Adding gabapentin to a multimodal regimen does not reduce acute pain, opioid consumption or chronic pain after total hip arthroplasty

Efficacy of Oral Nefopam on Multimodal Analgesia in Total Knee Arthroplasty: A Prospective, Double-Blind, Placebo-Controlled, Randomized Trial

BACKGROUND

Multimodal analgesia is central to pain management after total knee arthroplasty (TKA). This study aimed to evaluate the efficacy of adding oral nefopam to multimodal analgesia for post-TKA pain management.

METHODS

In this prospective, double-blind, placebo-controlled, randomized trial, 100 patients who underwent TKA at our hospital were randomized to either the nefopam or the control group. After surgery, patients in the nefopam group received 200 mg of celecoxib, 150 mg of pregabalin, and 40 mg of nefopam twice daily to control postoperative pain. Patients in the control group received 200 mg of celecoxib, 150 mg of pregabalin, and a placebo. Oxycodone hydrochloride (10 mg) was used as the rescue analgesic. If the pain remained poorly controlled, 10 mg of morphine hydrochloride was injected subcutaneously as a secondary rescue analgesic. The primary outcome was the postoperative consumption of oxycodone and morphine as rescue analgesics. Secondary outcomes were postoperative pain assessed using the visual analogue scale (VAS), functional recovery assessed by the range of knee motion and ambulation distance, time until hospital discharge, indicators of liver function, and complication rates.

RESULTS

Patients in the nefopam group had significantly lower postoperative oxycodone and morphine consumption within 24 hours after surgery and during hospitalization, lower VAS pain scores at rest and during motion within 24 h after surgery, better functional recovery on postoperative days 1 and 2, and a shorter hospital stay. However, the absolute reduction in 0 to 24 h opioid consumption, VAS pain scores, and knee range of motion did not exceed the reported minimal clinically important difference. Both groups had similar indicators of liver function and complication rates.

CONCLUSIONS

Adding oral nefopam to multimodal analgesia resulted in statistically significant improvements in opioid consumption, VAS pain scores, and functional recovery. However, the amount of improvement may not be clinically important.

Ultrasound-guided suprainguinal fascia iliaca compartment block and early postoperative analgesia after total hip arthroplasty: a randomised controlled trial

BACKGROUND

Hip replacement surgery can be painful; postoperative analgesia is crucial for comfort and to facilitate recovery. Regional anaesthesia can reduce pain and postoperative opioid requirements. The role of ultrasound-guided suprainguinal fascia iliaca block for analgesia after elective total hip arthroplasty is not well defined. This randomised trial evaluated its analgesic efficacy.

METHODS

Consenting participants (134) scheduled for elective primary total hip arthroplasty under spinal anaesthesia were randomly allocated to receive ultrasound-guided fascia iliaca block with ropivacaine 0.5% or sham block with saline. The primary outcome was opioid consumption in the first 24 h after surgery. Additional outcomes included pain scores at 4, 8, 12, and 16 h, opioid-related side-effects (nausea, vomiting, pruritis), ability to perform physiotherapy on the first postoperative day, and physiotherapist-assessed quadriceps weakness.

RESULTS

There were no significant differences in 24-h opioid consumption (block vs sham block, mean difference -3.2 mg oral morphine equivalent, 95% confidence interval -15.3 to 8.1 mg oral morphine equivalent, P=0.55) or any other prespecified outcomes.

CONCLUSIONS

In patients undergoing primary total hip arthroplasty, ultrasound-guided suprainguinal fascia iliaca block with ropivacaine did not confer a significant opioid-sparing effect compared with sham block. There were no differences in other secondary outcomes including pain scores, opioid-related side-effects, or ability to perform physiotherapy on the first postoperative day.

CLINICAL TRIAL REGISTRATION

www.

CLINICALTRIALS

gov (NCT03069183).

Efficacy of Adding Acetaminophen to Preemptive Multimodal Analgesia in Total Knee Arthroplasty: A Double-blinded Randomized Study

OBJECTIVE

Preemptive multimodal analgesia is a frequently utilized method for controlling pain after total knee arthroplasty (TKA). So far, no studies have specifically examined the efficacy of adding acetaminophen to preemptive multimodal analgesia in TKA. The current work aimed to assess the efficacy of adding acetaminophen to preemptive multimodal analgesia for clinical pain management after TKA.

METHODS

This was a double-blinded randomized study including 80 cases randomized to the acetaminophen and control groups, respectively. The acetaminophen group was administered celecoxib at 400 mg, pregabalin at 150 mg, and acetaminophen at 300 mg 2 h before TKA. Control patients were administered celecoxib, pregabalin, and placebo. The primary outcome was postsurgical use of morphine hydrochloride for rescue analgesia. Secondary outcomes included the time to the initial rescue analgesia, postsurgical pain as determined by a visual analogue scale (VAS), functional recovery as reflected by the range of knee motion and ambulation distance, hospitalization duration, and complication rates. Continuous data with normal and skewed distributions were compared by the Student's t test and the Mann-Whitney U test, respectively. Categorical variables were compared by the Pearson's chi-squared test.

RESULTS

The control and acetaminophen groups were comparable in postoperative 0-24 h morphine consumption (11.3 ± 6.5 mg vs 12.3 ± 7.7 mg, P = 0.445) and total morphine consumption (17.3 ± 10.1 mg vs 19.3 ± 9.4 mg, P = 0.242). Additionally, time to the initial rescue analgesia, postoperative VAS score at any time point, postoperative functional recovery of the knee, and hospitalization duration were similar in both groups. Both groups also had similar occurrence rates of postoperative complications.

CONCLUSIONS

In this study, adding acetaminophen to preoperative preemptive multimodal analgesia did not decrease postoperative morphine use or ameliorate pain relief. The efficacy of adding acetaminophen to preemptive multimodal analgesia in TKA need to be further explored in future studies.

Efficacy of Opioids in Preemptive Multimodal Analgesia for Total Knee Arthroplasty: A Prospective, Double-Blind, Placebo-Controlled, Randomized Trial

BACKGROUND

Preemptive multimodal analgesia is a commonly used technique to control pain following total knee arthroplasty (TKA). This study aimed to evaluate the efficacy of pre-emptive opioids for pain management in patients who underwent TKA.

METHODS

In this prospective, double-blind, placebo-controlled, randomized trial, 100 patients who underwent TKA at our hospital were randomized to the oxycodone or control group. At 2 hours before surgery, patients in the oxycodone group received 400 mg celecoxib, 150 mg pregabalin, and 10 mg extended-release oxycodone hydrochloride. Patients in the control group received 400 mg celecoxib, 150 mg pregabalin, and placebo. The primary outcome was postoperative consumption of morphine hydrochloride as rescue analgesia. Secondary outcomes were time to first rescue analgesia, postoperative pain assessed by the visual analogue scale, functional recovery assessed by range of knee motion and ambulation distance, time until hospital discharge, indicators of liver function, and complication rates.

RESULTS

The 2 groups were similar in mean postoperative 0 to 24 hour morphine consumption (11.4 mg for control versus 12.4 mg for oxycodone group, P = .419) and mean total morphine consumption (18.2 versus 19.8 mg, P = .227). There were no statistical differences in secondary outcomes.

CONCLUSIONS

In our study, preemptive opioid administration did not provide clinical benefits over placebo. Orthopaedic surgeons should consider not using pre-operative opioids in patients undergoing TKA.

Procedure-specific acute pain trajectory after elective total hip arthroplasty: systematic review and data synthesis

BACKGROUND

For most procedures, there is insufficient evidence to guide clinicians in the optimal timing of advanced analgesic methods, which should be based on the expected time course of acute postoperative pain severity and aimed at time points where basic analgesia has proven insufficient.

METHODS

We conducted a systematic search of the literature of analgesic trials for total hip arthroplasty (THA), extracting and pooling pain scores across studies, weighted for study size. Patients were grouped according to basic anaesthetic method used (general, spinal), and adjuvant analgesic interventions such as nerve blocks, local infiltration analgesia, and multimodal analgesia. Special consideration was given to high-risk populations such as chronic pain or opioid-dependent patients.

RESULTS

We identified and analysed 71 trials with 5973 patients and constructed pain trajectories from the available pain scores. In most patients undergoing THA under general anaesthesia on a basic analgesic regimen, postoperative acute pain recedes to a mild level (<4/10) by 4 h after surgery. We note substantial variability in pain intensity even in patients subjected to similar analgesic regimens. Chronic pain or opioid-dependent patients were most often actively excluded from studies, and never analysed separately.

CONCLUSIONS

We have demonstrated that it is feasible to construct procedure-specific pain curves to guide clinicians on the timing of advanced analgesic measures. Acute intense postoperative pain after THA should have resolved by 4-6 h after surgery in most patients. However, there is a substantial gap in knowledge on the management of patients with chronic pain and opioid-dependent patients.

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

The expanding role of chronic pain interventions in multimodal perioperative pain management: a narrative review

Surgery is a risk factor for chronic pain and long-term opioid use. As perioperative pain management continues to evolve, treatment modalities traditionally used for chronic pain therapy may provide additional benefit to patients undergoing surgery. Interventions such as radiofrequency ablation, cryoneurolysis, and neuromodulation may potentially be used in conjunction with acute pain procedures such as nerve blocks and multimodal analgesia. Pharmacological agents associated with chronic pain medicine, including gabapentinoids, ketamine, and selective serotonin reuptake inhibitors, may be useful adjuncts in perioperative pain management when indicated. There may also be a role for acupuncture, music therapy, and other integrative medicine therapies. A transitional pain service can help coordinate outpatient care with inpatient perioperative pain management and promote a more personalized and comprehensive approach that can improve postoperative outcomes.

Research design considerations for chronic pain prevention clinical trials: IMMPACT recommendations

Although certain risk factors can identify individuals who are most likely to develop chronic pain, few interventions to prevent chronic pain have been identified. To facilitate the identification of preventive interventions, an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain. We present general design considerations for prevention trials in populations that are at relatively high risk for developing chronic pain. Specific design considerations included subject identification, timing and duration of treatment, outcomes, timing of assessment, and adjusting for risk factors in the analyses. We provide a detailed examination of 4 models of chronic pain prevention (ie, chronic postsurgical pain, postherpetic neuralgia, chronic low back pain, and painful chemotherapy-induced peripheral neuropathy). The issues discussed can, in many instances, be extrapolated to other chronic pain conditions. These examples were selected because they are representative models of primary and secondary prevention, reflect persistent pain resulting from multiple insults (ie, surgery, viral infection, injury, and toxic or noxious element exposure), and are chronically painful conditions that are treated with a range of interventions. Improvements in the design of chronic pain prevention trials could improve assay sensitivity and thus accelerate the identification of efficacious interventions. Such interventions would have the potential to reduce the prevalence of chronic pain in the population. Additionally, standardization of outcomes in prevention clinical trials will facilitate meta-analyses and systematic reviews and improve detection of preventive strategies emerging from clinical trials.

The Efficacy and Safety of Gabapentinoids in Total Joint Arthroplasty: Systematic Review and Direct Meta-Analysis

BACKGROUND

Gabapentinoids are commonly used as an adjunct to traditional pain management strategies after total joint arthroplasty (TJA). The purpose of this study is to evaluate the efficacy and safety of gabapentinoids in primary TJA to support the combined clinical practice guidelines of the American Association of Hip and Knee Surgeons, American Academy of Orthopaedic Surgeons, Hip Society, Knee Society, and the American Society of Regional Anesthesia and Pain Management.

METHODS

The MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were searched for studies published prior to November 2018 on gabapentinoids in TJA. All included studies underwent qualitative and quantitative homogeneity testing followed by a systematic review and direct comparison meta-analysis to assess the efficacy and safety of gabapentinoids.

RESULTS

In total, 384 publications were critically appraised to provide 13 high-quality studies regarded as the best available evidence for analysis. In the perioperative period prior to discharge, pregabalin reduces postoperative opioid consumption, but gabapentinoids do not reduce postoperative pain. After discharge, gabapentin does not reduce postoperative pain or opioid consumption, but pregabalin reduces both postoperative pain and opioid consumption.

CONCLUSION

Moderate evidence supports the use of pregabalin in TJA to reduce postoperative pain and opioid consumption. Gabapentinoids should be used with caution, however, as they may lead to an increased risk of sedation and respiratory depression especially when combined with other central nervous system depressants such as opioids.

The efficacy of perioperative gabapentin for the treatment of postoperative pain following total knee and hip arthroplasty: a meta-analysis

Background

Postoperative pain after total knee arthroplasty (TKA) and total hip arthroplasty (THA) influence patients’ rehabilitation and life quality. Although gabapentin has been widely used for analgesia, its efficacy is still controversial in TKA and THA. This meta-analysis was performed to assess the efficacy and safety of gabapentin following TKA and THA.

Method

Electronic databases including PubMed, EMBASE, Cochrane Central Register of Controlled Trials, MEDLINE, and ClinicalTrials.gov were comprehensively retrieved for randomized controlled trials from their inception to June 2019. A total of 7 studies, which compared the administration of gabapentin with that of placebo for the treatment of postoperative pain, were included in our meta-analysis. The meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

Result

There was no difference in pain score at 24 (P = 0.87), 48 (P = 0.15), and 72 (P = 0.85) h associated with the use of gabapentin. Likewise, no difference in accumulative morphine consumption at 48 h following TKA or THA was found between gabapentin and placebo (DM = − 8.14, 95% CI − 18.55 to 2.28, P = 0.13). The incidence of opioid-related adverse effects, including nausea, pruritus, sedation, and dizziness, is no difference between gabapentin and placebo group. However, subgroup analysis indicated that gabapentin could reduce the incidence of pruritus after TKA (RR = 0.35, 95% CI 0.12 to 0.99, P = 0.05).

Conclusion

Based on our meta-analysis, gabapentin did not decrease postoperative pain, cumulative morphine consumption, and the incidence of adverse effects after TKA and THA. There was not enough evidence to support the administrations of gabapentin for postoperative pain after TKA and THA.

Preemptive Analgesia With Oxycodone Is Associated With More Pain Following Total Joint Arthroplasty

BACKGROUND

Preemptive multimodal analgesia (PMA) is a commonly used technique to control pain following total joint arthroplasty. PMA protocols use multiple analgesics immediately preoperatively to prevent central sensitization and amplification of pain during surgery. While benefits of some individual components of a PMA protocol have been established, there are little data to support inclusion or exclusion of opioids in this context.

METHODS

This is a retrospective cohort study of 550 patients undergoing elective, primary total joint arthroplasty at a single institution using a standardized preoperative perioperative protocol. Two hundred seventy-five patients received oxycodone in addition to a standard multimodal preoperative analgesia regimen just before surgery and were compared to a matched cohort of 275 patients who received the standard regimen alone. Outcome measures included inpatient visual analog scale pain scores, inpatient opioid consumption, length of stay, and ambulation distance with physical therapy.

RESULTS

Patients who received opioids in preoperative holding reported significantly greater visual analog scale pain scores on postoperative day 1 (3.7 vs 3.1; P = .01), when compared to those who did not. These patients also walked shorter distances on postoperative day 0 (59.5' vs 125.7'; P < .001) and consumed greater morphine equivalents per hospital day over the course of their hospital stay (52.2 vs 37.2 mg; P < .001). These differences remained significant when stratified by procedure, total knee arthroplasty or total hip arthroplasty. Differences in pain and function between groups were more pronounced in patients undergoing total hip arthroplasty than those undergoing total knee arthroplasty.

CONCLUSION

Total joint patients who were given preemptive opioids immediately before surgery experienced more pain, consumed more postoperative opioids, and exhibited impaired early function as compared to those who were not given preemptive opioids. Orthopedic surgeons should reconsider routine use of preemptive opioids in this context.

Antimicrobial effect of anesthetic-eluting ultra-high molecular weight polyethylene for post-arthroplasty antibacterial prophylaxis

Despite being a relatively safe surgery, total joint replacement is often associated with two major complications-severe post-operative pain and periprosthetic joint infection. Local sustained delivery of therapeutics to the surgical site has a potential to address these complications more effectively than current clinical approaches. Given that several analgesics were shown to possess antibacterial activity, we propose here to use analgesic-loaded ultra-high molecular weight polyethylene (UHMWPE) as a delivery vehicle to provide antimicrobial effect after an arthroplasty. Three commonly used anesthetics, lidocaine, bupivacaine, and ropivacaine, were analyzed in order to reveal the drug with the highest antibacterial activity against methicillin-sensitive Staphylococcus aureus. Having shown highest antibacterial activity in the bacterial susceptibility tests, bupivacaine was chosen to be incorporated into UHMWPE to provide antibacterial properties. Bupivacaine-loaded UHMWPE possessed moderate dose-dependent antimicrobial properties, decreasing the S. aureus proliferation rate by up to 70%. Biofilm formation was also substanitally inhibited during the first 9 h of culture as quantified by bacterial counts and SEM. This proof-of-concept study is first of its kind to demonstrate that analgesic-loaded UHMWPE can be used as part of a multimodal antimicrobial therapy. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Regional and Multimodal Analgesia to Reduce Opioid Use After Total Joint Arthroplasty: A Narrative Review

BACKGROUND

Elective total joint arthroplasty may be a gateway to long-term opioid use.

QUESTIONS/PURPOSE

We sought to review the literature on multimodal and regional analgesia as a strategy to minimize perioperative opioid use and control pain in patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA).

METHODS

We conducted a narrative review to assess the state of the evidence informing opioid-sparing analgesics for THA and TKA. A PubMed search was conducted for English-language articles published before April 2018. We preferentially included well-designed randomized controlled trials, systematic reviews, and meta-analyses. Where the highest levels of evidence were not yet apparent, we evaluated retrospective and/or observational studies.

RESULTS

Multimodal analgesia emphasizing nonsteroidal anti-inflammatory agents and acetaminophen is associated with decreases in perioperative opioid use for THA and TKA. Regional analgesia, including peripheral nerve blocks and local infiltration analgesia, is also associated with decreased perioperative opioid use for THA and TKA. Emerging topics in post-arthroplasty analgesia include (1) the value of nonsteroidal anti-inflammatory drugs, (2) the use of peripheral nerve catheters and extended-release local anesthetics to prolong the duration of opioid-free analgesia, and (3) novel peripheral nerve blocks, exemplified by the IPACK (interspace between the popliteal artery and posterior capsule of the knee) block for TKA.

CONCLUSIONS

The use of multimodal analgesia with regional techniques may decrease perioperative opioid use for patients undergoing THA and TKA. These techniques should be part of a comprehensive perioperative plan to promote adequate analgesia while minimizing overall opioid exposure.

Gabapentin as an Adjunct to Standard Postoperative Pain Management Protocol in Lower Extremity Surgery

Postoperative pain is a problem that plagues physicians and has since the dawn of the surgical arts. Many interventions are available and used as the standard such as preoperative local anesthetic blocks, opiates, both oral and intravenous, and nonsteroidal antiinflammatory drugs. Although the temptation often exists to increase the postoperative opiate dose, opiate abuse is an increasing problem. This abuse has fueled the search for nonopiate pain adjuncts. Gabapentinoids have been shown to both decrease postoperative pain and, secondarily, decrease opiate dependence. This is a growing field in medical research, although it is relatively lacking in the specialty of lower extremity orthopedic surgery. A PubMed query was performed for related articles, which found only 8 related to lower extremity orthopedic surgery, and of these, none addressed the foot or ankle. Studies involving chronic pain, nonorthopedic surgery, orthopedic procedures proximal to and including the hip, studies involving only pregabalin, and studies regarding cancer pain were excluded. The results from our literature review are encouraging regarding the addition of gabapentin as a regular, perioperative adjunctive pain medication because all studied reported data evaluating preoperative administration have shown a statistically significant reduction in postoperative pain and opiate consumption.

Novel multimodal analgesia regimen improves post-TACE pain in patients with hepatocellular carcinoma

BACKGROUD

Transarterial chemoembolization (TACE) is the primary palliative treatment for patients with unresectable hepatocellular carcinoma (HCC). However, it is often accompanied by postoperative pain which hinder patient recovery. This study was to examine whether preemptive parecoxib and sufentanil-based patient controlled analgesia (PCA) could improve the pain management in patients receiving TACE for inoperable HCC.

METHODS

From June to December 2016, 84 HCC patients undergoing TACE procedure were enrolled. Because of the willingness of the individuals, it is difficult to randomize the patients to different groups. We matched the patients' age, gender and pain scores, and divided the patients into the multimodal group (n = 42) and control group (n = 42). Patients in the multimodal group received 40 mg of parecoxib, 30 min before TACE, followed by 48 h of sufentanil-based PCA. Patients in the control group received a routine analgesic regimen, i.e., 5 mg of dezocine during operation, and 100 mg of tramadol or equivalent intravenous opioid according to patient's complaints and pain intensity. Postoperative pain intensity, percentage of patients as per the pain category, adverse reaction, duration of hospital stay, cost-effectiveness, and patient's satisfaction were all taken into consideration when evaluated.

RESULTS

Compared to the control group, the visual analogue scale scores for pain intensity was significantly lower at 2, 4, 6, and 12 h (all P < 0.05) in the multimodal group and a noticeably lower prevalence of post-operative nausea and vomiting in the multimodal group (31.0% vs. 59.5%). Patient's satisfaction in the multimodal group was also significantly higher than that in the control group (95.2% vs. 69.0%). No significant difference was observed in the duration of hospital stay between the two groups.

CONCLUSION

Preemptive parecoxib and sufentanil-based multimodal analgesia regime is a safe, efficient and cost-effective regimen for postoperative pain control in HCC patients undergoing TACE.

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.

The efficacy and safety of first-line therapies for preventing chronic post-surgical pain: a network meta-analysis

Background

Due to conflicting evidence regarding first-line therapies for chronic post-surgical pain (CPSP), here we comparatively evaluated the efficacy and safety of first-line therapies for the prevention of CPSP.

Materials and Methods

MEDLINE, EMBASE, and Cochrane CENTRAL databases were searched for randomized, controlled trials (RCTs) of systemic drugs measuring pain three months or more post-surgery. Pairwise meta-analyses (a frequentist technique directly comparing each intervention against placebo) and network meta-analyses (a Bayesian technique simultaneously comparing several interventions via an evidence network) compared the mean differences for primary efficacy (reduction in all pain), secondary efficacy (reduction in moderate or severe pain), and primary safety (drop-out rate from treatment-related adverse effects). Ranking probabilities from the network meta-analysis were transformed using surface under the cumulative ranking analysis (SUCRA). Sensitivity analyses evaluated the impact of age, gender, surgery type, and outlier studies.

Results

Twenty-four RCTs were included. Mexiletine and ketamine ranked highest in primary efficacy, while ketamine and nefopam ranked highest in secondary efficacy. Simultaneous SUCRA-based rankings of the interventions according to both efficacy and safety revealed that nefopam and mexiletine ranked highest in preventing CPSP. Through the sensitivity analyses, gabapentin and ketamine remained the most-highly-ranked in terms of efficacy, while nefopam and ketamine remained the most-highly-ranked in terms of safety.

Conclusions

Nefopam and mexiletine may be considered as first-line therapies for the prevention of CPSP. On account of the paucity of evidence available on nefopam and mexiletine, gabapentin and ketamine may also be considered. Venlafaxine is not recommended for the prevention of CPSP.

Perioperative pain management following total joint arthroplasty: A review and update to an institutional pain protocol

As the rate of total joint arthroplasty increases with the aging population of the United States, new focus on decreasing opioid use through the development of multimodal pain regimens (MPRs) is becoming an important area of research. MPRs use different agents and modes of delivery in order to synergistically address pain at many levels of the pain pathway. MPRs include a combination of acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), gabapentinoids, opioids (short- and long-acting), spinal/epidural analgesia, regional nerve blocks, and local anesthetics. This review summarizes the available literature on major components of MPRs shown to be effective in the total joint arthroplasty population. Finally, the authors' preferred method for pain control in the TJA population is reviewed.

A comparison of early and late treatments on allodynia and its chronification in experimental neuropathic pain

Background Surgeries causing nerve injury can result in chronic neuropathic pain, which is clinically managed by using antidepressant or anticonvulsant drugs. Currently, there is a growing interest for investigating preemptive treatments that would prevent this long-term development of neuropathic pain. Our aim was to compare analgesic drugs using two distinct treatment modalities: either treatment onset at surgery time or following a couple of weeks of neuropathic pain. Methods In male C57BL/6J mice, neuropathic pain was induced by cuffing the sciatic nerve, and allodynia was assessed using von Frey filaments. We tested the effect of anticonvulsants (gabapentin 10 mg/kg and carbamazepine 40 mg/kg), antidepressants (desipramine 5 mg/kg, duloxetine 10 mg/kg, and fluoxetine 10 mg/kg), dexamethasone (2 mg/kg), and ketamine (15 mg/kg). Drugs were injected daily or twice a day, starting either at surgery time or on day 25 postsurgery (15 days of treatment for antidepressants and 10 days for other drugs). Results Ketamine was the only effective treatment during the early postsurgical period. Although early anticonvulsant treatment was not immediately effective, it prevented chronification of allodynia. When treatments started at day 25 postsurgery, desipramine, duloxetine, and anticonvulsants suppressed the mechanical allodynia. Conclusions Our data show that allodynia measured in experimental neuropathic pain model likely results from a combination of different processes (early vs. late allodynia) that display different sensitivity to treatments. We also propose that early anticonvulsant treatment with gabapentin or carbamazepine may have a prophylactic effect on the chronification of allodynia following nerve injury.

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

Background

During the last 15 years, gabapentin has become an established component of postoperative pain treatment. Gabapentin has been employed in a wide range of doses, but little is known about the optimal dose, providing the best balance between benefit and harm. This systematic review with meta-analyses aimed to explore the beneficial and harmful effects of various doses of gabapentin administered to surgical patients.

Materials and methods

Data in this paper were derived from an original review, and the subgroup analyses were predefined in an International Prospective Register of Systematic Reviews published protocol: PROSPERO (ID: CRD42013006538). The methods followed Cochrane guidelines. The Cochrane Library’s CENTRAL, PubMed, EMBASE, Science Citation Index Expanded, Google Scholar, and FDA database were searched for relevant trials. Randomized clinical trials comparing gabapentin versus placebo were included. Four different dose intervals were investigated: 0–350, 351–700, 701–1050, and >1050 mg. Primary co-outcomes were 24-hour morphine consumption and serious adverse events (SAEs), with emphasis put on trials with low risk of bias.

Results

One hundred and twenty-two randomized clinical trials, with 8466 patients, were included. Sixteen were overall low risk of bias. No consistent increase in morphine-sparing effect was observed with increasing doses of gabapentin from the trials with low risk of bias. Analyzing all trials, the smallest and the highest dose subgroups demonstrated numerically the most prominent reduction in morphine consumption. Twenty-seven trials reported 72 SAEs, of which 83% were reported in the >1050 mg subgroup. No systematic increase in SAEs was observed with increasing doses of gabapentin.

Conclusion

Data were sparse, and the small number of trials with low risk of bias is a major limitation for firm conclusions. Taking these limitations into account, we were not able to demonstrate a clear relationship between the dosage of gabapentin and opioid-sparing or harmful effects. These subgroup analyses are exploratory and hypothesis-generating for future trialists.

Multimodal Pain Management in Older Elective Arthroplasty Patients

BACKGROUND

Pain management after elective arthroplasty in older adults is complicated due to the risk of undertreatment of postoperative pain and potential adverse effects from analgesics, notably opioids. Using combinations of analgesics has been proposed as potentially beneficial to achieve pain control with lower opioid doses.

OBJECTIVE

We compared a multimodal pain protocol with a traditional one, in older elective arthroplasty patients, measuring self-rated pain, incidence of postoperative delirium, quantity and cost of opioid analgesics consumed.

METHODS

One hundred fifty-eight patients, 70 years and older, admitted to tertiary care for elective arthroplasty were prospectively assessed postoperative days 1-3. Patients received either traditional postoperative analgesia (acetaminophen plus opioids) or a multimodal pain protocol (acetaminophen, opioids, gabapentin, celecoxib), depending on surgeon preference. Self-rated pain, postoperative delirium, and time to achieve standby-assist ambulation were compared, as were total opioid doses and analgesic costs.

RESULTS

Despite receiving significantly more opioid analgesics (traditional: 166.4 mg morphine-equivalents; multimodal: 442 mg morphine equivalents; t = 10.64, P < .0001), there was no difference in self-rated pain, delirium, or mobility on postoperative days 1-3. Costs were significantly higher in the multimodal group (t = 9.15, P < .0001). Knee arthroplasty was associated with higher pain scores than hip arthroplasty, with no significant difference in opioid usage.

CONCLUSION

A multimodal approach to pain control demonstrated no benefit over traditional postoperative analgesia in elective arthroplasty patients, but with significantly higher amounts of opioid consumed. This poses a potential risk regarding tolerability in frail older adults and results in increased drug costs.

Gabapentin in procedure-specific postoperative pain management - preplanned subgroup analyses from a systematic review with meta-analyses and trial sequential analyses

Background

It has been argued that postoperative pain treatment should be “procedure-specific”, since different analgesics may have specific effects dependent on the surgical procedure. The aim of the present subgroup analysis was to compare the beneficial and harmful effects of perioperative gabapentin treatment in different surgical procedures.

Methods

Relevant databases were searched for randomized clinical trials (RCTs) comparing gabapentin versus placebo. Two authors independently screened titles and abstracts, extracted data and assessed risk of bias. The primary outcomes were differences in 24-h morphine consumption, and serious adverse events (SAE) between surgical procedures. These subgroup analyses were predefined in a PRISMA compliant systematic review registered at PROSPERO (ID: CRD42013006538). It was predefined that conclusions should primarily be based on trials classified as overall low risk of bias.

Results

Seventy-four RCTs with 5645 patients were included, assessing benefit and harm in cholecystectomy, hysterectomy, mastectomy, and arthroplasty surgery, spinal surgery, and thoracic surgery.

Only eight of 74 trials were classified as overall low risk of bias limiting our ability to conclude on the estimates in most meta-analyses. The differences between surgical procedures in these trials were not statistically significant when tested for subgroup differences. Fifteen trials with 1377 patients reported a total of 59 SAEs, most of which were observed in the thoracic surgery group.

Conclusion

Both beneficial and harmful effects in these subgroup analyses were influenced by bias and insufficient data, limiting conclusions. With these limitations, we could not adequately test for differences in beneficial or harmful outcomes between six surgical subgroups undergoing perioperative gabapentin treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-017-0373-8) contains supplementary material, which is available to authorized users.

Low-dose dexamethasone during arthroplasty: What do we know about the risks?

Dexamethasone is commonly applied during arthroplasty to control post-operative nausea and vomiting (PONV). However, conflicting views of orthopaedic surgeons and anaesthesiologists regarding the use of dexamethasone raise questions about risks of impaired wound healing and surgical site infections (SSI).

The aim of this systematic review is to determine the level of evidence for the safety of a peri-operative single low dose of dexamethasone in hip and knee arthroplasty.

We systematically reviewed literature in PubMed, EMBASE and Cochrane databases and cited references in articles found in the initial search from 1980 to 2013 based on predefined inclusion criteria. The review was completed with a ‘pro’ and ‘con’ discussion.

After identifying 11 studies out of 104, only eight studies met the inclusion criteria. In total, 1335 patients were studied without any incidence of SSI. Causes of SSI are multifactorial. Therefore, 27 205 patients would be required (power = 90%, alpha = 0.05) to provide substantiated conclusions on safety of a single low dose of dexamethasone.

Positively, many studies demonstrated showed convincing effects of low-dose dexamethasone on prevention of PONV and dose-dependent effects on post-operative pain and quality of recovery. Dexamethasone induces hyperglycaemia, but none of the studies demonstrated a concomitant SSI.

Conversely, animal studies showed that high dose dexamethasone inhibits wound healing.

A team approach of anaesthesiologists and orthopaedic surgeons is mandatory in order to balance the risk–benefit ratio of peri-operatively applied steroids for individual arthroplasty patients.

We did not find evidence that a single low dose of dexamethasone contributes to SSI or wound healing impairment from the current studies.

Cite this article: Wegener JT, Kraal T, Stevens MF, Hollman MW, Kerkhoffs GMMJ, Haverkamp D. Low-dose dexamethasone during arthroplasty: what do we know about the risks? EFORT Open Rev 2016;1:303-309. DOI: 10.1302/2058-5241.1.000039.

Gabapentin Does Not Appear to Improve Postoperative Pain and Sleep Patterns in Patients Who Concomitantly Receive Regional Anesthesia for Lower Extremity Orthopedic Surgery: A Randomized Control Trial

In recent years, gabapentin has gained popularity as an adjuvant therapy for the treatment of postoperative pain. Numerous studies have shown a decrease in pain score, even with immediate postoperative activity, which is significant for early post-op ambulation and regaining functionality sooner. However, studies have been in conclusive in patients undergoing lower extremity orthopedic surgery. For this reason, we hoped to study the effect of gabapentin on postoperative pain in patients undergoing total knee arthroplasty, total hip arthroplasty, or a hip fracture repair. This was done in the setting of ensuring adequate postoperative analgesia with regional blocks and opioid PCA, as is protocol at our institution. Given the sedative effects of gabapentin and the potential for improving postoperative sleep patterns, we also studied the drug's effect on this aspect of our patient's postoperative course. We utilized the Pittsburg Sleep Quality Index and Visual Analog Scale for pain to obtain a more objective standardized score amongst our study population. Our results indicate that gabapentin does not offer any additional relief in pain or improve sleep habits in patients who have received either a femoral or lumbar plexus block for lower extremity orthopedic surgery. This trial is registered with NCT01546857.

Multimodal Analgesia, Current Concepts, and Acute Pain Considerations

PURPOSE OF REVIEW

Management of acute pain following surgery using a multimodal approach is recommended by the American Society of Anesthesiologists whenever possible. In addition to opioids, drugs with differing mechanisms of actions target pain pathways resulting in additive and/or synergistic effects. Some of these agents include alpha 2 agonists, NMDA receptor antagonists, gabapentinoids, dexamethasone, NSAIDs, acetaminophen, and duloxetine.

RECENT FINDINGS

Alpha 2 agonists have been shown to have opioid-sparing effects, but can cause hypotension and bradycardia and must be taken into consideration when administered. Acetaminophen is commonly used in a multimodal approach, with recent evidence lacking for the use of IV over oral formulations in patients able to take medications by mouth. Studies involving gabapentinoids have been mixed with some showing benefit; however, future large randomized controlled trials are needed. Ketamine is known to have powerful analgesic effects and, when combined with magnesium and other agents, may have a synergistic effect. Dexamethasone reduces postoperative nausea and vomiting and has been demonstrated to be an effective adjunct in multimodal analgesia. The serotonin-norepinephrine reuptake inhibitor, duloxetine, is a novel agent, but studies are limited and further evidence is needed. Overall, a multimodal analgesic approach should be used when treating postoperative pain, as it can potentially reduce side effects and provide the benefit of treating pain through different cellular pathways.

Gabapentin for post-operative pain management - a systematic review with meta-analyses and trial sequential analyses

BACKGROUND

Perioperative pain treatment often consist of combinations of non-opioid and opioid analgesics, 'multimodal analgesia', in which gabapentin is currently used. The aim was to document beneficial and harmful effects of perioperative gabapentin treatment.

METHODS

Randomized clinical trials comparing gabapentin vs. placebo or active placebo in adult surgical patients receiving gabapentin perioperatively were included. This review was conducted using Cochrane standards, trial sequential analysis (TSA), and Grading of Recommendations Assessment, Development, and Evaluation (GRADE). The primary outcomes were 24-h opioid consumption and incidence of serious adverse events (SAE).

RESULTS

One hundred and thirty-two trials with 9498 patients were included. Thirteen trials with low risk of bias reported a reduction in 24-h opioid consumption of 3.1 mg [0.5, 5.6] [corrected]. In the analysis of gabapentin as add-on analgesic to another non-opioid analgesic regimen found a mean reduction in 24-h morphine consumption of 1.2 mg [-0.3, 2.6; TSA-adjusted CI: -0.3, 2.6] in trials with low risk of bias. [corrected]. Nine trials with low risk of bias reported a risk ratio of SAEs of 1.61 [0.91; 2.86; TSA-adjusted CI: 0.57, 4.57].

CONCLUSION

Based on GRADE assessment of the primary outcomes in trials with low risk of bias, the results are low or very low quality of evidence due to imprecision, inconsistency, and in some outcomes indirectness. Firm evidence for use of gabapentin is lacking as clinically relevant beneficial effect of gabapentin may be absent and harm is imminent, especially when added to multimodal analgesia.

The efficacy of preoperative administration of gabapentin/pregabalin in improving pain after total hip arthroplasty: a meta-analysis

Background

The purpose of this systematic review and meta-analysis of randomised controlled trials (RCTs) was to evaluate the pain control by gabapentin or pregabalin administration versus placebo after total hip arthroplasty (THA).

Methods

In January 2016, a systematic computer-based search was conducted in the Medline, Embase, PubMed, CENTRAL (Cochrane Controlled Trials Register), Web of Science and Google databases. This systematic review and meta-analysis were performed according to the PRISMA statement criteria. The primary endpoint was the cumulative morphine consumption and visual analogue scale (VAS) scores at 24 and 48 h with rest or mobilisation. The complications of vomiting, nausea, dizziness and pruritus were also compiled to assess the safety of gabapentin and pregabalin. Stata 12.0 software was used for the meta-analysis. After testing for publication bias and heterogeneity across studies, the data were aggregated for random-effects modelling when necessary.

Results

Seven studies involving 769 patients met the inclusion criteria. The meta-analysis revealed that treatment with gabapentin or pregabalin can decrease the cumulative morphine consumption at 24 h (mean difference (MD) = −7.82; 95 % CI −0.95 to −0.52; P < 0.001) and 48 h (MD = −6.90; 95 % CI −0.95 to −0.57; P = 0.118). Gabapentin or pregabalin produced no better outcome than placebo in terms of VAS score with rest at 24 h (SMD = 0.15; 95 % CI −0.17 to −0.48; P = 0.360) and with rest at 48 h (SMD = 0.22; 95 % CI −0.25 to 0.69; P = 0.363). There was no statistically significant difference between the groups with respect to the VAS score at 24 h postoperatively (SMD = 0.46; 95 % CI −0.19 to 1.11; P = 0.164) and at 48 h postoperatively (SMD = 1.15; 95 % CI −0.58 to 2.89; P = 0.193). Gabapentin decreased the occurrence of nausea (relative risk (RR), 0.49; 95 % CI 0.27–0.92, P = 0.025), but there was no significant difference in the incidence of vomiting, dizziness and pruritus.

Conclusions

On the basis of the current meta-analysis, gabapentin or pregabalin can decrease the cumulative morphine consumption and decrease the occurrence of nausea; however, further trials are needed to assess the efficacy of pain control by gabapentin or pregabalin.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-016-1231-4) contains supplementary material, which is available to authorized users.

A Meta-Analysis on the Use of Gabapentinoids for the Treatment of Acute Postoperative Pain Following Total Knee Arthroplasty

BACKGROUND

Total knee arthroplasty is a painful procedure, with approximately half of patients reporting severe pain during the early postoperative period. Gabapentinoids are used as an adjunct for the management of acute pain in approximately half of enhanced recovery programs. We performed a meta-analysis to assess the effectiveness and safety of gabapentinoids for the treatment of acute postoperative pain following total knee arthroplasty.

METHODS

Randomized controlled trials of patients undergoing elective primary total knee arthroplasty that compared the use of the gabapentinoid class of drugs (gabapentin [Neurontin; Pfizer]) or pregabalin [Lyrica; Pfizer]) with that of placebo were retrieved, with 12 studies meeting inclusion criteria. The primary outcome was pain intensity with activity at 48 hours following the surgical procedure. The secondary outcomes included pain intensity at other time points, opioid consumption, knee function, incidence of chronic pain, and adverse events.

RESULTS

No difference in pain score at 12, 24, 48, or 72 hours following the surgical procedure was seen between gabapentin and placebo. Although pregabalin was associated with reduced pain scores at 24 and 48 hours, this corresponded to a reduction of 0.5 point (95% confidence interval, 0 to 1.0 point) at 24 hours and 0.3 point (95% confidence interval, 0 to 0.6 point) at 48 hours on an 11-point numeric rating scale, which was assessed as not clinically important. Overall, no clinically relevant reduction in pain scores was associated with the use of gabapentinoids. Likewise, gabapentinoids were associated with a small, but not clinically important, reduction in cumulative opioid consumption at 48 hours (mean difference, -23.2 mg [95% confidence interval, -40.9 to -5.4 mg]). There was no difference in knee flexion at 48 hours (p = 0.63) or in the incidence of chronic pain at 3 months (p = 0.31) or 6 months (p = 0.54) associated with the use of gabapentinoids. Although gabapentinoids were associated with a significant reduction in the incidence of nausea (risk ratio, 0.7 [95% confidence interval, 0.6 to 0.9]; p < 0.001), pregabalin was also associated with a significant, clinically relevant increase in the risk of sedation (risk ratio, 1.4 [95% confidence interval, 1.1 to 1.9]; p = 0.02).

CONCLUSIONS

On the basis of this meta-analysis, we found no evidence to support the routine use of gabapentinoids in the management of acute pain following total knee arthroplasty.

LEVEL OF EVIDENCE

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

The Effect of Preoperative Gabapentin on Postoperative Nausea and Vomiting: A Meta-Analysis

BACKGROUND

Preoperative gabapentin has been shown to improve postoperative pain and limit reliance on opioid analgesia. On the basis of an alternative mechanism, our group investigated the ability of preoperative gabapentin to prevent postoperative nausea and vomiting (PONV).

METHODS

We performed a meta-analysis of trials that reported outcomes on the effect of preoperative gabapentin on PONV end points in patients undergoing general anesthesia. In our primary analysis, we calculated the pooled antiemetic effects of preoperative gabapentin in studies with PONV as the primary end point. In our secondary analysis, we calculated the pooled effects in trials involving preoperative gabapentin that reported on the side effects, nausea and vomiting.

RESULTS

Among the trials designed with PONV as a primary end point (8 trials; n = 838), preoperative gabapentin was associated with a significant reduction in PONV (risk ratio [RR] = 0.60; 99% confidence interval [CI], 0.50-0.72; P < 0.0001), nausea (RR = 0.34; 99% CI, 0.20-0.56; P < 0.0001), and vomiting (RR = 0.34; 99% CI, 0.19-0.61; P = 0.0002) at 24 hours. Among all included trials (44 trials; n = 3489) that reported on the side effects, nausea and vomiting, similar reductions were noted in PONV with preoperative gabapentin administration. Subgroup analysis of trials excluding repeat dosing, thiopental induction, and nitrous oxide maintenance and including high-risk surgery resulted in similar PONV efficacy. Preoperative gabapentin is also associated with significantly increased rates of postoperative sedation (RR = 1.22; 95% CI, 1.02-1.47; P = 0.03) compared with control.

CONCLUSIONS

Preoperative gabapentin is associated with a significant reduction in PONV among studies designed to investigate this end point. Preoperative gabapentin should be considered not only as part of a multimodal approach to postoperative analgesia, but also for prevention of PONV.

The use of gabapentin in the management of postoperative pain after total hip arthroplasty: a meta-analysis of randomised controlled trials

Background

Pain management after total hip arthroplasty (THA) varies and has been widely studied in recent years. Gabapentin as a third-generation antiepileptic drug that selectively affects the nociceptive process has been used for pain relief after THA. This meta-analysis was conducted to examine the efficacy of gabapentin in THA.

Methods

An electronic-based search was conducted using the following databases: PubMed, EMBASE, Ovid MEDLINE, ClinicalTrials.gov, and Cochrane Central Register of Controlled Trials (CENTRAL). Randomised controlled trials (RCTs) involving gabapentin and a placebo for THA were included. The meta-analysis was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results

Five trials met the inclusion criteria. The cumulative narcotic consumption and the visual analogue scale (VAS) scores at 24 and 48 h postoperatively were used for postoperative pain assessment. There was a significant decrease in morphine consumption at 24 h (P = 0.00). Compared with the control group, the VAS score (at rest) at 48 h was less in the gabapentin group (P = 0.00).

Conclusion

The administration of gabapentin is effective in decreasing postoperative narcotic consumption and the VAS score.

Research design considerations for chronic pain prevention clinical trials: IMMPACT recommendations

Although certain risk factors can identify individuals who are most likely to develop chronic pain, few interventions to prevent chronic pain have been identified. To facilitate the identification of preventive interventions, an IMMPACT meeting was convened to discuss research design considerations for clinical trials investigating the prevention of chronic pain. We present general design considerations for prevention trials in populations that are at relatively high risk for developing chronic pain. Specific design considerations included subject identification, timing and duration of treatment, outcomes, timing of assessment, and adjusting for risk factors in the analyses. We provide a detailed examination of 4 models of chronic pain prevention (ie, chronic postsurgical pain, postherpetic neuralgia, chronic low back pain, and painful chemotherapy-induced peripheral neuropathy). The issues discussed can, in many instances, be extrapolated to other chronic pain conditions. These examples were selected because they are representative models of primary and secondary prevention, reflect persistent pain resulting from multiple insults (ie, surgery, viral infection, injury, and toxic or noxious element exposure), and are chronically painful conditions that are treated with a range of interventions. Improvements in the design of chronic pain prevention trials could improve assay sensitivity and thus accelerate the identification of efficacious interventions. Such interventions would have the potential to reduce the prevalence of chronic pain in the population. Additionally, standardization of outcomes in prevention clinical trials will facilitate meta-analyses and systematic reviews and improve detection of preventive strategies emerging from clinical trials.

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.

Perioperative nonopioid agents for pain control in spinal surgery

PURPOSE

Commonly used nonopioid analgesic agents that are incorporated into multimodal perioperative pain management protocols in spinal surgery are reviewed.

SUMMARY

Spinal procedures constitute perhaps some of most painful surgical interventions, as they often encompass extensive muscle dissection, tissue retraction, and surgical implants, as well as prolonged operative duration. Perioperative nonopioid analgesics frequently used in multimodal protocols include gabapentin, pregabalin, acetaminophen, dexamethasone, ketamine, and nonsteroidal antiinflammatory drugs (NSAIDs). There is evidence to suggest that gabapentin is safe and effective in reducing opioid consumption and pain scores at optimal doses of 600-900 mg orally administered preoperatively. Pregabalin 150-300 mg orally perioperatively has been shown to reduce both pain and narcotic consumption. Most reports concur that a single 1-g i.v. perioperative dose is safe in adults and that this dose has been shown to reduce pain and attenuate narcotic requirements. Dexamethasone's influence on postoperative pain has primarily been investigated for minor spinal procedures, with limited evidence for spinal fusions. Ketamine added to a patient-controlled analgesia regimen appears to be efficacious for 24 hours postoperatively when implemented for microdiskectomy and laminectomy procedures at doses of 1 mg/mL in a 1:1 mixture with morphine. For patients undergoing laminectomy or diskectomy, NSAIDs appear to be safe and effective in reducing pain scores and decreasing opioid consumption.

CONCLUSION

Preemptive analgesic therapy combining nonopioid agents with opioids may reduce narcotic consumption and improve patient satisfaction after spinal surgery. Such therapy should be considered for patients undergoing various spinal procedures in which postoperative pain control has been historically difficult to achieve.

Preventive analgesia in hip or knee arthroplasty: a systematic review

OBJECTIVE

To analyze the efficacy and safety of preventive analgesia in patients undergoing hip or knee arthroplasty due to osteoarthritis.

METHODS

A systematic literature review was performed, using a defined a sensitive strategy on Medline, Embase and Cochrane Library up to May 2013. The inclusion criteria were: patients undergoing knee and/or hip arthroplasty, adults with moderate or severe pain (≥4 on a Visual Analog Scale). The intervention, the use (efficacy and safety) of pharmacological treatment (preventive) close to surgery was recorded. Oral, topical and skin patch drugs were included. Systematic reviews, meta-analysis, controlled trials and observational studies were selected.

RESULTS

A total of 36 articles, of moderate quality, were selected. The patients included were representative of those undergoing knee and/or hip arthroplasty in Spain. They had a mean age >50 years, higher number of women, and reporting moderate to severe pain (≥4 on a Visual Analog Scale). Possurgical pain was mainly evaluated with a Visual Analog Scale. A wide variation was found as regards the drugs used in the preventive protocols, including acetaminophen, classic NSAID, Cox-2, opioids, corticosteroids, antidepressants, analgesics for neuropathic pain, as well as others, such as magnesium, ketamine, nimodipine or clonidine. In general, all of them decreased post-surgical pain without severe adverse events.

CONCLUSIONS

The use or one or more pre-surgical analgesics decreases the use of post-surgical drugs, at least for short term pain.

Analgesic techniques in hip and knee arthroplasty: from the daily practice to evidence-based medicine

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are major orthopedic surgery models, addressing mainly ageing populations with multiple comorbidities and treatments, ASA II–IV, which may complicate the perioperative period. Therefore effective management of postoperative pain should allow rapid mobilization of the patient with shortening of hospitalization and social reintegration. In our review we propose an evaluation of the main analgesics models used today in the postoperative period. Their comparative analysis shows the benefits and side effects of each of these methods and guides us to how to use evidence-based medicine in our daily practice.

Perioperative gabapentinoids: choice of agent, dose, timing, and effects on chronic postsurgical pain

This article summarizes the current evidence for the use of gabapentinoids in the perioperative setting and provides useful clinical recommendations regarding dosing, timing, and choice of agent.

Local infiltration analgesia followed by continuous infusion of local anesthetic solution for total hip arthroplasty: a prospective, randomized, double-blind, placebo-controlled study

BACKGROUND

We studied the efficacy of local infiltration analgesia in surgical wounds with 0.2% ropivacaine (50 mL), ketorolac (15 mg), and adrenaline (0.5 mg) compared with that of local infiltration analgesia combined with continuous infusion of 0.2% ropivacaine as a method of pain control after total hip arthroplasty. We hypothesized that as a component of multimodal analgesia, local infiltration analgesia followed by continuous infusion of ropivacaine would result in reduced postoperative opioid consumption and lower pain scores compared with infiltration alone, and that both of these techniques would be superior to placebo.

METHODS

In this prospective, double-blind, placebo-controlled study, 105 patients were randomized into three groups: Group I, in which patients received infiltration with ropivacaine, ketorolac, and adrenaline followed by continuous infusion of 0.2% ropivacaine at 5 mL/hr; Group II, in which patients received infiltration with ropivacaine, ketorolac, and adrenaline followed by continuous infusion of saline solution at 5 mL/hr; and Group III, in which patients received infiltration with saline solution followed by continuous infusion of saline solution at 5 mL/hr.All patients received celecoxib, pregabalin, and acetaminophen perioperatively and patient-controlled analgesia; surgery was performed under general anesthesia. Before wound closure, the tissues and periarticular space were infiltrated with ropivacaine, ketorolac, and adrenaline or saline solution and a fenestrated catheter was placed. The catheter was attached to a pump prefilled with either 0.2% ropivacaine or saline solution set to infuse at 5 mL/hr.The primary outcome measure was postoperative opioid consumption and the secondary outcome measures were pain scores, adverse side effects, and patient satisfaction.

RESULTS

There were no differences between groups in the administration of opioids in the operating room, in the recovery room, or on the surgical floor. The pain scores on recovery room admission and discharge and the floor were low and similar between groups. There were no differences in the incidence of adverse side effects among groups. Patient satisfaction with pain management was similar in all groups.

CONCLUSIONS

Local infiltration analgesia alone or followed by continuous infusion of ropivacaine as part of multimodal analgesia provides no additional analgesic benefit or reduction in opioid consumption compared with placebo following total hip arthroplasty.

LEVEL OF EVIDENCE

Therapeutic level I. See Instructions for Authors for a complete description of levels of evidence.

Persistent pain after total knee or hip arthroplasty: differential study of prevalence, nature, and impact

This study compares the incidence, nature, and impact of persistent post-surgical pain after total knee arthroplasty (TKA) and total hip arthroplasty (THA) and investigates differences between these procedures, with the focus on potential presurgical and post-surgical issues that could be related to the distinct persistent post-surgical pain outcomes between these two groups. A consecutive sample of 92 patients was assessed prospectively 24 hours before, 48 hours, and 4-6 months after surgery. The data show that TKA patients had a higher likelihood of developing persistent post-surgical pain, of reporting higher pain levels, and of using more neuropathic descriptors when classifying their pain. In addition, TKA patients more often reported interference from pain on functional domains, including general activity, walking ability, and normal work. Demographic factors, like gender and age, along with presurgical clinical factors like disease onset, existence of medical comorbidities, and other pain problems, may have contributed to these differences, whereas baseline psychologic factors and functionality levels did not seem to exert an influence. Heightened acute post-surgical pain experience among TKA patients could also be related to distinct outcomes for persistent post-surgical pain. Future prospective studies should therefore collect TKA and THA samples wherein patients are homogeneous for demographic and presurgical clinical issues. Overall, these findings contribute to a small but growing body of literature documenting persistent post-surgical pain after major arthroplasty, conducted in different countries and across different health care settings.