Pericardial fluid gas analysis in hemorrhagic pericardial tamponade.

Nine patients with hemorrhagic pericardial tamponade were studied to determine the localizing value of gas analysis of pericardial fluid in therapeutic pericardiocentesis. The aspirate and the central venous blood was analyzed simultaneously for partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), and hematocrit at the time of pericardiocentesis. In all 9 patients the difference in hematocrit between the pericardial fluid and the central venous blood was not significant. The PCO2 of pericardial fluid was significantly higher than that of central venous blood (p less than 0.025). The PO2 of pericardial fluid was consistently and significantly lower than that of central venous blood (p less than 0.005). We conclude that in patients with hemorrhagic pericardial tamponade, the simultaneous measurement of PO2 and PCO2 of central venous blood and pericardial fluid is a useful rapid bedside method to confirm the site of aspiration during pericardiocentesis. The PO2 determination is statistically the best discriminator between the two fluids in this setting.