Magnesium and Ketamine Reduce Early Morphine Consumption After Open Bariatric Surgery: a Prospective Randomized Double-Blind Study

Intravenous Magnesium Sulfate as an Adjunct to Intravenous Ketamine for Acute Pain: A Case Series

Intravenous (IV) magnesium sulfate, a versatile electrolyte, plays a pivotal role across various medical domains. From cardiac care to obstetrics, gastrointestinal to pulmonary therapies, the impact is far-reaching among acute care services. Notably, in the postoperative phase of care, it shares intriguing similarities with ketamine as an NMDA receptor antagonist. This case series describes the difficulties experienced with postoperative analgesia in three patient cases with complex comorbidities and discusses the beneficial impact observed when magnesium was administered concomitantly with ketamine. Further research is necessary to outline the specific role, ideal population, and recommended bolus and infusion rate for optimal analgesic efficacy.

Efficacy of nonopioid analgesics and adjuvants in multimodal analgesia for reducing postoperative opioid consumption and complications in obesity: a systematic review and network meta-analysis

BACKGROUND

Managing postoperative pain in patients with obesity is challenging. Although multimodal analgesia has proved effective for pain relief, the specific impacts of different nonopioid i.v. analgesics and adjuvants on these patients are not well-defined. This study aims to assess the effectiveness of nonsteroidal antiinflammatory drugs, paracetamol, ketamine, α-2 adrenergic receptor agonists, lidocaine, magnesium, and oral gabapentinoids in reducing perioperative opioid consumption and, secondarily, in mitigating the occurrence of general and postoperative pulmonary complications (POPCs), nausea, vomiting, PACU length of stay (LOS), and hospital LOS among surgical patients with obesity.

METHODS

A systematic review and network meta-analysis was performed. PubMed, Scopus, Web of Science, CINAHL, and EMBASE were searched. Only English-language RCTs investigating the use of nonopioid analgesics and adjuvants in adult surgical patients with obesity were included. The quality of evidence and certainty were assessed using the RoB 2 tool and GRADE framework, respectively.

RESULTS

In total, 37 RCTs involving 3602 patients were included in the quantitative analysis. Compared with placebo/no intervention or a comparator, dexmedetomidine, ketamine, lidocaine, magnesium, and gabapentin significantly reduced postoperative opioid consumption after surgery. Ketamine/esketamine also significantly reduced POPCs. Ibuprofen, dexmedetomidine, and lidocaine significantly reduced postoperative nausea, whereas dexmedetomidine, either alone or combined with pregabalin, and lidocaine reduced postoperative vomiting. Dexmedetomidine significantly reduced PACU LOS, whereas both paracetamol and lidocaine reduced hospital LOS.

CONCLUSIONS

Intravenous nonopioid analgesics and adjuvants are crucial in multimodal anaesthesia, reducing opioid consumption and enhancing postoperative care in adult surgical patients with obesity.

SYSTEMATIC REVIEW PROTOCOL

CRD42023399373 (PROSPERO).

The Impact of Nutrition on Pain: A Narrative Review of Recent Literature

PURPOSE OF REVIEW

Pain is a complex phenomenon that affects millions of individuals worldwide and poses a significant burden on public health. While pain management typically focuses on pharmacological and physical interventions, emerging research suggests that nutrition plays a crucial role in pain modulation. This narrative review aims to explore the relationship between nutrition and pain, providing a comprehensive overview of recent literature. The review covers various dietary factors, including macronutrients, micronutrients, dietary patterns, and specific dietary interventions. Additionally, the potential mechanisms underlying the impact of nutrition on pain are discussed. The findings highlight the potential for dietary interventions to complement traditional pain management approaches and provide valuable insights for future research and clinical practice.

RECENT FINDINGS

Literature suggested the impact of healthy nutrition on improvement in pain and that certain types of food may increase and worsen different pain conditions. Nutrition plays an important role in modulating pain. It is important to counsel patients in pain on best diet for their pain condition to alleviate pain. Our article summarizes very well the issue of nutrition and pain and provides a guide to all practitioners caring for patients with chronic pain.

Non-Opioid Analgesics and Adjuvants after Surgery in Adults with Obesity: Systematic Review with Network Meta-Analysis of Randomized Controlled Trials

Background/Objectives: Managing postoperative pain in patients with obesity is challenging. Although using a combination of pain relief methods is recommended for these patients, the true effectiveness of various intravenous non-opioid analgesics and adjuvants in multimodal anesthesia needs to be better defined. Methods: A systematic review and network meta-analysis was performed to evaluate the efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen, ketamine, α-2 agonists, lidocaine, magnesium, and oral gabapentinoids in adult surgical patients with obesity. The analysis aimed to compare these treatments to a placebo/no treatment or alternative analgesics, with a primary focus on postoperative pain and secondary endpoints including rescue analgesia, postoperative nausea and vomiting (PONV), and recovery quality. English-language randomized controlled trials across PubMed, Scopus, Web of Science, CINAHL, and EMBASE were considered. Quality and evidence certainty were assessed with the RoB 2 tool and GRADE, and data was analyzed with R software. Results: NSAIDs, along with acetaminophen, lidocaine, α-2 agonists, ketamine, and oral gabapentinoids, effectively reduce early postoperative pain. NSAIDs, particularly ibuprofen, as well as acetaminophen, ketamine, and lidocaine, also show benefits in later postoperative stages. Intravenous non-opioid analgesics and adjuvants show some degree of benefit in reducing PONV and the need for rescue analgesic therapy when using α-2 agonists alone or combined with oral gabapentinoids, notably decreasing the likelihood of PONV. Ketamine, lidocaine, and α-2 agonists are shown to enhance postoperative recovery and care quality. Conclusions: Intravenous non-opioid analgesics and adjuvants are valuable in multimodal anesthesia for pain management in adult surgical patients suffering from obesity.

Antinociceptive and adverse effects of morphine:ketamine mixtures in rats

Prescription opioids are the gold standard for treating moderate to severe pain despite their well-documented adverse effects. Of all prescription medications, opioids are abused most widely, and fatal overdoses have reached epidemic levels. One strategy for improving the margin of safety of opioids is combining them with non-opioid drugs to decrease the opioid dose needed for pain relief, thereby reducing adverse effects that occur with larger doses. The N-methyl-D-aspartate receptor antagonist ketamine has been used safely as an analgesic but only under a very limited range of conditions. The current studies characterized the antinociceptive, behavioral suppressant, and gastrointestinal effects of morphine and ketamine alone and in mixtures to determine their interaction in 24 adult male Sprague-Dawley rats (n = 8 per assay). Given alone, both morphine and ketamine produced antinociception, decreased responding for food, and reduced gastrointestinal transit (i.e. produced constipation). The effects of morphine:ketamine mixtures generally were additive, except for the antinociceptive effects of 1:1 mixtures for which the difference in slope (i.e. non-parallel shift) between the observed and predicted effects suggested synergy at smaller doses and additivity at larger doses. The potency of morphine to produce constipation was not enhanced by administration of morphine:ketamine mixtures with antinociceptive effects. The nature of the interaction between morphine and ketamine for adverse effects such as dependence, withdrawal, abuse, or respiratory depression remains unknown but also might be related to the ratio of each drug in mixtures. It will be important to identify conditions that produce the largest potential therapeutic window in humans.

Impact of Perioperative Ketamine on Postoperative Bariatric Surgery Opioid Use and Length of Stay

SETTINGS

Postoperative pain management is an ever-growing challenge with the rise of the opioid crisis. Ketamine is an NMDA channel blocker, considered an alternative to perioperative opioid use; small concentrations are safe. Objective: The primary objective of this study was to evaluate the impact of perioperative ketamine administration on postoperative opioid use and the length of hospital stay in bariatric patients.

METHODS

Four hundred (366) charts were retrospectively reviewed; of those, 187 received ketamine and were placed in the Ketamine group, 179 received standard-of-care pain management and were part of the No-Ketamine group. Data was collected using medical databases from July 2020 to January 2021.

RESULTS

A greater length of stay was recorded in the No-Ketamine group (45.67±20.6 hours) when compared with the Ketamine group (40.6±14.3 hours); P <0.05. The Ketamine group had a mean MME of 17.5±16.5 whereas the No-Ketamine had a mean MME of 22.3±17.7, P <0.05.

CONCLUSIONS

Ketamine may be a feasible alternative to reduce opioid use and hospital length of stay. We believe that ketamine can be an important contribution to ERABS pathways, being responsible for improved outcomes after bariatric/metabolic surgical procedures.

Implementation of a standardized multimodal pain regimen significantly reduces postoperative inpatient opioid utilization in patients undergoing bariatric surgery

BACKGROUND

Routine opioid use in surgical patients has received attention given the opioid epidemic and a renewed focus on the dangers and drawbacks of opioids in the postoperative setting. Little is known about opioid use in bariatric surgery, especially in the inpatient setting. We hypothesize that a standardized opioid-sparing protocol reduces postoperative inpatient opioid use in bariatric surgery patients.

METHODS

A retrospective cohort study was conducted of bariatric surgery patients at a single institution. From March to September 2019, a standardized intraoperative and postoperative opioid-sparing protocol was designed and implemented along with an educational program for patients regarding safe pain management. Inpatient opioid utilization in patients undergoing surgery in the preintervention phase between April and March 2019 was compared to patients from a postintervention phase of October 2019 to December 2020. Opioid utilization was measured in morphine milliequivalents (MME).

RESULTS

A total of 359 patients were included; 192 preintervention and 167 postintervention. Patients were similar demographically. For all patients, mean age was 44.1 years, mean BMI 49.2 kg/m2, and 80% were female. Laparoscopic sleeve gastrectomy was performed in 48%, laparoscopic gastric bypass in 34%, robotic sleeve gastrectomy in 17%, and robotic gastric bypass in 1%. In the postintervention phase inpatient opioid utilization was significantly lower [median 134.8 [79.0-240.8] MME preintervention vs. 61.5 [35.5-150.0] MME postintervention (p < 0.001)]. MME prescribed at discharge decreased from a median of 300 MME preintervention to 75 MME postintervention (p < 0.001). In the postintervention phase, 16% of patients did not receive an opioid prescription at discharge compared to 0% preintervention (p < 0.001). When examining by procedure, statistically significant reductions in opioid utilization were seen for each operation.

CONCLUSION

Implementation of a standardized intraoperative and postoperative multimodal pain regimen and educational program significantly reduces inpatient opioid utilization in patients undergoing bariatric surgery.

Anaesthetic Approach to Enhanced Recovery after Surgery for Kidney Transplantation: A Narrative Review

Enhanced recovery after surgery (ERAS) protocols are designed to reduce medical complications, the length of hospital stays (LoS), and healthcare costs. ERAS is considered safe and effective for kidney transplant (KTx) surgery. KTx recipients are often frail with multiple comorbidities. As these patients follow an extensive diagnostic pathway preoperatively, the ERAS protocol can ideally be implemented at this stage. Small singular changes in a long perioperative pathway can result in significant positive outcomes. We have investigated the current evidence for an ERAS pathway related to anaesthetic considerations in renal transplant surgery for adult recipients.

Ketamine as a component of multimodal analgesia for pain management in bariatric surgery: A systematic review and meta-analysis of randomized controlled trials

Introduction

Anaesthesia in morbidly obese people is challenging with a high dose of opioid consumption. This systematic review and meta-analysis of randomised controlled trials (RCTs) summaries evidence comparing ketamine to placebo for pain management after bariatric surgery.

Methods

We used PRISMA 2020 and AMSTAR 2 guidelines to conduct this study. The random-effects model was adopted using Review Manager Version 5.3 for pooled estimates.

Results

Seven RCTs published between 2009 and 2021 were eligible, including a total of 412 patients (202 patients in the ketamine group and 210 patients in the control group). In the ketamine group total opioid consumption during the first 24 h postoperatively was reduced (mean difference, MD = −5.89; 95% CI [-10.39, −1.38], p = 0.01), lower pain score at 4 h (MD = −0.81; 95% CI [-1.52, −0.10], p = 0.03), pain score at 8 h (MD = −1.00; 95% CI [-1.21, −0.79], p < 0.01), and shorter hospital stay (MD = −0.10; 95% CI [-0.20, −0.01], p = 0.03). There was no significant difference between the two groups regarding duration of anaesthesia (MD = −3.42; 95% CI [-8.62, 1.82], p = 0.20), or sedation score (MD = −0.02; 95% CI [-0.21, 0.17], p = 0.84). As concern the postoperative complications, risks of postoperative nausea and vomiting(OR = 0.75; 95% CI [0.27, 2.04], p = 0.56), hallucinations (OR = 5.47; 95% CI [0.26, 117.23], p = 0.28), dizziness (OR = 1.05; 95% CI [0.14, 7.78], p = 0.96), and euphoria (OR = 5.77; 95% CI [0.65, 51.52], p = 0.12) were not different between the two groups either.

Conclusion

Ketamine could be an effective and safe technique for pain management following bariatric surgery. It reduces opioid consumption, postoperative pain, and hospital stay.

RegistrationThis review was registered in PROSPERO (CRD42022296484).

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This study comparing ketamine infusion or bolus with placebo when used with morphine, paracetamol or tramadol for pain management following bariatric surgery demonstrated that:

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Ketamine was associated with lower opioid consumption during the 24 h postoperatively.

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Ketamine decreased VAS scores at H4 and H8, and shorten the hospital stay.

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Ketamine ensure a similar duration of anaesthesia, postoperative sedation scores, PONV, and postoperative complications rate (hallucinations, headache, euphoria and dizziness).

Anesthesia and Enhanced Recovery After Surgery in Bariatric Surgery

The Enhanced Recovery After Surgery Society published guidelines for bariatric surgery reviewing the evidence and providing specific care recommendations. These guidelines emphasize preoperative nutrition, multimodal analgesia, postoperative nausea and vomiting prophylaxis, anesthetic technique, nutrition, and mobilization. Several studies have since evaluated these pathways, showing them to be safe and effective at decreasing hospital length of stay and postoperative nausea and vomiting. This article emphasizes anesthetic management in the perioperative period and outlines future directions, including the application of Enhanced Recovery After Surgery principles in patients with extreme obesity, diabetes, and metabolic disease and standardization of the pathways to decrease heterogeneity.

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.

Patients with sleep-disordered breathing for bariatric surgery

The prevalence of patients with obesity continues to rise worldwide and has reached epidemic proportions. There is a strong correlation between obesity and sleep-disordered breathing (SDB), and, in particular, obstructive sleep apnea (OSA). OSA is often undiagnosed in the surgical population. Bariatric surgery has been recognized as an effective treatment option for both obesity and OSA. Laparoscopic bariatric procedures, particularly laparoscopic sleeve gastrectomy (LSG), have become the most frequently performed procedures. OSA has been identified as an independent risk factor for perioperative complications and failure to recognize and prepare for patients with OSA is a major cause of postoperative adverse events, suggesting that all patients undergoing bariatric surgery should be screened preoperatively for OSA. These patients should be treated with an opioid-sparing analgesic plan and continuous positive airway pressure (CPAP) perioperatively to minimize respiratory complications. With the number of bariatric surgical patients with SDB likely to continue rising, it is critical to understand the best practices to manage this patient population.

Impact of Intraoperative Ketamine on Postoperative Analgesic Requirement Following Bariatric Surgery: a Meta-analysis of Randomized Controlled Trials

This meta-analysis aimed at exploring the impact of intravenous ketamine on pain relief and analgesic consumption in patients undergoing bariatric surgery (BS). Literature searches identified nine eligible trials with 458 participants. Forest plot revealed a significantly lower pain score [mean difference (MD) =  - 1.06, p = 0.005; 390 patients) and morphine consumption (MD =  - 3.85 mg, p = 0.01; 212 patients) immediately after BS in patients with intravenous ketamine than in those without. In contrast, pooled analysis showed comparable pain score (p = 0.28), morphine consumption (p = 0.45) within 24 h, and risk of postoperative nausea/vomiting (p = 0.67) between the two groups. In conclusion, the meta-analysis demonstrated improvements in pain outcomes immediately after surgery through perioperative intravenous ketamine administration despite the absence of analgesic benefit in the late postoperative period and a positive impact on postoperative nausea/vomiting.

Ketamine for the Treatment of Chronic Pain: A Comprehensive Review

Background

Chronic pain significantly worsens the quality of life. Unlike neuropathic, musculoskeletal, postoperative pain, and cancer pain, chronic primary pain cannot be explained by an underlying disease or condition, making its treatment arduous.

Objectives

This manuscript intends to provide a comprehensive review of the use of ketamine as a treatment option for specific chronic pain conditions.

Study Design

A review article.

Setting

A review of the literature.

Methods

A search was done on PubMed for relevant articles.

Results

A comprehensive review of the current understanding of chronic pain and the treatment of specific chronic pain conditions with ketamine.

Limitations

Literature is scarce regarding the use of ketamine for the treatment of chronic pain.

Conclusion

First-line treatment for many chronic pain conditions includes NSAIDs, antidepressants, anticonvulsants, and opioids. However, these treatment methods are unsuccessful in a subset of patients. Ketamine has been explored in randomized controlled trials (RCTs) as an alternative treatment option, and it has been demonstrated to improve pain symptoms, patient satisfaction, and quality of life. Conditions highlighted in this review include neuropathic pain, fibromyalgia, complex regional pain syndrome (CRPS), phantom limb pain (PLP), cancer pain, and post-thoracotomy pain syndrome. This review will discuss conditions, such as neuropathic pain, fibromyalgia, complex regional pain syndrome, and more and ketamine's efficacy and its supplementary benefits in the chronic pain patient population. As the opioid crisis in the United States continues to persist, this review aims to understand better multimodal analgesia, which can improve how chronic pain is managed.

Analgesic efficacy of ketamine and magnesium after laparoscopic sleeve gastrectomy: A randomized, double-blind, placebo-controlled trial

Background Ketamine and magnesium are antagonists of the N-methyl-d-aspartate receptor, and are valuable adjuvants for multimodal analgesia and opioid sparing. Data are limited regarding the opioid sparing efficacy of the combined intraoperative application of these agents in laparoscopic bariatric surgery. The objective of this study was to compare the postoperative opioid sparing properties of a single intraoperative dose of ketamine versus a combination of single doses of ketamine and magnesium after laparoscopic gastric sleeve resection in bariatric patients. Methods One hundred and twenty- six patients were randomly assigned to receive single boluses of ketamine alone 0.5 mg kg^-1 IV (ketamine group); combined ketamine bolus of 0.5 mg kg^-1 IV and magnesium 2 g IV (ketamine and magnesium group); or placebo. Opioid consumption at 24 h (in morphine equivalents); pain at rest; postoperative nausea and vomiting impact score; sedation scores; and trends of transcutaneous carbon-di-oxide values were analysed. Results The median (inter-quartile range [range]) morphine consumption at 24 h were 32 (24-47 [4.8-91]) mg in the ketamine group, 37 (18-53 [1-144]) mg in the ketamine and magnesium group, and 26 (21-36 [5-89]) mg in the control group and were not significantly different between the groups. There were no differences for all other outcomes examined. Conclusion Combined single intraoperative bolus doses of ketamine and magnesium did not result in postoperative opioid sparing after laparoscopic gastric sleeve resection.

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.