Overview of anesthesia for primary care physicians.

Primary care physicians are frequently asked to evaluate patients before elective surgery. Familiarity with anesthetic technique and physiologic processes can help primary care physicians identify risk factors for perioperative complications, optimize patient care, and enhance communication with surgeons and anesthesiologists. To this end, we review the physiologic processes accompanying tracheal intubation and general and regional anesthesia. There is no convincing evidence that regional anesthesia is safer than general anesthesia. In addition to replacing fluid losses from the surgical field and insensible losses, intraoperative fluid administration may attenuate the cardiovascular and renal effects of anesthesia. Therefore, recommendations to limit fluids should be made with caution and should be tempered with an understanding of intraoperative fluid requirements. An understanding of the physiologic processes of anesthesia, combined with preoperative risk stratification strategies, will enhance a primary care physician's ability to provide meaningful preoperative evaluations.

Preoperative cardiac evaluation for elective noncardiac surgery.

We reviewed the approach to preoperative cardiac risk assessment, incorporating new information regarding the pathophysiologic features of perioperative myocardial ischemia and recent clinical trials. Relevant articles were identified from a MEDLINE search, followed by bibliography review of the articles identified. The multifactorial risk indexes are valuable in stratifying risks among unselected patients undergoing noncardiac surgery, but they underestimate the risks in selected groups, particularly patients with peripheral vascular disease. The preoperative evaluation of patients with coronary artery disease and risk reduction strategies for high-risk patients are considered. There are no prospective randomized clinical data comparing preoperative revascularization to intensive medical therapy and clinical decisions must be individualized. Risks particular to patients with congestive heart failure and valvular heart disease are also reviewed. Patients with congestive heart failure can undergo noncardiac surgery safely, if their cardiac disease is well-compensated. Patients with aortic stenosis have high risks, and management strategies include valve replacement, aortic valvuloplasty, and aggressive medical treatment. These modalities have not been compared prospectively, and clinical decisions must be individualized. Preoperative arrhythmias are important risk factors, although they appear to confer risk only when due to underlying heart disease. A thorough, targeted history and physical examination supplemented with judicious laboratory studies are usually sufficient to assess a patient's risk for upcoming noncardiac surgery. The clinical history should identify risk factors that predict cardiac complications, and special attention should be given to those risk factors that can be modified before surgery. New developments in perioperative medicine will likely lead to postoperative interventions to reduce silent myocardial ischemia and clinical complications.