A 47-year-old presents to the clinic with a 3-day history of severe mid-epigastric abdominal pain radiating to the back. The patient has hypertension, diabetes mellitus, and hypertriglyceridemia. Prescription medications include enalapril, metformin, sitagliptin, glargine, lispro, and fenofibrate. The patient has not had a cigarette in more than 35 years, and reports only having 1 or 2 drinks during special occasions such as weddings and family reunions. The blood pressure is 146/90 mm Hg, the heart rate is 88/min, the respiratory rate is 10/min, and the temperature is 37.8°C (100.0°F). On physical examination, the patient appears uncomfortable but alert. The visualization of the sclera is negative for jaundice. The neck is supple and non-tender without nodules. There are no heart murmurs. The lungs are clear to auscultation bilaterally. The palpation of the abdomen elicits pain in the epigastric region. The liver is palpable along the costal margin, and the Murphy's sign is negative. The laboratory results are as follows: Na+ 138 mEq/L K+ 4.2 mEq/L Cl- 108 mmol/L HCO-3 20 mmol/L BUN 18 mg/dL Cr 1.0 mg/dL Glucose 154 mg/dL LDL 117 mg/dL HDL 48 mg/dL TG 942 mg/dL AST 45 IU/L ALT 48 IU/L GGT 27 IU/L Amylase 110 U/L Lipase 250 U/L According to the clinical vignette, which of the following is the most likely diagnosis of the patient?

Superior mesenteric artery embolism

A 46-year-old man is brought to the emergency department because of severe epigastric pain and vomiting for the past 4 hours. The pain is constant, radiates to his back, and is worse on lying down. He has had 3–4 episodes of greenish-colored vomit. He was treated for H. pylori infection around 2 months ago with triple-regimen therapy. He has atrial fibrillation and hypertension. He owns a distillery on the outskirts of a town. The patient drinks 4–5 alcoholic beverages daily. Current medications include dabigatran and metoprolol. He appears uncomfortable. His temperature is 37.8°C (100°F), pulse is 102/min, and blood pressure is 138/86 mm Hg. Examination shows severe epigastric tenderness to palpation with guarding but no rebound. Bowel sounds are hypoactive. Rectal examination shows no abnormalities. Laboratory studies show: Hematocrit 53% Leukocyte count 11,300/mm3 Serum Na+ 133 mEq/L Cl- 98 mEq/L K+ 3.1 mEq/L Calcium 7.8 mg/dL Urea nitrogen 43 mg/dL Glucose 271 mg/dL Creatinine 2.0 mg/dL Total bilirubin 0.7 mg/dL Alkaline phosphatase 61 U/L AST 19 U/L ALT 17 U/L γ-glutamyl transferase (GGT) 88 u/L (N=5–50 U/L) Lipase 900 U/L (N=14–280 U/L) Which of the following is the most appropriate next step in management?

Endoscopic retrograde cholangio-pancreatography

Acute pancreatitis diagnosis for USMLE Step 2 CK: High-Yield Internal Medicine Lessons

Etiology - Pancreas on Fire

Gallstone Pancreatitis: Anatomy and Stone Location

📌 I GET SMASHED

Idiopathic
Gallstones (commonest)
Ethanol (2nd commonest)
Trauma
Steroids
Mumps/Malignancy
Autoimmune
Scorpion sting
Hyperlipidemia/Hypercalcemia
ERCP
Drugs (e.g., Azathioprine, Diuretics)

⭐ Gallstones and alcohol abuse account for >70% of acute pancreatitis cases. Severe hypertriglyceridemia (>1000 mg/dL) is another classic, albeit less common, cause.

Clinical Features - Belly Ache Drama

Primary Symptom: Acute, severe, persistent epigastric pain.
- Radiation: Often "bores" straight through to the back.
- Relief: Sitting up and leaning forward.
- Aggravation: Lying supine, eating.
Associated Features: Nausea, vomiting (which doesn't relieve the pain), anorexia.
On Examination:
- Local: Epigastric tenderness, guarding, diminished bowel sounds.
- Systemic: Fever, tachycardia, hypotension (SIRS).

⭐ Ominous Signs: Cullen's (periumbilical) & Grey Turner's (flank) signs suggest retroperitoneal hemorrhage from severe necrotizing pancreatitis.

Cullen's and Grey Turner's signs in acute pancreatitis

Diagnostic Criteria - The Detective's Toolkit

Diagnosis requires 2 of 3 of the revised Atlanta criteria:
- Clinical Presentation: Acute onset of persistent, severe, epigastric abdominal pain, often radiating to the back.
- Laboratory Findings: Serum lipase or amylase elevation ≥3 times the upper limit of normal.
  - 💡 Lipase is preferred due to higher specificity and longer half-life.
- Imaging Findings: Characteristic findings on contrast-enhanced CT (CECT), MRI, or transabdominal ultrasound.

CT/MRI findings in acute pancreatitis

⭐ If characteristic abdominal pain is present along with a lipase/amylase level ≥3x the upper limit of normal, imaging is not required to confirm the diagnosis.

Severity Scoring - Counting the Damage

BISAP Score: Simpler bedside tool. Score ≥3 suggests severe disease & ↑ mortality.
- BUN >25 mg/dL
- Impaired mental status (GCS <15)
- SIRS criteria met
- Age >60 years
- Pleural effusion on imaging
Ranson's Criteria: Classic but cumbersome (needs 48h data). Score ≥3 indicates severity.
APACHE II: General ICU severity score, not specific to pancreatitis but accurate.
CT Severity Index (Balthazar): Best performed >72 hours after onset to assess for necrosis.

⭐ A BISAP score of 0 is associated with <1% mortality, making it excellent for ruling out severe pancreatitis early on the floor.

High‑Yield Points - ⚡ Biggest Takeaways

Diagnosis requires 2 of 3 criteria: acute epigastric pain radiating to the back, lipase or amylase ≥3x the upper limit of normal, or characteristic imaging findings.

Lipase is more specific and sensitive than amylase; it remains elevated longer.

Abdominal ultrasound is the best initial imaging test to identify gallstones as the cause.

Contrast-enhanced CT is the gold standard for detecting complications like necrosis, not for initial diagnosis.

Ranson's criteria and APACHE II scores are for assessing prognosis and severity, not for diagnosis.

Hypocalcemia is a poor prognostic indicator resulting from fat saponification.

Continue reading on Oncourse

CONTINUE READING — FREE

or get the app

App Store|Google Play

Acute pancreatitis diagnosis