Abstracts
1997 Digestive Disease Week

Ranson's criteria and mortality in non-pancreatic critical illness.

J Bonadies, A Benbrahim, K Charpentier, R Reinhold. Department of Surgery, Hospital of Saint Raphael, New Haven, CT.

Purpose: Ranson's criteria have proven a useful predictor of mortality in acute pancreatitis. The Ranson variables, however, are not specific for pancreatitis but rather general markers of organ system dysfunction. We therefore studied Ranson's original criteria as a predictor of mortality in non-pancreatic critical illness.

Methods: Over a 14 month period, all patients admitted to the surgical intensive care unit (SICU) for >=48 hours, excluding those with the diagnosis of pancreatitis, were included in the study. Ranson's criteria at admission (Age, WBC, glucose, LDH, AST) and at 48 hours (BUN increase, hematocrit decrease, calcium, PO₂, base deficit, fluid sequestration) were recorded on all patients. The hematocrit was adjusted by 3.3 percentage points for each unit of blood transfused. PO₂ values were analyzed regardless of FiO₂. In addition, we corrected for the effect of supplemental O₂ using a ratio of PO₂/FiO₂. As per Ranson's original paper, patients were stratified to one of four groups based on the total number of signs (0-2, 3-4, 5-6, >6). Hospital mortality was compared with the number of Ranson's signs at admission, at 48 hours and with the total criteria.

Results: 107 patients met the criteria for the study and had all 11 Ranson's criteria measured. The mean age was 70.6 (16-94 15.2), with 45 females and 62 males. Ten surgical services contibuted to the cohort (30 vascular, 29 general surgery, 22 orthopedic and 26 other). The mean SICU length of stay (LOS) was 4.6 days (2-34) and the mean total LOS was 13.6 days (3-44). Thirty-nine patients (36%) had 0-2 Ranson's signs, 51 (48%) had 3-4 signs, 15 (14%) had 5-6 signs and 2 patients (2%) had >6 signs. Mortality for patients with 0-2 Ranson's signs was 2.5%; 3-4, 9.8%; 5-6, 13.3% and >6, 50% (p=0.07). Admission Ranson's signs alone were poor predictors of mortality (p=0.9) while those 6 signs collected at 48 hours were predictive at p=0.06. As independant variables, base deficit and fluid sequestration >6L were the best predictors of mortality (p<0.01 and p<0.03 respectively).

When analyzed using the correction for FiO₂, mortality rates changed for each group as follows: 0-2, 0%, 3-4, 7.5%, 5-6, 18% and >6,33% and became statistically significant (p < 0.05).

Conclusions: Ranson's criteria can predict mortality in non-pancreatic critical illness with results parallelling that of Ranson's original work in acute pancreatitis. The accuracy of the system is improved by modifying PO₂ values for supplemental oxygen. The simplicity, accessibility and familiarity of the Ranson variables facilitates the utility of this scoring system.