A 32-year-old man is brought to the emergency department following a motor vehicle collision. He was the restrained driver. On arrival, his vital signs are: BP 110/70 mmHg, HR 118/min, RR 22/min, GCS 15. Abdominal examination reveals mild left-sided tenderness with no obvious distension. A FAST scan is performed and shows free fluid in the left paracolic gutter and pelvis. The patient remains hemodynamically stable after 2 liters of crystalloid infusion. Repeat vitals: BP 112/72 mmHg, HR 110/min. What is the most appropriate next step in management?

Explanation

## Clinical Context This patient has a **positive FAST examination** (free fluid in left paracolic gutter and pelvis) with **blunt abdominal trauma**, but remains **hemodynamically stable** after fluid resuscitation. ## Indications for Emergency Laparotomy vs. Observation | Finding | Hemodynamically Stable | Hemodynamically Unstable | |---------|------------------------|-------------------------| | Positive FAST | CT imaging + observation | Emergency laparotomy | | Peritoneal signs | Consider laparotomy | Emergency laparotomy | | Serial exam deterioration | Laparotomy | Laparotomy | **Key Point:** In a hemodynamically stable patient with a positive FAST, the **standard of care is CT abdomen/pelvis with IV contrast** to grade the solid organ injury and guide conservative vs. operative management. This is the **selective non-operative management (SNOM)** approach. **High-Yield:** FAST is a screening tool with high sensitivity (~95%) for free intraperitoneal fluid but **does NOT grade organ injury or identify the source**. CT is required for injury severity assessment and treatment planning. **Clinical Pearl:** Hemodynamic stability is the **key decision point**. A stable patient with positive FAST warrants imaging and ICU-level observation with serial abdominal exams. Deterioration (increasing HR, dropping BP, peritoneal signs) mandates immediate laparotomy. ## Why Observation Works Here - HR 118 → 110 (improving trend) - BP stable at 110–112 mmHg - No peritoneal signs (only mild tenderness) - Responds to fluid resuscitation [cite:ATLS 10th Edition Ch 5]