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

Efficacy of gabapentin and pregabalin for treatment of post refractive surgery pain: a systematic review and meta-analysis

INTRODUCTION

For ophthalmic patients, eye discomfort is a major problem that requires efficient pain treatment techniques. Pregabalin and gabapentin have surfaced as viable treatments for post-refractive surgery pain. To manage pain after refractive surgery, gabapentin and pregabalin were evaluated in this systematic review and meta-analysis.

METHODOLOGY

A thorough search of databases including PubMed, Embase, Cochrane Library, and CINAHL was performed until March 2024. Inclusion criteria were randomized controlled trials assessing pregabalin and/or gabapentin's effectiveness in treating pain post-PRK, LASIK, and LASEK surgeries.

RESULTS

Six studies met inclusion criteria, comprising a total of 391 patients undergoing various corneal surgeries. The meta-analysis revealed that pregabalin was significantly more effective than placebo in reducing pain on the first and second postoperative days (SMD day 1: -0.32, 95% CI -0.54, -0.09; SMD day 2: -0.55, 95% CI -0.85, -0.25), while gabapentin showed significant pain reduction on the second day only (SMD day 2: -0.42, 95% CI -0.71, -0.13). Combined analysis for both medications showed significant pain reduction on the first- and second-days post-surgery. No significant increase in adverse events was associated with either medication. Publication bias was minimal except for a slight asymmetry noted on day 1 effectiveness.

CONCLUSION

Pregabalin and gabapentin are effective in reducing postoperative pain following refractive surgeries, with pregabalin showing a greater effect. Both medications are safe, with no significant increase in adverse events. Further research with standardized methodologies and long-term follow-up is recommended to optimize postoperative pain management in ocular surgeries.

Effects of pregabalin combined with tramadol/paracetamol on acute pain in patients with CT-guided puncture localization of pulmonary nodules

OBJECTIVE

To investigate the effects of pregabalin combined with tramadol/paracetamol on acute pain in patients with CT-guided puncture localization of pulmonary nodules.

MATERIALS AND METHODS

In this randomized, placebo-controlled and single-center study, 120 patients were allocated randomly to four groups: the control group (Group P), the pregabalin-placebo group (Group BP), the tramadol/paracetamol-placebo group (Group AP), and the pregabalin-tramadol/paracetamol group (Group AB). The primary outcome was the NRS (Numerical Rating Scale) score. Other outcomes included systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), pulse oxygen saturation (SpO2), the incidence of moderate to severe pain, the analgesia recovery ratio, the incidence of adverse drug reactions and patients' satisfaction.

RESULTS

No significant interaction was detected between the interventions (P = 0.752). The NRS score of the Taking pregabalin group and the Taking tramadol/paracetamol group were significantly lower than those of the Not-taking pregabalin group and the Not-taking tramadol/paracetamol group respectively (P < 0.05). There was significant difference in the NRS scores among the four groups (P < 0.001). The NRS score of Group AB was significantly lower than that of Group P (P < 0.001), Group BP (P < 0.001) and Group AP (P = 0.001). At the same time, the NRS scores of Group BP (P < 0.001) and Group AP (P < 0.001) were significantly lower than those of Group P, but there was no significant difference between Group BP and Group AP (P = 1.000). The SBP, DBP, HR, the incidence of moderate to severe pain and the analgesia recovery ratio of Group AB were significantly lower than those of Group P (P < 0.05), while the SpO2 and the number of people who were very satisfied were significantly higher than those of Group P (P < 0.05). There was no significant difference in the incidence of adverse drug reactions among the four groups (P = 0.272).

CONCLUSIONS

The combination or single use of pregabalin and tramadol/paracetamol can effectively relieve the acute pain after localization. Pregabalin combined with tramadol/paracetamol has the best analgesic effect and significantly reduces the hemodynamic fluctuations, with high safety and low incidence of adverse drug reactions, which has a certain clinical popularization and application value.

Analgesic Efficacy of Pre-operative Pregabalin in Dacryocystorhinostomy Surgery: A Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Trials

Dacryocystorhinostomy (DCR) is an effective surgical procedure for addressing lacrimal drainage problems. However, it can be a painful operation that involves incisions both inside and outside the eye, often leading to a high incidence of postoperative nausea and vomiting. Preemptive analgesics can be employed to alleviate this unrelieved pain. Nonetheless, many of the drugs used can induce a wide range of adverse effects. Therefore, the aim of this systematic review and meta-analysis is to assess the current evidence regarding the efficacy of pregabalin in managing postoperative pain following DCR surgery. We conducted a thorough search of five electronic databases, namely, PubMed, Web of Science, Scopus, Cochrane, and Google Scholar, to identify relevant randomized controlled trials (RCTs) published before September 2023. The quality of the included studies was assessed using the Cochrane Risk of Bias tool for RCTs. The outcomes we evaluated included postoperative pain, surgery duration, time to first analgesia, total pethidine consumption, and postoperative nausea and vomiting (PONV). Continues data reported as mean difference (MD), and dichotomous data reported as risk ratio (RR), with 95% confidence interval (CI). A pooled meta-analysis of three RCTs, including 240 patients in both the pregabalin and placebo groups, was conducted. The results revealed that the pooled MD in pain scores was significantly lower in patients treated with pregabalin compared to those receiving a placebo ((MD = -1.35 (95% CI: -1.83 to -0.87, p < 0.00001)). Additionally, the pooled MD of pethidine consumption was significantly lower in patients treated with pregabalin compared to those receiving a placebo (MD = -54.13 (95% CI: -103.77 to -4.50, p = 0.03)). However, there was no statistical significance between both groups in terms of time to first analgesia and duration of surgery (p > 0.05). On the other hand, the pooled RR of PONV was significantly lower in patients treated with pregabalin compared to those receiving a placebo (RR = 0.37 (95% CI: 0.24-0.57, p < 0.001)). This meta-analysis demonstrates that pregabalin is an effective and well-tolerated intervention for reducing postoperative pain and PONV following DCR surgery, without significantly affecting surgery duration or time to first analgesia. These findings support the use of pregabalin in improving patient comfort and outcomes in this surgical context.

Effect of Infraorbital and/or Infratrochlear Nerve Blocks on Postoperative Care in Patients with Septorhinoplasty: A Meta-Analysis

Background and Objectives: Through a comprehensive meta-analysis of the pertinent literature, this study evaluated the utility and efficacy of perioperative infraorbital and/or infratrochlear nerve blocks in reducing postoperative pain and related morbidities in patients undergoing septorhinoplasty. Materials and Methods: We reviewed studies retrieved from the PubMed, SCOPUS, Embase, Web of Science, and Cochrane databases up to August 2023. The analysis included a selection of seven articles that compared a treatment group receiving perioperative infraorbital and/or infratrochlear nerve blocks with a control group that either received a placebo or no treatment. The evaluated outcomes covered parameters such as postoperative pain, the amount and frequency of analgesic medication administration, the incidence of postoperative nausea and vomiting, as well as the manifestation of emergence agitation. Results: The treatment group displayed a significant reduction in postoperative pain (mean difference = -1.7236 [-2.6825; -0.7646], I2 = 98.8%), as well as a significant decrease in both the amount (standardized mean difference = -2.4629 [-3.8042; -1.1216], I2 = 93.0%) and frequency (odds ratio = 0.3584 [0.1383; 0.9287], I2 = 59.7%) of analgesic medication use compared to the control. The incidence of emergence agitation (odds ratio = 0.2040 [0.0907; 0.4590], I2 = 0.0%) was notably lower in the treatment group. The incidence of postoperative nausea and vomiting (odds ratio = 0.5393 [0.1309; 2.2218], I2 = 60.4%) showed a trend towards reduction, although it was not statistically significant. While no adverse effects reaching statistical significance were reported in the analyzed studies, hematoma (proportional rate = 0.2133 [0.0905; 0.4250], I2 = 76.9%) and edema (proportional rate = 0.1935 [0.1048; 0.3296], I2 = 57.2%) after blocks appeared at rates of approximately 20%. Conclusions: Infraorbital and/or infratrochlear nerve blocks for septorhinoplasty effectively reduce postoperative pain and emergence agitation without notable adverse outcomes.

Perioperative Anxiolysis and Analgesic Effect after Premedication with Melatonin and Pregabalin in Total Hip Arthroplasty under Spinal Anaesthesia: A Prospective Comparative Trial

Background

Preoperative anxiety plays a critical role in post-operative pain response and other outcomes. Melatonin is a naturally secreted hormone which has anxiolytic, sedative, and analgesic properties. Pregabalin, analogue of gabapentin which has property of anxiolytic and analgesic effects.

Materials and Methods

Total 96 patients undergoing total hip arthroplasty, divided into 3 groups of 32 each and were given placebo (group I), melatonin 6 mg (group II), and pregabalin 150 mg (group III). Anxiety level, postoperative pain score, sedation level and duration as well as characteristics of spinal anaesthesia were assessed with other vital parameters.

Results

Group I showed an increment in the anxiety score from baseline whereas in group II and group III, there was a decline in pre-operative anxiety score from baseline at all the periods of observation and more significantly in group III. Visual analogue scale (VAS) score and total dose of rescue analgesia were highest in group I, but group II and group III were comparable to each other. However, the durations of spinal anaesthesia and motor blockade showed a statistically significant difference with maximum duration in group III followed by II and then I. The level of sedation among the three groups were comparable at all the periods of observation.

Conclusions

Pregabalin was found better for perioperative anxiolysis, post-operative analgesia and for prolongation of duration of spinal anaesthesia when compared to melatonin.

Pregabalin supplementation for the pain relief of septorhinoplasty: a meta-analysis study

BACKGROUND

Pregabalin supplementation may have some potential in improving pain relief in patients with septorhinoplasty, and this meta-analysis aims to explore the impact of pregabalin supplementation on pain control for septorhinoplasty.

METHODS

PubMed, EMbase, Web of science, EBSCO and Cochrane library databases were systematically searched, and we included randomized controlled trials (RCTs) assessing the effect of pregabalin supplementation on pain control for septorhinoplasty.

RESULTS

Six RCTs were finally included in the meta-analysis. Overall, when compared with control intervention for septorhinoplasty, pregabalin intervention showed significantly reduced pain scores at 1 h (SMD - 1.05; 95% CI - 1.85 to - 0.24; P = 0.01), 2 h (SMD - 1.01; 95% CI - 1.83 to - 0.20; P = 0.02), 6 h (SMD - 1.00; 95% CI - 1.47 to - 0.54; P < 0.0001) and 12 h (SMD - 0.69; 95% CI - 1.35 to - 0.02; P = 0.04), as well as rescue analgesics (OR 0.17; 95% CI 0.07 to 0.44; P = 0.0002), but had no notable influence on nausea and vomiting (OR 0.67; 95% CI 0.30 to 1.46; P = 0.31), or drowsiness (OR 1.22; 95% CI 0.64 to 2.35; P = 0.54).

CONCLUSIONS

Pregabalin supplementation benefits to pain control after septorhinoplasty.

Development and Validation of a Model for Opioid Prescribing Following Gynecological Surgery

IMPORTANCE

Overprescription of opioid medications following surgery is well documented. Current prescribing models have been proposed in narrow patient populations, which limits their generalizability.

OBJECTIVE

To develop and validate a model for predicting outpatient opioid use following a range of gynecological surgical procedures.

DESIGN, SETTING, AND PARTICIPANTS

In this prognostic study, statistical models were explored using data from a training cohort of participants undergoing gynecological surgery for benign and malignant indications enrolled prospectively at a single institution's academic gynecologic oncology practice from February 2018 to March 2019 (cohort 1) and considering 39 candidate predictors of opioid use. Final models were internally validated using a separate testing cohort enrolled from May 2019 to February 2020 (cohort 2). The best final model was updated by combining cohorts, and an online calculator was created. Data analysis was performed from March to May 2020.

EXPOSURES

Participants completed a preoperative survey and weekly postoperative assessments (up to 6 weeks) following gynecological surgery. Pain management was at the discretion of clinical practitioners.

MAIN OUTCOMES AND MEASURES

The response variable used in model development was number of pills used postoperatively, and the primary outcome was model performance using ordinal concordance and Brier score.

RESULTS

Data from 382 female adult participants (mean age, 56 years; range, 18-87 years) undergoing gynecological surgery (minimally invasive procedures, 158 patients [73%] in cohort 1 and 118 patients [71%] in cohort 2; open surgical procedures, 58 patients [27%] in cohort 1 and 48 patients [29%] in cohort 2) were included in model development. One hundred forty-seven patients (38%) used 0 pills after hospital discharge, and the mean (SD) number of pills used was 7 (10) (median [IQR], 3 [0-10] pills). The model used 7 predictors: age, educational attainment, smoking history, anticipated pain medication use, anxiety regarding surgery, operative time, and preoperative pregabalin administration. The ordinal concordance was 0.65 (95% CI, 0.62-0.68) for predicting 5 or more pills (Brier score, 0.22), 0.65 (95% CI, 0.62-0.68) for predicting 10 or more pills (Brier score, 0.18), and 0.65 (95% CI, 0.62-0.68) for predicting 15 or more pills (Brier score, 0.14).

CONCLUSIONS AND RELEVANCE

This model provides individualized estimates of outpatient opioid use following a range of gynecological surgical procedures for benign and malignant indications with all model inputs available at the time of procedure closing. Implementation of this model into the clinical setting is currently ongoing, with plans for additional validation in other surgical populations.

Postoperative Pain Management in Enhanced Recovery Pathways

Postoperative pain is a common but often inadequately treated condition. Enhanced recovery pathways (ERPs) are increasingly being utilized to standardize perioperative care and improve outcomes. ERPs employ multimodal postoperative pain management strategies that minimize opioid use and promote recovery. While traditional opioid medications continue to play an important role in the treatment of postoperative pain, ERPs also rely on a wide range of non-opioid pharmacologic therapies as well as regional anesthesia techniques to manage pain in the postoperative setting. The evidence for the use of these interventions continues to evolve rapidly given the increasing focus on enhanced postoperative recovery. This article reviews the current evidence and knowledge gaps pertaining to commonly utilized modalities for postoperative pain management in ERPs.

A single dose of pre-operative pregabalin reduces post-operative opioid use after orthotopic liver transplantation

Multimodal pain management strategies including pregabalin (PGB) have been shown to reduce pain and opioid use after many types of surgeries. This was a single-center, retrospective study aimed to determine whether a single pre-operative dose of PGB reduces opioid requirements and post-operative pain after orthotopic liver transplantation (OLT). Outcomes included the mean morphine milligram equivalents used; the proportion of patients with no pain documented; and the maximum level of pain documented within the first 24h and in the 24-72h following OLT. A total of 44 patients received PGB vs 57 who received standard of care. Baseline demographics were comparable between groups. Patients who received PGB required 70% and 54% less opioids within the first 24h and subsequent 24-72h post-OLT, respectively (p-values < .001). In the first 24h post-OLT, there were more patients with no documented pain, and fewer with severe pain in the PGB group, but these were not significant. A greater proportion in the PGB group reported a maximum of mild pain (p = .039). This study demonstrated that a single dose of pre-operative PGB significantly reduced opioid use in the first 72 h after OLT. Larger studies will help determine the safety and efficacy of PGB in this setting.

Effect of pregabalin on nociceptive thresholds and immune responses in a mouse model of incisional pain

Background

It is known that some analgesics as well as pain can affect the immune system. The aim of this study was to investigate the analgesic effect and immunomodulation of pregabalin (PGB) in a mouse incisional pain model.

Methods

A postoperative pain model was induced by hind paw plantar incision in male BALB/c mice. Mice were randomly divided into four groups (n = 8) a saline-treated incision (incision), PGB-treated incision (PGB-incision), sham controls without incision or drug treatment (control), and a PGB-treated control (PGB-control). In the PGB treated groups, PGB was administered intraperitoneally (IP) 30 minutes before and 1 hour after the plantar incision. Changes of the mechanical nociceptive thresholds following incision were investigated. Mice were euthanized for spleen harvesting 12 hours after the plantar incision, and natural killer (NK) cytotoxicity to YAC 1 cells and lymphocyte proliferation responses to phytohemagglutinin were compared among these four groups.

Results

Mechanical nociceptive thresholds were decreased after plantar incision and IP PGB administration recovered these decreased mechanical nociceptive thresholds (P < 0.001). NK activity was increased by foot incision, but NK activity in the PGB-incision group was significantly lower than that in the Incision group (P < 0.001). Incisional pain increased splenic lymphocyte proliferation, but PGB did not alter this response.

Conclusions

Incisional pain alters cell immunity of the spleen in BALB/c mice. PGB showed antinocieptive effect on mouse incisional pain and attenuates the activation of NK cells in this painful condition. These results suggest that PGB treatment prevents increases in pain induced NK cell activity.

Utilizing multimodal analgesia to evaluate postoperative analgesic requirements in kidney transplant recipients

The use of non-opioid analgesics following surgery has proven beneficial in managing pain and decreasing adverse outcomes following surgery. Data assessing outcomes related to opioid use is limited in kidney transplant recipients (KTRs). We evaluated the effectiveness of implementing a reduced to no opioid use protocol in KTRs. This retrospective cohort study included adult KTRs between January 2017 and July 2019 with a multimodal analgesic protocol (MAP), focused on limiting opioids, implemented in August 2018. We compared analgesic requirements in morphine milligram equivalents (MME) during transplant admissions between the MAP cohort and traditional cohort. There were 217 KTRs who met the criteria. Inpatient opioid use was significantly reduced in the MAP cohort (16.5 ± 19.2 MME/day vs 24.7 ± 19.7 MME/day; P <.05) with no significant difference in pain scores. No use of opioids within six months of discharge was significantly increased in the MAP cohort (50% vs 7%; P <.001), and there were no reported deaths at six months in either cohort. The use of multimodal analgesia is beneficial in KTRs to provide adequate pain control with limited to no exposure of opioids during admission or at discharge.

Effects of pre-emptive pregabalin and multimodal anesthesia on postoperative opioid requirements in patients undergoing robot-assisted laparoscopic prostatectomy

BACKGROUND

Previous findings indicate that pre-emptive pregabalin as part of multimodal anesthesia reduces opioid requirements compared to conventional anesthesia in patients undergoing robot-assisted laparoscopic prostatectomy (RALP). However, recent studies show contradictory evidence suggesting that pregabalin does not reduce postoperative pain or opioid consumption after surgeries. We conducted a register-based analysis on RALP patients treated over a 5-year period to evaluate postoperative opioid consumption between two multimodal anesthesia protocols.

METHODS

We retrospectively evaluated patients undergoing RALP between years 2015 and 2019. Patients with American Society of Anesthesiologists status 1-3, age between 30 and 80 years and treated with standard multimodal anesthesia were included in the study. Pregabalin (PG) group received 150 mg of oral pregabalin as premedication before anesthesia induction, while the control (CTRL) group was treated conventionally. Postoperative opioid requirements were calculated as intravenous morphine equivalent doses for both groups. The impact of pregabalin on postoperative nausea and vomiting (PONV), and length of stay (LOS) was evaluated.

RESULTS

We included 245 patients in the PG group and 103 in the CTRL group. Median (IQR) opioid consumption over 24 postoperative hours was 15 (8-24) and 17 (8-25) mg in PG and CTRL groups (p = 0.44). We found no difference in postoperative opioid requirement between the two groups in post anesthesia care unit, or within 12 h postoperatively (p = 0.16; p = 0.09). The length of post anesthesia care unit stay was same in each group and there was no difference in PONV Similarly, median postoperative LOS was 31 h in both groups.

CONCLUSION

Patients undergoing RALP and receiving multimodal analgesia do not need significant amount of opioids postoperatively and can be discharged soon after the procedure. Pre-emptive administration of oral pregabalin does not reduce postoperative opioid consumption, PONV or LOS in these patients.

Role of Pregabalin to Decrease Postoperative Pain in Microdiscectomy: A Randomized Clinical Trial

Purpose The purpose of this study is to compare the effect of pregabalin in reducing the neuropathic pain in postoperative patients who have undergone single-level microdiscectomy for prolapsed intervertebral lumbar disc. Methods A randomized control clinical trial was conducted from June 2018 to April 2020 in three campuses Dr. Ziauddin University Hospital, Karachi, by two spinal surgeons. This study included 84 patients who underwent either emergency or elective microdiscectomy surgery. The patients randomized into two equal groups of 42, (group-A: pregabalin) and (group-B: placebo). Both groups also received routine analgesia along with the pregabalin and placebo capsules. In the intervention group, pregabalin was administered preoperative and postoperative defined times. The pain scores were recorded by visual analog scale (VAS) and Roland-Morris score system on the preoperative day and compared to the scores on follow-up on postoperative day seven. Results The pain scores were significantly better in group-A compared to group-B with similar baseline variables. The mean VAS scores of pains in group-A on postoperative day seven on follow-up were compared to VAS pain scores in group-B showing better pain control. The Roland-Morris scores were also significantly better for group-A. Conclusions The use of pregabalin in addition to the routine analgesia has better control of postoperative neuropathic pain in patients with single-level microdiscectomy compared to the patients who are receiving only routine analgesia. Other factors like cost, dose, side effects, and frequency should also be considered.

Effects of Adding a Combined Infraorbital and Infratrochlear Nerve Block to General Anaesthesia in Septorhinoplasty

Purpose

In this study, we evaluated the hypothesis that preoperative bilateral infraoptic nerve (ION) and infratrochlear nerve (ITN) blocks under general anesthesia with sevoflurane and remifentanil reduced the incidence of emergence agitation (EA), pain scores, and the analgesic consumption after the septorhinoplasty.

Patients and Methods

Our study was conducted as a prospective randomized, double-sided blind study. Fifty-two patients whose septorhinoplasty operation was planned under general anesthesia were included in the study. Patients were randomly distributed to either the ION and ITN blocks were performed. Group 1: Bilateral ION and ITN blocks were performed; Group 2: ION and ITN blocks were not performed. Duration of the surgery and anesthesia, Riker Sedation-Agitation Scale (RSAS) score, EA presence, duration of postoperative analgesia, numerical rating scale (NRS) scores, and cumulative dexketoprofen consumption were recorded.

Results

The RSAS score, NRS score and cumulative dexketoprofen consumption of the patients in Group 1 were statistically significantly lower than the patients in Group 2 (p<0.05). It was also found that patients in Group 1 (n: 8/26) had less EA compared to patients in Group 2 (n: 16/26) and this difference was statistically significant (p: 0.026). Postoperative analgesia duration of patients in Group 1 was found to be statistically significantly higher than patients in Group 2 (p: <0.001). In addition, the number of patients given postoperative dexketoprofen in Group 1 (n: 8/26) was found to be statistically significantly lower than patients in Group 2 (n: 25/26). (p: <0.001).

Conclusion

Bilateral ION and ITN blocks in septorhinoplasty operation is an effective, reliable and simple technique in the treatment of postoperative pain.

The Opioid Wars-CON: The Risks of Opioids for Pain Management Outweigh the Benefits

The entire field of medicine, not just anesthesiology, has grown comfortable with the risks posed by opioids; but these risks are unacceptably high. It is time for a dramatic paradigm shift. If used at all for acute or chronic pain management, they should be used only after consideration and maximizing the use of nonopioid pharmacologic agents, regional analgesia techniques, and nonpharmacologic methods. Opioids poorly control pain, their intraoperative use may increase the risk of recurrence of some types of cancer, and they have a large number of both minor and serious side effects. Furthermore, there are a myriad of alternative analgesic strategies that provide superior analgesia, decrease recovery time, and have fewer side effects and risks associated with their use. In this article the negative consequences of opioid use for pain, appropriate alternatives to opioids for analgesia, and the available evidence in pediatric populations for both are described.

Perioperative Pregabalin for Preventive Analgesia in Breast Cancer Surgery: A Meta-analysis of Randomized Controlled Trials

OBJECTIVES

Pregabalin is a drug for neuropathic pain. Antipronociceptive properties of pregabalin have led to its recent use as an adjuvant to the multimodal postoperative pain regimen. This meta-analysis was conducted to evaluate the efficacy of perioperative pregabalin on acute and chronic postsurgical pain (CPSP) after breast cancer surgery.

METHODS

A meta-analysis including 8 randomized controlled trials searched from MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials was conducted. Subgroup analysis was performed according to doses and timecourse of pregabalin administration. Review Manager 5.3 was selected to conduct the meta-analysis.

RESULTS

Preoperative pregabalin in breast cancer surgery alleviated acute postoperative pain at rest 24 hours after surgery by 0.31 points on an 0 to 10 Numerical Rating Scale (95% confidence interval [CI] -0.57 to -0.05). Morphine consumption showed a decrease in postoperative use by 1.09 mg (95% CI: -1.61 to -0.57). The incidence of CPSP 3 months after surgery was reduced to 46% (95% CI: 0.25-0.85). Postoperative nausea and vomiting, dizziness, and sedation showed no overall significant reductions. However, a decrease in the incidence of postoperative nausea and vomiting and an increase in the incidence of dizziness were noted when patients received 300 mg of pregabalin before surgery.

DISCUSSION

This study demonstrated that pregabalin showed more efficacy on chronic pain than acute pain after a breast cancer surgery. Further study based on doses and treatment course of pregabalin should be conducted to establish stronger evidence of treatment effects.

Perioperative Use of Gabapentinoids for the Management of Postoperative Acute Pain

Background

Widely used for acute pain management, the clinical benefit from perioperative use of gabapentinoids is uncertain. The aim of this systematic review was to assess the analgesic effect and adverse events with the perioperative use of gabapentinoids in adult patients.

Methods

Randomized controlled trials studying the use of gabapentinoids in adult patients undergoing surgery were included. The primary outcome was the intensity of postoperative acute pain. Secondary outcomes included the intensity of postoperative subacute pain, incidence of postoperative chronic pain, cumulative opioid use, persistent opioid use, lengths of stay, and adverse events. The clinical significance of the summary estimates was assessed based on established thresholds for minimally important differences.

Results

In total, 281 trials (N = 24,682 participants) were included in this meta-analysis. Compared with controls, gabapentinoids were associated with a lower postoperative pain intensity (100-point scale) at 6 h (mean difference, −10; 95% CI, −12 to −9), 12 h (mean difference, −9; 95% CI, −10 to −7), 24 h (mean difference, −7; 95% CI, −8 to −6), and 48 h (mean difference, −3; 95% CI, −5 to −1). This effect was not clinically significant ranging below the minimally important difference (10 points out of 100) for each time point. These results were consistent regardless of the type of drug (gabapentin or pregabalin). No effect was observed on pain intensity at 72 h, subacute and chronic pain. The use of gabapentinoids was associated with a lower risk of postoperative nausea and vomiting but with more dizziness and visual disturbance.

Conclusions

No clinically significant analgesic effect for the perioperative use of gabapentinoids was observed. There was also no effect on the prevention of postoperative chronic pain and a greater risk of adverse events. These results do not support the routine use of pregabalin or gabapentin for the management of postoperative pain in adult patients.

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Evaluation of the Efficacy of Prolonged Pregabalin Administration Before and After Surgery in Patients Undergoing Arthroscopic Anterior Cruciate Ligament Repair: A Prospective, Randomized, Double-blind Study

CONTEXT AND OBJECTIVE

Reconstruction of the knee ligament causes postoperative pain and delayed rehabilitation.

OBJECTIVE

The primary objective of this study was to evaluate the effect of a prolonged preoperative and postoperative pregabalin use for arthroscopic anterior cruciate ligament repair.

MATERIALS AND METHODS

Group 1 (N=25) patients received pregabalin 75 mg/d, and group 2 (N=25) received placebo, 7 days before and 7 days after surgery. Spinal anesthesia was performed using 0.5% hyperbaric bupivacaine (15 mg). The following were evaluated: pain intensity immediately after the surgery, and 12 hours, 24 hours, 1 week, 2 weeks, 1 month, and 2 months after the surgery using a Numerical Rating Scale; dose of postoperative supplementary analgesic for 2 months; time to first analgesic requirement; and side effects during 2 months. For supplementation, the participants received 1 g dipyrone; if there was no pain control, 100 mg ketoprofen was administered; if there was no effect, 100 mg tramadol was administered; and if there was no pain control, 5 mg intravenous morphine was administered until pain control.

RESULTS

There was no difference between the groups with regard to pain intensity (P=0.077). In the pregabalin group, morphine consumption was lower at 12 hours (P=0.039) and 24 hours (P=0.044) after surgery, and the consumption of tramadol and ketoprofen was lower 24 hours after surgery. There was no significant difference in the incidence of nausea and vomiting. Dizziness was higher in the pregabalin group (group 1=12 patients; group 2=3 patients; P=0.005).

DISCUSSION

A prolonged preoperative and postoperative pregabalin prescription for anterior cruciate ligament repair decreased the need for supplementary analgesics during the first 24 postoperative hours but increased dizziness.

Pain management in the orthopaedic trauma patient: Non-opioid solutions

When treating pain in the orthopaedic trauma patient opioids have classically represented the mainstay of treatment. They are relatively inexpensive and modestly effective for basic pain management. However, they are fraught with considerable side effects as well as the very high risk of addiction. Their use in pain management has been implicated in the opioid epidemic. For this reason, as well as their only moderate efficacy, alternative modes of treatment have been sought for both the patient with isolated limb trauma and the patient with poly trauma. We review alternative treatment methods in pain management for those with isolated limb trauma and poly trauma. These methods include topical agents, as well as non steroidal anti-inflammatory medications, acetaminophen, gabapetoids, intravenous agents, varying degrees of local anesthetic infiltration and peripheral nerve blocks, and the newer modality of fascial plane blocks. Often, it is a combination of these analgesic modalities that gives the most optimum treatment for the trauma patient. This also, more frequently than not, must be individually tailored to the patient, as no two patients act the same in this regard. It is therefore of importance that the physician managing such patients's pain be experienced and well-versed in all these treatment modalities. We also provide a basic stepwise algorithm we have found useful in treating those with single extremity or single site trauma versus those patients with poly trauma and resultant multiple sources as pain generators. It is hoped that this breakdown of the different modalities along with a better understanding of each modality's potential benefits and indications will aid the surgeon in providing better care to patients following orthopedic trauma.

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.

Effect of Pregabalin on Postcraniotomy Pain in Patients Undergoing Supratentorial Tumor Surgery: A Randomized, Double-Blind, Placebo-Controlled Trial

Background and Objectives Suboptimal management of postcraniotomy pain causes sympathetic and hemodynamic perturbations, leading to deleterious effects on the neurological system and overall patient outcome. Opioids are the mainstay of postoperative pain management but have various problems when given in high doses, or for prolonged durations in neurosurgical patients. The ideal method of pain control following craniotomy generally relies on a combination of various drugs. Oral pregabalin may be an attractive alternative in these patients.

Materials and Methods Sixty, American Society of Anesthesiologists class I and II patients posted for elective supratentorial craniotomy, aged 18 and 60 years, were randomly assigned into three groups of 20 each to receive oral placebo (Group A), pregabalin 75 mg (Group B), or pregabalin 150 mg (Group C) before the induction of anesthesia. At the end of the surgery, patient-controlled analgesia was started with intravenous fentanyl. Visual analog scale (VAS) score was recorded every 2 hours for 24 hours, along with total postoperative fentanyl requirement.

Results There were no differences in sex, duration of surgery or anesthesia and total intraoperative fentanyl administered among the three groups. The median postoperative VAS score (Group A—18.0, Group B—20, and Group C—22.0; p = 0.63) was similar in all the groups. However, postoperative fentanyl requirement over 24 hours was least in the group that received 150 mg pregabalin (Group A—190 μg, Group B—240 μg, and Group C—100 μg; p = 0.03).

Conclusions Even though pain scores were not significantly different, patients receiving 150 mg oral pregabalin required the least amount of postoperative opioids.

Effect of Intravenous Dexmedetomidine During General Anesthesia on Acute Postoperative Pain in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Dexmedetomidine has been shown to have an analgesic effect. However, no consensus was reached in previous studies.

METHODS

Electronic databases such as PubMed, Embase, and Cochrane Central were searched for relevant randomized controlled trials. The relative risk and weighted mean difference (WMD) were used to analyze the outcomes. Random-effects model was used for meta-analysis.

RESULTS

Compared with the normal saline group, patients using DEX showed a significantly decreased pain intensity within 6 hours [WMD=-0.93; 95% confidence interval (CI), -1.34 to -0.53) and at 24 hours after surgery (WMD=-0.47; 95% CI, -0.83 to -0.11). DEX usage significantly reduced the cumulative opioids consumption at 24 hours after surgery (WMD=-6.76; 95% CI, -10.16 to -3.35), decreased the rescue opioids consumption in postanesthesia care unit (WMD=-3.11; 95% CI, -5.20 to -1.03), reduced the risk of rescue analgesics (relative risk=0.49; 95% CI, 0.33-0.71), and the interval to first rescue analgesia was prolonged (WMD=34.93; 95% CI, 20.27-49.59).

CONCLUSIONS

Intravenous DEX effectively relieved the pain intensity, extended the pain-free period, and decreased the consumption of opioids during postoperative recovery of adults in general anesthesia.

The Effect of Perioperative Pregabalin on Pain after Arthroscopic Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

Pain after anterior cruciate ligament (ACL) reconstruction is usually intense in the early postoperative period, but the efficacy of a multimodal analgesia approach remains controversial. This study aimed to investigate the analgesic efficacy of pregabalin in multimodal analgesia after ACL reconstruction. Patients who underwent ACL reconstruction under spinal anesthesia and agreed to use intravenous patient-controlled analgesia (IV-PCA) were randomly administered placebo (control group, n = 47) or pregabalin 150 mg (pregabalin group, n = 46) 1 h before surgery and 12 h after initial treatment. Pain by verbal numerical rating scale (VNRS) at rest and with passive flexion of knee was assessed at postoperative 12, 24, and 36 h and 2 weeks. IV-PCA consumption, rescue analgesic use, and side effects were also evaluated. Lower scores of VNRS were obtained with passive flexion of knee in the pregabalin group than in the control group at postoperative 24 (7(4-8) vs. 8(6-9), p = 0.043) and 36 h (4(3-7) vs. 5(4-9), p = 0.042), and lower value of VNRS at rest was observed in the pregabalin group [0(0-1)] than in the control group [1(0-2)] at postoperative 2 weeks (p < 0.001). No differences were obtained for IV-PCA consumption, rescue analgesic use, and side effects except for dizziness for postoperative 12 h. Pregabalin as an adjuvant to multimodal analgesic regimen significantly reduced early postoperative pain in patients undergoing ACL reconstruction.

Low-dose preoperative pregabalin improves postoperative pain management in septorhinoplasty surgery: a double-blind randomized clinical trial

PURPOSE

To evaluate the efficacy of single low dose (75 mg) preoperative pregabalin in reducing post-operative pain of septorhinoplasty.

METHODS

A double blind single center Randomized controlled trial based on block randomization. In the pregabalin group (PG) 34 participants received 75 mg pregabalin orally one hour before anesthesia induction while in control group (CG) 34 participants received a placebo. Pain and sedation were repeatedly measured with Visual Analouge Scale (VAS) and Riker Sedation-Agitation Scale (RSAS) respectively, 0.5, 1, 2, 6, 24 hours postextubation. Cumulative doses of fentanyl and ibuprofen received in both groups were compared.

RESULTS

Thirty-two of the participants in PG and 33 of the participants in CG completed the study. The Mean VAS pain score was less in PG versus CG 30 min postoperatively (2.30 ± 1.30 vs. 4.85 ± 1.17), one hour (2.28 ± 0.92 vs. 4.27 ± 0.78), two hours (2.11 ± 0.88 vs. 3.60 ± 0.61) and six hours (1.47 0.62 vs. 2.76 ± 0.91) but not 24-hours postoperatively (0.84 ± 0.62 vs. 1.09 ± 0.92). Participants in the PG were less agitated during early post-extubation period (at 10 min: RSAS 3.93 ± 0.43 vs. 4.42 ± 0.50) and more alert during the first hour post-extubation (at 60 min: RSAS 3.90 ± 0.29 vs. 3.36 ± 0.69). The total dose of rescue fentanyl and ibuprofen was lower in the PG compared to the CG.

CONCLUSIONS

A single dose of 75 mg pregabalin is very effective for pain control after septorhinoplasty procedure when administered one hour before anesthesia induction. Side effects are rare and opioid sparing was noted.

TRIAL REGISTRATION

Clinical trial number: IRCT2017043033706N1.

Effect of preoperative pregabalin on analgesia and interleukins after lumbotomy: prospective, randomized, comparative, double-blind study

Background

Pregabalin is an anticonvulsant and has been used for postoperative analgesia. This study aimed to assess the effect of a single preoperative dose of pregabalin for analgesia after nephrectomy.

Methods

The study was prospective, randomized, comparative, and double-blinded, conducted in 40 kidney transplant donors, between 18 and 60 years, American Society of Anesthesia physical status I or II. Epidural anesthesia was performed with 15 mL of 0.5% ropivacaine single shot and general anesthesia with 3 µg/kg of fentanyl, propofol, atracurium, and sevoflurane, and 50% of oxygen without nitrous oxide. Patients in group 1 were administered 300 mg of pregabalin and those in group 2 were administered placebo, in identical capsules, 1 hour prior to surgery. Postoperative analgesia was supplemented with tramadol. The following parameters were assessed: pain intensity after 6 and 24 hours; pain threshold, from the thenar and peri-incisional region, analgesic supplementation; ILs (IL6, IL8, and IL10) prior to surgery and after 6 and 24 hours.

Results

The pain intensity was lower with pregabalin after 24 hours (G1: 2.5±2.4, G2: 3.0±2.6). There was no difference in the sensitivity of the thenar and peri-incisional region after 6 and 24 hours; in the number of patients requiring supplementation (G1=15%, G2=45%); concentrations of IL-6, IL-8, and IL-10; and side effects (nausea, vomiting, dizziness, and pruritus).

Conclusion

Pregabalin in a single preoperative dose of 300 mg reduced pain intensity 24 hours after lumbotomy.

Perioperative use of gabapentinoids for the management of postoperative acute pain: protocol of a systematic review and meta-analysis

BACKGROUND

Opioids are commonly used for the management of postoperative pain, but their use is limited by important adverse events, such as respiratory depression and the potential for addiction. Multimodal opioid-sparing analgesia regimens can be effectively employed to manage postoperative pain and reduce exposure to opioids. Gabapentinoids (pregabalin and gabapentin) represent an attractive class of drugs for use in multimodal regimens. The American Pain Society recommends the use of gabapentinoids during the perioperative period; however, evidence to inform such a recommendation is unclear.

METHODS

We will conduct a systematic review and meta-analysis of randomized clinical trials evaluating the use of systemic gabapentinoids, in comparison to other analgesic regimens or placebo in adult patients undergoing surgery. We will search MEDLINE, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), the Web of Science, and ClinicalTrials.gov databases for relevant citations. Our primary outcome will be intensity of postoperative acute pain (12 h). Our secondary outcomes will be postoperative pain intensity at 6, 24, 48 h, and 72 h, cumulative dose of opioids administered within 24, 48, and 72 h following surgery, the length of stay, chronic pain, and adverse events. Two investigators will independently select trials and extract data. We will evaluate the risk of bias of included trials using the Cochrane risk of bias tools. We will represent pooled continuous data as weighted mean differences and pooled dichotomous data as risk ratios with a 95% confidence interval. We will use random effect models and assess statistical heterogeneity with the I2 index.

DISCUSSION

Our study will provide the best level of evidence to inform the effect of gabapentinoids in the management of postoperative acute pain.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42017067029.

The efficacy of pregabalin for the management of acute and chronic postoperative pain in thoracotomy: a meta-analysis with trial sequential analysis of randomized-controlled trials

PURPOSE

Pregabalin is commonly used as an analgesic for neuropathic pain. But pregabalin as an adjunct to a multimodal analgesic regimen - although standard clinical protocol in some settings - has remained controversial. This meta-analysis was conducted to identify the efficacy of pregabalin for management of postoperative pain in thoracotomy.

MATERIALS AND METHODS

Pubmed, Embase, Cochrane, Web of Science, Springer, and Clinical Trial Register database were searched for randomized controlled trials (RCTs) of pregabalin in preventing postoperative pain in thoracotomy. Review Manager 5.3 and STATA 12.0 were selected to conduct the meta-analysis. Trial sequential analysis was used to control random errors and calculate the required information size.

RESULTS

Nine RCTs with 684 patients were included in our meta-analysis. Outcomes favoring pregabalin included less pain on a 0-10 scale on 1 day [mean difference (MD): -0.87; 95% CI: -1.55 to -0.19; P=0.01], 3 days (MD: -1.55; 95% CI: -1.93 to -1.18; P<0.00001), 1 month (MD: -1.58; 95% CI: -2.75 to -0.42; P=0.008), 3 months (MD: -1.69; 95% CI: -2.71 to -0.66; P=0.001) postoperatively, and less incidence of neuropathic pain (OR: 0.20; 95% CI: 0.05-0.91; P=0.04), less mean morphine consumption (MD: -5.03; 95% CI: -8.06 to -1.99; P=0.001), but more dizziness (OR: 3.33; 95% CI: 1.36-8.17; P=0.009), more drowsiness (OR: 8.61; 95% CI: 2.23-33.20; P=0.002), and less constipation (OR: 0.23; 95% CI: 0.09-0.59; P=0.002). There was no statistical differences in pain score on 7 days (MD:-0.77; 95% CI: -2.38 to 0.84; P=0.35), nausea (OR: 0.73; 95% CI: 0.42-1.26; P=0.26), and vomiting (OR: 0.83; 95% CI: 0.36-1.90; P=0.65).

CONCLUSION

Pregabalin can prevent postoperative pain in thoracotomy and decrease incidence of neuropathic pain and morphine consumption. Pregabalin may be a valuable asset in management of acute and persistent postoperative pain in thoracotomy.

Pregabalin to improve postoperative recovery in bariatric surgery: a parallel, randomized, double-blinded, placebo-controlled study

Purpose

Obesity has been considered as a major public health problem in developed countries for which bariatric surgery has become an important treatment strategy. Postoperative pain, however, is a frequent problem in postoperative management. Pregabalin blocks the development of hyperalgesia and central pain sensitization. The objective of this randomized, placebo-controlled, double-blinded trial was to evaluate the effect of a single dose of preoperative pregabalin vs placebo on the quality of postoperative recovery in patients undergoing bariatric surgery.

Patients and methods

A total of 70 patients undergoing abdominal gastroplasty were randomly assigned to receive oral pregabalin (75 mg) or an identical placebo 1 hour before surgery. The primary outcome was Quality of Recovery-40 (QoR-40) score at 24 hours. Secondary outcomes included opioid consumption and postoperative pain scores. P<0.05 was considered to indicate statistical significance.

Results

In all, 60 of the 70 patients completed the study. The mean (SD) global recovery scores (QoR-40) 24 hours after surgery in the pregabalin and control groups were 183.7 (9) and 182.1 (12), respectively (mean difference=1.6, 95% CI -7.36 to 4.2, P=0.59). There was no significant difference in the total opioid consumption in the 24 hours following surgery between the two groups (pregabalin vs control=0.47×0.2; mean difference=0.26, 95% CI -0.24 to 0.77, P=0.3). There were no significant differences in nausea, vomiting, or time to postanesthesia care unit discharge between the two groups.

Conclusion

In patients who underwent bariatric surgery, a single preoperative dose of pregabalin (75 mg) did not improve pain relief, quality of postoperative recovery, or reduction in opioid consumption.

Clinical trial registration

http://www.ensaiosclinicos.gov.br (identifier: RBR-2g89x8).

The analgesic effects of intraoperative total intravenous anesthesia (TIVA) with propofol versus sevoflurane after colorectal surgery

Clinical studies have shown that total intravenous anesthesia (TIVA) with propofol is associated with better postoperative pain control compared with inhalational anesthesia, while other studies have not shown any benefit. The analgesic effect of TIVA with propofol in colorectal surgery has not been studied. The aim of this study is to evaluate the postoperative analgesic effects of TIVA with propofol versus inhalational sevoflurane in colorectal surgery.This is a retrospective case-control study. Records of patients undergoing colorectal surgery from 2014 to 2016 (36 months) were retrieved. Ninety-five patients who received TIVA with propofol were matched against 95 patients who received inhalational sevoflurane. Acute postoperative numerical rating scale (NRS) pain scores, postoperative morphine consumption, patient satisfaction, and side effects were compared and analyzed for differences between TIVA with propofol and sevoflurane.There were no significant differences in NRS pain scores, incidence of side effects, and patient satisfaction between the 2 groups. Patients receiving TIVA with propofol had significantly reduced total morphine consumption (P < .001), and daily morphine consumption on postoperative days 1 (P = .031), 2 (P = .002), and 3 (P = .031) compared with those receiving sevoflurane.TIVA with propofol was not associated with improved postoperative analgesia, better patient satisfaction, or reduced side effects. It may reduce postoperative opioid consumption after colorectal surgery.

Effects of Gabapentinoids Premedication on Shoulder Pain and Rehabilitation Quality after Laparoscopic Cholecystectomy: Pregabalin versus Gabapentin

Introduction

Gabapentinoids are increasingly used in preoperative premedication despite controversial results. The aim of our study was to evaluate the effects of preemptive use of gabapentin or pregabalin on postoperative shoulder pain and rehabilitation quality after laparoscopic cholecystectomy.

Methods

This is a clinical trial comparing the effects of a preoperative premedication with 600 mg of gabapentin or 150 mg of pregabalin versus placebo on postoperative pain and recovery quality after laparoscopic cholecystectomy. Premedication was taken 2 hours before the surgery beginning. Ninety patients were included and randomized into 3 groups (gabapentin, pregabalin, and placebo). The anesthetic protocol was the same for all patients. Primary endpoint was the shoulder pain intensity at the 48th postoperative hour. Secondary endpoints were postoperative nausea and vomiting (PONV), sleep quality during the first night, and the onset time for the first standing position.

Results

During the first 48 postoperative hours, the gabapentin and pregabalin groups had significantly lower shoulder pain than the placebo group (p < 0.05). In gabapentinoids groups, the incidence of PONV was lower and the sleep quality during the first postoperative night was better with significant results. Mean Spiegel scores were 22.43 ± 1.45, 22.30 ± 1.44, and 17.17 ± 1.66, respectively, in pregabalin, gabapentin, and placebo groups (p < 0.05). The delay for the first standing position was 14.9 ± 4.9 hours in the pregabalin group, 9.7 ± 3.6 hours in the gabapentin group, and 21.6 ± 2.1 hours in the placebo group. No superiority was found between gabapentin and pregabalin.

Conclusion

Preemptive premedication with gabapentinoids can enhance postoperative rehabilitation quality after laparoscopic cholecystectomy by reducing postoperative shoulder pain, decreasing PONV incidence, and improving sleep quality during the first postoperative night. This trial is registered with ClinicalTrial.gov (NCT03241875).

Antiepileptic drugs as analgesics/adjuvants in inflammatory pain: current preclinical evidence

Inflammatory pain is the most common type of pain that is treated clinically. The use of currently available treatments (classic analgesics - NSAIDs, paracetamol and opioids) is limited by insufficient efficacy and/or side effects/tolerance development. Antiepileptic drugs (AEDs) are widely used in neuropathic pain treatment, but there is substantial preclinical evidence on their efficacy against inflammatory pain, too. In this review we focus on gabapentinoids (gabapentin and pregabalin) and dibenzazepine AEDs (carbamazepine, oxcarbazepine, and recently introduced eslicarbazepine acetate) and their potential for relieving inflammatory pain. In models of somatic, visceral and trigeminal inflammatory pain, that have a translational value for inflammatory conditions in locomotor system, viscera and head/face, AEDs have demonstrated analgesic activity. This activity was mostly consistent, dependent on the dose and largely independent on the site of inflammation and method of its induction, nociceptive stimuli, species, specific drug used, its route of administration and dosing schedule. AEDs exerted comparable efficacy with classic analgesics. Effective doses of AEDs are lower than toxic doses in animals and, when expressed as equivalent human doses, they are largely overlapping with AEDs doses already used in humans for treating epilepsy/neuropathic pain. The main mechanism of antinociceptive/antihyperalgesic action of gabapentinoids in inflammatory pain models seems to be α₂δ-dependent suppression of voltage-gated calcium channels in primary sensory neurons that leads to reduced release of neurotransmitters in the spinal/medullar dorsal horn. The suppression of NMDA receptors via co-agonist binding site primarily at spinal sites, activation of various types of K⁺ channels at spinal and peripheral sites, and activation of noradrenergic and serotonergic descending pain modulatory pathways may also contribute. Inhibition of voltage-gated sodium channels along the pain pathway is probably the main mechanism of antinociceptive/antihyperalgesic effects of dibenzazepines. The recruitment of peripheral adrenergic and purinergic mechanisms and central GABAergic mechanisms may also contribute. When co-administered with classic/other alternative analgesics, AEDs exerted synergistic/additive interactions. Reviewed data could serve as a basis for clinical studies on the efficacy/safety of AEDs as analgesics/adjuvants in patients with inflammatory pain, and contribute to the improvement of the treatment of various inflammatory pain states.

Endogenous Opiates and Behavior: 2016

This paper is the thirty-ninth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2016 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

The Effect of a Single Dose Oral Pregabalin on Hemodynamic Changes and Duration of Analgesia after Spinal Anesthesia in Orthopedic Surgeries of Tibial Fractures

Treatment of acute pain and hemodynamic changes after surgery is extremely important. Various drugs for pain relief after surgery have been studied. The aim of this study was to evaluate the effect of a single dose of oral pregabalin on hemodynamic changes and duration of analgesia after spinal anesthesia in orthopedic surgeries of tibia fractures. This clinical trial was carried out on 120 patients with fractures of the tibia bone in 2014 in city of Zahedan. Sampling was conducted using randomized blocks and patients were placed into pregabalin (150 mg PO 1 h before anesthesia) and placebo groups. Duration of analgesia, severity of anxiety, mean arterial pressure, and pulse rate were evaluated in both groups. The mean age of the patients was 34.8 ± 21.7 years and 84 patients (70%) were male and 36 (30%) were female. There were no significant differences at baseline characteristics of the patients in two arms of the study. After surgery, mean arterial pressure, pulse rate and anxiety, were significantly lower in intervention group. Also the duration of analgesia was significantly longer in intervention arm (185.3 ± 4.9 vs 36.9 ± 13.9, P < 0.01). Dizziness as a side effect of pregabalin was observed in 21 and 11 subjects in intervention and placebo groups, respectively (P < 0.01). The present study showed that a single dose of oral pregabalin increases the duration of analgesia and maintains hemodynamic stability in orthopedic surgery patients.

Is perioperative pregabalin effective for reducing postoperative pain in major surgery?

INTRODUCTION

Pregabalin is a structural analog of γ-aminobutyric acid that may have a role in acute pain management. It has been used in the perioperative context, but there is controversy regarding its real clinical utility.

METHODS

To answer this question we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach.

RESULTS AND CONCLUSIONS

We identified 21 systematic reviews including 77 randomized trials. We concluded the use of perioperative pregabalin in major surgeries probably does not produce a clinically important decrease in acute postoperative pain. Although it could decrease nausea, postoperative vomiting and opioid requirements, it also produces an increase in sedation.

Effect of preoperative pregabalin as an adjunct to a multimodal analgesic regimen in video-assisted thoracoscopic surgery: A randomized controlled trial

BACKGROUND

Depending on the type of injury, the pain mechanisms are multifactorial. Preoperative pregabalin administrations as an adjunct to a multimodal postoperative pain management strategy have been tested in various surgical settings. The purpose of current study was to evaluate the effects of preoperative pregabalin administration on postoperative pain intensity and rescue analgesic requirement following video-assisted thoracoscopic surgery (VATS).

METHODS

Sixty adult patients undergoing VATS were randomly assigned either to receive pregabalin 150 mg (Pregabalin group) or placebo (Control group) 1 hour before anesthesia. Primary efficacy variable was pain intensity. Secondary efficacy variables were the requirement of rescue analgesics, total volume of intravenous patient-controlled analgesia (IV-PCA), and adverse effects induced by pregabalin or IV-PCA.

RESULTS

Pain intensity scores at post-anesthesia care unit (PACU), 6 and 24 hours were lower significantly in the Pregabalin group compared with the Control group (mean [SD]; 5.6 [2.0] vs 6.8 [1.8]; mean difference: 1.2, 95% CI of difference: 0.2166-2.1835, P = .018, mean [SD]; 3.8 [1.9] vs 5.6 [1.4]; mean difference: 1.8, 95% CI of difference: 1.0074-2.7260, P = .001 and mean [SD]; 2.6 [1.6] vs 3.5 [1.5]; mean difference: 0.9, 95% CI of difference: 0.0946-1.7054, P = .029, respectively]. Also, the frequency of additional rescue drug administered at PACU (median [interquartile range]; 2 [2-3] vs 1 [1-2], P = .027) was significantly less in the Pregabalin group. The incidences of adverse effects related to pregabalin or IV-PCA were not different between the groups.

CONCLUSION

A single administration of pregabalin 150 mg before VATS decreased postoperative pain scores and incidence of additional rescue analgesics in the immediate postoperative period without increased risk of adverse effects.

Effects of Single-Dose Preemptive Pregabalin and Intravenous Ibuprofen on Postoperative Opioid Consumption and Acute Pain after Laparoscopic Cholecystectomy

PURPOSE

Non-opioid medications as a part of multimodal analgesia has been increasingly suggested in the management of acute post-surgical pain. The present study was planned to compare the efficacy of the combination of pregabalin plus ıv ibuprofen.

METHODS

58 patients were included in this prospective, randomized, double-blinded study. The pregabalin group (Group P, n = 29) received 150 mg pregabalin, the pregabalin plus ibuprofen group (Gropu PI, n = 29) received 150 mg pregabalin and 400mg ıv ibuprofen before surgery. Postoperative fentanyl consumption, additional analgesia requirements and PACU stay were recorded. Postoperative analgesia was performed with patient-controlled IV fentanyl.

RESULTS

VAS scores in the group PI were statistically lower at PACU, 1and 2 hours at rest, at PACU, 1, 2, 4, 12 and 24 hours on movement compared to the group P (P < 0.05). Opioid consumption was statistically significantly higher in the group P compared to the group PI (130.17 ± 60.27 vs 78.45 ± 60.40 μq, respectively, P < 0.001) and reduced in the 4th 24 hours by 55% in group PI. Rescue analgesia usage was statistically significantly higher in the group P than in the group PI (16/29 vs 7/29, respectively, P < 0.001). Four patient in the group PI did not need any opioid drug. Besides, PACU stay was shorter in the group PI than the group P (10.62 ± 2.38 vs 15.59 ± 2.11 min, respectively, P < 0.001).

CONCLUSION

Preemptive pregabalin plus ıv ibuprofen in laparoscopic cholecystectomy reduced postoperative opioid consumption. This multimodal analgesic aproach generated lower pain scores in the postoperative period.

Postoperative pain management in the postanesthesia care unit: an update

Acute postoperative pain remains a major problem, resulting in multiple undesirable outcomes if inadequately controlled. Most surgical patients spend their immediate postoperative period in the postanesthesia care unit (PACU), where pain management, being unsatisfactory and requiring improvements, affects further recovery. Recent studies on postoperative pain management in the PACU were reviewed for the advances in assessments and treatments. More objective assessments of pain being independent of patients' participation may be potentially appropriate in the PACU, including photoplethysmography-derived parameters, analgesia nociception index, skin conductance, and pupillometry, although further studies are needed to confirm their utilities. Multimodal analgesia with different analgesics and techniques has been widely used. With theoretical basis of preventing central sensitization, preventive analgesia is increasingly common. New opioids are being developed with minimization of adverse effects of traditional opioids. More intravenous nonopioid analgesics and adjuncts (such as dexmedetomidine and dexamethasone) are introduced for their opioid-sparing effects. Current evidence suggests that regional analgesic techniques are effective in the reduction of pain and stay in the PACU. Being available alternatives to epidural analgesia, perineural techniques and infiltrative techniques including wound infiltration, transversus abdominis plane block, local infiltration analgesia, and intraperitoneal administration have played a more important role for their effectiveness and safety.