A 45-year-old man comes to the emergency department due to sudden-onset vomiting and severe upper abdominal pain that radiates to his back. The patient's total bilirubin is 0.9 mg/dL, aspartate aminotransferase (AST) is 98 U/L, alanine aminotransferase (ALT) is 32 U/L, and alkaline phosphatase is 98 U/L. Serum lipase is markedly increased. Abdominal ultrasound reveals a normal gallbladder and common bile duct. The diagnosis of acute pancreatitis is made, and a specific etiology is established. Which of the following additional laboratory findings is most specific for the underlying cause of this patient's pancreatitis?

Question

A 45-year-old man comes to the emergency department due to sudden-onset vomiting and severe upper abdominal pain that radiates to his back.  The patient's total bilirubin is 0.9 mg/dL, aspartate aminotransferase (AST) is 98 U/L, alanine aminotransferase (ALT) is 32 U/L, and alkaline phosphatase is 98 U/L.  Serum lipase is markedly increased.  Abdominal ultrasound reveals a normal gallbladder and common bile duct.  The diagnosis of acute pancreatitis is made, and a specific etiology is established.  Which of the following additional laboratory findings is most specific for the underlying cause of this patient's pancreatitis?

Quizplus · Accepted Answer

This patient's acute pancreatitis is likely related to chronic alcohol use given his >2 AST:ALT ratio and absence of gallstones on abdominal ultrasound. After gallstones, alcohol use is the second most common cause of acute pancreatitis. Ethanol induces pancreatic secretions with a high protein concentration and low fluid content. These viscous secretions are prone to precipitate and form plugs that can obstruct the lumina of the pancreatic ductules. Alcohol also causes spasms of the sphincter of Oddi and has a direct toxic effect on the acinar cells. Alcohol-related acute pancreatitis is clinically indistinguishable from pancreatitis due to other causes. However, chronic alcohol use causes a number of systemic effects due to both the direct toxic actions of ethanol and alcohol-associated vitamin deficiencies. Even in the absence of anemia, macrocytosis (mean corpuscular volume >100 fL) is often seen and is likely related to poor nutrition (eg, folate deficiency), liver disease, and/or direct toxicity of alcohol on the marrow. (Choice B) In severe acute pancreatitis, necrosis can spread into the retroperitoneal fat, omentum, mesentery, and even beyond the abdominal cavity. Large amounts of calcium bind to the released free fatty acids, forming soaps that are deposited in the areas of necrosis, which may result in hypocalcemia. However, this is a nonspecific finding that can occur with pancreatitis of any etiology, not just alcohol-related pancreatitis. (Choice C) Inflammation in acute pancreatitis may lead to dysfunction of the pancreatic islets with decreased secretion of insulin, resulting in hyperglycemia. This is a nonspecific finding that can occur with pancreatitis of any etiology, not just alcohol-related pancreatitis. (Choice D) Hypernatremia may occur in the setting of severe acute pancreatitis due to large third-space fluid loss (ie, interstitial fluid accumulation) and decreased water intake, causing subsequent hypovolemia and renal sodium retention. This finding is also not specific for alcohol-related pancreatitis. (Choice E) An increased white blood cell count is a nonspecific marker of inflammation and may occur with pancreatitis of any etiology. Educational objective: After gallstones, chronic alcohol use is the second most common cause of acute pancreatitis. Macrocytosis and an AST:ALT ratio >2 are indirect indicators of chronic alcohol consumption. Alcohol-related macrocytosis can occur independently of folate deficiency. __________ References: Pathophysiology of alcoholic pancreatitis: an overview. (http://www.ncbi.nlm.nih.gov/pubmed/17167828) Diagnosis of alcoholic liver disease. (http://www.ncbi.nlm.nih.gov/pubmed/25206273) Traditional markers of excessive alcohol use. (http://www.ncbi.nlm.nih.gov/pubmed/14984240)

A 45-Year-Old Man Comes to the Emergency Department Due to Sudden-Onset