Pregabalin Has Analgesic, Ventilatory, and Cognitive Effects in Combination with Remifentanil

The calcium channel agonist (±)-BAY-K-8644 attenuates the ability of gabapentinoids to increase the potency of fentanyl and heroin and decrease the potency of cocaine and d-methamphetamine to elicit discriminative stimulus effects in rats

During the opioid epidemic there has been a significant increase in the number of prescriptions for gabapentinoids (gabapentin and pregabalin), which block the α2δ-subunit of voltage-gated calcium channels (VGCCs). In rats, gabapentinoids enhance the potency of the mu opioid receptor (MOR) agonists fentanyl and heroin and decrease the potency of the stimulant drugs cocaine and d-methamphetamine to elicit discriminative stimulus effects. Moreover, (±)-BAY-K-8644, a dihydropyridine-type agonist at the α1-subunit of VGCCs (α1-VGCCs), prevents the antiallodynic effects of gabapentin in rats. The mechanism(s) of interaction between gabapentinoids and MOR agonists and between gabapentinoids and stimulant drugs is/are unclear. This study tested the following hypotheses: (1) the dihydropyridine-type α1-VGCC blocker nimodipine increases the potency of MOR agonists to elicit discriminative stimulus effects; and (2) (±)-BAY-K-8644 attenuates the ability of gabapentinoids and nimodipine to increase the potency of MOR agonists to elicit discriminative stimulus effects. In rats trained to discriminate fentanyl (0.0032 mg/kg) or cocaine (3.2 mg/kg) from saline, neither (±)-BAY-K-8644 nor nimodipine elicited significant fentanyl- or cocaine-appropriate responding. (±)-BAY-K-8644 did not significantly alter discrimination dose-effect functions of MOR agonists or stimulant drugs whereas nimodipine dose-dependently shifted the MOR agonist discrimination dose-effect functions to the left and the stimulant drug discrimination dose-effect functions to the right. (±)-BAY-K-8644 dose-dependently attenuated the ability of nimodipine and gabapentinoids to increase the potency of MOR agonists and decrease the potency of stimulant drugs to elicit discriminative stimulus effects. These results suggest that gabapentinoids alter the potency of MOR agonists and stimulant drugs to elicit discriminative stimulus effects via blockade of α1-VGCCs. SIGNIFICANCE STATEMENT: Prescriptions for gabapentinoids (gabapentin and pregabalin) increased significantly during the opioid epidemic. Using (±)-BAY-K-8644, a dihydropyridine-type agonist at the α1-subunit of the voltage-gated calcium channel (α1-VGCC), this study reports that in male and female rats, gabapentinoids increase the potency of fentanyl and heroin and decrease the potency of cocaine and d-methamphetamine to elicit discriminative stimulus effects via blockade of dihydropyridine-binding sites on α1-VGCC. These results suggest that actions of drugs at α1-VGCCs contribute to the opioid epidemic and opioid/stimulant co-use.

Gabapentinoids Increase the Potency of Fentanyl and Heroin and Decrease the Potency of Naloxone to Antagonize Fentanyl and Heroin in Rats Discriminating Fentanyl

Despite a significant decrease in the number of prescriptions for opioids, the opioid crisis continues, fueled in large part by the availability of the phenylpiperidine mu opioid receptor (MOR) agonist fentanyl. In contrast, the number of prescriptions for and the off-label use of gabapentinoids (gabapentin and pregabalin) has increased dramatically, with gabapentinoids commonly detected in opioid overdose victims. Although gabapentinoids can decrease the potency of the opioid receptor antagonist naloxone to reverse heroin-induced hypoventilation in male rats, the specificity and nature of interaction between gabapentinoids and MOR agonists and any potential sex difference in those interactions are not well characterized. Gabapentinoids were studied in female and male rats discriminating fentanyl (0.0032 mg/kg, i.p.) or cocaine (3.2 mg/kg, i.p.). Alone, neither gabapentin nor pregabalin significantly increased fentanyl- or cocaine-appropriate responding. In rats discriminating fentanyl, each gabapentinoid dose-dependently shifted the fentanyl and heroin discrimination dose-effect functions to the left, whereas naloxone dose-dependently shifted the fentanyl and heroin discrimination dose-effect functions to the right. Each gabapentinoid (100 mg/kg) significantly decreased the potency of naloxone to antagonize the discriminative stimulus effect of fentanyl or heroin. In contrast, each gabapentinoid dose-dependently shifted the cocaine and d-methamphetamine discrimination dose-effect functions to the right. There were no significant sex differences in this study. These results suggest that gabapentinoids impact the misuse of opioids, the co-use of opioids and stimulant drugs, and the increasing number of overdose deaths in individuals using opioids, stimulant drugs, and gabapentinoids in mixtures. SIGNIFICANCE STATEMENT: The number of prescriptions for and the off-label use of gabapentinoids (gabapentin and pregabalin) has increased dramatically, with gabapentinoids commonly detected in opioid overdose victims. This study reports that in rats gabapentinoids increase the potency of fentanyl and heroin to produce discriminative stimulus effects while decreasing the potency of naloxone to antagonize those effects of fentanyl and heroin. These results can help guide policies for regulating gabapentinoids and treating opioid misuse and overdose.

The effect of pre-emptive oral pregabalin on opioid consumption in patients undergoing laparoscopic sleeve gastrectomy with an analysis of intraoperative hemodynamic stability and quality of recovery: study protocol for a randomized, prospective, double-blind study

BACKGROUND

Obese patients undergoing laparoscopic sleeve gastrectomy (LSG) are particularly at risk of opioid-related side effects. To reduce patient exposure to opioids, multimodal analgesia, which involves the use of drugs of different classes, may be utilized. One of the drugs under consideration is pregabalin. Despite an opioid-sparing potential, few studies assess the role of pregabalin as an element of multimodal analgesia in LSG. Considering the limited number and inconsistent results of available studies, we decided to conduct a randomized, prospective study on the effect of preemptive pregabalin administration in obese patients on opioid consumption, pain scores, the incidence of opioid side effects, and hemodynamical stability.

METHODS

The study is designed as a prospective randomized controlled trial with double-blinding. Randomization will be performed in a block with a parallel 1:1 allocation. The intervention will involve receiving a pregabalin 150 mg capsule 1-2 h before the surgery, whereas the control group will receive an identically looking placebo. The primary outcome measure will be total oxycodone consumption in the first 24 h following surgery. Secondary outcome measures will be pain severity assessed using the Numerical Rating Scale (NRS) 1, 6, 12, and 24 h after surgery, postoperative sedation on the Ramsay scale, PONV impact scale, the incidence of desaturation episodes < 94%, and episodes of blurred vision at 1, 6, 12, and 24 h after surgery, intraoperative hemodynamic parameters such as heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean blood pressure (MBP), total fluid volume, and total ephedrine dose. Patient comfort will be additionally assessed using the QoR-40 questionnaire at discharge.

DISCUSSION

The study will explore the efficacy and safety of preemptive pregabalin in a dose of 150 mg as a co-analgesic used in multimodal analgesia for LSG. As studies on opioid-sparing regimes concern the safety of obese patients, we aim to contribute objective data with a relatively large study sample size. The result of the present clinical trial may support the reassessment of recommendations to use pregabalin in the studied population.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05804591. Registered on 07.04.2023.

Gabapentin May Not Decrease Opioid Use in Pediatric Enhanced Recovery After Surgery Protocols

INTRODUCTION

In adults, the use of gabapentin in Enhanced Recovery After Surgery (ERAS) protocols is associated with increased morbidity and clinically insignificant improvement in postoperative pain control. Furthermore, there are limited data supporting its use in pediatric ERAS protocols.

METHODS

A single-institution retrospective study was performed to examine the correlation of gabapentin use and postoperative outcomes among children who underwent elective general, urologic, and orthopedic surgeries. Because gabapentin was removed from our institutional ERAS protocols in August 2020, we compared eligible patients from January 2018 to September 2021 using univariate and multivariable analysis. Due to heterogeneity between the treatment groups, a propensity score-matched analysis was also performed. Significance was defined as P < 0.05.

RESULTS

In this study, 196 patients were included, with 91 (46.4%) who received gabapentin and 105 (53.6%) who did not. When used in combination with opioids, gabapentin was not associated with a reduction in the amount of opioids consumed (β = -0.4, 95% confidence interval = -1.9, 1.1). Instead, children who received gabapentin had increased odds of requiring oxygen supplementation (odds ratio = 3.1, 95% confidence interval = 1.2, 9.0), but this finding did not persist after propensity score-matched analysis.

CONCLUSIONS

The use of gabapentin in multimodal pain regimens in children following elective surgery was not associated with a decrease in postoperative narcotic use. Inclusion of gabapentin in perioperative pain medication protocols should be further evaluated with prospective studies.

The effect of pregabalin on postoperative pain after anterior cruciate ligament reconstruction: A systematic review of randomized clinical trials

Background

Despite the enormous success of anterior cruciate ligament (ACL) reconstruction, acute neuropathic pain can develop postoperatively and is both distressing and difficult to treat once established. Pregabalin, an anticonvulsant agent that selectively affects the nociceptive process, has been used as a pain relief agent. The purpose of this systematic review of randomized controlled trials (RCTs) was to evaluate the pain control effect of pregabalin versus placebo after ACL reconstruction.

Method

A search of the literature was performed from inception to June 2022, using PubMed, Scopus, Google Scholar, Web of Science, Cochrane and EBSCO. Studies considered for inclusion were RCTs that reported relevant outcomes (postoperative pain scores, cumulative opioid consumption, adverse events) following administration of pregabalin in patients undergoing ACL reconstruction.

Result

Five placebo-controlled RCTs involving 272 participants met the inclusion criteria. 75 mg and 150 mg oral pregabalin was used in included trials. Two studies used a single dose of pregabalin one hour before anesthesia induction. Two studies used pregabalin 1 hour before anesthesia induction and 12 hours after. One study used daily pregabalin 7 days before and 7 days after surgery. Out of five papers, three papers found significantly lower pain intensity and cumulative opioid consumption in pregabalin group compared with placebo group. However, a decrease in pain scores was found in all trials. Pregabalin administration was associated with dizziness and nausea.

Conclusion

The use of pregabalin may be a valuable asset in pain management after ACL reconstruction. However, future studies with larger sample size and longer follow-up period are required.

Effects of Gabapentinoids on Heroin-Induced Ventilatory Depression and Reversal by Naloxone

Despite an increasing prevalence of gabapentinoids (gabapentin and pregabalin) in opioid overdose deaths, little research has evaluated potentially harmful interactions between gabapentinoids and opioids. This study sought to determine the effects of gabapentinoids on the ventilatory depressive effects of heroin and their reversal by naloxone. Rats were given gabapentin, pregabalin, or saline prior to receiving increasing doses of heroin while ventilation was monitored using whole-body plethysmography. In some sessions naloxone was administered following the largest dose of heroin. The primary outcomes of this study were minute volume and Pause. Heroin dose-dependently reduced minute volume and increased Pause. Administration of naloxone dose-dependently reversed the effects of heroin on ventilation. Gabapentinoids did not alter the ventilatory depressive effects of heroin alone but reduced the potency of naloxone to reverse heroin-induced ventilatory depression. These preliminary findings emphasize the need for further research evaluating interactions between gabapentinoids and opioids related to substance misuse and overdose.

Trends and correlates of concurrent opioid and benzodiazepine and/or gabapentinoid use among Ontario nursing home residents

BACKGROUND

A concern with long-term opioid use is the increased risk arising when opioids are used concurrently with drugs that can potentiate their associated adverse effects. The drugs most often encountered are benzodiazepines (BZDs) and gabapentinoids. Our study objectives were to examine trends in the concurrent use of opioids and BZDs, or gabapentinoids, in a Canadian nursing home population over an 11-year period, and current resident-level correlates of this concurrent use.

METHODS

We conducted a population-based, repeated cross-sectional study among Ontario nursing home residents (>65 years) dispensed opioids between April 2009 and February 2020. For the last study year, we examined cross-sectional associations between resident characteristics and concurrent use of opioids with BZDs or gabapentinoids. Linked data on nursing home residents from clinical and health administrative databases was used. The yearly proportions of residents who were dispensed an opioid concurrently with a BZD or gabapentinoid were plotted with percent change derived from log-binomial regression models. Separate modified Poisson regression models estimated resident-level correlates of concurrent use of opioids with BZDs or gabapentinoids.

RESULTS

Over the study period, among residents dispensed an opioid there was a 53.2% relative decrease (30.7% to 14.4%) in concurrent BZD and a 505.4% relative increase (4.4% to 26.6%) in concurrent gabapentinoid use. In adjusted models, increasing age and worsening cognition were inversely associated with the concurrent use of both classes, but most other significantly related covariates were unique to each drug class (e.g., sex and anxiety disorders for BZD, pain severity and presence of pain-related conditions for gabapentinoids).

CONCLUSIONS

Co-administration of BZDs or gabapentinoids in Ontario nursing home residents dispensed opioids remains common, but the pattern of co-use has changed over time. Observed covariates of concurrent use in 2019/20 suggest distinct but overlapping resident populations requiring consideration of the relative risks versus benefits of this co-use and monitoring for potential harm.

Scheduled, Simultaneous Dosing of Pregabalin, Celecoxib, and Acetaminophen Markedly Reduces or Eliminates Opioid Use After ACL Reconstruction Using Allograft or Hamstring Tendon Autograft: A Randomized Clinical Trial

BACKGROUND

Opioid analgesics continue to be prescribed after ambulatory surgery despite untoward adverse effects, risk of overdose, and association with substance use disorder.

PURPOSE/HYPOTHESIS

The purpose was to investigate the use of a novel system to provide scheduled and simultaneous dosing of acetaminophen, celecoxib, and pregabalin after anterior cruciate ligament reconstruction (ACLR). It was hypothesized that this system would markedly reduce pain and opioid use compared with existing best practice.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Included were 100 patients scheduled for elective, primary ACLR using allograft or hamstring tendon autograft. Selection criteria included age between 18 and 65 years and weight between 65 and 120 kg. Exclusion criteria were a known allergy to any drug used in the study or the use of opioid analgesics before surgery. Patients in the intervention group received a blister pack with scheduled, simultaneous doses of acetaminophen, celecoxib, and pregabalin; patients were also given oxycodone 5 mg as needed for breakthrough pain. Patients in the control group were prescribed ibuprofen and oxycodone 5 mg/acetaminophen 325 mg as needed for pain. The primary outcome measure was pain. Secondary outcomes were nausea, itching, and daily oxycodone use. Patients were asked to quantify their average pain at rest, nausea, and itching on an 11-point verbal scale (from 0 to 10). These data were recorded for 6 days during daily telephone contacts with patients after hospital discharge.

RESULTS

Cumulative results for 6 days showed significantly lower values in the intervention group compared with the control group for pain (median [interquartile range], 28 [14-35] vs 35 [28-41], respectively; P = .009) and oxycodone use (median [interquartile range] number of tablets, 0 [0-2] vs 8 [1.25-16], respectively; P < .001). Based on these data, the upper tolerance limits for the number of oxycodone tablets required by 90% of patients in the intervention and control groups were 8 tablets and 30 tablets, respectively. Cumulative results for nausea and itching were also significantly lower for the intervention group. Most patients in the intervention group used no opioids during recovery.

CONCLUSION

Simultaneous dosing of 3 nonopioid analgesics resulted in reduced postoperative pain and markedly lower opioid use.

REGISTRATION

NCT04015908 (ClinicalTrials.gov identifier).

Prevalence of Gabapentinoids and Central Nervous System Depressant Drugs, and Their Association with Risk Factors for Respiratory Depression in Primary Care Patients

BACKGROUND AND OBJECTIVES

Warnings have been published regarding an increased risk of severe respiratory depression in patients receiving gabapentinoids either alone or in combination with opioids and/or anxiolytics/hypnotics, especially in individuals with a respiratory risk factor. The aim is to report the prevalence of the use of gabapentinoids alone and associated with central nervous system depressant drugs, and possible associated risk factors for respiratory depression, in order to identify the most fragile population and establish intervention strategies.

METHODS

We performed a cross-sectional study using computerized prescription records from the northern area of Barcelona at Catalan Institute of Health for 363,007 inhabitants registered during 2021. Patients aged ≥ 18 years with one or more gabapentinoid prescription were included. Age, gender, polypharmacy, adjusted morbidity groups, quantity of chronic diseases, and the number of consultations per year were independent variables. Four age categories were defined (18-64 years, then 64-74, 75-84, and those aged 85 years or older). Descriptive and inferential statistics were employed. Level of statistical significance was 5% (p ≤ 0.05). For the analysis, the SPSS program (version 22) was employed.

RESULTS

Of the study sample, 9218 were prescribed gabapentidoids. Overall prevalence of use was 3.0% (women 3.6%, men 2.4%). On the whole, women used more drugs than men. In contrast to their younger counterparts, consumption increased 2.6 times, 3.8 times, and 4.0 times in the 65-74 age group, 75-84 age group, and those aged ≥ 85 years, respectively. Mean age was 65.59 (±15.80) years. Polypharmacy (5-9 drugs) was present in 41.7% of the patients and extreme polypharmacy (≥ 10 drugs) was present in 39.3% of the patients. Regarding renal function, 2396 patients (25.9%) had glomerular filtration that required dose adjustment (76.1% with gabapentin and 23.8% with pregabalin). In 141 patients (5.9%), a total daily dose higher than that authorized (109 with gabapentin, 29 with pregabalin) had been prescribed. The prescription of gabapentinoids combined with opioids and/or anxiolytics/hypnotics was significantly associated with (i) polypharmacy (5-9 drugs, OR: 3.42 [95% CI 3.00-3.88]; ≥ 10 drugs, OR 8.72 [95% CI 7.42-10.25]); (ii) quantity of chronic diseases, OR: 1.14 (95% CI 1.11-1.17); (iii) augmented number of consultations/year, OR: 1.01 (95% CI 1.00-1.01); (iv) female gender, OR: <  1 for men, OR: 0.66 (95% CI 0.60-0.73); (v) being elderly: 65-74 years, OR: 0.71 (95% CI 0.62-0.81); 75-84 years, OR: 0.62 (95% CI 0.54-0.71); ≥85 years, OR: 0.68 (95% CI 0.58-0.81); and (vi) adjusted morbidity groups, OR: 0.90 (95% CI 0.88-0.92), (p <  0.0001).

CONCLUSION

Exposure to gabapentinoids occurs in a non-negligible percentage of the population. Greater numbers of combinations of gabapentinoids and opioids and/or anxiolytics/hypnotics were associated with polypharmacy, quantity of chronic diseases, and augmented number of consultations, but not with male gender, older age, and adjusted morbidity groups.

Association Between Gabapentinoids and Postoperative Pulmonary Complications in Patients Undergoing Thoracic Surgery

OBJECTIVE

Perioperative gabapentinoids in general surgery have been associated with an increased risk of postoperative pulmonary complications (PPCs), while resulting in equivocal pain relief. This study's aim was to examine the utilization of gabapentinoids in thoracic surgery to determine the association of gabapentinoids with PPCs and perioperative opioid utilization.

DESIGN

A multicenter retrospective cohort study.

SETTING

Hospitals in the Premier Healthcare Database from 2012 to 2018.

PARTICIPANTS

A total of 70,336 patients undergoing elective open thoracotomy, video-assisted thoracic surgery, and robotic-assisted thoracic surgery.

INTERVENTIONS

Propensity score analyses were used to assess the association between gabapentinoids on day of surgery and the primary composite outcome of PPCs, defined as respiratory failure, pneumonia, reintubation, pulmonary edema, and noninvasive and invasive ventilation. Secondary outcomes included invasive and noninvasive ventilation, hospital mortality, length of stay, opioid consumption on day of surgery, and average daily opioid consumption after day of surgery.

RESULTS

Overall, 8,142 (12%) patients received gabapentinoids. The prevalence of gabapentin on day of surgery increased from 3.8% in 2012 to 15.9% in 2018. Use of gabapentinoids on day of surgery was associated with greater odds of PPCs (odds ratio [OR] 1.19, 95% CI 1.11-1.28), noninvasive mechanical ventilation (OR 1.30, 95% CI 1.16-1.45), and invasive mechanical ventilation (OR 1.14, 95% CI 1.02-1.28). Secondary outcomes indicated no clinically meaningful associations of gabapentinoid use with opioid consumption, hospital mortality, or length of stay.

CONCLUSIONS

Perioperative gabapentinoid administration in elective thoracic surgery may be associated with a higher risk of PPCs and no opioid-sparing effect.

Tapentadol versus oxycodone analgesia and side effects after laparoscopic hysterectomy: A randomised controlled trial

BACKGROUND

Tapentadol is an opioid, which acts as a μ-opioid receptor agonist and inhibits noradrenaline reuptake in the central nervous system. This dual mechanism of action results in synergistic analgesic effects and potentially less side effects. This has been shown in treatment of chronic pain but postoperative studies are sparse.

OBJECTIVES

The main aim was to compare the analgesic effect of tapentadol with oxycodone after laparoscopic hysterectomy. Opioid side effects were recorded as secondary outcomes.

DESIGN

Randomised, blinded trial.

SETTING

Single-centre, Oslo University Hospital, Norway, December 2017 to February 2019.

PATIENTS

Eighty-six opioid-naïve American Society of Anesthesiologists physical status 1 to 3 women undergoing laparoscopic hysterectomy for nonmalignant conditions.

INTERVENTION

The patients received either oral tapentadol (group T) or oxycodone (group O) as part of multimodal pain treatment. Extended-release study medicine was administered 1 h preoperatively and after 12 h. Immediate-release study medicine was used as rescue analgesia.

MAIN OUTCOME MEASURES

Pain scores, opioid consumption and opioid-induced side effects were evaluated during the first 24 h after surgery.

RESULTS

The groups scored similarly for pain at rest using a numerical rating scale (NRS) 1 h postoperatively (group T 4.4, 95% CI, 3.8 to 5.0, group O 4.6, 95% CI, 3.8 to 5.3). No statistically significant differences were found between the groups for NRS at rest or while coughing during the 24-h follow-up period (P = 0.857 and P = 0.973). Mean dose of oral rescue medicine was similar for the groups (P = 0.914). Group T had significantly lower odds for nausea at 2 and 3 h postoperatively (P = 0.040, P = 0.020) and less need for antiemetics than group O. No differences were found for respiratory depression, vomiting, dizziness, pruritus, headache or sedation.

CONCLUSION

We found tapentadol to be similar in analgesic efficacy to oxycodone during the first 24 h after hysterectomy, but with significantly less nausea.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03314792.

Pain management after complex spine surgery: A systematic review and procedure-specific postoperative pain management recommendations

BACKGROUND

Complex spinal procedures are associated with intense pain in the postoperative period. Adequate peri-operative pain management has been shown to correlate with improved outcomes including early ambulation and early discharge.

OBJECTIVES

We aimed to evaluate the available literature and develop recommendations for optimal pain management after complex spine surgery.

DESIGN AND DATA SOURCES

A systematic review using the PROcedure SPECific postoperative pain managemenT methodology was undertaken. Randomised controlled trials and systematic reviews published in the English language from January 2008 to April 2020 assessing postoperative pain after complex spine surgery using analgesic, anaesthetic or surgical interventions were identified from MEDLINE, EMBASE and Cochrane Databases.

RESULTS

Out of 111 eligible studies identified, 31 randomised controlled trials and four systematic reviews met the inclusion criteria. Pre-operative and intra-operative interventions that improved postoperative pain were paracetamol, cyclo-oxygenase (COX)-2 specific-inhibitors or non-steroidal anti-inflammatory drugs (NSAIDs), intravenous ketamine infusion and regional analgesia techniques including epidural analgesia using local anaesthetics with or without opioids. Limited evidence was found for local wound infiltration, intrathecal and epidural opioids, erector spinae plane block, thoracolumbar interfascial plane block, intravenous lidocaine, dexmedetomidine and gabapentin.

CONCLUSIONS

The analgesic regimen for complex spine surgery should include pre-operative or intra-operative paracetamol and COX-2 specific inhibitors or NSAIDs, continued postoperatively with opioids used as rescue analgesics. Other recommendations are intra-operative ketamine and epidural analgesia using local anaesthetics with or without opioids. Although there is procedure-specific evidence in favour of intra-operative methadone, it is not recommended as it was compared with shorter-acting opioids and due to its limited safety profile. Furthermore, the methadone studies did not use non-opioid analgesics, which should be the primary analgesics to ultimately reduce overall opioid requirements, including methadone. Further qualitative randomised controlled trials are required to confirm the efficacy and safety of these recommended analgesics on postoperative pain relief.

Pharmacologically Induced Ventilatory Depression in the Postoperative Patient: A Sleep-Wake State-Dependent Perspective

Pharmacologically induced ventilatory depression (PIVD) is a common postoperative complication with a spectrum of severity ranging from mild hypoventilation to severe ventilatory depression, potentially leading to anoxic brain injury and death. Recent studies, using continuous monitoring technologies, have revealed alarming rates of previously undetected severe episodes of postoperative ventilatory depression, rendering the recognition of such episodes by the standard intermittent assessment practice, quite problematic. This imprecise description of the epidemiologic landscape of PIVD has thus stymied efforts to understand better its pathophysiology and quantify relevant risk factors for this postoperative complication. The residual effects of various perianesthetic agents on ventilatory control, as well as the multiple interactions of these drugs with patient-related factors and phenotypes, make postoperative recovery of ventilation after surgery and anesthesia a highly complex physiological event. The sleep-wake, state-dependent variation in the control of ventilation seems to play a central role in the mechanisms potentially enhancing the risk for PIVD. Herein, we discuss emerging evidence regarding the epidemiology, risk factors, and potential mechanisms of PIVD.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Respiratory depression in the post-anesthesia care unit: Mayo Clinic experience

The anesthesia recovery is a complex physiologic process as systems recover from the effects of surgery and anesthesia. Inadequate recovery of respiratory physiology can lead to severe hypoxemia-induced end-organ damage and even death. Emerging evidence suggests that signs of respiratory depression during early anesthesia recovery may portend increased risk for future severe adverse events. This article briefly reviews the Mayo Clinic research experience and advances in clinical practice. From the implementation of a step-down model of discharge criteria in the post-anesthesia care unit (PACU), consisting of PACU nurses monitoring patients in predetermined periods for signs of respiratory depression, and delaying PACU discharge for patients who exhibit signs of respiratory depression, and early intervention in high-risk patients. Subsequent studies found that even a single episode of respiratory depression in the PACU was strongly associated with subsequent respiratory complications. Further, patient baseline characteristics found to be associated with respiratory depression included obstructive sleep apnea and low body weight, and surgical factors associated with increased risk included the use of preoperative sustained-release opioids, perioperative gabapentinoid use, higher intraoperative opioids, isoflurane as the volatile anesthetic, and longer surgical duration. Based in part of Mayo Clinic research, the FDA issued a warning in 2019 on gabapentinoids use and respiratory complications, increasing the recommended level of respiratory vigilance in patients using this medication. Understanding the complex nature of postoperative respiratory events requires a range of translational and clinical research and constant update of practice.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Trends in new prescription of gabapentinoids and of coprescription with opioids in the 4 nations of the UK, 1993-2017

We explored potential differences in time trends of gabapentinoid prescription and of opioid coprescription between 1993 and 2017 in the 4 UK nations using the Clinical Practice Research Datalink, a UK primary care database. There were distinct trends in annual rates of new gabapentin and pregabalin prescriptions in Northern Ireland. The rate of new gabapentin prescriptions rapidly increased after 2010 and exceeded that of the other nations by 2017 (rate of 836 [95% confidence interval: 787-887] per 100 000 person-years). Additionally, the rate of new pregabalin prescriptions was higher during the entire study period, reaching a peak of 1139 (95% confidence interval: 1088-1193) per 100 000 person-years in 2010, 5-fold higher than the other nations. Findings in Northern Ireland may be partly attributable to the high burden of anxiety disorders, an indication for pregabalin. Further exploration of reasons for discrepancies in gabapentinoid prescribing between UK nations is warranted.

Optimizing Perioperative Use of Opioids: A Multimodal Approach

PURPOSE OF REVIEW

The main purpose of this article is to review recent literature regarding multimodal analgesia medications, citing their recommended doses, efficacy, and side effects. The second part of this report will provide a description of drugs in different stages of development which have novel mechanisms with less side effects such as tolerance and addiction.

RECENT FINDINGS

Multimodal analgesia is a technique that facilitates perioperative pain management by employing two or more systemic analgesics along with regional anesthesia, when possible. Even though opioids and non-opioid analgesics remain the most common medication used for acute pain management after surgery, they have many undesirable side effects including the potential for misuse. Newer analgesics including peripheral acting opioids, nitric oxide inhibitors, calcitonin gene-related peptide receptor antagonists, interleukin-6 receptor antagonists and gene therapy are under intensive investigation.

SUMMARY

A patient's first exposure to opioids is often in the perioperative setting, a vulnerable time when multimodal therapy can play a large role in decreasing opioid exposure. Additionally, the current shift towards faster recovery times, fewer post-operative complications and improved cost-effectiveness during the perioperative period has made multimodal analgesia a central pillar of Enhanced Recovery After Surgery (ERAS) protocols.

Association of Gabapentinoids With the Risk of Opioid-Related Adverse Events in Surgical Patients in the United States

IMPORTANCE

The use of gabapentinoids in multimodal postoperative analgesia is increasing; however, when coadministered with opioids, these drugs may potentiate central nervous system and respiratory depression.

OBJECTIVE

To evaluate the association between perioperative coadministration of gabapentinoids and opioids with inpatient opioid-related adverse events in surgical patients.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used propensity score trimming, stratification, and weighting of adults admitted for a major surgery between October 2007 and December 2017 who were treated with opioids on the day of surgery and included in the Premier Research database. Data analysis was conducted from February to April 2020.

EXPOSURE

Gabapentinoids (gabapentin or pregabalin) coadministered with opioids starting the day of surgery vs opioid therapy without gabapentinoids.

MAIN OUTCOMES AND MEASURES

Primary outcome was opioid overdose. Secondary outcomes included respiratory complications, unspecified adverse effects of opioid use, and a composite of these 3 outcomes. Patients were followed up for as long as 30 days from the day of surgery until deviation from the initial treatment regimen or discharge.

RESULTS

Gabapentinoids with opioids were administered to 892 484 of 5 547 667 eligible admissions (16.1%; mean [SD] age, 63.5 [11.8] years; 353 315 [39.6%] men). Among the 4 655 183 patients who received opioids only, the mean (SD) age was 63.7 (14.7) years, and 1 913 284 (41.1%) were men. Overall, 441 overdose events were identified, with absolute risks of 1.4 per 10 000 patients with gabapentinoid exposure and 0.7 per 10 000 patients receiving opioids only. Following propensity score trimming, the cohort included 737 383 patients exposed to gabapentinoids and 3 002 480 patients receiving opioids only. The primary analysis yielded the adjusted hazard ratio of 1.95 (95% CI, 1.49-2.55), and the number needed to treat for an additional overdose to occur was 16 914 patients (95% CI, 11 556-31 537 patients). Adjusted hazard ratios for secondary outcomes were 1.68 (95% CI, 1.59-1.78) for respiratory complications, 1.77 (95% CI, 1.61-1.93) for unspecified adverse effects of opioids, and 1.70 (95% CI, 1.62-1.79) for the composite outcome. The results were consistent across sensitivity analyses and subgroups identified by key clinical factors.

CONCLUSIONS AND RELEVANCE

In this real-world cohort study of patients who underwent major surgery, concomitant use of gabapentinoids with opioids was associated with increased risk of opioid overdose and other opioid-related adverse events; however, the absolute risk of adverse events was low.

PROSPECT guideline for tonsillectomy: systematic review and procedure-specific postoperative pain management recommendations

Tonsillectomy is one of the most frequently performed surgical procedures; however, pain management remains challenging. Procedure‐specific efficacy as well as specific risks of treatment options should guide selection of pain management protocols based on evidence and should optimise analgesia without harm. The aims of this systematic review were to evaluate the available literature and develop recommendations for optimal pain management after tonsillectomy. A systematic review utilising preferred reporting items for systematic reviews and meta‐analysis guidelines with procedure‐specific postoperative pain management (PROSPECT) methodology was undertaken. Randomised controlled trials published in the English language up to November 2019 assessing postoperative pain using analgesic, anaesthetic or surgical interventions were identified. Out of the 719 potentially eligible studies identified, 226 randomised controlled trials met the inclusion criteria, excluding the studies examining surgical techniques. Pre‐operative and intra‐operative interventions that improved postoperative pain were paracetamol; non‐steroidal anti‐inflammatory drugs; intravenous dexamethasone; ketamine (only assessed in children); gabapentinoids; dexmedetomidine; honey; and acupuncture. Inconsistent evidence was found for local anaesthetic infiltration; antibiotics; and magnesium sulphate. Limited evidence was found for clonidine. The analgesic regimen for tonsillectomy should include paracetamol; non‐steroidal anti‐inflammatory drugs; and intravenous dexamethasone, with opioids as rescue analgesics. Analgesic adjuncts such as intra‐operative and postoperative acupuncture as well as postoperative honey are also recommended. Ketamine (only for children); dexmedetomidine; or gabapentinoids may be considered when some of the first‐line analgesics are contra‐indicated. Further randomised controlled trials are required to define risk and combination of drugs most effective for postoperative pain relief after tonsillectomy.

Review of nonopioid multimodal analgesia for surgical and trauma patients

Purpose

Pain is a frequent finding in surgical and trauma patients, and effective pain control remains a common challenge in the hospital setting. Opioids have traditionally been the foundation of pain management; however, these agents are associated with various adverse effects and risks of dependence and diversion.

Summary

In response to the rising national opioid epidemic and the various risks associated with opioid use, multimodal pain management through use of nonopioid analgesics such as acetaminophen, nonsteroidal anti-inflammatory drugs, α 2 agonists, N-methyl-d-aspartate (NMDA) receptor antagonists, skeletal muscle relaxants, sodium channel blockers, and local anesthetics has gained popularity recently. Multimodal analgesia has synergistic therapeutic effects and can decrease adverse effects by enabling use of lower doses of each agent in the multimodal regimen. This review discusses properties of the various nonopioid analgesics and encourages pharmacists to play an active role in the selection, initiation, and dose-titration of multimodal analgesia. The choice of nonopioid agents should be based on patient comorbidities, hemodynamic stability, and the agents’ respective adverse effect profiles. A multidisciplinary plan for management of pain should be formulated during transitions of care and is an area of opportunity for pharmacists to improve patient care.

Conclusion

Multimodal analgesia effectively treats pain while decreasing adverse effects. There is mounting evidence to support use of this strategy to decrease opioid use. As medication experts, pharmacists can play a key role in the selection, initiation, and dose-titration of analgesic agents based on patient-specific factors.

Multimorbidity and Critical Care Neurosurgery: Minimizing Major Perioperative Cardiopulmonary Complications

With increasing prevalence of chronic diseases, multimorbid patients have become commonplace in the neurosurgical intensive care unit (neuro-ICU), offering unique management challenges. By reducing physiological reserve and interacting with one another, chronic comorbidities pose a greatly enhanced risk of major postoperative medical complications, especially cardiopulmonary complications, which ultimately exert a negative impact on neurosurgical outcomes. These premises underscore the importance of perioperative optimization, in turn requiring a thorough preoperative risk stratification, a basic understanding of a multimorbid patient’s deranged physiology and a proper appreciation of the potential of surgery, anesthesia and neurocritical care interventions to exacerbate comorbid pathophysiologies. This knowledge enables neurosurgeons, neuroanesthesiologists and neurointensivists to function with a heightened level of vigilance in the care of these high-risk patients and can inform the perioperative neuro-ICU management with individualized strategies able to minimize the risk of untoward outcomes. This review highlights potential pitfalls in the intra- and postoperative neuro-ICU period, describes common preoperative risk stratification tools and discusses tailored perioperative ICU management strategies in multimorbid neurosurgical patients, with a special focus on approaches geared toward the minimization of postoperative cardiopulmonary complications and unplanned reintubation.

Perioperative Gabapentinoids: Deflating the Bubble

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Multimodal Pain Management and Postoperative Outcomes in Lumbar Spine Fusion Surgery: A Population-based Cohort Study

STUDY DESIGN

Retrospective population-based cohort analysis.

OBJECTIVE

Given the lack of large-scale data on the use and efficacy of multimodal analgesia in spine fusion surgery, we conducted a population-based analysis utilizing the nationwide claims-based Premier Healthcare database.

SUMMARY OF BACKGROUND DATA

Multimodal analgesia, combining different pain signaling pathways to achieve additive and synergistic effects, is increasingly emerging as the standard of care.

METHODS

Cases of posterior lumbar fusion surgery were extracted (2006-2016). Opioid-only analgesia was compared to multimodal analgesia, that is, systemic opioid analgesia + either acetaminophen, steroids, gabapentinoids, ketamine, nonsteroidal anti-inflammatory drugs (NSAIDs), cyclooxygenase-2 (COX-2) inhibitors, or neuraxial anesthesia (categorized into 1, 2, or >2 additional analgesic modes). Mixed-effects models measured associations between multimodal analgesia categories and outcomes, including opioid prescription dose, cost/length of hospitalization, and opioid-related complications. Odds ratios (ORs, or % change) and 95% confidence intervals (CIs) are reported.

RESULTS

Among 265,538 patients the incidence of multimodal analgesia was 61.1% (162,156); multimodal pain management-specifically when adding NSAIDs/COX-2 inhibitors to opioids-was associated with reduced opioid prescription (-13.3% CI -16.7 to -9.7%), cost (-2.9% CI -3.9 to -1.8%) and length of hospitalization (-7.3% CI -8.5 to -6.1%). Multimodal analgesia in general was associated with stepwise decreased odds for gastrointestinal complications (OR 0.95, 95% CI 0.88-1.04; OR 0.84, CI 0.75-0.95; OR 0.78, 95% CI 0.64-0.96), whereas odds were increased for postoperative delirium (OR 1.14, 95% CI 1.00-1.32; OR 1.33, 95% CI 1.11-1.59; OR 1.31, 95% CI 0.99-1.74), and counterintuitively- naloxone administration (OR 1.25, 95% CI 1.13-1.38; OR 1.56, 95% CI 1.37-1.77; OR 1.84, 95% CI 1.52-2.23) with increasing analgesic modes used: one, two, or more additional analgesic modes, respectively. Post-hoc analysis revealed that specifically gabapentinoid use increased odds of naloxone requirement by about 50%, regardless of concurrent opioid dose (P < 0.001).

CONCLUSION

Although multimodal analgesia was not consistently implemented in spine fusion surgery, particularly NSAIDs and COX-2 inhibitors demonstrated opioid sparing effects. Moreover, results suggest a synergistic interaction between gabapentinoids and opioids, the former potentiating opioid effects resulting in greater naloxone requirement.

LEVEL OF EVIDENCE

3.

Gabapentinoids: pharmacokinetics, pharmacodynamics and considerations for clinical practice

The gabapentinoids are often recommended as first-line treatments for the management of neuropathic pain. The differing pharmacodynamic and pharmacokinetic profiles can have implications for clinical practice. This article has summarised these key differences. In addition to their use in managing neuropathic pain, gabapentinoids are increasingly being used for off-label conditions despite the lack of evidence. Prescription rates for off-label conditions have overtaken that for on-label use. Similarly, the use of gabapentinoids in the perioperative period is now embedded in clinical practice despite conflicting evidence. This article summarises the risks associated with this increasing use. There is increasing evidence of the potential to cause harm in vulnerable populations such as the elderly and increasing prevalence of abuse. The risk of respiratory depression in combination with opioids is of particular concern in the context of the current opioid crisis. This article describes the practical considerations involved that might help guide appropriate prescribing practices.

Effects of Acetaminophen, NSAIDs, Gabapentinoids, and Their Combinations on Postoperative Pulmonary Complications After Total Hip or Knee Arthroplasty

Objective

Multimodal analgesia has gained popularity in total hip arthroplasty (THA) and total knee arthroplasty (TKA), but large multicenter studies evaluating specific analgesic combinations are lacking.

Design

A retrospective study using the Premier Healthcare Database (2009–2014).

Subjects

Adults who underwent elective primary THA or TKA.

Methods

We categorized day-of-surgery analgesic exposure using eight mutually exclusive categories: acetaminophen (Ac), nonsteroidal anti-inflammatory drugs (Ns), gabapentinoids (Ga; gabapentin or pregabalin), Ac+Ns, Ac+Ga, Ns+Ga, Ac+Ns+Ga, and none of the three drugs. Multilevel models measured associations of the analgesic categories with a composite of postoperative pulmonary complications (PPCs).

Results

Among 863,139 patients, 75.2% received at least one of the three drugs. In multilevel models, compared with none of the three drugs, Ga use was associated with increased odds of PPCs when used alone (adjusted odds ratio [aOR] = 1.35, 95% confidence interval [CI] = 1.27 to 1.44), combined with Ac (aOR = 1.16, 95% CI = 1.08 to 1.26), or combined with Ns (aOR = 1.28, 95% CI = 1.21 to 1.34). In contrast, the Ac+Ns pair was associated with decreased odds of PPCs (OR = 0.86, 95% CI = 0.83 to 0.90) and lower opioid consumption. Ac+Ns+Ga was not associated with PPCs, whereas it was associated with the lowest opioid consumption on the day of surgery.

Conclusions

Gabapentinoids, alone and in single combination with either acetaminophen or nonsteroidal anti-inflammatory drugs, were associated with higher PPCs, whereas the Ac+Ns pair was associated with fewer PPCs and an opioid-sparing effect. Ac+Ns+Ga was not associated with PPCs, whereas it was associated with the lowest opioid consumption on the day of surgery.

Risk factors for postoperative delirium in patients undergoing lower extremity joint arthroplasty: a retrospective population-based cohort study

BACKGROUND

With an ageing population, the demand for joint arthroplasties and the burden of postoperative delirium is likely to increase. Given the lack of large-scale data, we investigated associations between perioperative risk factors and postoperative delirium in arthroplasty surgery.

METHODS

This retrospective population-based cohort study, utilized national claims data from the all-payer Premier Healthcare database containing detailed billing information from >25% nationwide hospitalizations. Patients undergoing elective total hip/knee arthroplasty surgery (2006-2016) were included.The primary outcome was postoperative delirium, while potential risk factors included age, gender, race, insurance type, and modifiable exposures including anesthesia type, opioid prescription dose (low/medium/high), benzodiazepines, meperidine, non-benzodiazepine hypnotics, ketamine, corticosteroids, and gabapentinoids.

RESULTS

Among 1 694 795 patients' postoperative delirium was seen in 2.6% (14 785/564 226) of hip and 2.9% (32 384/1 130 569) of knee arthroplasties. Multivariable models revealed that the utilization of long acting (OR 2.10 CI 1.82 to 2.42), combined long/short acting benzodiazepines (OR 1.74 CI 1.56 to 1.94), and gabapentinoids (OR 1.26 CI 1.16 to 1.36) was associated with increased odds of postoperative delirium. Lower odds of postoperative delirium were seen for neuraxial versus general anesthesia (OR 0.81 CI 0.70 to 0.93) and with the utilization of non-steroidal anti-inflammatory drugs (OR 0.85 CI 0.79 to 0.91) as well as cyclooxygenase-2 inhibitors (OR 0.82 CI 0.77 to 0.89). Age-stratified analysis revealed lower odds with high versus low opioid dose (OR 0.86 CI 0.76 to 0.98) in patients >65 years. Findings were consistent between hip and knee arthroplasties.

CONCLUSIONS

In this large national cohort, we identified various modifiable risk factors (including anesthesia type and pharmaceutical agents) for postoperative delirium, demonstrating possible prevention pathways.

Risk-based targeting of adjuvant pregabalin treatment in laparoscopic cholecystectomy: a randomized, controlled trial

Background and aims Pain is the most common reason for delayed discharge after day-case laparoscopic cholecystectomy. This study investigates a simple five-item questionnaire in evaluating the risk of postoperative pain in day-case cholecystectomy and the efficacy and safety of single-dose preoperative pregabalin on patients with multiple risk factors for pain. There are no previous studies on targeting adjuvant pain treatment based on the individual risk factors like the preoperative state of anxiety, acute or chronic pain, and the expectation of pain in day-case surgery. Methods One hundred and thirty patients scheduled for day-case laparoscopic cholecystectomy were evaluated with a five-item questionnaire assessing the risk for postoperative pain. The patients with multiple risk factors (n=60) were randomized to receive either pregabalin 150 mg or placebo, 1 h before surgery. The primary outcome was abdominal pain intensity on numerical rating scale (NRS) 1 h after surgery. Pain, analgesic consumption and adverse effects during first three postoperative days, and the length of hospital stay were also recorded. Results Pregabalin 150 mg given as an adjuvant analgesic preoperatively did not decrease postoperative abdominal pain or opioid consumption in the first hour after surgery compared to placebo in a preselected group of patients with multiple risk factors for postoperative pain (p=0.31). Preoperative anxiety assessed with a scale of 0-10 had a positive association with postoperative pain (p=0.045). Conclusions and implications This was the first trial on systematically selecting patients with a high-risk factor profile for postoperative pain as a target for a preventive adjuvant analgesic intervention. Although numerous previous studies have identified various risk factors, including those used in the current trial, it seems to be challenging to use these risk factors as predictive tools for targeting adjuvant analgesics in day-case surgery. Preoperative anxiety has a positive association with postoperative pain in day-case laparoscopic cholecystectomy, and this should be taken into account when treating these patients.

Prevention and Treatment of Chronic Postsurgical Pain: A Narrative Review

Chronic postsurgical pain affects between 5 and 75% of patients, often with an adverse impact on quality of life. While the transition of acute to chronic pain is a complex process-involving multiple mechanisms at different levels-the current strategies for prevention have primarily been restricted to perioperative pharmacological interventions. In the present paper, we first present an up-to-date narrative literature review of these interventions. In the second section, we develop several ways by which we could overcome the limitations of the current approaches and enhance the outcome of our surgical patients, including the better identification of individual risk factors, tailoring treatment to individual patients, and improved acute and subacute pain evaluation and management. The third and final section covers the treatment of established CPSP. Given that evidence for the current therapeutic options is limited, we need high-quality trials studying multimodal interventions matched to pain characteristics.

Chronic Pain and Chronic Opioid Use After Intensive Care Discharge - Is It Time to Change Practice?

Almost half of patients treated on intensive care unit (ICU) experience moderate to severe pain. Managing pain in the critically ill patient is challenging, as their pain is complex with multiple causes. Pharmacological treatment often focuses on opioids, and over a prolonged admission this can represent high cumulative doses which risk opioid dependence at discharge. Despite analgesia the incidence of chronic pain after treatment on ICU is high ranging from 33-73%. Measures need to be taken to prevent the transition from acute to chronic pain, whilst avoiding opioid overuse. This narrative review discusses preventive measures for the development of chronic pain in ICU patients. It considers a number of strategies that can be employed including non-opioid analgesics, regional analgesia, and non-pharmacological methods. We reason that individualized pain management plans should become the cornerstone for critically ill patients to facilitate physical and psychological well being after discharge from critical care and hospital.

Cognitive Effects of Perioperative Pregabalin

EDITOR’S PERSPECTIVE

What We Already Know about This Topic

Perioperative administration of pregabalin has been associated with decreased postoperative pain and opioid requirements

What This Article Tells Us That Is New

This secondary analysis of data demonstrating that perioperative administration of pregabalin was associated with a reduction in opioid requirements and incisional hyperalgesia suggests that these benefits may be compromised by an increased risk of developing impaired postoperative cognitive performance

Background

Pregabalin has shown opioid sparing and analgesic effects in the early postoperative period; however, perioperative effects on cognition have not been studied. A randomized, parallel group, placebo-controlled investigation in 80 donor nephrectomy patients was previously performed that evaluated the analgesic, opioid-sparing, and antihyperalgesic effects of pregabalin. This article describes a secondary exploratory analysis that tested the hypothesis that pregabalin would impair cognitive function compared to placebo.

Methods

Eighty patients scheduled for donor nephrectomy participated in this randomized, placebo-controlled study. Pregabalin (150 mg twice daily, n = 40) or placebo (n = 40) was administered on the day of surgery and the first postoperative day, in addition to a pain regimen consisting of opioids, steroids, local anesthetics, and acetaminophen. Specific cognitive tests measuring inhibition, sustained attention, psychomotor speed, visual memory, and strategy were performed at baseline, 24 h, and 3 to 5 days after surgery, using tests from the Cambridge Neuropsychological Test Automated Battery.

Results

In the spatial working memory within errors test, the number of errors increased with pregabalin compared to placebo 24 h after surgery; median (25th, 75th percentile) values were 1 (0, 6) versus 0 (0, 1; rate ratio [95% CI], 3.20 [1.55 to 6.62]; P = 0.002). Furthermore, pregabalin significantly increased the number of errors in the stop-signal task stop-go test compared with placebo; median (25th, 75th percentile) values were 3 (1, 6) versus 1 (0, 2; rate ratio, 2.14 [1.13 to 4.07]; P = 0.020). There were no significant differences between groups in the paired associated learning, reaction time, rapid visual processing, or spatial working memory strategy tests.

Conclusions

Perioperative pregabalin significantly negatively affected subdomains of executive functioning, including inhibition, and working memory compared to placebo, whereas psychomotor speed was not changed.

Updates on Multimodal Analgesia for Orthopedic Surgery

Pain control after orthopedic surgery is challenging. A multimodal approach provides superior analgesia with fewer side effects compared with opioids alone. This approach is particularly useful in light of the current opioid epidemic in the United States. Several new nonopioid agents have emerged into the market in recent years. New agents included in this review are intravenous acetaminophen, intranasal ketorolac, and newer nonsteroidal anti-inflammatory drugs, and the established medications ketamine and gabapentinoids. This article evaluates the evidence supporting these drugs in a multimodal context, including a brief discussion of cost.

Post-Operative Cognitive Dysfunction: An exploration of the inflammatory hypothesis and novel therapies

Post-Operative Cognitive Dysfunction (POCD) is a highly prevalent condition with significant clinical, social and financial impacts for patients and their communities. The underlying pathophysiology is becoming increasingly understood, with the role of neuroinflammation and oxidative stress secondary to surgery and anaesthesia strongly implicated. This review aims to describe the putative mechanisms by which surgery-induced inflammation produces cognitive sequelae, with a focus on identifying potential novel therapies based upon their ability to modify these pathways.

Pregabalin reduces opioid consumption and hyperalgesia but not pain intensity after laparoscopic donor nephrectomy

BACKGROUND

Gabapentinoids are increasingly used to reduce acute postoperative pain, opioid consumption and opioid-related adverse effects. We explored the opioid-sparing, analgesic and anti-hyperalgesic effect of perioperative administered pregabalin in laparoscopic living donor nephrectomy.

METHODS

In this randomized controlled trial, 80 patients were recruited and randomized to receive pregabalin 150 mg twice daily or placebo on the day of surgery and the first postoperative day as part of a multimodal analgesic regimen. Primary outcome was opioid consumption 0-48 h after surgery. Secondary outcomes were pain intensity at rest and with movement 0-48 h after surgery using the 0-10 Numeric Rating Scale and incisional hyperalgesia measured 24 h post-surgery and at hospital discharge. Further secondary outcomes were adverse effects. Persistent post-surgical pain was registered 6 weeks, 6 and 12 months after surgery.

RESULTS

Pregabalin significantly reduced opioid consumption compared with placebo 0-48 h after surgery (median mg [25th, 75th percentile]); 29.0 (22.0-45.5) vs. 41.8 (25.8-63.6) (P = 0.04). Pain intensity 0-48 h after surgery calculated as area under the pain (NRS) vs. time curve was not statistically different between groups at rest (P = 0.12) or with movement (P = 0.21). Pregabalin decreased incisional hyperalgesia 24 h after surgery (median cm [25th, 75th percentile] 8.5 (1.0-18.5) vs. 15.5 (9.5-24.0) (P = 0.02). Nausea (P ≤ 0.01), use of antiemetics (P ≤ 0.01) and pain-related sleep interference (P = 0.02) were reduced with pregabalin.

CONCLUSIONS

Perioperative pregabalin added to a multimodal analgesic regimen was opioid-sparing, but made no difference to pain intensity score 0-48 h after surgery. Pregabalin may reduce incisional hyperalgesia on the first day after surgery.