Which of the following is incorrect about rhadomyolysis-induced kidney injury?
A. Myoglobin seems to have no marked nephrotoxic effect in the tubules unless the urine is acidic
B. Conventional hemodialysis does not remove myoglobin effectively owing to the size of the protein and is therefore usually mandated by renal indications. CVVH or CVVHDF has shown some efficacy in removing myoglobin, principally with the use of super high-flux filters and high volumes of ultrafiltration (convection)
C. Hypercalcemia can be seen in the latter phase associated with recovery of renal function.
D. Hypocalcemia in the initial phase requires aggressive treatment
Answer: D
Myoglobin becomes concentrated along the renal tubules, a process that is enhanced by volume depletion and renal vasoconstriction, and it precipitates when it interacts with the Tamm–Horsfall protein, a process favored by acidic urine.
Hypocalcemia usually results from calcium entering the ischemic and damaged muscle cells and from the precipitation of calcium phosphate with calcification in necrotic muscle. Hypercalcemia associated with recovery of renal function is unique to rhabdomyolysis-induced acute kidney injury and results from the mobilization of calcium that was previously deposited in muscle, the normalization of hyperphosphatemia, and an increase in calcitriol.
Administration of bicarbonate infusion for alkalinization may reduce ionized calcium, which can exacerbate the symptoms of the initial hypocalcemic phase of rhabdomyolysis. Early hypocalcemia should not be treated unless it is symptomatic or unless severe hyperkalemia is present.
Reference
2009 NEJM: Review Article: Rhabdomyolysis and Acute Kidney Injury