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).