Sufentanil and nitrous oxide anaesthesia for cardiac surgery.

We have investigated the use of sufentanil 3.75-15 micrograms kg-1 by supplementing anaesthesia with nitrous oxide and midazolam. Thirty patients with ejection fractions exceeding 30% were studied while undergoing scheduled coronary artery vein graft surgery. Even in the lowest dose group (3.75 micrograms kg-1), haemodynamic responses to surgical and anaesthetic stimuli were sufficiently obtunded that no patient exhibited an increase in heart rate or systolic arterial pressure greater than 20% of the control value. Marked hypotension occurred in some patients during unstimulated periods. Such periods of hypotension were associated with equally marked decreases in systemic vascular resistance. The mean recovery times to spontaneous ventilation after the end of surgery ranged from 6 to 12 h. This is longer than would be expected from other studies using a similar dose of sufentanil. This may be related to the use of benzodiazepines during anaesthesia and to their use after surgery in those patients who became restless.

Comparison of the haemodynamic effects of intermittent positive pressure ventilation with high frequency jet ventilation. Studies following valvular heart surgery.

The cardiorespiratory effects of intermittent positive pressure ventilation and high frequency jet ventilation with and without positive end expiratory pressure were compared in patients following valvular heart surgery (mitral and/or aortic). Twenty patients received intermittent positive pressure ventilation and high frequency jet ventilation with 0, 0.5 and 1.0 kPa positive end expiratory pressure. High frequency jet ventilation was well tolerated. The addition of 1.0 kPa positive end expiratory pressure was associated with preservation of the arterial oxygen tension without any increase in shunt or significant adverse haemodynamic effect. The results are discussed and compared with a previous study of high frequency jet ventilation following aortocoronary bypass graft surgery.

Prolonged sedation and paralysis in a pregnant patient. Delivery of an infant with a normal Apgar score.

The spontaneous delivery of an infant with normal Apgar scores following 16 hours of maternal paralysis and sedation with atracurium and Althesin is described. A coincidental complication of subclavian vein thrombosis possibly due to the infusion of Althesin through the central venous catheter is also discussed.

The neuromuscular transmission monitor. A clinical assessment and comparison with a force transducer.

The neuromuscular transmission monitor (NTM) is a new device for measuring neuromuscular transmission during anaesthesia. We have assessed its use in comparison with a force transducer and found for single twitch and train-of-four modes that there was a strong positive correlation between the two methods. This device appears reliable in use and provides a satisfactory alternative to conventional neuromuscular monitoring.

Dose requirements of ICI 35,868 (propofol, 'Diprivan') in a new formulation for induction of anaesthesia.

In order to avoid Cremophor-related reactions and reduce the incidence of pain on injection, diisopropylphenol (ICI 35,868; propofol) has been reformulated as an emulsion. One hundred and fifteen patients received an induction dose of propofol in the new formulation. The dose required to induce anaesthesia in 95% of healthy, unpremedicated patients was 2.5 mg/kg. Induction was associated with a degree of cardiovascular and respiratory depression. There were no adverse reactions although there were a number of minor side-effects. The incidence of pain on injection was low (3%) and the overall quality of induction was assessed as good or adequate in 92% of patients.