The recovery of cognitive function after remifentanil-nitrous oxide anesthesia is faster than after an isoflurane-nitrous oxide-fentanyl combination in elderly patients.
We tested the hypothesis that remifentanil-nitrous oxide (N(2)O) anesthesia shortens postoperative emergence and recovery compared with an isoflurane-N(2)O-fentanyl combination in elderly patients undergoing spinal surgery. A total of 60 patients (>65 yr old) were randomly assigned to one of two groups for maintenance of anesthesia. After the induction with 3.6 +/- 1.2 mg/kg IV thiopental and endotracheal intubation facilitated with 1.4 +/- 0.5 mg/kg succinylcholine, patients were maintained with either 0.5%-1.5% isoflurane, 70% N(2)O, and up to 7 microg/kg fentanyl (iso/fent group) or 48 +/- 11 microg/kg remifentanil and 70% N(2)O (remi group). A mini-mental status examination was used to assess cognitive ability preoperatively, at 15, 30, and 60 min after arrival at the postanesthesia care unit and again 12-24 h postoperatively. The time from the conclusion of anesthesia to spontaneous respiration was similar in both groups. Times to eye opening (4.8 +/- 2.6 vs 2.3 +/- 1.1 min), extubation (6.8 +/- 3.8 vs 3.2 +/- 2.1 min), and verbalization (9.9 +/- 6.2 vs 3.9 +/- 2.6 min) were significantly shorter for the remi group (P < 0.05). Postoperative mini-mental status examination scores were significantly lower in the iso/fent group at 15 (16.3 +/- 5.8 vs 23. 7 +/- 3.3), 30 (20.2 +/- 5.2 vs 26.3 +/- 2.7), and 60 min (23.5 +/- 4.4 vs 27.5 +/- 2.0) (P < 0.001); however, the scores equalized after 12 h. Requirements for postoperative analgesics were similar in the two groups. More patients in the remi group were treated with antiemetics (21 vs 7, P = 0.06). Use of remifentanil-N(2)O for maintenance did not shorten the overall length of stay in the postanesthesia care unit; a stay is often related to multiple administrative issues, rather than cognitive recovery.


CONCLUSIONS
Maintenance of anesthesia with remifentanil-nitrous oxide (N(2)O), compared with isoflurane-N(2)O-fentanyl, can safely shorten postoperative recovery of cognitive function in a geriatric population. Earlier recovery may facilitate postoperative neurological assessment. Use of remifentanil-N(2)O for maintenance did not shorten the overall length of stay in the postanesthesia care unit, a stay often related to multiple administrative issues, rather than cognitive recovery.
Bekker
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Department of Anesthesiology, New York University Medical Center, New York 10016, USA. abekker@anes.nyu.edu
Berklayd
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Osborn
I
I
Bloom
M
M
Yarmush
J
J
Turndorf
H
H
D000368:Aged; D000762:Anesthesia Recovery Period; D019162:Anesthetics, Combined; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D003071:Cognition; D004311:Double-Blind Method; D005260:Female; D005283:Fentanyl; D006801:Humans; D007530:Isoflurane; D008297:Male; D009609:Nitrous Oxide; D010880:Piperidines; D020250:Postoperative Nausea and Vomiting; D000077208:Remifentanil; D016037:Single-Blind Method
D019162:Anesthetics, Combined; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D010880:Piperidines; D007530:Isoflurane; D009609:Nitrous Oxide; D000077208:Remifentanil; D005283:Fentanyl