Effectiveness of Dexmedetomidine as Myocardial Protector in Children With Classic Tetralogy of Fallot Having Corrective Surgery: A Randomized Controlled Trial.

OBJECTIVES: Efficacy of dexmedetomidine (DEX) as a cardioprotective agent in Indonesian children undergoing classic tetralogy of Fallot (TOF) repair with cardiopulmonary bypass (CPB). DESIGN: A prospective, parallel trial using block randomization along with double-blinded preparation of treatment agents by other parties. SETTING: National Cardiovascular Center Harapan Kita, Indonesia. PARTICIPANTS: Sixty-six children with classic TOF scheduled for corrective surgery. No children were excluded. All patients had fulfilled the criteria for analysis. INTERVENTIONS: A total of 0.5 µg/kg bolus of DEX was added to the CPB priming solution, followed by 0.25 µg/kg/h maintenance during bypass. The placebo group used normal saline. Follow-ups were up to 30 days. MEASUREMENTS AND MAIN RESULTS: Troponin I was lower in the DEX group at 6 hours (30.48 ± 19.33 v 42.73 ± 27.16, p = 0.039) and 24 hours after CPB (8.89 ± 5.42 v 14.04 ± 11.17, p = 0.02). Within a similar timeframe, DEX successfully lowered interleukin-6 (p = 0.03; p = 0.035, respectively). Lactate was lower in the Dex group at 1, 6, and 24 hours after CPB (p < 0.01; p = 0.048; p = 0.035; respectively). Dexmedetomidine increased cardiac output and index from 6 hours after bypass, but vice versa in systemic vascular resistance. Reduction of vasoactive inotropic score was seen during intensive care unit monitoring in the Dex group (p = 0.049). Nevertheless, DEX did not significantly affect the length of ventilation (p = 0.313), intensive care unit stay (p = 0.087), and mortality (p > 0.99). CONCLUSIONS: Dexmedetomidine during CPB is an effective cardioprotective agent in TOF children having surgery. Postoperative mortality was comparable across groups.

Risk Factors Associated With Prolonged Mechanical Ventilation and Length of Stay After Repair of Tetralogy of Fallot.

BACKGROUND: This study examined preoperative, intraoperative, and postoperative data to identify factors that are associated with prolonged mechanical ventilation (PMV) and prolonged intensive care unit length of stay (ICU LOS) in tetralogy of Fallot (TOF) patients undergoing repair surgery. METHODS: A retrospective study was carried out after approval from the institutional review board. All patients (age 0-52 years) who underwent TOF repair from January 2016 to September 2022 were included. Prolonged mechanical ventilation was defined as >24 h of ventilation, while prolonged ICU LOS was defined as ICU stay >3 days. RESULTS: A total of 922 patients were included, among whom 288 (31.2%) were intubated for >24 h and 222 (24.1%) stayed in ICU for >3 days. Younger age (odds ratio [OR] = 2, 95% confidence interval [CI] 1.2-3.3, P = .007), lower weight (OR = 2.1, 95% CI 1.2-3.5, P = .003), and residual lesion (OR = 3.27, 95% CI 1.2-8.7, P = .017) were associated with PMV. Moreover, independent risk factors for prolonged ICU LOS are similar to PMV risk factors, including younger age (OR = 2.3, 95% CI 1.28-4.12, P = .005), lower weight (OR = 2.83, 95% CI 1.58-5, P < .001), underweight status (OR = 1.7, 95% CI 1.12-2.57, P = .012), and residual lesion (OR = 3.79, 95% CI 1.43-10.05, P = .007). Both aortic cross-clamp and cardiopulmonary bypass times did not exhibit clinically significant risk factors toward PMV and prolonged ICU LOS. CONCLUSIONS: The risk factors for PMV and prolonged ICU LOS were residual lesion, younger age, and lower weight. Nutritional status contributed to the risk of prolonged ICU LOS, but not PMV. Consideration of these factors may provide optimal care to improve the outcome following TOF corrective surgery.

Dexmedetomidine as a myocardial protector in pediatric heart surgery using cardiopulmonary bypass: a systematic review.

Background: In recent years, dexmedetomidine has been studied as a cardioprotective agent. However, studies on its application in pediatric heart surgery using cardiopulmonary bypass (CPB) remain limited. This systematic review aimed to provide information on the cardioprotective effect of dexmedetomidine in children undergoing heart surgery using CPB. Methods: The authors searched several databases (MEDLINE, Embase, Cochrane Library, etc.) to identify all trials comparing the levels of myocardial injury via biomarkers, including pediatric patients undergoing heart surgery using CPB who received dexmedetomidine versus placebo or other anesthetic agents. Literatures from non-primary studies were excluded. Two reviewers independently screened studies for eligibility and extracted data. The Cochrane Risk-of-Bias tool was implemented to evaluate any potential biases. Information from eligible studies was summarized and correspondingly reviewed based on any quantitative outcomes. Results: We identified six trials composed of 419 participants, three of which (n=241) showed significantly reduced interleukin-6 (IL-6) levels in the dexmedetomidine group, while one study (n=40) showed no IL-6 difference between groups. Cardiac troponin I (cTnI) and creatinine kinase-myocardial band (CK-MB), as myocardial injury biomarkers, were found to be lower in two trials (n=180). Despite several limitations hindering this review from pooling the data objectively, the majority of published studies indicated that dexmedetomidine is a seemingly efficacious agent protecting against cardiac injury during bypass. Conclusions: These studies suggest that dexmedetomidine has cardioprotective effects through the lowering of cardiac injury biomarkers while improving its clinical outcomes after heart surgery using bypass.