The degree of elevation of serum lipase or amylase at admission does not predict severity of disease.17
Explore This IssueACEP News: Vol 29 – No 12 – December 2010
Urine trypsinogen-2 is a newer test that may be useful as point of care testing in settings where laboratory testing for serum pancreatic enzymes is not readily available.18
Additional laboratory tests that are useful for the diagnosis of acute pancreatitis are liver function tests and hematocrit. In patients with no history of alcohol consumption, the presence of alanine aminotransferase (ALT) elevation three times the upper limit of normal has a 95% positive predictive value for acute gallstone pancreatitis.1,4,8,19 Normal liver function tests do not exclude the diagnosis of biliary pancreatitis, as this can occur in up to 20% of patients.8 Hemoconcentration (defined as hematocrit greater than 44%) and failure of hematocrit to decrease at 24 hours are important predictors of severe pancreatitis.7
Furthermore, the absence of hemoconcentration at admission or during the first 24 hours excludes the occurrence of pancreatic necrosis in most patients1,2,20 and is strongly predictive of a benign clinical course.1
Urinary trypsinogen activation peptide is a newer test that has been shown recently to be more accurate at predicting severe acute pancreatitis, compared with hematocrit.21 As it becomes more widely available, it may be an important adjunct to clinical findings in predicting severity of disease.
CT scan at admission is rarely indicated if the diagnosis of acute pancreatitis has been made on the basis of elevated pancreatic enzymes and characteristic abdominal pain. It is reasonable to obtain a CT scan to rule out other intra-abdominal etiologies1 and to assess for complications of acute pancreatitis (such as necrosis, pseudocyst, abscess) when the time course is appropriate.
Remember that pseudocysts take about 4 weeks and pancreatic abscesses about 5 weeks to form after initial onset of symptoms.1
Pancreatic necrosis is best evaluated by obtaining a contrast-enhanced CT scan 2-4 days after admission, as CT done on admission may underestimate severity.1,7,8
Once the diagnosis of acute pancreatitis is made, the etiology should be determined. The recurrence rate of alcoholic pancreatitis is about 50%; in biliary pancreatitis, it is up to 61%.1,7,10 Prior to hospital discharge, it is imperative that these two leading causes of pancreatitis are fully evaluated.
Social history should be reviewed thoroughly, specifically to quantify alcohol use. If there is no history to support alcohol as the etiology, the patient should undergo a gallbladder ultrasound during his or her hospitalization. Furthermore, if biliary pancreatitis is diagnosed, there should be a definitive treatment plan (i.e., cholecystectomy or ERCP with sphincterotomy) in effect at the time of discharge to prevent recurrent episodes.1,3,4,7