Splanchnic and pancreatic tissue perfusion in experimental acute pancreatitis.

BACKGROUND: Gut hypoperfusion has a major role in the pathogenesis of multiple organ failure, which is the main cause of death in severe acute pancreatitis. The effects of experimental acute pancreatitis on splanchnic and pancreatic perfusion and oxygenation were studied to find out whether gut hypoperfusion occurs already at the same time as changes in pancreatic perfusion. METHODS: Twenty-four domestic pigs weighing 21-27 kg were randomized to severe or mild acute pancreatitis or control groups. Eight anaesthetized and mechanically ventilated pigs were intraductally infused with taurocholic acid to induce severe acute pancreatitis and eight received intraductal saline to induce mild acute pancreatitis. Eight pigs served as controls. RESULTS: Intraductally infused taurocholic acid rapidly induced severe necrotizing acute pancreatitis as assessed macroscopically and histologically. Histological changes of mild acute pancreatitis were seen in animals after intraductal saline infusion. After the induction, pancreatic tissue oxygen tension decreased promptly in severe acute pancreatitis and increased in mild acute pancreatitis. Laser-Doppler red cell flux decreased in severe acute pancreatitis. Gut pH gap and pCO2 gap decreased in 2 h after the induction of severe acute pancreatitis. Central haemodynamics were fairly stable throughout the study period in all groups. CONCLUSION: In experimental severe acute pancreatitis, splanchnic malperfusion seems to begin with pancreatic hypoperfusion before disturbances in gut microcirculation.

Pancreatic tissue perfusion in experimental acute pancreatitis.

OBJECTIVE: To investigate pancreatic tissue perfusion and oxygenation in severe and mild experimental acute pancreatitis in pigs. DESIGN: Randomised controlled experiment. SETTING: Animal laboratory, Finland. ANIMALS: 24 domestic pigs weighing 21-27 kg. INTERVENTIONS: 24 pigs were randomised into severe acute pancreatitis, mild acute pancreatitis and control groups (n = 8 in each). The pancreatic duct of eight anaesthetised and mechanically ventilated pigs was cannulated and taurocholic acid was infused into the pancreatic duct to induce severe acute pancreatitis. Eight animals received intraductally infused saline and developed mild acute pancreatitis. Eight pigs had their ducts cannulated alone, and served as controls. MAIN OUTCOME MEASURES: Pancreatic tissue oxygenation, laser Doppler red cell flux, central haemodynamics. RESULTS: Intraductally infused taurocholic acid rapidly induced macroscopically and histologically proven severe necrotising acute pancreatitis. Histological changes characterising mild acute pancreatitis were seen in animals after intraductal saline infusion. Pancreatic tissue oxygen tension decreased in the severe group and increased in the mild group during the six-hour study period. Laser Doppler red cell flux decreased in the severe group. Central haemodynamics, arterial blood gases, and acid base balances were stable throughout the study period in all groups. CONCLUSION: The present model of severe acute pancreatitis significantly impairs pancreatic oxygenation in the early phase. In mild acute pancreatitis, pancreatic oxygenation increases.

Central haemodynamics in experimental acute pancreatitis.

OBJECTIVE: To investigate central haemodynamics in severe and mild acute pancreatitis in pigs. DESIGN: Randomised controlled experiment. SETTING: Animal laboratory, Finland. SUBJECTS: 24 domestic pigs weighing 21-27 kg. INTERVENTIONS: In 8 anaesthetised and mechanically ventilated pigs the pancreatic duct was cannulated and taurocholic acid was infused to induce severe acute pancreatitis. Eight animals received intraductal saline infusion and developed mild acute pancreatitis. Eight pigs were cannulated alone and served as controls. MAIN OUTCOME MEASURES: Cardiac index, heart rate, mean arterial pressure, central venous pressure, mean pulmonary arterial pressure, pulmonary arterial occlusion pressure, haemoglobin, arterial blood gases and acid base balance. RESULTS: Intraductally infused taurocholic acid rapidly induced severe necrotising acute pancreatitis as assessed both macroscopically and histologically. Histological changes of mild acute pancreatitis were seen in animals after intraductal saline infusion. Central haemodynamics, arterial blood gases, and acid base balances were stable throughout the study period in all groups. The main finding was haemoconcentration as indicated by the increase in arterial haemoglobin concentration in pigs with mild and severe acute pancreatitis. CONCLUSION: Haemoconcentration precedes central haemodynamic alterations in experimental acute pancreatitis.