Kinetics of oxygen in peritoneal cavity. Effects of chemical peritonitis and intraperitoneally administered colloids in rats

Abstract

Intraperitoneal oxygen tensions were measured in rats by means of intraabdominally implanted Silastic tonometers. Under normal conditions the intraperitoneal p O 2 varied between 40 and 50 mm Hg and it responded readily to increased systemic oxygen supply. In early phases of adhesion peritonitis induced by intraabdominal injection of colloidal silica elevation of intraperitoneal p O 2 by increasing the arterial blood p O 2 was higher than normal whereas the disappearance rate of intraabdominally administered gaseous or dissolved oxygen was normal or slightly low. In advanced peritonitis elevation of intraabdominal p O 2 by increasing the systemic oxygen supply was reduced below normal and the disappearance rate of intraperitoneally administered oxygen was also decreased. These observations together with our earlier results demonstrates that both the peritoneal oxygen consumption and the transfer of oxygen through the peritoneal membrane undergo specific changes during progression of peritonitis. After intraperitoneal administration of dextran 40 (Rheomacrodex) both the response of intraperitoneal p O 2 to oxygen breathing and the disappearance rate of oxygen from the abdominal cavity were reduced below the control values. Corresponding effects could not be seen after intraabdominal administration of another colloid, degraded gelatin (Haemaccel). Intrarectal insufliation of gaseous oxygen caused no changes in intraperitoneal or blood oxygen tensions.