Ranson signs and necrosis of the pancreas in acute necrotising pancreatitis.

The value of Ranson signs as an indicator of the extent of pancreatic parenchymal necrosis in acute pancreatitis was investigated in 84 patients. Ranson signs could be compared with histologic extent of pancreatic necrosis in 69 cases. The overall mortality rate was 38/84 (45%). The mortality risk increased with the number of positive Ranson signs (correlation coefficient 0.96). The mean total of Ranson signs showed linear increase with extent of parenchymal necrosis up to 75% (from 2.9 signs at no necrosis to 5.4 signs at 75% necrosis, but only 4.7 signs at 76-100%). A similar relationship was found between extent of necrosis and mortality rate. Although the number of positive Ranson signs correlated with the extent of necrosis in resected pancreas (coefficient 0.96), the signs did not adequately predict necrosis in total pancreas. Ranson criteria can be accepted as prognostic signs even when acute necrotizing pancreatitis is treated with resection. The Ranson factors also correlate with necrosis, but do not alone reliably establish its extent in individual cases.