Genetics of perioperative pain management

The influence of COMT and ABCB1 gene polymorphisms on sufentanil analgesic effect for postoperative pain in children with fracture

The aim of this observational study was to investigate the effects of catechol-O-methyltransferase (COMT) and ATP-binding cassette transporter B1 (ABCB1) gene polymorphisms on the postoperative analgesic effect of sufentanil in Chinese Han pediatric patients with fractures. A total of 185 pediatric patients who underwent fracture surgery were included. Polymerase chain reaction-restriction fragment length polymorphism was used to detect the polymorphisms of COMT and ABCB1 genes. Sufentanil was used for postoperative analgesia. The pain level of the patients was evaluated using the face, legs, activity, cry, and consolability scale before surgery, during awakening, at 2, 6, 12, and 24 hours after surgery. The postoperative Ramsay sedation score, sufentanil consumption, and incidence of adverse reactions were also recorded. Pediatric patients with different genotypes of ABCB1 and COMT showed no statistically significant differences in general data such as age, gender, weight, height, surgical duration, and American Society of Anesthesiologists classification (P > .05). There were no statistically significant differences in sedation scores after surgery between different genotypes of ABCB1 and COMT (P > .05). Among patients with CC genotype in ABCB1, the pain scores and total consumption of sufentanil at awakening, 2 and 6 hours after surgery were higher compared to TT and CT genotypes (P < .05), while there were no statistically significant differences between TT and CT genotypes (P > .05). Among patients with AA genotype in COMT, the pain scores and total consumption of sufentanil at awakening, 2, 6, 12, and 24 hours after surgery were higher compared to AG and GG genotypes (P < .05), while there were no statistically significant differences between AG and GG genotypes (P > .05). There were no statistically significant differences in adverse reactions between different genotypes of ABCB1 and COMT (P > .05). The polymorphisms of COMT gene rs4680 and ABCB1 gene rs1045642 are associated with the analgesic effect and consumption of sufentanil in pediatric patients after fracture surgery.

Objectively measured activity is not associated with average pain intensity 1 week after surgery: A cross-sectional study

BACKGROUND

Measures of physical activity and pain-related patient-reported outcomes are important components of patient recovery after surgery. However, little is known about their association in the early post-operative period. This study aims to increase this knowledge. Our primary objective was to determine the association between average pain intensity and activity (in steps) 1 week after surgery. Secondary objectives were the association of activity with other patient-reported outcomes, age, sex, comorbidities and body mass index.

METHODS

Data were obtained from the PROMPT sub-project of IMI-PainCare. Patients after breast and endometriosis-related surgery, sternotomy and total knee arthroplasty completed pain-related outcomes questionnaires and wore an ActiGraph activity-tracking device. We correlated steps with average pain intensity on post-operative days 6 and 7. Secondary analyses were done using correlations and t-tests.

RESULTS

In 284 cases, there was no statistically significant correlation between steps and average pain intensity. In addition, none of the 28 secondary analyses showed a statistically significant result.

CONCLUSIONS

Pain-related patient-reported outcome measures and physical activity are separate entities. Both should be measured after surgery to assess patient recovery and to identify treatment deficiencies.

SIGNIFICANCE STATEMENT

Measuring recovery is a multi-dimensional challenge. After surgery, clinicians need to be aware that neither pain intensity nor activity levels tell the whole story. Each can hint to problems and treatment requirements.

Mechanisms of pain in aging and age-related conditions: Focus on caregivers

Pain is a complex, subjective experience that can significantly impact quality of life, particularly in aging individuals, by adversely affecting physical and emotional well-being. Whereas acute pain usually serves a protective function, chronic pain is a persistent pathological condition that contributes to functional deficits, cognitive decline, and emotional disturbances in the elderly. Despite substantial progress that has been made in characterizing age-related changes in pain, complete mechanistic details of pain processing mechanisms in the aging patient remain unknown. Pain is particularly under-recognized and under-managed in the elderly, especially among patients with Alzheimer's disease (AD), Alzheimer's disease-related dementias (ADRD), and other age-related conditions. Furthermore, difficulties in assessing pain in patients with AD/ADRD and other age-related conditions may contribute to the familial caregiver burden. The purpose of this article is to discuss the mechanisms and risk factors for chronic pain development and persistence, with a particular focus on age-related changes. Our article also highlights the importance of caregivers working with aging chronic pain patients, and emphasizes the urgent need for increased legislative awareness and improved pain management in these populations to substantially alleviate caregiver burden.

Predictive models for fentanyl dose requirement and postoperative pain using clinical and genetic factors in patients undergoing major breast surgery

ABSTRACT

Fentanyl exhibits interindividual variability in its dose requirement due to various nongenetic and genetic factors such as single nucleotide polymorphisms (SNPs). This study aims to develop and cross-validate robust predictive models for postoperative fentanyl analgesic requirement and other related outcomes in patients undergoing major breast surgery. Data regarding genotypes of 10 candidate SNPs, cold pain test (CPT) scores, pupillary response to fentanyl (PRF), and other common clinical characteristics were recorded from 257 patients undergoing major breast surgery. Predictive models for 24-hour fentanyl requirement, 24-hour pain scores, and time for first analgesic (TFA) in the postoperative period were developed using 4 different algorithms: generalised linear regression model, linear support vector machine learning (SVM-Linear), random forest (RF), and Bayesian regularised neural network. The variant genotype of OPRM1 (rs1799971) and higher CPT scores were associated with higher 24-hour postoperative fentanyl consumption, whereas higher PRF and history of hypertension were associated with lower fentanyl requirement. The variant allele of COMT (rs4680) and higher CPT scores were associated with 24-hour postoperative pain scores. The variant genotype of CTSG (rs2070697), higher intraoperative fentanyl use, and higher CPT scores were associated with significantly lower TFA. The predictive models for 24-hour postoperative fentanyl requirement, pain scores, and TFA had R-squared values of 0.313 (SVM-Linear), 0.434 (SVM-Linear), and 0.532 (RF), respectively. We have developed and cross-validated predictive models for 24-hour postoperative fentanyl requirement, 24-hour postoperative pain scores, and TFA with satisfactory performance characteristics and incorporated them in a novel web application.

Genetic and epigenetic mechanisms influencing acute to chronic postsurgical pain transitions in pediatrics: Preclinical to clinical evidence

Background

Chronic postsurgical pain (CPSP) in children remains an important problem with no effective preventive or therapeutic strategies. Recently, genomic underpinnings explaining additional interindividual risk beyond psychological factors have been proposed.

Aims

We present a comprehensive review of current preclinical and clinical evidence for genetic and epigenetic mechanisms relevant to pediatric CPSP.

Methods

Narrative review.

Results

Animal models are relevant to translational research for unraveling genomic mechanisms. For example, Cacng2, p2rx7, and bdnf mutant mice show altered mechanical hypersensitivity to injury, and variants of the same genes have been associated with CPSP susceptibility in humans; similarly, differential DNA methylation (H1SP) and miRNAs (miR-96/7a) have shown translational implications. Animal studies also suggest that crosstalk between neurons and immune cells may be involved in nociceptive priming observed in neonates. In children, differential DNA methylation in regulatory genomic regions enriching GABAergic, dopaminergic, and immune pathways, as well as polygenic risk scores for enhanced prediction of CPSP, have been described. Genome-wide studies in pediatric CPSP are scarce, but pathways identified by adult gene association studies point to potential common mechanisms.

Conclusions

Bench-to-bedside genomics research in pediatric CPSP is currently limited. Reverse translational approaches, use of other -omics, and inclusion of pediatric/CPSP endophenotypes in large-scale biobanks may be potential solutions. Time of developmental vulnerability and longitudinal genomic changes after surgery warrant further investigation. Emergence of promising precision pain management strategies based on gene editing and epigenetic programing emphasize need for further research in pediatric CPSP-related genomics.

A Narrative Review on Perioperative Pain Management Strategies in Enhanced Recovery Pathways-The Past, Present and Future

Effective pain management is a key component in the continuum of perioperative care to ensure optimal outcomes for surgical patients. The overutilization of opioids in the past few decades for postoperative pain control has been a major contributor to the current opioid epidemic. Multimodal analgesia (MMA) and enhanced recovery after surgery (ERAS) pathways have been repeatedly shown to significantly improve postoperative outcomes such as pain, function and satisfaction. The current review aims to examine the history of perioperative MMA strategies in ERAS and provide an update with recent evidence. Furthermore, this review details recent advancements in personalized pain medicine. We speculate that the next important step for improving perioperative pain management could be through incorporating these personalized metrics, such as clinical pharmacogenomic testing and patient-reported outcome measurements, into ERAS program.

Pediatric obstructive sleep apnea revisited: Perioperative considerations for the pediatric Anesthesiologist

Pediatric obstructive sleep apnea presents in up to 7% of children and represents a constellation from nasal turbulence to cessation in gas exchange. There are numerous end organ sequelae including neurocognitive morbidity associated with persistent OSA. Adenotonsillectomy (AT), the first line therapy for pediatric OSA, has not been demonstrated to reduce all end organ morbidity, specifically neurological and behavioral morbidity. Furthermore, certain at-risk populations are at higher risk from neurocognitive morbidity. Precise knowledge and perioperative planning is required to ensure optimal evidence-based practices in children with OSA. This comprehensive review covers the seminal perioperative implications of OSA, including preoperative polysomnography, pharmacotherapeutics, and postoperative risk stratification.

Managing rebound pain after regional anesthesia

Rebound pain after regional anesthesia can be defined as transient acute postoperative pain that ensues following resolution of sensory blockade, and is clinically significant, either with regard to the intensity of pain or the impact on psychological well-being, quality of recovery, and activities of daily living. Current evidence suggests that it represents an unmasking of the expected nociceptive response in the absence of adequate systemic analgesia, rather than an exaggerated hyperalgesic phenomenon induced by local anesthetic neural blockade. In the majority of patients, it does not appear to significantly impact cumulative postoperative opioid consumption, quality of recovery, or patient satisfaction, and is not associated with longer-term sequelae such as persistent post-surgical pain. Nevertheless, it must be considered whenever regional anesthesia is incorporated into perioperative management. Strategies to mitigate the impact of rebound pain include routine prescribing of a systemic multimodal analgesic regimen, as well as patient education on appropriate expectations regarding block offset and expected surgical pain, and timely initiation of analgesic medication. Prolonging the duration of action of regional anesthesia with continuous catheter techniques or local anesthetic adjuncts may also help alleviate rebound pain, although further research is required to confirm this.

Genomics testing and personalized medicine in the preoperative setting: Can it change outcomes in postoperative pain management?

Postoperative pain and opioid use are major challenges in perioperative medicine. Pain perception and its response to opioid use are multi-faceted and include pharmacological, psychological, and genetic components. Precision medicine is a unique approach to individualized health care in which decisions in management are based on genetics, lifestyle, and environment of each person. Genetic variations can have an impact on the perception of pain and response to treatment. This can have an effect on pain management in both acute and chronic settings. Although there is currently not enough evidence for making recommendations about genetic testing to guide pain management in the acute care setting, there are some known polymorphisms that play a role in surgical pain and opioid-related postoperative adverse outcomes. In this review, we describe the potential use of pharmacogenomics (PGx) for improving perioperative pain management. We first review a number of genotypes that have shown correlations with pain and opioid use and then describe the importance of PGx-guided analgesic protocols and implementation of screening in a preoperative evaluation clinical setting.

Genetic Polymorphisms of Cytokines Might Affect Postoperative Sufentanil Dosage for Analgesia in Patients

Objective

To explore the effect of genetic polymorphisms of cytokines on the dosage of sufentanil for patient-controlled intravenous analgesia (PCIA) after radical lung cancer surgery.

Methods

A total of 100 patients, aged 18 years and above, with ASA grade Ⅰ-Ⅱ and body mass index (BMI) 18.5 to 30, and who were scheduled for radical lung cancer surgery under total intravenous anaesthesia with PCIA of sufentanil from September 2015 to March 2016, were selected. DNA was collected from peripheral blood samples before surgery, and the iMLDRTM multiple single-nucleotide polymorphism typing kit was used to detect 16 related single-nucleotide polymorphism (SNP) sites of interleukin-1A (IL-1A), interleukin-1β (IL-1β), interleukin-1RN (IL-1RN), interleukin-6 (IL-6), C-X-C motif chemokine ligand 8 (CXCL8), interleukin-10 (IL-10), tumour necrosis factor (TNF), nuclear factor kappa-B1 (NFκB1), REL (REL proto-oncogene, NF-kB subunit), and nuclear factor kappa-B inhibitor alpha (NFκBIA). The general characteristics of patients, surgery and anaesthesia data, postoperative resting VAS pain scores, postoperative opioid dosages of sufentanil for PCIA and opioid-related adverse events were recorded. The effects of the examined genetic polymorphisms of the cytokines on the dosage of sufentanil were analysed.

Results

Eight of 100 patients withdrew for various reasons, and, eventually, 92 patients were included. The patients’ resting visual analogue scale (VAS) scores at 24 h, 48 h, and 72 h after surgery were 2.3 ± 1.2, 2.0 ± 0.9, and 1.9 ± 1.0, respectively. The total amounts of sufentanil used were 34.7 ± 10.5 μg, 65.2 ± 13.7 μg, and 94.7 ± 11.6 μg, respectively. We found that the TT genotype of NFκBIA rs696 had higher PCIA sufentanil dosages than the CC genotype and the CT genotype at 48–72 h postoperation (p=0.023, p=0.025, respectively).

Conclusion

The genetic polymorphisms of the cytokine NFκBIA rs696 might affect the dosage of sufentanil for PCIA after radical lung cancer surgery. The specific mechanism needs further study.

Opioid Prescribing After Surgery in the United States, Canada, and Sweden

IMPORTANCE

Small studies and anecdotal evidence suggest marked differences in the use of opioids after surgery internationally; however, this has not been evaluated systematically across populations receiving similar procedures in different countries.

OBJECTIVE

To determine whether there are differences in the frequency, amount, and type of opioids dispensed after surgery among the United States, Canada, and Sweden.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included patients without previous opioid prescriptions aged 16 to 64 years who underwent 4 low-risk surgical procedures (ie, laparoscopic cholecystectomy, laparoscopic appendectomy, arthroscopic knee meniscectomy, and breast excision) between January 2013 and December 2015 in the United States, between July 2013 and March 2016 in Canada, and between January 2013 and December 2014 in Sweden. Data analysis was conducted in all 3 countries from July 2018 to October 2018.

MAIN OUTCOMES AND MEASURES

The main outcome was postoperative opioid prescriptions filled within 7 days after discharge; the percentage of patients who filled a prescription, the total morphine milligram equivalent (MME) dose, and type of opioid dispensed were compared.

RESULTS

The study sample consisted of 129 379 patients in the United States, 84 653 in Canada, and 9802 in Sweden. Overall, 52 427 patients (40.5%) in the United States were men, with a mean (SD) age of 45.1 (12.7) years; in Canada, 25 074 patients (29.6%) were men, with a mean (SD) age of 43.5 (13.0) years; and in Sweden, 3314 (33.8%) were men, with a mean (SD) age of 42.5 (13.0). The proportion of patients in Sweden who filled an opioid prescription within the first 7 days after discharge for any procedure was lower than patients treated in the United States and Canada (Sweden, 1086 [11.1%]; United States, 98 594 [76.2%]; Canada, 66 544 [78.6%]; P < .001). For patients who filled a prescription, the mean (SD) MME dispensed within 7 days of discharge was highest in United States (247 [145] MME vs 169 [93] MME in Canada and 197 [191] MME in Sweden). Codeine and tramadol were more commonly dispensed in Canada (codeine, 26 136 patients [39.3%]; tramadol, 12 285 patients [18.5%]) and Sweden (codeine, 170 patients [15.7%]; tramadol, 315 patients [29.0%]) than in the United States (codeine, 3210 patients [3.3%]; tramadol, 3425 patients [3.5%]).

CONCLUSIONS AND RELEVANCE

The findings indicate that the United States and Canada have a 7-fold higher rate of opioid prescriptions filled in the immediate postoperative period compared with Sweden. Of the 3 countries examined, the mean dose of opioids for most surgical procedures was highest in the United States.