Comparison of the effects of magnesium and ketamine on postoperative pain and morphine consumption. A double-blind randomized controlled clinical study

Unravelling the analgesic effects of perioperative magnesium in general abdominal surgery: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Prior research has established the effectiveness of magnesium in relieving postoperative pain. This article aims to evaluate magnesium sulfate for perioperative analgesia in adults undergoing general abdominal surgery under general anesthesia.

OBJECTIVE

The primary aim was to assess pain scores at 6 and 24 hours postoperatively in patients receiving magnesium sulfate vs. the control group. Secondary outcomes were postoperative opioid consumption, perioperative complications, and time to rescue analgesia.

METHODS

A comprehensive database search identified studies comparing magnesium sulfate with control in adults undergoing general anesthesia for general abdominal surgery. Using random-effects models, data were presented as mean ± Standard Deviation (SD) or Odds Ratios (OR) with corresponding 95% Confidence Intervals (95% CI). A two-sided p-value < 0.05 was considered statistically significant.

RESULTS

In total, 31 studies involving 1762 participants met the inclusion criteria. The magnesium group showed significantly lower postoperative pain scores at both early (within six hours) and late (up to 24 hours) time points compared to the control group. The early mean score was 3.1 ± 1.4 vs. 4.2 ± 2.3, and the late mean score was 2.3 ± 1.1 vs. 2.7 ± 1.5, resulting in an overall Mean Difference (MD) of -0.72; 95% CI -0.99, -0.44; p < 0.00001. The magnesium group was associated with lower rates of postoperative opioid consumption and shivering and had a longer time to first analgesia administration compared to the saline control group.

CONCLUSION

Magnesium sulfate administration was linked to reduced postoperative pain and opioid consumption following general abdominal surgery.

Interactions between Ketamine and Magnesium for the Treatment of Pain: Current State of the Art

BACKGROUND

Over the past three decades, NMDA-receptor antagonists have been shown to be efficient drugs for treating pain, particularly pain resistant to conventional analgesics. Emphasis will be on the old-new drugs, ketamine and magnesium, and their combination as a novel approach for treating chronic pain.

METHODS

The MEDLINE database was searched via PubMed for articles that were published up to March 1, 2020, with the keywords 'ketamine', 'magnesium', and 'pain' (in the title/abstract).

RESULTS

Studies in animals, as well as humans, have shown that interactions of ketamine and magnesium can be additive, antagonistic, and synergistic. These discrepancies might be due to differences in magnesium and ketamine dosage, administration times, and the chronological order of drug administration. Different kinds of pain can also be the source of divergent results.

CONCLUSION

This review explains why studies performed with a combination of ketamine and magnesium have given inconsistent results. Because of the lack of efficacy of drugs available for pain, ketamine and magnesium in combination provide a novel therapeutic approach that needs to be standardized with a suitable dosing regimen, including the chronological order of drug administration.

Opioid Use in the Postoperative Arena: Global Reduction in Opioids After Surgery Through Enhanced Recovery and Gynecologic Surgery

Enhanced recovery programs aim to reduce surgical stress to improve the patient perioperative experience. Through a combination of multimodal analgesia and maintaining a physiological state, postoperative recovery is improved. Many analgesic adjuncts are available that improve postoperative pain control and limit opioid analgesia requirements. Adjuncts are often used in combination, but different interventions may be incorporated for patient-specific and procedure-specific needs. Postoperative pain control can be optimized by continuing nonopioid adjuncts, and prescribing opioid analgesia to address breakthrough pain. Prescribing practices should balance optimizing pain relief, minimizing the risk of chronic pain, while limiting the potential for opioid misuse.

Perioperative intravenous ketamine for acute postoperative pain in adults

BACKGROUND

Inadequate pain management after surgery increases the risk of postoperative complications and may predispose for chronic postsurgical pain. Perioperative ketamine may enhance conventional analgesics in the acute postoperative setting.

OBJECTIVES

To evaluate the efficacy and safety of perioperative intravenous ketamine in adult patients when used for the treatment or prevention of acute pain following general anaesthesia.

SEARCH METHODS

We searched CENTRAL, MEDLINE and Embase to July 2018 and three trials registers (metaRegister of controlled trials, ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP)) together with reference checking, citation searching and contact with study authors to identify additional studies.

SELECTION CRITERIA

We sought randomised, double-blind, controlled trials of adults undergoing surgery under general anaesthesia and being treated with perioperative intravenous ketamine. Studies compared ketamine with placebo, or compared ketamine plus a basic analgesic, such as morphine or non-steroidal anti-inflammatory drug (NSAID), with a basic analgesic alone.

DATA COLLECTION AND ANALYSIS

Two review authors searched for studies, extracted efficacy and adverse event data, examined issues of study quality and potential bias, and performed analyses. Primary outcomes were opioid consumption and pain intensity at rest and during movement at 24 and 48 hours postoperatively. Secondary outcomes were time to first analgesic request, assessment of postoperative hyperalgesia, central nervous system (CNS) adverse effects, and postoperative nausea and vomiting. We assessed the evidence using GRADE and created a 'Summary of findings' table.

MAIN RESULTS

We included 130 studies with 8341 participants. Ketamine was given to 4588 participants and 3753 participants served as controls. Types of surgery included ear, nose or throat surgery, wisdom tooth extraction, thoracotomy, lumbar fusion surgery, microdiscectomy, hip joint replacement surgery, knee joint replacement surgery, anterior cruciate ligament repair, knee arthroscopy, mastectomy, haemorrhoidectomy, abdominal surgery, radical prostatectomy, thyroid surgery, elective caesarean section, and laparoscopic surgery. Racemic ketamine bolus doses were predominantly 0.25 mg to 1 mg, and infusions 2 to 5 µg/kg/minute; 10 studies used only S-ketamine and one only R-ketamine. Risk of bias was generally low or uncertain, except for study size; most had fewer than 50 participants per treatment arm, resulting in high heterogeneity, as expected, for most analyses. We did not stratify the main analysis by type of surgery or any other factor, such as dose or timing of ketamine administration, and used a non-stratified analysis.Perioperative intravenous ketamine reduced postoperative opioid consumption over 24 hours by 8 mg morphine equivalents (95% CI 6 to 9; 19% from 42 mg consumed by participants given placebo, moderate-quality evidence; 65 studies, 4004 participants). Over 48 hours, opioid consumption was 13 mg lower (95% CI 10 to 15; 19% from 67 mg with placebo, moderate-quality evidence; 37 studies, 2449 participants).Perioperative intravenous ketamine reduced pain at rest at 24 hours by 5/100 mm on a visual analogue scale (95% CI 4 to 7; 19% lower from 26/100 mm with placebo, high-quality evidence; 82 studies, 5004 participants), and at 48 hours by 5/100 mm (95% CI 3 to 7; 22% lower from 23/100 mm, high-quality evidence; 49 studies, 2962 participants). Pain during movement was reduced at 24 hours (6/100 mm, 14% lower from 42/100 mm, moderate-quality evidence; 29 studies, 1806 participants), and 48 hours (6/100 mm, 16% lower from 37 mm, low-quality evidence; 23 studies, 1353 participants).Results for primary outcomes were consistent when analysed by pain at rest or on movement, operation type, and timing of administration, or sensitivity to study size and pain intensity. No analysis by dose was possible. There was no difference when nitrous oxide was used. We downgraded the quality of the evidence once if numbers of participants were large but small-study effects were present, or twice if numbers were small and small-study effects likely but testing not possible.Ketamine increased the time for the first postoperative analgesic request by 54 minutes (95% CI 37 to 71 minutes), from a mean of 39 minutes with placebo (moderate-quality evidence; 31 studies, 1678 participants). Ketamine reduced the area of postoperative hyperalgesia by 7 cm² (95% CI -11.9 to -2.2), compared with placebo (very low-quality evidence; 7 studies 333 participants). We downgraded the quality of evidence because of small-study effects or because the number of participants was below 400.CNS adverse events occurred in 52 studies, while 53 studies reported of absence of CNS adverse events. Overall, 187/3614 (5%) participants receiving ketamine and 122/2924 (4%) receiving control treatment experienced an adverse event (RR 1.2, 95% CI 0.95 to 1.4; high-quality evidence; 105 studies, 6538 participants). Ketamine reduced postoperative nausea and vomiting from 27% with placebo to 23% with ketamine (RR 0.88, 95% CI 0.81 to 0.96; the number needed to treat to prevent one episode of postoperative nausea and vomiting with perioperative intravenous ketamine administration was 24 (95% CI 16 to 54; high-quality evidence; 95 studies, 5965 participants).

AUTHORS' CONCLUSIONS

Perioperative intravenous ketamine probably reduces postoperative analgesic consumption and pain intensity. Results were consistent in different operation types or timing of ketamine administration, with larger and smaller studies, and by higher and lower pain intensity. CNS adverse events were little different with ketamine or control. Perioperative intravenous ketamine probably reduces postoperative nausea and vomiting by a small extent, of arguable clinical relevance.

Comparison the analgesic effect of magnesium sulphate and Ketorolac in the treatment of renal colic patients: Double-blind clinical trial study

BACKGROUND

Ureter muscles contraction movements caused pain in renal colic. Magnesium sulphate could influence the pain by reducing acetylcholine in the nerve terminals. We have aimed to evaluate the analgesic effects of magnesium sulphate on acute renal colic pain.

METHOD

In this double-blind clinical trial study, the patients with renal colic pain were randomly divided into 2 groups; Group I received an intravenous infusion of 30 mg of Ketorolac and normal saline as placebo, Group II 50 mg/kg magnesium sulphate 50%/100 ml normal plus 30 mg of Ketorolac. The pain severity of patients was assessed using the visual analog scale (VAS) at baseline, and 15 and 30 min after intervention.

RESULTS

Baseline pain score and demographic characteristics did not significantly different between the groups. After 30 min the pain score significantly reduced in both groups. While, at 15 and 30 min, mean pain score did not show statistically significant differences.

CONCLUSION

Our findings indicated that Magnesium sulphate did not influence renal colic pain relief.

Comparing the efficacy of Morphine alone with Morphine and mgso4 in pain management after coronary artery bypass surgery

Objective:

To compare the effectiveness of Morphine alone and Morphine with MgSo4 in pain management after CABG surgery.

Methods:

This randomized control trial was conducted in the department of anesthesia and critical care Choudhary Pervaiz Ellahi Institute of Cardiology, Multan from November 2016 to June 2017. All collected data was entered and analyzed by using computer software SPSS version 23.1. Quantitative data like age, VAS score was analyzed and presented as mean and standard deviation. Similarly qualitative data like gender and ASA status was calculated and presented as frequency and percentages. Independent sample T-test was applied for significance of VAS score. P value ≤0.05 was considered as significant.

Results:

A total number of 150 patients of both genders were included in this study. The main outcome variables of our study were VAS score. It was observed that, in group (M), the mean VAS score after 4, 12 and 24 hours of operation was 5.24±1.61, 5.8±2.27 and 5.44±2.27 respectively. And in group (MM), the mean VAS score after 4, 12 and 24 hours of operation was 4.36±2.58, 3.48±2.10 and 4.12±1.05 respectively. It was noted that both groups had statically significant difference of VAS score, as group (M) had higher VAS score than group (MM).

Conclusion:

Morphine with Mgso4 has better efficacy as compared to morphine alone when used as analgesic agent after CABG surgery.

New Advances in Acute Postoperative Pain Management

PURPOSE OF REVIEW

Postoperative pain remains one of the most common challenges following inpatient and outpatient surgeries. With our advances in modern medicine, pain following surgical procedures still remains a challenge, though significant accomplishments have been made over the past few decades. This article highlights some of the promising new advances and approaches in postoperative pain management.

RECENT FINDINGS

Over the last decade, Enhanced Recovery after Surgery (ERAS) pathways and protocols are becoming the benchmark standards for enhancing postoperative recovery. Multimodal analgesia (MMA) is an essential component of such care. Further, in the wake of serious and persistent concern on the opioid epidemic in the USA, there has been a recent renewal of interest in non-opioid alternatives or adjuncts in controlling postoperative pain, often in the context of MMA. Intravenous (IV) acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), magnesium, ketamine, dexmedetomidine, liposomal bupivacaine, and newer neuraxial and peripheral regional techniques as well as patient-controlled modalities are gaining importance. Gabapentinoids have become popular but recent meta-analytic reviews have cast doubt on their routine use in perioperative settings. Among opioids, sublingual sufentanil, IV oxycodone, and iontophoretic transdermal fentanyl hold promise. Acupuncture and transcutaneous electrical nerve stimulation may be useful as adjuncts in MMA packages. Genetic testing, derivatives of herbal preparations, and an extended role of acute pain services may emerge as potential areas of importance in the future. There are, however, critical gaps in good quality evidence in many of the practice guideline recommendations. In the era of opioid epidemic, several lines of evidence have emerged to support non-opioid-based drugs and approaches along with a few newer opioid formulations for postoperative pain management, although more research is needed to find the right balance of efficacy and safety.

Sublingual, transdermal and intravenous patient-controlled analgesia for acute post-operative pain: systematic literature review and mixed treatment comparison

OBJECTIVE

To conduct a systematic literature review (SLR) and quantitative analysis to assess the comparative efficacy and safety of the sufentanil sublingual tablet system (SSTS) against other available patient controlled analgesia (PCA) options for post-operative analgesia.

METHODS

An SLR was conducted for studies published between 2004 and 2016. Due to study heterogeneity, subgroup analyses were conducted controlling for differences in imputation methods for missing values, baseline pain severity, and type of surgery. Where sufficient data was available, a mixed treatment comparison (MTC) was performed.

RESULTS

The MTC and subgroup analyses used 13 studies. In direct meta-analysis, there was a statistically significant difference in favor of SSTS compared with intravenous (IV) PCA (morphine) at 24 hours for the patient global assessment (PGA) scores of "good" or "excellent". For the Pain Intensity Score, there were numerical but not statistically significant differences in favor of the SSTS versus IV PCA (morphine) and the patient controlled transdermal system (PCTS) (fentanyl) in the MTC at 6 hours (standardized mean difference -0.27 [credible interval -2.78, 2.09] and -0.36 [-3.89, 3.03], respectively). The onset of pain relief was earlier with the SSTS versus IV PCA (morphine) as shown by the Pain Intensity Difference. Likewise, the onset was earlier compared with PCTS (fentanyl) where data was available. There was a significant difference in favor of SSTS compared with IV PCA (morphine) and with PCTS (fentanyl) for any adverse event, and numerical improvements for withdrawals due to adverse events.

CONCLUSIONS

This meta-analysis shows that SSTS is an option for non-invasive management of moderate-to-severe post-operative pain which can be more effective, faster in onset and better tolerated than IV PCA (morphine) and PCTS (fentanyl).