Interscalene brachial plexus (ISB) block with dexmedetomidine (DEX) showed an improved visual analog pain scale (VAS) and patient satisfaction within 48 h after arthroscopicrotator cuff repair. ISB with DEX showed a reversed mean plasma IL-6 and IL-8 compared to VAS within this period with a delayed rebound pain.
Interscalene brachial plexus block (ISB) is one of the most commonly used regional blocks in relieving postoperative pain in arthroscopic rotator cuff repair. Dexmedetomidine (DEX) is an alpha 2 agonist which can enhance the effect of regional blocks. The aim of this study was to compare the results of DEX combined with ISB with ISB alone on postoperative pain, satisfaction, and pain-related cytokines within the first 48 hours after arthroscopic rotator cuff repair.
Fifty patients with rotator cuff tears who had undergone arthroscopic rotator cuff repair were enrolled in this single center, double blinded randomized controlled trial study. The 25 patients randomly allocated to group 1 received ultrasound-guided ISB using a mixture of 1 ml (100 µg) DEX and 8 ml 0.75% ropivacaine, preemptively. The other 25 patients to group to group 2 underwent ultrasound-guided ISB alone using a mixture of 1 ml normal saline and 8 ml ropivacaine. Visual analog pain scale (VAS) and patient satisfaction (SAT) were checked within postoperative 48 h. The plasma interleukin (IL) -6, -8, -1ß, Cortisol, and Substance P were also measured within postoperative 48 h.
Group 1 showed a significantly lower mean VAS, and a significantly higher mean SAT at postoperative 1, 3, 6, 12, and 18 h than group 2. Group 1 showed a significantly lower mean plasma IL-6 at postoperative 1, 6, 12, and 48 h, and a significantly lower mean IL-8 at 1, 6, 12, 24, 48 h than group 2. The mean timing of rebound pain in group 1 was significant later than that in group 2 (12.7 h>9.4 h, p=0.006).
Ultrasound-guided ISB with DEX showed a reversed mean plasma IL-6 and IL-8 compared to VAS within postoperative 48 h with a delayed rebound pain.
Level of evidence: Level I, randomized controlled trial.