Comparison between continuous posterior and lateral interscalene brachial plexus blockades for major shoulder surgery

BackgroundPostoperative pain relief after major shoulder surgery is extremely challenging. Continuous interscalene blockade is considered a well suited pain management technique for this type of surgery, but with technical difficulties. The aim of this study was to compare the efficacy and safety of continuous posterior and conventional lateral interscalene brachial plexus blockades.MethodsThis prospective randomized study included 40 patients who were radomally allocated into two equal groups (n = 20 patients), in the first group, continuous lateral interscalene blockade was done (Lateral Group), while continuous posterior interscalene was performed in the second group (Posterior Group). The measurement data were patient characteristics and surgical data, easiness of catheter insertion, onset of blockade, catheter insertion and total blockade times. Side effects encountered during blockade and postoperative efficacy of analgesia as well as patients satisfaction were also measured.ResultsThere was no significant difference as regards the onset of anesthesia in both groups. Block procedure time and catheter placement times were faster in the posterior group (6.6 ± 0.64 vs 9.6 ± 1.1 min; P < .05 and 1.6 ± 0.7 vs 4.3 ± 0.7 min; P < 0.05 respectively). Successful catheter insertion was higher in the posterior group (19 patients vs 15 patients in the lateral group). Easy catheter insertion were significantly higher in the posterior group (16 patients vs eight patients In the lateral group; P < 0.05). Technical adverse effects related to catheter insertion were significantly higher in the lateral group (nine patients vs only one patient in the posterior group; P < 0.05). Complications were comparable in both groups. Postoperative efficacy of analgesia and Patient's satisfaction about catheter placement was higher in the posterior group.ConclusionIn conclusion, we demonstrated a high success rate, low systemic and technical adverse effects, and better catheter compliance with continuous posterior interscalene blockade.