Efficacy of perioperative pregabalin in acute and chronic post-operative pain after off-pump coronary artery bypass surgery: a randomized, double-blind placebo controlled trial

Perioperative Implementation of Low-Dose Pregabalin in an Enhanced Recovery After Cardiac Surgery Protocol: A Pre-Post Observational Study

OBJECTIVES

Determine the effect of low-dose pregabalin in the perioperative enhanced recovery after cardiac surgery protocol.

DESIGN

Pre-post observational study.

SETTING

Tertiary care hospital.

PARTICIPANTS

Patients undergoing off-pump coronary artery bypass graft procedures.

INTERVENTIONS

Pregabalin 75 mg BID for 48 hours postoperatively versus no pregabalin in a perioperative setting.

MEASUREMENTS AND MAIN RESULTS

Perioperative opioid use, pain scores, length of stay, time to extubation, and mortality were all measured. Descriptive data were presented as mean (SD), median (IQR), or N (%). Ordinal and continuous data used the t-test or Kruskal-Wallis test. Categorical data were compared between groups using the chi-square test or Fisher's exact test, as appropriate. Low-dose pregabalin administration (75 mg twice daily for 48 hours after surgery) was associated with a clinically significant reduction in opioid consumption on postoperative day 0 by 30.6%, with a median requirement of 318 (233, 397) morphine milligram equivalents (MME) in the pregabalin group compared with 458 (375, 526) MME in the control group (p < 0.001). There was no significant difference in pain scores between the groups with the exception at 0-to-12 hours, during which the pregabalin group had greater pain scores (median 3.32 [1.65, 4.36] v 2.0 [0, 3.25], p = 0.013) (Table 3). Moreover, there was no significant difference in pain scores on postoperative day 1 (p = 0.492), day 2 (p = 0.442), day 3 (p = 0.237), and day 4 (p = 0.649). The difference in average Richmond Agitation Sedation Score scores was also not statistically significant between groups at 12 hours (p = 0.954) and at 24 hours (p = 0.301). The pregabalin group had no increased incidence of adverse events or any significant differences in intensive care unit length of stay, time to extubation, or mortality.

CONCLUSIONS

In this evaluation of perioperative pregabalin administration for patients requiring cardiac surgery, pregabalin reduced postoperative opioid use, with significant reductions on postoperative day 0, and without any significant increase in adverse reactions. However, no differences in intensive care unit length of stay, time to extubation, or mortality were noted. The implementation of low-dose perioperative pregabalin within an Enhanced Recovery After Cardiac Surgery protocol may be effective at reducing postoperative opioid use in the immediate postoperative period, and may be safe with regard to adverse events. Ideal dosing strategies have not been determined; thus, further randomized control trials with an emphasis on limiting confounding factors need to be conducted.

Pain management and opioid stewardship in adult cardiac surgery: Joint consensus report of the PeriOperative Quality Initiative and the Enhanced Recovery After Surgery Cardiac Society

BACKGROUND

Opioid-based anesthesia and analgesia is a traditional component of perioperative care for the cardiac surgery patient. Growing enthusiasm for Enhanced Recovery Programs (ERPs) coupled with evidence of potential harm associated with high-dose opioids suggests that we reconsider the role of opioids in cardiac surgery.

METHODS

An interdisciplinary North American panel of experts, using a structured appraisal of the literature and a modified Delphi method, derived consensus recommendations for optimal pain management and opioid stewardship for cardiac surgery patients. Individual recommendations are graded based on the strength and level of evidence.

RESULTS

The panel addressed 4 main topics: the harms associated with historical opioid use, the benefits of more targeted opioid administration, the use of nonopioid medications and techniques, and patient and provider education. A key principle that emerged is that opioid stewardship should apply to all cardiac surgery patients, entailing judicious and targeted use of opioids to achieve optimal analgesia with the fewest potential side effects. The process resulted in the promulgation of 6 recommendations regarding pain management and opioid stewardship in cardiac surgery, focused on avoiding the use of high-dose opioids, as well as encouraging more widespread application of foundational aspects of ERPs, such as the use of multimodal nonopioid medications and regional anesthesia techniques, formal patient and provider education, and structured system-level opioid prescription practices.

CONCLUSIONS

Based on the available literature and expert consensus, there is an opportunity to optimize anesthesia and analgesia for cardiac surgery patients. Although additional research is needed to establish specific strategies, core principles of pain management and opioid stewardship apply to the cardiac surgery population.

Practice Advisory for Preoperative and Intraoperative Pain Management of Cardiac Surgical Patients: Part 2

Pain after cardiac surgery is of moderate to severe intensity, which increases postoperative distress and health care costs, and affects functional recovery. Opioids have been central agents in treating pain after cardiac surgery for decades. The use of multimodal analgesic strategies can promote effective postoperative pain control and help mitigate opioid exposure. This Practice Advisory is part of a series developed by the Society of Cardiovascular Anesthesiologists (SCA) Quality, Safety, and Leadership (QSL) Committee's Opioid Working Group. It is a systematic review of existing literature for various interventions related to the preoperative and intraoperative pain management of cardiac surgical patients. This Practice Advisory provides recommendations for providers caring for patients undergoing cardiac surgery. This entails developing customized pain management strategies for patients, including preoperative patient evaluation, pain management, and opioid use-focused education as well as perioperative use of multimodal analgesics and regional techniques for various cardiac surgical procedures. The literature related to this field is emerging, and future studies will provide additional guidance on ways to improve clinically meaningful patient outcomes.

Comparative Efficacy of Adjuvant Nonopioid Analgesia in Adult Cardiac Surgical Patients: A Network Meta-Analysis

OBJECTIVES

To compare the relative efficacy of adjuvant nonopioid analgesic regimens in adult cardiac surgical patients.

DESIGN

This frequentist, random-effects network meta-analysis (NMA) was prospectively registered on PROSPERO (CRD42021282913) and conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analyses for Network Meta-Analyses (PRISMA-NMA). The risk of bias (RoB) and confidence of evidence were assessed by RoB 2 and Confidence in Network Meta-Analysis, respectively. Relevant databases were searched from inception to October 9, 2021.

SETTING

A total of 124 (N = 26,257) randomized controlled trials were included, of which 110 were analyzed.

PARTICIPANTS

Trials enrolling adults (≥18 years of age) undergoing cardiac surgery that compared nonopioid analgesics against other nonopioid analgesics, placebo, or no additional treatment, as adjuvants to standard analgesic management, and reported at least 1 of the outcomes of interest.

MEASUREMENT AND MAIN RESULTS

Outcomes of interest included resting postoperative pain scores at 24 hours. Compared with standard care and/or placebo, pain scores were reduced significantly by 10 different regimens, including acetaminophen (N = 176; mean difference [MD] -0.66 points, 95% CI -1.16 to -0.15 points; high confidence), magnesium (N = 323; -0.05 points, 95% CI -0.07 to -0.02 points; high confidence), gabapentin (N = 96; MD -0.40 points, 95% CI -0.71 to -0.09; moderate confidence), and clonidine (N = 64; MD v0.38 points, 95% CI -0.73 to v0.04 points; moderate confidence). Indomethacin, diclofenac, magnesium, and gabapentin significantly reduced 24-hour opioid consumption. Four regimens significantly decreased the intensive care unit length of stay. Hydrocortisone, dexmedetomidine, and clonidine significantly decreased the duration of mechanical ventilation. Magnesium decreased, while methylprednisolone significantly increased, the risk of myocardial infarction.

CONCLUSIONS

Given the increasing emphasis on enhanced recovery after surgery(ERAS) protocols and the eventual goal of limiting opiate prescriptions postoperatively, the authors' data suggested far greater use of nonopioid adjuncts to minimize pain and enhance recovery following cardiac surgery.

The complications of opioid use during and post-intensive care admission: A narrative review

Opioids are a commonly administered analgesic medication in the intensive care unit, primarily to facilitate invasive mechanical ventilation. Consensus guidelines advocate for an opioid-first strategy for the management of acute pain in ventilated patients. As a result, these patients are potentially exposed to high opioid doses for prolonged periods, increasing the risk of adverse effects. Adverse effects relevant to these critically ill patients include delirium, intensive care unit-acquired infections, acute opioid tolerance, iatrogenic withdrawal syndrome, opioid-induced hyperalgesia, persistent opioid use, and chronic post-intensive care unit pain. Consequently, there is a challenge of optimising analgesia while minimising these adverse effects. This narrative review will discuss the characteristics of opioid use in the intensive care unit, outline the potential short-term and long-term adverse effects of opioid therapy in critically ill patients, and outline a multifaceted strategy for opioid minimisation.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered. Structure: Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The guideline for coronary artery revascularization replaces the 2011 coronary artery bypass graft surgery and the 2011 and 2015 percutaneous coronary intervention guidelines, providing a patient-centric approach to guide clinicians in the treatment of patients with significant coronary artery disease undergoing coronary revascularization as well as the supporting documentation to encourage their use.

METHODS

A comprehensive literature search was conducted from May 2019 to September 2019, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, CINHL Complete, and other relevant databases. Additional relevant studies, published through May 2021, were also considered.

STRUCTURE

Coronary artery disease remains a leading cause of morbidity and mortality globally. Coronary revascularization is an important therapeutic option when managing patients with coronary artery disease. The 2021 coronary artery revascularization guideline provides recommendations based on contemporary evidence for the treatment of these patients. The recommendations present an evidence-based approach to managing patients with coronary artery disease who are being considered for coronary revascularization, with the intent to improve quality of care and align with patients' interests.

Pain Management Considerations in Patients with Opioid Use Disorder Requiring Critical Care

The opioid epidemic has resulted in increased opioid-related critical care admissions, presenting challenges in acute pain management. Limited guidance exists in the management of critically ill patients with opioid use disorder (OUD). This narrative review provides the intensive care unit (ICU) clinician with guidance and treatment options, including non-opioid analgesia, for patients receiving medications for opioid use disorder (MOUD) and for patients actively misusing opioids. Verification and continuation of the patient's outpatient MOUD regimen, specifically buprenorphine and methadone formulations, assessment of pain and opioid withdrawal, and treatment of acute pain with non-opioid analgesia, nonpharmacologic strategies, and short-acting opioids as needed, are all essential to adequate management of acute pain in patients with OUD. A multidisciplinary approach to treatment and discharge planning in patients with OUD may be beneficial to engage patients with OUD early in their hospital stay to prevent withdrawal, stabilize their OUD, and to reduce the risk of unplanned discharge and other associated morbidity. This article is protected by copyright. All rights reserved.

The immunomodulatory effects of opioids and implications for intensive care unit populations

Analgesia within the intensive care unit (ICU) is often achieved via the utilization of opioids in alignment with current guidelines. Recent evidence has not only demonstrated the potential impact of opioids in suppression of immune function, but also the potential harm of immunosuppression of patients within the ICU. Despite the potential immunosuppression seen with opioids in this at-risk population, their use remains frequent. In this review, we highlight the potential immunomodulatory impact of opioids within the critically ill and considerations for their use.

Pharmacotherapy for the Prevention of Chronic Pain after Surgery in Adults: An Updated Systematic Review and Meta-analysis

BACKGROUND

Chronic postsurgical pain can severely impair patient health and quality of life. This systematic review update evaluated the effectiveness of systemic drugs to prevent chronic postsurgical pain.

METHODS

The authors included double-blind, placebo-controlled, randomized controlled trials including adults that evaluated perioperative systemic drugs. Studies that evaluated same drug(s) administered similarly were pooled. The primary outcome was the proportion reporting any pain at 3 or more months postsurgery.

RESULTS

The authors identified 70 new studies and 40 from 2013. Most evaluated ketamine, pregabalin, gabapentin, IV lidocaine, nonsteroidal anti-inflammatory drugs, and corticosteroids. Some meta-analyses showed statistically significant-but of unclear clinical relevance-reductions in chronic postsurgical pain prevalence after treatment with pregabalin, IV lidocaine, and nonsteroidal anti-inflammatory drugs. Meta-analyses with more than three studies and more than 500 participants showed no effect of ketamine on prevalence of any pain at 6 months when administered for 24 h or less (risk ratio, 0.62 [95% CI, 0.36 to 1.07]; prevalence, 0 to 88% ketamine; 0 to 94% placebo) or more than 24 h (risk ratio, 0.91 [95% CI, 0.74 to 1.12]; 6 to 71% ketamine; 5 to 78% placebo), no effect of pregabalin on prevalence of any pain at 3 months (risk ratio, 0.88 [95% CI, 0.70 to 1.10]; 4 to 88% pregabalin; 3 to 80% placebo) or 6 months (risk ratio, 0.78 [95% CI, 0.47 to 1.28]; 6 to 68% pregabalin; 4 to 69% placebo) when administered more than 24 h, and an effect of pregabalin on prevalence of moderate/severe pain at 3 months when administered more than 24 h (risk ratio, 0.47 [95% CI, 0.33 to 0.68]; 0 to 20% pregabalin; 4 to 34% placebo). However, the results should be interpreted with caution given small study sizes, variable surgical types, dosages, timing and method of outcome measurements in relation to the acute pain trajectory in question, and preoperative pain status.

CONCLUSIONS

Despite agreement that chronic postsurgical pain is an important topic, extremely little progress has been made since 2013, likely due to study designs being insufficient to address the complexities of this multifactorial problem.

EDITOR’S PERSPECTIVE

Nonopioid Analgesics in Postoperative Pain Management After Cardiac Surgery

Opioid analgesia is still considered the standard of practice for cardiac surgery. In recent years, combinations of several nonnarcotic analgesics and regional analgesia have shown promise in restricting opioid use during and after cardiac surgery. Ketamine infusion, dexmedetomidine infusion, acetaminophen, ketorolac, and gabapentin are useful adjuvants in cardiac anesthesia practice and have opioid-sparing properties. The beneficial effects of nonnarcotic multimodal analgesia on intraoperative stress response, recovery profile, postoperative pain, and persistent opioid use after cardiac surgery are yet to be established, and further randomized clinical trials are required.

Oral Pregabalin in Cardiac Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

Pregabalin has received wide clinical attention as a new type of analgesic. We undertake a systematic review and meta-analysis to evaluate the effect of pregabalin on postoperative pain in patients undergoing cardiac surgery.

Methods

We searched PubMed, Embase, and Cochrane Library (from inception to July 2020) for eligible studies. The primary outcomes were the total morphine consumption at 24 h. A secondary outcome was intraoperative fentanyl consumption, extubation time postoperative, and length of stay in hospital. We calculated pooled weighted mean difference (WMD) or odds ratio (OR) and 95% CIs using random- or fixed-effects models.

Results

Seven trials involving 463 patients were listed. Meta-analysis showed that the total morphine consumption at 24 h in the pregabalin group was significantly less than the control group (WMD: -5.44, 95% CI: -10.42–0.46, P = 0.03). We found that there is no significant difference between the two groups in intraoperative fentanyl consumption. Compared with the control group, the length of stay in hospital in the pregabalin group was significantly shorter (WMD = -0.87, 95% CI: -1.42−0.32, P = 0.002). And we found that there were no significant differences between the two groups in extubation time (WMD: 17.24, 95% CI: -24.36−58.84, P = 0.42).

Conclusions

Oral pregabalin for cardiac surgery patients can effectively reduce the patient's 24-hour morphine consumption after surgery, shorten the patient's hospital stay, and is more conducive to early postoperative recovery.

Elements not Graded in the Cardiac Enhanced Recovery After Surgery Guidelines Might Improve Postoperative Outcome: A Comprehensive Narrative Review

Enhanced Recovery Programs (ERPs) are protocols involving the whole patient surgical journey. These protocols are based on multimodal, multidisciplinary, evidence-based, and patient-centered approaches aimed at improving patient recovery after a surgical intervention. Such programs have shown striking positive results in different surgical specialties. However, only a few research groups have incorporated preoperative, intraoperative, and postoperative evidence-based interventions in bundles used to standardize care and build cardiac surgery ERPs. The Enhanced Recovery After Surgery Society recently published evidence-based recommendations for perioperative care in cardiac surgery. Their recommendations included 22 perioperative interventions that may be part of any cardiac ERP. However, various components integrated in already-published cardiac ERPs were neither graded nor reported in these recommendations. The goals of the current review are to present published cardiac ERPs and their effects on patient outcomes and reported components incorporated into these ERPs and to discuss the objectives and scope of cardiac ERPs.

Perioperative care in cardiac surgery

As mortality is now low for many cardiac surgical procedures, there has been an increasing focus on patient centered outcomes such as recovery and quality of life. The Enhanced Recovery After Surgery (ERAS) cardiac society recently published the first set of guidelines for cardiac surgery which will be useful as a starting point to help translate this philosophy for the benefit of those undergoing cardiac surgery. At the same time there are many advances in other areas such as mechanical circulation, diagnostics and quality metrics. We intend here to present a balanced and evidenced based review of selected aspects of current practice, encompassing both UK and international perioperative care with a focus on recent advances. For the convenience of the reader we will adopt the conventional perioperative preoperative, intraoperative and postoperative phases of care. The focus of cardiac surgical practice needs to evolve from mortality to recovery. Those specialists who work in cardiac anaesthesia and critical care are well placed to contribute to these changes. Accompanying this work is the development of technologies to improve recognition of and intervention to prevent early organ dysfunction. Measuring, benchmarking and publishing quality outcomes from cardiac surgical centres is likely to improve services and benefit our patients.

Reducing Opioid Use in Patients Undergoing Cardiac Surgery - Preoperative, Intraoperative, and Critical Care Strategies

Patients undergoing cardiothoracic surgery are exposed to opioids in the operating room and intensive care unit and after hospital discharge. Opportunities exist to reduce perioperative opioid use at all stages of care and include alternative oral and intravenous medications, novel intraoperative regional anesthetic techniques, and postoperative opioid-sparing sedative and analgesic strategies. In this review, currently used and investigational strategies to reduce the opioid burden for cardiothoracic surgical patients are explored.

The effect of preemptive use of pregabalin on postoperative morphine consumption and analgesia levels after laparoscopic colorectal surgery: a controlled randomized trial

PURPOSE

In order to reduce postoperative opioid administration and pain levels in patients submitted to laparoscopic colectomy, we assessed the efficacy of preemptive use of pregabalin (PG), as part of a multimodal analgesia scheme, in a randomized controlled trial setting.

METHODS

Overall, fifty adult patients scheduled for elective laparoscopic colectomy were included and randomized in our trial. In the experimental group, 23 patients received preoperatively 2 doses of 150 mg PG per os, whereas the control group consisted of 27 cases, where a matching to PG placebo was administered at the same scheme. The two groups had identical analgesia and anesthesia regimens otherwise. Our study endpoints included postoperative morphine consumption, postoperative pain, and complication rates.

RESULTS

Patients in the PG group displayed a significantly reduced morphine consumption at 8 h, 24 h, and 48 h postoperatively. The two groups were comparable in terms of postoperative pain (rest and movement assessment) and side effects.

CONCLUSIONS

The preoperative addition of PG resulted in a significant reduction of the postoperative opioid consumption in patients undergoing laparoscopic colectomy. However, an association with the postoperative pain scores was not identified.

Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU

OBJECTIVE

To update and expand the 2013 Clinical Practice Guidelines for the Management of Pain, Agitation, and Delirium in Adult Patients in the ICU.

DESIGN

Thirty-two international experts, four methodologists, and four critical illness survivors met virtually at least monthly. All section groups gathered face-to-face at annual Society of Critical Care Medicine congresses; virtual connections included those unable to attend. A formal conflict of interest policy was developed a priori and enforced throughout the process. Teleconferences and electronic discussions among subgroups and whole panel were part of the guidelines' development. A general content review was completed face-to-face by all panel members in January 2017.

METHODS

Content experts, methodologists, and ICU survivors were represented in each of the five sections of the guidelines: Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption). Each section created Population, Intervention, Comparison, and Outcome, and nonactionable, descriptive questions based on perceived clinical relevance. The guideline group then voted their ranking, and patients prioritized their importance. For each Population, Intervention, Comparison, and Outcome question, sections searched the best available evidence, determined its quality, and formulated recommendations as "strong," "conditional," or "good" practice statements based on Grading of Recommendations Assessment, Development and Evaluation principles. In addition, evidence gaps and clinical caveats were explicitly identified.

RESULTS

The Pain, Agitation/Sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) panel issued 37 recommendations (three strong and 34 conditional), two good practice statements, and 32 ungraded, nonactionable statements. Three questions from the patient-centered prioritized question list remained without recommendation.

CONCLUSIONS

We found substantial agreement among a large, interdisciplinary cohort of international experts regarding evidence supporting recommendations, and the remaining literature gaps in the assessment, prevention, and treatment of Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) in critically ill adults. Highlighting this evidence and the research needs will improve Pain, Agitation/sedation, Delirium, Immobility (mobilization/rehabilitation), and Sleep (disruption) management and provide the foundation for improved outcomes and science in this vulnerable population.

Non-opioid analgesics as adjuvants to opioid for pain management in adult patients in the ICU: A systematic review and meta-analysis

PURPOSE

To identify the impact of non-opioid analgesics as adjuvants to opioid on opioid consumption and its side effects, as well as the analgesic effectiveness in adult patients in the ICU.

METHODS

Only randomized clinical trials using non-opioid analgesics for analgesia in the ICU were included. Pooled analyses with 95% CI were determined.

RESULTS

Twelve studies (mainly surgical and Guillain-Barre syndrome patients) were included. Non-opioid analgesics as adjuvants to opioid were associated with a significant reduction in the consumption of opioids when compared with opioid use alone at Day 1 (MD -15.40; 95% CI -22.41 to -8.39; P < .001) and Day 2 (MD -22.93; 95% CI -27.70 to -18.16; P < .001). Non-opioid analgesics as adjuvants to opioid were associated with a significantly lower incidence of nausea and vomiting when compared with opioid use alone (RR 0.46; 95% CI 0.30 to 0.68; P < .001). Non-opioid analgesics as adjuvants to opioid significantly decreased the pain score at Day 1 (MD -0.68; 95% CI -1.28 to -0.08; P = .03) and Day 2 (MD -1.36; 95% CI -2.47 to -0.24; P = .02).

CONCLUSIONS

Non-opioid analgesics as adjuvants to opioid reduced the consumption and the side effects of opioids in adult surgical and Guillain-Barre syndrome patients in the ICU.

TRIAL REVIEW REGISTRATION

PROSPERO international prospective register of systematic reviews on January 23, 2017, registration number CRD42017055768.

Beyond Opioids for Pain Management in Adult Critically Ill Patients

Critically ill patients commonly experience pain, and the provision of analgesia is an essential component of intensive care unit (ICU) care. Opioids are the mainstay of pain management in the ICU but are limited by their adverse effects, risk of addiction and abuse, and recent drug shortages of injectable formulations. A multimodal analgesia approach, utilizing nonopioid analgesics as adjuncts to opioid therapy, is recommended since they may modulate the pain response and reduce opioid requirements by acting on multiple pain mediators. Nonopioid analgesics discussed in detail in this article are acetaminophen, α-2 receptor agonists, gabapentinoids, ketamine, lidocaine, and nonsteroidal anti-inflammatory drugs. This literature review describes the clinical pharmacology, supportive ICU and relevant non-ICU data, and practical considerations associated with the administration of nonopioid analgesics in critically ill adult patients.

Optimising pain management protocols following cardiac surgery: A protocol for a national quality improvement study

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Severe pain is associated with tachyarrhythmias, shallow breathing and poor recovery.

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Our protocol was effective at reducing post-cardiac surgery pain in a single centre.

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It consists of pre-operative gabapentin and dividing patients based on risk of pain.

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High-risk group receive PCA along with paracetamol and codeine given to all patients.

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Centres will undertake a baseline audit, then implement a protocol and re-audit pain.

Pain following cardiac surgery is a multifaceted phenomenon resulting from a number of mechanisms. High-levels of post-operative pain are associated with cardiovascular and respiratory complications and adequate pain management is crucial for enabling fast recovery. However, adequate pain control is complex, a challenge that stems from a combination of poor reporting of pain, significant variation amongst patients and the side-effects of strong, particularly opioid, analgesics. An initial audit at our hospital demonstrated high-levels of post-operative pain following cardiac surgery and a protocol was therefore devised by the anaesthetic department for cardiac surgical pain management. The protocol stratified patients into high- or low-risk of pain based on the presence of risk factors for pain and utilised a combination of pre-operative one-off dose of gabapentin, intra-operative opioid infusion and post-operative multimodal analgesia with paracetamol, weak and strong opioids. Additionally, patients at high-risk of pain also received patient controlled analgesia. Use of this protocol was associated with improved pain scores on the first three post-operative days. We have devised this study to test for reproducibility of the benefit experienced at our hospital at a larger multicentre level. After acquiring pre-existing post-operative pain management strategies through an initial survey, local study leads will undertake a baseline audit. Local study leads will then lead a 4-week period of protocol implementation. Trusts with official pain management protocols will be given the option to re-circulate their pre-existing protocols. Subsequently, pain scores during post-operative days 1–3 will be re-audited.

Non-Hormonal Replacement Therapy Regimens: Do they have an Effect on Cardiovascular Risk?

INTRODUCTION

Menopause is associated with adverse effects on quality of life of perimenopausal and post-menopausal women. It also has an impact on the development of cardiovascular disease (CVD). Hormonal treatments are the most effective medications for menopausal symptoms relief. Given the fact that hormonal treatments are contraindicated for many women, non-hormonal treatment, such as Selective Serotonin Reuptake Inhibitors (SSRIs), Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs), gabapentin, pregabalin, clonidine and phytoestrogens, constitute alternative treatments. Nevertheless, little is known about their effects on CVD risk.

METHODS

PubMed, EMBASE and Cochrane Library were searched for the effects of non-hormonal treatment on CVD risk, blood pressure, heart rate, lipids and glucose concentrations, weight gain, cardiovascular events, stroke, mortality and morbidity.

RESULTS

Phytoestrogens, pregabalin and gabapentin seem to have no adverse effects on the cardiovascular system. Phytoestrogens, in particular, seem to reduce CVD risk through many pathways. On the other hand, SSRIs and SNRIs, although effective in reducing menopausal vasomotor symptoms, should be cautiously administered to women with known CVD (e.g. with cardiac arrhythmias, atherosclerotic disease or stroke). As clonidine has been associated with cardiovascular adverse effects, it should be administered only in cases where blood pressure regulation is mandatory.

CONCLUSION

Further research is needed to produce definite conclusions regarding the cardiovascular safety of non-hormonal medications for menopausal symptoms relief.

The effect of pre-emptive gabapentin on anaesthetic and analgesic requirements in patients undergoing rhinoplasty: A prospective randomised study

Background and Aims:

Hypotensive anaesthesia is necessary in rhinoplasty for better visualisation of surgical field and reduction of surgery time. Gabapentin is a new generation anticonvulsant with anti-hyperalgesic and anti-nociceptive properties. We aimed to investigate the effect of pre-operative administration of oral gabapentin (1200 mg) on anaesthetic requirements and post-operative analgesic consumption and its role in hypotensive anaesthesia for rhinoplasty.

Methods:

Seventy adult patients undergoing rhinoplasty, were randomly allocated to two groups. Group I (G I) (n = 35) received gabapentin 1.2 g and Group II (G II) (n = 35) received oral placebo capsules 2 h before surgery. General anaesthesia was maintained with sevoflurane in oxygen-nitrous oxide to maintain bispectral index value between 40 and 60, and remifentanil infusion to keep mean arterial pressure (MAP) at 55–60 mmHg. End-tidal sevoflurane concentration, intra-operative remifentanil consumption and time to intended MAP were recorded. Visual analogue scale (VAS) scores, post-operative analgesic requirements and side effects for the first 24 h were recorded.

Results:

G I required significantly lower intra-operative remifentanil (G I = 0.8 ± 0.26 mg and G II = 1.7 ± 0.42 mg; P = 0.001) and end-tidal sevoflurane concentration, with reduced doses of post-operative tramadol and diclofenac sodium. Time to the intended MAP was significantly less in G I than G II (59.1 ± 12.3 vs. 73.6 ± 16.4, respectively, with P = 0.001).

Conclusion:

Pre-operative oral gabapentin significantly reduced intra-operative remifentanil and sevoflurane requirements during hypotensive anaesthesia along with decreased post-operative analgesic requirement.

The Contribution of NMDA Receptors in Antinociceptive Effect of Pregabalin: Comparison of Two Models of Pain Assessment

Background

Pregabalin has shown remarkable antinociceptive effects in neuropathic pain; however, its efficacy against acute and visceral pain remained controversial.

Objectives

The present study aimed at investigating the involvement of N-methyl-D-aspartate (NMDA) receptors in the antinociceptive effect of pregabalin in both acute and visceral pain using and comparing hot plate test and writhing test in male mice.

Methods

NMDA (15 and 30 mg/kg), as an agonist or MK801 (0.02 and 0.05 mg/kg) as an NMDA receptor (NMDAR) antagonist, were injected intraperitoneally either alone or 15 minutes before a dose of pregabalin that produced almost 30% antinociception (100 mg/kg in hot plate test and 5 mg/kg in writhing tests). Then, the percentage of maximal possible effect (MPE%) at the 30th and 60th minutes in hot plate test and effect percentage (E%) in writhing test were measured and compared as antinociceptive indexes.

Results

In hot plate test, pretreatment with MK801 (0.05 mg/kg) significantly increased antinociceptive effect of 100 mg/kg pregabalin, but pretreatment with NMDA did not result in any effect. Pretreatment with MK801 in writhing test significantly increased the antinociceptive effect of 5 mg/kg pregabalin (In contrast to 30 mg/kg NMDA that significantly decreased it.). NMDA induced antinociception reduction or MK801 increased antinociception in writhing test were significantly higher than what was observed in hot plate test.

Conclusions

Our results suggested that pregabalin antinociception in acute and visceral pain is mediated through NMDA receptors. Although this effect depends on the dose of NMDAR ligand, it is more pronounced in the behavioral response in the writhing test.

Pregabalin Effect on Acute and Chronic Pain after Cardiac Surgery

Introduction. Pain after cardiac surgery affects long-term patient wellness. This study investigated the effect of preoperative pregabalin on acute and chronic pain after elective cardiac surgery with median sternotomy. Methods. Prospective double blind study. 93 cardiac surgery patients were randomly assigned into three groups: Group 1 received placebo, Group 2 received oral pregabalin 75 mg, and Group 3 received oral pregabalin 150 mg. Data were collected 8 hours, 24 hours, and 3 months postoperatively. Results. Patients receiving pregabalin required fewer morphine boluses (10 in controls versus 6 in Group 1 versus 4 in Group 2, p = 0.000) and had lower pain scores at 8 hours (4 versus 3 versus 3, p = 0.001) and 3 months (3 versus 2 versus 2, p = 0.000) and lower morphine consumption at 8 hours (14 versus 13 versus 12 mg, p = 0.000) and 24 hours (19.5 versus 16 versus 15 mg, p = 0.000). Percentage of patients with sleep disturbances or requiring analgesics was lower in the pregabalin group and even lower with higher pregabalin dose (16/31 versus 5/31 versus 3/31, p = 0.000, and 26/31 versus 16/31 versus 10/31, p = 0.000, resp.) 3 months after surgery. Conclusion. Preoperative oral pregabalin 75 or 150 mg reduces postoperative morphine requirements and acute and chronic pain after cardiac surgery.

Can Chronic Pain Be Prevented?

All chronic pain begins at some discrete point in time. Significant strides in the understanding of mechanisms and risk factors associated with the transition from a new, or acute, pain experience to a chronic pain condition have been made over the past 20 years. These insights provide the hope of one day being able to modify or even halt this pathophysiologic progression. This article reviews some of the current knowledge of this transition as well as the evidence currently available to best prevent and treat it using persistent surgical pain as a model.

[Perioperative gabapentin and pregabalin in cardiac surgery: a systematic review and meta-analysis]

OBJECTIVES

Sternotomy for cardiac surgeries causes significant postoperative pain and when not properly managed may cause significant morbidity. As neuropathic pain is a significant component here, gabapentin and pregabalin may be effective in these patients and may reduce postoperative opioid consumption. The purpose of this systematic review was to find out efficacy of gabapentin and pregabalin in acute postoperative pain after cardiac surgery.

METHODS

Published prospective human randomized clinical trials, which compared preoperative and/or postoperative gabapentin/pregabalin with placebo or no treatment for postoperative pain management after cardiac surgery has been included in this review.

RESULTS

Four RCTs each for gabapentin and pregabalin have been included in this systematic review. Three gabapentin and two pregabalin studies reported decrease in opioid consumption in cardiac surgical patients while one gabapentin and two pregabalin studies did not. Three RCTs each for gabapentin and pregabalin reported lower pain scores both during activity and rest. The drugs are not associated with any significant complications.

CONCLUSION

Despite lower pain scores in the postoperative period, there is insufficient evidence to recommend routine use of gabapentin and pregabalin to reduce opioid consumption in the cardiac surgical patients.

Use of preoperative gabapentin significantly reduces postoperative opioid consumption: a meta-analysis

OBJECTIVES

Effective postoperative pain management is crucial in the care of surgical patients. Opioids, which are commonly used in managing postoperative pain, have a potential for tolerance and addiction, along with sedating side effects. Gabapentin's use as a multimodal analgesic regimen to treat neuropathic pain has been documented as having favorable side effects. This meta-analysis examined the use of preoperative gabapentin and its impact on postoperative opioid consumption.

MATERIALS AND METHODS

A comprehensive literature search was conducted to identify randomized control trials that evaluated preoperative gabapentin on postoperative opioid consumption. The outcomes of interest were cumulative opioid consumption following the surgery and the incidence of vomiting, somnolence, and nausea.

RESULTS

A total of 1,793 patients involved in 17 randomized control trials formed the final analysis for this study. Postoperative opioid consumption was reduced when using gabapentin within the initial 24 hours following surgery (standard mean difference -1.35, 95% confidence interval [CI]: -1.96 to -0.73; P<0.001). There was a significant reduction in morphine, fentanyl, and tramadol consumption (P<0.05). While a significant increase in postoperative somnolence incidence was observed (relative risk 1.30, 95% CI: 1.10-1.54, P<0.05), there were no significant effects on postoperative vomiting and nausea.

CONCLUSION

The administration of preoperative gabapentin reduced the consumption of opioids during the initial 24 hours following surgery. The reduction in postoperative opioids with preoperative gabapentin increased postoperative somnolence, but no significant differences were observed in nausea and vomiting incidences. The results from this study demonstrate that gabapentin is more beneficial in mastectomy and spinal, abdominal, and thyroid surgeries. Gabapentin is an effective analgesic adjunct, and clinicians should consider its use in multimodal treatment plans among patients undergoing elective surgery.

Perioperative use of pregabalin for acute pain-a systematic review and meta-analysis

Evidence supporting postoperative pain management using pregabalin as an adjunct intervention across various surgical pain models is lacking. The objective of this systematic review was to evaluate "model-specific" comparative effectiveness and harms of pregabalin following a previously published systematic review protocol. MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched from inception through August 2013. Data were screened and single extraction with independent verification and dual risk of bias assessment was performed. Quality of evidence (QoE) was rated using the GRADE approach. Primary outcomes were pain relief at rest and on movement and reduction in postoperative analgesic consumption. A total of 1423 records were screened, and 43 studies were included. Perioperative pregabalin resulted in: 16% (95% confidence interval [CI], 9%-21%) reduction in analgesic consumption (moderate QoE, 24 trials) and a small reduction in the magnitude of pain in surgeries associated with pronociceptive pain. Per 1000 patients, 10 more will experience blurred vision (95% CI, 5-20 more; moderate QoE, 17 trials) and 41 more sedation (95% CI, 13-77 more, 17 trials). To prevent 1 case of perioperative nausea and vomiting, the number needed to treat is 11 (95% CI: 7-28, 25 trials). Inadequate evidence addressed outcomes of enhanced recovery and serious harms. Pregabalin analgesic effectiveness is largely restricted to surgical procedures associated with pronociceptive mechanisms. The clinical significance of observed pregabalin benefits must be weighed against the uncertainties about serious harms and enhanced recovery to inform the careful selection of surgical patients. Recommendations for future research are proposed.

Comparison of tapentadol with tramadol for analgesia after cardiac surgery

Background:

Tapentadol is a relatively new analgesic. We decided to compare it with tramadol for their various effects after cardiac surgery.

Setting:

A study in a tertiary care hospital.

Materials and Methods:

Sixty adults undergoing cardiac surgery were divided into 2 groups of 30 each by computerized random allotment (Group X = tapentadol 50 mg oral and Group Y = tramadol 100 mg oral). Informed Consent and Institutional Ethics Committee approval were obtained. The patients were given either drug X or drug Y after extubation in this single blinded study, wherein the data collectors and analyzers were blinded to the study. All patients received oral paracetamol qds and either drug X or drug Y tds. The pain score was noted on a Visual Analog Scale before each drug dose, 3 h later and on coughing. Heart rate, respiratory rate, and blood pressure were recorded before the drug dose and 3 h later. Postoperative nausea or vomiting (PONV), temperature, and modified Glasgow Coma Scale readings were recorded. The above readings were obtained for 6 doses (up to 48 h after extubation).

Statistics:

t-test, Pearson Chi-square test, Fisher exact test, and Mantel–Haenszel test were used for statistics.

Results:

Tapentadol group patients had significantly better analgesia 3 h after the drug and “on coughing” than tramadol group. The difference in their effects on blood creatinine levels, temperature, hemodynamics, oxygen saturation, and respiratory rate were not clinically significant. Tapentadol produced lesser drowsiness and lesser vomiting than tramadol.

Conclusions:

Tapentadol, due to its norepinephrine reuptake inhibition properties, in addition to mu agonist, is a better analgesic than tramadol and has lesser PONV.

Preventive analgesia and novel strategies for the prevention of chronic post-surgical pain

Chronic post-surgical pain (CPSP) is a serious complication of major surgery that can impair a patient's quality of life. The development of CPSP is a complex process which involves biologic, psychosocial, and environmental mechanisms that have yet to be fully understood. Currently perioperative pharmacologic interventions aim to suppress and prevent sensitization with the aim of reducing pain and analgesic requirement in acute as well as long-term pain . Despite the detrimental effects of CPSP on patients, the body of literature focused on treatment strategies to reduce CPSP remains limited and continues to be understudied. This article reviews the main pharmacologic candidates for the treatment of CPSP, discusses the future of preventive analgesia, and considers novel strategies to help treat acute post-operative pain and lessen the risk that it becomes chronic. In addition, this article highlights important areas of focus for clinical practice including: multimodal management of CPSP patients, psychological modifiers of the pain experience, and the development of a Transitional Pain Service specifically designed to manage patients at high risk of developing chronic post-surgical pain.

Efficacy of Pregabalin in Acute Postoperative Pain Under Different Surgical Categories: A Meta-Analysis

The efficacy of pregabalin in acute postsurgical pain has been demonstrated in numerous studies; however, the analgesic efficacy and adverse effects of using pregabalin in various surgical procedures remain uncertain. We aim to assess the postsurgical analgesic efficacy and adverse events after pregabalin administration under different surgical categories using a systematic review and meta-analysis of randomized controlled trials.A search of the literature was performed between August 2014 to April 2015, using PubMed, Ovid via EMBASE, Google Scholar, and ClinicalTrials.gov with no limitation on publication year or language. Studies considered for inclusion were randomized controlled trials, reporting on relevant outcomes (2-, 24-hour pain scores, or 24 hour morphine-equivalent consumption) with treatment with perioperative pregabalin.Seventy-four studies were included. Pregabalin reduced pain scores at 2 hours in all categories: cardiothoracic (Hedge's g and 95%CI, -0.442 [-0.752 to -0.132], P = 0.005), ENT (Hedge g and 95%CI, -0.684 [-1.051 to -0.316], P < 0.0001), gynecologic (Hedge g, 95%CI, -0.792 [-1.235 to -0.350], P < 0.0001), laparoscopic cholecystectomy (Hedge g, 95%CI, -0.600 [-0.989 to -0.210], P = 0.003), orthopedic (Hedge g, 95%CI, -0.507 [-0.812 to -0.202], P = 0.001), spine (Hedge g, 95%CI, -0.972 [-1.537 to -0.407], P = 0.001), and miscellaneous procedures (Hedge g, 95%CI, -1.976 [-2.654 to -1.297], P < 0.0001). Pregabalin reduced 24-hour morphine consumption in gynecologic (Hedge g, 95%CI, -1.085 [-1.582 to -0.441], P = 0.001), laparoscopic cholecystectomy (Hedge g, 95%CI, -0.886 [-1.652 to -0.120], P = 0.023), orthopedic (Hedge g, 95%CI, -0.720 [-1.118 to -0.323], P < 0.0001), spine (Hedge g, 95%CI, -1.016 [-1.732 to -0.300], P = 0.005), and miscellaneous procedures (Hedge g, 95%CI, -1.329 [-2.286 to -0.372], P = 0.006). Pregabalin resulted in significant sedation in all surgical categories except ENT, laparoscopic cholecystectomy, and gynecologic procedures. Postoperative nausea and vomiting was only significant after pregabalin in miscellaneous procedures.Analgesic effects and incidence of adverse effects of using pregabalin are not equal in different surgical categories.

The Role of NMDARs Ligands on Antinociceptive Effects of Pregabalin in the Tail Flick Test

Background:

Pregabalin as a new anticonvulsant has been used in different pain treatments.

Objectives:

The aim of this study was to investigate the role of N-methyl-D-aspartate (NMDA) ligands in antinociceptive effect of pregabalin in mice using tail flick.

Materials and Methods:

NMDA (15 and 30 mg/kg) as an agonist or MK801 (0.02 and 0.05 mg/kg) as an antagonist were injected intraperitoneally either alone or 15 minutes before antinociceptive dose of pregabalin (100 mg/kg). Then the latency times and %MPE were measured in the tail flick assay during 75 minutes.

Results:

NMDA and MK801 had no effects alone. NMDA pretreatment significantly decreased the latency times of pregabalin till 75^th minutes. In NMDA pretreated groups, %MPE₃₀ unlike %MPE₇₅ decreased significantly compared to those of pregabalin. MK801 delayed the latency times in pretreated groups, but %MPE₃₀ and %MPE₇₅ did not change significantly compared to pregabalin alone.

Conclusions:

Our findings support the role of NMDARs in pregabalin antinociception, because the NMDAR agonist, unlike the antagonist, decreased the antinociceptive effect of pregabalin, even if tail flick is not an adequate pain assessment method in this regard.

Drug utilisation study in patients receiving antiepileptic drugs in Colombia

INTRODUCTION

This study examines the indications according to which antiepileptic drugs are prescribed and used in a population of patients enrolled in the Colombian national health system (SGSSS).

METHODS

Retrospective cross-sectional study. From the pool of individuals in 34 Colombian cities who used antiepileptic drugs between 18 July, 2013 and 31 August, 2014 during a period of no less than 12 months, we obtained a random sample stratified by city. Socio-demographic, pharmacological and comorbidity variables were analysed. Continuous and categorical variables were compared, and logistic regression models were used.

RESULTS

Our patient total was 373 patients, with 197 women (52.1%) and a mean age of 41.9 ± 21.7 years; 65.4% of the patients were treated with monotherapy. The most frequently used drugs were valproic acid (53.1%) and carbamazepine (33.2%). Epilepsy was the most frequent indication (n=178; 47.7%); however, 52.3% of the patients were prescribed antiepileptics for different indications, especially neuropathic pain (26.8%), affective disorders (14.2%) and migraine prophylaxis (12.3%). A total of 81 patients with epilepsy (46.6%) displayed good seizure control while another 25 (14.4%) had drug-resistant epilepsy. In the multivariate analysis, medication adherence was associated with a lower risk of treatment failure in patients with epilepsy (OR: 0.27; 95%CI, 0.11-0.67).

CONCLUSIONS

In Colombia, antiepileptic drugs are being used for indications other than those originally intended. Monotherapy is the most commonly used treatment approach, together with the use of classic antiepileptic drugs.