DESCRIPTION

• Preoperative medical evaluation involves assessing the risk of the planned surgical procedure, evaluating risks specific to the individual patient, and determining functional status of the patient.
• Following the above assessment, the examiner formulates recommendations for the surgeon and anesthesiologist. Additional recommendations may be given to the patient as well.

EPIDEMIOLOGY

There is an approximate 3% risk of death, myocardial infarction (MI), or ischemia cerebrovascular accident (CVA) for noncardiac surgery. MI may occur in up to 20% of patients after noncardiac surgery (1). Overall patient morbidity and mortality related to surgery may be decreasing. Preoperative patient evaluation and subsequent optimization of perioperative care can reduce both postoperative morbidity and mortality.

RISK FACTORS

Factors influencing risk of adverse surgical outcomes may be divided as follows:

• Patient functional capacity (2): Exercise tolerance is one of the most important determinants of cardiac risk.
  • Self-reported exercise tolerance may be a useful predictive tool when assessing risk. Patients unable to achieve >4–metabolic equivalents (METs) (see in the “Diagnosis” section) during daily activities have increased perioperative cardiac and long-term risks. Structured questionnaires such as the Duke Activity Status Index provide better prognostic accuracy to assess functional status (3).
  • Patients who report good exercise tolerance require minimal, if any, additional testing.
• Risk of the surgery
  • High-risk surgeries (>5% risk) include intrathoracic, intra-abdominal, suprainguinal vascular procedures, or emergency surgeries. Low risk surgeries (<1% risk) are superficial procedures, breast surgery, endoscopic procedures, and most ambulatory surgeries. All others would fall under intermediate risk (1–5%). Urgent and emergent surgeries have higher risk (4).
• Risks associated with patient medical conditions (5)
  • History of ischemic heart disease, the presence of decompensated heart failure (HF) or a history of prior congestive heart failure (CHF), CVA, diabetes mellitus (DM) (especially) requiring insulin, and renal insufficiency (creatinine >2 mg/dL)
  • Bleeding risk/history of bleeding, prior anesthesia complications, uncontrolled asthma/COPD/obstructive sleep apnea (OSA), and immunosuppression may also increase risk.
  • Patients >70 years of age are at higher risk for complications, longer length of stay, and mortality. Assess frailty risk using available calculators for geriatric patients.