Improved postoperative analgesia with isoflurane than with propofol anaesthesia

Purpose: The impact of hypnotic drugs on postoperative analgesia has not been evaluated, We compared the influence of the maintenance of anaesthesia with either propofol or isoflurane on postoperative pain. Methods: Forty ASA 1-2 women. undergoing cosmetic abdominoplasty were randomized to receive either 6-12 mg.kg(-1).hr(-1) propofol iv (P, n = 20) or MAC 1-1.5 isoflurane inhalation (Iso, n = 20). The lungs were ventilated with N2O 60% and O-2 40%, and 1 mu g.kg(-1) fentanyl iv provided intraoperative analgesia. Before surgical closure. 2 g propacetamol iv were administered. Postoperative analgesia was provided after hourly assessment of pain (VAS 0-100 mm), with 10 mg nalbuphine iv if VAS greater than or equal to 50 mm, during the eight hours after surgery. Sedation score (awake 0 to unrousable 4) was also recorded, Analgesia satisfaction score (nil 0 to excellent 4) obtained from the patient on discharge. Results: Sedation scores were similar in both groups except in the first postoperative hour, when it was higher in the Iso group. The VAS at rest (15.4 +/- 18.6 vs 29.7 +/- 19.8 mm, P = 0.0001) and nalbuphine requirements (0.13 +/- 0.35 vs 0.70 +/- 0.80 doses, P = 0.004) were lower in the iso group during the first six hours, although emesis was more frequent than in P (60 vs 25%; P = 0.03), The incidence of analgesia satisfaction score (greater than or equal to 3) was similar between the two groups (P: 95; Iso: 75%). Conclusion: These results suggested that isoflurane anaesthesia provides better analgesia than propofol anaesthesia in the first six hours after abdominoplasty.