A 22-year-old, 70-kg man sustained unrecoverable traumatic brain injury and is undergoing evaluation for donation of his heart, liver, and lungs. During transplant evaluation and preparation, he becomes progressively hypotensive, with increased urine output, and laboratory evaluation is notable for a sodium of 148 mEq/L (from initial of 139 mEq/L). Administration of which of the following medications is most appropriate to increase the chances of successful organ recovery?
A. Vasopressin infusion 0.04 U/min and desmopressin 1 µg every 6 hoursCorrect Answer: D
Patients with severe brain injury and subsequent brain death before organ donation often develop multiple endocrine abnormalities. The HPA axis is particularly susceptible to ischemic injury from elevated intracranial pressure. Up to 80% of patients with brain death develop DI from reduced antidiuretic hormone (vasopressin). Hypothyroidism and hypocortisolism are also reported, albeit at lower rates. Numerous animal and clinical studies suggest that hormone replacement promotes hemodynamic stability, improves organ function, and increases the number or organs retrieved.
Several studies show that together, thyroid hormone, vasopressin, and methylprednisolone significantly increase successful organ recovery and may be associated with better cardiac recipient survival.
If DI develops and there is significant polyuria (>3 mL/kg/h), hypernatremia (sodium >145-150) and desmopressin may be administered (1-4 µg initially) and then titrated every 6 hours to urine output and osmolality, and serum sodium. If there is associated hypotension, vasopressin infusion 0.01 to 0.04 U/min may adequately treat the hypotension as well as the treat DI. Both a vasopressin infusion and desmopressin may also be administered together if one is not sufficient.
High-dose corticosteroids (methylprednisolone 1000 mg IV) reduce the inflammatory effects of brain death on organ function and may improve graft function after transplantation.
There is some controversy regarding the benefit of thyroid hormone supplementation, as not all studies have shown benefit. It seems to have the most benefit in hemodynamically unstable donors under consideration for cardiac donation. In this patient it would be warranted given his hypotension and potential cardiac donation, with little potential for harm.
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