Clinical implication of increased pancreatic enzymes in ICU patients.

129 Elevations in serum levels of pancreatic enzymes are usually in the range of 14–80% in intensive care unit (ICU) patients who have no prior pancreatic pathology. 1,2 Although most of these patients do not develop clinical pancreatitis, pancreatic damage associated with elevated pancreatic enzymes is present. It is difficult to assess the clinical symptoms and signs of acute pancre-atitis in ICU patients, especially in comatose, sedated, or mechanically ventilated patients. Serum amylase and lipase exceeding 3 times the upper normal limit are considered part of the criteria to diagnose acute pan-creatitis. 3 However, neither amylase nor lipase is specific for acute pancreatitis, and elevation of amylase and lipase does not correlate with the severity of pancre-atitis. Imaging studies including abdominal ultrasonog-raphy and computed tomography (CT) are important tools to assess the etiology of elevated pancreatic enzymes. Imaging work-up for pancreatic damage is indicated for ICU patients with serum amylase or lipase levels > 3 times the upper normal limit. What is the incidence of pancreatitis in ICU patients with increased serum amylase and lipase? In a recent issue of the Journal of the Chinese Medical Association, Lee et al 4 reported their retrospective study that evaluated the clinical implication of increased serum levels of amylase and lipase in 89 neurosurgery ICU patients with abdominal symptoms and signs. Nearly half of these patients (48.3%) had elevated serum amylase and lipase. Nine out of 34 (26.5%) patients who were highly suspected to have acute pancreatitis (according to symptoms , signs, serum amylase and lipase levels > 3 and > 5 times, respectively, the upper normal limit), with peri-toneal signs or fever of unknown origin, had imaging findings of pancreatitis on ultrasonography and/or CT. Only 1 of 9 patients had moderate pancreatitis; the others had mild pancreatitis. The exact causes of pan-creatitis were not shown in the study. Manjuck et al 5 found that imaging evidence of pancreatitis was present in 22% (11/50) of ICU patients with elevated lipase levels (above the upper normal limit). Denz et al 2 recently reported that 7 out of 20 (35%) ICU patients with serum lipase levels > 3 times the normal value had morphological alterations of the pancreas seen on contrast-enhanced CT. Is increased serum pancreatic enzymes in ICU patients associated with higher mortality or longer ICU stay? Liu et al 6 and Manjuck et al 5 reported that ICU patients with elevated amylase and …