Dose-related beneficial and harmful effects of gabapentin in postoperative pain management - post hoc analyses from a systematic review with meta-analyses and trial sequential analyses

Does preappointment gabapentin affect neurological examination findings? A prospective, randomized and blinded study in healthy cats

OBJECTIVES

The aim of this study was to evaluate the influence of a preappointment oral dose of gabapentin on the neurological examination of cats.

METHODS

A prospective, randomized and blinded clinical trial was conducted in 35 client-owned healthy cats. Cats were scheduled for two appointments and randomly assigned to receive either a placebo or a 100 mg gabapentin capsule prior to the second veterinary visit. A neurological examination was performed during each visit, and the results were compared between groups. Normal/abnormal response rates for each test were based on the number of cats that allowed the test to be performed.

RESULTS

Gabapentin was administered to 17 cats. Gait and postural reactions were significantly affected in the gabapentin group. Comparing the gabapentin with the placebo groups, proprioceptive ataxia was identified in 4/17 (23.5%) vs 0/18 cats (P = 0.0288); paw placement deficits were seen in 10/11 (90.9%) vs 1/4 (25%) cats; table tactile placement deficits were identified in 13/17 (76.5%) vs 0/18 cats (P <0.0001); hopping deficits were seen in 5/17 (29.4%) vs 0/16 cats (P = 0.0185); and abnormalities on wheelbarrowing and extensor postural thrust were reported in 5/17 (29.4%) vs 0/18 cats (P = 0.0129). These results had no correlation with age or dose/kg received. No significant difference was noted in the assessment of level and content of consciousness, posture, cranial nerves and spinal nerves. No significant differences were noted in test compliance or examination duration.

CONCLUSIONS AND RELEVANCE

Gabapentin significantly altered gait analyses and postural reactions in this group of healthy cats. The administration of gabapentin could lead to false-positive results and, possibly, an incorrect identification of neurological lesions. In contrast, gabapentin did not impair the assessment of cranial nerves and spinal reflexes, which can be assessed in patients receiving the drug.

Integrating mechanistic-based and classification-based concepts into perioperative pain management: an educational guide for acute pain physicians

Chronic pain begins with acute pain. Physicians tend to classify pain by duration (acute vs chronic) and mechanism (nociceptive, neuropathic and nociplastic). Although this taxonomy may facilitate diagnosis and documentation, such categories are to some degree arbitrary constructs, with significant overlap in terms of mechanisms and treatments. In clinical practice, there are myriad different definitions for chronic pain and a substantial portion of chronic pain involves mixed phenotypes. Classification of pain based on acuity and mechanisms informs management at all levels and constitutes a critical part of guidelines and treatment for chronic pain care. Yet specialty care is often siloed, with advances in understanding lagging years behind in some areas in which these developments should be at the forefront of clinical practice. For example, in perioperative pain management, enhanced recovery protocols are not standardized and tend to drive treatment without consideration of mechanisms, which in many cases may be incongruent with personalized medicine and mechanism-based treatment. In this educational document, we discuss mechanisms and classification of pain as it pertains to commonly performed surgical procedures. Our goal is to provide a clinical reference for the acute pain physician to facilitate pain management decision-making (both diagnosis and therapy) in the perioperative period.

Risk of serious adverse events associated with non-steroidal anti-inflammatory drugs in orthopaedic surgery. A protocol for a systematic review

BACKGROUND

Postoperative pain is a common condition following orthopaedic surgeries and causes prolonged hospitalisation, delayed rehabilitation and hamper the quality of life. Non-steroidal anti-inflammatory drugs (NSAIDs) are effective analgesics and anti-inflammatory mediators in the treatment of postoperative pain. The association of NSAIDs with serious adverse events may however keep some clinicians and clinical decision makers from using NSAIDs perioperatively. The evidence regarding the risks of serious adverse events following perioperative use of NSAIDs in orthopaedic surgery is sparse and needs to be assessed in a systematic review. This is a protocol for a systematic review that aims to identify the risks of serious adverse events from perioperative use of NSAIDs in orthopaedic patients.

METHODS

Our methodology is based on the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols and the eight-step assessment procedure suggested by Jakobsen and colleagues. We wish to assess if NSAIDs versus placebo, usual care or no intervention, will influence the risks of serious adverse events in patients undergoing orthopaedic surgery. We will include all randomised trials assessing the use of NSAIDs perioperatively. To identify trials we will search the Medical Literature Analysis and Retrieval System Online, Excerpta Medica database, Cochrane Central Register, Science Citation Index Expanded on Web of Science and BIOSIS. Two authors will screen the literature and extract data. We will use the 'Risk of Bias 2 tool' to assess trials. Extracted data will be analysed using RStudio and Trial Sequential Analysis. We will create a 'Summary of Findings' table in which we will present our primary and secondary outcomes. We will assess the quality of evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

DISCUSSION

This systematic review can potentially aid clinicians and clinical decision makers in the use of NSAIDs for treatment of postoperative pain following orthopaedic surgeries.

Factors Causing Delay in Discharge in Patients Eligible for Ambulatory Lumbar Fusion Surgery

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To analyze the postoperative factors that led delayed discharge in patients who would have been eligible for ambulatory lumbar fusion (ALF).

SUMMARY OF BACKGROUND DATA

Assessing postoperative inefficiencies is vital to increase the feasibility of ALF.

MATERIALS AND METHODS

Patients who underwent single-level minimally invasive transforaminal lumbar interbody fusion and would have met the eligibility criteria for ALF were included. Length of stay (LOS); time in postanesthesia recovery unit (PACU); alertness and neurological examination, and pain scores at three and six hours; type of analgesia; time to physical therapy (PT) visit; reasons for PT nonclearance; time to per-oral (PO) intake; time to voiding; time to readiness for discharge were assessed. Time taken to meet each discharge criterion was calculated. Multiple regression analyses were performed to study the effect of variables on postoperative parameters influencing discharge.

RESULTS

Of 71 patients, 4% were discharged on the same day and 69% on postoperative day 1. PT clearance was the last-met discharge criterion in 93%. Sixty-six percent did not get PT evaluation on the day of surgery. Seventy-six percent required intravenous opioids and <60% had adequate pain control. Twenty-six percent had orthostatic intolerance. The median postoperative LOS was 26.9 hours, time in PACU was 4.2 hours, time to PO intake was 6.5 hours, time to first void was 6.3 hours, time to first PT visit was 17.7 hours, time to PT clearance was 21.8 hours, and time to discharge readiness was 21.9 hours. Regression analysis showed that time to PT clearance, time to PO intake, time to voiding, time in PACU, and pain score at three hours had a significant effect on LOS.

CONCLUSIONS

Unavailability of PT, surgery after 1  pm , orthostatic intolerance, inadequate pain control, prolonged PACU stay, and long feeding and voiding times were identified as modifiable factors preventing same-day discharge.

LEVEL OF EVIDENCE

4.

Association of gabapentinoid utilization with postoperative pulmonary complications in gynecologic surgery: a retrospective cohort study

OBJECTIVE

To investigate gabapentinoid utilization and association with postoperative pulmonary complications after gynecologic surgery.

METHODS

After Institutional Review Board approval, we performed this retrospective cohort study using the Premier Healthcare Database. We used ICD-10 and charge codes to identify adults who underwent elective gynecologic surgery from 2015 to 2018 and received either gabapentin or pregabalin on the day of surgery. Our primary outcome was a composite of pulmonary complications: respiratory failure, pneumonia, reintubation, pulmonary edema, and non-invasive or invasive ventilation. Secondary outcomes included mortality, intensive care unit admission, mechanical or non-invasive ventilation, hospital length of stay, re-admission within 30 days, opioid consumption and antiemetic use. Multivariable generalized linear mixed models were utilized to examine the associations between gabapentinoids and our outcome measures, adjusted for all covariates.

RESULTS

Data from 253,013 patients were analyzed, with 19,121 (7.6%) receiving gabapentinoids. Gabapentinoid utilization increased from 3.9% in 2015 to 12.3% in 2018, and was associated with increased pulmonary complications (OR 1.19; 95% CI 1.03-1.38), non-invasive ventilation (odds ratio [OR] 1.53; 95% CI 1.29-1.81), duration of hospital stay (% change 1.75; 95% CI 0.92-2.59), daily antiemetic doses on day of surgery (mean difference [MD] 1.37; 95% CI 1.26-1.49) and subsequently (MD 1.61; 95% CI 1.30-1.99), and higher daily average (MD 4.59 mg; 95% CI 3.55-5.63) and total (MD 8.74 mg; 95% CI 6.83-10.62) parenteral morphine equivalents.

CONCLUSIONS

Gabapentinoid utilization in gynecologic surgery is increasing and is associated with postoperative pulmonary complications.

Perioperative Multimodal Analgesia Reduces Opioid Use Following Skin Grafting in Nonintubated Burn Patients

Hundreds of patients are treated for burn injuries each year at University of Wisconsin School of Medicine and Public Health. Pain management is particularly challenging during dressing changes and following skin grafting procedures. We performed a retrospective chart review from January 2011 through June 2018 to evaluate the effect of nonopioid analgesic medications on opioid use in nonintubated patients. Our primary outcome was the change in opioid use following the procedure. We found that most patients (69%) report severe pain (Numeric Rating Scale ≥7) immediately after autologous skin grafting. On average, patients required an additional 52 mg of oral morphine equivalents (ME) in the 24 h after the procedure compared with the 24 h before. The use of perioperative nonopioid analgesia varied between patients (acetaminophen 29%, gabapentin 29%, ketamine 35%, and all three 8%). Patients who received either gabapentin or a combination of acetaminophen, gabapentin, and ketamine had a smaller increase in their opioid use than patients who did not receive the medications (-25 ME, 95% confidence interval [-46, -4]; P = .018 and -47 ME, [-81, -11]; P = .010, respectively). These results support using a combination of acetaminophen, gabapentin, and ketamine for perioperative analgesia in burn patients undergoing autologous skin grafting.

Examination of the sedative and analgesic effects of gabapentin and dexmedetomidine in patients undergoing laparoscopic cholecystectomy surgery: A randomized controlled trial

Introduction:

At present, laparoscopic surgery is a very common method, especially for the removal of the gallbladder, because pain and anxiety following surgery is a major problem in surgical operations. Various studies have demonstrated the effectiveness of gabapentin and dexmedetomidine in reducing pain intensity after surgery. The present study is aimed at examining the sedative and analgesic effects of gabapentin and dexmedetomidine in patients undergoing laparoscopic cholecystectomy.

Methods:

This was a double-blinded clinical trial involving 40 patients who were candidates for laparoscopic cholecystectomy. The patients were randomly allotted in two groups of dexmedetomidine (n = 20) and gabapentin (n = 20). Then, pain intensity based on the visual analog scale (VAS) and sedation level based on the Ramsay Sedation Scale (RSS) were measured at the curtained times. As the data were not normally distributed, the Mann–Whitney U test was used to analyze the data, and the significance level was set at 0.05.

Results:

Across the follow-up points, more reduction in pain intensity was observed in the dexmedetomidine group as compared with the gabapentin group. The available dissimilarities between these two groups in pain decrement at the recovery room and 3 h after being discharged from the recovery room were not significant (P ≥ 0.414). In addition, across all the time points, there was considerable growth in sedation in the dexmedetomidine group in comparison with the gabapentin group (P < 0.024). This finding indicated that dexmedetomidine was more effective than gabapentin in creating sedation.

Conclusion:

Compared with gabapentin, dexmedetomidine leads to more pain reduction after surgery and better sedation during and after surgery.

Dose-Dependent Association of Gabapentinoids with Pulmonary Complications After Total Hip and Knee Arthroplasties

BACKGROUND

Gabapentinoids are commonly prescribed in perioperative multimodal analgesia protocols. Despite widespread use, the optimal dose to reduce opioid consumption while minimizing risks is unknown. We assessed dose-dependent effects of gabapentinoids on opioid consumption and postoperative pulmonary complications following total hip or knee arthroplasty (THA or TKA). We hypothesized that use of a gabapentinoid on the day of THA or TKA is associated with an increased risk of postoperative pulmonary complications in a dose-response fashion compared with the risk for patients who did not receive the drug.

METHODS

Using the Premier Database, we identified adults who underwent elective primary THA or TKA from 2009 to 2014. The exposure was receipt of a gabapentinoid (gabapentin or pregabalin) on the day of surgery. Gabapentin dose was categorized into 5 groups: none, 1 to 350, 351 to 700, 701 to 1,050, and >1,050 mg per day. Pregabalin dose was categorized into 4 groups: none, 1 to 110, 111 to 250, and >250 mg per day. The primary outcome was a composite of postoperative pulmonary complications, defined as respiratory failure, pneumonia, reintubation, pulmonary edema, noninvasive ventilation, or invasive mechanical ventilation.

RESULTS

Of 858,306 patients who underwent THA or TKA, 11.0% received gabapentin and 10.2% received pregabalin. The mean age (and standard deviation) of the patients was 65.6 ± 10.7 years, 39.6% were male, 78.2% were Caucasian, and 55.2% were covered by Medicare. In multilevel regression analysis, receipt of gabapentinoid at any dose on the day of surgery was associated with increased odds of postoperative pulmonary complications. Compared with no exposure to the drug being used by the particular group, all dose ranges of gabapentin and pregabalin were associated with greater odds of postoperative pulmonary complications (odds ratio, 95% confidence interval = 1.51, 1.40 to 1.63, for >1,050 mg of gabapentin and 1.81, 1.57 to 2.09, for >250 mg of pregabalin). We found no clinically meaningful associations between exposure to either gabapentin or pregabalin and perioperative opioid consumption or the length of the hospital stay.

CONCLUSIONS

Exposure to gabapentinoids at any dose on the day of THA or TKA was associated with increased odds of postoperative pulmonary complications in a dose-response fashion, with minimal effects on perioperative opioid consumption.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

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.

Perioperative gabapentin and post cesarean pain control: A systematic review and meta-analysis of randomized controlled trials

Cesarean delivery occurs in roughly one third of pregnancies. Effective postoperative pain control is a goal for patients and physicians. Limiting opioid use in this period is important as some percentage of opioid naïve individuals will develop persistent use. Gabapentin is a non-opioid medication that has been used perioperatively to improve postoperative pain and limit opioid requirements. The goal of this study is to determine the efficacy of perioperative gabapentin in improving post cesarean delivery pain control. The following data sources were searched from their inception through October 2018: MEDLINE, Ovid, ClinicalTrials.gov, Sciencedirect, and the Cochrane Library at the CENTRAL Register of Controlled Trials. A systematic review of the literature was performed to include all randomized trials examining the effect of perioperative gabapentin on post cesarean delivery pain control and other postoperative outcomes. The primary outcome was the analgesic effect of gabapentin on post cesarean delivery pain, measured by visual analog scale (VAS; 0-100) or Numerical Rating Scale (NRS; 0-10) on movement 24 hours (h) postoperative. These scores were directly compared by multiplying all NRS scores by a factor of 10. Meta-analysis was performed using the random effects model of DerSimonian and Laird, to produce summary treatment effects in terms of mean difference (MD) with 95% confidence interval (CI). Six placebo controlled trials (n = 645) were identified as relevant and included in the meta-analysis. All studies included only healthy pregnant women (American Society of Anesthesiologist (ASA) physical status I or II) undergoing spinal anesthesia for cesarean delivery at term. Participants were randomized to either 600 mg oral gabapentin or placebo preoperatively and in one study the medications were also continued postoperatively. Pooled data showed that women who received gabapentin prior to cesarean delivery had significantly lower VAS pain scores at 24 h on movement (MD -11.58, 95% CI -23.04 to -0.12). VAS pain scores at other time points at rest or on movement were not significantly different for those who received gabapentin and placebo although there was a general trend toward lower pain scores for women receiving gabapentin. There was no significant between-group difference in use of additional pain medications, supplemental opioids, and maternal or neonatal side effects. There was higher pain control satisfaction at 12 and 24 h in the gabapentin versus placebo groups.

Effects of a single dose of preoperative pregabalin and gabapentin for acute postoperative pain: a network meta-analysis of randomized controlled trials

Background

Pregabalin (PGB) and gabapentin (GBP) are current and emerging drugs in the field of pre-emptive preoperative analgesia. However, the role of PGB or GBP in acute postoperative pain management still remains elusive.

Materials and methods

We conducted a comprehensive literature search of articles published by December 3, 2017. A total of 79 randomized controlled trials with 6,201 patients receiving single-dose premedication were included. Through a network meta-analysis (NMA), we validated the analgesic effect and incidence of adverse events by using various doses of PGB or GBP administration.

Results

NMA results suggested that the analgesic effect may be dose related. For 24-hour opioid consumption, a consistent decrease was found with the increase in the dose of PGB or GBP. For 24-hour pain score at rest, a high dose (≥150 mg) of PGB was more effective in decreasing pain score than a dose of 75 mg, and a high dose (≥900 mg) of GBP reduced pain intensity than doses of 300 or 600 mg. Moreover, the incidence of adverse reactions varied with varying doses of PGB or GBP.

Conclusion

A dose-response relationship was detected in opioid consumption and postoperative pain for a single-dose preoperative administration of PGB and GBP. Making reasonable choice of drugs and dosage may prevent the occurrence of adverse reactions.