Methylene Blue Use in Pediatric Patients in the Cardiovascular Intensive Care Unit

Abstract

Objective: 1) Compare trends in mean arterial blood pressures and vasoactive-inotropic scores of pediatric patients after treatment of hypotension with methylene blue compared to controls; 2) Describe the dose administered and the pathologies of hypotension cited for methylene blue use; 3) Compare the morbidity and mortality of pediatric patients treated with methylene blue versus controls. Design: A retrospective chart review. Setting: Cardiac ICU in a quaternary care free-standing children’s hospital. Patients: Thirty-two patients with congenital heart disease who received methylene blue as treatment for hypotension, fifty patients with congenital heart disease identified as controls. Interventions: None. Measurements and Main Results: Demographic and vital sign data was collected for all pediatric patients treated with methylene blue during a three year period. Linear regression models examined trends in mean arterial blood pressures twelve hours post methylene blue treatment and vasoactive-inotropic scores for twenty-four hours post treatment. Methylene blue treatment correlated with an increase in mean arterial blood pressure of 10.8mm Hg over a twelve hour period (p< 0.001). Mean arterial blood pressure trends of patients older than one year did not differ significantly from controls (p=0.79), but patients less than or equal to one year of age had increasing mean arterial blood pressures that trended toward significance compared to controls (p=0.07). Similarly, a statistically significant decrease in vasoactive-inotropic scores was observed over a twenty-four hour period (?= -0.62, p< 0.001, ECMO ?= -6.07, p= 0.029). This difference remained significant compared to controls (p=0.001). Survival estimates did not detect survival differences between the groups (p=0.5). Conclusion: Methylene blue may be associated with a decreased need for vasoactive-inotropic support and may correlate with an increase in mean arterial blood pressure in patients who are less than or equal to one year of age.