Effect of Perineural Dexmedetomidine on the ED50 Ropivacaine for Brachial Plexus Blocks in Pediatric Patients: a Randomized Trial

Dexmedetomidine can prolong the duration of local anesthetics, but the effect of perineural dexmedetomidine on the potency of ropivacaine for brachial plexus blocks in pediatric patients has not been investigated. This study was designed to determine the effect of perineural dexmedetomidine on ropivacaine for brachial plexus blocks in pediatric patients

Study Overview

• Status: Unknown
• Conditions: Dose-Response Relationship, Drug
• Intervention / Treatment: Drug: perineural dexmedetomidine

Detailed Description

150 children scheduled for arm and forearm surgery underwent supraclavicle brachial plexus blocks with ropivacaine guided by ultrasound visualisation were randomly assigned to one of the five groups: Group A (perineural ropivacaine), Group B (ropivacaine plus 0.5 mcg/kg dexmedetomidine), Group C (ropivacaine plus 1 mcg/kg dexmedetomidine), Group D (ropivacaine plus 1.5mcg/kg dexmedetomidine) and Group E (ropivacaine plus 2 mcg/kg dexmedetomidine). The primary endpoint was the minimum local anesthetic concentration (MLAC), which was determined using the Dixon up-and-down method. The secondary endpoints were the duration of analgesia and sedation

• Study Type: Interventional
• Enrollment (Anticipated): 160
• Phase: Phase 4

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 2 years to 6 years (Child)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• ASA I,II children, aged between 2 and 6 years, who were scheduled for arm and forearm surgery underwent supraclavicular brachial plexus blocks.

Exclusion Criteria:

• any subjects with neurological, neuromuscular, psychiatric, or blood clotting disorders, or known history of active and severe renal, hepatic, respiratory, or cardiac diseases, or known allergy to systemic or local anesthetics or dexmedetomidine

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: saline (Group A); perineural ropivacaine	Drug: perineural dexmedetomidine; Children scheduled for arm and forearm surgery underwent supraclavicle brachial plexus blocks with ropivacaine and dexmedetomidine guided by ultrasound visualisation were randomly assigned five groups: Group A (perineural ropivacaine), Group B (ropivacaine plus 0.5 mcg/kg dexmedetomidine), Group C (ropivacaine plus 1 mcg/kg dexmedetomidine), Group D (ropivacaine plus 1.5mcg/kg dexmedetomidine) and Group E (ropivacaine plus 2 mcg/kg dexmedetomidine). In each group, children received a certain concentration of ropivacaine which adjusted by the "Dixon up-and-down method for supraclavicle brachial plexus. The first child received 0.2% ropivacaine , and the concentration of ropivacaine varied by 0.1% according to the up-and-down method. The primary endpoint was the minimum local anesthetic concentration (MLAC).
Active Comparator: 0.5 mcg/kg dexmedetomidine (Group B); (perineural ropivacaine plus 0.5 mcg/kg dexmedetomidine),	Drug: perineural dexmedetomidine; Children scheduled for arm and forearm surgery underwent supraclavicle brachial plexus blocks with ropivacaine and dexmedetomidine guided by ultrasound visualisation were randomly assigned five groups: Group A (perineural ropivacaine), Group B (ropivacaine plus 0.5 mcg/kg dexmedetomidine), Group C (ropivacaine plus 1 mcg/kg dexmedetomidine), Group D (ropivacaine plus 1.5mcg/kg dexmedetomidine) and Group E (ropivacaine plus 2 mcg/kg dexmedetomidine). In each group, children received a certain concentration of ropivacaine which adjusted by the "Dixon up-and-down method for supraclavicle brachial plexus. The first child received 0.2% ropivacaine , and the concentration of ropivacaine varied by 0.1% according to the up-and-down method. The primary endpoint was the minimum local anesthetic concentration (MLAC).
Active Comparator: 1 mcg/kg dexmedetomidine (Group C); (perineural ropivacaine plus 1 mcg/kg dexmedetomidine)	Drug: perineural dexmedetomidine; Children scheduled for arm and forearm surgery underwent supraclavicle brachial plexus blocks with ropivacaine and dexmedetomidine guided by ultrasound visualisation were randomly assigned five groups: Group A (perineural ropivacaine), Group B (ropivacaine plus 0.5 mcg/kg dexmedetomidine), Group C (ropivacaine plus 1 mcg/kg dexmedetomidine), Group D (ropivacaine plus 1.5mcg/kg dexmedetomidine) and Group E (ropivacaine plus 2 mcg/kg dexmedetomidine). In each group, children received a certain concentration of ropivacaine which adjusted by the "Dixon up-and-down method for supraclavicle brachial plexus. The first child received 0.2% ropivacaine , and the concentration of ropivacaine varied by 0.1% according to the up-and-down method. The primary endpoint was the minimum local anesthetic concentration (MLAC).
Active Comparator: 1.5 mcg/kg dexmedetomidine (Group D); (perineural ropivacaine plus 1.5mcg/kg dexmedetomidine)	Drug: perineural dexmedetomidine; Children scheduled for arm and forearm surgery underwent supraclavicle brachial plexus blocks with ropivacaine and dexmedetomidine guided by ultrasound visualisation were randomly assigned five groups: Group A (perineural ropivacaine), Group B (ropivacaine plus 0.5 mcg/kg dexmedetomidine), Group C (ropivacaine plus 1 mcg/kg dexmedetomidine), Group D (ropivacaine plus 1.5mcg/kg dexmedetomidine) and Group E (ropivacaine plus 2 mcg/kg dexmedetomidine). In each group, children received a certain concentration of ropivacaine which adjusted by the "Dixon up-and-down method for supraclavicle brachial plexus. The first child received 0.2% ropivacaine , and the concentration of ropivacaine varied by 0.1% according to the up-and-down method. The primary endpoint was the minimum local anesthetic concentration (MLAC).
Active Comparator: 2 mcg/kg dexmedetomidine (Group E); (perineural ropivacaine plus 2 mcg/kg dexmedetomidine)	Drug: perineural dexmedetomidine; Children scheduled for arm and forearm surgery underwent supraclavicle brachial plexus blocks with ropivacaine and dexmedetomidine guided by ultrasound visualisation were randomly assigned five groups: Group A (perineural ropivacaine), Group B (ropivacaine plus 0.5 mcg/kg dexmedetomidine), Group C (ropivacaine plus 1 mcg/kg dexmedetomidine), Group D (ropivacaine plus 1.5mcg/kg dexmedetomidine) and Group E (ropivacaine plus 2 mcg/kg dexmedetomidine). In each group, children received a certain concentration of ropivacaine which adjusted by the "Dixon up-and-down method for supraclavicle brachial plexus. The first child received 0.2% ropivacaine , and the concentration of ropivacaine varied by 0.1% according to the up-and-down method. The primary endpoint was the minimum local anesthetic concentration (MLAC).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
the minimum local anesthetic concentration (MLAC)	For each patient, the target concentration of perineural ropivacaine was determined using the modified Dixon's up-and-down method starting with 0.20% in each group, varied with 0.1% as a step size. Increasing or decreasing the target concentration of perineural ropivacaine was determined by the response of the previous child in the same group. The response of each child was observed for 60 s after the skin incision and evaluated as 'successful' or 'unsuccessful.' 'Unsuccessful' was recorded when skin incision caused motor responses or change in hemodynamic parameters (heart rate and mean blood pressure) more than 20% of the preincision values. If the response was determined to be unsuccessful, the concentration of perineural ropivacaine given to the next patient would be increased by 0.1%. If it was successful, the concentration of caudal levobupivacaine given to the next patient would be decreased by 0.1%	up to 30 minutes after brachial plexus blocks
Postoperative pain	The Face, Legs, Activity, Cry, Consolability scale or FLACC scale is a measurement used to assess pain for children between the ages of 2 months and 7 years or individuals that are unable to communicate their pain. The scale is scored in a range of 0-10 with 0 representing no pain, 1-3 representing mild uncomfortable, 4-6 representing moderate pain, 7-10 representing high-level pain or/and uncomfort. The FLACC scale was evaluated at 6 and 12 hours postoperatively, and scale of ≥4 points was regarded as an inadequate analgesia and was managed with 10 mg/kg of ibuprofen by mouth every 6 h as required	up to 12 hours after brachial plexus blocks
The sedation status	Sedation status was evaluated by a attending anesthesiologists with a 6-point sedation scale, which was modified from the Modified Observer Assessment of Alertness and Sedation Scale (MOAA/S). The MOAA/S scale was evaluated at 6 and 12 hours postoperatively 0 Does not respond to a noxious stimulus; Does not respond to mild prodding or shaking; Responds only after mild prodding or shaking; Responds only after name is called loudly or repeatedly; Lethargic response to name-spoken in normal tone; Appears asleep, but responds readily to name-spoken in normal tone; Appears alert and awake, responds readily to name-spoken in normal tone	up to 12 hours after brachial plexus blocks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
pulse oximetry	Significant Oxyhemoglobin desaturation was defined as < 90%	up to 12 hours after brachial plexus blocks
heart rate	Bradycardia was defined as a reduction in heart rate more than 20% from the baseline values	up to 12 hours after brachial plexus blocks
noninvasive arterial blood pressure	Hypotension was defined as a reduction in systolic blood pressure more than 20% from the baseline values	up to 12 hours after brachial plexus blocks

Collaborators and Investigators

• Sponsor: Guangzhou Women and Children's Medical Center

Study record dates

Study Major Dates

• Study Start: September 1, 2016
• Primary Completion (Anticipated): December 1, 2017

Study Registration Dates

• First Submitted: May 16, 2016
• First Submitted That Met QC Criteria: May 19, 2016
• First Posted (Estimate): May 24, 2016

Study Record Updates

• Last Update Posted (Estimate): May 24, 2016
• Last Update Submitted That Met QC Criteria: May 19, 2016
• Last Verified: May 1, 2016

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Analgesics, Non-Narcotic; Adrenergic alpha-2 Receptor Agonists; Adrenergic alpha-Agonists; Adrenergic Agonists; Hypnotics and Sedatives; Dexmedetomidine
• Other Study ID Numbers: Wzhang05