Background: Subacromial decompression surgery is associated with significant postoperative pain. We compared the effect of intrascalene block (ISB) and sub-acromial bursa block (SBB) with simple opiate based analgesia

Methods: In a prospective, randomised controlled trial, fifty-three (n = 53) patients scheduled for arthroscopic subacromial decompression were randomised into three groups receiving Intrascalene block (n =19), Subacromial Bursa block (n =19) or neither of the two blocks (n =15 controls). Patients with cuff pathology were excluded. ISB was performed preoperatively with 20 mls of 1% Prilocaine and 10 mls of 0.5 % Bupivacaine. SBB was given with 20 mls of 0.5% Bupivacaine postoperatively. All patients received standardised general anaesthetic and postoperative analgesia. Pain, sickness and sedation scores were noted at 1, 2, 4, 8, 12 and 24 hours postoperatively. The postoperative consumption of morphine and the time when the first bolus of morphine was required were also noted.

Results: The visual analogue pain scores in the ISB and SBB group were lower than the control group in the first twelve hours postoperatively achieving statistical significance but there were no significant differences between the SBB and ISB groups. The controls consumed more morphine postoperatively (mean 32.3 mls) than SBB (21.21 mls) and ISB groups (14.00 mls) (p < 0.001). The time for first bolus was earlier in the controls (mean 30.2 mins) as compared to both SBB (72.7 mins) and ISB groups (105.8 mins) (p< 0.001). The oral analgesic intake was less in the SBB and ISB groups than the controls (p = 0.004), but there was no difference between the two treatment groups.

Conclusion: Whilst intrascalene block remains the gold standard where expertise is available for its administration, subacromial bursa block is a safe alternative in patients with intact rotator cuff undergoing arthroscopic subacromial decompression.