When to Admit Rhabdomyolysis
Admit all patients with rhabdomyolysis who have evidence of acute kidney injury, severe electrolyte abnormalities (particularly hyperkalemia), inability to maintain adequate oral hydration, or a McMahon score indicating high risk for complications.
Risk Stratification for Admission
The decision to admit hinges on identifying patients at risk for serious complications, particularly acute kidney injury (AKI). Use the following algorithmic approach:
Immediate Admission Criteria
Admit to hospital if ANY of the following are present:
- Acute kidney injury - Serum creatinine >1.3 mg/dL or rising creatinine 1
- Severe hyperkalemia - Requires immediate monitoring and potential intervention 1
- Inability to maintain oral hydration - Patient cannot drink adequate fluids (>3L/day target)
- Severe rhabdomyolysis - CPK >15,000 IU/L in trauma/crush injury contexts 1
- Altered mental status or severe symptoms - Confusion, severe weakness, or inability to ambulate
- Compartment syndrome risk factors - Crush injury, limb trauma, or clinical signs (pain, tension, paresthesia, paresis) 1
Consider ICU Admission if:
- Altered consciousness
- Severe acute kidney injury with oliguria/anuria
- Life-threatening hyperkalemia or other electrolyte derangements
- Hemodynamic instability
- Need for renal replacement therapy 2
Outpatient Management Considerations
Low-risk patients may be considered for outpatient or hospital-at-home management if ALL of the following criteria are met 3:
- Normal baseline creatinine (<1.3 mg/dL) and stable renal function
- No significant electrolyte abnormalities
- Able to maintain aggressive oral hydration (>3L/day)
- Reliable patient with access to early outpatient follow-up
- No risk factors for complications (no compartment syndrome, no severe trauma)
- Exertional etiology in otherwise healthy individual
Key Clinical Pitfalls
Important caveats to avoid:
Don't rely on CPK levels alone for admission decisions - Studies show patients with CPK >1000 U/L and normal creatinine who receive prompt fluid resuscitation rarely develop renal insufficiency 4. However, higher CPK levels (>15,000-20,000 IU/L) warrant closer monitoring 1, 3.
Monitor for delayed AKI - Patients who develop AKI often had longer time to initiate volume resuscitation 1. Early aggressive hydration is critical.
Beware of compartment syndrome - In trauma-related rhabdomyolysis, monitor every 30-60 minutes during the first 24 hours for pain, tension, paresthesia, or paresis 1.
Young, healthy patients with exertional rhabdomyolysis (e.g., spin-induced) have very low complication rates and may be suitable for hospital-at-home programs with proper monitoring 3.
Monitoring During Hospitalization
Once admitted, patients require:
- Repeated biochemical assessment: CPK, myoglobin, potassium, creatinine 1
- Hourly urine output monitoring via bladder catheterization
- Urine pH monitoring - maintain pH ≥6.5 1
- Aggressive IV crystalloid resuscitation - typically 3-6L/day, avoiding potassium-containing solutions 1, 2
Discharge Criteria
Patients can be discharged when:
- CPK levels are downtrending (most patients discharged after downtrend begins) 5
- Renal function stable or improving
- Electrolytes normalized
- Patient able to maintain adequate oral hydration
- No evidence of compartment syndrome or other complications
The average length of stay is 3-4 days, with longer stays correlating with higher peak CPK levels 5, 3.