The median effective dose (ED50) and ED95 of intranasal dexmedetomidine as a single bolus have not been described for sedation in children undergoing transthoracic echocardiography (TEE) study. This information is important to compare agents and to determine the most effective sedative dose. The investigators performed a two-stage study to determine the ED50 and the ED95 of intranasal dexmedetomidine to investigate age-related differences in participants undergoing transthoracic echocardiography study.
The investigators performed a two-stage study to determine the ED50 and the ED95 of intranasal dexmedetomidine in children undergoing transthoracic echocardiography study. In phase 1, 120 participants were randomized in a Dixon-Massey study to describe the minimum local sedative dose. In phase 2, a further 160 participants were randomly allocated to receive sedation with doses in the upper dose-response range to define the ED95
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
TRIPLE
Enrollment
320
Phase 1, Children received a bolus of intranasal dexmedetomidine which adjusted by the "Dixon up-and-down method for TEE study. The first child received 2.5 mcg/kg of intranasal dexmedetomidine dose (100mcg/ml), and the dose varied by 0.1 mcg/kg according to the up-and-down method Phase 2 was a dose-escalation study. After interim analysis of the phase 1 results, four dose levels above the calculated ED50 were defined. Dose spacing was set at 0.25 mcg/kg of intranasal dexmedetomidine consistent with the re-estimated standard deviation (SD).
Department of Anesthesiology of Guangzhou Women and Children's Medical Center
Guangzhou, Guangdong, China
The ED50 doses for intranasal dexmedetomidine
Phase 1: The starting dose of dexmedetomidine was 2.5 mcg/kg. These doses varied by 0.1 mcg/kg, according to the up-and-down method 18. If the detected MOAA/S score was \>3 within 45 minutes after intranasal administration, or clinically adequate diagnostic-quality images could not be acquired, sedation was considered a failure; and the dexmedetomidine dose was increased by 0.1 mcg/kg in the next patient of the same age group. In contrast, if the detected MOAA/S score was ≤3 and the acquisition of clinically adequate diagnostic-quality images was possible, the sedation was considered successful; and the dexmedetomidine dose was decreased by 0.1 mcg/kg in the next patient o
Time frame: up to 0.5 hours after transthoracic echocardiography
The ED95 doses for intranasal dexmedetomidine
Phase 2 was a dose-escalation study. After interim analysis of the phase 1 results, four dose levels above the calculated ED50 were defined. Dose spacing was set at 0.3 mcg/kg of intranasal dexmedetomidine consistent with the re-estimated standard deviation (SD). Defined levels were set at about 2.5, 2.75, 3.0, and 3.25 mcg/kg of intranasal dexmedetomidine. Criteria for success and failure were identical to those in phase 1. Successful sedation was defined as a MOAA/S score between 0-3 and allowed the acquisition of clinically adequate diagnostic-quality images, while failure was defined as a MOAA/S score \>3 within 45 minutes or clinically adequate diagnostic-quality images could not be acquired
Time frame: up to 0.5 hours after transthoracic echocardiography
Score of physical movement
Movement score was recorded by sonographers who were blinded to the sedative regimen. 1. No movement 2. Occasional, slight movement 3. Frequent, slight movement 4. Vigorous movement limited to extremities 5. Vigorous movement, including torso and head
Time frame: up to 0.5 hours after transthoracic echocardiography
sedation induction time
Successful sedation was defined as an MOAA/S of between 0 and 3, and sedation induction time was defined as the time from drug administration to the onset of satisfactory sedation
Time frame: up to 2 hours after drug administration
Wake -up time
Children were classified as awake if the MOAA/S was between 4 and 6. Wake -up time was defined as the time from successful sedation until the time that the child awoke
Time frame: up to 2 hours after drug administration
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