Effect of Unilateral Lung Collapse and One-Lung Ventilation on Pulmonary Hemodynamics and Shunt Ratio in Dogs / 대한마취과학회지

ABSTRACT

One-lung ventilation (anesthesia) has been indicated for certain intrathoracic surgery. However the recommended oxygen concentrations and ventilatory patterns have been variously reported. To clarify this, the author has investigate the effect of left lung collapse and right lung ventilation with relatively large, constant tidal volume of 100% oxygen on pulmonary homodyamic and shunt ratio in 10 mongrel dogs with their left main bronchi ligated and cut following thoracotomy under Pentothal anesthesia. The results are as follows 1) Heart rate, mean arterial pressure, central venous pressure, and pulmonary capillary wedge pressure did not change significantly. 2) Mean pulmonary artery pressure and pulmonary vascular resistance increased significantly during one-lung ventilation. 3) Cardiac output decreased slightly, and alveolar-arterial oxygen tension difference and pulmonary shunt ratio increased significantly. However arterial oxygen and carbon dioxide tensions remained in the normal range. It is concluded that to maintain noramil arterial oxygen and carbon dioxide tensions during one-lung ventilation, it is mandatory to ventilate with relatively large, constant tidal volume of 100% oxygen and all measures and precautions should be exercised to maintain normal cardiac output.