Monday, May 11, 2020

Efficacy and Safety of Ultrasound-Guided Supraclavicular Brachial Plexus Block during Angioplasty of Dysfunctional Arteriovenous Access: A Prospective, Randomized Single-Center Clinical Trial


Clinical question

Is ultrasound-guided supraclavicular brachial plexus block (BPB) helpful in reducing pain prior to angioplasty of dysfunctional arteriovenous (AV) access?

Take-away point
Patients randomized to supraclavicular BPB prior to intervention on their AV access showed lower average pain scores with better patient satisfaction compared to the control group with no major immediate or delayed complications.

Reference
Heo, S., Won, J. H., Kim, J., Kim, J. Y. & Joe, H. B. Efficacy and Safety of Ultrasound-Guided Supraclavicular Brachial Plexus Block during Angioplasty of Dysfunctional Arteriovenous Access: A Prospective, Randomized Single-Center Clinical Trial. J. Vasc. Interv. Radiol. 31, 236–241 (2020).

Click here for abstract

Study design
Single-center prospective clinical trial of 80 participants between November 2016 and February 2018 randomized to either ultrasound-guided supraclavicular BPB or no regional anesthesia. Primary endpoints included pain assessment and patient satisfaction evaluation. Secondary endpoints included AV access patency at 6-month follow up as well as short- and long-term complications.

Funding source
N/A

Setting
Departments of Radiology and Anesthesiology and Pain Medicine at Ajou University School of Medicine, Suwon, Korea




Figure 2. Ultrasound-guided BPB procedure. The 23-gauge needle is first advanced to the inferior border of the brachial plexus (a), and 15 ml of anesthetic mixture is injected, resulting in superficially floating plexus bundle (b). The needle is then directed to the superior border of the brachial plexus, injecting another 15 ml of mixture (c). The procedure results in complete encasement of the brachial plexus by the injected mixture (d). M = medial; L = lateral.

Summary


Percutaneous balloon angioplasty of AV access is often painful. While moderate sedation can help alleviate pain during intervention, these medications can be associated with respiratory depression in an otherwise high-risk patient population. This study was developed to evaluate the anesthetic effect and safety of ultrasound-guided supraclavicular BPB for pain control during angioplasty of dysfunctional dialysis access—a method frequently utilized during upper extremity surgery.

Eighty participants with either insufficient flow or no flow in their upper extremity AV fistula or graft were randomized to supraclavicular BPB prior to angioplasty versus a control group. All procedures including BPB and dialysis access angioplasty were performed by the same two interventional radiologists who were not involved in the randomization process. There was no significant difference between groups regarding the reason for dialysis access dysfunction (P= .29) or the type/location of access (P=.82).

A mixture of 10 cc 0.75% ropivacaine, 10 cc of 2% lidocaine and 10 cc of normal saline was utilized for the purposes of supraclavicular BPB administered via the “double injection” technique at both the inferior and superior aspects of the plexus under ultrasound guidance. Procedure success was determined by motor and sensory changes to 0. Time to full block as well as time to recovery from motor and sensory deficit was recorded. Pain in the control group was managed with intravenous administration of 50 mg Tramadol and 5-10 cc of 2% lidocaine subcutaneous injection at the puncture site.

Procedure-related pain was evaluated by the Visual Analogue Scale from 0 (no pain) to 10 (unbearable pain) in both groups. Patient satisfaction was evaluated by a grade from 1 (not satisfied) to 3 (satisfied). Six-month follow up was performed either in outpatient clinic or over the phone.

All BPB procedures were technically successful with an average time to complete neurologic deficit of 10.7 +/- 5.1 minutes. The average neurologic recovery time from BPB was 7 hours and 56 minutes. The visual analogue pain scale was significantly lower (P < .001) and participant satisfaction was significantly higher (P < .001) in the BPB group compared to the control. Six-month patency of the AV access was not significantly different in the two groups (P = .59). There were no major complications.

Commentary


This is the first prospective randomized trial to evaluate the safety and efficacy of supraclavicular BPB prior to angioplasty of dysfunctional dialysis access elucidating the benefits for pain management during intervention. The authors successfully demonstrated reduction in pain score and improvement in patient satisfaction with supraclavicular BPB without short- or long-term complications.

In this study protocol, supraclavicular BPB was consistently performed by the same highly experienced interventional radiologists prior to angioplasty. Similar protocols may be difficult to simulate in institutions where nerve blocks are traditionally performed by anesthesiologists who may not be readily available for assistance in the immediate periprocedural period with potential for delay of intervention. Conversely, supraclavicular BPB performed by less experienced interventional radiologists may prolong total intraprocedural time.

The primary method of intraprocedural pain management in the control group was intravenous tramadol. Since many institutions continue to utilize moderate sedation with intravenous fentanyl and versed during dialysis access interventions, direct comparison of the authors’ protocol for supraclavicular BPB and moderate sedation may be beneficial in future studies.

The authors describe potential limitations including use of a single mixture/concentration of anesthetic in the BPB group as well as potential bias resulting in prolonged recovery from motor and sensory deficit. As demonstrated by the authors, diligent patient education and monitoring must be maintained in the post-procedural period to prevent injury from nerve deficit if supraclavicular BPB is utilized.

Post Author
Teodora Bochnakova MD
Assistant Professor
Department of Interventional Radiology
Oregon Health and Science University, Portland, OR
@T_bochnakova

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