Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Aug 1990
Ventilation-perfusion relationships and atelectasis formation in the supine and lateral positions during conventional mechanical and differential ventilation.
Patients without respiratory symptoms were studied awake and during general anesthesia with mechanical ventilation prior to elective surgery. Ventilation-perfusion (VA/Q) relationships, gas exchange and atelectasis formation were studied during five different conditions: 1) supine, awake; 2) supine during anesthesia with conventional mechanical ventilation (CV); 3) in the left lateral position during CV; 4) as 3) but with 10 cm of positive end-expiratory pressure (PEEP) and 5) as 3) but using differential ventilation with selective PEEP (DV + SPEEP) to the dependent lung. Atelectatic areas and increases of shunt blood flow and blood flow to regions with low VA/Q ratios appeared after induction of anesthesia and CV. ⋯ Perfusion of regions with low VA/Q ratios and venous admixture were then diminished, while PaO2 was slightly increased; shunt blood flow and dead space ventilation were essentially unchanged. During CV + PEEP, there was a decrease in cardiac output, compared to CV in the lateral position. DV + SPEEP was more effective than CV + PEEP in decreasing shunt flow and increasing PaO2 in the lateral position; in addition to this, cardiac output was not affected.
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Acta Anaesthesiol Scand · Aug 1990
Randomized Controlled Trial Clinical TrialThe influence of 10 mg and 20 mg of bambuterol on the duration of succinylcholine-induced neuromuscular blockade.
Bambuterol is an inactive prodrug which is enzymatically cleaved by plasma cholinesterase to yield the active compound, terbutaline. This catalytic process is accompanied by a selective inhibition of plasma-cholinesterase, the enzyme also necessary for the break-down of succinylcholine. We therefore studied the possible effect of bambuterol on succinylcholine-induced neuromuscular blockade in a double-blind fashion in patients undergoing surgery under general anaesthesia. ⋯ Onset time and the durations of action (times to 10%, 25%, 75% and 90% recovery of the first twitch of the train-of four response) were recorded. The mean recovery times were prolonged 30-50% in patients who had received 10 or 20 mg of bambuterol as compared with placebo. It is concluded that a prolonged duration of action of succinylcholine can be expected in patients being treated with bambuterol.