Venous Circulatory Changes in the Abdomen and Lower Extremities Attending Intestinal Distention

Abstract

Summary

1. Experimental intestinal distention of anesthetized dogs produces an elevation of intraperitoneal pressure which, however, does not increase at the same rate as the intraluminal pressure. 2. Venous pressure in the lower extremities of experimentally distended, anesthetized dogs increases with increasing intraperitoneal pressure. At the same time, the rate of blood flow from the lower extremities to the carotid is slower. 3. Shock, eventually produced by prolonged intestinal distention, is relieved by deflation, blood transfusion and the steep Trendelenburg position. 4. Intestinal distention is attended by diminished respiratory movements, stasis of abdominal and peripheral venous blood, and extravascular loss of whole blood and plasma. 5. Pressure in the inferior vena cava is not observed to be altered in experimental intestinal distentions in which the intraintestinal pressures reached 50 cm of water—a pressure in excess of the upper limit of sustained intraluminal pressure observed clinically. 6. Following a temporary initial rise in portal venous pressure, a gradual fall to a constant low level is noted with continued experimental intestinal distention. 7. Early in intestinal distention, a temporary rise in arterial blood pressure is present. 8. With the abdomen open, increase of intraluminal pressure in the anesthetized dog results in a fall of mesenteric venous pressure to a constant level. 9. In clinical intestinal obstructions, there is an increase of venous pressure in and a delay in return of blood from the lower extremities. 10. Addition or aspiration of small quantities of air from the distended rabbit intestine causes corresponding increases or decreases of intraluminal pressure. Opening the abdomen or exteriorization of segments of bowel in such an animal causes fall in intraluminal pressure.