ORIGINAL ARTICLE
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Effect of dexmedetomidine as adjuvant in ropivacaine-induced supraclavicular brachial plexus block: A prospective, double-blinded and randomized controlled study Anjan Das, Saikat Majumdar1, Susanta Halder2, Surajit Chattopadhyay3, Saswati Pal1, Ratul Kundu4, Subrata Kumar Mandal, Sandip Chattopadhyay5
A B S T R A C T
Departments of Anaesthesiology, and 5G & O, College of Medicine & Sagore Dutta Hospital, Departments of Anaesthesiology, 1 NRS Medical College, 2R. G. Kar Medical College, 4Institute of Post Graduate Medical Education And Research, Kolkata, 3Bankura Sammilani Medical College, Bankura, West Bengal, India Address for correspondence: Dr. Anjan Das, 174, Gorakshabashi Road, Royal Plaza Apartment, 4th Floor, Flat No. 1, Nager Bazar, Kolkata - 700 028, West Bengal, India. E-mail: [email protected]
Background and Aims: Different additives have been used to prolong brachial plexus block. We evaluated the effect of adding dexmedetomidine to ropivacaine for supraclavicular brachial plexus blockade. The primary endpoints were the onset and duration of sensory and motor block and duration of analgesia. Materials and Methods: A total of 84 patients (20-50 years) posted for elective forearm and hand surgery under supraclavicular brachial plexus block were divided into two equal groups (Group R and RD) in a randomized, double-blind fashion. In group RD (n = 42) 30 ml 0.5% ropivacaine +1 ml (100 µg) of dexmedetomidine and group R (n = 42) 30 ml 0.5% ropivacaine +1 ml normal saline were administered in supraclavicular block. Sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, postoperative visual analog scale (VAS), hemodynamics and sideeffects were recorded for each patient. Results: Though with similar demographic profile in both groups, sensory and motor block in group RD (P < 0.05) was earlier than group R. Sensory and motor block duration and time to first analgesic use were significantly longer and the total need for rescue analgesics was lower in group RD (P 0.05). Whereas, Table 4 shows that sensory and motor block durations are significantly greater in the group receiving dexmedetomidine (RD) (P < 0.05) than group R. The mean time from block placement to first request for pain medication, i.e., the duration of analgesia was 846.67 min in the dexmedetomidine group, but 544.07 min in the normal saline group. This difference (about 302.6 min) was highly significant (P < 0.001) statistically as well as clinically [Table 4 and Figure 1]. Table 5 and Figure 2 shows that group RD required less number of diclofenac sodium injection as rescue analgesics than patients in group R (control group) in first 24 h of post-operative period, and the difference is statistically highly significant (P < 0.01). Vol. 8 (Supplement 1), November 2014
Table 1: Comparison of demographic data between the two study groups Parameter
Age (years) Bodyweight (kg) Sex (male/female) (%) Height (cm) ASA physical status (I/II) (%) Surgery time (min) Tourniquet time (min)
Group RD (n = 40) ropivacaine + dexmedetomidine 43.95±10.62 51.87±5.32 8 (20):32 (80) 153.4±4.29 30 (75)/10 (25)
Group R (n = 40) ropivacaine + normal saline 44±10.55 51.07±5.76 7 (17.5):33 (82.5) 154.9±4.33 28 (70)/12 (30)
P value
80.56±19.54 94.28±19.74
78.72±22.98 92.24±24.94
0.74 0.72
0.98 0.58 0.77 0.34 0.62
ASA: American society of anesthesiologists
Table 2: Indications of upper limb orthopedic surgery for two groups Indications for upper limb surgery Professional accidental hand injury Fracture both bone forearm IM locked nailing for diaphyseal forearm fractures Percutaneous K wire fixation in Colle’s fracture Radial head fractures Fracture distal humerus Monteggia fracture-dislocation Galeazzi fractures
Group RD (%) 9 (22.5) 8 (20) 5 (12.5)
Group R (%) 10 (25) 6 (15) 7 (17.5)
7 (17.5)
6 (15)
1 (2.5) 5 (12.5) 3 (7.5) 2 (5)
3 (7.5) 3 (7.5) 2 (5) 3 (7.5)
Data are n (%); IM: Intramuscular
Table 3: Onset time for sensory and motor block Parameters Time taken to achieve sensory blockade (min) Time taken to achieve motor blockade (min)
Group RD (n = 40) 14.71±3.70
Group R (n = 40) 15.17±5.09
P value 0.70
19.96±1.28
20.26±1.28
0.40
Table 4: Duration of sensory and motor block Parameters Duration of sensory blockade (min) Duration of motor blockade (min)
Group RD (n = 40) 846.67±102.09
Group R (n = 40) 544.07±55.40
P value 0.000
624.2±200.9
516.8±155.85
0.015
Table 5: Rescue analgesic requirement in post-operative period (no. of IM diclofenac sodium injections) Groups
Group RD (n=40) Group R (n=40)
No. of diclofenac required in first 24 h of post-operative period 1 (once 2 (twice 3 (thrice injection) injection) injection) 9 2 0 5 13 7
P value
0.01
IM: Intramuscular
Saudi Journal of Anesthesia
Das, et al.: Dexmedetomidine adjuvant in supraclavicular brachial plexus block
Figure 3 shows that VAS score was of much higher value in group R than RD group. Again group RD suffered from bradycardia, [Table 6] which was statistically higher (P < 0.05) than group R. Other side-effects were quiet comparable (P > 0.05) among two groups. DISCUSSION Supraclavicular blocks are performed at the level of the brachial plexus trunks. Here, almost the entire sensory, motor and sympathetic innervations of the upper extremity are carried in just three nerve structures (trunks), confined to a very small surface area. Consequently, typical features of this block include rapid onset, predictable and dense anesthesia along with its high success rate.[13] Local anesthetics alone for supraclavicular brachial plexus block provide good operative conditions but have a shorter duration of postoperative analgesia. Hence various drugs such as opioids,[3] clonidine,[4] neostigmine, dexamethasone,[5] midazolam,[6] magnesium[14] etc., were used as adjuvant with local anesthetics in brachial plexus block to achieve quick, dense and prolonged block, but the results are either inconclusive or associated with side-effects.
in a total of 100 patients yielded similar results.[17] The mean duration of surgery and tourniquet time were almost comparable in both groups with no significant statistical difference [Table 1]. From Table 2, it is quite evident that indications of surgical procedures were almost similar in both groups and had no statistical significance. The onset time of sensory block
Figure 1: Duration of sensory and motor block
Dexmedetomidine; a highly selective, α2-adrenergic agonist; has analgesic, sedative, anesthetic sparing effects when used in systemic route.[8] Use of dexmedetomidine as an adjuvant mixed with local anesthetics has been performed with neuraxial anesthesia in both adult and pediatric patients.[15,16] Mixing dexmedetomidine as adjuvant with local anesthetics during peripheral nerve and nerve plexus blockade has recently been practiced by anesthesiologists.[11,12] In this prospective, randomized, and double-blinded trial, we had compared the effect of 1 ml of dexmedetomidine and placebo as an adjuvant to 30 ml 0.50% ropivacaine in supraclavicular brachial plexus block, on the onset time and duration of sensory and motor block as well as on the post-operative rescue analgesic (injection diclofenac sodium) requirement.
Figure 2: Number of intramuscular diclofenac injection as rescue analgesic in first 24 h post-operative period
The demographic profile, between two groups, which was statistically insignificant (P > 0.05) of our patients was quite similar with other research investigations and provided us the uniform platform to evenly compare the results obtained. A study on the role of dexmedetomidine for post-operative analgesia was conducted by Gupta et al. Table 6: Comparison of side effects Parameters Pneumothorax Horner syndrome Bradycardia
Group D (n = 42) 2 5 4
Saudi Journal of Anesthesia
Group RD (n = 42) 4 2 0
P value 0.39 0.12 0.04
Figure 3: Comparison of visual analog scale score among groups RD and group R
Vol. 8 (Supplement 1), November 2014
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Das, et al.: Dexmedetomidine adjuvant in supraclavicular brachial plexus block Page | S76
(14.71 ± 3.70 min in RD group vs. 15.17 ± 5.09 min in R group) was similar in the two groups (P = 0.70) [Table 3]. These findings correlate with the studies of Rancourt et al.[18] However Ammar and Mahmoud,[10] Kaygusuz et al.[19] in their studies, found significantly earlier onset of sensory block in the RD group than in the group R. The onset time of motor block (19.96 ± 1.28 min in RD group vs. 20.26 ± 1.28 min in group R) was also similar in the two groups (P = 0.40). On the contrary, Ammar and Mahmoud,[10] Gandhi et al.[20] in their study found that motor block onset was hastened by the use of dexmedetomidine adjuvant in brachial plexus block with bupivacaine. Again in a study conducted by Marhofer et al.[21] in 36 volunteers it has been found that dexmedetomidine as adjuvant though produced early onset of motor block, sensory block was not different from the control group or i.v group. In our study, the duration of sensory block (846.67 ± 102.09 min in group RD vs. 544.07 ± 55.40 min in group R) was significantly longer in the dexmedetomidine group than in the control group (P < 0.001). The duration of motor block (624.2 ± 200.9 min in RD group vs. 516.8 ± 155.85 min in R group) was also significantly longer in the dexmedetomidine group than in the control group (P 0.05). Esmaoglu et al.[11] also found significant bradycardia in dexmedetomidine plus levobupivacaine group than levobupivacaine alone. However, they found significant hypotension with dexmedetomidine group, which was absent in our study. Ropivacaine and Dexmedetomidine dose was chosen as per recommendation in the text book as well as experience of our previous researchers.[10,22-24] While writing this discussion we have found the reference of lowest possible volume (10 ml) and concentration (0.375%) of ropivacaine for post-operative analgesia by Iwata et al.[25] However, we had used a higher concentration and much higher volume for intra-as well as post-operative analgesia. Several hypothesized mechanisms of action have been suggested to explain the analgesic effect of dexmedetomidine. Some of these include vasoconstriction around the injection site,[26] direct suppression of impulse propagation through neurons as a result of a complex interaction with axonal ion channels or receptors,[27] local release of enkephalin-like substances,[28] a decrease in localized proinflammatory mediators[29] and an increase in anti-inflammatory cytokines through an α2-adrenoceptormediated mechanism.[30] Finally, unsuccessful block was encountered in two patients (5%) in each group in our study, which is quite comparable to previous studies using nerve stimulator guided approaches to supraclavicular brachial plexus blockade.[31] We do conclude that addition of 100 mcg dexmedetomidine to ropivacaine 0.50% solution in supraclavicular brachial plexus block prolongs the duration of sensory and motor blockade reduces the requirement of rescue analgesic in the post-operative period, but has no appreciable effect on the onset time of sensory and motor blockade. REFERENCES 1. Bruce BG, Green A, Blaine TA, Wesner LV. Brachial plexus blocks for upper extremity orthopaedic surgery. J Am Acad Orthop Surg 2012;20:38-47. 2. Vainionpää VA, Haavisto ET, Huha TM, Korpi KJ, Nuutinen LS, Hollmén AI, et al. A clinical and pharmacokinetic comparison
Saudi Journal of Anesthesia
Das, et al.: Dexmedetomidine adjuvant in supraclavicular brachial plexus block of ropivacaine and bupivacaine in axillary plexus block. Anesth Analg 1995;81:534-8. 3. Bazin JE, Massoni C, Groslier D, Fenies V, Bittar M, Schoeffler P. Brachial plexus block: Effect of the addition of sufentanil to local anesthetic mixture on postoperative analgesia duration. Ann Fr Anesth Reanim 1997;16:9-13. 4. Kohli S, Kaur M, Sahoo S, Vajifdar H, Kohli P. Brachial plexus block: Comparison of two different doses of clonidine added to bupivacaine. J Anaesthesiol Clin Pharmacol 2013;29:491-5. 5. Yadav RK, Sah BP, Kumar P, Singh SN. Effectiveness of addition of neostigmine or dexamethasone to local anaesthetic in providing perioperative analgesia for brachial plexus block: A prospective, randomized, double blinded, controlled study. Kathmandu Univ Med J (KUMJ) 2008;6:302-9. 6. Jarbo K, Batra YK, Panda NB. Brachial plexus block with midazolam and bupivacaine improves analgesia. Can J Anaesth 2005;52:822-6. 7. Gerlach AT, Dasta JF. Dexmedetomidine: An updated review. Ann Pharmacother 2007;41:245-52. 8. Huang R, Hertz L. Receptor subtype and dose dependence of dexmedetomidine-induced accumulation of [14C] glutamine in astrocytes suggests glial involvement in its hypnotic-sedative and anesthetic-sparing effects. Brain Res 2000;873:297-301. 9. Kettner SC. Dexmedetomidine as adjuvant for peripheral nerve blocks. Br J Anaesth 2013;111:123. 10. Ammar AS, Mahmoud KM. Ultrasound-guided single injection infraclavicular brachial plexus block using bupivacaine alone or combined with dexmedetomidine for pain control in upper limb surgery: A prospective randomized controlled trial. Saudi J Anaesth 2012;6:109-14. 11. Esmaoglu A, Yegenoglu F, Akin A, Turk CY. Dexmedetomidine added to levobupivacaine prolongs axillary brachial plexus block. Anesth Analg 2010;111:1548-51. 12. Obayah GM, Refaie A, Aboushanab O, Ibraheem N, Abdelazees M. Addition of dexmedetomidine to bupivacaine for greater palatine nerve block prolongs postoperative analgesia after cleft palate repair. Eur J Anaesthesiol 2010;27:280-4. 13. Singh S, Aggarwal A. A randomized controlled doubleblinded prospective study of the efficacy of clonidine added to bupivacaine as compared with bupivacaine alone used in supraclavicular brachial plexus block for upper limb surgeries. Indian J Anaesth 2010;54:552-7. 14. Dogru K, Yildirim D, Ulgey A, Aksu R, Bicer C, Boyaci A. Adding magnesium to levobupivacaine for axillary brachial plexus block in arteriovenous fistule surgery. Bratisl Lek Listy 2012;113:607-9. 15. Al-Ghanem SM, Massad IM, Al-Mustafa MM, Al-Zaben KR, Qudaisat IY, Qatawneh AM, et al. Effect of adding dexmedetomidine versus fentanyl to intrathecal bupivacaine on spinal block characteristics in gynaecological procedures: A double blind controlled study. Am J Appl Sci 2009;6:882-7. 16. El-Hennawy AM, Abd-Elwahab AM, Abd-Elmaksoud AM, El-Ozairy HS, Boulis SR. Addition of clonidine or dexmedetomidine to bupivacaine prolongs caudal analgesia in children. Br J Anaesth 2009;103:268-74. 17. Gupta R, Bogra J, Verma R, Kohli M, Kushwaha JK, Kumar S. Dexmedetomidine as an intrathecal adjuvant for postoperative analgesia. Indian J Anaesth 2011;55:347-51. 18. Rancourt MP, Albert NT, Côté M, Létourneau DR, Bernard PM.
Saudi Journal of Anesthesia
Posterior tibial nerve sensory blockade duration prolonged by adding dexmedetomidine to ropivacaine. Anesth Analg 2012;115:958-62. 19. Kaygusuz K, Ozdemir I, Duger C, Gursoy S, Ozturk H, Kayacan U, et al. Effects of adding dexmedetomidine to levobupivacaine in axillary brachial plexus block. Curr Ther Res 2012;73:103-11. 20. Gandhi R, Shah A, Patel I. Use of dexmedetomidine along with bupivacaine for brachial plexus block. Natl J Med Res 2012;2:67-9. 21. Marhofer D, Kettner SC, Marhofer P, Pils S, Weber M, Zeitlinger M. Dexmedetomidine as an adjuvant to ropivacaine prolongs peripheral nerve block: A volunteer study. Br J Anaesth 2013;110:438-42. 22. Berde CB, Strichartz GR. Local anesthetics. In: Miller RD, Eriksson LI, Fleisher LA, Wiener-Kronish JP, Young WL, editors. Miller’s Anesthesia. 7th ed. Philadelphia: Churchill Livingstone Elsevier; 2010. p. 913-36. 23. Duggan E, El Beheiry H, Perlas A, Lupu M, Nuica A, Chan VW, et al. Minimum effective volume of local anesthetic for ultrasound-guided supraclavicular brachial plexus block. Reg Anesth Pain Med 2009;34:215-8. 24. Yang CW, Kwon HU, Cho CK, Jung SM, Kang PS, Park ES, et al. A comparison of infraclavicular and supraclavicular approaches to the brachial plexus using neurostimulation. Korean J Anesthesiol 2010;58:260-6. 25. Iwata T, Nakahashi K, Inoue S, Furuya H. Low-dose ropivacaine for supraclavicular brachial plexus block combined with general anesthesia for successful postoperative analgesia: A case series. Saudi J Anaesth 2013;7:37-9. 26. Yoshitomi T, Kohjitani A, Maeda S, Higuchi H, Shimada M, Miyawaki T. Dexmedetomidine enhances the local anesthetic action of lidocaine via an alpha-2A adrenoceptor. Anesth Analg 2008;107:96-101. 27. Kosugi T, Mizuta K, Fujita T, Nakashima M, Kumamoto E. High concentrations of dexmedetomidine inhibit compound action potentials in frog sciatic nerves without alpha(2) adrenoceptor activation. Br J Pharmacol 2010;160:1662-76. 28. Fürst S. Transmitters involved in antinociception in the spinal cord. Brain Res Bull 1999;48:129-41. 29. Kawasaki T, Kawasaki C, Ueki M, Hamada K, Habe K, Sata T. Dexmedetomidine suppresses proinflammatory mediator production in human whole blood in vitro. J Trauma Acute Care Surg 2013;74:1370-5. 30. Xu L, Bao H, Si Y, Wang X. Effects of dexmedetomidine on early and late cytokines during polymicrobial sepsis in mice. Inflamm Res 2013;62:507-14. 31. Franco CD, Vieira ZE. 1,001 subclavian perivascular brachial plexus blocks: Success with a nerve stimulator. Reg Anesth Pain Med 2000;25:41-6. How to cite this article: Das A, Majumdar S, Halder S, Chattopadhyay S, Pal S, Kundu R, et al. Effect of dexmedetomidine as adjuvant in ropivacaine-induced supraclavicular brachial plexus block: A prospective, double-blinded and randomized controlled study. Saudi J Anaesth 2014;8:72-7. Source of Support: Nil, Conflict of Interest: None declared.
Vol. 8 (Supplement 1), November 2014
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Effect of dexmedetomidine as adjuvant in ropivacaine-induced supraclavicular brachial plexus block: A prospective, double-blinded and randomized controlled study Anjan Das, Saikat Majumdar1, Susanta Halder2, Surajit Chattopadhyay3, Saswati Pal1, Ratul Kundu4, Subrata Kumar Mandal, Sandip Chattopadhyay5
A B S T R A C T
Departments of Anaesthesiology, and 5G & O, College of Medicine & Sagore Dutta Hospital, Departments of Anaesthesiology, 1 NRS Medical College, 2R. G. Kar Medical College, 4Institute of Post Graduate Medical Education And Research, Kolkata, 3Bankura Sammilani Medical College, Bankura, West Bengal, India Address for correspondence: Dr. Anjan Das, 174, Gorakshabashi Road, Royal Plaza Apartment, 4th Floor, Flat No. 1, Nager Bazar, Kolkata - 700 028, West Bengal, India. E-mail: [email protected]
Background and Aims: Different additives have been used to prolong brachial plexus block. We evaluated the effect of adding dexmedetomidine to ropivacaine for supraclavicular brachial plexus blockade. The primary endpoints were the onset and duration of sensory and motor block and duration of analgesia. Materials and Methods: A total of 84 patients (20-50 years) posted for elective forearm and hand surgery under supraclavicular brachial plexus block were divided into two equal groups (Group R and RD) in a randomized, double-blind fashion. In group RD (n = 42) 30 ml 0.5% ropivacaine +1 ml (100 µg) of dexmedetomidine and group R (n = 42) 30 ml 0.5% ropivacaine +1 ml normal saline were administered in supraclavicular block. Sensory and motor block onset times and block durations, time to first analgesic use, total analgesic need, postoperative visual analog scale (VAS), hemodynamics and sideeffects were recorded for each patient. Results: Though with similar demographic profile in both groups, sensory and motor block in group RD (P < 0.05) was earlier than group R. Sensory and motor block duration and time to first analgesic use were significantly longer and the total need for rescue analgesics was lower in group RD (P 0.05). Whereas, Table 4 shows that sensory and motor block durations are significantly greater in the group receiving dexmedetomidine (RD) (P < 0.05) than group R. The mean time from block placement to first request for pain medication, i.e., the duration of analgesia was 846.67 min in the dexmedetomidine group, but 544.07 min in the normal saline group. This difference (about 302.6 min) was highly significant (P < 0.001) statistically as well as clinically [Table 4 and Figure 1]. Table 5 and Figure 2 shows that group RD required less number of diclofenac sodium injection as rescue analgesics than patients in group R (control group) in first 24 h of post-operative period, and the difference is statistically highly significant (P < 0.01). Vol. 8 (Supplement 1), November 2014
Table 1: Comparison of demographic data between the two study groups Parameter
Age (years) Bodyweight (kg) Sex (male/female) (%) Height (cm) ASA physical status (I/II) (%) Surgery time (min) Tourniquet time (min)
Group RD (n = 40) ropivacaine + dexmedetomidine 43.95±10.62 51.87±5.32 8 (20):32 (80) 153.4±4.29 30 (75)/10 (25)
Group R (n = 40) ropivacaine + normal saline 44±10.55 51.07±5.76 7 (17.5):33 (82.5) 154.9±4.33 28 (70)/12 (30)
P value
80.56±19.54 94.28±19.74
78.72±22.98 92.24±24.94
0.74 0.72
0.98 0.58 0.77 0.34 0.62
ASA: American society of anesthesiologists
Table 2: Indications of upper limb orthopedic surgery for two groups Indications for upper limb surgery Professional accidental hand injury Fracture both bone forearm IM locked nailing for diaphyseal forearm fractures Percutaneous K wire fixation in Colle’s fracture Radial head fractures Fracture distal humerus Monteggia fracture-dislocation Galeazzi fractures
Group RD (%) 9 (22.5) 8 (20) 5 (12.5)
Group R (%) 10 (25) 6 (15) 7 (17.5)
7 (17.5)
6 (15)
1 (2.5) 5 (12.5) 3 (7.5) 2 (5)
3 (7.5) 3 (7.5) 2 (5) 3 (7.5)
Data are n (%); IM: Intramuscular
Table 3: Onset time for sensory and motor block Parameters Time taken to achieve sensory blockade (min) Time taken to achieve motor blockade (min)
Group RD (n = 40) 14.71±3.70
Group R (n = 40) 15.17±5.09
P value 0.70
19.96±1.28
20.26±1.28
0.40
Table 4: Duration of sensory and motor block Parameters Duration of sensory blockade (min) Duration of motor blockade (min)
Group RD (n = 40) 846.67±102.09
Group R (n = 40) 544.07±55.40
P value 0.000
624.2±200.9
516.8±155.85
0.015
Table 5: Rescue analgesic requirement in post-operative period (no. of IM diclofenac sodium injections) Groups
Group RD (n=40) Group R (n=40)
No. of diclofenac required in first 24 h of post-operative period 1 (once 2 (twice 3 (thrice injection) injection) injection) 9 2 0 5 13 7
P value
0.01
IM: Intramuscular
Saudi Journal of Anesthesia
Das, et al.: Dexmedetomidine adjuvant in supraclavicular brachial plexus block
Figure 3 shows that VAS score was of much higher value in group R than RD group. Again group RD suffered from bradycardia, [Table 6] which was statistically higher (P < 0.05) than group R. Other side-effects were quiet comparable (P > 0.05) among two groups. DISCUSSION Supraclavicular blocks are performed at the level of the brachial plexus trunks. Here, almost the entire sensory, motor and sympathetic innervations of the upper extremity are carried in just three nerve structures (trunks), confined to a very small surface area. Consequently, typical features of this block include rapid onset, predictable and dense anesthesia along with its high success rate.[13] Local anesthetics alone for supraclavicular brachial plexus block provide good operative conditions but have a shorter duration of postoperative analgesia. Hence various drugs such as opioids,[3] clonidine,[4] neostigmine, dexamethasone,[5] midazolam,[6] magnesium[14] etc., were used as adjuvant with local anesthetics in brachial plexus block to achieve quick, dense and prolonged block, but the results are either inconclusive or associated with side-effects.
in a total of 100 patients yielded similar results.[17] The mean duration of surgery and tourniquet time were almost comparable in both groups with no significant statistical difference [Table 1]. From Table 2, it is quite evident that indications of surgical procedures were almost similar in both groups and had no statistical significance. The onset time of sensory block
Figure 1: Duration of sensory and motor block
Dexmedetomidine; a highly selective, α2-adrenergic agonist; has analgesic, sedative, anesthetic sparing effects when used in systemic route.[8] Use of dexmedetomidine as an adjuvant mixed with local anesthetics has been performed with neuraxial anesthesia in both adult and pediatric patients.[15,16] Mixing dexmedetomidine as adjuvant with local anesthetics during peripheral nerve and nerve plexus blockade has recently been practiced by anesthesiologists.[11,12] In this prospective, randomized, and double-blinded trial, we had compared the effect of 1 ml of dexmedetomidine and placebo as an adjuvant to 30 ml 0.50% ropivacaine in supraclavicular brachial plexus block, on the onset time and duration of sensory and motor block as well as on the post-operative rescue analgesic (injection diclofenac sodium) requirement.
Figure 2: Number of intramuscular diclofenac injection as rescue analgesic in first 24 h post-operative period
The demographic profile, between two groups, which was statistically insignificant (P > 0.05) of our patients was quite similar with other research investigations and provided us the uniform platform to evenly compare the results obtained. A study on the role of dexmedetomidine for post-operative analgesia was conducted by Gupta et al. Table 6: Comparison of side effects Parameters Pneumothorax Horner syndrome Bradycardia
Group D (n = 42) 2 5 4
Saudi Journal of Anesthesia
Group RD (n = 42) 4 2 0
P value 0.39 0.12 0.04
Figure 3: Comparison of visual analog scale score among groups RD and group R
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Das, et al.: Dexmedetomidine adjuvant in supraclavicular brachial plexus block Page | S76
(14.71 ± 3.70 min in RD group vs. 15.17 ± 5.09 min in R group) was similar in the two groups (P = 0.70) [Table 3]. These findings correlate with the studies of Rancourt et al.[18] However Ammar and Mahmoud,[10] Kaygusuz et al.[19] in their studies, found significantly earlier onset of sensory block in the RD group than in the group R. The onset time of motor block (19.96 ± 1.28 min in RD group vs. 20.26 ± 1.28 min in group R) was also similar in the two groups (P = 0.40). On the contrary, Ammar and Mahmoud,[10] Gandhi et al.[20] in their study found that motor block onset was hastened by the use of dexmedetomidine adjuvant in brachial plexus block with bupivacaine. Again in a study conducted by Marhofer et al.[21] in 36 volunteers it has been found that dexmedetomidine as adjuvant though produced early onset of motor block, sensory block was not different from the control group or i.v group. In our study, the duration of sensory block (846.67 ± 102.09 min in group RD vs. 544.07 ± 55.40 min in group R) was significantly longer in the dexmedetomidine group than in the control group (P < 0.001). The duration of motor block (624.2 ± 200.9 min in RD group vs. 516.8 ± 155.85 min in R group) was also significantly longer in the dexmedetomidine group than in the control group (P 0.05). Esmaoglu et al.[11] also found significant bradycardia in dexmedetomidine plus levobupivacaine group than levobupivacaine alone. However, they found significant hypotension with dexmedetomidine group, which was absent in our study. Ropivacaine and Dexmedetomidine dose was chosen as per recommendation in the text book as well as experience of our previous researchers.[10,22-24] While writing this discussion we have found the reference of lowest possible volume (10 ml) and concentration (0.375%) of ropivacaine for post-operative analgesia by Iwata et al.[25] However, we had used a higher concentration and much higher volume for intra-as well as post-operative analgesia. Several hypothesized mechanisms of action have been suggested to explain the analgesic effect of dexmedetomidine. Some of these include vasoconstriction around the injection site,[26] direct suppression of impulse propagation through neurons as a result of a complex interaction with axonal ion channels or receptors,[27] local release of enkephalin-like substances,[28] a decrease in localized proinflammatory mediators[29] and an increase in anti-inflammatory cytokines through an α2-adrenoceptormediated mechanism.[30] Finally, unsuccessful block was encountered in two patients (5%) in each group in our study, which is quite comparable to previous studies using nerve stimulator guided approaches to supraclavicular brachial plexus blockade.[31] We do conclude that addition of 100 mcg dexmedetomidine to ropivacaine 0.50% solution in supraclavicular brachial plexus block prolongs the duration of sensory and motor blockade reduces the requirement of rescue analgesic in the post-operative period, but has no appreciable effect on the onset time of sensory and motor blockade. REFERENCES 1. Bruce BG, Green A, Blaine TA, Wesner LV. Brachial plexus blocks for upper extremity orthopaedic surgery. J Am Acad Orthop Surg 2012;20:38-47. 2. Vainionpää VA, Haavisto ET, Huha TM, Korpi KJ, Nuutinen LS, Hollmén AI, et al. A clinical and pharmacokinetic comparison
Saudi Journal of Anesthesia
Das, et al.: Dexmedetomidine adjuvant in supraclavicular brachial plexus block of ropivacaine and bupivacaine in axillary plexus block. Anesth Analg 1995;81:534-8. 3. Bazin JE, Massoni C, Groslier D, Fenies V, Bittar M, Schoeffler P. Brachial plexus block: Effect of the addition of sufentanil to local anesthetic mixture on postoperative analgesia duration. Ann Fr Anesth Reanim 1997;16:9-13. 4. Kohli S, Kaur M, Sahoo S, Vajifdar H, Kohli P. Brachial plexus block: Comparison of two different doses of clonidine added to bupivacaine. J Anaesthesiol Clin Pharmacol 2013;29:491-5. 5. Yadav RK, Sah BP, Kumar P, Singh SN. Effectiveness of addition of neostigmine or dexamethasone to local anaesthetic in providing perioperative analgesia for brachial plexus block: A prospective, randomized, double blinded, controlled study. Kathmandu Univ Med J (KUMJ) 2008;6:302-9. 6. Jarbo K, Batra YK, Panda NB. Brachial plexus block with midazolam and bupivacaine improves analgesia. Can J Anaesth 2005;52:822-6. 7. Gerlach AT, Dasta JF. Dexmedetomidine: An updated review. Ann Pharmacother 2007;41:245-52. 8. Huang R, Hertz L. Receptor subtype and dose dependence of dexmedetomidine-induced accumulation of [14C] glutamine in astrocytes suggests glial involvement in its hypnotic-sedative and anesthetic-sparing effects. Brain Res 2000;873:297-301. 9. Kettner SC. Dexmedetomidine as adjuvant for peripheral nerve blocks. Br J Anaesth 2013;111:123. 10. Ammar AS, Mahmoud KM. Ultrasound-guided single injection infraclavicular brachial plexus block using bupivacaine alone or combined with dexmedetomidine for pain control in upper limb surgery: A prospective randomized controlled trial. Saudi J Anaesth 2012;6:109-14. 11. Esmaoglu A, Yegenoglu F, Akin A, Turk CY. Dexmedetomidine added to levobupivacaine prolongs axillary brachial plexus block. Anesth Analg 2010;111:1548-51. 12. Obayah GM, Refaie A, Aboushanab O, Ibraheem N, Abdelazees M. Addition of dexmedetomidine to bupivacaine for greater palatine nerve block prolongs postoperative analgesia after cleft palate repair. Eur J Anaesthesiol 2010;27:280-4. 13. Singh S, Aggarwal A. A randomized controlled doubleblinded prospective study of the efficacy of clonidine added to bupivacaine as compared with bupivacaine alone used in supraclavicular brachial plexus block for upper limb surgeries. Indian J Anaesth 2010;54:552-7. 14. Dogru K, Yildirim D, Ulgey A, Aksu R, Bicer C, Boyaci A. Adding magnesium to levobupivacaine for axillary brachial plexus block in arteriovenous fistule surgery. Bratisl Lek Listy 2012;113:607-9. 15. Al-Ghanem SM, Massad IM, Al-Mustafa MM, Al-Zaben KR, Qudaisat IY, Qatawneh AM, et al. Effect of adding dexmedetomidine versus fentanyl to intrathecal bupivacaine on spinal block characteristics in gynaecological procedures: A double blind controlled study. Am J Appl Sci 2009;6:882-7. 16. El-Hennawy AM, Abd-Elwahab AM, Abd-Elmaksoud AM, El-Ozairy HS, Boulis SR. Addition of clonidine or dexmedetomidine to bupivacaine prolongs caudal analgesia in children. Br J Anaesth 2009;103:268-74. 17. Gupta R, Bogra J, Verma R, Kohli M, Kushwaha JK, Kumar S. Dexmedetomidine as an intrathecal adjuvant for postoperative analgesia. Indian J Anaesth 2011;55:347-51. 18. Rancourt MP, Albert NT, Côté M, Létourneau DR, Bernard PM.
Saudi Journal of Anesthesia
Posterior tibial nerve sensory blockade duration prolonged by adding dexmedetomidine to ropivacaine. Anesth Analg 2012;115:958-62. 19. Kaygusuz K, Ozdemir I, Duger C, Gursoy S, Ozturk H, Kayacan U, et al. Effects of adding dexmedetomidine to levobupivacaine in axillary brachial plexus block. Curr Ther Res 2012;73:103-11. 20. Gandhi R, Shah A, Patel I. Use of dexmedetomidine along with bupivacaine for brachial plexus block. Natl J Med Res 2012;2:67-9. 21. Marhofer D, Kettner SC, Marhofer P, Pils S, Weber M, Zeitlinger M. Dexmedetomidine as an adjuvant to ropivacaine prolongs peripheral nerve block: A volunteer study. Br J Anaesth 2013;110:438-42. 22. Berde CB, Strichartz GR. Local anesthetics. In: Miller RD, Eriksson LI, Fleisher LA, Wiener-Kronish JP, Young WL, editors. Miller’s Anesthesia. 7th ed. Philadelphia: Churchill Livingstone Elsevier; 2010. p. 913-36. 23. Duggan E, El Beheiry H, Perlas A, Lupu M, Nuica A, Chan VW, et al. Minimum effective volume of local anesthetic for ultrasound-guided supraclavicular brachial plexus block. Reg Anesth Pain Med 2009;34:215-8. 24. Yang CW, Kwon HU, Cho CK, Jung SM, Kang PS, Park ES, et al. A comparison of infraclavicular and supraclavicular approaches to the brachial plexus using neurostimulation. Korean J Anesthesiol 2010;58:260-6. 25. Iwata T, Nakahashi K, Inoue S, Furuya H. Low-dose ropivacaine for supraclavicular brachial plexus block combined with general anesthesia for successful postoperative analgesia: A case series. Saudi J Anaesth 2013;7:37-9. 26. Yoshitomi T, Kohjitani A, Maeda S, Higuchi H, Shimada M, Miyawaki T. Dexmedetomidine enhances the local anesthetic action of lidocaine via an alpha-2A adrenoceptor. Anesth Analg 2008;107:96-101. 27. Kosugi T, Mizuta K, Fujita T, Nakashima M, Kumamoto E. High concentrations of dexmedetomidine inhibit compound action potentials in frog sciatic nerves without alpha(2) adrenoceptor activation. Br J Pharmacol 2010;160:1662-76. 28. Fürst S. Transmitters involved in antinociception in the spinal cord. Brain Res Bull 1999;48:129-41. 29. Kawasaki T, Kawasaki C, Ueki M, Hamada K, Habe K, Sata T. Dexmedetomidine suppresses proinflammatory mediator production in human whole blood in vitro. J Trauma Acute Care Surg 2013;74:1370-5. 30. Xu L, Bao H, Si Y, Wang X. Effects of dexmedetomidine on early and late cytokines during polymicrobial sepsis in mice. Inflamm Res 2013;62:507-14. 31. Franco CD, Vieira ZE. 1,001 subclavian perivascular brachial plexus blocks: Success with a nerve stimulator. Reg Anesth Pain Med 2000;25:41-6. How to cite this article: Das A, Majumdar S, Halder S, Chattopadhyay S, Pal S, Kundu R, et al. Effect of dexmedetomidine as adjuvant in ropivacaine-induced supraclavicular brachial plexus block: A prospective, double-blinded and randomized controlled study. Saudi J Anaesth 2014;8:72-7. Source of Support: Nil, Conflict of Interest: None declared.
Vol. 8 (Supplement 1), November 2014
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