Chapter 11: Rhabdomyolysis
A 22-year-old woman presents to the emergency department with severe upper arm pain, red urine, and generalized weakness. She recently underwent a high-intensity-resistance training workout 48 hours prior to presentation. She has no history of prescription or other drug use.
Evaluation reveals blood pressure 130/70 mm Hg and pulse 110 beats/min. Physical examination is positive for tenderness to palpation over proximal arms bilaterally.
|CBC ||Normal |
|Creatinine ||1.5 mg/dL |
|Sodium ||135 mEq/L |
|Potassium ||5.2 mEq/L |
|Chloride ||110 mEq/L |
|Bicarbonate ||21 mEq/L |
|Phosphorous ||5.4 mEq/L |
|Urinalysis ||3+ blood, negative protein, 0 red blood cell count per high-power field (RBC/hpf) |
What is the most likely diagnosis?
D. Acute glomerulonephritis
The answer is B. The history of exertional trauma, myoglobinuria (positive dipstick for blood, negative microscopy) and acute kidney injury most likely points to rhabdomyolysis. Polymyositis is excluded based on acute presentation following exercise. IgA nephropathy and other acute glomerulonephritis are unlikely diagnoses given negative urine microscopy.
A 68-year-old man with a history of diabetes, hypertension, and coronary artery disease presents for evaluation of generalized fatigue and myalgias. One month ago he was hospitalized for angina, during which high-dose atorvastatin was added on discharge. Other medications include aspirin, metoprolol, amlodipine, lisinopril, and insulin. The patient reports compliance with all medications.
Examination reveals blood pressure 140/70 mm Hg and heart rate 65 beats/min. Physical examination is positive for generalized muscle tenderness.
What is the next best step in this patient’s management?
A. Discontinuation of atorvastatin
B. Normal saline infusion at 500 mL/h
C. Cardiology evaluation for possible acute coronary syndrome (ACS)
D. Sodium bicarbonate infusion
The answer is A. This patient most likely has statin induced rhabdomyolysis, given recent addition of atorvastatin to medication regimen. Discontinuation of offending medication would be most appropriate at this time. Normal saline infusion is not applicable in this situation, given mild CK elevation, and low risk for developing acute kidney injury. Similarly, sodium bicarbonate infusion is not indicated at this time. Cardiology evaluation is not indicated, given the rise in CK levels after ...