Physiological features of aging persons.

B etween 1960 and 1994, the population of those 85 years and older in the United States grew 274%. Similarly, the fastest-growing sector of surgical patients older than 65 years is those older than 85 years. These figures are critical because elderly persons have the highest mortality in the adult surgical population (5.8%-6.2% in those 80 years in 500 consecutive patients requiring general or regional anesthesia and 8.4% in those 90 years in 795 in-house operations). Why do elderly persons face such high surgical mortality rates? In addition to a higher incidence and prevalence of disease, elderly persons experience baseline physiological changes associated with senescence. It is vital for the modern surgeon to be aware of the physiological changes associated with aging to minimize morbidity and mortality in the aging surgical population.