<prompt> Which of the following is most diagnostic investigation for acute pancreatitisSerum amylaseSerum lipaseSerum P-isoamylaseSerum LDH  <response>: Diagnosis of Acute pancreatitis Corner Stone of the diagnosis of AP: Clinical findings elevation of pancreatic enzyme level in the plasma Pancreatic enzymes A threefold or higher elevation of amylase lipase levels confirms the diagnosis Amylases serum half - life is shoer as compared with lipase Lipase is also a more specific marker of AP because serum amylase levels can be elevated in a number of conditions, such as peptic ulcer disease, mesentric ischaemia, salpingitis and microamylasemia Patients with AP are typically hyperglycemic; they can also have leukocytosis and abnormal elevation of liver enzyme levels Elevation of ALT levels in the serum in the context of AP has a positive predictive value of 95 in the diagnosis of acute biliary pancreatitis X-Ray abdomen Localized ileus of duodenum and proximal jejunum sentinel loop or that of transverse colon up to its mid point colon cut off sign IOC for acute pancreatitis : CECT Ref: Sabiston 20th edition Pgno :1524-1528 