Hypernatremia in brain-dead patients.

Objectives: Hypernatremia often occurs in patients with brain death. This study summarizes its characteristics.

Methods: We recorded 57 patient's highest blood sodium value, as well as daily NT-proBNP, blood creatinine, and urine output. Further, we analyzed the time of the first rise in blood sodium, and the relationship between NT-proBNP, serum creatinine, urine output, and serum sodium.

Results: There was no hyponatremia in these patients, and only seven of the 53 patients registered blood sodium between 137 and 150 mmol/L. We found that blood sodium started to rise at 36.0 (28.5-52.3) h, reaching the highest value in 79.0 (54.0-126.0) h. Urine volume and creatinine have no correlation with serum sodium level, while NT-proBNP has a significant correlation with serum sodium level.

Conclusion: It is necessary to conduct volume assessments and urine electrolyte testing on patients with brain death. BNP has a protective effect on water and electrolytes to prevent hypernatremia.