Effects of Intramuscular Dexmedetomidine Versus Clonidine on the Duration of Subarachnoid Block and Analgesia for Lower Limb Orthopedic Surgeries

Background: Alpha-2adrenergic agonists, when used simultaneously as systemic adjuvants to local anesthetics show synergisticaction and improve the quality of spinal anesthesia and prolong the post-operative analgesia. We aimed to study the effects ofintramuscular dexmedetomidine versus clonidine on the duration of bupivacaine sub-arachnoid block, post-operative analgesia,and sedation in patients undergoing lower limb orthopedic surgeries.Materials and Methods: The study design was a prospective, randomized, and double-blind study. Eighty adult consentedpatients of ASA I or II, scheduled for orthopedic lower limb surgeries under spinal block were randomized to two groups of40 patients per group. Group D received IM dexmedetomidine 1 μgkg−1, Group C received IM clonidine 2 μgkg−1, and 30 minbefore the bupivacaine subarachnoid block. The time of onset of sensory and motor block, the time required for completesensory and motor recovery, time of the first request of rescue analgesia, and sedation levels were compared between thegroups. Collected data were analyzed using the student “t” test, Chi-square test/Fisher exact test, and P < 0.05 was consideredstatistically significant.Results: The mean onset time of sensory and motor block was reduced, the mean time required for complete sensory recoverywas increased and the time of the first request of rescue analgesia was prolonged in the dexmedetomidine group comparedto clonidine group with a significant P < 0.05. Ramsay sedation score was higher in the dexmedetomidine group compared toclonidine group (P = 0.003)Conclusion: Premedication with a single dose of intramuscular dexmedetomidine before bupivacaine spinal anesthesia actsas an effective adjuvant and potentiates the quality of block and prolongs post-operative analgesia more than intramuscularclonidine.

Efficacy of Potassium Chloride 0.2 mmol as Adjuvant to 0.5% Ropivacaine versus Plain Ropivacaine 0.5% in Supraclavicular Brachial Plexus Block

Background: Brachial plexus block is one of the most common regional anesthetic techniques used for upper limb surgeries.Various adjuvants have been tried for prolonging the duration of post-operative analgesia and also to enhance the quality ofblock. We aimed to study the effects of the addition of potassium chloride to ropivacaine in supraclavicular brachial plexusblock compared to plain ropivacaine.Materials and Methods: This prospective, randomized, double-blind, and controlled study includes 80 adult patients agedbetween 20 and 60 years with ASA Grade I and II scheduled for upper limb surgeries. These patients were randomly allocatedinto two groups of 40 each. The patients in the group I/non-KCL group received 30 ml of 0.5 % ropivacaine along with 1 mlnormal saline (control group). Group II/KCL group received 30 ml of 0.5% ropivacaine along with 0.2 mmol (0.1 ml) of potassiumchloride (prepared by adding 0.1 ml of potassium chloride diluted with normal saline to make a volume of 1 ml) (study group).The onset, duration of sensory and motor blockade, quality of sensory and motor blockade, and the duration of post-operativeanalgesia were compared between both the groups.Results: The onset of sensory and motor blockade was earlier in Group II/ study group when compared to plain ropivacainegroup/Group I and was statistically significant with a P < 0.05. The mean duration of sensory and motor blockade was prolongedin Group II with enhanced quality of analgesia compared to Group I.Conclusion: In our study, it concludes that the addition of potassium chloride as an adjuvant to ropivacaine had a significantclinical advantage over plain ropivacaine on the onset, duration, quality of sensory and motor blockade, and post-operativeanalgesia in supraclavicular brachial plexus block.