RECOGNITION AND MANAGEMENT OF PREOPERATIVE RISK

Internists are frequently asked to do preoperative consultations and to manage perioperative complications. Realistic goals are to identify patient factors that increase the risk of surgery, to quantify this risk in order to make decisions about the appropriateness of and timing of the surgery, to provide recommendations on how to minimize the risk, to identify and manage coexisting medical conditions and their associated medication requirements, to monitor the patient for perioperative problems, and to make recommendations to deal with these problems when they occur. With few exceptions, nonselective imaging and laboratory screening tests have repeatedly been shown to be of little value when the history and physical do not suggest a problem. The risk associated with the planned surgery can be estimated, with the most common serious complications being cardiac events. Updated versions of Goldman's risk indices are particularly helpful for this. Clinical variables are optimally combined with selective stress testing to discern which patients will benefit from preoperative revascularization. This has been studied best in the setting of vascular surgery. A critical guiding principle is that the value of revascularization must be judged in terms of long term gains rather than just immediate perioperative benefit. Other interventions include the selective use of beta blockers, adequate analgesia for all, control of hypertension, and appropriate volume management, especially in the settings of preexisting CHF or valvular disease. It must also be recognized that perioperative ischemia and CHF often present atypically. An approach that combines aspects of both the ACC/AHA and the ACP guidelines seems optimal. A variety of noncardiac issues must also be addressed. Postoperative pulmonary complications are common, especially with preexisting pulmonary disease, thoracic and upper abdominal surgery, and obesity. PFTs and ABGs are indicated in selected patients. Stopping smoking, incentive spirometry, and selective use of bronchodilators and antibiotics are helpful. Patients with rheumatologic diseases have specific concerns based on systemic manifestations of disease including anemia, thrombocytopenia, pulmonary fibrosis, pericarditis, and hypercoagulability; medication effects particularly from steroids and nonsteroidal anti-inflammatory drugs; and specific joint problems including contractures and atlantoaxial joint instability. Diabetes increases the risk of infection and cardiac complications. Prevention of ketoacidosis and glucose control are necessary and can be achieved through a variety of approaches, depending on whether the patient suffers from Type 1 or Type 2 diabetes. The threshold for transfusion has increased in recent years, as has the use of erythropoietin and autologous blood donation. There is no longer an absolute hemoglobin that requires transfusion, although most require transfusion for hemoglobins less than 8 mg/dL, especially in the setting of cardiac disease and bloody surgery. The elderly require surgery at an increased rate and often do not do as well as younger patients. The primary issues are, however, not their age but their increased frequency of underlying disease and diminished reserve. The latter makes them prone to postoperative delirium, sensitivity to medications, and cardiac and pulmonary problems. Despite the many diseases that patients often have and the stresses of surgery itself, modern anesthetic and surgical techniques allow almost all patients to undergo necessary procedures at acceptable risk. The internist plays a critical role in minimizing this risk even further.