NEPHROGENIC DIABETES INSIPIDUS AND RHABDOMYOLYSIS WITH SEVERE HYPERNATREMIA REQUIRING HEMODIALYSIS TREATMENT

Abstract

INTRODUCTION
Severe hypokalaemia may present with respiratory muscle paralyisis and respiratory failure. In rare instances, it results in rhabdomyolysis and nephrogenic diabetes insipidus (NDI). The management of NDI with severe hypernatraemia, metabolic acidosis and renal impairment is challenging and potentially complicated.

RESULTS
A 21-year-old male presented with acute shortness of breath, fever, cough and generalised body weakness. He had severe hypokalemia (potassium level of 2.0 mmol/L) and compensated metabolic acidosis. He rapidly deteriorated requiring ventilatory support and ICU admission. His hypokalaemia was resistant to correction and he required repeated bolus potassium chloride correction. His increasing serum sodium trend subsequent polyuria (urine output between 150 to 200 mL/hour prompted the suspicion of DI. Urine output was reduced only after high dose intravenous desmopressin 4 µg. Simultaneously, he required regular potassium supplementation via intravenous and nasogastric route. Peculiarly, the patient had dark-coloured urine, which increased in intensity after desmopressin. Elevated creatinine kinase and myoglobinuria indicated rhabdomyolysis. Serum sodium trend continued to increase to a peak of 179 mmol/L. Coupled with metabolic acidosis, haemodialysis was opted as a method to reduce the sodium level. Following haemodialysis, sodium level gradually decreased with normalisation of urine output and potassium level. He made a remarkable recovery and was discharged well. Three weeks after discharge, he was readmitted for symptomatic hypokalemia with normal anion gap metabolic acidosis. The final diagnosis of renal tubular acidosis (RTA) was ascertained.

CONCLUSION
Undiagnosed RTA resulted in severe hypokalemia that led to life threatening respiratory depression, rhabdomyolysis and NDI. Haemodialysis in specific situations can be used as treatment for severe hypernatraemia.