British journal of anaesthesia
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Clinical Trial
Accuracy and clinical performance of a continuous intra-arterial blood-gas monitoring system during thoracoscopic surgery.
Accuracy and performance of the only currently available intra-arterial blood-gas monitoring system (Paratrend 7, PT7) were assessed in 23 patients during thoracoscopic surgery using one-lung ventilation. Over a wide range of values for arterial PO2 (6.1-61.1 kPa), PCO2 (4.1-9.5 kPa) and pH (7.19-7.50), 138 arterial blood-gas values obtained by PT7 were compared with corresponding in vitro laboratory blood-gas measurements. ⋯ Also, the bias for sequential changes between two, consecutive times was not significantly different from the ideal value of 0. We conclude that the PT7 is helpful in monitoring patients during thoracoscopy.
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In an open study we have investigated the efficacy of 20 ml of 0.75% ropivacaine (7.5 mg ml-1) to provide extradural anaesthesia for elective Caesarean section. Plasma concentrations (total and free) were estimated in the mother and neonate. ⋯ Plasma concentrations of ropivacaine in the mother and neonate were within safe limits and consistent with previous studies. Two mothers received accidental i.v. injections of ropivacaine 75 mg and 150 mg, respectively, without serious adverse effects.
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We have studied midlatency auditory evoked potentials (MLAEP) and motor signs of wakefulness during anaesthesia with midazolam in 10 patients undergoing elective laparotomy under continuous extradural analgesia. Anaesthesia was induced with midazolam 0.3 mg kg-1 and maintained with midazolam 0.3-0.9 mg kg-1 h-1. Motor signs of wakefulness were documented as spontaneous movements and movements after simple commands (open eyes or move arms). ⋯ Latencies of the MLAEP peaks Pa, Nb and P1 increased slightly during anaesthesia. Amplitudes for Na/Pa, Pa/Nb and Nb/P1 did not change significantly. The high incidence of motor signs of wakefulness associated with preserved MLAEP indicated a high level of cortical neural activity and none of the MLAEP variables predicted movement during anaesthesia with midazolam.
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Randomized Controlled Trial Clinical Trial
Administration of magnesium sulphate before rocuronium: effects on speed of onset and duration of neuromuscular block.
The speeds of onset of pancuronium, atracurium and vecuronium are increased by prior administration of magnesium sulphate. A prospective, randomized, double-blind, controlled, clinical study was performed to examine the effects of prior i.v. administration of magnesium sulphate 60 mg kg-1 on the neuromuscular blocking effects of rocuronium 0.6 mg kg-1 during isoflurane anaesthesia. ⋯ Administration of magnesium sulphate was not associated with adverse haemodynamic effects. Prior administration of magnesium sulphate, under the study conditions described, prolonged rocuronium-induced neuromuscular block but did not increase speed of onset.