The role of methylene blue in the pediatric patient with vasoplegic syndrome.

Patients with vasoplegic syndrome (VPS) in the post-cardiopulmonary bypass setting usually require escalating vasopressor support. The utilization of methylene blue (MB) in the treatment of VPS in the adult population has been well described. We present a 5-year-old girl who developed vasodilatory shock due to VPS that was resistant to escalating doses of adrenergic agonists following cardiac transplantation. After receiving 1 mg/kg of MB, there was a significant improvement in the patient's mean arterial pressure which allowed for progressive weaning of the vasopressor support. To date, there are limited data regarding the use of MB in pediatric patients with VPS following cardiothoracic surgery. The cellular mechanisms of MB in VPS are discussed and reports of its use in the adult and pediatric population are reviewed. Dosing regimens and potential adverse effects of MB are presented.