We studied 42 patients undergoing oral surgery under local anaesthesia with i.v. sedation, allocated randomly to receive either methohexitone (group M) or propofol (group P) for patient-controlled sedation (PCS). Group M patients self-administered 2.5-mg (0.5 ml) bolus doses of methohexitone and group P, 5-mg (0.5 ml) doses of propofol, without a lockout. The 0.5-ml bolus dose was delivered over 7.2 s for both drugs. The procedure was completed satisfactorily in all patients. Patients in both groups achieved their desired levels of sedation. No patient lost verbal contact. Group M patients had higher heart rates during the procedure. The lowest SpO2 values recorded were 92% and 95% for group P and group M, respectively. Immediately after operation patients in group M reported that they felt more sleepy than those in group P (P < 0.01) but there were no differences at subsequent times. The results of the psychomotor tests were comparable for the two groups after operation, except for the "posting box task" at 15 min after operation when the mean decrement (compared with preoperative performance) was -3% for group P and -13% for group M (P < 0.05). More patients in group P complained of pain in their hand. We conclude that methohexitone is a suitable alternative drug to propofol for PCS.

In this double-blind trial, we observed the effect of intermittent wound infiltration with local anaesthetic plus continuous coeliac plexus blockade on postoperative pain relief, pulmonary function, the neuroendocrine and acute phase protein response following upper abdominal surgery. In Group A (n = 10) patients received bupivacaine intermittently into the wound and continuously into the coeliac plexus following an initial bolus. A total of 862.5 mg of bupivacaine was used over 12 h with no observed toxicity. Group B (n = 10) received equal volumes of saline. Although pain relief was poor in both groups, the bupivacaine group used less morphine postoperatively and had lower pain scores than the saline group 4 h after operation (P less than 0.05). Pulmonary function was significantly reduced in both groups with no statistical difference between the two. Significant reductions in serum glucose and cortisol were achieved (P less than 0.05), suggesting that afferent neural blockade was partially effective in attenuating the neuroendocrine response. However, the postoperative rise in interleukin-6 was not affected by this technique. It is concluded that total afferent neural blockade cannot be achieved with peripheral wound and coeliac plexus administration of relatively large doses of local anaesthetic during upper abdominal surgery.

SummaryThe