High-dose hydroxocobalamin in end-stage liver disease and liver transplantation.

Distributive shock is a serious complication in patients with chronic or end-stage liver disease, and can be exacerbated by vasoplegia in this patient population. Vasoplegic syndrome (VS) is a state of shock refractory to catecholamines and vasopressin that is often multifactorial in liver failure patients, and can occur in any phase of liver transplantation (LT) [i.e., pre-transplantation, intraoperative, and post-transplantation]. Methylene blue (MB) has been a well-established pharmacologic therapy for VS. However, it has been known to cause dose-related toxicity. Hydroxocobalamin (HXC) is not currently FDA approved for the management of VS, but studies have demonstrated its ability to cause an increase in systolic blood pressure by hypothesized mechanisms with only minimal side effects. To date, only three other reports have demonstrated the use of HXC in LT patients, which highlighted its use both intraoperatively and post-transplantation. Our report illustrates the utility of HXC in four LT patients with VS. Two of these cases illustrate the usefulness of HXC in the pre-transplantation period, which has never been previously reported. HXC is a useful pharmaceutical agent in the management of VS, especially if contraindications to MB exist or in cases of MB-resistant vasoplegia. Further studies with large sample sizes are necessary to ascertain the optimal dosage of HXC in LT patients.