Abstract :
Background: The brachial plexus block is an easy and relatively safe procedure for upper limb surgeries
though there are different approaches to it, it is a block of roots, divisions and cords of the brachial plexus,
out of which supraclavicular approach is most widely used method for anaesthesia and preoperative pain
management in surgery below shoulder joint. It is performed at the trunk level where the plexus is presented
most compactly. Another advantage is that it can be performed with the patient’s arm in any position to
provide excellent anaesthesia for elbow, forearm and hand surgery.
Various local anaesthetic agents are used for Brachial Plexus Block but most commonly used drugs are;
Bupivacaine, and Lignocaine. Bupivacaine is long acting whereas Lignocaine is short acting drug. Novel
adjuncts studied to date include butorphanol, buperonorphine, dexamethasone, Clonidine, Neostigmine,
Tramadol, Midazolam, Dexmedetomidine etc.
Dexmedetomidine is an anxiolytic sedative and analgesic agent, it is a selectivea2 – adrenoreceptor agonist
and is approximately 8 times more potent than clonidine. It was superior to clonidine also in quality for
anesthesia in tourniquet tolerance, and postoperative analgesia and it is notable for its ability to provide
sedation without risk of respiratory depression and can provide cooperative or semi arousable sedation.
The mechanism by which a2 adrenergic receptor agonists produce analgesia is likely to be multifactorial.
Peripherally a2 adrenergic agonists produce analgesia by reducing the release of norepinephrine and
a2 receptor independent inhibitory effect on nerve fibre action potential.
Recent pre-clinical and clinical studies show that the glucocorticoid dexamethasone appears to be
effective as adjuvant to local anesthetics since it posses anti-inflammatory and analgesic properties. In
addition, perineural injection of steroid does influence post operative analgesia. This study was done to
compare the adjuvant effect of dexamethasone and dexmedetomidine, when aded with local anesthetics in
Supraclavicular brachial plexus block.
Materials and Methods: It was a prospective randomized control trial conducted for 18 months in LLR
hospital Kanpur. 90 patients of ASA grade 1 and 2 aged more than 18 yrs of either sex were included and
Thirty patients were randomly divided in each of the three groups and observations were made regarding
hemodynamic changes such as HR, MAP, SPO2 and onset of sensory, motor block and duration of motor,
sensory effect. Student t test and analysis of variance were the methods used for analysis.
Result: Additions of injection dexamethasone and injection dexmedetomidine with lignocaine markedly
prolonged duration of sensory and motor block however duration of injection dexmedetomidine was found
to be longer as compared to dexamethasone.
Conclusion: Dexmedetomidine has longer duration of motor and sensory effect when used as an adjuvent
as compared to dexamethasone.
Keyword :
Dexmedetomidine, Dexamethasone, Brachial plexus block.