PRACTICE RECOMMENDATIONS
• Identify cardiac, pulmonary, renal, infectious, and hematologic risk factors, and steps that can be taken to minimize risk. C
• Check serum albumin levels of all patients at risk for hypoalbuminemia; levels <35 g/L are strongly associated with postoperative pulmonary complications. B
• Help patients with diabetes achieve optimal glycemic control prior to surgery to minimize the risk of infection. B
• Avoid routine use of ancillary testing; evidence supports the use of such tests in only a small minority of surgical candidates. C
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
CASE Charlie H, an elderly man who has been your patient for more than 10 years, is scheduled for inguinal hernia repair, and has come in for a preoperative evaluation. Based on his medical history and a physical examination, you identify several risk factors for surgical complications: a low functional capacity (<4 METS), obesity (BMI=39), advanced age (70 years), and type 2 diabetes (well controlled). What should you write in your consultation note about Charlie’s perioperative risks, and what interventions should you institute—or recommend—to mitigate his risk?
A preoperative consult, a service that family physicians are well positioned to provide, requires a thorough and systematic approach. But because of time pressures—as well as a dearth of perioperative templates, guidelines, and checklists—a cursory history and physical exam often takes the place of a comprehensive evaluation.
A thorough medical history is the most valuable tool of a physician doing a preop consult, but a comprehensive evaluation also involves the assessment of perioperative risk factors, ancillary tests to consider, and interventions to recommend to mitigate risks. Although various published guidelines address specific systems, there are few places where family physicians can find a complete toolkit. The text and tables that follow, which form the core of a comprehensive resource initially compiled to help our residents conduct clear and effective preoperative consults, will help you safeguard your patients.
A system-by-system review starts with the heart
The vast majority of perioperative problems fall into a handful of categories: cardiac, pulmonary, renal, infectious, and hematologic complications (TABLE 1). When a surgeon requests a preoperative evaluation, however, the patient’s cardiac status is generally the primary concern. This is also the portion of the preop consult with the most formally structured guidelines; those issued by the American College of Cardiology and American Heart Association (ACC/AHA) are the most widely used.1 Initially based primarily on expert opinion, the ACC/AHA guidelines are increasingly evidence-based (http://circ.ahajournals.org/cgi/reprint/CIRCULATIONAHA.109.192690).1,2 These guidelines address the evaluation of patients for noncardiac surgery. Both cardiac surgery and emergent operations are beyond the scope of the guidelines, and are not addressed here.
Patients with unstable coronary syndromes—eg, unstable angina or myocardial infarction (MI) within the past 30 days, decompensated heart failure (HF), significant arrhythmias, or severe valvular disease—face an increased risk of perioperative morbidity and mortality. To reduce the risk, such patients require optimization of the underlying condition before undergoing elective surgery.1
Stable ischemic heart disease, compensated HF, diabetes, chronic renal failure/insufficiency (CRF), cerebrovascular disease, and poor functional capacity (defined as <4 metabolic equivalents [METS]) in an asymptomatic patient also increase the risk of complications, but to a lesser degree. If a patient has coronary artery disease, evidence of ischemia on preoperative testing, or more than 1 of these clinical risk factors, surgery may proceed. Keep in mind, though, that the ACC/AHA guidelines suggest that the use of a beta-blocker, titrated to control heart rate and blood pressure, is reasonable in intermediate- or high-risk procedures (TABLE 1).1,3,4
Is additional cardiac testing necessary? Whether you’re assessing for cardiac status or other risks, for that matter, evidence supports the use of ancillary testing in only a small minority of surgical patients. A general rule of thumb—regardless of the system you’re assessing—is to consider adjunctive testing only if the outcome has the potential to alter patient management. Thus, exercise stress testing or resting electrocardiography (EKG), among other tests, may be considered on an individual basis (TABLE 2), but studies have failed to demonstrate improved outcomes with added testing of cardiac status on a routine basis.5,6
Evidence is insufficient to make a firm recommendation regarding additional cardiac testing, even for patients with more than 3 clinical risk factors. Nonetheless, the ACC/AHA guidelines favor the use of adjunctive testing in such cases, especially for patients who are candidates for high-risk procedures, such as vascular surgery.1
What’s the local standard of care? Studies to determine when further testing is beneficial and which tests would benefit which patients are ongoing. In the absence of definitive findings, it behooves primary care physicians to familiarize themselves with the practices and preferences of the cardiologists and anesthesiologists at the facility where the surgery will be performed and to follow the local standard of care.