CPAP with air and oxygen to non-ventilated lung improves oxygenation during one lung anesthesia

ABSTRACT

Ten adult patients undergoing one lung ventilation for elective thoracotomy were selected. All these patients failed to maintain oxygen saturation [SaO[2]] > 90% despite administration of 100% oxygen to the non-ventilated lung [NVL]. These patients were studied for the efficacy of continuous positive airway pressure [CPAP] of the NVL using air and oxygen combination [FiO20.5] employing a variable FiO2CPAP system. It was observed that application of CPAP [5-10 cm H2O] with a mixture of air and oxygen to the NVL increased the SaO2 > 90% in all these patients. This could be attributed to nitrogen in air which prevented absorption atelectasis in the NVL. This produced a better ventilation/perfusion ratio and hence the increased oxygen saturation