Last reviewed: March 2026
Contents
MDM Templates
Rhabdomyolysis — Mild / Exertional
Patient presents with muscle pain and darkened urine after exertion. CK is elevated. Renal function is normal. Electrolytes without life-threatening abnormalities. ECG without arrhythmia.
History, exam, and workup lower suspicion for myositis, fracture, compartment syndrome, or other emergent cause. Presentation most consistent with exertional rhabdomyolysis.
Plan: Copious oral hydration. Analgesics (avoid NSAIDs given rhabdomyolysis).
Disposition: Discharge with return precautions for decreased urine output, worsening pain, or dark urine despite hydration. Follow up with PCP within 48 hours for repeat CK and renal function.
Rhabdomyolysis — Severe / Admit
Patient presents with muscle pain, darkened urine, and significantly elevated CK. Renal function and electrolytes evaluated. ECG reviewed for hyperkalemia changes.
Given degree of CK elevation and risk for acute kidney injury and electrolyte derangements, patient requires admission for IV hydration and serial monitoring.
Plan: Aggressive IV crystalloid resuscitation targeting urine output of 2 mL/kg/hr. Foley catheter for output monitoring. Serial electrolytes and renal function. ECG monitoring for hyperkalemia.
Disposition: Admit for continued hydration and monitoring. No life-threatening arrhythmia or electrolyte abnormality at this time.
If hyperkalemia present: Calcium gluconate for cardiac membrane stabilization if ECG changes. Insulin/glucose, albuterol for potassium shifting. Kayexalate if indicated. Nephrology consulted if refractory or dialysis anticipated.
Clinical Education
Common Causes
Think beyond exertion. While exertional rhabdomyolysis (CrossFit, military training, marathon) is the most common ED presentation, other important causes include: prolonged immobilization (found down, intoxication), crush injury, seizures, sympathomimetic/PCP use, statins (especially with interacting medications), sickle cell crisis, and malignant hyperthermia. Always ask about the precipitant — it may need its own workup and treatment.[1]
CK Interpretation
CK rises 2–12 hours after injury and peaks at 24–72 hours. The degree of CK elevation correlates with the degree of muscle injury but does NOT reliably predict renal failure. Patients with CK >5,000 have increased risk for AKI, but patients with CK >40,000 and normal renal function can sometimes be managed as outpatients with aggressive oral hydration if they are clinically well.[2]
The CK number alone doesn’t determine disposition — it’s the combination of CK level, renal function, electrolytes, urine output, and the patient’s ability to hydrate that drives the decision.
Complications
Acute kidney injury is the most feared complication — myoglobin precipitates in renal tubules, especially in acidic and concentrated urine. Risk factors for AKI include CK >5,000, dehydration, acidosis, and pre-existing renal disease. Hyperkalemia is the most immediately dangerous complication — myonecrosis releases potassium directly into the circulation. Get an ECG on every rhabdomyolysis patient.[3]
Other complications: hypocalcemia (calcium binds to damaged muscle early), hyperphosphatemia, metabolic acidosis, DIC (rare), and compartment syndrome (both a cause and a complication).
Treatment
IV normal saline is the cornerstone of treatment. The goal is to dilute myoglobin in the tubules and maintain brisk urine output. Severe cases frequently need 10+ L/day initially. Target urine output of 2 mL/kg/hr (roughly 200–300 mL/hr). Place a Foley to accurately monitor output.[4]
Bicarbonate for urine alkalinization is controversial. The theory is that alkaline urine prevents myoglobin precipitation. In practice, there’s no strong evidence it improves outcomes over aggressive saline alone, and it carries risks (worsening hypocalcemia, fluid overload). Most ED physicians use isotonic saline without bicarbonate unless the patient has significant metabolic acidosis.
Avoid NSAIDs — they reduce renal blood flow and worsen the risk of AKI. Use acetaminophen or opioids for pain control.
If hyperkalemia develops: calcium gluconate for membrane stabilization if ECG changes, insulin/glucose and nebulized albuterol for acute shifting, and early nephrology consultation if potassium is refractory or rising despite treatment.
Disposition
Admit for: CK >30,000, rising CK, AKI (elevated creatinine or oliguria), significant electrolyte abnormalities (especially hyperkalemia), inability to tolerate oral hydration, ongoing muscle injury (compartment syndrome, immobilization), or uncertainty about the cause (consider occult crush injury, toxic ingestion, or NMS).[2]
Exertional rhabdomyolysis with CK <30,000, normal renal function, normal electrolytes, and adequate oral intake can often be discharged with aggressive oral hydration instructions and 48-hour lab recheck. These patients do well — exertional rhabdo has lower rates of AKI than other etiologies.
References
- Zutt R et al. Rhabdomyolysis: review of the literature. Neuromuscul Disord. 2014;24(8):651-659. PubMed
- Long B et al. An evidence-based narrative review of the emergency department evaluation and management of rhabdomyolysis. Am J Emerg Med. 2019;37(3):518-523. PubMed
- Bosch X et al. Rhabdomyolysis and acute kidney injury. N Engl J Med. 2009;361(1):62-72. PubMed
- Sauret JM et al. Rhabdomyolysis. Am Fam Physician. 2002;65(5):907-912. PubMed
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