Using intranasal dexmedetomidine with buccal midazolam for magnetic resonance imaging sedation in children: A single-arm prospective interventional study

Abstract

Objective: Although numerous intravenous sedative regimens have been documented, the ideal non-parenteral sedation regimen for magnetic resonance imaging (MRI) has not been determined. This prospective, interventional study aimed to investigate the efficacy and safety of buccal midazolam in combination with intranasal dexmedetomidine in children undergoing MRI.

Methods: Children between 1 month and 10 years old requiring sedation for MRI examination were recruited to receive buccal midazolam 0.2 mg⋅kg^-1 with intranasal dexmedetomidine 3 μg⋅kg^-1. The primary outcome was successful sedation following the administration of the initial sedation regimens and the completion of the MRI examination.

Results: Sedation with dexmedetomidine-midazolam was administered to 530 children. The successful sedation rate was 95.3% (95% confidence interval: 93.5-97.1%) with the initial sedation regimens and 97.7% (95% confidence interval: 96.5-99%) with a rescue dose of 2 μg⋅kg^-1 intranasal dexmedetomidine. The median sedation onset time was 10 min, and a significant rising trend was observed in the onset time concerning age (R = 0.2491, P < 0.001). The wake-up and discharge times significantly correlated with the duration of the procedure (R = 0.323, P < 0.001 vs. R = 0.325, P < 0.001). No oxygen deficiency nor medication intervention due to cardiovascular instability was observed in any of the patients. History of a prior failed sedation was considered a statistically significant risk factor for failed sedation in the multivariate logistic regression model [odds ratio = 4.71 (95% confidence interval: 1.24-17.9), P = 0.023].

Conclusion: In MRI examinations, the addition of buccal midazolam to intranasal dexmedetomidine is associated with a high success rate and a good safety profile. This non-parenteral sedation regimen can be a feasible and convenient option for short-duration MRI in children between 1 month and 10 years.

Keywords: children; dexmedetomidine; magnetic resonance imaging; midazolam; sedation.

FIGURE 1

Flow diagram of sedation for magnetic resonance imaging.

FIGURE 2

Percentage of UMSS Scores at Target 3 to 4. University of Michigan Sedation Scores (UMSS) range from 3 to 4 with four different age categories. In the first 60 min after drug administration, 95.5% of children with UMSS reached the target of deep sedation (3 to 4). The percentages of UMSS in deep sedation for 5, 10, 15, and 20 min were significantly different among the four age groups (P = 0.001, P = 0.002, P < 0.001, and P < 0.001, respectively). There was a significant increasing trend in the onset time with age in months (R = 0.249, P < 0.001). The wake-up time and discharge time were significantly correlated with duration of procedure (R = 0.323, P < 0.001 vs. R = 0.325, P < 0.001). **P < 0.01.

FIGURE 3

Time to resume normal activities and side effects by the post-sedation survey. (A) Time to resume normal activities after drug administration in different age groups. The median (interquartile range) time to resume normal activities was 5.5 (4–8) h. No statistical differences were observed among different age groups for the time to resume normal activities (P = 0.724). (B) Side effects by the parental feedback in the follow-up survey.