Crush Syndrome
Objective: Treat a long crush as a high-potassium and muscle-breakdown problem. Start fluid before or as you lift, when protocol allows. If the ECG goes wide after release, think calcium per protocol.
Why this matters
The limb can look quiet under the weight. When you lift it, potassium, muscle protein, and acid enter the blood. Sudden pulseless electrical activity (PEA) after extrication is a classic crush death. The dangerous moment is release, not the look of the limb.
Start intravenous fluid before full release when you can, or as soon as you have access. Do not use fluid that contains potassium. Treat high potassium when the ECG shows it. See the hyperkalemia lesson. Your protocol owns the rate. This site does not publish a milliliter-per-kilogram recipe.
- Ask how long the patient has been trapped. Hours matter. Entrapment of only a few minutes is a different problem.
- Get access and start fluid before the full lift when the scene allows it.
- Do not hang fluid that contains potassium. If your protocol names normal saline for crush, use that.
- After release, keep the monitor on. Peaked T waves or a wide QRS means calcium per protocol, for membrane stabilization.
- How long have they been trapped?
- Access and fluid before the full lift, when we can.
- No potassium in the fluid bag.
- After release, peaked T waves or a wide QRS means calcium per protocol.
Who Is at Risk
- Prolonged compression of a large muscle mass. Think hours, not a four-minute entrapment. Building collapse, a vehicle crash, industry, earthquake, or a person found lying on a limb.
- The trapped limb may not hurt much. That does not mean it is safe to lift and leave.
Clinical sequence
- Make the scene safe. You cannot resuscitate under a wall that is still moving.
- Open the airway, support breathing, stop bleeding, and give oxygen. Get an IV or IO as soon as it is realistic. That is often before technical rescue is finished.
- Give isotonic fluid per protocol, preferably normal saline, as early as you can and before the full lift when the scene allows it. NAEMSP teaching supports large-volume crystalloid in that window. Your protocol owns the rate. This site does not publish a milliliter-per-kilogram recipe.
- Coordinate the lift with the rescue team. Tell them the patient may lose pulses when the weight comes off.
- After release, get a 12-lead and watch the monitor. Treat ECG signs of high potassium with calcium per protocol. Use albuterol to shift potassium only if your protocol allows it. Treat pain. If the patient is very sick, go to a hospital that can dialyze.
- A tourniquet placed only to prevent crush syndrome is a medical-direction decision for prolonged entrapment. Do not invent that move on a short entrapment of about 15 to 20 minutes.
Do Not
- Hang potassium-containing maintenance fluid as the crush bag.
- Do not treat wide-complex PEA after the lift as ordinary ventricular tachycardia and reach for amiodarone first. Think high potassium until proven otherwise. Start CPR and use protocol calcium for membrane stabilization.
- Forget later muscle breakdown. Dark urine is a hospital problem. Name it in the handoff.
Common errors
- No monitor after a multi-hour extrication.
- Waiting for the hospital to start fluid when you already had a line for an hour.
Practice
One-minute check
A leg has been under a forklift for 4 hours. The patient is alert, then goes into PEA 2 minutes after the lift. Name what entered the blood. Name the first arrest drug class to think about. Name one fluid you will not use.
Related: Hyperkalemia ECG Recognition, PEA, Traumatic Arrest.
Sources & Further Study
Named guidelines for further study. They are not clinical orders and do not replace your protocol or medical direction.
- NASEMSO National Model EMS Clinical Guidelines (2022) — U.S. EMS model language; your protocol decides
- NAEMSP 2024 Prehospital Trauma Compendium: crush / entrapment — start isotonic crystalloid (preferably normal saline) as early as possible and before extrication when you can; avoid potassium-containing fluids; hyperkalemia meds and a tourniquet-before-lift are protocol decisions
- AHA 2025 Part 10: Special Circumstances — hyperkalemia as a reversible arrest cause
- Protocol owns fluid type, rate, tourniquet-before-lift, and dialysis destination. This site does not publish a formula.
Education only. Apply learning within your protocols and medical direction. This is not clinical care guidance.
Check Your Understanding
Questions drawn only from this lesson. After you check, the key is highlighted. Education practice — not a certification exam.