Chronic morphine administration delays wound healing by inhibiting immune cell recruitment to the wound site

The Impact of Nonpharmacological Interventions on Opioid Use for Chronic Noncancer Pain: A Scoping Review

Despite the lack of evidence, opioids are still routinely used as a solution to long-term management for chronic noncancer pain (CNCP). Given the significant risks associated with long-term opioid use, including the increased number of unregulated opioid pills at large in the opioid ecosystem, opioid cessation or reduction may be the desired goal of the patient and clinician. Viable nonpharmacological interventions (NPIs) to complement and/or replace opioids for CNCP are needed. Comprehensive reviews that address the impact of NPIs to help adults with CNCP reduce opioid use safely are lacking. We conducted a literature search in PubMed, CINAHL, Embase, PsycINFO, and Scopus for studies published in English. The initial search was conducted in April 2021, and updated in January 2024. The literature search yielded 19,190 relevant articles. Thirty-nine studies met the eligibility criteria and underwent data extraction. Of these, nineteen (49%) were randomized controlled trials, eighteen (46%) were observational studies, and two (5%) were secondary analyses. Among adults with CNCP who use opioids for pain management, studies on mindfulness, yoga, educational programs, certain devices or digital technology, chiropractic, and combination NPIs suggest that they might be an effective approach for reducing both pain intensity and opioid use, but other NPIs did not show a significant effect (e.g., hypnosis, virtual reality). This review revealed there is a small to moderate body of literature demonstrating that some NPIs might be an effective and safe approach for reducing pain and opioid use, concurrently.

Opioids and Cancer: Current Understanding and Clinical Considerations

Pain is one of the most common symptoms in patients with cancer. Pain not only negatively affects the quality of life of patients with cancer, but it has also been associated with reduced survival. Pain management is therefore a critical component of cancer care. Prescription opioids remain the first-line approach for the management of moderate-to-severe pain associated with cancer. However, there has been increasing interest in understanding whether these analgesics could impact cancer progression. Furthermore, epidemiological data link a possible association between prescription opioid usage and cancer development. Until more robust evidence is available, patients with cancer with moderate-to-severe pain may receive opioids to decrease suffering. However, future studies should be conducted to evaluate the role of opioids and opioid receptors in specific cancers.

Predictive factors of thoracic aortic calcification in patients candidate for cardiac surgery

BACKGROUND

The presence of the severe thoracic aortic calcification (TAC) in cardiac surgery patients is associated with adverse post-operative outcome. However, the relationship between cardiovascular risk factors and aortic plaque burden remains unknown. The objective of this study was to determine the predictive factors of TAC in patients candidate for cardiac surgery.

METHODS

Patients who underwent thoracic CT scan prior to cardiac surgery between August 2020 to April 2021 were included. Of 556 patients, 209 (36.7%) had a thoracic aortic calcium score (TACS) ≥ 400 mm [3] and were compare with the remaining patients. Predictors of severe TAC were assessed through stepwise multivariable logistic regression analysis.

RESULTS

The patients with TACS ≥ 400 had a higher mean age (67.3 ± 7.1 vs. 55.7 ± 10.6; p < 0.001) with a higher frequency of diabetes mellitus (40.7% vs. 30.8%; p = 0.018), dyslipidemia (49.8% vs. 38.6%; p = 0.010), hypertension (60.8% vs. 44.7%; p < 0.001), opium addiction (18.2% vs. 11.2%; p = 0.023), peripheral vascular disease (PVD) (7.7% vs. 2.3%; p = 0.005) as compared with TACS < 400. The multiple determinants of TAC were PVD (OR = 2.86) followed by opium addiction, diabetes and age.

CONCLUSIONS

Thoracic CT scan prior to cardiac surgery for patients with older age, diabetes, opium addiction and PVD is recommended. Our study could serve as a foundation for future research endeavors aimed at establishing a risk score for TAC.

Clinical efficacy and patients' perception of virtual reality during wound care in adults: A systematic review with meta-analysis of randomised clinical trials

This study was aimed to review Virtual Reality's (VR) impact on pain, anxiety, opioid usage, physiological and behavioural responses, and patients' experience during wound care (WC) in adults. We searched multiple databases (Embase, Medline ALL, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, CINAHL, Scopus and Google Scholar) from inception until January 27th, 2023. Included studies compared VR alone or as an adjunct to standard WC with standard WC or other distraction methods, in adults with burn or non-burn-related wounds. The risk of bias was assessed using the revised Cochrane risk-of-bias tool for randomised parallel-group and crossover trials. The review followed PRISMA guidelines for reporting. Fourteen studies were eligible for inclusion. The meta-analysis was limited to studies comprising solely of adult participants. VR reduced pain intensity compared to standard WC in all study designs. Despite not being included in the meta-analysis due to reasons such as mixed population or lack of sufficient statistical data, other studies showed significant pain reduction using VR. Additionally, VR improved patients' experience of WC. No clear effect was found on other outcomes including anxiety, opioid usage and physiological and behavioural responses. VR shows promise in reducing acute pain and enhancing patients' experience of WC. The observed variations in the effects of VR at group and individual levels indicate the need for a personalised treatment plan by selecting the right VR for the right patient given at the right time.

Opioid-Based vs Opioid-Free Anesthesia in Breast Cancer Surgery

Introduction

Breast cancer is the most widely recognized malignant growth in ladies in India and accounts for 14% of all tumors in women. Modified radical mastectomy (MRM) is a surgery done for breast cancer. It leads to about 30% chances of postoperative nausea and vomiting (PONV) and 40% pain in the immediate postoperative period.

Objectives

Changes in blood pressure after intubation, waiting time for postoperative pain medication, and possibility of adverse effects.

Methodology

After the approval of ethical committee, the study was conducted in the procedure and possible complications associated with the procedure were explained to patients. Written informed consent was obtained from each patient.

Result and Conclusion

We conclude that opioid-free anesthesia is "more effective in reducing the incidence of postoperative nausea and vomiting, produces stable hemodynamics, and reduces incidence of side effects when compared with opioid-based general anesthesia in patients undergoing breast cancer surgeries."

Immunosuppression by opioids: Mechanisms of action on innate and adaptive immunity

Opioids are excellent analgesics for the clinical treatment of various types of acute and chronic pain, particularly cancer-related pain. Nevertheless, it is well known that opioids have some nasty side effects, including immunosuppression, which is commonly overlooked. As a result, the incidence of opportunistic bacterial and viral infections increases in patients with long-term opioid use. Nowadays, there are no effective medications to alleviate opioid-induced immunosuppression. Understanding the underlying molecular mechanism of opioids in immunosuppression can enable researchers to devise effective therapeutic interventions. This review comprehensively summarized the exogenous opioids-induced immunosuppressive effects and their underlying mechanisms, the regulatory roles of endogenous opioids on the immune system, the potential link between opioid immunosuppressive effect and the function of the central nervous system (CNS), and the future perspectives in this field.

THE EFFECT OF REGIONAL VS. GENERAL ANESTHESIA ON THE IMMUNE RESPONSE IN BREAST CANCER SURGERY: A NARRATIVE REVIEW OF THE LITERATURE

For breast cancer patients, surgery remains the cornerstone in treatment. Perioperative and postoperative period is associated with impaired immune function that can have profound implications for cancer patients in terms of tumor recurrence and metastases. The three main factors include surgery and related neuroendocrine stress response, anesthetic drugs, including opioid analgesics and postoperative pain. The most investigated immune cells are natural killer (NK) cells that are affected by both anesthesia and surgery. It has been demonstrated that ketamine, thiopental, volatile anesthetics, fentanyl and morphine, but not propofol, remifentanil or tramadol reduce the number of circulating NK cells and depress their toxicity. The level of NK cells' cytotoxicity is inversely proportional to the stage and spread of cancer. Regional anesthesia and its potential beneficial effects on the perioperative immune response and long-term outcome after surgery has been investigated as an alternative to general anesthesia in patients undergoing breast cancer surgery. In this paper, we present a review of literature aimed to assess the impact of regional anesthesia techniques on the immune response in patients undergoing breast cancer surgery and how it compares to general anesthesia.

The µ-Opioid Receptor in Cancer and Its Role in Perineural Invasion: A Short Review and New Evidence

Cancer is a significant public health problem worldwide. While there has been a steady decrease in the cancer death rate over the last two decades, the number of survivors has increased and, thus, cancer-related sequela. Pain affects the life of patients with cancer and survivors. Prescription opioids continue as the analgesic of choice to treat moderate-to-severe cancer-related pain. There has been controversy on whether opioids impact cancer progression by acting on cancer cells or the tumor microenvironment. The μ-opioid receptor is the site of action of prescription opioids. This receptor can participate in an important mechanism of cancer spread, such as perineural invasion. In this review, current evidence on the role of the μ-opioid receptor in cancer growth is summarized and preliminary evidence about its effect on the cross-talk between sensory neurons and malignant cells is provided.

Preoperative opiate use leads to increased postoperative opiate use and readmissions after anterior cervical discectomy and fusion

BACKGROUND

Determine effects of pre-operative opiate use on anterior cervical discectomy and fusion (ACDF) surgery outcomes.

METHODS

The study design was a single center retrospective cohort study. Patient records were reviewed from 2013 and 2018 for elective 1 to 2 level ACDF surgeries. Patients were classified as: opiate naive (ON: no history of opiate) use, acute opiate (AO: <6 months preoperatively) use, and chronic opiate (CO: 6-12 months preoperatively) use based on prescription history before surgery. Opiate use was quantified by milligram morphine equivalents (MME) at 6-12 months preop, 0-6 months preop, 0-6 months postop, and 6-12 months postop. Charts were reviewed for American Society of Anesthesiologists (ASA) physical status classification and smoking history.

RESULTS

Readmission rates were 9.8% for ON, 9.1% for AO, and 30% for CO (P value <0.05). Average opiate use measured in MME 6-12 months post-surgery was 5.76 for ON, 18.44 for AO, and 39.92 for CO (P value <0.05). Readmission rate between nonsmokers, former smokers, and active smokers was 4.4%, 0%, and 10.8% (P value <0.05) at 30-90 days post-surgery, and 1.1%, 14.5%, and 2.5% (P value <0.05) in the 91 days to 1-year post-surgery.

CONCLUSIONS

There is statistically significant relationship between CO and higher readmission rates after ACDF. Preoperative opiate use is also associated with increased opiate use 6-12 months after surgery. Smoking history is also associated with increased readmission rates.

Impact of preoperative opioid use on patient-reported outcomes following primary total knee arthroplasty

PURPOSE

The previous literature suggests that 25-30% of patients who undergo total knee arthroplasty (TKA) are using opioids prior to their surgery. This study aims to investigate the effect of preoperative opioid use on clinical outcomes and patient-reported outcome measures (PROMs) following TKA.

METHODS

We retrospectively reviewed 329 patients who underwent primary TKA from 2019 to 2020, answered the preoperative opioid survey, and had available PROMs. Patients were stratified into two groups based on whether they were taking opioids preoperatively or not: 26 patients with preoperative opioid use (8%) and 303 patients without preoperative opioid use (92%) were identified. Demographics, clinical data, and PROMs [Forgotten Joint Score (FJS-12), Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR), and Veterans RAND-12 Physical and Mental components (VR-12 PCS and MCS)] were collected. Demographic differences were assessed with Chi-square and independent sample t-tests. Outcomes were compared using multilinear regression analysis, controlling for demographic differences.

RESULTS

Preoperative opioid users had a significantly longer length-of-stay (2.74 vs. 2.10; p = 0.010), surgical time (124.65 vs. 105.69; p < 0.001), and were more likely to be African-American (38.5 vs. 14.2%; p = 0.010) compared to preoperative opioid-naive patients. Postoperative FJS-12 did not statistically differ between the two groups. While preoperative KOOS, JR scores were significantly lower for preoperative opioid users (41.10 vs. 46.63; p = 0.043), they did not significantly differ postoperatively. Preoperative VR-12 PCS did not statistically differ between the groups; however, both 3-month (33.87 vs. 38.41; p = 0.049) and 1-year (36.01 vs. 44.73; p = 0.043) scores were significantly lower for preoperative opioid users. Preoperative VR-12 MCS was significantly lower for preoperative opioid users (46.06 vs. 51.06; p = 0.049), though not statistically different postoperatively.

CONCLUSION

At 8%, our study population had a lower percentage of opioid users than previously reported in the literature. Preoperative opioid users had longer operative times and length of stay compared to preoperatively opioid-naive patients. While both cohorts achieved similar clinical benefits following TKA, preoperative opioid users reported lower postoperative scores with respect to VR-12 PCS scores.

LEVEL III EVIDENCE

Retrospective Cohort.

Reducing Pain in Experimental Models of Intestinal Inflammation Affects the Immune Response

The incidence of inflammatory bowel disease with its two main manifestations, colitis ulcerosa and Crohn's disease, is rising globally year after year. There is still a tremendous need to study the underlying pathomechanisms and a well-established tool in order to better understand the disease are colitis models in rodents. Since the concept of the 3Rs was proposed by Russell and Burch, this would include pain medication in animal models of intestinal inflammation as a reduction of suffering. This review argues against pain medication because the administration of pain medication in its current form has an impact on the inflammatory process and the immune response, thus falsifying the results and the reproducibility and therefore leading to misconceptions.

Grade IV Sacral Sore Treated with an Ointment Rich in PUFAs, Ceramides, and Antimicrobial Peptides

This report presents the case of a 57-year-old male patient with a history of hypertension, obesity, dyslipidemia, and coronary disease that after a prolonged postcoronary surgery hospitalization developed a sacral butterfly-shaped sore, with asymmetric involvement of the base of both buttocks, grade III on the left and grade IV on the right sides. The lesion was very painful and had a negative impact on the patient's sleep and mood. Following the initial surgical debridement and treatment with collagenase ointment, the wound showed delayed healing, an increase in necrotic tissue, and purulent discharge, requiring a second surgical debridement that revealed a deeper involvement of the wound. After a month with poor therapeutic response, it was decided to change the treatment to the application of gauzes embedded in an ointment rich in polyunsaturated fatty acids (PUFAs), ceramides, and antimicrobial peptides, Curefini® ointment. After 30 days of treatment, a 50% reduction of the initial wound diameter was obtained with a positive impact on the patient's quality of life, together with a reduction of incidental and spontaneous local pain resulting in better night rest and a return of appetite and strength. During the treatment course, the patient did not suffer any local or systemic infection in connection with the wound. After one month, the patient could discontinue the use of opioid analgesics. A 95% closure of the lesion was achieved in 45 days. This case highlights the therapeutic efficacy of the treatment of cavitated wounds with a product based on natural ingredients that helps reduce pain and promotes granulation and reepithelialization.

Papaver Plants: Current Insights on Phytochemical and Nutritional Composition Along with Biotechnological Applications

The genus Papaver is highly esteemed in the pharmacy industry, in the culinary field, and as ornamental plants. These plants are also valued in traditional medicine. Among all Papaver species, Papaver somniferum L. (opium poppy) is the most important species in supplying phytochemicals for the formulation of drugs, mainly alkaloids like morphine, codeine, rhoeadine, thebaine, and papaverine. In addition, Papaver plants present other types of phytochemicals, which altogether are responsible for its biological activities. Therefore, this review covers the phytochemical composition of Papaver plants, including alkaloids, phenolic compounds, and essential oils. The traditional uses are reviewed along with their pharmacological activities. Moreover, safety aspects are reported to provide a deep overview of the pharmacology potential of this genus. An updated search was carried out in databases such as Google Scholar, ScienceDirect, and PubMed to retrieve the information. Overall, this genus is a rich source of alkaloids of different types and also contains interesting phenolic compounds, such as anthocyanins, flavonols, and the characteristic indole derivatives nudicaulins. Among other pharmacological properties, numerous preclinical studies have been published about the analgesic, anticancer, antimicrobial, antioxidant, and antidiabetic activities of Papaver plants. Although it highlights the significant impact of this genus for the treatment of a variety of diseases and conditions, as a future prospect, characterization works accompanying preclinical studies are required along with clinical and toxicology studies to establish a correlation between the scientific and traditional knowledge.

Opioids Regulate the Immune System: Focusing on Macrophages and Their Organelles

Opioids are the most widely used analgesics and therefore have often been the focus of pharmacological research. Macrophages are the most plastic cells in the hematopoietic system. They show great functional diversity in various organism tissues and are an important consideration for the study of phagocytosis, cellular immunity, and molecular immunology. The expression of opioid receptors in macrophages indicates that opioid drugs act on macrophages and regulate their functions. This article reviewed the collection of research on effects of opioids on macrophage function. Studies show that opioids, both endogenous and exogenous, can affect the function of macrophages, effecting their proliferation, chemotaxis, transport, phagocytosis, expression of cytokines and chemokine receptors, synthesis and secretion of cytokines, polarization, and apoptosis. Many of these effects are closely associated with mitochondrial function and functions of other organelles in macrophages. Therefore, in depth research into effects of opioids on macrophage organelles may lead to some interesting new discoveries. In view of the important role of macrophages in HIV infection and tumor progression, this review also discusses effects of opioids on macrophages in these two pathological conditions.

Wound healing: potential therapeutic options

This review highlights the range of therapeutic options available to clinicians treating difficult-to-heal wounds. While certain treatments are established in daily clinical practice, most therapeutic interventions lack robust and rigorous data regarding their efficacy, which would help to determine when, and for whom, they should be used. The purpose of this review is to give a broad overview of the available interventions, with a brief summary of the evidence base for each intervention.

Assessment of the structural and functional characteristics of human mesenchymal stem cells associated with a prolonged exposure of morphine

The discovery of the expression of opioid receptors in the skin and their role in orchestrating the process of tissue repair gave rise to questions regarding the potential effects of clinical morphine treatment in wound healing. Although short term treatment was reported to improve tissue regeneration, in vivo chronic administration was associated to an impairment of the physiological healing process and systemic fibrosis. Human mesenchymal stem cells (hMSCs) play a fundamental role in tissue regeneration. In this regard, acute morphine exposition was recently reported to impact negatively on the functional characteristics of hMSCs, but little is currently known about its long-term effects. To determine how a prolonged treatment could impair their functional characteristics, we exposed hMSCs to increasing morphine concentrations respectively for nine and eighteen days, evaluating in particular the fibrogenic potential exerted by the long-term exposition. Our results showed a time dependent cell viability decline, and conditions compatible with a cellular senescent state. Ultrastructural and protein expression analysis were indicative of increased autophagy, suggesting a relation to a detoxification activity. In addition, the enhanced transcription observed for the genes involved in the synthesis and regulation of type I collagen suggested the possibility that a prolonged morphine treatment might exert its fibrotic potential risk, even involving the hMSCs.

Dose-Dependent Early Postoperative Opioid Use Is Associated with Periprosthetic Joint Infection and Other Complications in Primary TJA

BACKGROUND

Opioids are commonly prescribed for postoperative pain following total joint arthroplasty. Despite widespread use, few studies have examined the dose-dependent effect of perioperative opioid use on postoperative complications following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Therefore, we examined the dose-dependent relationship between opioid use and postoperative complications following primary THA and TKA.

METHODS

We queried the Premier Healthcare Database to identify adult patients who underwent primary elective THA or TKA from 2004 to 2014, and quantified opioid consumption within the first 3 postoperative days. Opioid consumption was standardized to morphine milligram equivalents (MMEs). Patients were divided into quintiles on the basis of MME exposure: <54, 54 to 82, 83 to 116, 117 to 172, and >172 MMEs. Primary outcomes included postoperative periprosthetic joint infection, pulmonary embolism, deep venous thrombosis, and pulmonary complications. Secondary outcomes included wound infection, wound dehiscence, and readmission within 30 and 90 days postoperatively. Univariate and multivariate analyses were performed to compare differences between groups and to account for confounders.

RESULTS

A total of 1,525,985 patients were identified. The mean age was 65.7 ± 10.8 years, 598,320 patients (39.2%) were male, and 1,174,314 patients (77.0%) were Caucasian. On multiple logistic regression analysis, increasing MME exposure was associated with a dose-dependent increased risk of postoperative complications. Compared with patients receiving <54 MMEs, exposure to >172 MMEs was associated with greater odds of periprosthetic joint infection (adjusted odds ratio [aOR], 1.37; 95% confidence interval [CI], 1.33 to 1.42), deep venous thromboembolism (aOR, 1.34; 95% CI, 1.30 to 1.38), pulmonary embolism (aOR, 1.29; 95% CI, 1.25 to 1.34), and pulmonary complications (aOR, 1.06; 95% CI, 1.05 to 1.08). Exposure to >172 MMEs was associated with increased risk of wound infection (aOR, 1.37; 95% CI, 1.33 to 1.41), wound dehiscence (aOR, 1.24; 95% CI, 1.19 to 1.31), and readmission within 30 (aOR, 1.21; 95% CI, 1.20 to 1.22) and 90 days (aOR, 1.20; 95% CI, 1.19 to 1.21).

CONCLUSIONS

Increasing opioid use within the early postoperative period following THA or TKA was associated with a dose-dependent increased risk of periprosthetic joint infection and venous thromboembolic events.

LEVEL OF EVIDENCE

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

Keratin Scaffolds Containing Casomorphin Stimulate Macrophage Infiltration and Accelerate Full-Thickness Cutaneous Wound Healing in Diabetic Mice

Impaired wound healing is a major medical challenge, especially in diabetics. Over the centuries, the main goal of tissue engineering and regenerative medicine has been to invent biomaterials that accelerate the wound healing process. In this context, keratin-derived biomaterial is a promising candidate due to its biocompatibility and biodegradability. In this study, we evaluated an insoluble fraction of keratin containing casomorphin as a wound dressing in a full-thickness surgical skin wound model in mice (n = 20) with iatrogenically induced diabetes. Casomorphin, an opioid peptide with analgesic properties, was incorporated into keratin and shown to be slowly released from the dressing. An in vitro study showed that keratin-casomorphin dressing is biocompatible, non-toxic, and supports cell growth. In vivo experiments demonstrated that keratin-casomorphin dressing significantly (p < 0.05) accelerates the whole process of skin wound healing to the its final stage. Wounds covered with keratin-casomorphin dressing underwent reepithelization faster, ending up with a thicker epidermis than control wounds, as confirmed by histopathological and immunohistochemical examinations. This investigated dressing stimulated macrophages infiltration, which favors tissue remodeling and regeneration, unlike in the control wounds in which neutrophils predominated. Additionally, in dressed wounds, the number of microhemorrhages was significantly decreased (p < 0.05) as compared with control wounds. The dressing was naturally incorporated into regenerating tissue during the wound healing process. Applied keratin dressing favored reconstruction of more regular skin structure and assured better cosmetic outcome in terms of scar formation and appearance. Our results have shown that insoluble keratin wound dressing containing casomorphin supports skin wound healing in diabetic mice.

The Incidence of New Persistent Opioid Use Following Cardiac Surgery via Sternotomy

BACKGROUND

In recent years, increased attention has turned toward the risk of chronic opioid use after surgery. In this nationwide cohort study, we examined the rate of new persistent opioid use after cardiac surgery by sternotomy.

METHODS

All opioid-naive patients undergoing heart surgery by sternotomy from 2005 to 2018 in Iceland were included in the study. Naivety was defined as not filling an opioid prescription within 6 months before surgery. Persistent opioid use was defined as filling at least 1 opioid prescription during the first 90 days after surgery and another 90 to 180 days after the operation. In addition to estimating the incidence of new persistent opioid use, differences in patient characteristics, survival, and readmission rates were compared between the group with and without new persistent opioid use.

RESULTS

Of 1227 patients who underwent cardiac surgery by sternotomy during the study period, 925 were included in the study. Of those, 4.6% developed new persistent opioid use. When only patients who filled an opioid prescription after surgery were included, 10.1% developed new persistent opioid use. Chronic obstructive pulmonary disease, preoperative use of nonsteroidal anti-inflammatory drugs, gabapentinoids, and nitrates were associated with increased risk for new persistent opioid use. Patients with new persistent opioid use did not have higher rates of readmission nor all-cause mortality.

CONCLUSIONS

The rate of new persistent opioid use after cardiac surgery was 4.6%. Future steps should identify strategies to minimize the development of new persistent opioid use.

Macrophages in dermatology: pathogenic roles and targeted therapeutics

The field of macrophage biology is rapidly growing. Recent studies have shifted focus from classic wound healing roles to newly identified roles in dermatologic pathology. These studies have identified pathogenic roles of macrophages in relatively common conditions, such as psoriasis, skin cancer, and cutaneous T-cell lymphoma. Selective depletion of these cells or their associated cytokines leads to improved clinical outcome. Herein, we review recent animal and human studies that have elucidated novel pathogenic roles of macrophages in conditions frequently encountered by dermatologists and discuss clinically relevant macrophage-targeted therapies.

Opioid-Mediated HIV-1 Immunopathogenesis

Despite the ability of combination antiretroviral therapy to dramatically suppress viremia, the brain continues to be a reservoir of HIV-1 low-level replication. Adding further complexity to this is the comorbidity of drug abuse with HIV-1 associated neurocognitive disorders and neuroHIV. Among several abused drugs, the use of opiates is highly prevalent in HIV-1 infected individuals, both as an abused drug as well as for pain management. Opioids and their receptors have attained notable attention owing to their ability to modulate immune functions, in turn, impacting disease progression. Various cell culture, animal and human studies have implicated the role of opioids and their receptors in modulating viral replication and virus-mediated pathology both positively and negatively. Further, the combinatorial effects of HIV-1/HIV-1 proteins and morphine have demonstrated activation of inflammatory signaling in the host system. Herein, we summarized the current knowledge on the role of opioids on peripheral immunopathogenesis, viral immunopathogenesis, epigenetic profiles of the host and viral genome, neuropathogenesis of SIV/SHIV-infected non-human primates, blood-brain-barrier, HIV-1 viral latency, and viral rebound. Overall, this review provides recent insights into the role of opioids in HIV-1 immunopathogenesis. Graphical abstract.

Effect of Opioid Use on Immune Activation and HIV Persistence on ART

While there is an emerging consensus that engagement of the Mu opioid receptor by opioids may modulate various stages the HIV life cycle (e.g.: increasing cell susceptibility to infection, promoting viral transcription, and depressing immune responses to virally-infected cells), the overall effect on latency and viral reservoirs remains unclear. Importantly, the hypothesis that the increase in immune activation observed in chronic opioid users by direct or indirect mechanisms (i.e., microbial translocation) would lead to a larger HIV reservoir after ART-suppression has not been supported to date. The potential for a subsequent decrease in reservoirs after ART-suppression has been postulated and is supported by early reports of opioid users having lower latent HIV burden. Here, we review experimental data supporting the link between opioid use and HIV modulation, as well as the scientific premise for expecting differential changes in immune activation and HIV reservoir between different medications for opioid use disorder. A better understanding of potential changes in HIV reservoirs relative to the engagement of the Mu opioid receptor and ART-mediated immune reconstitution will help guide future cure-directed studies in persons living with HIV and opioid use disorder. Graphical Abstract Review. HIV replication, immune activation and dysbiosis: opioids may affect immune reconstitution outcomes despite viral suppression.

The Endogenous Opioid System in Schizophrenia and Treatment Resistant Schizophrenia: Increased Plasma Endomorphin 2, and κ and μ Opioid Receptors Are Associated with Interleukin-6

BACKGROUND

activation of the immune-inflammatory response system (IRS) and the compensatory immune-regulatory system (CIRS) plays a key role in schizophrenia (SCZ) and treatment resistant SCZ. There are only a few data on immune and endogenous opioid system (EOS) interactions in SCZ and treatment resistant SCZ.

METHODS

we examined serum β-endorphin, endomorphin-2 (EM2), mu-opioid (MOR) and kappa-opioid (KOR) receptors, and interleukin (IL)-6 and IL-10 in 60 non responders to treatment (NRTT), 55 partial RTT (PRTT) and 43 normal controls.

RESULTS

serum EM2, KOR, MOR, IL-6 and IL-10 were significantly increased in SCZ as compared with controls. β-endorphin, EM2, MOR and IL-6 were significantly higher in NRTT than in PRTT. There were significant correlations between IL-6, on the one hand, and β-endorphin, EM2, KOR, and MOR, on the other, while IL-10 was significantly correlated with MOR only. A large part of the variance in negative symptoms, psychosis, hostility, excitation, mannerism, psychomotor retardation and formal thought disorders was explained by the combined effects of EM2 and MOR with or without IL-6 while increased KOR was significantly associated with all symptom dimensions. Increased MOR, KOR, EM2 and IL-6 were also associated with neurocognitive impairments including in episodic, semantic and working memory and executive functions.

CONCLUSION

the EOS contributes to SCZ symptomatology, neurocognitive impairments and a non-response to treatment. In SCZ, EOS peptides/receptors may exert CIRS functions, whereas increased KOR levels may contribute to the pathophysiology of SCZ and EM2 and KOR to a non-response to treatment.

Pain assessment following burn injury in Australia and New Zealand: Variation in practice and its association on in-hospital outcomes

BACKGROUND

Pain is common following burn injury. Pain assessments are required to ensure appropriate pain management is provided. This study aimed to describe the prevalence and potential variation in practice of validated and documented pain assessment following burn injury in Australian and New Zealand burn units, identify clinical characteristics of patients who receive a pain assessment, and explore the associations between receiving a pain assessment and in-hospital outcomes.

METHODS

Burns Registry of Australia and New Zealand (BRANZ) admissions data were extracted. Responses to the pain assessment field were presented by contributing burns unit using frequencies and percentages. Demographic, injury severity and event, and in-hospital outcomes data were assessed.

RESULTS

There were 3009 admissions over the study period; 2481 of these received an assessment. The rate of pain assessment varied considerably between units. Women and adult patients more commonly received a pain assessment. Receiving a pain assessment was associated with a 53% adjusted increase in LOS.

CONCLUSIONS

There are differences in the profile of patients who receive a pain assessment after burn injury. The findings of this study will be reported back to designated burns units to improve pain assessment rates and patient care.

Toll-Like Receptor 4 (TLR4)/Opioid Receptor Pathway Crosstalk and Impact on Opioid Analgesia, Immune Function, and Gastrointestinal Motility

Toll-like receptor 4 (TLR4) recognizes exogenous pathogen-associated molecular patterns (PAMPs) and endogenous danger-associated molecular patterns (DAMPs) and initiates the innate immune response. Opioid receptors (μ, δ, and κ) activate inhibitory G-proteins and relieve pain. This review summarizes the following types of TLR4/opioid receptor pathway crosstalk: (a) Opioid receptor agonists non-stereoselectively activate the TLR4 signaling pathway in the central nervous system (CNS), in the absence of lipopolysaccharide (LPS). Opioids bind to TLR4, in a manner parallel to LPS, activating TLR4 signaling, which leads to nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) expression and the production of the pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6. (b) Opioid receptor agonists inhibit the LPS-induced TLR4 signaling pathway in peripheral immune cells. Opioids operate as pro-inflammatory cytokines, resulting in neuroinflammation in the CNS, but they mediate immunosuppressive effects in the peripheral immune system. It is apparent that TLR4/opioid receptor pathway crosstalk varies dependent on the cell type and activating stimulus. (c) Both the TLR4 and opioid receptor pathways activate the mitogen-activated protein kinase (MAPK) pathway. This crosstalk is located downstream of the TLR4 and opioid receptor signaling pathways. Furthermore, the classic opioid receptor can also produce pro-inflammatory effects in the CNS via MAPK signaling and induce neuroinflammation. (d) Opioid receptor agonists induce the production of high mobility group box 1 (HMGB1), an endogenous TLR4 agonist, supporting intercellular (neuron-to-glia or glia-to-neuron) interactions. This review also summarizes the potential effects of TLR4/opioid receptor pathway crosstalk on opioid analgesia, immune function, and gastrointestinal motility. Opioids non-stereoselectively activate the TLR4 pathway, and together with the subsequent release of pro-inflammatory cytokines such as IL-1 by glia, this TLR4 signaling initiates the central immune signaling response and modifies opioid pharmacodynamics. The DAMP HMGB1 is associated with the development of neuropathic pain. To explain morphine-induced persistent sensitization, a positive feedback loop has been proposed; this involves an initial morphine-induced amplified release of IL-1β and a subsequent exacerbated release of DAMPs, which increases the activation of TLR4 and the purinergic receptor P2X7R. Opioid receptor (μ, δ, and κ) agonists are involved in many aspects of immunosuppression. The intracellular TLR4/opioid receptor signaling pathway crosstalk induces the formation of the β-arrestin-2/TNF receptor-associated factor 6 (TRAF6) complex, which contributes to morphine-induced inhibition of LPS-induced TNF-α secretion in mast cells. A possible molecular mechanism is that the TLR4 pathway initially triggers the formation of the β-arrestin-2/TRAF6 complex, which is amplified by opioid receptor signaling, suggesting that β-arrestin-2 acts as a functional component of the TLR4 pathway.

Preoperative opioid use is associated with increased risk of postoperative complications within a colorectal-enhanced recovery protocol

BACKGROUND

As the opioid epidemic escalates, preoperative opioid use has become increasingly common. Recent studies associated preoperative opioid use with postoperative morbidity. However, limited study of its impact on patients within enhanced recovery protocols (ERP) exists. We assessed the impact of preoperative opioid use on postoperative complications among colorectal surgery patients within an ERP, hypothesizing that opioid-exposed patients would be at increased risk of complications.

METHODS

Elective colorectal cases from August 2013 to June 2017 were reviewed in a retrospective cohort study comparing preoperative opioid-exposed patients to opioid-naïve patients. Postoperative complications were defined as a composite of complications captured by the American College of Surgeons National Surgical Quality Improvement Program. Logistic regression identified risk factors for postoperative complications.

RESULTS

707 patients were identified, including 232 (32.8%) opioid-exposed patients. Opioid-exposed patients were younger (57.9 vs 61.9 years; p < 0.01) and more likely to smoke (27.6 vs 17.1%; p < 0.01). Laparoscopic procedures were less common among opioid-exposed patients (44.8 vs 58.1%; p < 0.01). Median morphine equivalents received were higher in opioid-exposed patients (65.0 vs 20.1 mg; p < 0.01), but compliance to ERP elements was otherwise equivalent. Postoperative complications were higher among opioid-exposed patients (28.5 vs 15.0%; p < 0.01), as was median length of stay (4.0 vs 3.0 days; p < 0.01). Logistic regression identified multiple patient- and procedure-related factors independently associated with postoperative complications, including preoperative opioid use (p = 0.001).

CONCLUSION

Preoperative opioid use is associated with increased risk of postoperative complications in elective colorectal surgery patients within an ERP. These results highlight the negative impact of opioid use, suggesting an opportunity to further reduce the risk of surgical complications through ERP expansion to include preoperative mitigation strategies for opioid-exposed patients.

Characterizing the risk and outcome profiles of lumbar fusion procedures in patients with opioid use disorders: a step toward improving enhanced recovery protocols for a unique patient population

OBJECTIVEThe authors set out to conduct the first national-level study assessing the risks and outcomes for different lumbar fusion procedures in patients with opioid use disorders (OUDs) to help guide the future development of targeted enhanced recovery after surgery (ERAS) protocols for this unique population.METHODSData for patients with or without OUDs who underwent an anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), or lateral transverse lumbar interbody fusion (LLIF) for lumbar disc degeneration (LDD) were collected from the 2013-2014 National (Nationwide) Inpatient Sample database. Multivariable logistic regression was implemented to analyze how OUD status impacted in-hospital complications, length of hospital stay, discharge disposition, and total charges by procedure type.RESULTSA total of 139,995 patients with LDD were identified, with 1280 patients (0.91%) also having a concurrent OUD diagnosis. Overall complication rates were higher in OUD patients (48.44% vs 31.01%, p < 0.0001). OUD patients had higher odds of pulmonary (p = 0.0006), infectious (p < 0.0001), and hematological (p = 0.0009) complications. Multivariate regression modeling of outcomes by procedure type showed that after ALIF, OUD patients had higher odds of nonhome discharge (p = 0.0007), extended hospitalization (p = 0.0002), and greater total charges (p = 0.0054). This analysis also revealed that OUD patients faced higher odds of complication (p = 0.0149 and p = 0.0471), extended hospitalization (p = 0.0439 and p = 0.0001), and higher total charges (p < 0.0001 and p < 0.0001) after PLIF and LLIF procedures, respectively.CONCLUSIONSObtaining a better understanding of the risks and outcomes that OUD patients face perioperatively is a necessary step toward developing more effective ERAS protocols for this vulnerable population. This study, which sought to characterize the outcome profiles for lumbar fusion procedures in OUD patients on a national level, found that this population tended to experience increased odds of complications, extended hospitalization, nonhome discharge, and higher total costs. Results from this study warrant future prospective studies to better the understanding of these associations and to further the development of better ERAS programs that may improve patient care and reduce cost burden.

Preoperative Narcotic Use, Impaired Ambulation Status, and Increased Intraoperative Blood Loss Are Independent Risk Factors for Complications Following Posterior Cervical Laminectomy and Fusion Surgery

OBJECTIVE

This retrospective cohort study seeks to identify risk factors associated with complications following posterior cervical laminectomy and fusion (PCLF) surgery.

METHODS

Adults undergoing PCLF from 2012 through 2018 at a single center were identified. Demographic and radiographic data, surgical characteristics, and complication rates were compared. Multivariate logistic regression models identified independent predictors of complications following surgery.

RESULTS

A total of 196 patients met the inclusion criteria and were included in the study. The medical, surgical, and overall complication rates were 10.2%, 23.0%, and 29.1% respectively. Risk factors associated with medical complications in multivariate analysis included impaired ambulation status (odds ratio [OR], 2.27; p=0.02) and estimated blood loss over 500 mL (OR, 3.67; p=0.02). Multivariate analysis revealed preoperative narcotic use (OR, 2.43; p=0.02) and operative time (OR, 1.005; p=0.03) as risk factors for surgical complication, whereas antidepressant use was a protective factor (OR, 0.21; p=0.01). Overall complication was associated with preoperative narcotic use (OR, 1.97; p=0.04) and higher intraoperative blood loss (OR, 1.0007; p=0.03).

CONCLUSION

Preoperative narcotic use and estimated blood loss predicted the incidence of complications following PCLF for CSM. Ambulation status was a significant predictor of the development of a medical complication specifically. These results may help surgeons in counseling patients who may be at increased risk of complication following surgery.

Perioperative outcomes among chronic opioid users who receive lobectomy for non-small cell lung cancer

OBJECTIVE

We sought to identify whether chronic opioid users are at increased risk for complications or hospital readmission following lobectomy for non-small cell lung cancer.

METHODS

The National Cancer Institute Surveillance, Epidemiology, and End Results-Medicare database was queried to identify patients older than age 65 years who received a lobectomy for non-small cell lung cancer. Chronic opioid users were identified through Medicare Part D records and were defined as those with >120 cumulative days of opioid supply for the year before surgery. A systematic 1:2 propensity matching was performed among chronic opioid users.

RESULTS

Six thousand four hundred thirty-seven patients were identified, among whom 3627 (56%) were opioid naïve, 1866 (29%) were intermittent opioid users, and 944 (15%) were chronic opioid users. After propensity matching, 30-day mortality and 90-day mortality were nearly 2-fold higher among chronic opioid users compared with nonchronic users. In addition, length of stay and hospital charges were increased among chronic opioid users (median, 6 vs 7 days and mean increase, $12,526, respectively). Multivariable analysis revealed that intermittent opioid users and chronic opioid users were associated with an increased risk of 90-day hospital readmission compared with opioid-naïve patients (odds ratio, 1.35; 95% confidence interval, 1.07-1.71 and odds ratio, 1.72; 95% confidence interval, 1.40-2.12, respectively), predominantly burdened by infectious, renal, and pulmonary causes.

CONCLUSIONS

Patients who chronically use opioids before lobectomy represent high-risk patients. The risk of 30- and 90-day mortality, length of stay, hospital charges, and 90-day readmission after lobectomy among chronic opioid users are substantially elevated.

Increasing the Risk of Stroke by Opium Addiction

INTRODUCTION

Stroke is among the leading causes of mortality and morbidity in the world. Besides the identified risk factor, Ischemic stroke evidence show drug use develops or exacerbates the atherosclerotic process. The current study aimed at comparing cerebrovascular ultrasounds' changes in addicted and nonaddicted people who developed ischemic stroke.

METHODS

In the current cross-sectional study, a total of 133 patients with ischemic stroke who were admitted to Vali-Asr hospital from June 2016 to April 2017 were enrolled. For obtaining the quantitative data, t test or Mann-Whitney test was employed to compare the addict or no-addict groups, as well as, categorical data testing was performed using chi-square test. Also, the multiple logistic regression was used for identifying the factors and the significance level was set at 5%.

RESULTS

The current study was performed on 133 patients, among them 41 patients (30.8%) were opium addicted, and 92 patients (69.2%) were nonaddict. The mean [IQR] number of atherosclerotic plaques were significantly higher in opium addicted group in comparison with the nonaddicted group (3.0 [1.0-4.0] versus 1.5 [0.0-3.0], P = .008). The possibility of increasing the number of plaques in addicted patients was 1.42 times higher than the nonaddicted patients (odds ratio (95% confidence interval): 1.42 (1.11-1.81), P = .005).

CONCLUSION

The findings demonstrated a significant difference in the vessel stenosis pattern between the addict and nonaddict ischemic stroke groups. To investigate the possible effects of opium use and its associated parameters, ie, dosage, duration of use, and the way of opium use on ischemic stroke, further studies are required.

Chronic preoperative opioid use is a risk factor for increased complications, resource use, and costs after cervical fusion

BACKGROUND CONTEXT

As health-care transitions to value-based models, there has been an increased focus on patient factors that can influence peri- and postoperative adverse events, resource use, and costs. Many studies have reported risk factors for systemic complications after cervical fusion, but none have studied chronic opioid therapy (COT) as a risk factor.

PURPOSE

The objective of this study was to answer the following questions from a large cohort of patients who underwent primary cervical fusion for degenerative pathology: (1) What is the patient profile associated with preoperative COT? (2) Is preoperative COT a risk factor for 90-day systemic complications, emergency department (ED) visits, readmission, and 1-year adverse events? (3) What are the risk factors and 1-year adverse events related to long-term postoperative opioid use? (4) How much did payers reimburse for management of complications and adverse events?

STUDY DESIGN

This is a retrospective review of Humana commercial insurance data (2007-Q3 2015).

PATIENT SAMPLE

The patient sample included 29,101 patients undergoing primary cervical fusion for degenerative pathology.

METHODS

Patients and procedures of interest were included using International Classification of Diseases (ICD) coding. Patients with opioid prescriptions for >6 months before surgery were considered as having preoperative COT. Patients with continued opioid use until 1-year after surgery were considered as long-term users. Descriptive analysis of patient cohorts has been done. Multiple-variable logistic regression analyses adjusting for approach, number of levels of surgery, discharge disposition, and comorbidities were done to answer first three study questions. Reimbursement data from insurers have been reported to answer our fourth study question.

RESULTS

Of the entire cohort, 6,643 (22.8%) had preoperative COT. Preoperative COT was associated with a higher risk of 90-day wound complications (odds ratio [OR] 1.39, 95% confidence interval [CI]: 1.16-1.66), all-cause 90-day ED visits (adjusted OR 1.22, 95% CI: 1.13-1.32), and pain-related ED visits (adjusted OR 1.39, 95% CI: 1.24-1.55). Patients who had preoperative COT were more likely to receive epidural or facet joint injections within 1 year after surgery (adjusted OR 1.68, 95% CI: 1.47-1.92). These patients were also more likely to undergo a repeat cervical fusion within a year than patients who did not have preoperative COT (adjusted OR 1.21, 95% CI: 1.01-1.43). Preoperative COT had a higher likelihood of long-term use after surgery (adjusted OR 4.72, 95% CI: 4.41-5.06). Long-term opioid use after surgery was associated with a higher risk of new-onsetconstipation (adjusted OR 1.34, 95% CI: 1.22-1.48). The risk of complications and adverse events was not found to be significant in patients with <3 months of preoperative opioid use or those who stopped opioids for at least 6 weeks before surgery. The cost of additional resource use for medications, ED visits, constipation, injections, and revision fusion ranged from $623 to $27,360 per patient.

CONCLUSIONS

Preoperative opioid use among patients who underwent cervical fusion increases complication rates, postoperative opioid usage, health-care resource use, and costs. These risks may be reduced by restricting the duration of preoperative opioid use or weaning off before surgery. Better understanding and management of pain in the preoperative period with judicious use of opioids is critical to enhance outcomes after cervical fusion surgery.

Preoperative Chronic Opioid Therapy: A Risk Factor for Complications, Readmission, Continued Opioid Use and Increased Costs After One- and Two-Level Posterior Lumbar Fusion

STUDY DESIGN

Retrospective, economic analysis.

OBJECTIVE

To study patient profile associated with preoperative chronic opioid therapy (COT), and study COT as a risk factor for 90-day complications, emergency department (ED) visits, and readmission after primary one- to two-level posterior lumbar fusion (PLF) for degenerative spine disease. We also evaluated associated costs, risk factors, and adverse events related to long-term postoperative opioid use.

SUMMARY OF BACKGROUND DATA

Chronic opioid use is associated with poor outcomes and dependence after spine surgery. Risk factors, complications, readmissions, adverse events, and costs associated with COT in patients undergoing lumbar fusion are not entirely known. As providers look to reduce healthcare costs and improve outcomes, identification of modifiable risk factors is important.

METHODS

Commercial insurance data from 2007 to Q3-2015 was used to study preoperative opioid use in patients undergoing primary one- to two-level PLF. Ninety-day complications, ED visits, readmissions, 1-year adverse events, and associated costs have been described. Multiple-variable regression analyses were done to study preoperative COT patient profile and opioid use as a risk factor for complications and adverse events.

RESULTS

A total of 24,610 patients with a mean age of 65.6 ± 11.5 years were included. Five thousand five hundred (22.3%) patients had documented opioid use for more than 6 months before surgery, and 87.4% of these had continued long-term use postoperatively. On adjusted analysis, preoperative COT was found to be a risk factor for 90-day wound complications, pain diagnoses, ED visits, readmission, and continued use postoperatively. Postspinal fusion long-term opioid users had an increased utilization of epidural/facet joint injections, risk for revision fusion, and increased incidence of new onset constipation within 1 year postsurgery. The cost associated with increase resource use in these patients has been reported.

CONCLUSION

Preoperative COT is a modifiable risk factor for complications, readmission, adverse events, and increased costs after one- or two-level PLF.

LEVEL OF EVIDENCE

3.

Perioperative Immunosuppression and Risk of Cancer Progression: The Impact of Opioids on Pain Management

Opioids comprise an important group of drugs used in cancer pain pharmacotherapy. In recent years, more and more studies have emerged indicating the potentially immunosuppressive effects of opioid analgesics and their serious consequences, including the risk of cancer progression. The identification of these risks has prompted a search for other effective, and most importantly, safer methods of perioperative analgesic management. Regional analgesia techniques, which allow for a significant reduction in opioid dosing and thus diminish the risk of immunosuppression associated with these drugs, seem to offer substantial hope in this respect. A number of studies available in the literature assess the effects of regional analgesia techniques on cancer progression; however, it is often difficult to interpret their results owing to several perioperative factors (such as surgical trauma, inadequate pain and stress relief, and hypothermia) which are also attributed immunosuppressive effects and tend to be implicated in increased risk of cancer progression. Further research is needed to verify the available data on both the potential adverse effects of opioids and the possible protective effects of regional analgesia techniques on cancer patients.

Local Resiniferatoxin Induces Long-Lasting Analgesia in a Rat Model of Full Thickness Thermal Injury

Objective

Opioid-based analgesics are a major component of the lengthy pain management of burn patients, including military service members, but are problematic due to central nervous system-mediated side effects. Peripheral analgesia via targeted ablation of nociceptive nerve endings that express the transient receptor potential vanilloid channel 1 (TRPV1) may provide an improved approach. We hypothesized that local injection of the TRPV1 agonist resiniferatoxin (RTX) would produce long-lasting analgesia in a rat model of pain associated with burn injury.

Methods

Baseline sensitivities to thermal and mechanical stimuli were measured in male and female Sprague-Dawley rats. Under anesthesia, a 100 °C metal probe was placed on the right hind paw for 30 seconds, and sensitivity was reassessed 72 hours following injury. Rats received RTX (0.25 μg/100 μL; ipl) into the injured hind paw, and sensitivity was reassessed across three weeks. Tissues were collected from a separate group of rats at 24 hours and/or one week post-RTX for pathological analyses of the injured hind paw, dorsal spinal cord c-Fos, and primary afferent neuropeptide immunoreactivity.

Results

Local RTX reversed burn pain behaviors within 24 hours, which lasted through recovery at three weeks. At one week following RTX, decreased c-Fos and primary afferent neuropeptide immunoreactivities were observed in the dorsal horn, while plantar burn pathology was unaltered.

Conclusions

These results indicate that local RTX induces long-lasting analgesia in a rat model of pain associated with burn. While opioids are undesirable in trauma patients due to side effects, RTX may provide valuable long-term, nonopioid analgesia for burn patients.

Severe pain during wound care procedures: A cross-sectional study protocol

AIM

The aim of this study is to: (a) develop and evaluate a model to predict severe pain during wound care procedures (WCPs) so that high-risk patients can be targeted for specialized dressings and preventive pain control; and (b) identify biological factors associated with severe pain during WCPs so that novel pain control strategies can be developed.

BACKGROUND

Wound care procedures such as dressing changes can cause moderate to severe pain in 74% of patients, with nearly half (36%) of all patients experiencing severe pain (rated as 8-10 on a 10-point numeric rating scale) during dressing change. Additionally, clinicians have little direction with current guidelines regarding pain control during WCPs including the selection of the appropriate advanced wound dressings and the appropriate use of analgesics.

DESIGN

This is a cross-sectional study.

METHODS

The National Institute of Nursing Research approved and funded the study June of 2015 and the appropriate Institutional Review Board approved all study protocols prior to funding. Study enrolment is underway at the University of Iowa Hospitals and Clinics with a target of 525 participants. Potential participants must be adults (21+ years) and have a nonburn, nondiabetic foot, full-thickness wound. The research team performs a one-time study dressing change on enrolled participants and collects all study data.

DISCUSSION

This study will allow the development of a tool for clinicians to use to predict severe pain during WCPs and identify biological factors significantly associated with severe pain during WCPs.

Opioids: Modulators of angiogenesis in wound healing and cancer

Opioids are potent drugs that are widely used to control wound or cancer pain. Increasing evidence suggest that opioids mediate clinically relevant effects that go beyond their classical role as analgesics. Of note, opioids appear to modulate angiogenesis - a process that is critical in wound healing and cancer progression. In this review, we focus on pro- and anti-angiogenic facets of opioids that arise from the activation of individual opioid receptors and the usage of individual concentrations or application routes. We overview the still incompletely elucidated mechanisms of these angiogenic opioid actions. Moreover, we describe plausible opioids effects, which - although not primarily studied in the context of vessel formation - may be related to the opioid-driven processes of angiogenesis. Finally we discuss the use of opioids as an innovative therapeutic avenue for the treatment of chronic wounds and cancer.

The Roles of Opioid Receptors in Cutaneous Wound Healing

The process of recovery from skin wounding can be protracted and painful, and scarring may lead to weakness of the tissue, unpleasant sensations such as pain or itch, and unfavorable cosmetic outcomes. Moreover, some wounds simply fail to heal and become a chronic burden for the sufferer. Understanding the mechanisms underlying wound healing and the concomitant sensory disorders and how they might be manipulated for therapeutic benefit has attracted much interest in recent years, and here we discuss the latest developments in the field, focusing on the emergent roles of the peripheral opioid receptor (OPr) system.

Pathogenesis of wound healing disorders in the elderly

The elderly constitute the age group most susceptible to wound healing disorders and chronic wounds, the most prevalent being venous leg ulcers, pressure ulcers, and diabetic foot ulcers. However, other age-associated diseases should also be taken into consideration in the diagnostic workup of chronic wounds, and not be underestimated. A better understanding of the pathomechanisms involved in the wound healing process is of key importance in combatting the difficulties associated with the treatment of chronic wounds. In recent decades, considerable progress has been made in the development of pioneering therapeutic strategies for chronic wounds. In this context, the use of growth factors and cytokines, tissue engineering, and cell therapy - including stem cells - have proven very promising. Nevertheless, prior to their introduction into routine clinical practice, large controlled clinical trials are required to assess the safety of these techniques.

Does Opioid Use Cause Angiogenesis and Metastasis?

Objective

To provide a comprehensive overview of the potential for morphine to lead to angiogenesis and metastasis.

Background

Morphine is often the treatment of choice for severe cancer-related pain. Small studies have been emerging that indicate that opioids may influence angiogenesis and metastasis, but this has not yet been comprehensively synthesized.

Purpose

To highlight morphine's relationship with angiogenesis and metastasis in in vitro models.

Method

A review of the literature was conducted using PubMed (1966 to 2015) and Cochrane Library (1987 to 2015) electronic databases. The search, as well as consultation with experts, yielded 84 articles for initial review, 12 of which met inclusion for review. Possible theories of the underlying etiology of the metastasis and angiogenesis were recorded.

Results

All studies were assessed using the PRISMA checklist.

Conclusion

This systematic review demonstrates that morphine has a potential causal relationship with angiogenesis and metastasis. This is likely due to multiple etiologies, including immunosuppressive, pro-inflammatory, and pro-angiogenetic.

Quercetin inhibits gout arthritis in mice: induction of an opioid-dependent regulation of inflammasome

We investigated the anti-inflammatory and analgesic effects of quercetin in monosodium urate crystals (MSU)-induced gout arthritis, and the sensitivity of quercetin effects to naloxone, an opioid receptor antagonist. Mice were treated with quercetin, and mechanical hyperalgesia was assessed at 1-24 h after MSU injection. In vivo, leukocyte recruitment, cytokine levels, oxidative stress, NFκB activation, and gp91phox and inflammasome components (NLRP3, ASC, Pro-caspase-1, and Pro-IL-1β) mRNA expression by qPCR were determined in the knee joints at 24 h after MSU injection. Inflammasome activation was determined, in vitro, in lipopolysaccharide-primed macrophages challenged with MSU. Quercetin inhibited MSU-induced mechanical hyperalgesia, leukocyte recruitment, TNFα and IL-1β production, superoxide anion production, inflammasome activation, decrease of antioxidants levels, NFκB activation, and inflammasome components mRNA expression. Naloxone pre-treatment prevented all the inhibitory effects of quercetin over MSU-induced gout arthritis. These results demonstrate that quercetin exerts analgesic and anti-inflammatory effect in the MSU-induced arthritis in a naloxone-sensitive manner.

Relationship between opioid treatment and rate of healing in chronic wounds

Opioids are routinely used analgesics in patients with chronic wounds; however the impact of opioid exposure on wound healing is poorly understood. The purpose of this study was to investigate the association between opioid exposure and wound outcome in the Wound Etiology and Healing study. This longitudinal observational study was conducted on 450 subjects enrolled in the Wound Etiology and Healing biorepository. Data were collected prospectively including baseline characteristics, pain score, longitudinal opioid exposure, and total wound surface area (tWSA). Data were analyzed using static multivariate models, fixed-effects mixed models, and time to event analysis. Using fixed-effects models, opioid dose was significantly associated with tWSA after accounting for the effects of pain score and baseline co-variates (p < 0.0001). For each 1-unit increase in ln(opioid dose + 1) the ln(tWSA + 1) increased by 0.16 units (95% confidence interval 0.13-0.19, p < 0.0001). Visits where opioids were present had ln(tWSA + 1) 0.48 units larger (95% confidence interval 0.38-0.58, p < 0.0001) than visits with no opioid exposure. Using time-to-event analysis, patients who never received opioids healed faster than those who received opioids (log-rank chi-square 11.00, p  = 0.0009). Using Cox regression analysis, patients with mean opioid dose ≥10 mg were significantly less likely to heal than those with no opioid (HR 0.67 [0.49-0.91], p = 0.011) after adjusting for wound size. Patients with opioid dose >0 to <10 mg had a similar hazard of not healing as those with no opioid exposure (HR 0.88 [0.65-1.19], p = 0.40). In conclusion, opioid analgesics are commonly prescribed to patients with chronic wounds; however, the data presented suggest that opioid exposure is associated with reduced likelihood of healing in patients with chronic wounds. Whether this is a causal relationship will require further study.

Gut Homeostasis, Microbial Dysbiosis, and Opioids

Gut homeostasis plays an important role in maintaining animal and human health. The disruption of gut homeostasis has been shown to be associated with multiple diseases. The mutually beneficial relationship between the gut microbiota and the host has been demonstrated to maintain homeostasis of the mucosal immunity and preserve the integrity of the gut epithelial barrier. Currently, rapid progress in the understanding of the host-microbial interaction has redefined toxicological pathology of opioids and their pharmacokinetics. However, it is unclear how opioids modulate the gut microbiome and metabolome. Our study, showing opioid modulation of gut homeostasis in mice, suggests that medical interventions to ameliorate the consequences of drug use/abuse will provide potential therapeutic and diagnostic strategies for opioid-modulated intestinal infections. The study of morphine's modulation of the gut microbiome and metabolome will shed light on the toxicological pathology of opioids and its role in the susceptibility to infectious diseases.