Analgesic Potentials of Preoperative Oral Pregabalin, Intravenous Magnesium Sulfate, and their Combination in Acute Postthoracotomy Pain

Analgesic Effects of Preoperative Combination of Oral Pregabalin and Intravenous Magnesium Sulfate on Postoperative Pain in Patients Undergoing Posterolateral Spinal Fusion Surgery: A 4-arm, Randomized, Double-blind, Placebo-controlled Trial

BACKGROUND

Multimodal perioperative pain management including nonopioid analgesia is a major pillar of enhanced recovery after surgery programs. The aim of this study was to investigate the analgesic efficacy of the preoperative combination of 2 nonopioid drugs, oral pregabalin and intravenous magnesium sulfate, in patients undergoing posterolateral lumbar spinal fusion.

METHODS

This 4-arm, randomized, double-blind, placebo-controlled trial included 104 patients randomly allocated to receive: magnesium sulfate and pregabalin (MP), magnesium sulfate and oral placebo (M), 0.9% saline and oral pregabalin (P), and 0.9% saline and oral placebo (C). The study drugs were administered 1 hour preoperatively. The primary outcome was the cumulative morphine consumption on postoperative day 1. Secondary outcomes included visual analog scale scores for leg pain at rest and with movement, and postoperative nausea and vomiting (PONV) in the first 48 hours after surgery.

RESULTS

Cumulative morphine consumption on postoperative day 1 was lower in group MP (19.6±8.0 mg) compared with group M (32.6±9.5 mg; P <0.001), group P (28.9±9.4 mg; P =0.001), or group C (38.8±10.3 mg; P <0.001). Multiple linear regression demonstrated a significant association between group MP and cumulative morphine consumption (B=-5.4 [95% CI, -7.1, -3.7], P <0.001). Visual analog scale scores for leg pain at rest and with movement were lower in group MP compared with other groups ( P =0.006 and <0.001). The incidence of PONV was also lowest in group MP ( P =0.032).

CONCLUSIONS

Preoperative administration of oral pregabalin and intravenous magnesium sulfate resulted in reduced morphine consumption and greater analgesic effect than the use of each drug individually or placebo in patients undergoing posterolateral lumbar spinal fusion.

Effect of Intraoperative infusion Magnesium Sulfate Infusion on Postoperative Quality of Recovery in Patients Undergoing Total Knee Arthroplasty: A Prospective, Double-Blind, Randomized Controlled Trial

Background

Magnesium sulfate, an intravenous adjuvant, has recently attracted immense attention in multimodal analgesia. Previous studies confirmed the crucial role of magnesium sulfate in postoperative pain and nociceptive hypersensitivity. However, the effect of magnesium sulfate in multimodal analgesia on the quality of recovery (QoR) for elderly patients has not been thoroughly studied. Therefore, the present experiment aimed to investigate the effect of continuous intravenous magnesium sulfate on the quality of postoperative recovery in elderly patients undergoing total knee arthroplasty (TKA).

Patients and Methods

In this study, a total of 148 patients scheduled to undergo unilateral total knee arthroplasty were randomized into a magnesium sulfate group (Group M, n=68) and a control group (Group C, n=66) using a double-blind, randomized controlled trial. Before induction of anesthesia, Group M received intravenous magnesium sulfate (40 mg/kg) for 15 min, followed by a continuous infusion (15 mg/kg) until the end of the procedure. In the same manner, Group C received an infusion of the same amount of isotonic saline using the same method as the Group M.

Results

Compared with Group C, Group M had significantly better QoR-15 scores on postoperative day 1(POD1) than Group C (P <0.05). Analysis of the dimensions of QoR-15 scores indicated that Group M exhibited notably reduced levels of pain, and higher levels of emotional state and physical comfort than Group C (P <0.05). Furthermore, Group C had significantly higher numerical rating scale (NRS) scores at POD1 than Group M (P <0.05).

Conclusion

For elderly patients undergoing knee arthroplasty, magnesium sulfate can be used as an adjuvant in a multimodal analgesic regimen to reduce early postoperative pain and improve the quality of early postoperative recovery.

Is intravenous magnesium sulphate a suitable adjuvant in postoperative pain management? - A critical and systematic review of methodology in randomized controlled trials

A growing worldwide focus on opioid-free anaesthesia entails multimodal analgesic strategies involving non-opioids such as magnesium sulphate (MgSO4). Several systematic reviews have concluded there is beneficial analgesic effect of MgSO4 administration but do not take considerable heterogeneity among the studies into consideration. Medical literature published until June 2021 was searched in PubMed/Medline, Embase, Central and Web of Science: The final search yielded a total of 5,672 articles. We included only randomised controlled trials assessing the effect of intravenous MgSO4 on opioid consumption and acute postoperative pain when compared to either placebo or standardized analgesic treatment. The primary aim was to compare the homogeneity of essential variables and confounders. A post-hoc meta-analysis demonstrated a reduction in both postoperative morphine consumption (-6.12 mg) and pain score (-12.32 VAS points) in favour of the MgSO4-groups. Data for meta-analysis was missing from 19 studies (45%) on morphine consumption and 29 studies (69%) for pain score, the majority of which reports no effect for either morphine consumption or pain score. The calculated heterogeneity among the included studies was considerable for both outcomes; I 2=91% for morphine consumption and I 2=96% for pain score. Although we found a per se reduction in opioid consumption and pain score, methodological heterogeneity and clinical shortcomings of pre-, intra-, and post anaesthetic data precludes conclusions on clinical importance of intraoperative intravenous MgSO4. In addition, the reduction is likely less than what can be gained from using standardized analgesic treatment.

A Meta-Analysis Showing the Quantitative Evidence Base of Preemptive Pregabalin for Postoperative Pain from Cancer-Related Surgery

Background and Objectives: As an adjunct to postoperative multimodal analgesic regimens, pregabalin has been reported in reducing postoperative acute pain and opioid consumption. However, there is only a small amount of evidence for preemptive pregabalin in patients undergoing cancer-related surgery. This systematic review was conducted to integrate high-quality evidence to evaluate the preemptive analgesic effects of pregabalin in cancer-related surgery. Materials and Methods: Seven electronic databases were searched in a combination of subject terms and free words. Efficacy and safety of preemptive pregabalin on postoperative pain for cancer-related surgery were evaluated by assessing resting and dynamic pain scores postoperatively, cumulative morphine equivalent consumption, time to first analgesic request, hemodynamic parameters, and the safety indicators. Results: Thirteen trials were incorporated for quantitative synthesis. The pooled results showed administration of pregabalin preoperatively is clinically significant for improving resting (weighted mean difference (WMD), -1.53 cm; 95% CI, -2.30 to -0.77) and dynamic (WMD, -1.16 cm; 95% CI, -2.22 to -0.11) pain severity scores at 2 h postoperatively and prolonging time to first analgesic request (WMD, 2.28 h; 95% CI, 0.79 to 3.77) in cancer-related surgery. Preemptive pregabalin was also statistically effective in some other pain indicators but would increase the risk of pregabalin-related side effects after surgery. Conclusions: Our findings do not support the administration of pregabalin in doses larger than 300 mg when put in cancer-related surgery. Taken together, more high-quality research particularly focused on the optimal dosages and timing of pregabalin in cancer-related surgery is needed in the future to establish stronger evidence for therapeutic effects.

Perioperative Indications for Gabapentinoids in Pediatrics: A Narrative Review

In recent years, there has been increased interest in using gabapentinoids (gabapentin and pregabalin) as part of multimodal medication plans or enhanced recovery after surgery protocols to mitigate several perioperative clinical challenges. Outcomes explored in the context of using gabapentinoids perioperatively in children are variable and include acute complications of pain, anxiety, nausea and vomiting, and emergence agitation, as well as the long-term postoperative outcome of chronic postsurgical pain. This narrative review describes the current literature regarding perioperative use of gabapentinoids in pediatric patients and aims to describe the role of gabapentinoids in the perioperative setting for each specific indication.

Postoperative pain management in non-traumatic emergency general surgery: WSES-GAIS-SIAARTI-AAST guidelines

BACKGROUND

Non-traumatic emergency general surgery involves a heterogeneous population that may present with several underlying diseases. Timeous emergency surgical treatment should be supplemented with high-quality perioperative care, ideally performed by multidisciplinary teams trained to identify and handle complex postoperative courses. Uncontrolled or poorly controlled acute postoperative pain may result in significant complications. While pain management after elective surgery has been standardized in perioperative pathways, the traditional perioperative treatment of patients undergoing emergency surgery is often a haphazard practice. The present recommended pain management guidelines are for pain management after non-traumatic emergency surgical intervention. It is meant to provide clinicians a list of indications to prescribe the optimal analgesics even in the absence of a multidisciplinary pain team.

MATERIAL AND METHODS

An international expert panel discussed the different issues in subsequent rounds. Four international recognized scientific societies: World Society of Emergency Surgery (WSES), Global Alliance for Infection in Surgery (GAIS), Italian Society of Anesthesia, Analgesia Intensive Care (SIAARTI), and American Association for the Surgery of Trauma (AAST), endorsed the project and approved the final manuscript.

CONCLUSION

Dealing with acute postoperative pain in the emergency abdominal surgery setting is complex, requires special attention, and should be multidisciplinary. Several tools are available, and their combination is mandatory whenever is possible. Analgesic approach to the various situations and conditions should be patient based and tailored according to procedure, pathology, age, response, and available expertise. A better understanding of the patho-mechanisms of postoperative pain for short- and long-term outcomes is necessary to improve prophylactic and treatment strategies.

Management of pain using magnesium sulphate: A narrative review

Pain is one of the most complex and unpleasant sensory and emotional human experiences. Pain relief continues to be a major medical challenge. The application of systemic opioid and regional analgesia techniques has facilitated a decrease in the occurrence and gravity of pain. Magnesium has an evolving role in pain management. Magnesium sulphate (MgSO4), the pharmacological form of magnesium, is a physiological voltage-dependent blocker of N-methyl-D-aspartate (NMDA)-coupled channels. In terms of its antinociceptive role, magnesium blocks calcium influx, which inhibits central sensitization and decreases preexisting pain hypersensitivity. These properties have encouraged the research of magnesium as an adjuvant agent for intra- and post-operative analgesia. Moreover, the mentioned magnesium impacts are also detected in patients with neuropathic pain. Intravenous magnesium sulphate, followed by a balanced analgesia, decreases opioid consumption. This review has focused on the existing evidence concerning the role of magnesium sulphate in pain management in situations including neuropathic pain, postherpetic neuralgia, trigeminal neuralgia, migraine, and post-operative pain. Additional studies are required to improve the use of magnesium sulphate for pain to increase the quality of life of patients.

Intravenously injected lidocaine or magnesium improves the quality of early recovery after laparoscopic cholecystectomy: A randomised controlled trial

BACKGROUND

Previous data show that lidocaine or magnesium has unique characteristics of stress inhibition and antiinflammation.

OBJECTIVE

We aimed to observe the effects of lidocaine or magnesium on the quality of recovery (QoR) after laparoscopic cholecystectomy.

DESIGN

Single-centre, prospective, randomised, double-blind study.

SETTING

The Affiliated Hospital of Xuzhou Medical University from March 2019 to October 2019.

PATIENTS

One hundred and fourteen patients scheduled for laparoscopic cholecystectomy.

INTERVENTION

The enrolled patients were randomly divided into three groups. Lidocaine (group L), magnesium sulphate (group M) or 0.9% saline (group C) was administered intravenously 10 min before induction.

MAIN OUTCOME MEASURES

The quality of recovery 15 (QoR-15) score, the Hospital Anxiety and Depression Scale (HADS), and the Numerical Rating Scale (NRS) score were selected. The usage of propofol and remifentanil, haemodynamic parameters, anaesthesia recovery parameters and adverse events were also evaluated.

RESULTS

The QoR-15 scores for group L (132.0) and group M (134.0) were 6 and 8 points higher than that of group C (126.0) on POD1 (postoperative day 1) (adjP < 0.05). However, the decrease of QoR-15 in Group L is less than the minimal clinically important difference (8).The NRS scores on POD1 in group C 3, were higher than other two groups (adjP < 0.05). The dosage of remifentanil in group L was lower than other two groups (adjP < 0.05).The physical independence of group L and group M and physical comfort of group M were improved compared with group C.

CONCLUSION

The results show that magnesium sulphate improved the QoR through improving physical comfort and physical independence in patients after laparoscopic cholecystectomy. However, lidocaine had limited effects on QoR under current conditions.

TRIAL REGISTRATION

ChiCTR1800019092 (www.chictr.org.cn).

CLINICAL TRIAL NUMBER AND REGISTRY URL

The study was registered in the Chinese Clinical Trials Register (ChiCTR1800019092) https://www.chictr.org.cn.

The effect of intravenous magnesium on postoperative morphine consumption in noncardiac surgery: A systematic review and meta-analysis with trial sequential analysis

BACKGROUND

Several studies suggest that systemic magnesium reduces postoperative opioid consumption and the intensity of pain, but others report conflicting results. The efficacy and safety profile of intravenous magnesium in noncardiac surgery remain uncertain.

OBJECTIVES

The aim of this review was to investigate the effect of intravenous magnesium on the consumption of postoperative morphine in the first 24 h in adults undergoing noncardiac surgery.

DESIGN

Systematic review and meta-analysis with trial sequential analysis.

DATA SOURCES

MEDLINE, EMBASE, CENTRAL from their inception until January 2019.

ELIGIBILITY CRITERIA

All randomised clinical trials comparing intravenous magnesium versus placebo in noncardiac surgery were systematically searched in the databases. Observational studies, case reports, case series and nonsystematic reviews were excluded.

RESULTS

Fifty-one trials (n=3311) were included for quantitative meta-analysis. In comparison with placebo, postoperative morphine consumption at 24-h was significantly reduced in the magnesium group, with a mean difference [95% confidence interval (CI)] of -5.6 mg (-7.54 to -3.66, P < 0.001, I = 92%, level of evidence low). The trial sequential analysis for the effect of magnesium on postoperative morphine consumption was conclusive. Patients who received magnesium had a longer time to the first analgesia request [143 (103 to 183) min, P < 0.001, I = 99%, level of evidence low] and a lower incidence of shivering [0.26 (0.15 to 0.44), P < 0.001, I = 35%, level of evidence very low]. However, no significance differences were demonstrated in postoperative pain scores in the first 24 h (mean difference, 95% CI) -0.30 (-0.69 to 0.09, P = 0.13, I = 91%, level of evidence low), bradycardia (odds ratio, 95% CI) 1.13 (0.43 to 2.98, P = 0.80, I = 35%, level of evidence very low) and postoperative nausea and vomiting (odds ratio, 95% CI) 0.90 (0.67 to 1.22, P = 0.49, I = 25%, level of evidence moderate).

CONCLUSION

The current meta-analysis demonstrates that the use of intravenous magnesium as part of multimodal analgesia may reduce morphine consumption in the first 24 h after surgery and delay the time to the first request for analgesia in patients undergoing noncardiac surgery. However, the included studies were of low-quality with substantial heterogeneity.

TRIAL REGISTRATION

CRD42018086846.

Pulsed Ultrasound Remedies Post-thoracotomy Hypersensitivity and Increases Spinal Anti-inflammatory Cytokine in Rats

The purpose of the experiment was to study the effect of pulsed ultrasound (PUS) on post-thoracotomy pain and local tissue temperature and to correlate the findings with the alteration in spinal anti-inflammatory and pro-inflammatory cytokines. Mechanical sensitivity, subcutaneous temperature and spinal interleukin-10 (IL-10), IL-6 or tumor necrosis factor-alpha (TNF-α) expression were examined in a rat model of experimental post-thoracotomy pain. Group 1 received a sham surgery where thoracotomy was performed except for rib retraction. Group 2 underwent thoracotomy with rib retraction (TRR). Group 3 received the TRR procedure followed by PUS. Group 4 underwent the TRR procedure followed by only the massage with the ultrasound turned off. Compared with group 1 (sham), groups 2-4 showed a decrease in mechanical withdrawal thresholds on postoperative days (PODs) 10 and 11. On PODs 16, 23 and 30, group 3 (TRR+PUS-1) displayed an increase in mechanical withdrawal thresholds compared with groups 2 and 4. Subcutaneous and body temperatures in group 3 were not prominently different from group 1, group 2 (TRR only) or group 4 (TRR+PUS-0). Compared with group 2, group 3 had an increase in spinal IL-10 level on POD 30 and a decrease in spinal IL-6 or TNF-α expression on PODs 16 and 30. We concluded that mechanical hypersensitivity after TRR is postponed by PUS, and its effect continues for 3 wk. A PUS dose not increase local tissue temperature. The beneficial effect of PUS appears related to upregulation of spinal anti-inflammatory cytokine and downregulation of spinal pro-inflammatory cytokines.

Magnesium and Pain

In terms of antinociceptive action, the main mode of action of magnesium involves its antagonist action at the N-methyl-d-aspartate (NMDA) receptor, which prevents central sensitization and attenuates preexisting pain hypersensitivity. Given the pivotal function of NMDA receptors in pain transduction, magnesium has been investigated in a variety of pain conditions. The oral and parenteral administration of magnesium via the intravenous, intrathecal, or epidural route may alleviate pain and perioperative anesthetic and analgesic requirements. These beneficial effects of magnesium therapy have also been reported in patients with neuropathic pain, such as malignancy-related neurologic symptoms, diabetic neuropathy, postherpetic neuralgia, and chemotherapy-induced peripheral neuropathy. In addition, magnesium treatment is reportedly able to alleviate fibromyalgia, dysmenorrhea, headaches, and acute migraine attacks. Although magnesium plays an evolving role in pain management, better understanding of the mechanism underlying its antinociceptive action and additional clinical studies is required to clarify its role as an adjuvant analgesic.