The effects of physostigmine on recovery from general anesthesia in elderly patients.

BACKGROUND: Transient cognitive dysfunction after general anesthesia is a frequent finding among elderly patients. The aim of this study was to evaluate whether the use of physostigmine may enhance recovery from general anesthesia in elderly patients. METHODS: Eighty American Society of Anesthesiologists (ASA) physical status I-III patients aged >65 years old who were scheduled for a laparoscopic cholecystectomy received either 2 mg physostigmine in 250 mL N/S 0.9% (Physo group) or 250 mL N/S 0.9% placebo (Control group) after induction of anesthesia via slow IV infusion over 45 minutes. This experiment was performed as a prospective, randomized, double-blinded study. Patients were assessed for sedation, orientation, ability to sit, and ability to pass the "picking up matches" test at 15 minutes, 8 hours, and 24 hours postoperatively. Patients were also evaluated for pain using the visual analogue scale (VAS) score both at rest and with movement. RESULTS: The time to extubation was significantly shorter in the Physo group than in the control group (8.0±2.7 vs. 9.8±3.6 min, P=0.012). The time required to pass the "picking up matches" test was also shorter for the Physo group at all of the time points postoperatively (15 minutes postoperatively: 18.0±7.1 vs. 24.6±11.6 sec, P=0.003, 8 hours postoperatively: 11.8±3.9 vs. 16.0±6.0 sec, P<0.001, 24 hours postoperatively: 8.8±3.4 vs. 11.2±4.7 sec, P=0.008). Evaluations of patient orientation and sedation were similar between the experimental and control groups. The VAS score and analgesic requirement were decreased in the Physo group compared to the control group during the first postoperative day. The ability to sit after extubation was also increased in the Physo group at both 15 minutes (P=0.001) and 8 hours postoperatively (P<0.001). CONCLUSION: The intraoperative infusion of physostigmine enhances alertness, coordination, manual dexterity and mobilization after general anesthesia in elderly patients, but physostigmine administration does not affect orientation or sedation.