Chapter 18: Preoperative Assessment, Premedication, & Perioperative Documentation

KEY CONCEPTS

• The cornerstones of an effective preoperative or preprocedure evaluation are the history and physical examination, which should include a complete and up-to-date listing of all medications taken by the patient in the recent past, all pertinent allergies, and responses and reactions to previous anesthetics.

• The anesthesiologist should not be expected to provide the risk-versus-benefit discussion for the proposed surgery or procedure; this is the responsibility and purview of the responsible surgeon or “proceduralist.”

• By convention physicians in many countries use the American Society of Anesthesiologists’ classification to identify relative risk prior to conscious sedation and surgical anesthesia.

• In general, the indications for cardiovascular investigations are the same in elective surgical patients as in any other patient with a similar medical condition.

• Adequacy of long-term blood glucose control can be easily and rapidly assessed by measurement of hemoglobin A_1c.

• In patients deemed at high risk for thrombosis (eg, those with certain mechanical heart valve implants or with atrial fibrillation and a prior thromboembolic stroke), chronic anticoagulants should be replaced by intramuscular low-molecular-weight heparins or by intravenous unfractionated heparin.

• Current guidelines recommend postponing all but mandatory emergency surgery until at least 1 month after any coronary intervention and suggest that treatment options other than a drug-eluting stent (which will require prolonged dual antiplatelet therapy) be used in patients expected to undergo a surgical procedure within 12 months after the intervention.

• There are no good data to support restricting fluid intake (of any kind or any amount) more than 2 h before induction of general anesthesia in healthy patients undergoing elective procedures; moreover, there is strong evidence that nondiabetic patients who drink fluids containing carbohydrates and protein up to 2 h before induction of anesthesia suffer less perioperative nausea and dehydration than those who are fasted longer.

• To be valuable, preoperative testing must discriminate: There must be an avoidable increased perioperative risk when the results are abnormal (and the risk will remain unknown if the test is not performed), and when testing fails to detect the abnormality (or it has been corrected), there must be reduced risk.

• The utility of a test depends on its sensitivity and specificity. Sensitive tests have a low rate of false-negative results and rarely fail to identify an abnormality when one is present, whereas specific tests have a low rate of false-positive results and rarely identify an abnormality when one is not present.

• Premedication should be given purposefully, not as a mindless routine.

• Incomplete, inaccurate, or illegible records unnecessarily complicate defending a physician against otherwise unjustified allegations of malpractice.