A 45-year-old woman with no prior abdominal surgery presents with acute periumbilical pain and vomiting. Plain abdominal radiograph shows multiple dilated small bowel loops with air-fluid levels in a stepladder pattern, and no free air. What is the most appropriate immediate next step in management?

Explanation

## Clinical Presentation & Radiographic Findings The patient presents with: - **Acute small bowel obstruction** (dilated loops, air-fluid levels, stepladder pattern) - **No free air** (no perforation) - **No prior surgery** (rules out adhesions as the primary etiology, but adhesions can still occur) ## Management Strategy for Uncomplicated Small Bowel Obstruction **Key Point:** The majority of small bowel obstructions (60–80%) resolve with conservative management (nasogastric decompression and supportive care). Surgery is reserved for: - Signs of peritonitis or perforation - Failed conservative management (typically after 48–72 hours) - Strangulation (clinical deterioration, fever, leukocytosis) ### Immediate Management Protocol 1. **Nasogastric tube insertion** — decompresses proximal bowel, relieves distension and vomiting 2. **IV fluid resuscitation** — corrects hypovolemia and electrolyte losses 3. **Electrolyte correction** — replace K^+^, Na^+^, Cl^−^ losses from vomiting 4. **Serial clinical examination** — assess for signs of strangulation or perforation 5. **Repeat imaging at 24–48 hours** — if no improvement, escalate to CT or surgery **Clinical Pearl:** The absence of free air and the patient's relatively stable presentation (no mention of fever, severe peritonitis, or hemodynamic instability) favor a trial of conservative management. Most uncomplicated obstructions resolve within 48–72 hours with NG decompression alone. **High-Yield:** "Stepladder" pattern of air-fluid levels is classic for small bowel obstruction. When there is no free air and no peritoneal signs, conservative management is the standard of care. ### Why Not Proceed Directly to Surgery? Immediate laparotomy is reserved for: - Peritonitis or perforation (free air) - Signs of strangulation (fever, severe pain, leukocytosis, hemodynamic instability) - Failed conservative management Unnecessary surgery in uncomplicated obstruction increases morbidity and mortality from adhesions and infection. ### Role of CT in This Context CT is useful for: - **Identifying the cause** (hernia, malignancy, stricture) if conservative management fails - **Assessing for strangulation** (wall thickening, mesenteric edema, free fluid) - **Guiding surgical planning** if intervention becomes necessary However, CT is **not the immediate next step** in uncomplicated obstruction; it is reserved for cases that fail conservative management or show signs of complications. ```mermaid flowchart TD A["Small bowel obstruction on plain film"]:::outcome --> B{"Signs of perforation or peritonitis?"}:::decision B -->|"Yes: Free air or peritoneal signs"| C["Emergency laparotomy"]:::urgent B -->|"No"| D["NG tube + IV fluids + electrolyte correction"]:::action D --> E["Serial clinical exam every 4–6 hours"]:::action E --> F{"Improvement at 24–48 hours?"}:::decision F -->|"Yes: Resolving"| G["Continue conservative management"]:::action F -->|"No: Persistent or worsening"| H["CT abdomen to assess cause and viability"]:::action H --> I{"Strangulation or irreducible cause?"}:::decision I -->|"Yes"| J["Surgical intervention"]:::action I -->|"No"| K["Continue NG decompression, reassess"]:::action ```