Blunt Trauma Abdomen (BTA) – Intestinal Injury (Small & Large Bowel)

1. EPIDEMIOLOGY & SIGNIFICANCE

• Occurs in 5–15% of blunt abdominal trauma
• Often missed initially → delayed diagnosis → ↑ mortality (up to 20–30%)
• Common mechanisms:
• Road traffic accidents (most common)
• Seat-belt injury (classic)
• Assault / fall
  # Intestinal injuries are second most commonly missed intra-abdominal injury after pancreatic trauma.

2. MECHANISM OF INJURY

A. Compression Injury

• Bowel crushed between:
• Anterior abdominal wall
• Vertebral column
• Leads to:
• Contusion
• Intramural hematoma
• Perforation

B. Deceleration Injury

• Sudden stop → shearing at fixed points
• Ligament of Treitz
• Ileocecal junction
• Causes:
• Mesenteric tear
• Bowel ischemia → delayed perforation

C. Burst Injury

• Sudden ↑ intraluminal pressure
• Typical:
• Closed-loop obstruction + blunt force
• Leads to:
• Blow-out perforation

3. PATHOPHYSIOLOGY

Sequence:

1. Mechanical injury → mucosal disruption
2. Bacterial translocation
3. Peritoneal contamination
4. Systemic inflammatory response → sepsis

 Delayed perforation:

• Due to:
• Mesenteric ischemia
• Progressive necrosis

4. COMMON SITES OF INJURY

Small intestine (most common)

• Jejunum > Ileum
• Near fixed points (Treitz, ileocecal region)

Duodenum

• Retroperitoneal → subtle presentation
• Common in:
• Handlebar injury

Colon

• Less common but:
• More contamination → worse outcomes

 5. CLINICAL FEATURES

A. Early (Often subtle)

• Mild abdominal pain
• Nausea / vomiting
• Minimal tenderness

B. Classic signs (Late)

• Guarding, rigidity
• Rebound tenderness
• Abdominal distension
• Fever

C. Important clues

• Seatbelt sign → high suspicion
• Unexplained tachycardia
• Leukocytosis
• Metabolic acidosis

 Key concept:
 Normal initial exam DOES NOT exclude bowel injury

6. DIAGNOSTIC APPROACH

A. FAST (E-FAST)

• Detects:
• Free fluid
• Limitation:
• Cannot detect bowel injury directly

B. CT Scan (Gold Standard in Stable Patients)

CT Findings

🔴 Hard Signs (Indication for surgery)

• Pneumoperitoneum (free air)
• Contrast extravasation
• Bowel wall discontinuity

🟡 Soft Signs (Need close monitoring / repeat CT)

• Bowel wall thickening
• Mesenteric stranding
• Mesenteric hematoma
• Free fluid WITHOUT solid organ injury

C. Diagnostic Peritoneal Lavage (DPL)

• Rarely used now
• Positive if:
• Bile
• Food particles
• Bacteria

D. Serial Examination (VERY IMPORTANT)

• Repeat exam every 4–6 hours
• Repeat CT if suspicion persists

 7. AAST GRADING (Small Bowel Injury)

 8. MANAGEMENT 

A. Indications for Immediate Surgery

• Hemodynamic instability
• Peritonitis
• CT “hard signs”
• Evisceration

 B. Non-operative Management (Selected cases)

• Hemodynamically stable
• No peritonitis
• Only soft CT signs

Includes:

• ICU monitoring
• Serial exams
• Repeat imaging

 C. Operative Management

1. Primary repair

• Small perforations
• Minimal contamination

2. Resection + anastomosis

• Non-viable bowel
• Large injuries

3. Stoma (damage control)

• Hemodynamic instability
• Gross contamination
• Delayed presentation

 9. DAMAGE CONTROL SURGERY (DCS)

Indications:

• Acidosis (pH <7.2)
• Hypothermia
• Coagulopathy

Steps:

1. Control contamination
2. Staple bowel ends
3. Temporary abdominal closure
4. ICU resuscitation → second look surgery

 10. ICU MANAGEMENT

A. Resuscitation

• Balanced crystalloids
• Blood products (1:1:1 strategy if massive transfusion)

B. Antibiotics 

• Early broad-spectrum:
• Piperacillin-tazobactam OR carbapenem
• Cover:
• Gram-negative + anaerobes

C. Monitoring

• Lactate
• Abdominal exam
• Drain output

 11. COMPLICATIONS

Early

• Peritonitis
• Sepsis
• Intra-abdominal abscess

Late

• Adhesions → obstruction
• Enterocutaneous fistula