12.4 Pelvic, Crush, and Extremity Trauma

An unstable pelvis can empty the tank into a space focused assessment with sonography for trauma (FAST) cannot see, and a traction splint that fit the ambulance may not fit the aircraft. Domain 3.F of the August 2026 Board of Certification for Emergency Nursing (BCEN) Certified Flight Registered Nurse (CFRN) outline tests musculoskeletal trauma—pelvic, crush, and extremity injuries—because packaging is treatment. Burns are Chapter 13. Bleeding physiology is Chapters 8 and 10: blood, warmth, and the trauma diamond, not another liter of cold salt water into a widening pelvic ring.

Unstable pelvis: bind it, do not rock it

If the pelvic ring is mechanically unstable or the mechanism plus shock says pelvis, apply a commercial pelvic binder or a sheet wrap over the greater trochanters, then internally rotate the legs and tape them. A binder high on the iliac crests does not close the ring and can worsen pain without reducing volume. Do not rock the pelvis repeatedly. Springing the ring to decide whether it is loose disrupts clot you cannot replace in a helicopter.

Open-book versus vertical shear, conceptually

Think in volumes, not radiology reports you do not have.

You will not classify these on a dirt road. You will bind, stop the exam that wiggles the clot, start blood (Chapter 8), and fly to a center that can pack, fix, or embolize (section 12.3). A binder is not a reason to skip tranexamic acid or product if the rest of the hemorrhage protocol applies (Chapter 10 hemostasis).

Crush, rhabdomyolysis, and tourniquets

A crushed limb that is freed after prolonged entrapment dumps potassium, acid, and myoglobin into a circulation that may already be dry. Traumatic rhabdomyolysis is dark urine, rising creatine kinase (CK) if you have a cartridge, and hyperkalemia that can arrest the patient after extrication. Unlike uncontrolled torso hemorrhage, this is a time to give crystalloid to protect the kidneys—program rates vary; the exam idea is volume for the crush, not permissive hypotension copied blindly from a pelvic bleeder. Watch the electrocardiogram (ECG) for peaked T waves, a widening QRS, and bradycardia. Treat hyperkalemia per protocol (calcium to stabilize membrane, then shift and remove).

Tourniquet decisions are written, not improvised. Some crush protocols leave a tourniquet on the destroyed limb until a receiving team can control reperfusion; others release under monitoring. Follow the program. A tourniquet on a salvageable limb that is simply swollen is not automatic. A tourniquet on a stump that is pumping is mandatory.

Compartment syndrome, amputation, open fractures, cabin space

Compartment syndrome is rising pressure in a fascial box. The earliest useful finding is pain out of proportion and pain on passive stretch. The six Ps are a teaching list, not a checklist you wait to complete:

• Pain (early, out of proportion, worse with passive stretch)
• Paresthesia
• Pallor
• Paralysis (late)
• Poikilothermia (the limb is cold)
• Pulselessness (late—do not wait for it)

A pulse does not clear the compartment. Vibration and a vacuum mattress hide the exam; recheck after every move. In flight you cannot perform a fasciotomy unless that is a rare, protocol-defined skill. You can loosen circumferential dressings and splints, keep the limb at heart level rather than a high elevate that starves perfusion, treat pain, and warn the receiving surgeon.

A complete amputation is a hemorrhage-first problem. Tourniquet the stump. Bag the part: rinse gross dirt, wrap in saline-moist gauze, place it in a sealed bag, then put that bag on ice. Cool, do not freeze. Direct ice, dry ice, or a part floating in water ruins tissue. Fly the patient and the part to a replantation-capable center when the rest of the injuries allow; life before limb if the pelvis or abdomen is still open.

Open fractures get a sterile or clean cover, not a deep rural exploration. Give antibiotics when the protocol stocks them—often a first-generation cephalosporin such as cefazolin, with broader coverage per program for heavy contamination. That drug list is clinical teaching, not a BCEN formulary. Align and splint. Recheck pulse, motor, and sensation after every transfer.

A mid-shaft femur loves a traction splint (Hare, Sager) on the ground. In a tight rotor-wing cabin the same device can block the door, foul the litter locks, or prevent access to a pelvic binder and femoral intraosseous (IO) site. Traction is not mandatory for every femur in flight. If the splint will not fit or it fights the binder, secure the limb in the long axis of the patient—vacuum mattress, board, or pillow-and-tape—and treat blood loss as a femoral and pelvic problem (Chapters 8 and 10). Traction is relatively contraindicated with an unstable pelvis, a disrupted knee, or an amputation through the field you would pull against.