|Year : 2020 | Volume
| Issue : 2 | Page : 176-181
Efficacy of adding magnesium sulfate to bupivacaine for ilioinguinal and iliohypogastric nerve block in acute postherniorrhaphy pain
Maha A Abo-Zeid, Mahmoud S.F El Mansy
Department of Anesthesia and Surgical Intensive Care, Faculty of Medicine, Mansoura University, Mansoura, Egypt
|Date of Submission||08-Oct-2019|
|Date of Acceptance||31-Oct-2019|
|Date of Web Publication||27-Jun-2020|
MD Maha A Abo-Zeid
Department of Anesthesia and Surgical Intensive Care, Faculty of Medicine, Mansoura University, Mansoura, 35516
Source of Support: None, Conflict of Interest: None
Background Regional block of ilioinguinal and iliohypogastric (IIIH) nerves has been applied to provide postoperative analgesia after inguinal hernia repair. Magnesium sulfate (MgSo4) blocks N-methyl-d-aspartate receptors, and that is why, it was used as an adjuvant to the local anesthetic (LA) in different anesthetic approaches. Although the prolongation in postoperative duration resulting from the addition of MgSO4 to LA was significant in some literature studies, it was insignificant in others.
Objective This study was designed to investigate the adjunctive effect of MgSo4 when added to bupivacaine for IIIH blockade on the postoperative analgesic duration as a primary outcome and on the verbal rating scale (VRS) scores, analgesic consumption, and hemodynamics as secondary outcomes.
Patients and methods Patients were divided into two groups of 45 patients each by means of coded envelopes according to the LA used for IIIH blockade. In the first group (control group), patients received 10 ml 0.5% isobaric bupivacaine plus 1 ml normal saline for IIIH blockade, whereas in the second group (MgSo4 group), 10 ml 0.5% isobaric bupivacaine and 1 ml of MgSo4 10% were prepared. All the patients received intrathecal 3 ml 0.5% hyperbaric bupivacaine, and then, IIIH blockade was performed under ultrasound guidance according to the group. Postoperatively, VRS scores, analgesic duration, and any complication were recorded.
Results There was a significantly prolonged analgesic duration in MgSo4 group when compared with the control group. However, the consumed analgesic in the first postoperative day and the pain score were insignificantly lower in MgSo4 group.
Conclusion The addition of MgSO4 to bupivacaine for IIIH nerve block prolonged the postoperative analgesic duration after inguinal hernia repair without significant effect on the analgesic consumption or VRS scores.
Keywords: iliohypogastric nerve, ilioinguinal nerve, magnesium sulfate
|How to cite this article:|
Abo-Zeid MA, El Mansy MS. Efficacy of adding magnesium sulfate to bupivacaine for ilioinguinal and iliohypogastric nerve block in acute postherniorrhaphy pain. Res Opin Anesth Intensive Care 2020;7:176-81
|How to cite this URL:|
Abo-Zeid MA, El Mansy MS. Efficacy of adding magnesium sulfate to bupivacaine for ilioinguinal and iliohypogastric nerve block in acute postherniorrhaphy pain. Res Opin Anesth Intensive Care [serial online] 2020 [cited 2020 Oct 28];7:176-81. Available from: http://www.roaic.eg.net/text.asp?2020/7/2/176/288003
| Introduction|| |
Inguinal herniorrhaphy is a common surgical procedure commonly performed as an outpatient surgery . The subsequent acute postoperative pain is a main complication affecting the ambulation start, gastrointestinal motility, and the hospital discharge . Thus, the preemptive analgesia during the anesthetic technique would provide better postoperative outcomes .
The ilioinguinal, iliohypogastric, and genital branch of genitofemoral nerve are the three sensory nerves crossing the inguinal canal in front of trasversalis fascia . Regional block of both ilioinguinal and iliohypogastric (IIIH) nerves had been successfully and safely applied for both children  and adults to provide postoperative analgesia after inguinal hernia repair .
Magnesium sulfate (MgSO4) prevents the central sensitization caused by peripheral nociceptive simulation through blocking the N-methyl-d-aspartate (NMDA) receptors, the excitatory receptors in the afferent transmission of nociceptive signals. Therefore, MgSO4 could potentiate the postoperative analgesia after tissue injury , and that is why, MgSO4 was used as an adjuvant to the local anesthetic (LA) in different anesthetic approaches ,,.
Although the prolongation in postoperative duration resulting from the addition of MgSO4 to LA was significant in some literatures , it was insignificant in others ,.
This study was designed to evaluate whether the addition of MgSO4 as an adjunctive in IIIH blockade will increase the postoperative analgesic duration or not as a primary outcome. The hemodynamics, verbal rating scale (VRS) scores, and analgesic consumption in first 24 h postoperatively were the secondary outcomes.
| Patients and methods|| |
After written consent, 90 adult male patients with American Society of Anesthesiologists physical status I or II, admitted to the surgical department scheduled for elective nonrelapsing unilateral inguinal herniorrhaphy under spinal anesthesia, were enrolled in this study. This prospective randomized double-blinded study was held after approval of the Mansoura Faculty of Medicine Institutional Review Board (MFM-IRB number R/17.03.59).
Patients with body mass index (BMI) greater than or equal to 35 kg/m2, allergy to the study drugs, or on chronic analgesics or drug containing magnesium were excluded from the study. Patients with spinal deformity; central or peripheral neuropathies; infection at the injection sites; coagulopathy; and severe renal, hepatic, or cardiac diseases were also excluded.
Patients were divided into two groups of 45 patients each, by means of coded envelopes according to the injectate used for IIIH blockade which was prepared by an anesthetist who was not involved in the perioperative assessment. For the first group (control group), 10-ml 0.5% isobaric bupivacaine and 1 ml normal saline were prepared for IIIH blockade. However, in the second group (MgSo4 group), 10 ml 0.5% isobaric bupivacaine and 1 ml of MgSo4 10% (100 mg) (Egyptian International Pharmaceuticals Industries Company) were used.
Before surgery, patients fasted and were instructed on using VRS (0=no pain and 10=worst imaginable pain). One hour before surgery, intravenous (i.v.) fluid preload 10 ml/kg Ringer’s solution was infused. After the patients’ arrival to the operating room, monitoring of heart rate (HR), mean blood pressure (MAP), and peripheral oxygen saturation (SpO2) was started with recording of baseline values. All the patients received intrathecal 3 ml 0.5% hyperbaric bupivacaine at lumbar 4–5 intervertebral space in the sitting position, under sterile conditions. The patients were turned to the supine position, and supplemental oxygen was delivered through a nasal cannula at 3 l/min.
Then, IIIH blockade was performed on the side of surgery under complete aseptic technique via a 13-MHz high-frequency linear ultrasound (US) transducer (clearVue 350-philips Ultrasound machine- United States). Scanning with oblique and transverses abdominis muscles. A short beveled 23-G needle was advanced perpendicularly. After negative aspiration test for blood, the LA was injected under vision of the dissecting of the space bounded by the hyperechoic fascial sheath of the internal oblique and transverse abdominis muscle layers.
Then the surgery was started with continuous infusion of 10 ml/kg/h Ringer’s solution. Any decrease in MAP of 20% or more from baseline values was determined as hypotension, which was managed with extra crystalloids infusion. If no response, i.v. increments of 5 mg ephedrine were given till correction. Bradycardia (HR decreased to <50 beats/min) was managed with 0.5 mg of i.v. atropine increments.
After completion of the surgery, the patients were transferred to the recovery room with recording of the surgical time. Then for all the patients, 1 g i.v. paracetamol was infused which was repeated every 8 h. Postoperative incisional pain was evaluated by VRS at 2, 4, 6, 12, 18, and 24 h postoperatively. If VRS greater than 3, 0.35 mg/kg i.v. meperidine was given. The postoperative analgesic duration, which was the time from IIIH injection to the first analgesic requirement, was recorded. Any perioperative complication was recorded and treated appropriately.
Statistical analysis was done using SPSS statistical package version 21 (SPSS Inc., Chicago, Illinois, USA). The data were examined for normal distribution using Shapiro–Wilk’s test. The parametric data were presented as mean±SD, and then Student t test was applied to compare between the two groups. Paired t-test was done to compare between measurements in the same group. The nonparametric data were presented as median (interquartile range), and for significance, Mann–Whitney test was done. For nonparametric data, χ2-test was used. Significance was considered when P value was less than 0.05.
According to the study of Toivonen et al. , the average postoperative analgesic duration after IIIH block with the same bupivacaine dose was 8.1 (0.9–54.7) h. Acceptance of a 25% increase in the analgesic duration (10.1 h) would be clinically significant. With assuming an α error of 0.05, β error of 0.2, and a power of 80%; it resulted in 41 patients in each group. Allowing for dropout of 10% so, 45 patients were needed in each group to detect the clinical effect.
| Result|| |
A total of 90 adult male patients who underwent inguinal hernia repair were enrolled in this study. There were no significant differences between the two groups regarding the demographic data (age, American Society of Anesthesiologists physical status, BMI, and surgical duration) ([Table 1]).
There were no significant differences regarding HR in the studied groups either intraoperatively or postoperatively in comparison with basal values ([Figure 1]). No patients in either group developed bradycardia. However, there was a significant decrease in the MAP in both groups immediately after spinal anesthesia in comparison with basal values (P=0.018 and 0.037 in control group and MgSo4 group, respectively). Moreover, there was a statistically significant decreased MAP in control group at 15 min after surgical incision when compared with the basal value (P=0.017) ([Figure 2]).
|Figure 1 Heart rate (beat per minute) of the studied groups. Values are mean±SD. IIIH, ilioinguinal-iliohypogastric; MgSO4, magnesium sulfate.|
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|Figure 2 Mean blood pressure (mmHg) of the studied groups. Values are mean±SD. IIIH, ilioinguinal-iliohypogastric; MgSO4, magnesium sulfate. †Significance in comparison with basal values of the control group; ‡significance in comparison with basal values of the MgSO4 group.|
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There were no significant differences between the two groups with respect to VRS ([Table 2]).
The total dose of meperidine consumption and the total analgesic requests in the first postoperative day were insignificantly lower in MgSo4 group when compared with the control group. The postoperative analgesia duration was significantly prolonged in MgSo4 group in comparison with the control group ([Table 3]).
No shivering, nausea, or vomiting occurred either intraoperatively or during the first 24 h postoperatively.
| Discussion|| |
In this study, MgSo4 was added to bupivacaine in IIIH nerve block for inguinal herniorrhaphy. This resulted in significantly prolonged analgesic duration in MgSo4 group when compared with the control group. However, the consumed analgesic in the first postoperative day (meperidine) was insignificantly lower in MgSo4 group.
Although with numerous analgesic options, the treatment of postoperative pain is sometimes unsatisfactory. Furthermore, most of the analgesics commonly used (e.g. opioids) are associated with many adverse effects and may not be highly effective in preventing postoperative pain .
Bupivacaine is a commonly used LA which provides long duration of blockade which could extend more when it is used with adjuvants. Various adjuvants (e.g. dexmedetomidine, opioids, ketamine, dexamethasone, and MgSo4) are used to prolong its analgesic duration and decrease the opioid requirements. Each of those adjuvants had a specific analgesic mechanism .
The perineural analgesic effect of MgSo4 besides blocking the NMDA receptors could be also explained by the surface charge theory. As the high concentrations of magnesium and calcium ions will be attracted by the outer membrane surface negative charges, so affecting the sodium channel gating produces hyperpolarization. When the nerve fiber is hyperpolarized, it is difficult to reach the threshold level leading to blockade of the nerve conduction .
The prolonged analgesic duration following the addition of MgSo4 seen in this study is supported by many studies. Gunduz et al.  examined the effect of perineural 100 mg MgSO4 added to prilocaine on the axillary plexus block duration. They reported a significantly prolonged duration of sensory block (4.2±0.3 h) after MgSO4 compared with the control group (3.2±0.5 h). Moreover, the addition of 3 ml MgSO4 20% to lidocaine (5 mg/kg) in axillary plexus block by Haghighi et al.  showed prolonged duration of sensory block (248.83±18.36 min in magnesium group and 204.67±22.62 min in control group), which is in parallel to the existing study. Furthermore, a study by Yangtse et al.  revealed that addition of 2 ml MgSO4 10% to LA for supraclavicular brachial plexus block prolonged the analgesic duration but with significant decrease in the amount of rescue analgesia, which is opposite to that of this study.
In this study, although there was significantly prolonged postoperative analgesic duration in MgSO4 group, there was no significant reduction in the VRS scale or in the analgesic consumption. In contrast to this finding, Ekmekci et al.  added MgSO4 to levobupivacaine for femoral nerve block and revealed significant lower analgesic consumption (tramadol) and VRS (at 4, 6, 12, and 24 h postoperatively). This could be explained by using 150 mg MgSO4, which is larger than the dose used in the current study.
However, the nonsignificant decrease in VRS scale and the analgesic consumption was in agreement with the study of Choi et al. , who added 2 ml MgSO4 10% to 20 ml ropivacaine 0.2% in axillary brachial plexus block. They reported that using MgSO4 did not reduce the opioid consumption or the postoperative pain scores. However, in their study, no comment was made on the analgesic duration. Moreover, a study by Lee et al.  used 2 ml MgSO4 10% to 20 ml bupivacaine 0.5% in interscalene nerve block revealed a significantly prolonged postoperative analgesic duration. But no significant decrease in the amount of rescue analgesia was recorded. Also, pain numeric rating scale showed once a significant decrease (after 12 hours postoperatively). This is almost the same finding as that of the current study, although they used double the MgSO4 dose with epinephrine (1 : 200000). The absence of any postoperative adverse effects especially in MgSO4 group was in parallel to the findings in a study on axillary plexus block, even with larger dose of MgSO4 (600 mg) .
Regarding MAP, there was a significant decrease in both groups immediately after spinal anesthesia in comparison with their basal values. Moreover, there was a significant decrease in the control group at 15 min after surgical incision in comparison with the basal value. These could be explained mainly owing to the sympathetic block after spinal anesthesia that leads to vasodilatation and hypotension .
In this study, only one dose of MgSO4 was used without seeing the effect of other larger concentrations, which may improve the analgesic profile.
| Conclusion|| |
The addition of MgSO4 to bupivacaine for IIIH block prolonged the postoperative analgesic duration after inguinal hernia repair without significant effect on the analgesic consumption or VRS scores.
Manuscrit has been read, approved, and revised by all the authors. Each author believes that this manuscript represents honest work.
Dr Maha A. Abozeid was responsible for the idea of the research, the design of the protocol, clinical work, data collection, the statistical analysis, and writing and revision of the manuscript; the corresponding author, Dr Mahmoud S. Fares, was responsible for the idea of the research, the design of the protocol, clinical work, data collection, the statistical analysis, and writing and revision of the manuscript.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Rutkow IM. Demographic and socioeconomic aspects of hernia repair in the United States in 2003. SurgClin North Am 2003; 83:1045–1051.
Hon SF, Poon CM, Leong HT, Tang YC. Pre-emptive infiltration of bupivacaine in laparoscopic total extraperitonealhernioplasty: a randomized controlled trial. Hernia 2009; 13:53–56.
Guilherme de Castro Santos G de C, Braga GM, Queiroz FL, Navarro TP, Gomez RS. Assessment of postoperative pain and hospital discharge after inguinal and iliohypogastric nerve block for inguinal hernia repair under spinal anesthesia: a prospective study. Rev Assoc Med Bras 2011; 57:535–538.
Wijsmuller AR, Lange JF, Kleinrensink GJ, van Geldere D, Simons MP, Huygen FJ et al.
Nerve-identifying inguinal hernia repair: a surgical anatomical study. World J Surg 2007; 31:414–420.
Carré P, Mollet J, Le Poultel S, Costey G, Ecoffey C. Ilio-inguinal Iliohypogastric nerve block with a single puncture: an alternative for anesthesia in emergency inguinal surgery. Ann Fr Anesth Reanim 2001; 20:643–646.
Andersen FH, Nielsen K, Kehlet H. Combined ilioinguinal blockade and local infiltration anaesthesia for groin hernia repair − a double-blind randomized study. Br J Anaesth 2005; 94:520–523.
Bilir A, Gulec S, Erkan A, Ozcelik A.Epidural magnesium reduces postoperative analgesic requirement. Br J Anesth 2007; 98:519–523.
Rana S, Verma RK, Singh J, Chaudhary SK, Chandel A. Magnesium sulphate as an adjuvant to bupivacaine in ultrasound-guided transversus abdominis plane block in patients scheduled for total abdominal hysterectomy under subarachnoid block. Indian J Anaesth 2016; 60:174–179.
] [Full text]
Imani F, Rahimzadeh P, Faiz HR, Abdullahzadeh-Baghaei A. An evaluation of the adding magnesium sulfate to ropivacaine on ultrasound-guided transverse abdominis plane block after abdominal hysterectomy. Anesth Pain Med 2018; 8:e74124.
Yousef AA, Amr YM. The effect of adding magnesium sulphate to epidural bupivacaine and fentanyl in elective caesarean section using combined spinal-epidural anaesthesia: a prospective double blind randomised study. Int J Obstet Anesth 2010; 19:401–404.
Toivonen J, Permi J, Rosenberg PH. Effect of preincisional ilioinguinal and iliohypogastric nerve block on postoperative analgesic requirement in day-surgery patients undergoing herniorrhaphy under spinal anaesthesia. Acta Anaesthesiol Scand 2001; 45:603–607.
Bellows CF, Berger DH. Infiltration of suture sites with local anesthesia for management of pain following laparoscopic ventral hernia repairs: a prospective randomized trial. JSLS 2006; 10:345–350.
Lagan G, McClure HA. Review of local anesthetic agents. Curr Anesth Crit Care 2004; 15:247–254.
Mert T, Gunes Y, Guven M, Gunay I, Ozcengiz D. Effects of calcium and magnesium on peripheral nerve conduction. Pol J Pharmacol 2003; 55:25–30.
Gunduz A, Bilir A, Gulec S. Magnesium added to prilocaine prolongs the duration of axillary plexus block. Reg Anesth Pain Med 2006; 31:233–236.
Haghighi M, Soleymanha M, Sedighinejad A, Mirbolook A, Naderi Nabi B, Rahmati M, Ashoori Saheli N. The effect of magnesium Sulphate on motor and sensory axillary plexus blockade. Anesth Pain Med 2015; 5:e21943.
Yangtse N, Shanmugavelu G, Jeyabaskaran A. Ultrasound guided supraclavicular brachial plexusblock with and without magnesium sulphate: a comparative study. J Evolution Med Dent Sci 2016; 5:2485–2489.
Ekmekci P, Bengisun ZK, Akan B, Kazbek BK, Ozkan KS, Suer AH. The effect of magnesium added to levobupivacaine for femoral nerve block on postoperative analgesia in patients undergoing ACL reconstruction. Knee Surg Sports Traumatol Arthrosc 2013; 21:1119–1124.
Choi IG, Choi YS, Kim YH, Min JH, Chae YK, Lee YK et al.
The effects of postoperative brachial plexus block using MgSO(4) on the postoperative pain after upper extremity Surgery. Korean J Pain 2011; 24:158–163.
Lee AR, Yi HW, Chung IS, Ko JS, Ahn HJ, Gwak MS et al.
Magnesium added to bupivacaine prolongs the duration of analgesia after interscalene nerve block. Can J Anaesth 2012; 59:21–27.
Myanroudi MH, Alizadeh K, Sadeghi M. Hypotension in spinal and epidural anesthesia. Bahrain Med Bull 2008; 30:1–5.
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[Table 1], [Table 2], [Table 3]