A study of anesthetic drug utilization in different age groups.

Study Objective: To determine anesthetic drug utilization in different age groups.
Design: Retrospective, automated, intraoperative database study.
Setting: Tertiary care medical center.
Measurements: 30,842 noncardiac general anesthesia case records between January 1991 and July 1997 were studied. We investigated the effect of age on anesthetic requirements for fentanyl (F), midazolam (M), thiopental sodium (T), propofol (P), isoflurane (I), and nitrous oxide (N). Because drugs are not given in isolation we looked at the most common drug combinations, IFNTM, IFNPM, INFT, and PFNM. Regression analyses on log-transformed drug dosages were used to test the significance of age on individual requirements.
Results: In each of the above anesthetic drug combinations, reduced doses of fentanyl, propofol, midazolam, thiopental, and isoflurane were used with increasing age. Fentanyl, propofol, thiopental, and isoflurane showed a 10%, 8%, 6%, and 4% reduction in dose per decade of age, respectively, from age of maximum dose to age 80 years.
Conclusions: In clinical practice, increasing age results in decreased anesthetic drug administration. The mechanism of this observation needs to be determined.