Objective
The study was designed to compare the efficacy of dexmedetomidine whether given intramuscular or intravenous for pediatric MRI sedation.
Subjects and methods
Ninety children between the ages of 2 and 8 years with ASA physical status I–II, scheduled for elective MRI, were enrolled in a double blind, comparative randomized study. Patients assigned into two equal groups. Group DV, sedation was performed using IV dexmedetomidine hydrochloride; a loading dose of 1 μg/kg administered over 10 min followed by a continuous infusion at 1 μg/kg/h. Group DM where the patient received IM dexmedetomidine 3 μg/kg. Primary endpoints included incidence of failed sedation and the requirement of midazolam supplementation. Secondary endpoints were time to sedation, duration of sedation, discharge time, and hemodynamic status.
Results
The sedation failure rate was significantly higher in the DV group (40%) in comparison with the DM group (20%) ( = 0.04). Also, the use of rescue midazolam was significantly higher in the VD group (0.37 ± 0.47 mg) in comparison to the DM group (0.17 ± 0.35 mg) ( = 0.025). The onset of satisfactory sedation was significantly shorter in DV group in comparison to DM group (7.93 ± 0.884 vs. 16.87 ± 4.49). Also, the discharge time was significantly less in the DV group (32.27 ± 3.04 min) in comparison to DM group (41.87 ± 5.80 min). Patients in DV group had significantly lower MBP compared to patients in DM group after receiving dexmedetomidine ( < 0.05). Although the HR decreased in both groups during the MRI study, the decrease was statistically significant in the DV group compared to the DM group in the period extended from the 2nd to 35th min ( < 0.05).
Conclusion
In pediatric MRI sedation, although IM dexmedetomidine does have a late sedation onset; it reduces the sedation failure rate, the need for supplement sedation and the incidence of hemodynamic instability associated with IV dexmedetomidine.