Rhabdomyolysis is the breakdown of skeletal muscle that releases myoglobin, potassium and other cell contents into the blood. Common causes are crush injury, extreme exercise, long immobility, drugs and heat, and the main dangers are kidney injury and high potassium.
Key symptoms
- Muscle pain, weakness and swelling
- Dark, tea-colored urine
- Fatigue, nausea and fever
- History of a fall with a long time on the floor, intense exercise or drug use
What you find on exam
- Tender, swollen muscles
- Signs of dehydration
- Tense compartment with pain on passive stretch
- Pressure marks or skin changes from lying still
Tests
- Creatine kinase (CK), usually above 5 times the upper limit of normal
- Urinalysis: dipstick positive for blood with few or no red cells
- Potassium, calcium, phosphate and creatinine
- ECG for hyperkalemia; drug screen as needed
Treatment basics
- Early, generous IV fluids with isotonic saline
- Target urine output of about 200 to 300 mL per hour
- Treat high potassium urgently
- Stop causative drugs and treat the cause
- Dialysis for severe kidney injury; fasciotomy for compartment syndrome
Red flags
- High potassium or ECG changes
- Falling urine output or rising creatinine
- Compartment syndrome: severe pain and a tense limb
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; NASEMSO National Model EMS Clinical Guidelines. Written by Making Synapses. Making Synapses is not affiliated with these organizations.