What is the appropriate workup and initial management for a patient with mid‑back pain radiating to the abdomen that is relieved by leaning forward?

Mid-Back Pain Radiating to Abdomen, Relieved by Leaning Forward

This clinical presentation is highly suggestive of acute pancreatitis, and you should immediately obtain serum lipase (or amylase) and consider contrast-enhanced CT abdomen/pelvis if the diagnosis remains uncertain or if complications are suspected. 1, 2

Immediate Diagnostic Workup

Clinical Assessment

• Confirm the classic triad: upper abdominal pain radiating to the back, pain worse with eating, and associated nausea/vomiting 2
• Pain relief with leaning forward is a characteristic positional finding that strongly suggests pancreatic pathology 1
• Assess for systemic inflammatory response syndrome (SIRS) criteria and use the Atlanta classification to identify high-risk patients who may develop complications 2

Laboratory Testing

• Serum lipase or amylase: Diagnosis requires elevation >3 times the upper limit of normal 2
• Note that amylase is no longer essential for diagnosis if lipase is available 3
• Additional prognostic markers include hematocrit, lactate, and blood urea nitrogen (BUN), though these are insufficient alone to predict severe or necrotizing pancreatitis 3
• Procalcitonin may support therapeutic decisions, particularly regarding infected necrosis 3

Imaging Strategy

• Contrast-enhanced CT should be delayed unless necrosis is suspected or diagnosis remains uncertain 3
• Optimal timing for CT is ≥72 hours, ideally after 7 days, to allow full evolution of pancreatic necrosis 3
• (Endo)sonography is mandatory to evaluate for gallstones as the underlying etiology 3
• Do NOT obtain routine imaging in the first 24 hours unless there is diagnostic uncertainty or concern for complications 3

Differential Diagnosis Considerations

While pancreatitis is the leading diagnosis, you must exclude:

• Perforated peptic ulcer (would show pneumoperitoneum on imaging) 4
• Aortic dissection (requires immediate vascular imaging if suspected)
• Posterior penetrating duodenal ulcer (may mimic pancreatic pain)
• Biliary colic or cholecystitis (ultrasound will differentiate) 3

Red flags requiring immediate imaging include: progressive neurologic deficits, cauda equina syndrome, history of cancer, fever with suspected infection, or severe trauma 4, 5

Initial Management

Fluid Resuscitation

• Early, goal-directed fluid resuscitation with balanced crystalloids improves outcomes 3
• Target central venous pressure of 12-15 mmHg, urinary output 0.5-1 mL/kg/hour, and inferior vena cava collapse index >48% 6
• Avoid excessive fluids (>3 mL/kg/hour), as this worsens outcomes 3

Pain Control

• Opioids are superior to NSAIDs and should be used as first-line analgesia 3
• Consider multimodal analgesia including systemic agents and epidural block for severe pain 6

Nutrition

• Initiate oral feeding within 24 hours as tolerated—the old "nothing by mouth" approach is obsolete 2, 3
• If oral feeding is not tolerated, enteral feeding via nasogastric or nasojejunal tubes should be started immediately 2
• Enteral nutrition reduces the risk of infected necrosis and is strongly preferred over parenteral feeding 3

Antibiotics

• Antibiotic prophylaxis is NOT recommended, even in necrotizing pancreatitis 3
• Antibiotics are indicated only with radiologically confirmed infection or systemic infection symptoms 2
• Infected necrosis is rare in the first 2 weeks 3

Etiology-Specific Interventions

Biliary Pancreatitis

• Emergency ERCP (<24 hours) is only warranted in cholangitis 3
• Without cholangitis, ERCP within 72 hours is adequate 3
• Biliary sphincterotomy and pancreatic stenting reduce post-ERCP pancreatitis 3

Hypertriglyceridemic Pancreatitis

• Plasmapheresis offers no proven benefit 3

Common Pitfalls to Avoid

• Do not order CT in the first 24-72 hours unless there is diagnostic uncertainty or suspected complications—early imaging does not change management and delays optimal timing for detecting necrosis 3
• Do not withhold oral feeding—early nutrition within 24 hours is now standard of care 2, 3
• Do not prescribe prophylactic antibiotics—they do not prevent infected necrosis and promote resistance 3
• Do not assume this is musculoskeletal back pain—the radiation to the abdomen and relief with leaning forward are pathognomonic for pancreatic pathology, not spinal disease 1, 2

When This Is NOT Pancreatitis

If lipase/amylase are normal and imaging is unremarkable, reconsider:

• Thoracic spine pathology with referred pain (though relief with leaning forward is atypical) 4
• Peptic ulcer disease with posterior penetration
• Renal pathology (though pain pattern differs)

However, meeting two of three criteria (typical pain, elevated enzymes >3x normal, or characteristic imaging) confirms pancreatitis 2, making alternative diagnoses unlikely in this clinical context.