The Effects of Postoperative Brachial Plexus Block Using MgSO(4) on the Postoperative Pain after Upper Extremity Surgery

Efficacy of Ketamine versus Magnesium Sulphate as Adjuvants to Levobupivacaine in Ultrasound Bilevel Erector Spinae Block in Breast Cancer Surgery (a Double-Blinded Randomized Controlled Study)

Purpose

Breast surgeons seek simple, safe, effective, and novel regional anesthesia techniques for postoperative analgesia. Erector spinae plane (ESP) block is a new ultrasound-guided technique. We aimed to explore the analgesic effect of adding ketamine and magnesium sulfate as adjuvants to levobupivacaine in ESP.

Patients and Methods

Sixty female patients (aged 18-60 years) with breast cancer, weighing 50-90 kg who were scheduled for modified radical mastectomy (MRM) were randomly allocated into three groups (20 patients each) to receive an ESP block with 20 mL 0.25% levobupivacaine with adjuvants according to the following groups: group C: levobupivacaine; group K: levobupivacaine + 2 mg/kg ketamine; and group M: levobupivacaine + 2 mg/kg magnesium sulfate. The block was administered preoperatively before anesthesia induction. Postoperatively, hemodynamics, visual analog scale scores, the first request for analgesia, total analgesic consumption, and side effects were observed for 48 hours.

Results

The total amount of Morphine rescue analgesia was significantly lower in groups M (7.00 ± 0.61 mg) and K (7.50 ± 0.58 mg) than in group C (14.40 ± 3.47 mg) during the first 48 h postoperatively. Nine (45%) patients in group M and 13 (65%) patients in K, compared with 20 (100%) patients in group C, requested analgesia. The time to first request of analgesia was significantly longer in groups M (30 h) and K (24 h) than in group C (7 h). No hemodynamic changes or serious side effects were observed.

Conclusion

Magnesium sulphate and ketamine seem to be both effective adjuvants to levobupivacaine in ESP blocks for postoperative analgesia in patients undergoing MRM, with slightly better analgesia provided by magnesium sulphate.

Adductor Canal Blocks With Bupivacaine and Magnesium After Same-day Discharge Total Knee Arthroplasty Improve Postoperative Pain Relief and Decrease Opioid Consumption: A Prospective Randomized Controlled Trial

OBJECTIVES

Adequate pain management is a critical component of facilitating same-day discharge for total knee arthroplasty (TKA). Adductor canal blocks (ACB) have been shown to be an effective technique for managing pain after TKA. The objective of this study was to investigate the impact of adding magnesium to local anesthetic in ACB on postoperative pain, opioid consumption, nausea, and overall patient satisfaction.

MATERIALS AND METHODS

A sample of 119 adults undergoing elective unilateral TKA were included. Patients were randomly assigned to receive ACB with magnesium and bupivacaine (n=56) or with bupivacaine only (n=63). Primary outcomes were total opioid consumption in the first 48 hours after surgery and pain scores. Secondary outcomes were the incidence of nausea in the first 48 hours after surgery and total overall satisfaction.

RESULTS

Opioid consumption decreased significantly in the Mg group compared with the no-Mg group over the first 24 hours (33.2±3.0 vs. 21.3±2.4, P=0.003), the second 24 hours (35.4±2.7 vs. 27.3±2.3, P=0.026), and the first 48 hours total after surgery (68.6±5.1 vs. 48.6±4.3, P=0.004). Pain scores were reduced in the Mg group (24 h: 5.1±2.3 vs. 3.5±2.0, P=0.000; 48 h: 5.1±1.6 vs. 3.9±1.6, P=0.000). Secondary outcomes showed no difference in the incidence of nausea over the first 48 hours and overall satisfaction.

CONCLUSION

The addition of magnesium to local anesthetic in ACB decreases pain scores and opioid consumption, without increasing nausea, when compared with ACB with local anesthetic alone.

The Use of Magnesium Sulfate and Peripheral Nerve Blocks: An Updated Meta-analysis and Systematic Review

OBJECTIVES

With the popularization of ultrasound, nerve blocks have been widely implemented in current clinical practice. Although, they have seen limited success due to their shorter duration and suboptimal analgesia. Magnesium sulfate as a local anesthetic adjuvant for peripheral nerve blocks could enhance the effects of local anesthetics. However, previous investigations have not thoroughly investigated the analgesic efficacy of magnesium sulfate as an adjunct to local anesthetics for peripheral nerve blocks. Thus, we attempted to fill the gap in the existing literature by conducting a meta-analysis.

MATERIALS AND METHODS

We performed of a quantitative systematic review of randomized controlled trials published between May 30, 2011 and November 1, 2018. Inclusion criteria were: (1) magnesium sulfate used as adjuvant mixed with local anesthetic for nerve blockade, (2) complete articles and published abstracts of randomized controlled trials, (3) English language.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measures were time of onset, total duration of the sensory blockade, and Visual Analog Scale pain scores. The secondary outcomes were postoperative oral and intravenous analgesics consumption and the incidence of nausea and vomiting.

RESULTS

The 21 trials analyzed in this study included 1323 patients. Magnesium sulfate effectively prolonged the total duration of sensory blockade (mean difference [MD]=114.59 min, 95% confidence interval [CI]: 89.31-139.88), reducing Visual Analog Scale pain scores at 6 hours (MD=1.36 points, 95% CI: -2.09 to -0.63) and 12 hours (MD=1.54 points, 95% CI: -2.56 to -0.53) postsurgery. Magnesium sulfate also effectively reduced postoperative analgesic use within 24 hours postsurgery (standard MD=-2.06, 95% CI: -2.67 to -1.35). Furthermore, adjuvant magnesium sulfate significantly reduced the incidence of nausea and vomiting after transversus abdominis plane blockade (odds ratio: 0.39, 95% CI: 0.18-0.81).

CONCLUSION

Adjuvant magnesium sulfate enhanced the anesthetic effects of local anesthetics and improved postoperative analgesia following the perineural blockade.

Comparison of Magnesium Sulfate and Ketamine with Ropivacaine in Supraclavicular Brachial Plexus Block: A Randomized Controlled Trial

Background:

Supraclavicular brachial plexus block offers good operating conditions with limited postoperative analgesia. Magnesium sulfate (MgSO₄) and ketamine block peripheral nociception mediated via N-methyl-D-aspartate receptors.

Aims:

The aim of this study was to evaluate the effect of MgSO₄ and ketamine on the duration of analgesia in brachial block.

Settings and Design:

This was a prospective, randomized, controlled double-blind study.

Materials and Methods:

One hundred and five adult patients were randomly divided into three groups: Group I = 27 mL of 0.5% ropivacaine; Group II = 27 mL of 0.5% ropivacaine + 250 mg MgSO₄; and Group II = 27 mL of 0.5% ropivacaine + 2 mg.kg⁻¹ ketamine. Normal saline was added to make a total volume of 30 mL. The onset and duration of the sensorimotor blockade, quality and duration of postoperative analgesia, and adverse effects were assessed.

Statistical Analysis:

Statistical analysis was performed using SPSS, version 17.0 software (SPSS, Inc., Chicago, IL, USA). Chi-square test was used for nonparametric and ANOVA for parametric data. Post hoc Student's paired t-test was applied wherever indicated. The results were expressed as mean and standard deviation or numbers (%). P < 0.05 was considered as statistically significant.

Results:

The duration of analgesia was significantly longer in Group II (8.78 ± 0.97 h) compared to Group I (6.76 ± 0.92 h; P < 0.001) and Group III (7.1 ± 0.89 h; P < 0.001). Intervention groups had lower postoperative visual analog scores at 8, 12, and 24 h compared to the control group. Sedation, nystagmus, and hallucinations were observed in Group III.

Conclusion:

The addition of MgSO₄ to ropivacaine in supraclavicular brachial plexus block significantly prolongs the duration of analgesia. MgSO₄ improves the quality of postoperative analgesia with lesser incidence of side effects when compared to ketamine.

Evaluation of magnesium as an adjuvant to ropivacaine-induced axillary brachial plexus block: A prospective, randomised, double-blind study

Background and Aims:

Axillary brachial plexus block is commonly performed for surgeries on the hand and forearm. However, there are very few studies on the use of magnesium sulphate in axillary brachial plexus block and, hence, the study was designed to evaluate magnesium as an adjuvant to ropivacaine-induced axillary block with respect to onset and duration of sensorimotor block and postoperative analgesia.

Methods:

Sixty patients of the American Society of Anesthesiologists (ASA) physical status I and II, undergoing surgeries on the hand and forearm were randomly recruited to receive ultrasound-guided axillary block with either 150 mg magnesium sulphate or 1 mL normal saline added to 0.5% ropivacaine. The primary outcome measure was to compare block characteristics including postoperative analgesia and the secondary outcome was to compare the use of rescue analgesia and the side-effect profile. Data were statistically analysed using Statistical Package for Social Sciences (SPSS version 21.0). Categorical variables were compared using the Chi-square test or Fisher's exact probability test; continuous variables compared using unpaired t-test or Mann-Whitney U test.

Results:

Onset of sensory (9.93 ± 1.31 vs 8.83 ± 1.12 min) as well as motor block (13.37 ± 1.63 vs 11.57 ± 1.30 min) was significantly hastened with addition of magnesium to ropivacaine (p < 0.001) and so was the duration (sensory 386.60 ± 18.26 vs 526.37 ± 27.43, motor 323.73 ± 15.17 vs 436.97 ± 18.99 min) (p < 0.001) and postoperative analgesia (425 ± 21.39 vs 572.83 ± 32.04 min) (p < 0.001) which reflected in decreased requirement of rescue analgesic and total postoperative analgesic dosage.

Conclusions:

Magnesium is an effective and safe adjuvant to local anaesthetics and improves all characteristics of axillary brachial plexus block along with postoperative analgesia.

The use of intravenous magnesium sulfate on postoperative analgesia in orthopedic surgery: A systematic review of randomized controlled trials

INTRODUCTION

The aim of this systematic review is to investigate the effects of perioperative intravenous administration of MgSO4 on postoperative pain, analgesic consumption and adverse effects in patients undergoing orthopedic surgery.

METHODS

Two investigators independently searched for articles on randomized controlled trials (RCTs) from 1998 to 2016 in Pubmed, Web of science and Google scholar. We evaluated clinical outcomes, comparing postoperative pain scores, cumulative analgesic consumption, time to first analgesia, and adverse effects between orthopedic surgery patients with and without the administration of MgSO4.

RESULTS

After screening 2350 articles, 11 RCTs (with a total sample size of 535 subjects) were included in this systematic review. Perioperative intravenous administered MgSO4 could reduce postoperative pain intensity compared with control in 6 trials (55%), but without significant difference in 5 trials (45%). With MgSO4 treatments, postoperative analgesic consumption was significantly reduced in 8 trials (73%), and without significant difference in 2 trials (18%). Two trials evaluated the time to first request of analgesic after surgery and showed prolong of 2.3 hours and 93 minutes respectively. MgSO4 group had less postoperative nausea (relative risk [RR] = 0.32, 95% confidence interval [CI] = 0.12-0.82, number needed to harm [NNH] = 8.8), vomiting (RR = 0.38, 95% CI = 0.15-0.92, NNH = 9.7), and shivering (RR = 0.31, 95% CI = 0.11-0.88, NNH = 5.2).

CONCLUSION

Perioperative intravenous administration of MgSO4 in orthopedic surgery could reduce postoperative analgesic consumption and adverse effects such as vomiting, nausea, and shivering. These trials do not provide convincing evidence of beneficial effects on postoperative pain intensity and the time to first analgesic request. More trials should be conducted for the roles of MgSO4 in pain management for orthopedic surgery. However, intravenous MgSO4 administration should be considered as a strategy to relieve postoperative pain in orthopedic surgery patients.

Comparison of Magnesium Sulfate and Dexmedetomidine as an Adjuvant to 0.5% Ropivacaine in Infraclavicular Brachial Plexus Block

Background:

Magnesium sulfate and dexmedetomidine were used as adjuvants to local anesthesia to improve the quality of regional anesthesia.

Aims:

The aim of this study is to evaluate and compare the effects of magnesium sulfate and dexmedetomidine when added to ropivacaine on the quality of infraclavicular brachial plexus block (BPB).

Settings and Design:

This was a prospective randomized double-blinded controlled study.

Patients and Methods:

A total of 105 adult patients undergoing surgery in hands, wrist, and forearm using infraclavicular BPB were randomly assigned into three groups. Ultrasound-guided infraclavicular BPB was performed using 35 ml ropivacaine 0.5% diluted with 4 ml normal saline 0.9%. Magnesium sulfate 150 mg and dexmedetomidine 100 μg were added in the magnesium sulfate group and dexmedetomidine group, respectively. Duration of analgesia, onset times and durations of sensory block (SB) and motor block (MB), patient's satisfaction, and complications were recorded.

Statistical Analysis:

Statistical software SPSS 16 was used for statistical analysis.

Results:

Dexmedetomidine and magnesium sulfate provided longer duration of analgesia and lesser consumption of postoperative rescue analgesia than the control group (P = 0. 000); dexmedetomidine provided the longest duration of analgesia versus control and magnesium sulfate groups (P = 0.000). Dexmedetomidine provided the quickest onset times and the longest durations of both SB and MB than control and magnesium sulfate groups (P = 0.000). Dexmedetomidine group had higher incidences of bradycardia and hypotension.

Conclusions:

Magnesium sulfate or dexmedetomidine is a useful adjuvant to ropivacaine for infraclavicular BPB in lengthening the duration of analgesia. Dexmedetomidine provided quicker onset and longer duration of both SB and MB and longer duration of analgesia with lesser consumption of postoperative rescue analgesia; however, it showed a higher incidence of intraoperative hypotension and bradycardia than magnesium sulfate.

Adding magnesium sulfate to bupivacaine in transversus abdominis plane block for laparoscopic cholecystectomy: A single blinded randomized controlled trial

INTRODUCTION AND AIM

Use of transversus abdominis plane block (TAP) in the management of postoperative pain after the laparoscopic cholecystectomy (LC) has been a common anesthetic practice. This study evaluates the effect of adding magnesium sulfate to bupivacaine in TAP block in LC regarding postoperative analgesia and analgesic consumption.

PATIENTS AND METHODS

Ninety patients of American Society of Anesthesiologists I and II was divided into three groups: Control group (C group, n = 30), bupivacaine group (B group, n = 30), bupivacaine magnesium group (M group, n = 30).

RESULTS

M group showed better analgesic profile in the 1(st) postoperative day in the form of lower mean visual analog scale score (2.8 ± 0.6 for C group, 2.1 ± 0.5 for B group, 2.2 ± 0.5 for M group, P < 0.001), longer duration of analgesia (7 ± 2.8 h for C group, 16 ± 2.5 h for B group, 19 ± 2.2 h for M group, P < 0.006), lower morphine consumption (2 ± 0.1 mg for C group, 0.9 ± 0.1 mg for B group, 0.5 ± 0.1 mg for M group, P < 0.011). There was a significant lower incidence of postoperative nausea and vomiting (PONV) (32% for C group, 6% B group, 7% M group, P < 0.004).

CONCLUSION

Adding MgSo4 as an adjuvant to bupivacaine in TAP block; during anesthesia for LC; improved postoperative analgesia in the form of increased duration, decreased analgesic requirements and PONV.

The effect of magnesium sulfate on motor and sensory axillary plexus blockade

Background:

Magnesium is a physiologic cation that blocks neuromuscular transmission and does not allow the nerve to be stimulated.

Objectives:

This study investigates the effect of adding magnesium sulfate to lidocaine to extend the duration of sensory and motor blocks of the axillary plexus in orthopedic surgeries of the upper extremities.

Patients and Methods:

This controlled randomized double-blind study was performed on patients who were candidates for orthopedic surgery of the upper extremities. A total of 60 patients between 18–60 years with ASA Class 1 or 2 participated in the study. One group received lidocaine (5 mg/kg) with magnesium sulfate 20% (3 mL) as the case group, while the second group received lidocaine (5 mg/kg) with normal saline (3 mL) as a placebo to block the axillary plexus using the trans-arterial technique. The duration of the sensory and motor block of the axillary plexus was monitored and evaluated using the pinprick and modified Bromage scale.

Results:

A total of 60 patients were included in the study with 30 patients having received lidocaine plus magnesium and the other 30 patients having received lidocaine plus normal saline. The mean sensory block duration in the case group was 248.83 ± 18.36 and in control group was 204.67 ± 22.62. The mean motor block duration in the case group was 207.0 ± 16.64 and in control group was 147.33 ± 21.52 (both P < 0.0001). The mean onset of sensory block in case group was 15.5 ± 3.79 and the onset block in control group was 10.33 ± 4.13 (P < 0.0001). The mean onset of motor block in case group was 20.66 ± 4.09 and the onset block in control group was 19.73 ± 26.18 (P < 0.848).

Conclusions:

The addition of magnesium sulfate to lidocaine increased the duration of motor and sensory axillary block in the upper extremities during surgeries when compared to the use of lidocaine alone.

Evaluation of Magnesium as an adjuvant in Ropivacaine-induced supraclavicular brachial plexus block: A prospective, double-blinded randomized controlled study

Objective:

Different additives have been used to prolong brachial plexus block. We evaluated the effect of adding magnesium sulfate to ropivacaine for supraclavicular brachial plexus blockade. The primary endpoints were the onset and duration of sensory and motor block and duration of analgesia.

Methods:

One hundred patients (25–55 years) posted for elective forearm and hand surgeries under supraclavicular brachial plexus block were divided into two equal groups (Groups RM and RN) in a randomized, double-blind fashion. In group RM (n = 50), 30 ml 0.5% ropivacaine plus 150 mg (in 1 ml 0.9% saline) magnesium sulfate and in group RN (n = 50), 30 ml 0.5% ropivacaine plus 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), hemodynamic variables, and side effects were recorded for each patient.

Findings:

Though with similar demographic profile and block (sensory and motor) onset time, the 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 RM (P = 0.026) than group RN. Postoperative VAS values at 24 h were significantly lower in group RM (P = 0.045). Intraoperative hemodynamics was comparable among two groups and no appreciable side effect was noted throughout the study period.

Conclusion:

It can be concluded from this study that adding magnesium sulfate to supraclavicular brachial plexus block may increase the sensory and motor block duration and time to first analgesic use, and decrease total analgesic needs, with no side effects.

Feasibility of Early and Repeated Low-dose Interscalene Brachial Plexus Block for Residual Pain in Acute Cervical Radiculopathy Treated with NSAIDS

Background

To improve residual pain management in acute cervical radiculopathy treated with NSAIDs, the feasibility of early and repeated low-dose interscalene brachial plexus block (IS-BPB) needs to be assessed.

Methods

This was a prospective study on patients receiving NSAIDs (loxoprofen) for cervical radiculopathy of ≤ 2-week onset. Pain was assessed using the visual analogue scale (VAS). A low-dose ultrasonography (USG)-guided IS-BPB (dexamethasone [1.65 mg; 0.5 ml] and mepivacaine [1%; 3.0 ml]) was performed at baseline and weekly thereafter for 4 weeks in an outpatient setting for the intervention group. All patients were evaluated using a visual satisfaction score (VSS) at week 4. Patients with baseline VAS scores < 70 (mild to moderate pain; MM group) and ≥ 70 (severe pain; SE group) were compared to the controls receiving NSAIDs.

Results

A total of 316 IS-BPBs were performed in the intervention group. There was a significant difference in the decline in the VAS from week 0 to week 3 in the MM and SE groups (P < 0.05); however, from week 3 to week 4, the therapeutic effect exhibited no significant difference. Thirteen patients at week 2 (15.5%; MM: 27.7%; SE: 0%), 43 at week 3 (51.2%; MM: 83.0%; SE: 10.8%), and 47 at week 4 (56.0%; MM: 85.1%; SE: 18.9%) achieved a VAS score of ≤ 20. Patient satisfaction was high, and the decrease in VAS scores in both groups was significant (P < 0.05) compared to the controls.

Conclusions

Weekly, low-dose, USG-guided IS-BPB can be implemented for early pain relief in acute cervical radiculopathy, with high patient satisfaction.