The following cases and commentary, which address alcohol abuse, are excerpted from ACP's Medical Knowledge Self-Assessment Program (MKSAP 15).
Case 1: Abdominal pain followed by agitation
A 47-year-old man with a long-standing history of alcoholism is hospitalized for abdominal pain, nausea, and vomiting of 7 days' duration. His last drink was 6 days ago. He has lost approximately 10% of his body weight over the past 4 months; he states that his weight loss was caused by drinking alcohol and not eating.
On physical examination, he appears cachectic. Temperature is 37.1°C (98.8°F), blood pressure is 100/70 mm Hg, pulse rate is 110/min, and respiration rate is 18/min. BMI is 17. He is not confused or tremulous. There is midepigastric tenderness without rebound. Bowel sounds are present. Neurologic examination is normal.
Laboratory studies show: amylase, 300 U/L; lipase, 150 U/L; sodium, 130 mEq/L (130 mmol/L); potassium, 3.4 mEq/L (3.4 mmol/L); chloride, 90 mEq/L (90 mmol/L); bicarbonate, 20 mEq/L (20 mmol/L); phosphorus, 3.5 mg/dL (1.1 mmol/L); calcium, 9.0 mg/dL (2.2 mmol/L); and urinalysis, positive for ketones.
The patient receives immediate thiamine replacement, folic acid supplementation, and a multivitamin followed by vigorous intravenous fluid replacement with 5% dextrose and normal saline with aggressive potassium replacement. Morphine is used to control pain.
Eighteen hours later, the patient's abdominal pain has improved but he becomes restless, agitated, and extremely weak and is barely able to raise his extremities against gravity.
Which of the following is the most likely cause of this patient's new findings?
Case 2: Fever, cough and sputum
A 45-year-old woman is evaluated for fever, diminished appetite, weight loss, and cough productive of foul-smelling sputum of 2 weeks' duration. She has a history of chronic alcoholism and frequent hospital admissions for alcohol-withdrawal seizures, with the most recent episode occurring 3 weeks ago.
On physical examination, temperature is 38.3 oC (101.0 oF), blood pressure is 130/84 mm Hg, pulse rate is 80/min, and respiration rate is 18/min. Her breath is foul smelling and dentition is poor. Pulmonary examination reveals some crackles and rhonchi in the right anterior chest.
Laboratory studies indicate a leukocyte count of 12,500/µL (12.5 × 109/L) with 8% band forms. The chest radiograph is shown.
Sputum Gram stain results indicate gram-positive cocci in chains, gram-negative bacilli, and gram-positive bacilli.
Which of the following empiric antimicrobial regimens should be initiated?
Case 3: Postprandial pain
A 42-year-old man is evaluated in the hospital for a 1-year history of postprandial abdominal pain that radiates to the back and that is worse after eating and is associated with nausea. He has not had vomiting, weight loss, or change in bowel habits. The patient has had at least five alcohol-containing drinks a day for 20 years; he has reduced his intake in the past year because of continued abdominal pain.
On physical examination, vital signs are normal; BMI is 24. There is mild epigastric tenderness with no guarding or rebound and normal bowel sounds. Laboratory studies reveal normal complete blood count, fasting glucose, and liver chemistry tests; amylase is 221 U/L and lipase 472 U/L. Radiography, ultrasonography, and CT scan of the abdomen are normal, as is esophagogastroduodenoscopy.
Which of the following is the most appropriate next step in the evaluation of this patient?
A. Biliary scintigraphy
B. Colonoscopy C. Endoscopic retrograde cholangiopancreatography
D. Measurement of stool elastase
Case 4: Evaluating acute pancreatitis
A 44-year-old man with a long history of alcohol abuse is evaluated on the sixth day of hospitalization for acute pancreatitis. On admission to the hospital, he was afebrile, the blood pressure was 150/88 mm Hg, the pulse rate was 90/min, and the respiration rate was 16/min. Abnormal findings were limited to the abdomen, which was flat and tender to palpation without peritoneal signs. Bowel sounds were normal. Plain abdominal and chest radiographs were normal. Abdominal ultrasonography revealed a diffusely enlarged, hypoechoic pancreas without evidence of gallstones or dilated common bile duct. He was treated with aggressive intravenous hydration and opioid analgesia. For the past 2 days, the patient has had repeated febrile episodes, persistent severe abdominal pain, and increasing shortness of breath.
On physical examination, the temperature is 38.6°C (101.5°F), the blood pressure is 98/60 mm Hg, the pulse rate is 112/min, and the respiration rate is 22/min; oxygen saturation is 92% with the patient breathing oxygen 3 L/min. Breath sounds are decreased at the base of both lungs. The abdomen is distended and diffusely tender with hypoactive bowel sounds. Laboratory studies reveal leukocyte count of 19,800/µL (19.8 × 109/L), creatinine 1.4 mg/dL (106.8 µmol/L), amylase 388 U/L, and lipase 842 U/L.
Which of the following is the most appropriate next step in the evaluation of this patient?
A. CT scan of the abdomen with intravenous contrast
B. Endoscopic retrograde cholangiopancreatography C. Endoscopic ultrasonography
D. Stool chymotrypsin
Case 5: Anorexia with acute pancreatitis
A 34-year-old woman is evaluated for continued severe mid-epigastric pain that radiates to the back, nausea, and vomiting 5 days after being hospitalized for acute alcohol-related pancreatitis. She has not been able to eat or drink and has not had a bowel movement since being admitted.
On physical examination, the temperature is 38.2°C (100.8°F), the blood pressure is 132/84 mm Hg, the pulse rate is 101/min, and the respiration rate is 20/min. There is no scleral icterus or jaundice. The abdomen is distended and diffusely tender with hypoactive bowel sounds.
Laboratory studies show: leukocyte count, 15,400/µL (15.4 × 109/L); aspartate aminotransferase, 189 U/L; alanine aminotransferase, 151 U/L; bilirubin (total), 1.1 mg/dL (18.8 µmol/L); amylase, 388 U/L; and lipase, 924 U/L.
CT scan of the abdomen shows a diffusely edematous pancreas with multiple peripancreatic fluid collections, and no evidence of pancreatic necrosis.
Which of the following is the most appropriate next step in the management of this patient?
A. Enteral nutrition by nasojejunal feeding tube
B. Intravenous imipenem C. Pancreatic débridement
D. Parenteral nutrition
Answers and commentary
Correct answer: D. Hypophosphatemia.
Severe hypophosphatemia rarely manifests as physiologic disturbances and most often develops in patients with chronic alcoholism who have poor oral intake, decreased intestinal absorption due to frequent vomiting and diarrhea, and increased kidney excretion due to the direct effect of ethanol on the tubule. Despite total body phosphorus depletion, these patients may have normal serum phosphorus levels on admission to the hospital.
Severe hypophosphatemia often develops over the first 12 to 24 hours after admission, usually because of intravenous glucose administration. This agent helps to release insulin and rapidly reverses alcoholic ketoacidosis, which causes phosphate to shift into cells.
The sudden development of hypophosphatemia may cause confusion, rhabdomyolysis, hemolytic anemia, and severe muscle weakness that can lead to respiratory failure. Treatment involves preventing the serum phosphorus level from decreasing below 1 mg/dL (0.32 mmol/L). Oral phosphate is the preferred treatment in this setting, but intravenous administration may be needed if oral therapy cannot be tolerated.
Hypercalcemia may manifest as decreased neuromuscular excitability that causes decreased muscular tone. Hypercalcemia is most commonly caused by alterations in calcium absorption from the gut and bone resorption due to primary hyperparathyroidism, malignancy, and granulomatous diseases. Primary hyperparathyroidism and thiazide diuretic use also may cause this condition. The development of hypercalcemia in this patient is unlikely.
Hypokalemia can cause diffuse muscle weakness, gastrointestinal tract atony, respiratory failure, and cardiac arrhythmias. In chronic hypokalemia, muscle weakness is unusual in patients with a serum potassium level above 2.5 mEq/L (2.5 mmol/L) but may be precipitated by a sudden decrease in potassium. However, the risk of profound hypokalemia is low in a patient receiving potassium supplementation. Furthermore, hypokalemia would not explain this patient's mental status changes.
Early signs of hyponatremia typically include nausea, vomiting, and headaches; progressive manifestations include impaired mental status and seizures. These symptoms are not compatible with this patient's presentation.
- In the hospital setting, patients with chronic alcoholism may have normal serum phosphorus levels on admission to the hospital but often develop severe hypophosphatemia over the first 12 to 24 hours.
Correct answer: A. Ampicillin-sulbactam.
This patient's history of alcohol abuse and alcohol-withdrawal seizures puts her at risk for aspiration pneumonia. She now presents with a lung abscess, characterized radiologically by a cavity with an air-fluid level, which probably occurred as a complication of aspiration pneumonia. Lung abscesses are polymicrobial infections caused by anaerobic bacteria that are normally present in the mouth; micro-aerophilic streptococci, viridans streptococci, and gram-negative enteric pathogens have also been implicated. In studies using sample techniques that avoid oral contamination, anaerobes are found in about 90% of patients with lung abscess and are the only organisms isolated in about half. Possible anaerobes in patients with lung abscess as a complication of aspiration pneumonia include Peptostreptococcus species, Fusobacterium nucleatum, Prevotella melaninogenica, and Bacteroides species (including B. fragilis). Of the choices listed, only ampicillin-sulbactam would have a broad enough spectrum to cover the likely pathogens.
Of the other antimicrobial choices, levofloxacin and aztreonam would not be effective in treating oral anaerobes, and ceftriaxone would be effective in treating some oral anaerobic species but not β-lactamase–producing strains.
Although metronidazole is highly active in vitro against most anaerobes, it is not active against microaerophilic streptococci and some anaerobic cocci.
- Patients with lung abscess as a complication of aspiration pneumonia require treatment with an antimicrobial agent effective against β-lactamase–producing strains of oral anaerobes.
Correct answer: C. Endoscopic retrograde cholangiopancreatography.
Establishing the diagnosis of chronic pancreatitis in a patient with early disease can be difficult. No blood or stool tests are currently available for the accurate diagnosis of early chronic pancreatitis. This patient's pain is most likely secondary to chronic pancreatitis with minimally elevated pancreatic enzymes and a history of harmful drinking. The patient has no evidence of exocrine or endocrine insufficiency and thus likely has early chronic pancreatitis. Normal liver enzymes, normal upper endoscopy, and a normal abdominal ultrasonography and CT scan of the abdomen make biliary causes and peptic ulcer disease less likely the cause of pain.
Endoscopic retrograde cholangiopancreatography (ERCP) has a sensitivity of nearly 95% for chronic pancreatitis and can show ductal dilation, strictures, and irregularity in both the main duct and its side branches. CT scan of the abdomen has a sensitivity of up to 90% for diagnosing chronic pancreatitis and should be ordered with thin cuts of the pancreas to improve sensitivity.
Endoscopic ultrasonography may also be used to diagnose chronic pancreatitis with sensitivities equal to ERCP for moderate and advanced chronic pancreatitis but with lower sensitivity and specificity for mild and early chronic pancreatitis. Magnetic resonance cholangiopancreatography does not have sensitivities or specificities that match ERCP in the diagnosis of chronic pancreatitis at this time and cannot be routinely recommended. Biliary scintigraphy is used to diagnose acute cholecystitis and does not have a role in diagnosing chronic pancreatitis. Stool elastase can be abnormal in patients with more advanced chronic pancreatitis, particularly those who have malabsorption. However, stool elastase has poor sensitivity in patients with early chronic pancreatitis. Colonoscopy has a low yield in patients with upper abdominal pain.
- Endoscopic retrograde cholangiopancreatography is the most sensitive imaging test for chronic pancreatitis.
Correct answer: A. CT scan of the abdomen with intravenous contrast.
Pancreatic necrosis should be suspected in a patient with severe acute pancreatitis whose condition is not improving or is worsening after 5 days or more of treatment. Pancreatic necrosis on CT scan can be identified as unenhanced areas of the pancreas. Neither endoscopic retrograde cholangiopancreatography nor endoscopic ultrasonography can detect the presence of pancreatic necrosis in the setting of acute pancreatitis. Stool chymotrypsin can be measured when chronic pancreatitis is suspected to help evaluate for decreased pancreatic function.
Pancreatic necrosis is the most important predictor of poor outcome in acute pancreatitis. Patients who develop pancreatic necrosis should be given antibiotic prophylaxis, usually with imipenem. The necrosis should be sampled for the presence of infection, and if infection is present, surgical débridement is recommended.
- CT scan of the abdomen with intravenous contrast is the most sensitive test to diagnose pancreatic necrosis.
Correct answer: A. Enteral nutrition by nasojejunal feeding tube.
This patient has moderate to severe acute pancreatitis and after 5 days remains febrile, continues to be in pain, and cannot take in any oral nutrition. The patient will likely have an extended period before being able to take in oral nutrition. Two routes are available for providing nutrition in patients with severe acute pancreatitis: enteral nutrition and parenteral nutrition.
Enteral nutrition is provided through a feeding tube ideally placed past the ligament of Treitz so as not to stimulate the pancreas. Parenteral nutrition is provided through a large peripheral or central intravenous line. Enteral nutrition is preferred over parenteral nutrition because of its lower complication rate, especially a lower infection rate. A meta-analysis of six studies with 263 participants compared enteral nutrition with total parenteral nutrition. Enteral nutrition was associated with a significantly lower incidence of infections, reduced surgical interventions to control complications of pancreatitis, and a reduced length of hospital stay. In another randomized, controlled trial, enteral nutrition showed a trend towards faster attenuation of inflammation, with fewer septic complications, and also was a dominant therapy in terms of cost-effectiveness.
Imipenem therapy is only helpful in acute pancreatitis when there is evidence of pancreatic necrosis. Pancreatic necrosis is diagnosed by a contrast-enhanced CT scan that shows nonenhancing pancreatic tissue. In patients with noninfected pancreatic necrosis, antibiotics may decrease the incidence of sepsis, systemic complications (for example, respiratory failure), and local complications (for example, infected pancreatic necrosis or pancreatic abscess).
Randomized, prospective trials have shown no benefit from antibiotic use in acute pancreatitis of mild to moderate severity but may lead to development of nosocomial infections with resistant pathogens. Similarly pancreatic débridement is recommended only in patients with pancreatitis and infected pancreatic necrosis.
- Enteral feeding is the preferred route of providing nutrition in patients with severe acute pancreatitis.