CLINICAL PEARLS AND PITFALLS Myoglobinuria will cause a false positive for blood on urine dipstick testing, but microscopic analysis will not be consistent with hematuria Hyperkalemia may result from both lysis of muscle cells as well as AKI Hydration is the mainstay of management Clinical Considerations Clinical recognition Rhabdomyolysis is the necrosis of muscle cells leading to introduction of intracellular contents, including myoglobin, into the blood stream The classic symptoms of rhabdomyolysis include myalgias, weakness, and red or brown urine, though this triad is not always present Rhabdomyolysis may be from traumatic or nontraumatic causes Traumatic etiologies include crush injuries, vascular occlusions, and lower extremity compartment syndrome Nontraumatic causes include extreme exertion, prolonged seizure, malignant hyperthermia, DKA, hypokalemia, hypophosphatemia, metabolic myopathies, neuroleptic malignant syndrome, and cardiac arrest It has also been associated with a variety of infections, including influenza A and B, parainfluenza, coxsackievirus, EBV, herpes simplex virus, varicella zoster, human immunodeficiency virus, pyomyositis, necrotizing fasciitis, and sepsis Prescription medications, such as statins, antipsychotics, and colchicine, and illicit drugs such as cocaine, ecstasy, and amphetamines, may cause rhabdomyolysis as well AKI during rhabdomyolysis is often multifactorial, and insults include prerenal physiology, tubular cell damage, and tubular obstruction Decreased intravascular volume and prerenal physiology develop secondary to fluid sequestration within damaged muscle and intrarenal vasoconstriction Unlike hemoglobin, myoglobin is a monomer and is freely filtered into the urine Rhabdomyolysis leads to AKI through formation of intratubular casts Tubular cell injury results from tubular obstruction with