British journal of anaesthesia
-
Male Fischer 344 rats were exposed to halothane, enflurane or isoflurane vapour 20 p.p.m., or air, for up to 30 weeks. None of the anaesthetic agents led to hepatocellular necrosis. ⋯ Urinary fluoride excretion was increased during exposure to either enflurane or isoflurane. Using this increase as an index of anaesthetic biotransformation, we found that the extent of biotransformation of isoflurane was only slightly lower than that of enflurane.
-
Comparative Study
Emergency intubation of the trachea facilitated by suxamethonium. Observations in obstetric and general surgical patients.
The relationship between the time of onset of neuromuscular blockade and the time at which laryngoscopy was attempted was studied in patients presenting for emergency obstetric or emergency general surgical procedures. "Train-of-four" stimulation and visual observation of the evoked twitch response in the hand were used as a measure of the degree of neuromuscular blockade. The attendant anaesthetist was unaware of the response to the peripheral nerve stimulator. Intubation preceded complete neuromuscular blockade; in the obstetric patients there was no correlation between the two times. The use of a peripheral nerve stimulator should allow the anaesthetist to perform intubation in emergency situations with a greater degree of safety.
-
Randomized Controlled Trial Clinical Trial
Effect of heat conservation during and after major abdominal surgery on muscle protein breakdown in elderly patients.
Changes in mean body temperature and muscle protein metabolism were studied in elderly patients undergoing large bowel surgery. Two groups were studied: in one, efforts were made to maintain the patients normothermic during and after surgery by warming the fresh gases, the i.v. fluids, by placing warmed cotton padding around the exposed parts of the body and by covering the patients with a metallized plastic sheet in the recovery period. ⋯ The excretion of the amino acid 3-methylhistidine (3-MeH), an indicator of muscle protein breakdown, and urea nitrogen loss were measured in the urine collected the day before, and on the 2nd and 4th postoperative days. Prevention of heat loss during and after surgery caused a significant decrease in muscle protein degradation and nitrogen loss.
-
Comparative Study
Recovery of spontaneous breathing following neuromuscular blockade with atracurium.
Atracurium 0.3 mg kg-1 was given to two groups of patients to compare the recovery of spontaneous breathing with that of peripheral neuromuscular function. Anaesthesia was maintained in one group (n = 6) with an infusion of etomidate (mean flow rate 24 micrograms kg-1 min-1) and in the other group (n = 5) with 0.5% halothane. ⋯ Adequate recovery of respiratory muscle function occurred within 30 min of administration of atracurium at a time when there was less than 25% recovery of the tetanic response of the adductor pollicis muscle. It was concluded that recovery of the muscles of respiration from neuromuscular blockade by atracurium occurred more rapidly than recovery of the muscles of the hand, but an adequate tidal volume in the absence of other clinical signs should not be regarded as a reliable indicator of complete return of neuromuscular function.
-
Pure suxamethonium chloride does not produce in vitro contracture of skeletal muscle from swine which are susceptible to malignant hyperpyrexia (MH), but does induce MH in vivo. It is suggested that suxamethonium chloride induces MH because the fasciculations which it causes lead to an increase in the myoplasmic calcium concentration.