Efficacy of Clonidine as an Additive on the Duration of Action of Brachial Plexus Block Performed Under Ultrasound and Nerve Locator Guidance: A Prospective Randomized Study.

BACKGROUND

Clonidine, an alpha agonist, when added to local anesthetics in different regional and neuraxial blocks reduces the onset time, improves the efficacy, and increases the duration of postoperative analgesia.

AIMS

This study evaluated the effect of bupivacaine clonidine combination in ultrasound and nerve locator-guided supraclavicular brachial plexus block for upper limb surgeries.

SETTINGS AND DESIGN

This was a prospective, randomized, controlled, double-blind study carried out in a tertiary care center in South India on 50 patients with American Society of Anesthesiologists (ASA) physical status classes I and II undergoing elective upper limb surgery under supraclavicular brachial plexus block.

MATERIALS AND METHODS

Eligible participants were randomized equally to either Group B who received 20 ml of bupivacaine and 7 mL of 2% lignocaine or Group C who received 20 ml of bupivacaine, 7 ml of 2% lignocaine, and 100 μg of clonidine.

STATISTICAL ANALYSIS

Continuous outcome variables were tested for statistical significance using Student's -test, and Mann-Whitney U-test was used for outcomes that were nonnormally distributed. Categorical variables were compared using Fisher's exact test. <0.05 was considered as statistically significant.

RESULTS

The onset of sensory and motor blockade was significantly faster ( < 0.05) in Group C compared to Group B. The duration of sensory and motor block and the duration of analgesia were significantly longer in Group C ( < 0.001). The sedation in Group C patients was significantly more ( < 0.05) when compared to Group B, but none of the sedation scores exceeded 3 on the Ramsay sedation score. Hemodynamic parameters did not differ between groups ( > 0.05).

CONCLUSION

The inclusion of 100 μg of clonidine with bupivacaine in ultrasound-guided supraclavicular brachial plexus blocks prolongs both sensory and motor blockade. It also provides significant postoperative analgesia and mild sedation which is beneficial in the immediate stressful postoperative period.