To assess the clinical application of low-dose dexmedetomidine combined with propofol for sedation in pediatric outpatient MRI.

From January 2019 to March 2019, three hundred children who needed sedation for outpatient MRI in Guangzhou Women and Children's Medical Center were randomly divided into three groups: chloral hydrate sedation group (group H, oral take 10% chloral hydrate sedation), propofol sedation group (group P, propofol iv), and low-dose dexmedetomidine combined with propofol sedation group (group DP, dexmedetomidine 0.3 μg/kg iv + propofol iv), 100 cases in each group. The success rate of sedation, sedation effect, incidence of vomiting, agitation and respiratory inhibition were compared among the three groups.

The sedation success rate of group P and group DP was significantly higher than that of group H (χ²=18.560, P<0.001), while the incidence of vomiting and agitation was significantly lower (χ²=54.224, 17.023; P<0.001, 0.001). There were no significant differences in the incidence of respiratory depression and the number of cases requiring respiratory support among the three groups (χ²=1.049, 1.798; P=0.591, 0.407). The number of cases requiring propofol was significantly less in group DP than in group P during the sedation (χ²=67.520, P<0.001).The sedation onset time and recovery time and discharge time of group P and group DP were significantly shorter than those of group H (F=634.100, 243.800, 42.930, all P<0.001).

Low-dose dexmedetomidine combined with propofol intravenous sedation for MRI examination in pediatric outpatient clinics has such advantages as fast onset, fewer adverse reactions, high safety, quick recovery, and can be widely used in pediatric sedation.