Cardiorespiratory response to sedative premedication in preschool children : a randomized controlled trial comparing midazolam, clonidine, and dexmedetomidine

Purpose: Sedative premedication in children may negatively impact their cardiorespiratory status during the perioperative course, and no clear consensus exists on the optimal premedication treatment for pediatric patients. The objective was to compare the perioperative cardiorespiratory responses to sedation using three different sedative premedication regimens in preschool children scheduled for surgery with total intravenous anesthesia. Design: A single-center randomized controlled trial. Methods: This is a planned secondary analysis of a study conducted at a 200-bed tertiary referral hospital. Ninety children participated in the study. They were aged 2–6 years and scheduled for ear, nose, and throat surgery with propofol/remifentanil anesthesia. Participants were randomly assigned to receive oral midazolam 0.5 mg/kg-1 (MID), oral clonidine 4 mcg/kg–1 (CLO), or intranasal dexmedetomidine 2 mcg/kg-1 (DEX). The main outcome measures were the sedation level, based on the Ramsay Sedation Scale (RSS), and cardiorespiratory status, monitored during the perioperative period. Findings: The final cohort had 83 children (MID, n=27; CLO, n=26; DEX, n=30), with similar intergroup patient characteristics. RSS scores were lower in the MID group than in the CLO and DEX groups before induction and within 30 min postsurgery (P<0.001 and P=0.006, respectively). A negative correlation existed between the RSS and heart rate (HR) (r=-0.570, P<0.001). Before anesthesia induction, the respiratory rate was lowest in the DEX group (MID 21.5±1.7 min–1, CLO 20.6±2.6 min–1, DEX 20.2±1.7 min–1; P=0.042). The HR was lower in the CLO and DEX groups than in the MID group (MID, 102.8±10.0 min–1; CLO, 87.4±9.6 min–1; DEX, 87.6±7.9 min–1; P<0.001). The HR was lower immediately after induction (P=0.009) and intraoperatively (P=0.025) in the CLO and DEX groups than in the MID group. Conclusions: When used as premedication before propofol/remifentanil anesthesia, clonidine and dexmedetomidine