazards and adverse events, there are gaps in each layer that, if aligned perfectly, can allow an event to occur.

C. Errors can occur despite a practitioner’s expertise, experience, and good intention. In the perioperative arena, errors can result from the following:

1. Organizational influences including production pressure or improperly maintained equipment

2. Inadequate supervision, which includes the unavailability of attending anesthesiologists to immediately assist junior residents

3. Preconditions for unsafe acts include fatigued clinicians or improper communication practices

4. Specific individual acts

D. Preventing adverse events therefore relies on optimizing practitioners’ understanding of the system and resources of their workplace, in addition to individual practice improvement. Strategies to create safer systems include the following:

1. Simplification

2. Standardization

3. Improving teamwork and communication

4. Developing an organizational culture that promotes learning from past mistakes. Strategies for individuals to decrease various types of errors are described below.

II. TYPES OF ERRORS

Errors are acts of commission (doing something wrong) or omission (failing to do the right thing) leading to an undesirable outcome. Anesthesiologists should be aware of, and actively work to mitigate, common types of errors.

A. Medication Errors. It is estimated that at least 5% of hospital patients experience an adverse drug event. The cost of preventable medication errors in US hospitals has been estimated at $16.4 billion annually.

1. Examples of medication errors include administration of an inappropriate dose, administration through an inappropriate route, administration at an inappropriate rate, and administration to the incorrect patient. Some specific examples as follows:

a. The rapid intravenous (IV) administration of undiluted dilantin or undiluted potassium can cause cardiovascular collapse or death.

b. Neostigmine administered without a corresponding antimuscarinic drug can lead to severe bradycardia, asystole, and death.

c. Inadvertent administration of a medication to which a patient has a known allergy.

2. Strategies to decrease medication errors:

a. Have a thorough understanding of the pharmacokinetics, pharmacodynamics, and effects of each medication administered.

b. Exercise extreme vigilance in drug administration. Double-check medications prior to administration and consider implementing the “Five Rights” checklist: right patient, right route, right dose, right time, and right drug prior to each administration.

c. Have only unit dosing available in the patient care area. Unit dosing refers to packaging medications in quantities and concentrations that are safe and appropriate for administration without dilution.

d. Involve clinical pharmacists during ICU rounds. Pharmacists can provide assistance with drug dosing questions and help identify medication errors immediately.

e. Perform careful medication reconciliation when transitioning care between the floor, ICU, and OR. Medical reconciliation is the process of reviewing a patient’s complete medication regimen on both ends of care to avoid unintended inconsistencies. Avoid confusing and potentially hazardous abbreviations. The Joint Commission has issued a list of high-risk “do not use” abbreviations. http://www.jointcommission.org/assets/1/18/Do_Not_Use_List.pdf

f. Consider bar coding technology to decrease medication identification errors.

B. Procedure Errors

1. Examples of procedure errors include wrong-site surgery, retained instruments, and operating room fires. Higher volumes of certain surgeries or procedures being performed by a single physician or institution have been associated with better outcomes.

2. Strategies to reduce procedure errors:

a. “Universal Protocols” should be implemented including signing site of surgery, using preprocedural time-outs, and using checklists.

b. Intraoperative surgical instrument and sponge counts are used to prevent retention of surgical instruments in the patient. If the instrument counts at the end of the procedure indicate that an instrument is missing, radiography of the operative field is conducted in the OR to determine whether the instrument is in the patient.

c. Recognize and avoid the fire safety triangle: ignition source (electrocautery, lasers) plus fuel source (gauze, drapes, ETT) plus oxidizers (oxygen, nitrous oxide) equals fire.

d. The positive volume-outcome relationship for procedures argues for simulation training and specialization. Robust competency
training should take place for procedures such as vascular catheterization, advanced intubation techniques, and bedside ultrasound use.

C. Cognitive errors are not due to faulty knowledge, but involve faulty thought processes and subconscious biases. Cognitive errors are important contributors to missed diagnoses and patient injury.

1. Examples of cognitive errors: Table 8.1 lists 14 common cognitive errors.

TABLE 8.1 Cognitive Error Catalogue

Cognitive Error	Definition	Illustration
Anchoring	Focusing on one issue at the expense of understanding the whole situation	While troubleshooting an alarm on an infusion pump, you are unaware of sudden surgical bleeding and hypotension
Availability bias	Choosing a diagnosis because it is in the forefront of your mind due to an emotionally charged memory of a bad experience	Diagnosing simple bronchospasm as anaphylaxis because you once had a case of anaphylaxis that had a very poor outcome
Premature closure	Accepting a diagnosis prematurely, failure to consider reasonable differential of possibilities	Assuming that hypotension in a trauma patient is due to bleeding, and missing the pneumothorax
Feedback bias	Misinterpretation of no feedback as “positive” feedback	Belief that you have never had a case of unintentional awareness, because you have never received a complaint about it
Confirmation bias	Seeking or acknowledging only information that confirms the desired or suspected diagnosis	Repeatedly cycling an arterial pressure cuff, changing cuff sizes, and locations, because you “do not believe” the low reading
Framing effect	Subsequent thinking is swayed by leading aspects of initial presentation	After being told by a colleague, “this patient was extremely anxious preoperatively,” you attribute postoperative agitation to her personality rather than low blood sugar
Commission bias	Tendency toward action rather than inaction. Performing unindicated maneuvers, deviating from protocol. May be due to overconfidence, desperation, or pressure from others	“Better safe than sorry” insertion of additional unnecessary invasive monitors or access; potentially resulting in a complication
Overconfidence bias	Inappropriate boldness, not recognizing the need for help, tendency to believe we are infallible	Delay in calling for help when you have trouble intubating, because you are sure you will eventually succeed
Omission bias	Hesitation to start emergency maneuvers for fear of being wrong or causing harm, tendency toward inaction	Delay in calling for chest tube placements when you suspect a pneumothorax, because you may be wrong and you will be responsible for that procedure
Sunk costs	Unwillingness to let go of a failing diagnosis or decision, especially if much time/resources have already been allocated. Ego may play a role	Having decided that a patient needs an awake fiberoptic intubation, refusing to consider alternative plans despite multiple unsuccessful attempts
Visceral bias	Countertransference; our negative or positive feelings about a patient influencing our decisions	Not troubleshooting on epidural for a laboring patient, because she is “high maintenance” or a “complainer”
Zebra retreat	Rare diagnosis figures prominently among possibilities, but physician is hesitant to pursue it	Try to “explain away” hypercarbia when MH should be considered
Unpacking principle	Failure to elicit all relevant information, especially during transfer of care	Omission of key test results, medical history, or surgical event
Psych-out error	Medical causes for behavioral problems are missed in favor of psychological diagnosis	Elderly patient in PACU is combative—prescribing restraints instead of considering hypoxia
From Stiegler MP, Neelankavil JP, Canales C, et al. Cognitive errors detected in anaesthesiology: a literature review and pilot study. Br J Anaesth 2012;108(2):229-235.