4.4 Common Traps in Trauma

4.4 Abdominal, Pelvic, and Extremity Trauma

These injuries hide blood. The abdomen and pelvis can each conceal liters of hemorrhage with little external sign, so the common trap is underestimating shock because 'there is no obvious bleeding.' The paramedic's role is recognition, hemorrhage control where possible, splinting/binding to limit movement and bleeding, and rapid transport.

Abdominal trauma is blunt (solid organs — spleen, liver — rupture and bleed; the spleen is the most commonly injured in blunt trauma) or penetrating (hollow viscus perforation plus bleeding). Findings include distension, rigidity, guarding, rebound tenderness, and signs of shock. Field care is supportive: airway/oxygen, treat shock, and do not delay transport trying to diagnose the organ. Impaled objects in the abdomen (or anywhere except the cheek/airway) are stabilized in place, never removed.

Eviscerations and impaled objects

For an abdominal evisceration (protruding bowel/organs):

1. Do not push the organs back into the abdomen.
2. Cover with a moist, sterile dressing (saline-soaked gauze) to prevent drying.
3. Apply an occlusive layer over the moist dressing to retain warmth and moisture.
4. Keep the patient supine with knees flexed if tolerated to reduce abdominal tension, and keep warm to fight the lethal triad.

Impaled objects are manually stabilized and immobilized in place with bulky dressings; removal can trigger uncontrolled hemorrhage because the object may be tamponading a vessel. Exceptions where removal is acceptable: objects through the cheek that obstruct the airway, or objects that prevent chest compressions in cardiac arrest.

Document the mechanism carefully — a knife stab gives a different injury map than a high-speed deceleration, which shears solid-organ pedicles and the aorta. Penetrating injuries between the nipple line and the umbilicus may involve both chest and abdomen (the diaphragm rises during expiration), so assess both cavities. Throughout, the abdomen is a place where shock can be occult: a soft early abdomen does not exclude major bleeding, and serial reassessment of vitals and mentation matters more than palpation alone.

Pelvic fractures and binders

An unstable pelvic fracture (especially open-book/lateral-compression patterns) can cause massive, life-threatening venous and arterial hemorrhage into the pelvic space with few external signs. Suspect it with significant mechanism plus pelvic pain/instability, leg-length discrepancy, or shock without an obvious source. Do not 'rock' the pelvis repeatedly to test stability — one gentle assessment at most, because movement disrupts forming clots.

Apply a pelvic binder to close the pelvic ring and tamponade bleeding. The high-yield trap: position it at the level of the greater trochanters (the bony prominences at the hips), not the iliac crests or the waist — too high and it fails to compress the ring. Commercial binders or a folded sheet both work. Combine with shock management, permissive-hypotension principles (if no TBI), TXA, and rapid transport.

Extremity trauma, splinting, and crush

Splinting limits movement, reduces pain and bleeding, and prevents converting a closed fracture to an open one. Core rules:

• Assess and document distal pulses, motor function, and sensation (PMS) before and after splinting; loss of distal pulse after splinting means loosen/realign.
• Splint in the position found if distal circulation is intact.
• For a deformed, pulseless extremity, apply gentle longitudinal traction to realign and restore distal perfusion before splinting.
• A traction splint is for isolated mid-shaft femur fractures (contraindicated with pelvic fracture, knee/joint injury, or lower-leg/ankle fracture).
• Control extremity hemorrhage with direct pressure, then a tourniquet (4.1) for uncontrolled life-threatening bleeding.

Crush syndrome: a limb compressed for a prolonged period accumulates potassium, myoglobin, and lactic acid. On release, these flood the circulation, risking hyperkalemic cardiac arrest, acidosis, and myoglobinuric renal failure. Anticipate it: establish IV access and run fluids before extrication/release when feasible, monitor the ECG for peaked T-waves and widening QRS, and coordinate care with medical control. The trap is freeing a long-entrapped limb without preparing for the sudden metabolic insult.

Worked scenario and exam traps

A construction worker is pinned under collapsed scaffolding, one leg trapped for 90 minutes. Before lifting the load, the crew establishes IV access and begins crystalloid, places the patient on the cardiac monitor, and watches for peaked T-waves as a sign of hyperkalemia. Only then is the limb released, with continued fluids and monitoring en route. Separately, a fall victim has a midshaft femur deformity with an intact distal pulse: apply a traction splint, then recheck distal PMS. If the same patient also had a pelvic fracture, a traction splint would be contraindicated.

High-yield traps:

• Failing to check distal PMS before and after splinting — a splint that abolishes the distal pulse must be loosened or the limb realigned.
• Repeatedly rocking the pelvis to test stability — one gentle check at most; movement disrupts clots in a bleeding pelvis.
• Pelvic binder too high (iliac crests/waist) instead of at the greater trochanters — it fails to close the ring.
• Pushing eviscerated organs back in or letting them dry — use a moist sterile dressing then an occlusive cover.
• Removing impaled objects — stabilize in place (except cheek/airway-obstructing objects), because the object may be tamponading a vessel.
• Releasing a crushed limb without fluids/monitoring — anticipate the hyperkalemic surge.