Determination of the ED₉₅ of intranasal sufentanil combined with intranasal dexmedetomidine for moderate sedation during endoscopic ultrasonography

Background: Sedation during endoscopic ultrasonography (EUS) poses many challenges and moderate-to-deep sedation are often required. The conventional method to preform moderate-to-deep sedation is generally intravenous benzodiazepine alone or in combination with opioids. However, this combination has some limitations. Intranasal medication delivery may be an alternative to this sedation regimen.

Aim: To determine, by continual reassessment method (CRM), the minimal effective dose of intranasal sufentanil (SUF) when combined with intranasal dexmedetomidine (DEX) for moderate sedation of EUS in at least 95% of patients (ED₉₅).

Methods: Thirty patients aged 18-65 and scheduled for EUS were recruited in this study. Subjects received intranasal DEX and SUF for sedation. The dose of DEX (1 μg/kg) was fixed, while the dose of SUF was assigned sequentially to the subjects using CRM to determine ED₉₅. The sedation status was assessed by modified observer's assessment of alertness/sedation (MOAA/S) score. The adverse events and the satisfaction scores of patients and endoscopists were recorded.

Results: The ED₉₅ was intranasal 0.3 μg/kg SUF when combined with intranasal 1 μg/kg DEX, with an estimated probability of successful moderate sedation for EUS of 94.9% (95% confidence interval: 88.1%-98.9%). When combined with intranasal 1 μg/kg DEX, probabilities of successful moderate sedation at each dose level of intranasal SUF were as follows: 0 μg/kg SUF, 52.8%; 0.1 μg/kg SUF, 75.4%; 0.2 μg/kg SUF, 89.9%; 0.3 μg/kg SUF, 94.9%; 0.4 μg/kg SUF, 98.0%; 0.5 μg/kg SUF, 99.0%.

Conclusion: The ED₉₅ needed for moderate sedation for EUS is intranasal 0.3 μg/kg SUF when combined with intranasal 1 μg/kg DEX, based on CRM.