The aging process: anesthetic implications.

Recent improvement in our understanding of the physiology and pharmacology of aging has occurred in large part because investigators have been able to separate the effects of aging from the consequences of age-related disease. As a group, elderly patients are at increased risk of perioperative morbidity and mortality because of the high incidence of coexisting age-related disease. Even in the absence of chronic disease, organ function remains adequate to meet the basal metabolic requirements of older adults, but the functional reserve and maximal capacity of all major organ systems are significantly reduced and may not meet the increased demands associated with acute illness surgery. Increased rate and severity of perioperative complications may specifically reflect decreased autonomic homeostasis, impaired immune functions, and reduced aerobic capacity to tolerate or compensate for imposed pathology or surgical stress. Age-related chronic disease and, to a lesser extent, progressive erosion of functional capacity explain the increase in perioperative complications seen in an elderly surgical patient population. Therefore, optimal anesthetic management of elderly patients requires adequate diagnosis and treatment of concurrent diseases, meticulous attention to the details of preparation and positioning, and use of monitoring techniques that permit adjustments of drug dosage appropriate for their altered requirements for anesthetic and adjuvant drugs.