Effect of thoracentesis on arterial oxygen tension.

The acute effects of thoracentesis on arterial oxygenation were observed in 19 studies on 17 patients. Arterial blood samples were obtained prior to, immediately after, and 1 h after thoracentesis. Unpredictable changes in the arterial oxygen tension, ranging from -22 to +19 mm Hg were found immediately following thoracentesis. It was concluded that significant hypoxemia may result from thoracentesis due to aberration of ventilation-perfusion relationships. It is further suggested that oxygen therapy be routinely administered during and immediately after the procedure.