The preoperative evaluation serves multiple purposes. One purpose is to identify those patients whose outcomes likely will be improved by implementation of a specific medical treatment (which rarely may require that planned surgery be rescheduled). Another purpose of the preoperative evaluation is to identify patients whose condition is so poor that the proposed surgery might only hasten death without improving the quality of life. A patient’s preoperative evaluation can uncover findings that will change the anesthetic plan. Another purpose of the preoperative evaluation is to provide the patient with an estimate of anesthetic risk. However, 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.” Finally, the preoperative evaluation presents an opportunity for the anesthesiologist to describe the proposed anesthetic plan in the context of the overall surgical and postoperative plan, provide the patient with psychological support, and obtain informed consent from the patient.
By convention, physicians in many countries use the American Society of Anesthesiologists’ (ASA) physical status classification to define relative risk prior to conscious sedation or surgical anesthesia (Table 13–1). The ASA physical status classification has many advantages: it is time-tested, simple, and reproducible, and, most importantly, it has been shown to be strongly associated with perioperative risk.
Table 13–1.American Society of Anesthesiologists’ Physical Status Classification of Patients1 ||Download (.pdf) Table 13–1. American Society of Anesthesiologists’ Physical Status Classification of Patients1
|Class ||Definition |
|1 ||Normal healthy patient |
|2 ||Patient with mild systemic disease (no functional limitations) |
|3 ||Patient with severe systemic disease (some functional limitations) |
|4 ||Patient with severe systemic disease that is a constant threat to life (functionality incapacitated) |
|5 ||Moribund patient who is not expected to survive without the operation |
|6 ||Brain-dead patient whose organs are being removed for donor purposes |
|E ||If the procedure is an emergency, the physical status is followed by “E” (eg, “2E”) |
Elements of the Preoperative History
The focus of preoperative cardiac assessment should be on determining whether the patient would benefit from further cardiac evaluation or interventions prior to the scheduled surgery. In general, the indications for cardiovascular investigations are the same in elective surgical patients as in any other patient with a similar medical condition. The fact that a patient is scheduled to undergo elective surgery does not change the indications for testing to diagnose coronary artery disease.
Perioperative pulmonary complications, most notably ...