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

Opioid-induced hyperalgesia in clinical anesthesia practice: what has remained from theoretical concepts and experimental studies?

PURPOSE OF REVIEW

This article reviews the phenomenon of opioid-induced hyperalgesia (OIH) and its implications for clinical anesthesia. The goal of this review is to give an update on perioperative prevention and treatment strategies, based on findings in preclinical and clinical research.

RECENT FINDINGS

Several systems have been suggested to be involved in the pathophysiology of OIH with a focus on the glutaminergic system. Very recently preclinical data revealed that peripheral μ-opioid receptors (MORs) are key players in the development of OIH and acute opioid tolerance (AOT). Peripheral MOR antagonists could, thus, become a new prevention/treatment option of OIH in the perioperative setting. Although the impact of OIH on postoperative pain seems to be moderate, recent evidence suggests that increased hyperalgesia following opioid treatment correlates with the risk of developing persistent pain after surgery. In clinical practice, distinction among OIH, AOT and acute opioid withdrawal remains difficult, especially because a specific quantitative sensory test to diagnose OIH has not been validated yet.

SUMMARY

Since the immediate postoperative period is not ideal to initiate long-term treatment for OIH, the best strategy is to prevent its occurrence. A multimodal approach, including choice of opioid, dose limitations and addition of nonopioid analgesics, is recommended.

Botulinum toxin type A and gabapentin attenuate postoperative pain and NK1 receptor internalization in rats

Treatment of postoperative pain remains a challenge in clinic. Botulinum toxin type A (BoNT/A) and gabapentin regulate the release of neurotransmitters from primary afferent neurons, but their effects of on postoperative pain are not clear. In the current study, using pain behavioral tests, Western blot analysis, and immunocytochemistry, we examined whether BoNT/A, alone or in combination with intrathecal gabapentin, inhibited pain hypersensitivity and attenuated the increase in neurokinin 1 (NK1) receptor internalization in dorsal horn neurons after plantar incision. Our data showed that pretreatment of rats with an intraplantar (2 U) 24 h before plantar incision or intrathecal (0.5 U) injection of BoNT/A 48 h before plantar incision induced a prolonged (3-5 days) decrease in pain scores and mechanical hypersensitivity, as compared to those observed with saline pretreatment. Both intraplantar and intrathecal BoNT/A pretreatment reduced synaptosomal-associated protein 25 levels in the ipsilateral lumbar dorsal root ganglia and spinal cord dorsal horn, and attenuated the increase in NK1 receptor internalization in dorsal horn neurons. Intrathecal administration of a sub-effective dose of gabapentin (50 μg) with BoNT/A (0.5 U) induced greater inhibition of pain hypersensitivity and NK1 receptor internalization than BoNT/A alone. These findings suggest that pretreatment with BoNT/A, alone or in combination with intrathecal gabapentin, may present a promising multimodal analgesia regimen for postoperative pain treatment.

Opioid misuse in gastroenterology and non-opioid management of abdominal pain

Opioids were one of the earliest classes of medications used for pain across a variety of conditions, but morbidity and mortality have been increasingly associated with their chronic use. Despite these negative consequences, chronic opioid use is increasing worldwide, with the USA and Canada having the highest rates. Chronic opioid use for noncancer pain can have particularly negative effects in the gastrointestinal and central nervous systems, including opioid-induced constipation, narcotic bowel syndrome, worsening psychopathology and addiction. This Review summarizes the evidence of opioid misuse in gastroenterology, including the lack of evidence of a benefit from these drugs, as well as the risk of harm and negative consequences of opioid use relative to the brain-gut axis. Guidelines for opioid management and alternative pharmacological and nonpharmacological strategies for pain management in patients with gastrointestinal disorders are also discussed. As chronic pain is complex and involves emotional and social factors, a multimodal approach targeting both pain intensity and quality of life is best.

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

Background and Aims:

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

Methods:

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

Results:

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

Conclusion:

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

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.

Prevalence and Predictors of Persistent Post-Surgical Opioid Use: A Prospective Observational Cohort Study

Post-surgical opioid prescribing intended for the short-term management of acute pain may lead to long-term opioid use. This study was undertaken to determine the prevalence of persistent post-surgical opioid use and patient-related factors associated with post-surgical opioid use. One thousand and thirteen opioid-naïve patients awaiting elective surgery in a tertiary private hospital in Sydney were enrolled. Preoperatively, patients completed a questionnaire comprising potential predictors of persistent post-surgical opioid use. Patients underwent surgery with routine perioperative care, and were followed up at 90 to 120 days after surgery to determine opioid use. Factors associated with opioid use were assessed with logistic regression. We had an overall response rate of 95.8% (n=970) of patients, of whom 10.5% (n=102) continued to use opioids at >90 days after surgery. On surgical subtype analysis, the prevalence of persistent opioid use was 23.6% after spinal surgery, and 13.7% after orthopaedic surgery. Four factors were independently associated with persistent post-surgical opioid use in a multivariate model: having orthopaedic (odds ratio [OR] 4.6, 95% confidence interval [CI] 2.0 to 10.8, P <0.001) or spinal surgery (OR 4.0, 95% CI 1.7 to 9.2, P <0.001), anxiety (OR 2.1, 95% CI 1.1 to 4.1, P=0.03), attending pre-admission clinic (OR 3.7, 95% CI 1.6 to 8.6, P=0.002), and higher self-reported pain score at >90 days after surgery (P <0.001). More than 10% of opioid-naïve patients undergoing elective surgery experience persistent post-surgical opioid use. Identification of factors associated with persistent post-surgical opioid use may allow development of a risk stratification tool to predict those at highest risk.

Chronic Opioid Use After Surgery: Implications for Perioperative Management in the Face of the Opioid Epidemic

Physicians, policymakers, and researchers are increasingly focused on finding ways to decrease opioid use and overdose in the United States both of which have sharply increased over the past decade. While many efforts are focused on the management of chronic pain, the use of opioids in surgical patients presents a particularly challenging problem requiring clinicians to balance 2 competing interests: managing acute pain in the immediate postoperative period and minimizing the risks of persistent opioid use after the surgery. Finding ways to minimize this risk is particularly salient in light of a growing literature suggesting that postsurgical patients are at increased risk for chronic opioid use. The perioperative care team, including surgeons and anesthesiologists, is poised to develop clinical- and systems-based interventions aimed at providing pain relief in the immediate postoperative period while also reducing the risks of opioid use longer term. In this paper, we discuss the consequences of chronic opioid use after surgery and present an analysis of the extent to which surgery has been associated with chronic opioid use. We follow with a discussion of the risk factors that are associated with chronic opioid use after surgery and proceed with an analysis of the extent to which opioid-sparing perioperative interventions (eg, nerve blockade) have been shown to reduce the risk of chronic opioid use after surgery. We then conclude with a discussion of future research directions.

Perioperative Gabapentin Does Not Reduce Postoperative Delirium in Older Surgical Patients: A Randomized Clinical Trial

BACKGROUND

Postoperative pain and opioid use are associated with postoperative delirium. We designed a single-center, randomized, placebo-controlled, parallel-arm, double-blinded trial to determine whether perioperative administration of gabapentin reduced postoperative delirium after noncardiac surgery.

METHODS

Patients were randomly assigned to receive placebo (N = 347) or gabapentin 900 mg (N = 350) administered preoperatively and for the first 3 postoperative days. The primary outcome was postoperative delirium as measured by the Confusion Assessment Method. Secondary outcomes were postoperative pain, opioid use, and length of hospital stay.

RESULTS

Data for 697 patients were included, with a mean ± SD age of 72 ± 6 yr. The overall incidence of postoperative delirium in any of the first 3 days was 22.4% (24.0% in the gabapentin and 20.8% in the placebo groups; the difference was 3.20%; 95% CI, 3.22% to 9.72%; P = 0.30). The incidence of delirium did not differ between the two groups when stratified by surgery type, anesthesia type, or preoperative risk status. Gabapentin was shown to be opioid sparing, with lower doses for the intervention group versus the control group. For example, the morphine equivalents for the gabapentin-treated group, median 6.7 mg (25th, 75th quartiles: 1.3, 20.0 mg), versus control group, median 6.7 mg (25th, 75th quartiles: 2.7, 24.8 mg), differed on the first postoperative day (P = 0.04).

CONCLUSIONS

Although postoperative opioid use was reduced, perioperative administration of gabapentin did not result in a reduction of postoperative delirium or hospital length of stay.

The efficacy of gabapentin in reducing pain intensity and postoperative nausea and vomiting following laparoscopic cholecystectomy: A meta-analysis

BACKGROUND

It is unknown whether gabapentin is effective in reducing acute pain following laparoscopic cholecystectomy. The purpose of the current meta-analysis was to evaluate the efficacy of gabapentin in reducing pain intensity and postoperative nausea and vomiting (PONV) after laparoscopic cholecystectomy.

METHODS

All randomized controlled trials (RCTs) evaluating the efficacy of gabapentin in reducing pain intensity and PONV after laparoscopic cholecystectomy were searched on the following databases: PubMed, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), the Google database, the Chinese Wanfang database, and the China National Knowledge Infrastructure (CNKI). The most recent literature search was conducted on March 21, 2017. Outcomes including visual analog scale (VAS) at 12 and 24 hours, total morphine consumption, and the occurrence of PONV. Continuous outcomes were expressed as the weighted mean difference (WMD) and 95% confidence interval (CI), and the one discontinuous outcome was expressed as risk ratio (RR) and 95% CI. Stata 12.0 software was used for meta-analysis.

RESULTS

A total of 9 studies involving 966 patients were identified. In total, there were 484 gabapentin subjects and 482 controls. Compared with the control group, gabapentin was associated with lower VAS at 12 hours (WMD = -10.18, 95% CI: -17.36 to -2.80, P = .007) and 24 hours (WMD = -6.33, 95% CI: -8.41 to -4.25, P = .000), which was equivalent on a 110-point VAS scale to 10.18 points at 12 hours and 6.33 points at 24 hours. Compared with the control group, gabapentin was associated with less total morphine consumption by approximately 110.83 mg (WMD = -110.83, 95% CI: -183.25 to -38.42, P = .003). In addition, the occurrence of nausea and vomiting in gabapentin was decreased (25.2% vs 47.6, RR = 0.53, 95% CI: 0.44-0.63, P = .000).

CONCLUSION

Gabapentin was efficacious in reducing postoperative pain, total morphine consumption, and morphine-related complications following laparoscopic cholecystectomy. In addition, there was a negative correlation between the gabapentin dosage and the occurrence of nausea and vomiting. The number of included studies is limited, and more studies are needed to verify the effects of gabapentin in laparoscopic cholecystectomy patients.

Total pancreatectomy for recurrent acute and chronic pancreatitis: a critical review of patient selection criteria

PURPOSE OF REVIEW

Critical review of the indications for total pancreatectomy and highlight limitations in current diagnostic criteria for chronic pancreatitis.

RECENT FINDINGS

The diagnosis of noncalcific chronic pancreatitis remains controversial because of an overreliance on nonspecific imaging and laboratories findings. Endoscopic ultrasound, s-magnetic resonance cholangiopancreatography, and/or endoscopic pancreatic function testing are often used to diagnose noncalcific chronic pancreatitis despite the fact that there is no gold standard for this condition. Abdominal pain is not specific for chronic pancreatitis and is more likely to be encountered in patients with functional gastrointestinal disorders based on the high incidence of these conditions. The duration of pain and opioid analgesic use results in central sensitization that adversely affects pain outcomes after total pancreatectomy. An alcoholic cause is associated with poorer pain outcomes after total pancreatectomy.

SUMMARY

The lack of a gold standard for noncalcific chronic pancreatitis limits the diagnostic accuracy of imaging and laboratory tests. The pain of chronic pancreatitis is nonspecific and is affected by duration, preoperative opioid use, and cause. These factors will need to be considered in the development of future selection criteria for this morbid surgery.

Preemptive analgesia by using celecoxib combined with tramadol/APAP alleviates post-operative pain of patients undergoing total knee arthroplasty

OBJECTIVE

This study was aimed to evaluate the efficacy of preemptive analgesia (PA) by using celecoxib combined with low-dose tramadol/acetaminophen (tramadol/APAP) in treating post-operative pain of patients undergoing unilateral total knee arthroplasty (TKA).

METHODS

A total of 132 patients scheduled for TKA were included in this study. Three-day pre-operative medication was administrated in PA group with subsequent effective intra- and post-operative multimodal analgesia, while control patients received multimodal analgesia without PA. Visual analog scale (VAS) was utilized to assess the pain intensity at rest and during movement. VAS scores of participants were recorded 3 days before surgery, 1 day, 3 days, 1 week, 3 weeks, 6 weeks, 3 months, 6 months, and 12 months postoperatively. Moreover, the length of hospital stay, expense of hospitalization, C-reactive protein (CRP) values during hospitalization, and complications during medication were also recorded.

RESULTS

PA showed superiority over control at 3 weeks (P = 0.013) and 6 weeks (P = 0.046) in resting pain, and 1 week (P = 0.015), 3 weeks (P = 0.003), 6 weeks (P = 0.003) and 3 months (P = 0.012) postoperatively in movement pain. There was no statistically significant difference in the length of hospital stay, total expense, CRP values, as well as complications.

CONCLUSIONS

Based on satisfactory intra- and post-operative analgesia, PA by 3-day administration of celecoxib and low-dose tramadol/APAP might be an effective and safe therapy regarding patients undergoing TKA in terms of alleviating post-operative pain.

A meta-analysis of the preoperative use of gabapentinoids for the treatment of acute postoperative pain following spinal surgery

BACKGROUND

Gabapentinoid drugs, which include gabapentin and pregabalin, play an established role in the management of neuropathic pain. However, whether preoperative administration of gabapentinoids has a beneficial role in controlling acute pain after spinal surgery is unknown. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to determine the efficacy and safety of the preoperative use of gabapentinoids (gabapentin and pregabalin) for the treatment of acute postoperative pain following spinal surgery.

METHODS

In March 2017, a systematic computer-based search was conducted in PubMed, EMBASE, Web of Science, Cochrane Library, and Google databases. RCTs comparing gabapentinoids (gabapentin and pregabalin) with placebo in patients undergoing spine surgery were retrieved. The primary endpoint was the visual analogue scale (VAS) score with rest or mobilization at 6, 12, 24, and 48 hours and cumulative morphine consumption at 24 and 48 hours. The secondary outcomes were complications of nausea, vomiting, sedation, dizziness, headache, urine retention, pruritus, and visual disturbances. After tests for publication bias and heterogeneity among studies were performed, data were aggregated for random-effects models when necessary.

RESULTS

Sixteen clinical studies (gabapentin group n = 8 and pregabalin group n = 8) were ultimately included in the meta-analysis. Gabapentinoids were associated with reduced pain scores at 6, 12, 24, and 48 hours. Similarly, gabapentinoids were associated with a reduction in cumulative morphine consumption at 24 and 48 hours. Furthermore, gabapentinoids can significantly reduce the occurrence of nausea, vomiting, and pruritus. There were no significant differences in the occurrence of sedation, dizziness, headache, visual disturbances, somnolence, or urine retention.

CONCLUSIONS

Preoperative use of gabapentinoids was able to reduce postoperative pain, total morphine consumption, and morphine-related complications following spine surgery. Further studies should determine the optimal dose and whether pregabalin is superior to gabapentin in controlling acute pain after spine surgery.

A Comparison of Multimodal Analgesic Approaches in Institutional Enhanced Recovery After Surgery Protocols for Colorectal Surgery: Pharmacological Agents

INTRODUCTION

Enhanced Recovery After Surgery (ERAS^®) protocols are the cornerstone of improved recovery after colorectal surgery. Their implementation leads to reduced morbidity and shorter hospital stays while attenuating the surgical stress response. Multimodal analgesia is an important part of ERAS protocols. We compared and contrasted protocols from 15 institutions to test our hypothesis that there is a fundamental consensus among them.

MATERIALS AND METHODS

ERAS protocols for open and laparoscopic colorectal surgery were compared from 15 different healthcare facilities. We examined each institution's approach to multimodal analgesia related to the use of oral and intravenous analgesics. Preoperative, intraoperative, and postoperative management was examined.

RESULTS

All but three protocols used preoperative multimodal analgesics, with acetaminophen, celecoxib, and gabapentin being the most common. Intraoperative recommendations included the use of ketamine, lidocaine, magnesium, and ketorolac. Some protocols advocated for the use of opiates, while others aimed to minimize total opioid dose. In the postoperative period, the three most utilized agents were acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), and opioids.

CONCLUSIONS

There were many similarities and some significant differences among ERAS protocols examined. Acetaminophen was the most widely used nonopioid agent and along with NSAIDs offers a benefit with respect to postoperative analgesia, opioid-sparing effects, earlier ambulation, and reduction in postoperative ileus. Gabapentin was widely used as it may reduce opioid consumption within the first 24 hours postoperatively. Lidocaine infusion was recommended if there were contraindications to or failure of epidural anesthesia. Ketamine is frequently recommended due to its analgesic, antihyperalgesic, antiallodynic, and antitolerance properties. Differences in approaches may be due to both institutional- and provider-level factors.

Gabapentin can decrease acute pain and morphine consumption in spinal surgery patients: A meta-analysis of randomized controlled trials

BACKGROUND

Approximately 80% of patients who underwent spinal surgeries experience moderate to extreme postoperative pain. Gabapentin was used as an adjunct for the management of acute pain in approximately half of enhanced recovery programs. This meta-analysis aimed to illustrate the efficacy and safety of gabapentin for pain management following spinal surgery.

METHODS

In January 2017, a systematic computer-based search was conducted in PubMed, EMBASE, Web of Science, Cochrane Database of Systematic Reviews, and Google database. Data on patients prepared for spine surgery in studies that compared gabapentin versus placebo were retrieved. The primary endpoint was the visual analog scale (VAS) at 12 hours and 24 hours and total morphine consumption. The secondary outcomes were complications that included nausea, dizziness, somnolence, headache, pruritus, urine retention, and vomiting. After testing for publication bias and heterogeneity between studies, data were aggregated for random-effects models when necessary.

RESULTS

Seven clinical studies with 581 patients (gabapentin group=383, control group=198) were ultimately included in the meta-analysis. Gabapentin was associated with reduced pain scores at 12 hours and 24 hours, corresponding to a reduction of 11.18 points (95% CI, -13.85 to -8.52 points) at 12 hours and 9.94 points (95% CI, -13.99 to -5.89 points) at 24 hours on a 100-point VAS. Similarly, gabapentin was associated with a reduction in total morphine consumption (-2.04, 95% CI -2.71, -1.37). Furthermore, gabapentin can reduce the occurrence of vomiting (risk ratio [RR] 0.46, 95% CI 0.27, 0.78, P = 0.004), urine retention (RR = 0.57, 95% CI 0.34, 0.98, P = 0.041, NNT = 11.9) and pruritus (RR = 0.38, 95% CI 0.22, 0.66, P = 0.001, NNT = 5.6) and the number needed to treat (NNT = 20.1). There were no significant differences in the occurrence of nausea, dizziness, somnolence, or headache.

CONCLUSIONS

Gabapentin was efficacious in the reduction of postoperative pain, total morphine consumption, and morphine-related complications following spine surgery. In addition, a high dose (≥900 mg/d) of gabapentin is more effective than a low dose (<900 mg/d). The number of included studies is limited, and more studies are needed to verify the effects of gabapentin in spinal surgery patients.

Comprehensive approach to the management of the patient with multiple rib fractures: a review and introduction of a bundled rib fracture management protocol

Rib fractures are common among patients sustaining blunt trauma, and are markers of severe bodily and solid organ injury. They are associated with high morbidity and mortality, including multiple pulmonary complications, and can lead to chronic pain and disability. Clinical and radiographic scoring systems have been developed at several institutions to predict risk of complications. Clinical strategies to reduce morbidity have been studied, including multimodal pain management, catheter-based analgesia, pulmonary hygiene, and operative stabilization. In this article, we review risk factors for morbidity and complications, intervention strategies, and discuss experience with bundled clinical pathways for rib fractures. In addition, we introduce the multidisciplinary rib fracture management protocol used at our level I trauma center.

Evaluating the Implementation of a Preemptive, Multimodal Analgesia Protocol in a Plastic Surgery Office

Many patients undergoing plastic surgery experience significant pain postoperatively. The use of preemptive, multimodal analgesia techniques to reduce postoperative pain has been widely described in the literature. This quality improvement project evaluated the implementation of a preemptive, multimodal analgesia protocol in an office-based plastic surgery facility to decrease postoperative pain, decrease postoperative opioid consumption, decrease postanesthesia care time, and increase patient satisfaction. The project included adult patients undergoing surgical procedures at an outpatient plastic and cosmetic surgery office, and the protocol consisted of oral acetaminophen 1,000 mg and gabapentin 1,200 mg. Using a pre-/postintervention design, data were collected from patient medical records and telephone interviews of patients receiving the standard preoperative analgesia regimen (preintervention group: n = 24) and the evidence-based preemptive, multimodal analgesia protocol (postintervention group: n = 23). Results indicated no significant differences between the pre- and postintervention groups for any of the outcomes measured. However, results showed that patients in both groups experienced moderate to severe pain postoperatively. In addition, adverse side effects such as dizziness and drowsiness were higher in the postintervention group than in the preintervention group. Although this quality improvement project did not meet the goals it set out to achieve for patients undergoing plastic surgery, it did illustrate the substantial presence of pain after surgical procedures. Thus, clinicians need to continue to focus on identifying targeted treatment plans that use multimodal, non-opioid-based strategies to manage and prevent postoperative pain.