Brazilian Journal of Anesthesiology
Brazilian Journal of Anesthesiology
Clinical Research

Intravenous magnesium sulfate for postoperative analgesia after abdominal hysterectomy under spinal anesthesia: a randomized, double-blind trial

Sulfato de magnésio intravenoso para analgesia pós-operatória após histerectomia abdominal sob anestesia espinhal: um estudo duplo-cego randomizado

Márcio Luiz Benevides, Danielle Carvalho Fialho, Daiane Linck, Ana Luiza Oliveira, Dennis Henrique Vieira Ramalho, Marília Marquioreto Benevides

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Background and objectives
Abdominal Hysterectomy (AH) is associated with significant inflammatory response and can result in moderate to severe postoperative pain. This study aimed to evaluate the efficacy of magnesium infusion in reducing postoperative pain and analgesic consumption after AH under spinal anesthesia with Intrathecal Morphine (ITM).

Eighty-six patients were included in this clinical, controlled, randomized, double-blind study. Patients received in Group Mg, MgSO4 50 mg kg−1 for 15-minutes followed by 15-mg kg−1 h−1 until the end of the surgery; and in Group C, (control) the same volume of isotonic saline. Both groups received 100 μg of ITM. All patients received dipyrone + ketoprofen intraoperatively and postoperatively, and dexamethasone intraoperatively only. We evaluated the intensity of pain, tramadol consumption, and adverse events 24 h postoperatively.

Serum magnesium concentrations were higher in Group Mg at the end, and one hour after the operation (p = 0.000). Postoperative pain scores were reduced in Group Mg at 6-hours at rest and on movement (p < 0.05). Tramadol consumption did not show a statistically significant difference between Group Mg and Group C (15.5 ± 36.6 mg and 29.2 ± 67.8 mg respectively, p = 0.53). Hemodynamic variables, the incidence of pruritus, nausea, and vomiting were similar in the two groups.

Infusion of MgSO4 during AH undergoing spinal anesthesia with ITM reduced at 6-hours at rest and on movement. More studies should be performed to evaluate the potential antinociceptive effect of MgSO4 in scenarios where a multimodal analgesia approach was employed.


Hysterectomy;  Magnesium sulfate;  Tramadol;  Postoperative pain;  Spinal anesthesia;  Morphine


Justificativa e objetivos: A histerectomia abdominal (HA) está associada a uma resposta inflamatória significativa e pode resultar em dor pós-operatória moderada a intensa. Este estudo teve como objetivo avaliar a eficácia da infusão de magnésio na redução da dor pós-operatória e do consumo de analgésicos após HA sob raquianestesia com Morfina Intratecal (MIT). Método: Oitenta e seis pacientes foram incluídas neste estudo clínico, controlado, randomizado e duplo-cego. As pacientes receberam no Grupo MgSO4 50 mg kg −1 por 15 minutos seguido de 15 mg kg −1 h −1 até o final da cirurgia; e no Grupo C, (controle) o mesmo volume de solução salina isotônica. Ambos os grupos receberam 100 g de MIT. Todas as pacientes receberam dipirona + cetoprofeno no intra e pós-operatório e dexametasona apenas no intraoperatório. Avaliamos a intensidade da dor, o consumo de tramadol e os eventos adversos 24 horas no pós-operatório. Resultados: As concentrações de magnésio sérico foram maiores no Grupo Mg no final e uma hora após a operação (p = 0,000). Os escores de dor pós-operatória foram reduzidos no Grupo Mg em 6 horas em repouso e em movimento (p <0,05). O consumo de tramadol não apresentou diferença estatisticamente significativa entre o Grupo Mg e o Grupo C (15,5 ± 36,6 mg e 29,2 ± 67,8 mg, respectivamente, p = 0,53). As variáveis hemodinâmicas, a incidência de prurido, náuseas e vômitos foram semelhantes nos dois grupos. Conclusão: A infusão de MgSO4 durante HA submetidos à raquianestesia com MIT reduziu após 6 horas em repouso e em movimento. Mais estudos devem ser realizados para avaliar o potencial efeito antinociceptivo do MgSO4 em cenários onde uma abordagem de analgesia multimodal foi empregada.


Histerectomia; Sulfato de magnésio; Tramadol; Dor pós-operatória; Raquianestesia; Morfina


1 J.W. Aarts, T.E. Nieboer, N. Johnson, et al. Surgical approach to hysterectomy for benign gynaecological disease Cochrane Database Syst Rev., 2015 (2015), p. CD003677

2 B. Brandsborg Pain following hysterectomy: epidemiological and clinical aspects Dan Med J., 59 (2012), p. B4374

3 T.K. Kim, J.R. Yoon Comparison of the neuroendocrine and inflammatory responses after laparoscopic and abdominal hysterectomy Korean J Anesthesiol., 59 (2010), pp. 265-269

4 A. Beverly, A.D. Kaye, O. Ljungqvist, R.D. Urman Essential Elements of Multimodal Analgesia in Enhanced Recovery After Surgery (ERAS) Guidelines Anesthesiol Clin., 35 (2017), pp. e115-e143

5 L. Azari, J.T. Santoso, S.E. Osborne Optimal pain management in total abdominal hysterectomy Obstet Gynecol Surv., 68 (2013), pp. 215-227

6 N.B. Wodlin, L. Nilsson, Arestedt Mode of anesthesia and postoperative symptoms following abdominal hysterectomy in a fast-track setting Acta Obstet Gynecol Scand., 90 (2011), pp. 369-379

7 A. Hein, P. Rösblad, Gillis-Haegerstrand, et al. Low dose intrathecal morphine effects on post-hysterectomy pain: a randomized placebo-controlled study Anaesthesiol Scand., 56 (2012), pp. 102-109, 10.1111/j.1399-6576.2011.02574.x

8 N. Borendal Wodlin, L. Nilsson, P. Carlsson, P. Kjølhede Cost-effectiveness of general anesthesia vs spinal anesthesia in fast-track abdominal benign hysterectomy Am J Obstet Gynecol., 205 (2011) 326.e1326.e3267

9 G. Baldini, F. Carli Anesthetic and adjunctive drugs for fast-track surgery Curr Drug Targets., 10 (2009), pp. 667-686

10 E.N. Brown, K.J. Pavone, M. Naranjo Multimodal General Anesthesia: Theory and Practice Anesth Analg., 127 (2018), p. 12461258

11 Do. Sang-Hwan Magnesium: a versatile drug for anesthesiologists Korean J Anesthesiol., 65 (2013), pp. 4-8

12 M.A. Ramsay, T.M. Savege, B.R. Simpson, R. Goodwin Controlled sedation with alphaxalone-alphadolone Br Med J., 2 (1974), pp. 656-659

13 J.A. Aldrete The Post-Anesthetic Recovery Score Revisited J Clin Anesth., 7 (1995), pp. 89-91

14 L.J. Catro-Alves, V.L. De Azevedo, T.F. De Freitas Braga, A.C. Goncalves, G.S. De Oliveira Jr. The effect of neuraxial versus general anesthesia techniques on postoperative quality of recovery and analgesia after abdominal hysterectomy: a prospective, randomized, controlled trial Anesth Analg., 113 (2011), pp. 1480-1486

15 S. Khorasanizadeh, M. Panahi, G. Mohseni, et al. Comparison of analgesia in subcutaneous infiltration of ropivacaine and magnesium sulfate for postoperative pain control of cholecystectomy Novel Biomed., 8 (2020), pp. 13-19

16 M. Bujalska-Zadrożny, J. Tatarkiewicz, K. Kulik, M. Filip, M. Naruszewicz Magnesium enhances opioid-induced analgesia – What we have learnt in the past decades? Eur J Pharm Sci., 99 (2017), pp. 113-127

17 J.Y. Hwang, H.S. Na, Y.T. Jeon, et al. Infusion of magnesium sulphate during spinal anaesthesia improves postoperative analgesia Br J Anaesth., 103 (2009), pp. 861-866

18 A. Agrawal, S. Agrawal, Y.S. payal Effect of continuous magnesium sulfate infusion on spinal block characteristics: A prospective study Saudi J Anaesth., 8 (2014), pp. 78-82

19 J.H. Ryu, M.H. Kang, K.S. Park, S.H. Do Effects of magnesium sulphate on intraoperative anesthetic requirements and postoperative analgesia in gynecology patients receiving total intravenous anesthesia Br J Anaesth., 100 (2008), pp. 397-403

20 T.O. Seyhan, M. Tugrul, M.O. Sungur, et al. Effects of three different dose regimens of magnesium on propofol requirements, haemodynamic variables and postoperative pain relief in gynaecological surgery Br J Anaesth., 96 (2006), pp. 247-252

21 E. Albrecht, K.R. Kirkham, S.S. Liu, R. Brull Peri-operative intravenous administration of magnesium sulphate and postoperative pain: a meta-analysis Anaesthesia., 68 (2013), pp. 79-90

22 A. Taheri, K. Haryalchi, M. Mansour Ghanaie, N. Habibi Arejan Effect of low-dose (single-dose) magnesium sulfate on postoperative analgesia in hysterectomy patients receiving balanced general anesthesia Anesthesiol Res Pract., 2015 (2015), p. 306145

23 S. Asadollah, M. Vahdat, P. Yazdkhasti, et al. Magnesium sulphate on postoperative analgesia requirements 2015 J Turk Soc Obstet Gynecol., 1 (2015), pp. 34-37

24 K. Haryalchi, M. Abedinzade, K. Khanaki, et al. Whether preventive low dose magnesium sulphate infusion has an influence on postoperative pain perception and the level of serum beta-endorphin throughout the total abdominal hysterectomy Rev Esp Anestesiol Reanim., 64 (2017), pp. 384-390

25 S. Ghaffaripour, H. Mahmoudi, H. Eghbal, et al. The effect of intravenous magnesium sulfate on post-operative analgesia during laminectomy Cureus., 8 (2016), p. e626

26 V. Ghezel-Ahmadi, D. Ghezel-Ahmadi, J. Schirren, et al. Perioperative systemic magnesium sulphate to minimize acute and chronic post-thoracotomy pain: a prospective observational study J Thorac Dis., 11 (2019), pp. 418-426

27 C. Chen, R. Tao The impact of magnesium sulfate on pain control after 28. laparoscopic cholecystectomy: a meta-analysis of randomized controlled studies Surg Laparosc Endosc Percutan Tech., 28 (2018), pp. 349-353

28 F. Kahraman, A. Eroglu The effect of intravenous magnesium sulfate infusion on sensory spinal block and postoperative pain score in abdominal hysterectomy BioMed Research International., 2014 (2014), p. 236024

29 P.N. Shah, Y. Dhengle Magnesium sulfate for postoperative analgesia after surgery under spinal anesthesia Acta Anaesthesiol Taiwan., 54 (2016), pp. 62-64

30 H.Y. Zhong, W.P. Zhang Effect of intravenous magnesium sulfate on bupivacaine spinal anesthesia in preeclamptic patients Biomed Pharmacother., 108 (2018), pp. 1289-1293

31 H.J. Shin, E.Y. Kim, H.S. Na, T.K. Kim, M.H. Kim, S.H. Do Magnesium sulphate attenuates acute postoperative pain and increased pain intensity after surgical injury in staged bilateral total knee arthroplasty: a randomized, double-blinded, placebo-controlled trial Br J Anaesth., 117 (2016), pp. 497-503

32 L. Frassanito, A. Messina, A. Vergari, et al. Intravenous infusion of magnesium sulfate and postoperative analgesia in total knee arthroplasty Minerva Anestesiol., 81 (2015), pp. 1184-1191

33 Y.N. Peng, F.C. Sung, M.L. Huang, et al. The use of intravenous magnesium sulfate on postoperative analgesia in orthopedic surgery A systematic review of randomized controlled trial Medicine (Baltimore)., 97 (2018), p. e13583

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