A 28-year-old woman is brought to the trauma bay following a stab wound to the left lower chest (6th intercostal space, mid-axillary line). On arrival: BP 96/62 mmHg, HR 118 bpm, RR 22/min, and she is alert but anxious. Breath sounds are present bilaterally. Abdominal examination reveals mild left-sided tenderness but no peritoneal signs. A FAST scan shows a small amount of free fluid in the left paracolic gutter. After 1 L of crystalloid, her BP improves to 104/68 mmHg and HR decreases to 102 bpm. What is the most appropriate management strategy?

Explanation

## Clinical Context This patient presents with a **penetrating thoracoabdominal wound** (6th ICS, mid-axillary line—below the diaphragm) with **Class II hemorrhagic shock** (BP 96/62, HR 118) that **responds to initial crystalloid** (BP improves to 104/68, HR decreases to 102). FAST shows free fluid but she is hemodynamically stable after resuscitation. ## Why Observation with Serial Examination is Correct **Key Point:** A **responding patient** with penetrating trauma and hemodynamic improvement after initial resuscitation can be managed non-operatively with close monitoring, provided there are no peritoneal signs or ongoing hemorrhage. **High-Yield:** The **ATLS classification** distinguishes: - **Non-responders** (persistent shock despite 2 L crystalloid) → immediate OR - **Transient responders** (improve initially but may deteriorate) → close observation ± imaging - **Responders** (stable after initial resuscitation) → selective non-operative management (SON) This patient is a **responder**. Management includes: 1. **Admission to high-dependency unit** for continuous monitoring 2. **Serial clinical examination** (abdominal tenderness, distension, peritoneal signs) 3. **Serial hemoglobin** (trend indicates ongoing bleeding) 4. **Repeat imaging** (CT or FAST) if clinical deterioration occurs 5. **Low threshold for laparotomy** if signs of peritonitis, shock, or falling hemoglobin develop **Clinical Pearl:** The presence of free fluid on FAST does NOT automatically mandate surgery in a stable, responding patient. Free fluid may be blood that has self-limited or a small amount that does not require operative intervention. **Clinical stability and response to resuscitation** are the key decision drivers. **Mnemonic: SAM** (Stable, Admit, Monitor)—the approach for responders with penetrating trauma. ## Why Immediate Laparotomy is Wrong Laparotomy is indicated for **non-responders** or patients with **peritoneal signs**. This patient is hemodynamically stable after resuscitation and has only mild tenderness—not an acute indication for surgery. ## Why Discharge is Dangerous Discharging a patient with penetrating trauma and documented free fluid on FAST risks delayed presentation with hemorrhagic shock or peritonitis. These patients require **admission and monitoring**.