Adding different doses of intrathecal magnesium sulfate for spinal anesthesia in the cesarean section: A prospective double blind randomized trial

Authors

1 Department of Anesthesiology, Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran

2 Resident of Anesthsiology, Anesthesiology and Critical Care Research Center, Isfahan University of Medical Sciences, Isfahan, Iran

Abstract

Background: There is uncertainty as to whether addition of magnesium sulfate to spinal local anesthetics improves quality and duration of block in the caesarean section. In this randomized double blind clinical trial study, we investigated the effect of adding different doses of intrathecal magnesium sulfate to bupivacaine in the caesarean section.
Materials and Methods: After institutional approval and obtaining informed patient consent, 132 ASA physical status I-II women undergoing elective cesarean section with spinal anesthesia were randomized to four groups: 1−2.5 cc Bupivacaine 0.5%+ 0.2 cc normal saline (group C) 2− 2.5 cc Bupivacaine 0.5%+ 0.1 cc normal saline+ 0.1 cc magnesium sulfate 50% (group M 50 ) 3− 2.5 cc Bupivacaine 0.5%+ 0.05 cc normal saline+ 0.15 cc magnesium sulfate 50% (group M 75 ) 4− 2.5 cc Bupivacaine 0.5%+ 0.2 cc magnesium sulfate 50% (group M 100 ). Patients and staff involved in data collections were unaware of the patient group assignment. We recorded the following: onset and duration of block, time to complete motor block recovery, and analgesic requirement.
Results: Magnesium sulfate caused a delay in the onset of both sensory and motor blockade. The duration of sensory and motor block were longer in M 75 and M 100 groups than group C (P < 0.001). Recovery time was shorter in group C (P < 0.001) and analgesic requirement was more in group C than others (P < 0.001).
Conclusions: In patients undergoing the caesarean section under hyperbaric bupivacaine spinal anesthesia, the addition of 50, 75, or 100 mg magnesium sulfate provides safe and effective anesthesia, but 75 mg of this drug was enough to lead a significant delay in the onset of both sensory and motor blockade, and prolonged the duration of sensory and motor blockade, without increasing major side effects.

Keywords

1. Yousef AA, Amr YM. The effect of adding magnesium sulphate to epidural bupivacaine and fentanyl in elective Cesarean Section using combined spinal-epidural anesthesia: A prospective double blind randomized study. Int J Obstet Anesth 2010;19:401-4.  Back to cited text no. 1
    
2. Ashburn MA, Love G, Pace NL. Respiratory-related critical events with intravenous patient-controlled analgesia. Clin J Pain 1994;10:52-6.  Back to cited text no. 2
    
3. Dayioglu H, Baykara ZN, Salbes A, Solak M, Toker K. Effects of adding magnesium to bupivacaine and fentanyl for spinal anesthesia in knee arthroscopy. J Anesth 2009;23:19-25.  Back to cited text no. 3
    
4. Ascher P, Nowak L. Electrophysiological studies of NMDA receptors. Trends Neurosci 1987;10:284-8.  Back to cited text no. 4
    
5. Xiao WH, Bennet GJ. magnesium suppresses neuropathic pain responses in rat via a spinal site of action. Brain Res 1994;666:168-72.  Back to cited text no. 5
    
6. Tramer MR, Schneider J, Marti RA, Rifat K. Role of magnesium sulfate in postoperative analgesia. Anesthesiology 1996;84:340-7.  Back to cited text no. 6
    
7. Katz J, Kavanagh BP, Sandler AN, Nierenberg H, Boylan JF, Friedlander M, et al. Preemetive analgesia: Clinical evidence of neuroplasticity contributing to postoperative pain. Anesthesiology 1992;77:439-46.  Back to cited text no. 7
    
8. Kroin JS, McCarthy RJ, Von Roenn N, Schwab B, Tuman KJ, Ivankovich AD. Magnesium sulfate potentiates morphine antinociception at the spinal level. Anesth Analg 2000;90:913-7.  Back to cited text no. 8
    
9. Buvanendran A, McCarthy RJ, Kroin JS, Leong W, Perry P, Tuman KJ. Intrathecal magnesium prolongs fentanyl analgesia: A prospective, randomized, controlled trial. Anesth Analg 2002;95:661-6.  Back to cited text no. 9
    
10. Khalili G, Janghorbani M, Sajedi P, Ahmadi G. Effects of adjunct intrathecal magnesium sulfate to bupivacaine for spinal anesthesia: A randomized double-blind trial in patients undergoing lower extremity surgery. J Anesth 2011;25:892-7.  Back to cited text no. 10
    
11. Ghrab BE, Maatoug M, Kallel N, Khemakhem K, Chaari M, Kolsi K, et al. Does Combination of intrathecal magnesium sulfate and morphine improve postcaesarean section analgesia? Ann Fr Anesth Rean 2009;28:454-9.  Back to cited text no. 11
    
12. Arcioni R, Palmisani S, Tigano S, Santorsola C, Sauli V, Romanò S, et al. Combined intrathecal and epidural magnesium sulfate supplementation of spinal anesthesia to reduce post-operative analgesic requirements: A prospective, randomized, double-blinded controlled trial in patients with undergoing major orthopedic surgery. Acta Anesthesiol Scand 2007;51:482-9.  Back to cited text no. 12
    
13. Lejuste MJ. Inadvertent intrathecal administration of magnesium sulfate. S Afr Med J 1985;68:367-8.  Back to cited text no. 13
    
14. Dickenson AH. NMDA receptor antagonists: Interaction with opioids. Acta Anaesthesiol Scand 1997;41:112-5.  Back to cited text no. 14
    
15. Ozalevli M, Cetin TO, Unlugence H. The effect of adding intrathecal magnesium sulphate to bupivacaine-fentanyl spinal anesthesia. Acta Anaesthesiol Scan 2005;49:1514-9.  Back to cited text no. 15
    
16. Simpson JI, Eide TR, Schiff GA, Clagnaz JF, Hossain I, Tverskoy A, et al. Intrathecal magnesium sulfate protects the spinal cord from ischemic injury during thoracic aortic cross clamping. Anesthesiology 1994;81:1493-9.  Back to cited text no. 16
    
17. Karaman S, Kocaba M. The Effective of sufentanil or morphine added to hyperbaric bupivacaine in spinal anesthesia for caesarean section. European Journal of Anesthesia 2006;23:285-91.  Back to cited text no. 17
    
18. Witlin AG, Sibai BM. Magnesium sulfate therapy in preeclampsia and eclampsia. Obstet Gynecol 1998;92:883-9.  Back to cited text no. 18
    
19. McCarthy RJ, Kroin JS, Tuman KJ, Penn RD, Ivankovich AD. Antinociceptive potentiation and attenuation of tolerance by intrathecal co-infusion of magnesium sulfate and morphine in rats. Anesth Analg 1998;86:830-6.  Back to cited text no. 19