Ranson’s criteria

Ranson's criteria is a scoring system that helps healthcare professionals predict the severity and mortality of acute pancreatitis, an inflammatory condition of the pancreas that occurs primarily as a result of alcohol or gallstones. 

Most of the time, acute pancreatitis is relatively mild, with the inflammation resolving in the first few days after appropriate treatment. However, in around 20% of cases, it can become more severe and cause necrosis (i.e., tissue death) of the pancreas and surrounding fatty tissue. If the disease progresses, there may be a phase of generalized inflammation, also known as a systemic inflammatory response (SIRS), triggered by the release of various inflammatory molecules and pancreatic enzymes into the blood. If left untreated, SIRS can result in significant fluid sequestration, or shifting of fluid from blood vessels into the surrounding tissues, ultimately leading to organ failure. 

The Ranson’s criteria has a total of 11 prognostic signs that reflect on the severity of acute pancreatitis. Five of these parameters are assessed upon hospital admission, whereas the rest are assessed at 48 hours into admission. At admission, the measured parameters include age over 55 years, elevated white blood cell count (WBC), hyperglycemia (i.e., elevated blood glucose), elevated lactate dehydrogenase (LDH), and elevated serum aspartate transaminase (AST). At 48 hours, the criteria include low hematocrit, elevated blood urea nitrogen (BUN), low serum calcium, hypoxemia (i.e., low blood oxygen levels), markers of a low blood pH (i.e., metabolic acidosis), and fluid sequestration. 

This scoring system aims to predict the severity of acute pancreatitis by determining if there are any signs of dehydration (e.g., high BUN), inflammation (e.g., high WBC and LDH), or organ dysfunction (e.g., hypoxemia) as well as the ability of the pancreas to regulate glucose levels (e.g., presence of hyperglycemia). 

The presence of 1 to 3 of these aforementioned criteria indicates that severe pancreatitis is unlikely, while the presence of more than 3 criteria indicates an increased risk of severe pancreatitis and higher mortality.