Small bowel and liver tissue pO2 and pCO2 during hypovolaemic shock and intravenous vasopressin infusion.

Ten piglets were bled to a mean BP of 60 mm Hg, after which vasopressin was infused for 30 minutes (2.75 mU/kg/min.). Twenty minutes after completion of the vasopressin infusion, the shed blood was retransfused. Small bowel and liver tissue pO2 and pCO2 were continuously monitored. Systemic arterial and portal blood gas analyses and plasma lactate were studied every 30 minutes. Tissue pO2 in both the small bowel and the liver decreased significantly during hypovolaemic shock; a further non-significant decline was noted during vasopressin infusion. Small bowel pCO2 increased, but liver pCO2 remained unchanged. Plasma lactate increased significantly during hypovolaemia, and vasopressin caused a further increase to a level three times the rest period level. These findings indicate that vasopressin infused during hypovolaemia may increase the risk of hypoxic intestinal lesions and impair liver function.