Effect of intravenous dexmedetomidine on sensory
block duration in spinal anesthesia for lower limb
surgery: a randomized controlled trial

Simran Chahal; Anju R. Bhalotra; Rahil Singh; Shweta Dhiman; Snigdha Singh

doi:10.1016/j.bjane.2025.844672

Original Investigation

Effect of intravenous dexmedetomidine on sensory block duration in spinal anesthesia for lower limb surgery: a randomized controlled trial

Efeito da dexmedetomidina intravenosa na duração do bloqueio sensorial em anestesia espinhal para cirurgia de membros inferiores: um ensaio clínico randomizado

Simran Chahal, Anju R. Bhalotra, Rahil Singh, Shweta Dhiman, Snigdha Singh

http://dx.doi.org/10.1016/j.bjane.2025.844672 Braz J Anesthesiol, vol.75, n6, 844672, 2025

PDF

Downloads: 0

Abstract

Study objective

To study the effect of Intravenous (IV) dexmedetomidine during spinal anesthesia on duration of sensory block and postoperative analgesia in patients undergoing lower limb orthopedic surgery.

Design

Prospective randomized double blind controlled trial.

Intervention

Patients in intervention (DX) group received 0.5 mcg.kg⁻¹ IV dexmedetomidine over 10 min. Spinal anesthesia was administered and an infusion of dexmedetomidine 0.5 mcg.kg⁻¹.h⁻¹ was given throughout surgery.

Measurements

Onset time of sensory and motor block, maximum height of sensory block and duration of sensory and motor block were assessed. Intraoperative Heart Rate (HR), Blood Pressure (BP), Peripheral Oxygen Saturation (SpO₂), sedation scores, postoperative pain scores, time to requirement of ﬁrst analgesic and analgesic consumption over ﬁrst 24h were noted.

Results

Data of 58 ASA I/II adults was analyzed. Duration of sensory block, deﬁned as time to two-dermatome regression, was 137.03 ± 25.02 min in DX group and 79.45 ± 11.27 min in the NS group (p = 0.000). Onset of sensory and motor block and maximum height of sensory block were similar. Postoperative VAS scores were lower in the DX group at 4h and 24h (p = 0.001, p = 0.0001) and comparable at 0h, 8h and 12h. Time to requirement of postoperative analgesia was longer in the DX group (p < 0.001) and requirement of postoperative analgesics was higher in the NS group. Sedation scores and incidence of bradycardia were higher in the DX group, but hypotension was similar.

Conclusion

IV dexmedetomidine (0.5 mcg.kg⁻¹ followed by 0.5 mcg.kg⁻¹.h⁻¹) resulted in extended sensory and motor block, prolonged postoperative analgesia and reduced postoperative analgesic consumption with minimal side effects.

Keywords

Dexmedetomidine; Postoperative analgesia; Sensory block; Spinal anaesthesia

Resumo

Introdução

Investigar o efeito da dexmedetomidina intravenosa (IV) durante anestesia espinhal sobre a duração do bloqueio sensorial e analgesia pós-operatória em pacientes submetidos à cirurgia ortopédica de membros inferiores.

Desenho do estudo

Ensaio clínico prospectivo, randomizado, duplo-cego e controlado.

Intervenção

Os pacientes do grupo intervenção (DX) receberam dexmedetomidina IV 0,5 mcg.kg⁻¹ ao longo de 10 minutos. A anestesia espinhal foi administrada e uma infusão contínua de dexmedetomidina 0,5 mcg.kg⁻¹.h⁻¹ foi mantida durante toda a cirurgia.

Medições

Foram avaliados o tempo de início do bloqueio sensorial e motor, altura máxima do bloqueio sensorial e duração do bloqueio sensorial e motor. Também foram monitorados: frequência cardíaca (FC), pressão arterial (PA), saturação periférica de oxigênio (SpO₂), escores de sedação, escores de dor pós-operatória, tempo até a necessidade do primeiro analgésico e consumo de analgésicos nas primeiras 24 horas.

Resultados

Os dados de 58 adultos ASA I/II foram analisados. A duração do bloqueio sensorial, definida como o tempo para regressão de dois dermátomos, foi de 137,03 ± 25,02 min no grupo DX e 79,45 ± 11,27 min no grupo NS (p = 0,000). O início do bloqueio sensorial e motor e a altura máxima do bloqueio sensorial foram semelhantes entre os grupos. Os escores de dor pós-operatória (VAS) foram menores no grupo DX aos intervalos de 4h e 24h (p = 0,001, p = 0,0001) e comparáveis aos de 0h, 8h e 12h. O tempo até a necessidade de analgesia pós-operatória foi maior no grupo DX (p < 0,001) e o consumo de analgésicos pós-operatórios foi maior no grupo NS. Os escores de sedação e a incidência de bradicardia foram mais altos no grupo DX, mas a hipotensão foi semelhante.

Conclusão

A dexmedetomidina IV (0,5 mcg.kg⁻¹ seguida de infusão de 0,5 mcg.kg⁻¹.h⁻¹) prolongou o bloqueio sensorial e motor, aumentou a duração da analgesia pós-operatória e reduziu o consumo de analgésicos pós-operatórios, com efeitos colaterais mínimos.

Palavras-chave

Dexmedetomidina; Analgesia pós-operatória; Bloqueio sensorial; Anestesia espinhal

References

1. Kanazi GE, Aouad MT, Jabbour-Khoury SI, et al. Effect of low-dose dexmedetomidine or clonidine on the characteristics of bupivacaine spinal block. Acta Anaesthesiol Scand. 2006;50:222−7.

2. Belgrami SAH, Kumar M, Singh D, Priye S. A comparison of fentanyl, dexmedetomidine, and the combination of fentanyl with dexmedetomidine on the quality of subarachnoid block and postoperative analgesia: A double-blind controlled study. Indian J Anaesth. 2022;66(Suppl 4):S220−4.

3. Tang C, Xia Z. Dexmedetomidine in perioperative acute pain management: a non-opioid adjuvant analgesic. J Pain Res. 2017;10:1899−904.

4. Kanazi GE, Aouad MT, Jabbour-Khoury SI, et al. Effect of low-dose dexmedetomidine or clonidine on the characteristics of bupivacaine spinal block. Acta Anaesthesiol Scand. 2006;50:222−7.

5. Smith C, Birnbaum G, Carter JL, Greenstein J, Lublin FD. Tizanidine treatment of spasticity caused by multiple sclerosis. Neurology. 1994;44:34−43.

6. Kaya FN, Yavascaoglu B, Turker G, et al. Intravenous dexmedetomidine, but not midazolam, prolongs bupivacaine spinal anesthesia. Can J Anaesth. 2010;57:39−45.

7. Kavya UR, Laxmi S, Ramkumar V. Effect of intravenous dexmedetomidine administered as bolus or as bolus-plus-infusion on subarachnoid anesthesia with hyperbaric bupivacaine. J Anaesthesiol Clin Pharmacol. 2018;34:46−50.

8. Harsoor S, Rani DD, Yalamuru B, Sudheesh K, Nethra S. Effect of supplementation of low dose intravenous dexmedetomidine on characteristics of spinal anaesthesia with hyperbaric bupivacaine. Indian J Anaesth. 2013;57:265−9.

9. Bhirud PH, Chellam S, Mote MN, Toal PV. Effects of intravenous dexmedetomidine on spinal anesthesia and sedation - A comparison of two different maintenance infusions. J Anaesthesiol Clin Pharmacol. 2020;36:78−82.

10. Schnabel A, Meyer-Frießem CH, Reichl SU, Zahn PK, PogatzkiZahn EM. Is intraoperative dexmedetomidine a new option for postoperative pain treatment? A meta-analysis of randomized controlled trials. Pain. 2013;154:1140−9.

11. Verret M, Le JBP, Lalu MM, et al. Effectiveness of dexmedetomidine on patient-centred outcomes in surgical patients: a systematic review and Bayesian meta-analysis. Br J Anaesth. 2024;133:615−27.

12. Bijur PE, Silver W, Gallagher EJ. Reliability of the Visual Analog Scale for measurement of acute pain. Acad Emerg Med. 2001;8:1153−7.

13. Ramsay MAE, Savege TM, Simpson BRJ, Goodwin R. Controlled sedation with alphaxalone-alphadolone. BMJ. 1974;2:656−9.

14. Lee S. Dexmedetomidine: Present and future directions. Korean J Anesthesiol. 2019;72:323−30.

15. Afonso J, Reis F. Dexmedetomidine: current role in anesthesia and intensive care. Rev Bras Anestesiol. 2012;62:118−33.

16. Hamed Ahmed MS, Talaat Sahar M. Effect of intravenous versus intrathecal low-dose dexmedetomidine on spinal block in lower limb orthopedic surgery. Ain-Shams J Anaesthesiol. 2014;7:205−10.

17. Mohammed A, Ellisy K, Afifi M, Abdullah S. Intrathecal versus intravenous dexmedetomidine in characteristics of bupivacaine spinal block in lower abdominal surgery. Menoufia Med J. 2016;29:523−9.

18. Alshawadfy A, Elsadany MA, Elkeblawy AM, El-Lilly AA. Intravenous versus intrathecal dexmedetomidine as an additive to hyperbaric bupivacaine in spinal anesthesia for hip arthroplasty: A randomized controlled trial. Egypt J Anaesth. 2022;38:342−8.

19. Hong J, Kim WO, Yoon Y, Choi Y, Kim S, Kil HK. Effects of intravenous dexmedetomidine on low-dose bupivacaine spinal anaesthesia in elderly patients. Acta Anaesthesiol Scand. 2012;56:382−7.

20. Dinesh CN, Sai Tej NA, Yatish B, Pujari VS, Mohan Kumar RM, Mohan CV. Effects of intravenous dexmedetomidine on hyperbaric bupivacaine spinal anesthesia: A randomized study. Saudi J Anaesth. 2014;8:202−8.

21. Santpur MU, Kahalekar GM, Saraf N, Losari A. Effect of intravenous dexmedetomidine on spinal anaesthesia with 0.5% hyperbaric bupivacaine in lower abdominal surgeries: A prospective randomized control study. Anesth Essays Res. 2016;10:497−501.

22. Kumari R, Kumar A, Kumar S, Singh R. Intravenous dexmedetomidine as an adjunct to subarachnoid block: A simple effective method of better perioperative efficacy. J Anaesthesiol Clin Pharmacol. 2017;33:203−8.

23. Thakuria R, Jyoti Borah T, Sonowal J, Choudhury D. Effects of intravenous dexmedetomidine on 0.5% hyperbaric bupivacaine spinal anesthesia - A placebo-controlled randomized trial. Indian J Clin Anaesth. 2018;5:423−30.

24. Jung SH, Lee SK, Lim KJ, et al. The effects of single-dose intravenous dexmedetomidine on hyperbaric bupivacaine spinal anesthesia. J Anesth. 2013;27:380−4.

25. Lee MH, Ko JH, Kim EM, Cheung MH, Choi YR, Choi EM. The effects of intravenous dexmedetomidine on spinal anesthesia: comparison of different dose of dexmedetomidine. Korean J Anesthesiol. 2014;67:252−7.

26. Bharthi Sekar E, Vijayaraghavan U, Sadiqbasha AM. Effect of Intravenous Dexmedetomidine on Spinal Anesthesia. Cureus. 2021;13:e15708.

27. Farouk I, Hassan MM, Fetouh AM, Elgayed AEA, Eldin MH, Abdelhamid BM. Analgesic and hemodynamic effects of intravenous infusion of magnesium sulphate versus dexmedetomidine in patients undergoing bilateral inguinal hernial surgeries under spinal anesthesia: A randomized controlled study. Braz J Anesthesiol. 2021;71:489−97.

28. Dutta S, Choudhury A, Bandopadhyay D, Mondal S. Effect of dexmedetomidine infusion on characteristics of spinal anesthesia with hyperbaric bupivacaine: A randomized controlled trial. Int J Sci Res Arch. 2024;12:386−93.

29. Krishna AS, Agarwal J, Khanuja S, Kumar S, Khan A, Butt KM. Comparison of intravenous dexmedetomidine versus ketaminedexmedetomidine combination on spinal block characteristics in patients undergoing lower limb orthopedic surgery − A randomized clinical trial. Indian J Anaesth. 2024;68:795−800.

30. Reddy VS, Shaik NA, Donthu B, Reddy Sannala VK, Jangam V. Intravenous dexmedetomidine versus clonidine for prolongation of bupivacaine spinal anesthesia and analgesia: A randomized double-blind study. J Anaesthesiol Clin Pharmacol. 2013;29:342−7.

31. Gupta K, Tiwari V, Gupta PK, Pandey MN, Agarwal S, Arora A. Prolongation of subarachnoid block by intravenous dexmedetomidine for sub umbilical surgical procedures: A prospective control study. Anesth Essays Res. 2014;8:175−8.

32. Kubre J, Sethi A, Mahobia M, Bindal D, Narang N, Saxena A. Single dose intravenous dexmedetomidine prolongs spinal anesthesia with hyperbaric bupivacaine. Anesth Essays Res. 2016;10:273−7.

33. Sharma A, Varghese N, Venkateswaran R. Effect of intrathecal dexmedetomidine versus intravenous dexmedetomidine on subarachnoid anesthesia with hyperbaric bupivacaine. J Anaesthesiol Clin Pharmacol. 2020;36:381−5.

34. Furqan A, Mohsin MU, Sattar MK, Khan AA, Shahid M, Fayyaz A. Intravenous dexmedetomidine has synergistic effect on subarachnoid block with hyperbaric bupivacaine. Cureus. 2019;11: e6051.

35. Gerlach AT, Dasta JF. Dexmedetomidine: An updated review. Ann Pharmacother. 2007;41:245−54.

36. Gallagher EJ, Liebman M, Bijur PE. Prospective validation of clinically important changes in pain severity measured on a visual analog scale. Ann Emerg Med. 2001;38:633−8.

37. Farrar JT, Portenoy RK, Berlin JA, Kinman JL, Strom BL. Defining the clinically important difference in pain outcome measures. Pain. 2000;88:287−94.

Submitted date:
01/25/2025

Accepted date:
07/31/2025