The effect of iloprost on arterial oxygenation during one-lung ventilation

Abstract

Background During one-lung ventilation in patients undergoing thoracic surgery, the persistent flow in the non-ventilated lung increases intrapulmonary shunt and decreases systemic arterial oxygenation. Aims and objectives This study was conducted to evaluate the effects of iloprost on arterial oxygenation during one-lung ventilation in the lateral decubitus position during thoracic surgery. Methods 72 patients undergoing thoracoscopic lobectomy were randomly allocated to three groups: DW (distilled water), IL2.5 (iloprost 2.5mcg), and IL5 (iloprost 5mcg). Study drug was inhaled to ventilated lung for 5 minutes after one-lung ventilation in the lateral decubitus position. Hemodynamic variables, shunt fraction, and arterial oxygenation were obtained at these points: after induction of anesthesia with two-lung ventilation (TLV-i), before treatment with one-lung ventilation in lateral decubitus posisiton (OLV), 10, 20 and 30 min after treatment (OLV+T10, OLV+T20 and OLV+T30), and at the end of surgery with two-lung ventilation in the supine position (TLV-e). Results Hemodynamic variables were comparable between three groups. Shunt fraction was significantly lower in IL5 compared with that in DW and IL2.5 during one-lung ventilation. PaO2 was significantly higher in IL5 compared with that in DW and IL2.5 at 10 (198±78 vs. 146±68, 148±70 mmHg, P Conclusions Inhaled iloprost at 5 mcg improves arterial oxygenation during one-lung ventilation in the lateral decubitus position during thoracic surgery.