A 35-year-old man is brought to the emergency department 30 minutes after a stab wound to the right lower abdomen (below the arcuate line, lateral to the rectus sheath). He is haemodynamically stable (BP 132/80 mmHg, HR 88/min). Abdominal examination shows a single stab wound with minimal bleeding, soft abdomen, no peritoneal signs, and normal bowel sounds. What is the most appropriate next step in management?

Explanation

## Penetrating Abdominal Trauma: Selective Non-Operative Management ### Clinical Context The patient is haemodynamically stable with no peritoneal signs (no guarding, rigidity, or rebound tenderness). The wound is in the **lower abdomen below the arcuate line**, which is a lower-risk zone. In such cases, **local wound exploration** is the critical next step to determine if the fascia has been violated. ### Why Local Wound Exploration? **Key Point:** Local wound exploration (LWE) under local anaesthesia is the gold standard first step in haemodynamically stable patients with penetrating abdominal wounds. It determines whether the injury is superficial (above fascia) or deep (fascia violated), which guides further management. **High-Yield:** If LWE shows: - **Fascia intact** → Safe to observe or discharge with close follow-up - **Fascia violated** → Proceed to laparotomy (even if haemodynamically stable) ### Technique of Local Wound Exploration 1. Clean the wound with antiseptic 2. Infiltrate local anaesthetic (1% lignocaine without adrenaline) 3. Gently probe the wound tract with a sterile gloved finger or probe 4. Determine if the wound penetrates the fascia 5. Assess for bleeding, CSF leakage, or visceral protrusion ### Management Decision Tree ```mermaid flowchart TD A[Penetrating abdominal wound]:::outcome --> B{Haemodynamically<br/>stable?}:::decision B -->|No| C[Immediate laparotomy]:::urgent B -->|Yes| D{Peritoneal signs<br/>present?}:::decision D -->|Yes| E[Laparotomy]:::action D -->|No| F[Local wound exploration<br/>under local anaesthesia]:::action F --> G{Fascia<br/>violated?}:::decision G -->|Yes| H[Laparotomy]:::action G -->|No| I[Observe or discharge<br/>with follow-up]:::action ``` **Clinical Pearl:** Local wound exploration is fast, inexpensive, and highly accurate (>95% sensitivity) for determining fascial penetration. It avoids unnecessary laparotomies in 30–40% of haemodynamically stable patients. ### Why This Location Matters The **lower abdomen below the arcuate line** has only peritoneum and viscera (no muscular fascia in the classical sense), making fascial exploration straightforward. Wounds in this zone that do not violate peritoneum are very unlikely to cause significant injury. [cite:Park 26e Ch 15; Advanced Trauma Life Support ATLS 10e]