The effect of age on outpatient pediatric procedural sedation with intranasal dexmedetomidine and oral midazolam.

Procedural sedation for diagnostic examination is a common practice in children. The study aims to analyze the sedative effect and safety of intranasal dexmedetomidine combined with oral midazolam in outpatient pediatric procedural sedation across different age groups and to assess the incidence of sedation failure. From February 2021 to September 2021, children who underwent procedural sedation were retrospectively enrolled. The children were divided into 4 groups based on age: the infant group (0 to 1 year old), toddler group (1 to 3 years old), preschool group (3 to 6 years old), and school-age group (6 to 12 years old). Two-mcg/kg intranasal dexmedetomidine and 0.5-mg/kg oral midazolam were used for sedation. The sedation success rate after rescue, sedation success rate, onset time of sedation, and the sedation time were recorded. The incidence of adverse events and the risk factors for sedation failure were also analyzed. A total of 4758 patients were identified. After exclusion, 3149 patients were ultimately enrolled. The combination of 2-mcg/kg intranasal dexmedetomidine and 0.5-mg/kg oral midazolam resulted in a total success rate of 99.7% and a sedation success rate of 91.4%. The sedation success rate varied among the four groups: 90.2% in the infant group, 93.1% in the toddler group, 92.7% in the preschool group, and 78.4% in the school-age group. The sedation success rate was significantly lower in the school-age group compared to the other three groups (P < 0.001). The onset time of sedation was shorter in infant (22 min, IQR: 18-28 min, P < 0.001) and longer in the school-age group (30 min, IQR: 25-35 min, P < 0.05). Additionally, the infants had a longer sedation time (110 min, IQR: 90-135 min, P < 0.001) and a higher rate of delayed recovery (27.5%, all P < 0.001). The incidence of adverse events was low (4.70%), which bradycardia (2.03%) being the most common. Age (0-1 year and > 6 years), weight, ASA class II, and history of failed sedation were identified as risk factors of sedation failure.   Conclusion: Intranasal administration of 2-mcg/kg dexmedetomidine combined with oral administration of 0.5-mg/kg midazolam was found to be efficient and safety for pediatric procedural sedation. Different age groups of children exhibited distinct sedation characteristics, and age was identified as a risk factor affecting the efficacy of sedation. What is Known: • Procedural sedation for diagnostic examination is a common practice in children. • The combination of dexmedetomidine with midazolam can improve sedative effects. What is New: • The success rate of sedation using a combination of 2-mcg/kg intranasal dexmedetomidine and 0.5-mg/kg oral midazolam was significantly lower in school-age children as compared to infants, toddlers, and preschoolers. • The onset time of sedation increased with age, and the sedation time was found to be longer in infant patients.