Premedication with piroxicam in patients having dental surgery under general anaesthesia with halothane or isoflurane.

Pain, analgesic requirements, mouth opening and emesis were assessed in 60 patients who received either piroxicam 40 mg or placebo before dental surgery under general anaesthesia which included breathing either halothane or isoflurane. Patients went home on the day after surgery and completed a questionnaire concerning pain and emesis. There were four groups of 15 subjects: piroxicam-halothane, piroxicam-isoflurane, placebo-halothane or placebo-isoflurane. Pain increased at 2 and 4 h and had reduced by 18 h after surgery; there were no significant differences between the groups in pain scores. After operation, fewer patients in the piroxicam-isoflurane group required papaveretum compared with the piroxicam-halothane and placebo-halothane groups. Mouth opening was reduced between 2 and 4 h after surgery, but was less restricted after piroxicam-isoflurane than placebo-halothane. There was no difference between the groups in the incidence of emesis within 18 h of surgery. The postal questionnaire suggested that pain and emesis were reduced significantly during the 3 days after surgery in patients who had received piroxicam before surgery, compared with those who had received placebo.

Effect of passive hyperventilation on seizure duration in patients undergoing electroconvulsive therapy.

The influence of end-expired carbon dioxide concentration (E'CO2) on seizure duration was studied in 30 depressed patients undergoing electroconvulsive therapy (ECT) on three separate consecutive occasions. Unpremedicated patients breathed 100% oxygen before the induction of anaesthesia with methohexitone and the provision of partial neuromuscular blockade with suxamethonium. They then received no further ventilation, 10 breaths, or 20 breaths of hyperventilation with 100% oxygen from a non-rebreathing system with a high fresh gas flow. Transcutaneous oxyhaemoglobin saturation (SaO2) was monitored continuously and E'CO2 was measured before and after the seizure. Observation of an isolated forearm was used to time the seizure duration. SaO2 remained greater than 90% in all patients. Passive hyperventilation with 20 breaths significantly reduced E'CO2 and prolonged seizure duration. E'CO2 before the seizure and change in E'CO2 during the seizure did not correlate significantly with seizure duration.