2% propofol for sedation in the intensive care unit. A feasibility study.

A 2% solution of propofol has been compared with the 1% formulation for sedation in patients whose lungs were being mechanically ventilated in an intensive care unit following coronary artery bypass surgery. There were no significant differences in the amount of propofol used in the two groups, the rate of propofol infusion or the number of changes made to the infusion rate to maintain the desired level of sedation. Recovery times and times to tracheal extubation were similar. The mean heart rates of those receiving 2% propofol were significantly higher throughout the period of the study for no apparent reason. Propofol 2% was found to be safe, easy to administer and a practical alternative to the 1% solution for sedating cardiac surgical patients.

Ketorolac for postoperative analgesia in elderly patients.

Ketorolac was compared with papaveretum followed by paracetamol plus dextropropoxyphene orally, for postoperative pain relief in elderly orthopaedic patients. Seventy-two patients over the age of 65 years were entered into a double-blind, randomised trial. Pain and pain relief were recorded during an intramuscular and an oral phase, lasting up to 8 days, and a global assessment was made at the end of the study. No difference was demonstrated between the two treatment groups. The incidence of side effects was similar in both groups. It was concluded that ketorolac could provide pain relief equivalent to papaveretum for many patients.

The Humphrey ADE system: evaluation in paediatric use.

The Humphrey ADE single lever parallel form breathing system was evaluated in 17 children whose lungs were ventilated mechanically, mean age 28 (range 9-58) months, weight 13.3 (8.3-18.0) kg and in 10 spontaneously breathing children, age 50.7 (18-99) months and weight 17.5 (10.9-24.3) kg. During controlled ventilation in the E mode, the ADE behaved in a manner similar to the Jackson-Rees modification of Ayre's T-piece with the fresh gas flows (FGF) set either according to weight or at a standard 3 litre min-1. After 5 min hand ventilation in the A mode with FGF 3 litre min-1 the mean end-tidal partial pressure of carbon dioxide was 5.3 (SD 0.8) kPa (range 4.1-7.7 kPa). Whilst breathing spontaneously in the A mode, no patient experienced rebreathing at FGF 3 litre min-1; rebreathing started at 124 (31.6) ml kg-1 min-1. The ADE circuit performed satisfactorily in all three modes. During controlled ventilation in the E mode, FGF should be adjusted according to the standard formulae recommended for the T-piece circuit. During hand ventilation in the A mode, an FGF greater than 3 litre min-1 should be used.

Propofol for induction and maintenance of anaesthesia at caesarean section. A comparison with thiopentone/enflurane.

A propofol infusion regimen and a standard general anaesthetic were compared in 40 Chinese women undergoing elective Caesarean section. Twenty patients received propofol 2 mg/kg for induction of anaesthesia followed by propofol 6 mg/kg/hour, while 20 patients received thiopentone 4 mg/kg with enflurane 1% for maintenance of anaesthesia. All patients were given atracurium and their lungs ventilated with nitrous oxide 50% in oxygen until delivery of the neonate. The hypertensive response after intubation was of shorter duration in the propofol group compared with the thiopentone group. Induction to delivery times ranged from 5 to 14 minutes and neonates from both groups had similar and satisfactory Apgar scores. Neurologic and Adaptive Capacity Scores and umbilical cord blood gas analysis. However, a prolonged propofol infusion time before delivery may cause lower Neurologic and Adaptive Capacity Scores. There were no differences in maternal recovery times or psychomotor performance.

Effect of oral omeprazole on intragastric pH and volume in women undergoing elective caesarean section.

We have studied in obstetric patients the efficacy of omeprazole in increasing intragastric pH to more than 2.5 and reducing volume to less than 25 ml. Omeprazole 40 mg was given orally the night before and again on the morning of surgery to 30 Asian women scheduled to undergo elective Caesarean section. After induction of anaesthesia, a gastric tube was inserted and intragastric contents aspirated. Volume and pH were recorded and measurements were repeated on completion of surgery. The median (range) volume was 2 (1-13) ml before surgery and 4 (0-14) ml at the end of surgery. There was insufficient volume to measure pH in all patients. The median (range) pH was 6.7 (4.6-7.4) before surgery in 20 patients and 6.6 (4.6-7.8) at the end of surgery in 28 patients. No adverse drug reactions were noted in mothers or neonates. Omeprazole 40 mg orally twice before elective Caesarean section appeared to be effective in reducing intragastric volume and acidity to acceptable values.

A comparison of the effects of omeprazole and ranitidine on gastric secretion in women undergoing elective caesarean section.

This study compares the efficacy of omeprazole and ranitidine at reducing gastric secretion in obstetric patients. Sixty-five women scheduled to undergo elective Caesarean section under general anaesthesia were randomly allocated to receive either omeprazole 40 mg or ranitidine 150 mg orally at 2200 hours the night before and at 0600 hours on the morning of surgery. Intragastric pH and volume were measured immediately after induction of anaesthesia and on completion of surgery. All patients had gastric aspirates less than 25 ml. None of the omeprazole group had an aspirate of pH less than 3.5. Six patients (19%) in the ranitidine group had aspirates of pH less than 3.5, a significant difference from the omeprazole group (p less than 0.05). Of these six, two (6%) had aspirates of pH less than 2.5. Hence this study showed that omeprazole was more effective and consistent than ranitidine at maintaining gastric pH greater than 3.5.

Subarachnoid block with hyperbaric lignocaine. A comparison with hyperbaric bupivacaine.

A double-blind study was carried out in 20 patients to compare 5% hyperbaric lignocaine and 0.5% hyperbaric bupivacaine for subarachnoid block. The injections were made in the lateral position and the patients turned supine immediately. The onset, extent and duration of sensory and motor blockade, the quality of anaesthesia, cardiovascular effects and the frequency of side effects were studied. Cephalad spread of analgesia was high (T4-5) with both solutions. Bupivacaine produced a longer duration of action in the lumbar and sacral segments but the duration in the thoracic segments was similar. There was a considerable degree of hypotension in both groups but this responded readily to ephedrine. Hyperbaric lignocaine is an alternative to hyperbaric bupivacaine and its shorter duration of action in the lumbar and sacral segments is advantageous when a fast recovery is desirable.