What are the diagnosis and management strategies for rhabdomyolysis?

From the Guidelines

Rhabdomyolysis should be diagnosed and managed promptly with aggressive intravenous fluid resuscitation, monitoring of electrolytes, and identification of the underlying cause to reduce morbidity and mortality. The diagnosis of rhabdomyolysis is based on a combination of clinical presentation, elevated creatine kinase (CK) levels typically above 1,000 U/L, and the presence of myoglobinuria 1. Management focuses primarily on aggressive intravenous fluid resuscitation with normal saline at 200-300 mL/hour initially, aiming to maintain urine output at 200-300 mL/hour until CK levels decrease significantly 1. Key aspects of management include:

• Fluid therapy should be continued until CK levels fall below 1,000 U/L or decrease by 50% from peak values
• Monitoring of electrolytes, particularly potassium, calcium, and phosphorus, with correction as needed
• Hyperkalemia may require treatment with calcium gluconate, insulin with glucose, or sodium bicarbonate in severe cases
• Urinary alkalinization with sodium bicarbonate may be considered if the patient develops acidosis or myoglobinuria, though this remains controversial 1
• Renal function should be closely monitored, and if acute kidney injury develops, nephrology consultation for possible renal replacement therapy is warranted
• The underlying cause of rhabdomyolysis must be identified and addressed, whether it's trauma, excessive exercise, medications, infections, or metabolic disorders 1. Patients should be advised to maintain adequate hydration after discharge and avoid precipitating factors to prevent recurrence.

From the Research

Diagnosis of Rhabdomyolysis

• Rhabdomyolysis is a potentially life-threatening condition caused by a breakdown of skeletal muscle and the release of the intracellular contents into the circulatory system 2
• The diagnosis of rhabdomyolysis should be considered when patients present with circumstances known to be high-risk for rhabdomyolysis, including intoxication, prolonged immobilization, and/or altered mentation 2
• Serum potassium levels must be obtained and electrocardiograms must be evaluated to identify life- and limb-threatening complications of hyperkalemia 2
• Creatine kinase (CK) level is a biological marker for the identification of patients at high risk of acute kidney injury (AKI) following rhabdomyolysis, with a PEAK CK of at least 5000 Ul being 55% specific and 83% sensitive for the prediction of AKI requiring renal replacement therapy (RRT) 3

Management of Rhabdomyolysis

• Aggressive intravenous fluid resuscitation (IVFR) is indicated to prevent myoglobinuric renal failure, with a goal of ≥12 l daily intravenous infusion of alkaline solution started at the scene of injury 4
• IVFR has been shown to decrease the incidence of acute renal failure (ARF) and need for dialysis in patients with rhabdomyolysis 5
• The use of bicarbonate and mannitol in the treatment of rhabdomyolysis is not recommended, as they have not been shown to improve outcomes and may even be harmful 5, 6
• High-volume fluid resuscitation (≥3 mL/kg/hr) has been associated with worse renal outcomes and higher mortality compared to low-volume fluid resuscitation (<3 mL/kg/hr) 6
• The McMahon Score has been validated as a prognostic marker for AKI and RRT in patients with rhabdomyolysis, with a score of at least 6 being 68% specific and 86% sensitive for RRT 3