Infraclavicular Block: Decreased Incidence of Tourniquet Pain, Compared to Axillary Brachial Plexus Block?

Study Overview
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Brief Summary
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The purpose of this study is to determine whether the incidence of tourniquet pain is decreased if infraclavicular nerve block is administered, compared to axillary brachial plexus block, for surgical interventions at the level or distal to the elbow.

Detailed Description
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Pneumatic tourniquets are often used in orthopedic surgery to ensure bloodless surgical field. Besides their obvious positive effects, arterial tourniquets have some unfavorable properties. One of these is tourniquet pain, which can manifest in the presence of an otherwise adequate neuraxial or peripheral nerve block. If it develops, it is usually difficult to manage, and can be severe enough to necessitate conversion to general anaesthesia. In the past the incidence of tourniquet pain, associated with different nerve blocks has been estimated in clinical trials for which it was a secondary outcome measure. One recent meta-analysis addressed the question: is infraclavicular block (ICB) associated with a lesser incidence of tourniquet pain compared to other brachial plexus blocks. The studies selected by this meta-analysis used different types of nerve block. However it did not address the clinically relevant question: using standard techniques for ultrasound guided brachial plexus block (USgBPB) is the infraclavicular approach associated with a lesser incidence of tourniquet pain than the axillary approach? The following nerves contribute to the perception of tourniquet pain: musculocutaneous, radial, medial cutaneous brachial (MCBN) and intercostobrachial (ICBN). The potential advantage of the ICB over the axillary brachial plexus block (ABPB) in regards to tourniquet pain comes from anatomical reasons. In the pyramid shaped infraclavicular space the cords are much closer to each other; thus the likelihood of achieving effective MCBN and ICBN block is greater. The infraclavicular route has proven to result in an equally effective, reliable and safe block of the brachial plexus, compared to the axillary approach. We hypothesize that the incidence of tourniquet pain is less with infraclavicular block compared to axillary brachial plexus block. The aim of the study is, to compare the incidence and severity of tourniquet pain associated with ultrasound guided ICB and ABPB in patients undergoing orthopedic surgery at the level or distal to the elbow, with a tourniquet time longer than 45 minutes.

Official Title
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The Ultrasound Guided Infraclavicular Block: Decreased Incidence of Tourniquet Pain, Compared to Axillary Brachial Plexus Block?

Conditions
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Tourniquet Pain

Intervention / Treatment
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* Procedure: Ultrasound guided peripheral nerve block


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA I-III Orthopedic surgery at the level or distal to the elbow Expected tourniquet time > 45 min (K-wiring not suitable) Exclusion Criteria: Contraindication of regional anaesthesia, patient is allergic to local anesthetics Clinically significant cognitive impairment (Minimental state score < 24) Chronic pain syndrome Preexisting nerve damage in the operated arm (sensory or motor deficit) Axillary clearance in the past History of peripheral neuropathy) Pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Infraclavicular Block<br>The patient will be positioned supine. The operating limb may be positioned abducted or adducted by side depending on operator preference and patient factors. After standard preparation, the needle will be directed towards the target area using an in-plane, short-axis technique. Local anaesthetic (lidocaine 2% with epinephrine 1:200.000) will be injected posterior to the artery with the intention achieving the U shape, cranio-postero-caudal spread. Local anaesthetic will be deposited to the lateral and medial cords as well, if required. The total dose of the local anaesthetic will be 20-30 ml, as clinically indicated. | Procedure: Ultrasound guided peripheral nerve block<br>* Ultrasound guided peripheral nerve block<br>|
| Experimental: Axillary Brachial Plexus Block<br>The patient will be positioned supine with the operative upper limb extended, flexed at the elbow, rested on a pillow to expose the axilla. After standard preparation, the needle will be directed towards the target area using an in-plane, short-axis technique. All four nerves in the axillary region are being blocked. The local anesthetic (lidocaine 2% with epinephrine 1:200.000, 15-25 ml) will be divided among the four nerves as clinically indicated by the spread, but at least 3 ml applied to each nerve. | Procedure: Ultrasound guided peripheral nerve block<br>* Ultrasound guided peripheral nerve block<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Incidence of tourniquet pain |  | Intraoperative period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Onset time of tourniquet pain |  | Intraoperative period | 
| Severity of tourniquet pain | Mild tourniquet pain (no need for intervention*) Moderate tourniquet pain (need for fentanyl / additional sedation*) Severe tourniquet pain (requiring GA*) *: based on the clinical judgement of the responsible clinician (not a member of the study team) | Intraoperative period | 
| Incidence of adverse events | Vascular puncture or paresthesia during block placement | During block placement | 
| Block performance time | From commencing sterile preparation to completion of injection of local anaesthetic | During block placement | 
| Block onset time | From completed injection of local anaesthetic until loss of cold sensation in distribution of radial, ulnar, median and musculocutaneous nerve in the hand and forearm | 30 minutes after block placement | 
| Incidence of block failure | Presence of cold sensation in at least one distribute of radial, ulnar, median and musculocutaneous nerves in the hand and forearm at 30 min after completion of injection of local anaesthetic | 30 minutes after block placement | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Brachial plexus block, Regional anesthesia, Ultrasound