We have compared the efficacy of ondansetron with droperidol and saline in the prevention of postoperative nausea and vomiting (PONV) in 120 ASA I and II patients undergoing hip and knee replacements and femoral resections. They received a standardized combined extradural and general anaesthetic and at the end of surgery were allocated randomly to receive droperidol 1.25 mg, ondansetron 4 mg or 0.9% saline in a 25-ml bag. An extradural mixture containing 0.5% plain bupivacaine 10 ml, fentanyl 500 micrograms and saline 30 ml was infused and PONV assessed for 24 h. Both ondansetron and droperidol were superior to saline in preventing vomiting (P < 0.01) although there was no significant difference between them. The incidence of vomiting was 17% for ondansetron, 18% for droperidol and 45% for saline. There was no significant difference in the incidence of nausea between the groups. Metoclopramide, the rescue antiemetric, was demanded by 38%, 34% and 17% of patients receiving saline, droperidol and ondansetron, respectively (ondansetron vs droperidol P < 0.05).

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No abstract

We have examined the effects of two different bolus doses of esmolol hydrochloride (Brevibloc) on haemodynamic variables in a placebo-controlled, double-blind, randomized trial. Sixty healthy adult patients undergoing minor orthopaedic surgery were given a standardized general anaesthetic using a laryngeal mask airway. Heart rate (HR), mean arterial pressure (MAP), stroke volume (SV) and cardiac output (Q) were measured (the latter two by Doppler ultrasonography) every 1 min for 5 min after injection of either placebo or esmolol 100 mg or 200 mg. HR, MAP, SV and Q decreased significantly (P < 0.05) for both esmolol groups compared with placebo and, except for MAP, esmolol 200 mg had a greater effect than esmolol 100 mg (P < 0.05). Depression was maximal at 2 min after which recovery was observed but was still incomplete at 5 min.

We studied the effects of supplementing nitrous oxide-oxygen anaesthesia with halothane (1 MAC end-tidal concentration) on the motor evoked potential recorded in the extradural space of eight patients before corrective surgery for idiopathic adolescent scoliosis. The motor cortex was stimulated electrically through the scalp. An additional eight patients in whom anaesthesia was supplemented with an infusion of propofol acted as a control group. Halothane had no significant effect on the amplitude or latency of the motor evoked potential. We conclude that halothane is unlikely to alter the interpretation of motor evoked potentials recorded extradurally during scoliosis surgery.