PURPOSE: To assess whether 5 mL would not be less effective than 10 mL when performing a suprascapular nerve block, regarding shoulder function and quality of life in primary adhesive capsulitis. METHODS: This is a pilot study of a randomized, controlled, double-blind clinical trial conducted at a single center. Patients with AC characterized by constant pain and restricted movements in anterior elevation, 0°/90° external rotation, and internal rotation were selected. Two groups were randomly selected. In group I, a dose of 10 mL of bupivacaine was applied, while in group II, only 5 mL, in four weekly blocks. Sealed and sequentially numbered envelopes were used. The SF-36 and DASH questionnaires were applied in five moments. The t-Student test was used to compare the means, with a probability of rejecting null hypothesis of 5%. RESULTS: There were 17 participants with primary AC, seven in group I and 10 in group II. The average age was 54.30 and 50.43 years in the 5 mL and 10 mL groups, respectively. There were no differences when the means were compared by DASH: T0 (p = 0.074)
T2 (p = 0.285)
T4 (p = 0.333)
T8 (p = 0.392), and T12 (p = 0.453). As for the SF-36, there were sparse differences in T2 in the domains of vitality (p = 0.006) and social aspects (p = 0.036) in favor of group I, and in the general health status domain in T8, in favor of group II (p = 0.033). CONCLUSION: The volume of 5 mL is not less effective than 10 mL when performing SSNB in the treatment of primary adhesive capsulitis.