To assess the evolution of the anesthetic workload related to elderly population (> or = 65 yr) at the University Hospital of Geneva, the total number of anesthesia cases, high-risk patients, and emergency procedures, as well as the total duration of anesthesia and incidence of perianesthetic complications, were retrospectively analyzed over 10 yr. The squared correlation coefficient was used to assess the proportion of variance explained by the linear regression of the absolute and the relative number of events over time. More than 165,000 anesthesia procedures were analyzed, and the data were separated into two groups: the younger population (<65 yr) and the elderly population (> or = 65 yr). From 1985 to 1994, the elderly surgical population grew significantly faster (P < 0.001) than the elderly resident population (from 20.3% to 25.1% versus from 12.5% to 13.6%). Half of the increased number of anesthesia cases during this period were administered to elderly patients. The number of high-risk elderly patients increased by 48.3% (P < 0.0001). The number of emergency procedures in elderly patients increased only until 1991, and a significant decrease in the incidence of perianesthetic complications was observed. Because the mean duration of each procedure remained constant, the increased anesthetic workload in our institution was mainly due to increased geriatric surgical activity.
Implications: During a study period of 10 yr, the increased anesthetic workload (defined as the number of anesthesia cases, high-risk patients, emergency procedures, and complication rate) at the University Hospital of Geneva was mainly due to the increased geriatric (patients > or = 65 yr) surgical activity, not to the aging of the resident population.