Oral midazolam combined with brief inhaled sevoflurane provides effective sedation for paediatric magnetic resonance imaging

To evaluate the efficacy and safety of a non-invasive sedation protocol combining oral midazolam solution with a brief inhaled sevoflurane for outpatient pediatric magnetic resonance imaging (MRI) examinations. Prospective, single-center, randomized controlled trial with blinded outcome assessment. Outpatient pediatric MRI unit at Xi’an International Medical Center Hospital, China. 104 children aged 1–6 years, ASA physical status I-II, scheduled for single-site MRI under sedation. Patients were randomized to: (1) oral midazolam (0.82 mg/kg) plus inhaled sevoflurane (MS group, n = 35); (2) intranasal dexmedetomidine (3 µg/kg) plus inhaled sevoflurane (DS group, n = 34); (3) intranasal dexmedetomidine monotherapy with sham inhalation (DA group, n = 35). Sedation success rate (proportion achieving MRI scan without rescue sedation). Sedation success was 91.4% (32/35) in MS, 47.1% (16/34) in DS, and 25.7% (9/35) in DA groups. Rescue sedation was required in 8.6%, 52.9%, and 74.3% of cases, respectively. Patient behavior scores during premedication were significantly better in MS vs. DS or DA. Mask acceptance was higher in MS and DA vs. DS. Median time from premedication to scan start was 32, 27, and 30 min, respectively. Recovery time was comparable across groups. Adverse events were mild and infrequent, with hypoxemia (SpO₂ <95%) occurring in 8.6% (MS) and 5.9% (DS). No serious adverse events occurred. Oral midazolam combined with brief inhaled sevoflurane demonstrated higher sedation success rates compared with the intranasal dexmedetomidine-based regimens tested in this study for pediatric MRI.