SELECTIVE LUNG VENTILATION DURING THORACOSCOPY - EFFECTS OF INSUFFLATION ON HEMODYNAMICS

Background. Positive-pressure insufflation during thoracoscopy has bee n advocated by some authors to facilitate exposure of the intrathoraci c structures by expediting collapse of the lung. We hypothesized that insufflation during thoracoscopy may result in hemodynamic compromise despite selective lung ventilation. Methods. After placement of invasi ve monitoring lines, six adult swine underwent selective lung ventilat ion and thoracoscopy. Baseline measurements of hemodynamic indices wer e taken before selective lung ventilation. The right lung then was col lapsed; data were obtained at insufflation pressures up to 10 mm Hg an d were compared with baseline values using Student's t test. Results. Cardiac index, mean arterial pressure, and left ventricular stroke wor k index decreased, whereas pulmonary artery and central venous pressur es increased (p < 0.05) at insufflation pressures of 5 mm Hg and great er. Conclusions. Positive-pressure insufflation during thoracoscopy re sulted in significant hemodynamic compromise despite the use of select ive lung ventilation. Conversion to thoracotomy may be an alternative if positive-pressure insufflation is necessary to perform the thoracos copic procedure.