INVESTIGATIONS
Initial labs (Table 1) were suggestive of mild normocytic anemia with hemoglobin of 12.7 g/dL (baseline 12-13), AKI on CKD (Creatinine = 3.52 mg/dL, baseline of 1.6-1.8), elevated serum CK (> 22,000 IU/L), and BNP > 3000 pg/mL. Liver function tests showed markedly elevated transaminases and hypoalbuminemia. In addition, he had an elevated ESR. Thyroid function testing revealed an elevated TSH with normal T3 and T4. Urinalysis showed cloudy-orange appearing urine with dipstick “large” positive for blood, but only 2 RBCs per high power field (HPF), a disparity highly suggestive of myoglobinuria versus hemoglobinuria. The former was more likely given elevated CK and transaminases, raising suspicion for rhabdomyolysis. Overall his labs were significant for rhabdomyolysis and AKI on CKD. However, serum electrolytes and arterial blood gas analysis were normal.
The patient also underwent further workup of etiology for rhabdomyolysis. Urine drug screen was negative. EEG was normal and seizures were ruled out based on history. On routine respiratory pathogen panel testing for infectious etiology, he was found to be COVID-19 PCR positive on a nasopharyngeal swab. However serial chest X-rays (Fig 1) were negative for pneumonia. Given the absence of fever, cough or chest x-ray findings, and normal oxygen requirements, this was an asymptomatic COVID-19 infection. Given the pedal edema, a lower extremity duplex scan was performed and was negative for deep vein thrombosis. In addition, transthoracic echocardiography showed normal cardiac function, and ECG showed a normal sinus rhythm. Further cardiac evaluation was deferred since the elevated BNP was presumed to be due to impaired excretion in the setting of renal dysfunction. Liver ultrasound showed normal echogenicity. Renal ultrasound showed increased echogenicity of the right kidney, with normal echogenicity of the left kidney. Therapeutic drug testing of blood showed elevated levels of levetiracetam (93 mcg/mL; range: 10- 40), sub-therapeutic levels of valproate (29.1 mcg/mL, range 50-100), and sub-therapeutic levels of cyclosporine (35.7 ng/mL; range 100-400).