POrtal-Systemic Venous Shunts In Hemorrhagic Shock In The Dog And Monkey

Abstract

Irreversible shock is accompanied by gross congestion in the small bowel of the dog but not of the primate. To investigate the possible role of portal-systemic shunts as alternate pathways to drain the splanchnic circulation in the monkey, krypton85 and ascorbic acid were injected into the portal vein. The isotope was monitored by a Geiger-Mueller tube in the expired air; ascorbic acid was detected by a platinum electrode in the right atrium. Appearance times were sensitive to artificial portal-systemic shunt flows of 5 ml./min. Six dogs and 7 macaque monkeys anesthetized with morphine sulfate and nembutal were subjected to a standardized hemorrhagic shock procedure. In the dog and the monkey appearance time was shortened by 51.0 [plus or minus] 8.6% and 62.1 [plus or minus] 9.1% of control respectively with reinfusion of the shed blood. When the portal vein was occluded, the appearance time in the dog was either mostly prolonged or the indicator never appeared. In the monkey, with portal vein occlusion, the appearance time became shortened suggesting portal-systemic shunts. Although both dog and monkey had elevation of the portal pressure with occlusion, this was more pronounced in the dog (monkey; 29.2 [plus or minus] 1.8 mm. Hg; dog 36.0[plus or minus]1.9 mm. Hg). This study suggests that portal-systemic shunts do decompress the portal vein in the monkey during hemorrhagic shock.