Methylene blue (MB) is a medication commonly used to treat
methemoglobinemia, reducing
methemoglobin to
hemoglobin. A novel use of MB, as detailed here, is in the treatment of refractory
hypotension. A number of reports have detailed use of MB for this purpose in adults, but few data in pediatrics. A 22-month-old girl with
Noonan syndrome, biventricular
hypertrophic cardiomyopathy, and chronic
positive pressure ventilation developed
shock with
tachycardia,
hypotension, and
fever after 3 days of
diarrhea. She was
critically ill, with warm extremities, bounding pulses, and brisk capillary refill. Laboratory tests revealed
metabolic acidosis, low mixed venous oxygen saturation, and
leukocytosis with bandemia. Treatment of severe
septic shock was initiated with fluid
resuscitation, inotropic support, sedation, and
paralysis. She remained hypotensive despite
norepinephrine at 0.7 μg/kg per minute,
dopamine at 20 μg/kg per minute, and
vasopressin at 0.04 U/kg per hour. Her vasoplegic
shock worsened, despite aggressive conventional
therapy. Intravenous MB was initiated, with a loading dose of 1 mg/kg followed by a continuous infusion at 0.25 mg/kg per hour. Upon initiation of MB, her systolic blood pressure increased by 33 points (40% increase), and diastolic blood pressure increased by 20 points (46% increase). She was able to wean off all inotropes quickly after initiation of MB. MB should be considered in the setting of refractory vasoplegic
shock in the PICU.