Effects of dexmedetomidine sedation for magnetic resonance imaging in children: a systematic review and meta-analysis

Purpose Pediatric sedation is commonly required to obtain high-quality images in magnetic resonance imaging (MRI). We performed a systematic review and meta-analysis to assess the effects of dexmedetomidine sedation for MRI in children. Methods A systematic review was conducted to find all randomized controlled trials concerning dexmedetomidine sedation for MRI in children. We searched databases using the Ovid platform in the Cochrane Controlled Trials Register, MEDLINE, and EMBASE. This study was registered in the PROSPERO database: CRD42020198368. Results Seven studies and 753 participants were included. Dexmedetomidine sedation showed a significantly delayed onset time [weighted mean differences (WMD) = 8.13 min, 95% confidence interval (CI) 4.64 to 11.63, I-2 = 98%] and recovery time (WMD = 5.22 min, 95% CI 0.35 to 10.09, I-2 = 92%) compared to propofol, ketamine, and midazolam sedation. There was no difference in quality of sedation [risk ratio (RR) = 1.25, 95% CI 0.92 to 1.69, I-2 = 89%], or incidence of sedation failure (RR = 1.39, 95% CI 0.53 to 3.66, I-2 = 83%) between groups. Although a significantly decreased heart rate (WMD = - 17.34 beats/minute, 95% CI - 22.42 to - 12.26, I-2 = 96%) was observed, bradycardia that required treatment was not increased (RR = 8.00, 95% CI 1.02 to 62.64, I-2 = 0%). Dexmedetomidine sedation had a lower incidence of desaturation events (RR = 0.42, 95% CI 0.20 to 0.86, I-2 = 4%). However, there was no difference in incidence of postoperative vomiting (RR = 0.42, 95% CI 0.15 to 1.17, I-2 = 17%) between groups. Conclusions Dexmedetomidine sedation provided a similar sedation quality with a reduced incidence of desaturation events. However, the delayed onset and recovery times were drawbacks. The clinical significance of bradycardia is considered to be low. GRADE assessment revealed the quality of the evidence in this meta-analysis ranged from very low to moderate.