Effect of premedication with clonidine, midazolam, and dexmedetomidine on stress response and sedation in pediatric congenital cardiac surgeries

Abstract

Background Children undergoing cardiac surgery experience a substantial stress response mediated by the release of stress hormones and cytokines. Providing sedation and blunting stress response by one drug in a single oral dose and excellent oral bioavailability of clonidine prompted us to study its efficacy as premedication in pediatric patients and compare it with both oral midazolam, a gold standard premedication in pediatric patient, and oral dexmedetomidine, as a newer α2 receptor agonist. Aim To compare the effect of premedication with three drugs (clonidine, midazolam and dexmedetomidine) in pediatric congenital cardiac surgeries including their effect on the stress response during surgery. Patients and methods Patients were categorized into three groups (30 patients each): group clonidine (C) received oral clonidine at a dose of 4 µg/kg, group midazolam (M) received oral midazolam at a dose of 0.5 mg/kg, whereas group dexmedetomidine (Dx) received oral dexmedetomidine at a dose of 1 μg/kg. All the drugs were mixed with equal volume of 5% dextrose. Results The bispectral index measurements in group Dx became significantly lower at 15 min and 30 min compared with the other two groups. Then, significantly lower bispectral index measurements were observed in group C compared with groups M and Dx at 45 min and afterward. The serum cortisol and catecholamines levels in group C became significantly lower than that in groups M and Dx after intravenous cannulation, after sternotomy, and at the end of surgery. Conclusion Clonidine, as a preanesthetic drug in congenital heart surgery, is effective in decreasing stress response and achieving adequate level of sedation till the end of surgery. Oral dexmedetomidine has faster onset compared with midazolam in reaching the adequate level of sedation.