ICU · Renal/Metabolic

Rhabdomyolysis in the ICU

Also known as Rhabdomyolysis · Myoglobinuria · Crush syndrome · CK elevation

Rhabdomyolysis is breakdown of skeletal muscle releasing intracellular contents (myoglobin, creatine kinase, potassium, phosphate) into the circulation. Causes: trauma/crush, prolonged immobility, seizures, drugs and toxins (in one 475-patient cohort toxins caused 46% of cases, with illicit drugs, alcohol and prescribed drugs leading and statins among the most frequently implicated), infections (viral and bacterial), electrolyte disturbance, endocrinopathies, malignant hyperthermia, NMS, exertion. Presents with the classic triad of muscle pain, weakness and dark urine — although over half of patients do not complain of pain or weakness. Diagnosis rests essentially on CK (over 5x ULN or over 1000 IU/L; values may reach 100,000 IU/L); urine myoglobin is positive in only about a fifth of cases. Complications: AKI (acute tubular necrosis from myoglobin obstruction — 51% of one severe series at CK at or above 5000 U/L), hyperkalaemia (13% of severe cases at 5.5 mmol/L or above), hypocalcaemia (41% at 2.00 mmol/L or below) with rebound hypercalcaemia in recovery, compartment syndrome. Treatment: early aggressive IV fluid — 1.5-2 L of saline pre-hospital then 1.5-2 L/h, or about 400 mL/h in hospital, scaled to 12 L or more per day in severe crush; prefer lactated Ringer's to 0.9% saline; IV calcium reserved for hyperkalaemic ECG changes or potassium at or above 6.5 mmol/L; fasciotomy when the delta pressure (diastolic minus compartment pressure) falls under 30 mmHg.

Checked against its sources on 2 Sept 2026