Acute Pancreatitis in the Setting of Normal Serum Pancreatitic Enzyme Levels

Abstract

There have been many reports of acute pancreatitis with normal serum amylase levels but acute pancreatitis with normal serum lipase levels is exceedingly rare. This is not uncommon given that amylase has a relatively short half-life of about ten hours with normalization in about three to five days while lipase may remain elevated for up to two weeks. A 44 year-old male with a past medical history of hypertension and diabetes mellitus presented to the Emergency Department complaining of nausea with non-bloody and non-bilious emesis, non-bloody diarrhea, epigastric pain, anorexia and chills for the past several days. The epigastric pain is sharp and radiates to the back. It is aggravated with food intake and lying supine. The patient admits to using alcohol every weekend and consumes several beers each session. His last alcohol intake was about one week prior. He denies tobacco or illicit drug use.His vitals on admission were notable for a fever of 101.5 degrees Fahrenheit and sinus tachycardia. The physical exam was notable for dry mucous membranes and severe epigastric tenderness with guarding.The remainder of the exam was unremarkable. His complete blood count and basic metabolic panel were within normal limits. Liver function tests were only notable for an elevated gammaglutamyl transpedtidase and an elevated lactate dehydrogenase. Serum amylase and lipase levels were found to be within normal limits. A lipid panel including triglycerides was also found to be within normal limits. A chest x-ray showed a small left-sided pleural effusion. The patient was admitted to the medicine service for the inability to tolerate oral intake and treatment for acute gastroenteritis.On day three of hospitalization, the patient was still not able to tolerate oral intake, developed worsening abdominal pain and a low grade fever. Repeat blood work revealed a white blood cell count of 15,300 cells per microliter. A Computed Tomography (CT) scan of the abdomen and pelvis with intravenous and oral contrast was pursued and showed extensive pancreatic edema and peripancreatic stranding consistent with acute pancreatitis. No pseudocysts or calcifications were seen. A repeat serum amylase and lipase were within normal limits. Based on clinical presentation and radiological findings, the diagnosis of acute pancreatitis was made. The patient was started on aggressive intravenous fluid hydration, pain management and bowel rest, with improvement in symptoms. On day five of hospitalization the patient was able to tolerate a regular diet with almost complete resolution of his epigastric pain. Clinical symptoms and radiological findings are all that is needed to make the diagnosis of acute pancreatitis and medical care providers should not exclude this diagnosis based on normal serum levels of amylase and lipase enzymes as they can normalize early on in the course of this disease.