Preincision Initiation of Dexmedetomidine Maximally Reduces the Risk of Junctional Ectopic Tachycardia in Children Undergoing Ventricular Septal Defect Repairs.

OBJECTIVE: To evaluate whether initiation of dexmedetomidine (DEX) infusion before surgical incision and cardiopulmonary bypass (CPB) versus initiation after CPB had an impact on the incidence of junctional ectopic tachycardia (JET). DESIGN: Retrospective cohort study. SETTING: Single tertiary-care cardiac center. PARTICIPANTS: Children undergoing cardiopulmonary bypass for repair of congenital heart disease involving ventricular septal defects between January 2010 and February 2013. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred thirty-four patients undergoing ventricular septal defect closure were included in the final analysis. Of the 99 patients (74%) exposed to DEX, intraoperative initiation was performed in 73 (pre-CPB, n = 39 patients [29%]; intraoperative post-CPB initiation, n = 34 patients [25%]), and postoperative initiation was performed on arrival to the intensive care unit (ICU) in 26 patients (19%). In 71 of the 73 patients, infusions that were initiated intraoperatively were continued in the postoperative period for up to the first 12 hours. Postoperative JET was observed in 22 of the 134 patients (15%). Of the 99 patients exposed to DEX in the perioperative period, JET was observed in 8 patients (11%). Of the 35 patients not exposed to any DEX, JET was observed in 12 patients (34%). Analysis was performed using DEX exposure and timing as predictor variables. Multivariable analysis modeled with DEX exposure as a predictor variable showed that when initiated preincision and continued through the postoperative period, DEX was associated with significant reduction in postoperative JET (odds ratio [OR] 0.09, 95% confidence interval [CI] 0.02-0.37, p = 0.002). Exposure to DEX in the postoperative period alone did not result in suppression of JET (OR 0.5, 95% CI 0.11-2.17, p = 0.366). When modeled by using timing of DEX initiation as the predictive variable, preincision initiation of DEX infusion resulted in significantly greater suppression of JET (OR 0.04, 95% CI 0.002-0.28, p = 0.006) compared with initiation intraoperatively after CPB (OR 0.16, 95% CI 0.03-0.71, p = 0.024) or on arrival to the ICU (OR 0.504, CI 0.105-2.171, p = 0.365). Use of DEX exclusively in the postoperative period did not demonstrate any significant benefit in reducing JET (OR 0.506, 95% CI 0.106-2.17, p = 0.366). CONCLUSIONS: Preincision initiation of DEX and its continued use during the immediate postoperative period are significantly associated with reduced risk of JET after congenital heart surgeries involving repair of ventricular septal defect.

Anomalous Origin of Coronary Artery From Main Pulmonary Artery in Hypoplastic Left Heart Syndrome.

We report a case of anomalous origin of the left anterior descending coronary artery (LAD) from the main pulmonary artery in a child with hypoplastic left heart syndrome (mitral atresia/aortic atresia). Mechanical circulatory support was necessary because of the inability to wean from cardiopulmonary bypass after the Norwood procedure. The patient died at 4 months of age having continued depressed right ventricular function. The diagnosis was made during a catheterization performed 6 weeks after surgery because of concern for stenosis of Blalock-Taussig shunt. We believe his prolonged postoperative recovery and eventual demise can partially be attributed to lack of cardioplegia to the anomalous LAD territory during surgery.

Characterizing the Risk Factors Associated With Venous Thromboembolism in Pediatric Patients After Central Venous Line Placement.

OBJECTIVES: With the apparent increase in venous thromboembolism noted in the pediatric population, it is important to define which children are at risk for clots and to determine optimal preventative therapy. The purpose of this study was to determine the risk factors for venous thromboembolism in pediatric patients with central venous line placement. METHODS: This was an observational, retrospective, case-control study. Control subjects were patients aged 0 to 18 years who had a central venous line placed. Case subjects had a central line and a radiographically confirmed diagnosis of venous thromboembolism. RESULTS: A total of 150 patients were included in the study. Presence of multiple comorbidities, particularly the presence of a congenital heart defect (34.7% case vs. 14.7% control; p < 0.005), was found to put pediatric patients at increased risk for thrombosis. Additionally, the administration of parenteral nutrition through the central line (34.7% case vs. 18.7% control; p = 0.03) and location of the line increased the risk for clot formation. CONCLUSIONS: With increased awareness of central venous line-related thromboembolism, measures should be taken to reduce the number and duration of central line placements, and further studies addressing the need for thromboprophylaxis should be conducted.