Canadian journal of anaesthesia = Journal canadien d'anesthésie
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A case is described of complete heart block during spinal anaesthesia for Caesarean section in a fit 23 yr-old-woman. This developed shortly after the institution of the block, with the height of the block below T5 and in the absence of hypotension. ⋯ A Wenckebach block persisted for a short period postoperatively. The importance of instituting monitoring before the beginning of anaesthesia and the immediate availability of atropine and alpha-agonists before the initiation of spinal anaesthesia is stressed.
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Although pressure controlled-inverse ratio ventilation (PC-IRV) has been used successfully in the treatment of respiratory failure, it has not been applied to the treatment of respiratory dysfunction during anaesthesia. With PC-IRV the inspiratory wave form is fundamentally altered so that inspiratory time is prolonged (inverse I:E), inspiratory flow rate is low, and the peak inspiratory pressure is limited. Positive end-expiratory pressure (PEEP) can be applied and the mean airway pressure is higher than with conventional ventilation. ⋯ There were significant increases of (A-a) DO2 at 30 and 60 min (41 and 43%). These changes were less than those reported in a previous study using conventional tidal volume ventilation (7.5 ml.kg-1) and were similar to those in patients whose lungs were ventilated with high tidal volumes (12.7 ml.kg-1). Thus, in this clinical model of compromised gas exchange, arterial oxygenation was better with PC-IRV than with conventional ventilation, but not better than with large tidal volume ventilation.
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Inadequate tissue oxygen uptake autoregulation has been reported during the first hours after extracorporeal circulation for cardiac surgery. In the present study, we examined whether a dependence of oxygen consumption (VO2) on oxygen delivery (DO2) can be detected 24 hr after cardiac surgery using two different vasodilating agents. Cardiac output in triplicate was measured by thermodilution. ⋯ Phentolamine did not alter skin microvascular blood flow, whereas prostacyclin increased skin microvascular blood flow by 33 +/- 3%. The results of the present study demonstrate a supply-dependency of VO2 in clinically stable patients 24 hr after cardiac surgery, suggesting the presence of an inadequate tissue O2 uptake autoregulation. The type of the vasodilator used to increase DO2 seems to play an important role in detecting such a supply-dependency of VO2, as well as changes of skin blood flow.
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To investigate the role of anaesthetic management in early extubation of the trachea in children after closure of a secundum-type atrial septal defect (ASD II), a retrospective chart review for a two-year period was performed. We identified 36 children who underwent surgical repair of an isolated ASD II. In 19 children (53%) the tracheas were extubated in the operating room immediately after surgery and in 17 patients (47%) the tracheas remained intubated and the lungs were ventilated in the Intensive Care Unit. ⋯ Those children in the extubated group had a lower hourly requirement for morphine by infusion (13.6 +/- 5.7 vs 18.2 +/- 5.4 micrograms.kg-1.hr-1) and a shorter stay (20.5 +/- 3.7 versus 29.0 +/- 11.2 hr) in the Intensive Care Unit. Re-intubation of the trachea was not required in any of the children and no deaths occurred. Early extubation after ASD II repair is safe and, given the results of this study, may offer certain advantages over prolonged intubation and ventilation in these children.