Define Abdominal Trauma. Describe its investigations and management.

The Concept — the Hidden Bleeder

The abdomen is one of the great 'hidden' sites of major haemorrhage: a trauma patient can be in profound hypovolaemic shock from bleeding into the abdomen with no external sign at all. The central clinical decision in abdominal trauma is deceptively simple to state — does this patient need a laparotomy, and how urgently? — and answering it depends chiefly on the patient's haemodynamic stability.

Mechanisms & the Organs at Risk

Blunt trauma (road-traffic accidents, falls, assault) most often injures the solid organs — the spleen and liver — which bleed. Penetrating trauma divides into stab wounds (relatively predictable tracks; liver and small bowel commonly injured) and gunshot wounds (unpredictable, more destructive, usually requiring exploration). Recognising the mechanism predicts the likely injuries.

Clinical Assessment

Abdominal signs can be subtle or masked (by head injury, intoxication or distracting injuries), so a high index of suspicion is vital. Look for abdominal pain, distension, guarding or rigidity, the imprint of a seat-belt ('seat-belt sign'), bruising, and referred pain to the shoulder tip (from diaphragmatic irritation by blood). Because signs evolve, serial examination is important.

Investigations — Matched to Stability

• Fast scan (Focused Assessment with Sonography in Trauma) — a rapid bedside ultrasound that detects free fluid (blood) around the organs and heart; ideal in the unstable patient because it is immediate and does not require moving them.
• CT of the abdomen — the investigation of choice in the stable patient; it grades solid-organ injury precisely and detects other injuries, allowing non-operative management.
• Diagnostic peritoneal lavage — now largely replaced by fast and CT.

Management — Decided BY Stability

The management flows directly from the patient's physiology:

• Haemodynamically unstable with a positive fast → immediate laparotomy; do not delay for a CT scan.
• Haemodynamically stable → CT, after which many solid-organ (spleen/liver) injuries are managed non-operatively (close observation, sometimes with angiographic embolisation), preserving the organ.
• Penetrating trauma with evisceration, peritonitis or instability → laparotomy; most gunshot wounds are explored.
• In the exsanguinating patient, damage-control surgery is used — rapidly stop the bleeding and contamination, pack the abdomen, close temporarily, resuscitate and rewarm in intensive care, and return for definitive surgery once physiology is restored.

Pelvic & Retroperitoneal Haemorrhage

Two 'hidden' sites deserve special mention because they cause exsanguination that a laparotomy does not directly control. A major pelvic fracture can bleed massively into the retroperitoneum from the rich venous plexus and cancellous bone; the first-line manoeuvre is a pelvic binder to close the pelvic ring and tamponade the bleeding, followed by angiographic embolisation or surgical packing. Retroperitoneal haematoma from renal or vascular injury behaves similarly — bleeding that is concealed from both external view and simple examination.

Patterns of Organ Injury

Knowing which organ is likely injured guides the search. The spleen is the most commonly injured organ in blunt trauma (left upper quadrant pain, referred left shoulder-tip pain — Kehr's sign) and is graded on CT. The liver is next and, like the spleen, is often managed non-operatively if stable. Hollow-viscus (bowel) injury is easily missed and presents later with peritonitis; the duodenum and pancreas are injured in handlebar/seat-belt injuries; and bladder or urethral injury is suggested by blood at the urethral meatus, a high-riding prostate or inability to pass urine — a contraindication to blind catheterisation.

Serial Assessment & the Missed Injury

Because abdominal signs evolve and imaging is imperfect, the haemodynamically stable but suspicious patient is admitted for serial examination rather than discharged. A rising pulse, developing peritonism or a falling haemoglobin over the following hours may be the first sign of a bowel injury or delayed splenic rupture — the reason a single normal examination is never taken as final.

Signs That Should Raise Alarm

Certain findings flag serious intra-abdominal injury and mandate close monitoring or surgery. Peritonism (guarding, rigidity, rebound tenderness) indicates hollow-viscus perforation or significant bleeding; abdominal distension with shock suggests major intra-abdominal haemorrhage; a seat-belt sign across the abdomen is associated with bowel and mesenteric injury; and bruising in the flanks (Grey-Turner's) or around the umbilicus (Cullen's) suggests retroperitoneal bleeding. In penetrating trauma, evisceration of bowel or omentum, or an implement in situ (which is left in place until theatre) are clear indications for exploration.

Haemodynamic stability decides between CT and immediate laparotomy.

• The abdomen is a hidden site of major haemorrhage; the key question is whether a laparotomy is needed, decided mainly by haemodynamic stability.
• Blunt trauma → solid organs (spleen, liver) bleed; penetrating → stab (liver/bowel) or gunshot (explore).
• Signs may be subtle: pain, distension, guarding, seat-belt sign, shoulder-tip pain; examine serially.
• Unstable + positive fast → immediate laparotomy (no CT); stable → CT, then often non-operative management (± embolisation).
• Exsanguinating patient → damage-control surgery (stop bleeding/contamination, pack, resuscitate, definitive surgery later).