The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Comparative Study Clinical Trial
Comparison of the effects of intravenous almitrine and positive end-expiratory pressure on pulmonary gas exchange in adult respiratory distress syndrome.
The effects of almitrine on pulmonary gas exchange and haemodynamics were compared to those of positive end-expiratory pressure (PEEP) in 10 patients with a severe adult respiratory distress syndrome (ARDS) who required continuous mechanical ventilation. Haemodynamic and gas exchange measurements were made before and after 30 min of PEEP at a level of 10 cmH2O, then 30 min later, before and at the end of the intravenous infusion of almitrine at a dose of 0.25 mg.kg-1 in 30 min. There was no significant difference between baseline gas exchange and haemodynamic parameters. ⋯ Neither PEEP nor almitrine caused a significant change in arterial carbon dioxide tension (PaCO2). The haemodynamic parameters did not change significantly with almitrine, whereas mean systemic arterial pressure decreased from 85.4 to 81.1 mmHg (p less than 0.05) with PEEP. These results are consistent with the hypothesis that both treatments improve ventilation/perfusion (VA/Q) distributions, by an increase in functional residual capacity in the case of PEEP and a redistribution of pulmonary perfusion in the case of almitrine.
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The aim of this study was to measure, in 11 patients with healthy lungs, active inspiratory impedance during anaesthesia. In addition, we recorded changes in inspiratory occlusion pressure at 100 ms (P0.1) and ventilatory pattern while awake and during anaesthesia with a mean inspiratory fraction (FI) of 0.017 halothane in O2. The total active inspiratory resistance and elastance values were 5.4 +/- 3.3 hPa.l.1.s and 29.9 +/- 6.2 hPa.l.1, respectively. ⋯ Respiratory frequency rose significantly from 12.2 +/- 1.5 (mean +/- SD) to 24.6 +/- 4.6 cycles.min-1, while tidal volume and inspiratory duty cycle lowered significantly from 0.599 +/- 0.195 l and 0.44 +/- 0.04 to 0.372 +/- 0.088 l (p less than 0.001) and 0.40 +/- 0.04 (p less than 0.05), respectively. Minute ventilation (VE) and VT/TI did not change significantly. During halothane anaesthesia with an FI:0.017, the increase in neuromuscular respiratory output appears to compensate for the increased mechanical load, thus resulting in maintenance of VE at levels similar to those of an awake state.