Recovery and discharge of patients after long propofol infusion vs isoflurane anaesthesia for ambulatory surgery

Fifty unpremedicated patients scheduled for outpatient restorative dentistry and/or oral surgery lasting 2 to 4 h were anaesthetized with either propofol infusion or isoflurane inhalation. Before induction of anaesthesia with propofol (2.5 mg ˙ kg‐1), all patients were given 75 mg of diclofenac and 0.01mg ˙ kg‐1 vecuronium intravenously. Intubation was facilitated with suxamethonium (1.5 mg ˙ kg‐1) and anaesthesia was maintained in random order either with propofol infusion (12 mg ˙ kg‐1 ˙ h‐1 for the first 20 min, 9 mg ˙ kg‐1 ˙ h‐1 for the next 20 min, and 6 mg ˙ kg‐1 ˙ h‐1 for the rest of the anaesthesia) or with isoflurane (inspired concentration 1–2.5%), both with nitrous oxide and oxygen (30%). The patients breathed spontaneously using a non‐rebreathing circuit. Patients given propofol infusion became re‐orientated faster (11.0 ± 5.5 min vs. 16.5 ± 7.5 min; P<0.01) and at 30 min walked along a straight line better (P<0.01). At 60 min, none of the propofol patients displayed an unsteady gait, whereas 11 of the 25 isoflurane patients did (P<0.001). None of the patients receiving propofol had emesis at the clinic, compared with 10 of the 25 patients receiving isoflurane (P<0.001). The overall incidence of emesis was 2 of 25 and 14 of 25 in the propofol and isoflurance groups, respectively (P<0.01). Patients receiving propofol were discharged home earlier than patients receiving isoflurane (80 ± 14 min and 102 ± 32 min, respectively; P<0.01). It is concluded that propofol allows early discharge of patients, even after long anaesthesias.