Abstract
The impact of acute cardiac dysfunction on the gastrointestinal tract was investigated in anesthetized and instrumented pigs by sequential reductions of cardiac output (CO). Using a cardiac tamponade (n = 6) or partial inferior caval vein balloon inflation (n = 6), CO was controllably reduced for 1 h each to 75% (CO(75%)), 50% (CO(50%)), and 35% (CO(35%)) of the baseline value. Cardiac output in controls (n = 6) was not manipulated and maintained. Mean arterial pressure, superior mesenteric arterial blood flow, and intestinal mucosal perfusion started to decrease at CO(50%) in the intervention groups. The decrease in superior mesenteric arterial blood flow was non-linear and exaggerated at CO(35%). Systemic, venous mesenteric, and intraperitoneal lactate concentrations increased in the intervention groups from CO(50%). Global and mesenteric oxygen uptake decreased at CO(35%). In conclusion, gastrointestinal metabolism became increasingly anaerobic when CO was reduced by 50%. Anaerobic gastrointestinal metabolism in low CO can be detected using intraperitoneal microdialysis.