Abdominal Trauma

OVERVIEW 

Abdominal trauma involves physical injury to the abdominal wall, solid organs (spleen, liver, kidneys, pancreas), hollow viscera (stomach, small/large bowel, bladder), or retroperitoneal structures caused by blunt or penetrating mechanisms.

Classification:

• Blunt Abdominal Trauma (BAT): Motor vehicle collisions, falls, direct impacts. Solid organ injury (Spleen, Liver) is most common.
• Penetrating Abdominal Trauma (PAT): Stab wounds or gunshot wounds (GSW). Hollow visceral injuries are more common in GSWs; liver and small bowel in stab wounds.

Anatomical Zones: Thoracoabdominal (4th intercostal space to costal margin), Anterior Abdomen, Flank, Back, and Retroperitoneum.

APPROACH

Step 1: Primary Survey & Hemodynamic Triage (ATLS – ABCDE)

• Airway & Breathing: Secure airway if altered or in shock; rule out concurrent chest injuries.
• Circulation: Check pulses, BP, skin perfusion. Establish two large-bore IV lines (16G or larger) or IO access. Initiate balanced resuscitation (1:1:1 packed RBCs, FFP, platelets) if unstable; avoid crystalloid overload.
• Exposure: Fully expose and inspect for seatbelt signs, grey turner/cullen signs, EVISCEREATION, peritonitis, or penetrating entry/exit wounds. Cover eviscerated bowel with warm, sterile, saline-soaked dressings (do NOT force bowel back in).

Step 2: Emergency Surgical Indications (Hard Signs for Laparotomy)

• Proceed straight to Operating Theatre for Immediate Laparotomy if:
  • Hemodynamic instability / persistent shock WITH positive FAST scan or clear intra-abdominal source.
  • Frank peritonitis on physical examination (rigid, involuntary guarding, rebound tenderness).
  • Bowel / omental evisceration.
  • Gunshot wound penetrating the peritoneal cavity.
  • Free air (pneumoperitoneum) on plain imaging.

Step 3: Clinical Decision Branching for Stable / Equivocal Patients

• Hemodynamically Unstable: Bedside FAST scan.
  • FAST Positive ->> Emergency Laparotomy.
  • FAST Negative / Equivocal ->> Look for extra-abdominal blood loss (pelvic fracture, hemothorax) or perform Diagnostic Peritoneal Lavage (DPL).
• Hemodynamically Stable:
  • Proceed to Contrast-Enhanced CT Abdomen/Pelvis (IV + oral/rectal contrast depending on protocol).

DIFFERENTIAL DIAGNOSIS

Solid Organ Injuries (Most common in Blunt Trauma):

• Splenic Injury (Most Common Overall in Blunt Trauma):
  • Distinguishing features: Left upper quadrant (LUQ) tenderness, Kehr’s sign (referred left shoulder pain due to diaphragmatic irritation), lower left rib fractures (ribs 9–11).
• Hepatic Injury (Second Most Common in Blunt Trauma, Highest Mortality):
  • Distinguishing features: Right upper quadrant (RUQ) tenderness, right lower rib fractures (ribs 9–11), hypovolemic shock; risk of late hemobilia (triad of RUQ pain, jaundice, upper GI bleed).
• Renal Injury:
  • Distinguishing features: Flank ecchymosis (Grey Turner’s sign), lower rib/lumbar transverse process fractures, gross or microscopic hematuria.
• Pancreatic Injury:
  • Distinguishing features: Epigastric pain radiating to back, delayed presentation with persistent nausea/vomiting or fever; elevated serum amylase/lipase (delayed). High incidence in bicycle handlebar injuries in children or steering wheel impacts in adults.

Hollow Viscus & Mesenteric Injuries:

• Bowel Disruption / Perforation (Small Bowel, Colon):
  • Distinguishing features: Lap seatbelt sign across abdomen; progressive peritonitis (guarding, rigidity) developing over hours due to chemical/bacterial contamination; pneumoperitoneum on CT.
• Diaphragmatic Rupture:
  • Distinguishing features: Left-sided blunt impact (80% left due to protective liver on right); chest pain, dyspnea, scaphoid abdomen, bowel sounds in left hemithorax, NG tube curling into chest on CXR.

Retroperitoneal & Vascular Injuries:

• Pelvic Fracture with Retroperitoneal Hematoma:
  • Distinguishing features: Pelvic instability on compression, perineal ecchymosis, blood at urethral meatus, high-riding prostate; massive occult blood loss.
• Major Vascular Disruption (Abdominal Aorta, IVC, Iliac Vessels):
  • Distinguishing features: Rapidly fatal hemorrhagic shock, expanding abdominal distension.

INVESTIGATIONS

First-Line / Bedside Diagnostics:

• Focused Assessment with Sonography for Trauma (FAST):
  • 4 Views: Perihepatic (RUQ/Morison’s pouch), Perisplenic (LUQ), Pelvic (Suprapubic/Pouch of Douglas), Pericardial (Subxiphoid).
  • Role: Detects intra-abdominal free fluid (blood). Highly sensitive for intraperitoneal fluid (>200 mL), but cannot differentiate blood from urine/bile and cannot grade solid organ injuries.
• Bedside Bloods: FBC, U&E, LFTs, Lipase/Amylase, Coagulation profile, Group & Crossmatch (minimum 4–6 units), ABG (Lactate & Base Deficit quantify shock severity).
• Urine Dipstick / Urinalysis: Check for gross or microscopic hematuria (renal/urinary tract injury).

Targeted / Imaging Strategy:

• Triple-Phase Contrast CT Abdomen/Pelvis (Gold Standard in STABLE Patients):
  • Evaluates exact organ injury grade (AAST grading I–V), identifies active arterial extravasation (“contrast blush”), retroperitoneal hematomas, mesenteric tears, and free air/fluid.
• Diagnostic Peritoneal Lavage (DPL) / Diagnostic Peritoneal Aspiration (DPA):
  • Role: Rarely used now; indicated in unstable patients when FAST is inconclusive or unavailable. Positive if >10 mL gross blood aspirated immediately, or lab results show >100,000 RBCs/mm3, >500 WBCs/mm3, or presence of enteric/bile contents.

CRITICAL MANAGEMENT

Non-Operative Management (NOM) for Solid Organ Injuries:

• Standard of Care for Hemodynamically Stable Patients: Grade I–V Spleen, Liver, or Kidney injuries in stable patients without peritonitis are managed non-operatively in an ICU/HDU setting (serial abdominal exams, strict bed rest, serial hemoglobin monitoring).
• Angioembolization: High success rate for stable patients with CT evidence of active arterial contrast extravasation (“contrast blush”) or pseudoaneurysm.

Damage Control Surgery (DCS):

• Indications: “Lethal Triad” of trauma (Hypothermia <35°C, Coagulopathy, Acidosis pH <7.20) during laparotomy.
• Strategy: Abbreviated initial laparotomy focusing strictly on rapid hemorrhage control (packing, vascular shunts) and contamination control (stapling bowel ends) ->> Temporary abdominal closure (vac-pack) ->> Transfer to ICU for physiological resuscitation ->> Planned re-look laparotomy in 24–48 hours.

Pelvic Fracture Hemorrhage Management:

• Immediate Stabilization: Apply Pelvic Binder / Sheet centered over the Greater Trochanters (NOT the iliac crests) to reduce pelvic volume and promote venous tamponade.