What is the initial treatment for hospital inpatients with rhabdomyolysis, specifically for Physical Medicine and Rehabilitation (PM&R) treatment?

Initial Treatment of Rhabdomyolysis in Hospital Inpatients for PM&R

Aggressive intravenous fluid resuscitation with isotonic saline is the cornerstone of initial treatment for hospital inpatients with rhabdomyolysis, targeting a urine output of >300 mL/hour to prevent acute kidney injury. 1, 2, 3

Diagnosis Confirmation and Initial Assessment

• Monitor serum creatine kinase (CK) levels every 6-12 hours in the acute phase, with rhabdomyolysis typically diagnosed when CK is at least 10 times the upper limit of normal 1
• Check for myoglobinuria (tea/cola-colored urine) that tests positive for blood on dipstick but negative for RBCs on microscopy 1
• Assess for the classic triad of myalgia, muscle weakness, and pigmenturia, though this is present in less than 10% of cases 1
• Perform baseline kidney function tests, electrolyte panel, and urinalysis 1

Immediate Treatment Protocol

Fluid Resuscitation

• Begin aggressive hydration with isotonic saline (0.9% NaCl) as the initial fluid of choice 1, 4
• Target urine output >300 mL/hour to prevent acute kidney injury 1, 3
• Avoid potassium-containing fluids such as Lactated Ringer's 1
• Continue IV fluids until CK levels decrease to <1,000 U/L 3

Electrolyte Management

• Monitor and correct hyperkalemia urgently if present 1
• Address hypocalcemia if symptomatic 1
• Check serum electrolytes, urea nitrogen, and creatinine during treatment 5

Additional Interventions

• Discontinue any causative agents (e.g., statins) 1
• Avoid all nephrotoxic medications, including NSAIDs, ACE inhibitors/ARBs, and certain antibiotics 1
• Monitor for and treat compartment syndrome if present, with urgent surgical consultation for fasciotomy if confirmed 1

Evidence-Based Considerations

• Current evidence does not strongly support routine use of bicarbonate-containing fluids or mannitol 2, 6, 4
• A systematic review by the Eastern Association for the Surgery of Trauma conditionally recommends against treatment with bicarbonate or mannitol in patients with rhabdomyolysis 2
• Early and aggressive fluid resuscitation is the main intervention with consistent evidence for preventing and treating AKI 6

Monitoring and Follow-up

• Monitor CK levels until they decrease to <1,000 U/L 3
• Assess kidney function regularly to detect acute kidney injury early 1
• Consider nephrology consultation for all cases with acute kidney injury 1
• Consider renal replacement therapy for severe hyperkalemia, acidosis, volume overload, or uremic symptoms 1

Complications to Monitor

• Acute kidney injury (occurs in up to 57% of untreated cases) 1
• Electrolyte abnormalities, particularly hyperkalemia 1
• Compartment syndrome (monitor for pain, tension, paresthesia, and paresis in affected limbs) 1
• Cardiac arrhythmias due to electrolyte disturbances 1

PM&R-Specific Considerations

• Begin early mobilization once the patient is medically stable
• Implement gradual return to activity based on CK levels and clinical symptoms
• Provide education on proper hydration and exercise techniques to prevent recurrence
• Develop a rehabilitation plan that addresses any residual muscle weakness or functional limitations

By following this evidence-based approach focusing on aggressive fluid resuscitation and careful monitoring, PM&R specialists can effectively manage rhabdomyolysis in hospital inpatients while preventing serious complications like acute kidney injury.