Extrapontine myelinolysis caused by rapid correction of pituitrin-induced severe hyponatremia: A case report.

Background: Severe hyponatremia is considered a rare complication of pituitrin, which is widely used for the treatment of pulmonary hemorrhage. However, the management of pituitrin-associated hyponatremia can be challenging because a rapid correction of hyponatremia may cause the development of osmotic demyelination syndrome, resulting in life-threatening neurological injuries.

Case Summary: A 20-year-old Chinese man with massive hemoptysis developed symptomatic hyponatremia (116 mmol/L) after therapy by a continuous intravenous drip of pituitrin. To normalize his serum sodium, a hypertonic saline infusion was applied for 3 d, and the pituitrin administration was stopped concurrently. Then, an overly rapid increase in serum sodium level (18 mmol/L in 24 h) was detected after treatment. One day later, the patient experienced a sudden onset of generalized tonic-clonic seizures, as well as subsequent dysarthria and dystonia. Magnetic resonance imaging revealed increased signal intensity in the bilateral symmetric basal ganglia on the T2-weighted images, compatible with a diagnosis of extrapontine myelinolysis. The patient received an intravenous administration of high-dose corticosteroids, rehabilitation, and neurotrophic therapy. Finally, his clinical abnormalities were vastly improved, and he was discharged with few residual symptoms.

Conclusion: Physicians should be fully aware that pituitrin can cause profound hyponatremia and its correction must be performed at a controlled rate to prevent the development of osmotic demyelination syndrome.