Chest
-
To define whether increases in gastric intramural tissue CO2 and H+ increase during experimentally induced peritonitis with circulatory shock as they do under conditions of hemorrhagic shock and cardiac arrest. ⋯ In contrast to the gastric acid base changes that accompany hemorrhagic shock, in which there is an early and prominent increase in both PCO2 and [H+] in close relationship to decreases in cardiac output and arterial pressure, there was a prominent increase in gastric [H+] but only a delayed rise in gastric intramural PCO2. Arterial blood lactate and central venous oxygen saturation were earlier indicators of perfusion failure. Since the bicarbonate concentration in the stomach wall was substantially greater than that of simultaneously measured arterial blood, this has bearing on the current clinical method of gastric tonometry which assumes that arterial blood bicarbonate is equivalent to gastric wall bicarbonate.