Intranasal dexmedetomidine: the ideal drug for sedation in the pediatric echo lab?

BACKGROUND: Intranasal dexmedetomidine is an attractive option for procedural sedation in pediatrics due to ease of administration and its relatively short half-life. This study sought to compare the safety and efficacy of intranasal dexmedetomidine to a historical cohort of pediatric patients sedated using chloral hydrate in a pediatric echo lab. METHODS: Chart review was performed to compare patients sedated between September, 2017 and October, 2019 using chloral hydrate and intranasal dexmedetomidine. Vital signs, time to sedation, duration of sedation, need for second dose of medication, rate of failed sedation, and impact on vital signs were compared between groups. Subgroup analysis was performed for those with complex and cyanotic heart disease. RESULTS: Chloral hydrate was used in 356 patients and intranasal dexmedetomidine in 376. Patient age, complexity of heart disease, and duration of sedation were similar. Rates of failed sedation were very low and similar. Average heart rate and minimum heart rate were lower for those receiving intranasal dexmedetomidine than chloral hydrate. Impact on vital signs was similar for those with complex and cyanotic heart disease. No adverse events occurred in either group. CONCLUSIONS: Sedation with intranasal dexmedetomidine is comparable to chloral hydrate in regards to safety and efficacy for children requiring echocardiography. Consistent with the mechanism of action, patients receiving intranasal dexmedetomidine have a lower heart rate without morbidity.

Increases in oxygen saturation following discharge from Fontan palliation - an indicator of resolution of pulmonary arteriovenous malformations?

BACKGROUND: Pulmonary arteriovenous malformations in single ventricle congenital heart disease are poorly understood. Previous studies investigating pulmonary arteriovenous malformations predominantly focus on patients with heterotaxy syndrome and interrupted inferior caval vein. It is unknown if development and resolution of pulmonary arteriovenous malformations are similar for patients with and without heterotaxy syndrome. METHODS: In this retrospective single-institution study, we identified patients with a history of single ventricle congenital heart disease and Fontan palliation. We then matched patients with heterotaxy syndrome (intact and interrupted inferior caval vein) and non-heterotaxy hypoplastic left heart syndrome. To compare development of pulmonary arteriovenous malformations, we identified the frequency of positive diagnoses pre-Fontan. To compare resolution of pulmonary arteriovenous malformations, we recorded oxygen saturation changes for 12 months following Fontan. RESULTS: A total of 124 patients were included. Patients with heterotaxy and interrupted inferior caval vein were more likely to have a pre-Fontan contrast echocardiogram performed (p < 0.01) and more likely to be diagnosed with pulmonary arteriovenous malformations pre-Fontan (p < 0.01). There was no difference in oxygen saturation prior to Fontan, yet all patient groups had increased their oxygen saturations in the first year after Fontan discharge. CONCLUSIONS: Pulmonary arteriovenous malformations are variably diagnosed prior to Fontan palliation; however, all study groups had increased oxygen saturations after Fontan discharge, potentially indicating resolution of pulmonary arteriovenous malformations in all groups. The prevalence of pulmonary arteriovenous malformations pre-Fontan is likely underestimated. A quantitative, systematic approach to diagnosis and follow-up of pulmonary arteriovenous malformations is needed to better understand susceptibility and pathophysiology.

Echocardiographic Identification of Pulmonary Artery Flow Reversal: An Indicator of Adverse Outcomes in Single Ventricle Physiology.

Individuals with single ventricle congenital heart disease (CHD) undergo multiple staged surgical palliations. Staged single ventricle palliation with a superior cavopulmonary connection (SCPC) in infancy followed by a Fontan in early childhood relies on passive, unobstructed pulmonary blood flow and normal pulmonary vasculature. We hypothesized that patients with echocardiographic identification of retrograde flow in a branch pulmonary artery (PA) after SCPC or Fontan are at increased risk for adverse outcomes. We conducted a retrospective chart review of patients seen at Children's Wisconsin from 1999 to 2019. Inclusion criteria included a history of single ventricle congenital heart disease and surgical palliation with a superior cavopulmonary connection (SCPC). We created two cohorts based on transthoracic echocardiographic identification of branch PA flow patterns: those with color Doppler-defined pulmonary artery flow reversal (PA reversal cohort) and those with normal anterograde flow (Non-reversal cohort). We identified 21 patients in the PA reversal cohort and 539 patients in the Non-reversal cohort. The PA reversal cohort had increased hospital length of stay after SCPC palliation (p < 0.001) and decreased transplant-free survival (p = 0.032), but there was no difference in overall survival (p = 0.099). There was no difference in hospital length of stay after Fontan (p = 0.17); however, the PA reversal cohort was significantly less likely to progress to Fontan palliation during early childhood (p = 0.005). Echocardiographic color Doppler identification of branch PA flow reversal in patients with single ventricle physiology is a high-risk indicator for adverse short- and long-term outcomes.