BACKGROUND: Raised serum amylase and lipase levels are observed in several abdominal diseases. AIM: Assessing the validity of serum amylase and lipase for the differential diagnosis between acute pancreatitis/acutized chronic pancreatitis, biliary tract disease, perforated gastroduodenal ulcer and acute appendicitis. PATIENTS E METHODS: Prospective study including 134 individuals: 38 with acute pancreatitis/acutized chronic pancreatitis, 35 with biliary tract disease, 17 with perforated gastroduodenal ulcer and 44 with acute appendicitis, mean age (standard deviation) of 42.4 ± 17.7, 46.7 ± 18.3, 47.8 ± 12 and 33.7 ± 17.8 years, respectively. Serum amylase and lipase were determined at admission to the emergency department. RESULTS: For the diagnosis of acute pancreatitis/acutized chronic pancreatitis, when the cutt-off levels of serum amylase were set at the upper normal range level or up to 5-fold as high, the sensitivity decreased from 92% to 74%, the specificity increased from 85% to 99%, the positive predictive value increased from 71% to 97%, and the negative predictive value decreased from 96% to 91%. For serum lipase levels similar figures were obtained for sensitivity and negative predictive value, but the specificity and positive predictive value were lower. When the combination of raised serum amylase or lipase were analyzed, a minor increase was observed in sensitivity and negative predictive value. CONCLUSIONS: For the diagnosis of acute pancreatitis/acutized chronic pancreatitis: 1) the best cut-off level for both tests was 2-times the upper normal range; 2) the sensitivities of serum amylase and lipase were similar; 3) the specificity and positive predictive value of serum amylase were slightly higher than observed for serum lipase; 4) the sensitivity but not the specificity increased when at least one between amylase or lipase was raised.
Amylases; Lipase; Pancreatitis; Abdominal pain; Peptic ulcer; Bile duct diseases; Appendicitis
