A 45-year-old woman with no prior abdominal surgery presents to the emergency department with acute onset severe epigastric pain radiating to the back, followed by sudden onset of severe diffuse abdominal pain and rigidity. On examination, she is in severe distress with board-like abdominal rigidity and rebound tenderness. Upright chest radiograph shows free air under the diaphragm. Serum lipase is elevated at 450 U/L. What is the most appropriate next step in management?

Explanation

## Clinical Presentation This patient presents with **perforated viscus** (most likely perforated peptic ulcer given the epigastric pain and free air). The constellation of findings is pathognomonic: - Acute severe pain with peritonitis (rigidity, rebound) - **Free air under diaphragm** on upright CXR (pneumoperitoneum) - Elevated amylase/lipase (from peritoneal irritation) - No prior surgery (excludes adhesive obstruction) ## Management of Perforated Viscus ```mermaid flowchart TD A[Acute Abdomen + Pneumoperitoneum on CXR]:::outcome --> B{Hemodynamically Stable?}:::decision B -->|Unstable: shock, severe sepsis| C[Aggressive Resuscitation]:::action C --> D[Immediate OR Prep]:::urgent B -->|Stable| E{Peritonitis Present?}:::decision E -->|Yes: rigidity, rebound, guarding| F[Surgical Consultation]:::action E -->|No: mild tenderness| G[Consider Conservative Rx]:::action F --> H[Exploratory Laparotomy]:::urgent G --> I[NG tube + IV fluids + Antibiotics]:::action I --> J[Serial Exams; Escalate if Deterioration]:::action ``` **Key Point:** Pneumoperitoneum + peritonitis = **surgical emergency**. The patient requires immediate surgical intervention. Delay increases mortality from sepsis and organ failure. **High-Yield:** Free air on plain film (upright CXR or left lateral decubitus) is pathognomonic for **perforation**. Combined with peritoneal signs, this mandates urgent surgery. **Mnemonic: PERFORATION SIGNS — SURGICAL EMERGENCY** - **P**neumoperitoneum (free air on CXR) - **E**poch of pain (acute onset) - **R**igidity (board-like abdominal wall) - **F**ever (from peritonitis) - **O**utcome: requires **O**perative intervention - **R**ebound tenderness - **A**cute distress - **T**achycardia, hypotension - **I**ncreased WBC - **O**perate immediately - **N**o time for imaging delays **Clinical Pearl:** In perforated peptic ulcer, the primary goal is source control (closure/oversewing of the perforation site). CT is unnecessary when the diagnosis is already certain from plain films and clinical signs. Delaying surgery to obtain CT increases morbidity and mortality. ## Why CT Is Not Appropriate Here CT is useful for **diagnostic uncertainty** (e.g., is there really free air? is it from perforation or other cause?). Here, the diagnosis is **certain**: free air + peritonitis = perforation. CT delays definitive management. [cite:Sabiston Textbook of Surgery Ch 44; Harrison 21e Ch 298]