EFFECTS OF CONTINUOUS POSITIVE-PRESSURE VENTILATION ON HEPATIC BLOOD FLOW AND INTRAHEPATIC OXYGEN DELIVERY IN DOGS

Abstract

The effect of mechanical ventilation with PEEP of 0, 10, and 20 cm H2O (continuous positive-pressure ventilation [CPPV]) on hepatic blood flow (HBF) and intrahepatic oxygen delivery was studied in 26 mongrel dogs anesthetized with fentanyl. Hepatic arterial and portal venous blood flow was measured by an electromagnetic flowmeter. CPPV caused a significant decrease in HBF, which was related to the PEEP level. A linear correlation was seen between HBF and cardiac output. Intrahepatic oxygen delivery decreased more than HBF and cardiac output. The reduced oxygen delivery was due mainly to the decrease in portal venous oxygen content.