Description of the Brachial Plexus Block at the Humeral Head in Children: a Sono-anatomical Study

Study Overview
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Brief Summary
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the investigators are interested in assessing the feasibility and value of brachial plexus block at the level of the humeral head in children. As a first step, the investigators propose to carry out a sono-anatomical study to describe the plexus at this level, the distribution of nerves in relation to the axillary artery, and the description of bone and muscle structures.

Detailed Description
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Brachial plexus blocks below the clavicle provide anesthesia and analgesia of the upper limb for elbow, forearm and hand surgery. Among the techniques described, axillary and costo-clavicular blocks are most frequently used. In the axillary approach to the brachial plexus, the ulnar, median and radial nerves are in the direct vicinity of the axillary artery. However, there is considerable variability in the location of these nerves . What's more, the musculocutaneous nerve is most often distant from the other nerves of the plexus. These disadvantages are not encountered with the costo-clavicular technique, in which the nerves are brought together in the same diffusion space. On the other hand, this method does run the risk of pneumothorax and anesthesia of the phrenic nerve. In this context, the investigators have described the brachial plexus block at the level of the humeral head in adults, which enables practicians to work on nerves gathered around the axillary artery without any risk of phrenic or pulmonary damage4. In children, Small et al described a supra-clavicular approach, but Clayton et al, noting the high risk of pneumothorax, strongly advocated the axillary approach.

Official Title
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Description of the Brachial Plexus Block at the Humeral Head in Children: a Sono-anatomical Study

Conditions
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Anesthesia, Local, Brachial Plexus; Pressure

Intervention / Treatment
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* Other: Sono-anatomical Study


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patient ASA 1-2 aged 0 to 10 years scheduled surgery parental consent obtained Exclusion Criteria: Parental refusal to participate suspicion of local skin infection inability to place the limb in the position required for sonographic examination Upper limb malformation ASA III, IV Major surgery (cardiac, neurosurgery...) emergencies

Ages Eligible for Study
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Minimum Age: 1 Month
Maximum Age: 10 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| 0-2<br>children aged 0 to 2 years | Other: Sono-anatomical Study<br>* The arm is abducted (90°), externally rotated, with the forearm flexed over the arm (90°). A linear ultrasound probe (8-15 MHz) is placed in front of the humeral head, in a sagittal plane. Location begins at axillary level, vessels, nerves and humerus are identified, and the probe is moved medially to reach and identify the humeral head.<br>|
| 2-4<br>children aged 2 to 4 years | |
| 4-6<br>children aged 4 to 6 years | |
| 6-8<br>children aged 6 to 8 years | Other: Sono-anatomical Study<br>* The arm is abducted (90°), externally rotated, with the forearm flexed over the arm (90°). A linear ultrasound probe (8-15 MHz) is placed in front of the humeral head, in a sagittal plane. Location begins at axillary level, vessels, nerves and humerus are identified, and the probe is moved medially to reach and identify the humeral head.<br>|
| 8-10<br>children aged 8 to 10 years | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| description of the position of the nerves around the axillary artery | Hourly distribution of nerve structures around the axillary artery , expressed in degrees and measured with a protractor | through study completion, around 5 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| distance between anatomical structures | depth of diffusion spaces Skin-cartilage distance Cartilage thickness Skin-nerve distance Skin-to-vessel distance size of nerves all these measurements in centimeters | through study completion, around 5 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Brachial plexus