Experimental acute pancreatitis in dogs. 3. The nature of the phospholipase activity of pancreatic exudate

Long peritoneal lavage decreases pancreatic sepsis in acute pancreatitis

Late infection of devitalized pancreatic and peripancreatic tissue has become the major cause of morbidity in severe acute pancreatitis. Previous experience found that peritoneal lavage for periods of 48 to 96 hours may reduce early systemic complications but did not decrease late pancreatic sepsis. A fortunate observation led to the present study of the influence of a longer period of lavage on late sepsis. Twenty-nine patients receiving primary nonoperative treatment for severe acute pancreatitis (three or more positive prognostic signs) were randomly assigned to short peritoneal lavage (SPL) for 2 days (15 patients) or to long peritoneal lavage (LPL) for 7 days (14 patients). Positive prognostic signs averaged 5 in both groups but the frequency of five or more signs was higher in LPL (71%) than in SPL (47%). Eleven patients in each group had early computed tomographic (CT) scans. Peripancreatic fluid collections were shown more commonly in LPL (82%) than in SPL (54%) patients. Longer lavage dramatically reduced the frequency of both pancreatic sepsis (22% LPL versus 40% SPL) and death from sepsis (0% LPL versus 20% SPL). Among patients with fluid collections on early CT scan, LPL led to a more marked reduction in both pancreatic sepsis (33% LPL versus 83% SPL) and death from sepsis (0% LPL versus 33% SPL). The differences were even more striking among 17 patients with five or more positive prognostic signs. In this group the incidence of pancreatic sepsis was 30% LPL versus 57% SPL and of death from sepsis 0% (LPL) versus 43% (SPL) (p = 0.05). In these patients, overall mortality was also reduced (20% LPL versus 43% SPL). When 20 patients treated by LPL were compared with 91 other patients with three or more positive prognostic signs who were treated without lavage or by lavage for periods of 2 to 4 days, the frequency of death from pancreatic sepsis was reduced from 13% to 5%. In those with five or more signs, the incidence of sepsis was reduced from 40% to 27% (p = 0.03) and of death for sepsis from 30% to 7% (p = 0.08). These findings indicate that lavage of the peritoneal cavity for 7 days may significantly reduce both the frequency and mortality rate of pancreatic sepsis in severe acute pancreatitis.

Experimental pancreatitis in the rat. Ductal factors in sodium taurocholate-induced acute pancreatitis

Spreading of injected material and ductal resistance were studied in the rat pancreas after intraductal injection of Indian ink, human serum or sodium taurocholate. Indian ink filled the main pancreatic duct and small ductules revealing the lobular structure in macroscopic preparation. Escape into the interstitium was observed both in the macroscopic preparations and in histologic sections. Human IgG was demonstrated immunohistochemically in single acinar cells and around acinar cells after intraductal injection of human serum. The changes were most pronounced at 15 min and at 6 h after the injection but were almost resolved at 24 h. The intraductal pressure was registered during sodium taurocholate infusion. The pancreatic duct ruptured at the pressure of 82 mm Hg in average. It was concluded that in the ductal model of experimental acute pancreatitis the infusion causes ruptures in pancreatic ducts and the infusate escapes into the interstitium where it remains for several hours.

Elastic tissue injury in human acute pancreatitis

Pancreatic vessel wall alterations were studied in tissue material obtained from six patients subjected to resection of the gland for acute necrotizing pancreatitis. Special attention was paid to elastic tissue damage, which was studied using special stains in light and electron microscopy. Vascular wall elastic laminae showed changes varying from fragmentation to complete dissolution. The outer elastic lamina was more consistently affected. Elastic tissue damage was observed in pancreatic areas with minor acinar alterations and in vessels with otherwise relatively well-preserved walls. These observations suggest 1/ an early participation of elastase in the production of tissue damage in human acute pancreatitis and 2/ a primary role for elastic tissue injury in the vascular alterations leading to haemorrhage and tissue necrosis through ischaemia.

The role of peritoneal lavage in severe acute pancreatitis

Encouraged by reports of the therapeutic efficacy of peritoneal lavage in small series of five or six patients with acute pancreatitis, we have evaluated this treatment in 24 patients with "severe" pancreatitis. One hundred and three patients with "severe" pancreatitis (28% mortality) were separated from 347 with "mild" pancreatitis (0.9% mortality) by previously described early objective signs. Early treatment (Day 0-7) of "severe" pancreatitis included peritoneal lavage through catheters placed nonoperatively in 18 (Group A) and by catheters placed at laparotomy in six (Group C). Early treatment of nonlavaged patients with "severe" pancreatitis was by standard nonoperative measures in 61 (Group B) and included early operation in 18 (Group D). Lavage was continued for 48-96 hours, usually using 36-48 L/24 hours of balanced isotonic dialysate fluid, and was uncomplicated. Lavage led to striking immediate clinical improvement and no lavaged patient (Groups A and C) died during the first 10 days of treatment of pancreatitis. By contrast, 45% of deaths in nonlavaged patients (Group B and D) occurred during this early period, usually from cardiovascular or respiratory failure. Although lavage reduced mortality in subgroups of patients, ultimate overall survival was no affected (Group A, 83%; B, 84%; C, 33%; D,33%). Late peripancreatic abscesses caused most deaths in lavaged patients. These data show that peritoneal complications of severe acute pancreatitis and dramatically reduces early mortality. Lavage does not prevent the late local sequelae of peripancreatic necrosis.