Predicting arterial oxygenation during one-lung ventilation with continuous positive airway pressure to the...

Forty patients undergoing elective thoracotomy were studied to assess the possibility of predicting PaO2 during one-lung ventilation (OLV) when continuous positive airway pressure (CPAP) was applied to the nondependent lung. The first 20 patients were studied retrospectively and the three most significant independent variables that correlated with PaO2 during OLV with CPAP were: side of operation (P = 0.04), FEV1/FVC ratio (P = 0.01), and the intraoperative PaO2 during two-lung ventilation (P = 0.0002). By the method of multiple linear regression, these three variables were used to construct a predictive equation for PaO2 during OLV with CPAP. The second 20 patients were studied prospectively and the predicted PaO2 correlated significantly with the observed PaO2 during OLV with CPAP (r = 0.86, P less than 0.001). Therefore, it is concluded that the PaO2 during OLV with CPAP can be predicted using routinely available data.