Management of Exercise-Induced Rhabdomyolysis
The management for this 22-year-old male with exercise-induced rhabdomyolysis should focus on aggressive hydration with intravenous fluids, monitoring renal function, and preventing complications.
Diagnosis
- The patient's presentation with muscle soreness after tennis and significantly elevated creatine kinase (CK) of 1665 U/L (>3 times upper limit of normal) confirms the diagnosis of rhabdomyolysis 1
- The elevated liver enzymes (AST 68 IU/L, ALT 52 IU/L) are likely secondary to muscle breakdown rather than primary liver injury 2, 3
- Rhabdomyolysis typically presents with an AST-dominant pattern of aminotransferase elevation, which is consistent with this patient's lab values (AST > ALT) 2
Initial Management
Immediate aggressive fluid resuscitation with crystalloid solution is the cornerstone of treatment to prevent acute kidney injury 4, 1
- Target urine output of 1-2 mL/kg/hour
- Continue until CK levels show a clear downward trend
Monitor vital signs, urine output, and electrolytes (particularly potassium, calcium, and phosphate) 1
Serial monitoring of CK levels (daily) until trending downward 1
Serial monitoring of renal function (BUN, creatinine) to assess for acute kidney injury 4
Specific Interventions
Urine alkalinization may be considered if there is evidence of acidosis or myoglobinuria (reddish urine) 4
- Add sodium bicarbonate to IV fluids to maintain urine pH > 6.5
Consider forced diuresis with adequate hydration if renal function remains stable 4
Avoid nephrotoxic medications during the acute phase 1
Monitoring and Follow-up
Continue monitoring CK levels until they decrease to <5 times the upper limit of normal 1
Monitor liver enzymes, as they should normalize with resolution of rhabdomyolysis 3
Calculate McMahon score on admission - a score ≥6 predicts higher risk of requiring renal replacement therapy 1
Activity Recommendations
Rest the affected muscles until pain resolves and CK levels normalize 5
Postpone intense physical activity when there is evidence of significant muscle damage (CK >1000 U/L) 5
Upon recovery, gradually return to physical activity with proper hydration and avoiding excessive exertion 4
Prevention of Recurrence
Implement a gradual training program when returning to sports 4
- Start with low-intensity exercise and gradually increase duration and intensity
Maintain adequate hydration before, during, and after exercise 4
Consider measuring body weight before and after long exercise sessions to guide fluid replacement (should not lose more than 2-3% of pre-exercise weight) 4
Avoid exercising in extreme environmental conditions 4
Common Pitfalls to Avoid
Do not mistake elevated liver enzymes as primary liver disease in the setting of rhabdomyolysis 2, 3
- AST is present in both liver and muscle tissue, while ALT is more liver-specific but can still be elevated in muscle injury
Avoid unnecessary liver investigations when aminotransferase elevations are proportional to CK elevation 3
Do not delay fluid resuscitation while waiting for additional test results 1
Avoid NSAIDs during the acute phase as they may worsen renal function 4
This case represents a classic presentation of exercise-induced rhabdomyolysis in a young adult, with the characteristic pattern of elevated CK and AST-dominant aminotransferase elevation. With prompt recognition and appropriate management, the prognosis is generally excellent 1, 6.