Anaesthesia and intensive care
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Anaesth Intensive Care · Jul 2022
Randomized Controlled TrialEffects of an open lung ventilatory strategy on lung gas exchange during laparoscopic surgery.
In general anaesthesia, early collapse of poorly ventilated lung segments with low alveolar ventilation-perfusion ratios occurs and may lead to postoperative pulmonary complications after abdominal surgery. An 'open lung' ventilation strategy involves lung recruitment followed by 'individualised' positive end-expiratory pressure titrated to maintain recruitment of low alveolar ventilation-perfusion ratio lung segments. There are limited data in laparoscopic surgery on the effects of this on pulmonary gas exchange. ⋯ The sevoflurane arterial/alveolar partial pressure ratio and alveolar deadspace fraction were unchanged from baseline and remained similar between groups (mean (standard deviation) control group = 0.754 (0.086) versus intervention group = 0.785 (0.099), P = 0.319), while the arterial oxygen partial pressure/fractional inspired oxygen concentration ratio was significantly higher in the intervention group at the second timepoint (control group median (interquartile range) 288 (234-372) versus 376 (297-470) mmHg in the intervention group, P = 0.011). There was no difference between groups in the sevoflurane consumption rate. The efficiency of sevoflurane uptake is not improved by open lung ventilation in laparoscopy, despite improved arterial oxygenation associated with effective and sustained recruitment of low alveolar ventilation-perfusion ratio lung segments.