Canadian Anaesthetists' Society journal
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The effects of anaesthetic agents, per se, on the asphyxiated foetus are difficult to quantitate clinically. Anaesthesia is often necessary in foetal distress, however, to effect a rapid delivery. To investigate the effect of general anaesthetic agents commonly used for Caesarean section we administered these agents to 18 chronically prepared pregnant ewes with asphyxiated foetuses in utero. ⋯ There were no significant differences between Groups B and C in foetal pH, PCO2, or PO2. Two foetuses in the nitrous oxide group died after ten minutes of anesthesia, but the aetiology of the sudden demise is unclear. We conclude that general anaesthesia abolishes the foetal response to umbilical cord occlusion and does not improve foetal oxygenation or acid-base status.
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Randomized Controlled Trial Comparative Study Clinical Trial
Cardiovascular responses to the insertion of nasogastric tubes during general anaesthesia.
Eighty female patients free of cardiovascular disease who were having excision of breast lesions were randomly allocated to one of two groups. In the first group a nasogastric tube was inserted blindly during the surgical procedure, while in the second group the tube was inserted under direct laryngoscopy, using Magill forceps. ⋯ These increases declined during the following 3 minutes. Ventricular extrasystoles (more than 5 during the 3 min following the insertion of the nasogastric tube) occurred only in the group having the nasogastric tube with the aid of laryngoscopy (p less than 0.05).
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Comparative Study Clinical Trial Controlled Clinical Trial
Atracurium for short surgical procedures: a comparison with succinylcholine.
A comparison was made between atracurium and succinylcholine in 40 patients undergoing short gynaecological procedures of 30 minutes or less. Good intubating conditions were produced in 76.7 +/- 39.3 seconds (mean +/- S. D.) with succinylcholine 1 mg . kg-1 and 198 +/- 84 seconds with atracurium 400 micrograms . kg-1. ⋯ However, the onset of action is slow, compared to succinylcholine. Residual neuromuscular block can be antagonised with standard doses of neostigmine, less than 20 minutes after the initial dose of relaxant. Atracurium appears to be a suitable alternative for short procedures where succinylcholine is unsuitable or contraindicated.
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Aspiration around uncuffed endotracheal tubes in paediatric patients is an uncommon event. Uncuffed endotracheal tubes are commonly used in paediatrics even when the risk of gastric aspiration is significant. A case history is presented of an 81/2-year-old who aspirated during a laparotomy for bowel obstruction. ⋯ Uncuffed endotracheal tubes are used because post-intubation stridor is minimized, the lungs are compliant and the funnel-shaped trachea is more likely to secure the airway from aspiration. An uncuffed tube however, does not completely seal the airway, particularly in the presence of an audible "leak." As a result of this case, we now consider the use of a cuffed endotracheal tube in children whenever a 5.5 internal diameter or larger is required. When the risk of pulmonary aspiration is present, the cuff is inflated to reduce the likelihood of contamination of the airway.
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Cardiovascular changes during difficult intubation were studied in 25 patients undergoing open heart surgery. The study was divided into two phases. Phase A from the first laryngoscopy to the fourth unsuccessful one; Phase B from a stabilization period until after retrograde intubation was performed. ⋯ There were more lacerated lips and teeth damaged during Phase A. One patient developed a small peritracheal haematoma after the retrograde intubation, for which no treatment was required. This technique is safe and produces minimal cardiovascular changes for difficult intubation in patients undergoing open heart surgery.