Pressure-controlled versus volume-controlled ventilation during one-lung ventilation for thoracic surgery

BACKGROUND: Pressure-controlled ventilation (PCV) has been suggested as a tool to improve oxygenation during one-lung ventilation (OLV) for patients undergoing thoracic surgery. In this study we investigated whether PCV results in improved arterial oxygenation compared with volume-controlled ventilation (VCV) during OLV. METHODS: Fifty-eight patients with good preoperative pulmonary function scheduled for thoracic surgery were prospectively randomized into two groups. Those in group A underwent OLV initially with VCV for 30 min followed by PCV for a similar period of time. Those in group B underwent OLV initially with PCV for 30 min followed by VCV for a similar duration. Airway pressures and arterial blood gases were obtained during OLV at the end of each ventilatory mode. RESULTS: There were no differences during OLV in arterial oxygenation between VCV (Pao(2), 206.1 +/- 62.4 mm Hg) and PCV (Pao(2),202.1 +/- 56.4 mm Hg; P = 0.534). Peak airway pressure was lower with PCV than with VCV (24.43 +/- 3.42 cm H2O vs. 34.16 +/- 5.21 cm H2O; P < 0.001). CONCLUSIONS: The use of PCV during OLV does not lead to improved oxygenation during OLV compared with VCV for patients with good preoperative pulmonary function, but PCV did lead to lower peak air-way pressures. Further study is needed for patients with severe obstructive or restrictive pulmonary disease.