Chapter 18. Preoperative Assessment, Premedication, & Perioperative Documentation

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  The cornerstones of an effective preoperative evaluation are the history and physical examination, which should include a complete account of all medications taken by the patient in the recent past, all pertinent drug and contact allergies, and responses and reactions to previous anesthetics.
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  The anesthesiologist should not be expected to provide the risk-versus-benefit discussion for the proposed procedure; this is the responsibility and purview of the responsible surgeon or “proceduralist.”
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  By convention physicians in many countries use the American Society of Anesthesiologists’ classification to identify relative risk prior to conscious sedation and surgical anesthesia.
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  In general, the indications for cardiovascular investigations are the same in surgical patients as in any other patient.
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  Adequacy of long-term blood glucose control can be easily and rapidly assessed by measurement of hemoglobin A1c.
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  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), warfarin should be replaced by intravenous heparin or, more commonly, by intramuscular heparinoids to minimize the risk.
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  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 requires prolonged dual antiplatelet therapy) be used in patients expected to undergo a surgical procedure within 12 months after the intervention.
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  There are no good outcomes 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; indeed, there is evidence that nondiabetic patients should be encouraged to drink glucose-containing fluids up to 2 h before induction of anesthesia.
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  To be valuable, preoperative testing must discriminate: an increased perioperative risk exists when the results are abnormal (and unknown); a reduced risk exists when the abnormality is absent or detected (and perhaps corrected).
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  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.
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  Premedication should be given purposefully, not as a mindless routine.
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  Incomplete, inaccurate, or illegible records unnecessarily complicate defending a physician against otherwise unjustified allegations of malpractice.

The cornerstones of an effective preoperative evaluation are the medical history and physical examination, which should include a complete account of all medications taken by the patient in the recent past, all pertinent drug and contact allergies, and responses and reactions to previous anesthetics. Additionally, this evaluation should include any indicated diagnostic tests, imaging procedures, or consultations from other physicians. The preoperative evaluation guides the anesthetic plan: inadequate preoperative planning and incomplete patient preparation are commonly associated with anesthetic complications.

The preoperative evaluation serves multiple purposes. One purpose is to identify those few patients whose outcomes likely will be improved by implementation of a ...