Transarterial block as an addition to a conventional catheter technique improves the axillary block

Abstract

Background: We have had favourable experience with a triple injection technique, combining an axillary catheter technique with a transarterial axillary block. This method has been used successfully for routine surgery and re‐implantation of fingers, hand or forearm. We hypothesized that with this technique, block onset time and effectiveness are better than with a conventional catheter technique, and designed a study comparing this new technique with a conventional single injection through a catheter. Methods: Fifty‐one adult patients were included in a prospective study. In all patients, a short axillary plexus catheter was positioned close to the median nerve. All patients had an injection through the catheter, while 26 of the patients had an additional injection behind, and in front of, the axillary artery. Sensory and motor block were tested continuously every minute for 29 min. Block success was recorded as onset time to analgesia, anaesthesia and complete motor block in the first 29 min. At 30 and 50 min, an analgesia block score was recorded. Results: The transarterial injection plus catheter method was more effective, with a higher success rate and faster onset, than the catheter method. Readiness for surgery with analgesia in the median, radial and ulnar nerves was achieved in the catheter group in 13 patients (52%) at a mean time of 20.8 min, and in the combined group in 21 patients (81%) at a mean time of 13.3 min (P < 0.05, P < 0.05). At 50 min the situation was 17 (68%) and 24 (92%), respectively (P < 0.05). Conclusion: The combined triple injection is faster and more effective than the catheter method alone.

MRI of axillary brachial plexus blocks

“…It was advanced parallel to the median nerve and anterior (superior) to the brachial-axillary artery by nerve stimulation guidance (Stimuplex DIG/HNS11; B. Braun). 4 Using an impulse width of 0.1 ms, a threshold range of 0.2 to 0.8 mA was accepted. The local anaesthetic dose for every patient in all groups was 40 ml of a 50 : 50 mixture of lidocaine 20 mg ml –1 and bupivacaine 5 mg ml –1 with 5.0 μg ml –1 adrenaline, giving a total dose of 400 mg lidocaine, 100 mg bupivacaine and 100 μg adrenaline.…”

“…Due to limited access to the MRI facility, we based the study on only 15 patients in each of the three groups. With an experienced block difference of almost 30% between single and triple injection 4 and a 5% significance level for one-sided tests, a statistical power of 74% was calculated. Data were described by mean, standard deviation and counts.…”

“…The first author of our study has developed a nonultrasound-guided axillary block method with three deposits. 4 Although our experience with this method has been favourable, 4 , 5 we have been challenged by the question of whether all the injections are necessary.…”