Abstract
Objective: To assess the influence of alkalinization of lignocaine on pain character during open carpal tunnel release. Methodology: This prospective, randomized and double blind investigation included 103 subjects, of both gender, aged 51-63 years, classed I-II physical status according to the American society of Anesthesiologists and scheduled for elective outpatient open carpal tunnel decompression under local anesthesia at Prince Hashim Military Hospital, Zarqa, Jordan from December 2015 to June 2017. Participants were divided into two groups; Group I (n=50) patients were administered plain lignocaine 2%(5 ml) mixed with 5 ml of isotonic normal saline and Group II (n=53) patients were administered alkalinized lignocaine 2% (5 ml of plain lignocaine 2%) mixed with 1 ml of sodium bicarbonate 8.4%(1mmol/1 ml) and 4 ml of normal saline. Local anesthesia was achieved at the incision from proximal to distal direction. Infiltration pain was evaluated using a 0-10 numerical score of Likert verbal Analogue Scale after infiltration. Anesthesia satisfaction was scored on a scale from 1(least satisfied) to 5(most satisfied). Statistics were performed using ANOVA test.
Results: Total median pain score on local anesthetic infiltration was 3.9 (range 3.5-4.2) in group I, while it was 1.6 (range 1.3-1.9) in group II (P<0.05). Regarding satisfaction; 26 patients in group I (52%) had least satisfaction, while nine patients in group II (16.98%) had least satisfaction (P<0.05). Conclusion: Using lignocaine with sodium bicarbonate decreased the pain remarkably on infiltration in carpal tunnel release.

Key words: Alkalinization, infiltration, lignocaine, open carpal tunnel release.