Opioid therapy and immunosuppression: a review

In utero opioid exposure and risk of infections in childhood: A multinational Nordic cohort study

PURPOSE

There is an increasing number of children with in utero exposure to opioids. Knowledge about opioid safety in pregnancy, particularly for outcomes later in childhood is scarce. It has been suggested that opioids can modulate immune system and increase the risk of infections. Our goal was to study the impact of in utero opioid exposure on the immune system and the risk of infections in childhood.

METHODS

This population-based cohort study used nationwide registers from Denmark, Norway, and Sweden. Among pregnant women we identified users of opioids for two different indications, opioids used in opioid maintenance therapy (OMT) and opioids used for treatment of pain. We followed the exposed children and studied susceptibility for infections measured as number of antibiotic prescriptions expressed as Incidence rate ratios (IRRs) and diagnoses in specialist health care expressed as hazard ratios (HRs).

RESULTS

After adjustment we did not observe increased risk for filling antibiotic prescriptions in children exposed to OMT opioids compared with OMT discontinuers (IRR, 1.08; 95% CI 0.81-1.44 in Norway and Sweden, and IRR, 0.74; 95% CI 0.63-0.88 in Denmark), or for diagnosis of infection in specialist health care (HR 0.83; 95% CI 0.55-1.26 in Norway and Sweden, and 0.82; 95% CI 0.62-1.10 in Denmark).

CONCLUSIONS

In this population-based cohort study, we did not observe increased risk of infections among children prenatally exposed to OMT opioids when compared to OMT discontinuers, nor long-term analgesic opioids exposed when compared to short-term analgesic opioids exposed.

Opioid-free spine surgery: a prospective study of 244 consecutive cases by a single surgeon

BACKGROUND CONTEXT

There have been no reported efforts to eliminate opioid use for elective spine surgery, despite its well-known drawbacks.

PURPOSE

We sought to test the hypothesis that opioid-free elective spine surgery, including lumbar fusions, can be performed with satisfactory pain control.

STUDY DESIGN/ SETTING

This study analyzes prospectively collected data from a single surgeon's patients who were enrolled into an institutional spine registry.

PATIENT SAMPLE

We enrolled every consecutive surgical patient of author RAB between January 1, 2018 and July 13, 2019.

OUTCOME MEASURES

The postsurgical opioid use, pain scores, emergency room visits, and readmissions were tracked.

METHODS

We developed a comprehensive program for opioid-free pain control after elective spine surgery. In the initial stage, opioids were given "PRN" only, while in the second stage, they were avoided altogether. Student's t tests were performed to compare pain scores, and regression analyses were performed to understand drivers of opioid use and pain.

RESULTS

Two hundred forty-four patients were studied, a third of whom underwent lumbar fusions. In the initial stage, 47% of patients took no opioids from recovery room departure until 1-month follow-up. During the second stage, 88% of patients took no opioids during that period. Pain scores were satisfactory, and there was no association between postoperative opioid use and either procedural invasiveness or pain scores. However, preoperative opioid use was associated with a nearly fivefold increased risk of postoperative use. Ninety-three percent of lumbar fusion patients who were opioid-free before surgery did not take a single opioid in the postoperative period.

CONCLUSION

Opioid-free elective spine surgery, including lumbar fusions, is feasible and effective. We suggest that opioid-free spine surgery be offered to patients who are opioid-naïve or who can be weaned off before the operation.

The "Culture" of Pain Control: A Review of Opioid-Induced Dysbiosis (OID) in Antinociceptive Tolerance

It is increasingly recognized that chronic opioid use leads to maladaptive changes in the composition and localization of gut bacteria. Recently, this "opioid-induced dysbiosis" (OID) has been linked to antinociceptive tolerance development in preclinical models and may therefore identify promising targets for new opioid-sparing strategies. Such developments are critical to curb dose escalations in the clinical setting and combat the ongoing opioid epidemic. In this article, we review the existing literature that pertains to OID, including the current evidence regarding its qualitative nature, influence on antinociceptive tolerance, and future prospects. PERSPECTIVE: This article reviews the current literature on OID of gut bacteria, including its qualitative nature, influence on antinociceptive tolerance, and future prospects. This work may help identify targets for new opioid-sparing strategies.

Potential of Glial Cell Modulators in the Management of Substance Use Disorders

The pervasive and devastating nature of substance use disorders underlies the need for the continued development of novel pharmacotherapies. We now know that glia play a much greater role in neuronal processes than once believed.  The various types of glial cells (e.g., astrocytes, microglial, oligodendrocytes) participate in numerous functions that are crucial to healthy central nervous system function. Drugs of abuse have been shown to interact with glia in ways that directly contribute to the pharmacodynamic effects responsible for their abuse potential. Through their effect upon glia, drugs of abuse also alter brain function resulting in behavioral changes associated with substance use disorders. Therefore, drug-induced changes in glia and inflammation within the central nervous system (neuroinflammation) have been investigated to treat various aspects of drug abuse and dependence. This article presents a brief overview of the effects of each of the major classes of addictive drugs on glia. Next, the paper reviews the pre-clinical and clinical studies assessing the effects that glial modulators have on abuse-related behavioral effects, such as pleasure, withdrawal, and motivation. There is a strong body of pre-clinical literature demonstrating the general effectiveness of several glia-modulating drugs in models of reward and relapse. Clinical studies have also yielded promising results, though not as robust. There is still much to disentangle regarding the integration between addictive drugs and glial cells. Improved understanding of the relationship between glia and the pathophysiology of drug abuse should allow for more precise exploration in the development and testing of glial-directed treatments for substance use disorders.

Opioid Analgesics Adverse Effects: The Other Side of the Coin

BACKGROUND

Opioids are the cornerstone of the management of cancer pain. However, the development of adverse effects may compromise the opioid response. They include nausea and vomiting, constipation, drowsiness, sleep disorders, cognitive dysfunction, myoclonus, pruritus, dysuria, dependence and the development of aberrant behaviors, respiratory depression, and some endocrine responses.

METHODS

The goal of this paper is to identify the most common opioid-related adverse effects, their pathophysiology, and proposing the possible treatments. This narrative review will describe how these adverse effects may develop and how to prevent or to treat.

CONCLUSION

Intensity of adverse effects tend to decrease with continuous use. However, they may be persistent and may require symptomatic treatment or more complex treatment including alternative strategies for pain management.

Opium use and subsequent incidence of cancer: results from the Golestan Cohort Study

BACKGROUND

Evidence is emerging for a role of opiates in various cancers. In this study, we aimed to investigate the association between regular opium use and cancer incidence.

METHODS

This study was done in a population-based cohort of 50 045 individuals aged 40-75 years from northeast Iran. Data on participant demographics, diet, lifestyle, opium use, and different exposures were collected upon enrolment using validated questionnaires. We used proportional hazards regression models to estimate hazard ratios (HRs) and corresponding 95% CIs for the association between opium use and different cancer types.

FINDINGS

During a median 10 years of follow-up, 1833 participants were diagnosed with cancer. Use of opium was associated with an increased risk of developing all cancers combined (HR 1·40, 95% CI 1·24-1·58), gastrointestinal cancers (1·31, 1·11-1·55), and respiratory cancers (2·28, 1·58-3·30) in a dose-dependent manner (ptrend<0·001). For site-specific cancers, use of opium was associated with an increased risk of developing oesophageal (1·38, 1·06-1·80), gastric (1·36, 1·03-1·79), lung (2·21, 1·44-3·39), bladder (2·86, 1·47-5·55), and laryngeal (2·53, 1·21-5·29) cancers in a dose-dependent manner (ptrend<0·05). Only high-dose opium use was associated with pancreatic cancer (2·66, 1·23-5·74). Ingestion of opium (but not smoking opium) was associated with brain (2·15, 1·00-4·63) and liver (2·46, 1·23-4·95) cancers in a dose-dependent manner (prend<0·01). We observed consistent associations among ever and never tobacco users, men and women, and individuals with lower and higher socioeconomic status.

INTERPRETATION

Opium users have a significantly higher risk of developing cancers in different organs of the respiratory, digestive, and urinary systems and the CNS. The results of this analysis show that regular use of opiates might increase the risk of a range of cancer types.

FUNDING

World Cancer Research Fund International, Cancer Research UK, Tehran University of Medical Sciences, US National Cancer Institute, International Agency for Research on Cancer.

δ-Opioid Receptors, microRNAs, and Neuroinflammation in Cerebral Ischemia/Hypoxia

Hypoxia and ischemia are the main underlying pathogenesis of stroke and other neurological disorders. Cerebral hypoxia and/or ischemia (e.g., stroke) can lead to neuronal injury/death and eventually cause serious neurological disorders or even death in the patients. Despite knowing these serious consequences, there are limited neuroprotective strategies against hypoxic and ischemic insults in clinical settings. Recent studies indicate that microRNAs (miRNAs) are of great importance in regulating cerebral responses to hypoxic/ischemic stress in addition to the neuroprotective effect of the δ-opioid receptor (DOR). Moreover, new discovery shows that DOR can regulate miRNA expression and inhibit inflammatory responses to hypoxia/ischemia. We, therefore, summarize available data in current literature regarding the role of DOR and miRNAs in regulating the neuroinflammatory responses in this article. In particular, we focus on microglia activation, cytokine production, and the relevant signaling pathways triggered by cerebral hypoxia/ischemia. The intent of this review article is to provide a novel clue for developing new strategies against neuroinflammatory injury resulting from cerebral hypoxia/ischemia.

Use of Flavored Tablets of Gabapentin and Carprofen to Attenuate Postoperative Hypersensitivity in an Incisional Pain Model in Rats (Rattus norvegicus)

Providing postoperative analgesia to rats by oral administration, compared with injections, reduces stress from frequent handling and is technically easier for investigators. The purpose of this study was to investigate whether bacon-flavored tablets containing gabapentin, carprofen or a combination of both drugs effectively attenuates postoperative mechanical and thermal hypersensitivity in a rat model of incisional pain. Forty-eight Sprague-Dawley rats were randomly assigned to 1 of 5 treatment groups: placebo tablet; a single, subcutaneous injection of buprenorphine sustained release at 1.2 mg/kg; gabapentin 90 mg/tablet; carprofen 5 mg/tablet; gabapentin 90 mg and carprofen 5 mg/tablet (gabapentin/carprofen). Tablets were given to rats on days -3, -2, -1, 0 (surgery), 1, and 2. Rats were anesthetized using isoflurane. A 1 cm skin incision was made aseptically on the plantar surface of the left hindpaw and closed by using suture. Mechanical (von Frey monofilament) and thermal (Hargreaves method) hypersensitivity were tested daily, and analyzed on days -1, 1, 2, and 3. The amount of tablet consumed was recorded daily; postoperatively rats consumed 101 to 133 mg/kg of gabapentin, 5.5 to 5.8 mg/kg of carprofen, and 86-137/1.9-3 mg/kg of gabapentin/carprofen, respectively. Both the gabapentin and carprofen groups displayed attenuated mechanical hypersensitivity on all 3 postsurgical days and decreased thermal hypersensitivity on Day 3. The gabapentin/ carprofen group showed attenuated mechanical hypersensitivity on Day 2 and 3, but no significant reduction of thermal hypersensitivity. These data suggest that both gabapentin and carprofen, given orally by flavored tablet, effectively attenuate postoperative mechanical hypersensitivity for 3 d after surgery in a rat model of incisional pain.

Differential Use of Narcotics in Total Hip Arthroplasty: A Comparative Matched Analysis Between Osteoarthritis and Femoral Neck Fracture

BACKGROUND

The United States is currently in an opioid epidemic as it consumes the majority of narcotic medications. The purpose of this investigation is to identify the incidence and risk factors for prolonged opioid usage following total hip arthroplasty (THA) due to hip fracture (Fx) or osteoarthritis (OA).

METHODS

The PearlDiver database was reviewed for patients undergoing THA from 2007 through the first quarter of 2017. Following a 3:1 match based on comorbidities and demographics, patients were divided into THA due to Fx (n = 1801) or OA (n = 5403). Preoperative and prolonged postoperative narcotic users were identified. Multivariate logistic regression analysis was performed to identify demographics, comorbidities, or diagnoses as risk factors for prolonged opioid use and preoperative and postoperative opioid use as risk factors for complications.

RESULTS

One thousand seven hundred ninety-four OA patients (33.2%) were prescribed narcotics preoperatively and 1655 patients (30.6%) were using narcotics postoperatively, while 418 Fx patients (23.2%) were prescribed narcotics preoperatively and 499 patients (27.7%) were using narcotics postoperatively. Diagnosis of Fx (odds ratio [OR] 1.51, 95% confidence interval [CI] 1.28-1.72, P < .001) and preoperative narcotic use (OR 6.12, 95% CI 5.27-6.82, P < .001) were the most significant risk factors for prolonged postoperative narcotic use. Prolonged postoperative narcotic use was associated with increased infection, dislocation, and revision THA in both Fx and OA groups.

CONCLUSION

Diagnosis of femoral neck fracture and overall preoperative narcotic use were significant predictors of chronic postoperative opioid use. Patients with significant risk factors for opioid dependence should receive additional consultation and more prudent follow-up with regards to pain management.

LEVEL OF EVIDENCE

Therapeutic, Level III.

Opioid Use Disorder and COVID-19: Biological Plausibility for Worsened Outcomes

Alarms have been raised that COVID-19 may disproportionately affect certain populations with substance use disorders, particularly Opioid Use Disorder (OUD), however warnings have largely focused on social risks such as reduced availability of services. Objectives: This commentary highlights three plausible biological mechanisms for potentially worsened outcomes in patients with OUD who contract COVID-19. Results: Opioid-related respiratory depression may amplify risks of hypoxemia from COVID-19 viral pneumonia. Complex opioid immune modulation may impact host response to COVID-19, though the effect direction and clinical significance are unclear. Drug-drug interactions may affect individuals with OUD who are co-administered medications for OUD and medications for COVID-19, particularly due to cardiac adverse effects. Conclusions/Importance: There are plausible biological mechanisms for potentially worsened outcomes in patients with OUD who contract COVID-19; these mechanisms require further study, and should be considered in individuals with OUD.

Do All Opioid Drugs Share the Same Immunomodulatory Properties? A Review From Animal and Human Studies

Suppression of the immune system has been constantly reported in the last years as a classical side effect of opioid drugs. Most of the studies on the immunological properties of opioids refer to morphine. Although morphine remains the "reference molecule," other semisynthetic and synthetic opioids are frequently used in the clinical practice. The primary objective of this review is to analyze the available literature on the immunomodulating properties of opioid drugs different from morphine in preclinical models and in the human. A search strategy was conducted in PubMed, Embase, and the Cochrane databases using the terms "immunosuppression," "immune system," "opioids," "Natural killer cells," "cytokines," and "lymphocytes." The results achieved concerning the effects of fentanyl, methadone, oxycodone, buprenorphine, remifentanil, tramadol, and tapentadol on immune responses in animal studies, in healthy volunteers and in patients are reported. With some limitations due to the different methods used to measure immune system parameters, the large range of opioid doses and the relatively scarce number of participants in the available studies, we conclude that it is not correct to generalize immunosuppression as a common side effect of all opioid molecules.

The effects of long-term opioid treatment on the immune system in chronic non-cancer pain patients: A systematic review

BACKGROUND AND OBJECTIVE

Opioids have been increasingly prescribed for chronic non-cancer pain (CNCP). An association between long-term opioid treatment (L-TOT) of CNCP patients and suppression of both the innate and the adaptive immune system has been proposed. This systematic review aims at investigating the effects of L-TOT on the immune system in CNCP patients.

DATABASES AND DATA TREATMENT

A systematic search of MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and the CINAHL for relevant articles was performed. Studies examining measures of both the innate and the adaptive immune system in adult CNCP patients in L-TOT (≥4 weeks of intake) were included. Outcomes and the level of evidence were analysed.

RESULTS

A total of 382 studies were identified; however, 376 were excluded (352 inappropriate methodology, 21 duplicates, three full-text could not be obtained) and one randomized controlled trial (RCT) and five cross-sectional studies were included and analysed. L-TOT compared with no treatment was associated with a lower percentage of natural killer (NK) cells, a lower absolute number of CD56^bright NK cells, a higher absolute number of IL-2-activated NK cells and a higher concentration of IL-1β as a response to toll-like receptor (TLR) agonists stimulation (Pam3CSK4, LPS, Imiquimod). No other significant differences were reported. Generalizability of the results was limited due to inconsistency of outcomes and an overall low quality of the studies.

CONCLUSIONS

L-TOT may alter the immune system in CNCP patients, but the level of evidence is still weak. More studies are needed to clarify the impact of L-TOT on immune system function.

SIGNIFICANCE

This systematic review found indication that long-term opioid treatment alters the immune system in chronic non-cancer pain patients. These alterations involved the NK cells and IL-1β production. However, the level of evidence is weak.

The Influence of Pain and Analgesia in Rodent Models of Sepsis

Sepsis is a multifaceted host response to infection that dramatically affects patient outcomes and the cost of health care. Animal models are necessary to replicate the complexity and heterogeneity of clinical sepsis. However, these models entail a high risk of pain and distress due to tissue trauma, inflammation, endotoxin-mediated hyperalgesia, and other mechanisms. Several recent studies and initiatives address the need to improve the welfare of animals through analgesics and standardize the models used in preclinical sepsis research. Ultimately, the goal is to provide high-fidelity, humane animal models that better replicate the clinical course of sepsis, to provide more effective translation and advance therapeutic discovery. The purpose of this review is to discuss the current understanding of the roles of pain and analgesia in rodent models of sepsis. The current definitions of sepsis along with an overview of pain in human sepsis are described. Finally, welfare concerns associated with animal models of sepsis and the most recent considerations for relief of pain and distress are reviewed.

Nalbuphine for Analgesia After Orthognathic Surgery and Its Effect on Postoperative Inflammatory and Oxidative Stress: A Randomized Double-Blind Controlled Trial

PURPOSE

Postoperative pain is a negative factor that seriously affects a surgical patient's rehabilitation. We investigated whether nalbuphine provides superior postoperative analgesia in orthognathic surgery compared with sufentanil and whether the superior analgesia is achieved by the regulation of inflammatory and oxidative stress.

PATIENTS AND METHODS

In the present randomized, double-blind, controlled clinical trial, 60 patients scheduled to undergo orthognathic surgery were randomized to receive 2.5 μg/kg of sufentanil (group S) or 2 mg/kg of nalbuphine (group N) for postoperative controlled intravenous analgesia. The primary outcome variable was the visual analog scale (VAS) score. The secondary outcome variables included the sedation score (Ramsay score) and plasma levels of inflammation factors, including tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and oxidant stress factors, including malondialdehyde (MDA) and superoxide dismutase (SOD).

RESULTS

The VAS scores of group N were significantly lower than those of group S, and the Ramsay scores for group N were greater. The plasma levels of TNF-α, IL-6, and MDA for group N were significantly lower than those for group S, and the SOD levels were greater than those for group S. Furthermore, the VAS scores correlated positively with the plasma levels of TNF-α, IL-6, and MDA and correlated negatively with the SOD levels.

CONCLUSIONS

Nalbuphine offers better postoperative analgesia and sedation after orthognathic surgery. Nalbuphine also seems to provide superior postoperative analgesia by reducing inflammatory and oxidative stress.

Immunomodulatory Effects of Surgery, Pain, and Opioids in Cancer Patients

Surgery is the mainstay of therapy for canine and human solid cancers. Alarmingly, evidence suggests that the process of surgery may exacerbate metastasis and accelerate the kinetics of cancer progression. Understanding the mechanisms by which cancer progression is accelerated as a result of surgery may provide pharmacologic interventions. This review discusses surgery-induced cancer progression. It focuses on immunomodulatory properties of anesthesia and opioids and evidence that studies evaluating the role of opioids in tumor progression are indicated. It concludes by discussing why companion animals with spontaneously arising cancer are an ideal model for clinical trials to investigate this phenomenon.

Integrative analysis of genetic and epigenetic profiling of lung squamous cell carcinoma (LSCC) patients to identify smoking level relevant biomarkers

Background

Incidence and mortality of lung cancer have dramatically decreased during the last decades, yet still approximately 160,000 deaths per year occurred in United States. Smoking intensity, duration, starting age, as well as environmental cofactors including air-pollution, showed strong association with major types of lung cancer. Lung squamous cell carcinoma is a subtype of non-small cell lung cancer, which represents 25% of the cases. Thus, exploring the molecular pathogenic mechanisms of lung squamous cell carcinoma plays crucial roles in lung cancer clinical diagnosis and therapy.

Results

In this study, we performed integrative analyses on 299 comparative datasets of RNA-seq and methylation data, collected from 513 lung squamous cell carcinoma cases in The Cancer Genome Atlas. The data were divided into high and low smoking groups based on smoking intensity (Numbers of packs per year). We identified 1002 significantly up-regulated genes and 534 significantly down-regulated genes, and explored their cellular functions and signaling pathways by bioconductor packages GOseq and KEGG. Global methylation status was analyzed and visualized in circular plot by CIRCOS. RNA-and methylation data were correlatively analyzed, and 24 unique genes were identified, for further investigation of regional CpG sites' interactive patterns by bioconductor package coMET. AIRE, PENK, and SLC6A3 were the top 3 genes in the high and low smoking groups with significant differences.

Conclusions

Gene functions and DNA methylation patterns of these 24 genes are important and useful in disclosing the differences of gene expression and methylation profiling caused by different smoking levels.

Effect of Equipotent Doses of Propofol versus Sevoflurane Anesthesia on Regulatory T Cells after Breast Cancer Surgery

WHAT WE ALREADY KNOW ABOUT THIS TOPIC

WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Clusters of differentiation 39 and 73, enzymes expressed on the surface of regulatory T cells, promote cancer recurrence and metastasis by suppressing immune cells. The authors hypothesized that propofol is less immunosuppressive than volatile anesthetics. The objective of this randomized trial was to compare the changes in cluster of differentiation 39 and 73 expression on regulatory T cells between propofol- and sevoflurane-based anesthesia during breast cancer surgery.

METHODS

A total of 201 patients having breast cancer surgery were randomly assigned and analyzed (n = 99 for propofol, n = 102 for sevoflurane). Blood samples were obtained immediately before anesthesia induction and 1 and 24 h postoperatively. The frequency of cluster of differentiation 39 and 73 expression on circulating regulatory T cells (primary outcome) and the frequency of circulating type 1 and type 17 helper T cells, natural killer cells, and cytotoxic T cells were investigated. Serum cytokines and the neutrophil-to-lymphocyte ratio were also evaluated.

RESULTS

Changes in cluster of differentiation 39 and 73 expression on regulatory T cells over time did not differ with propofol and sevoflurane groups (difference [95% confidence interval]: 0.01 [-2.04 to 2.06], P = 0.995 for cluster of differentiation 39; -0.93 [-3.12 to 1.26], P = 0.403 for cluster of differentiation 73). There were no intergroup differences in type 1, type 17 helper T cells, natural killer cells, cytotoxic T cells, cytokines, or the neutrophil-to-lymphocyte ratio.

CONCLUSIONS

Changes in immune cells were similar with propofol and sevoflurane during breast cancer surgery. The effect of anesthetics on the perioperative immune activity may be minimal during cancer surgery.

Thoracic epidural anaesthesia and analgesia ameliorates surgery-induced stress response and postoperative pain in patients undergoing radical oesophagectomy

Objective

An acute severe stress response associated with major surgery can adversely affect the inflammatory and hormonal responses. We hypothesised that total intravenous anaesthesia (TIVA) combined with thoracic epidural anaesthesia and analgesia (TEA) attenuates the stress response and postoperative pain in patients undergoing radical oesophagectomy.

Methods

Forty patients scheduled for elective radical oesophagectomy were randomly assigned to one of two groups: TIVA or TIVA+TEA. The plasma levels of stress hormones and cytokines, consumption of fentanyl, postoperative visual analogue scale (VAS) scores within 48 hours, and extubation time were assessed.

Results

The plasma levels of interleukin-6, norepinephrine, cortisol, and adrenocorticotropic hormone at 3 hours after the beginning of surgery were significantly higher in the TIVA group than TIVA+TEA group. The plasma level of interleukin-10 at 3 hours after the beginning of surgery was significantly lower in the TIVA group than TIVA+TEA group. The consumption of fentanyl was significantly greater, VAS scores were significantly higher, and extubation time was significantly longer in the TIVA group than TIVA+TEA group.

Conclusions

The findings suggest that combination of TIVA and TEA may attenuate the intraoperative stress response and postoperative pain in patients undergoing radical oesophagectomy.

Role of anti-oxidant (vitamin-C) in post-operative pain relief in foot and ankle trauma surgery: A prospective randomized trial

BACKGROUND

Post-operative pain may adversely affect a patient's quality of life. Studies have shown that vitamin C, being an anti-oxidant and neuro-modulating agent, can help to reduce pain in a variety of clinical settings. The objective of this randomized controlled trial was to assess the effectiveness of vitamin C in reducing post-operative pain, analgesia requirements and improving functional outcome.

METHODS

Patients with isolated foot and ankle trauma, who had undergone surgery, were randomly assigned to receive either vitamin C 500mg or a placebo tablet twice a day. VAS score, analgesia requirement and functional outcome were assessed during their regular follow up. Results were compared and analyzed at the end of 3 months.

RESULTS

The group which received vitamin C, showed improvement in VAS score at the end of second and sixth week of follow up, reduced analgesia requirements and improved functional outcome as compared to the placebo group.

CONCLUSIONS

This study shows that the supplementation of vitamin C in patients undergoing surgery for foot and ankle trauma helps to reduce analgesic requirements, improve VAS scores and achieve better functional outcome.

Characterization of 17-Cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6α-(indole-7-carboxamido)morphinan (NAN) as a Novel Opioid Receptor Modulator for Opioid Use Disorder Treatment

The opioid crisis is a significant public health issue with more than 115 people dying from opioid overdose per day in the United States. The aim of the present study was to characterize the in vitro and in vivo pharmacological effects of 17-cyclopropylmethyl-3,14β-dihydroxy-4,5α-epoxy-6α-(indole-7-carboxamido)morphinan (NAN), a μ opioid receptor (MOR) ligand that may be a potential candidate for opioid use disorder treatment that produces less withdrawal signs than naltrexone. The efficacy of NAN was compared to varying efficacy ligands at the MOR, and determined at the δ opioid receptor (DOR) and κ opioid receptor (KOR). NAN was identified as a low efficacy partial agonist for G-protein activation at the MOR and DOR, but had relatively high efficacy at the KOR. In contrast to high efficacy MOR agonists, NAN did not induce MOR internalization, downregulation, or desensitization, but it antagonized agonist-induced MOR internalization and stimulation of intracellular Ca2+ release. Opioid withdrawal studies conducted using morphine-pelleted mice demonstrated that NAN precipitated significantly less withdrawal signs than naltrexone at similar doses. Furthermore, NAN failed to produce fentanyl-like discriminative stimulus effects in rats up to doses that produced dose- and time-dependent antagonism of fentanyl. Overall, these results provide converging lines of evidence that NAN functions mainly as a MOR antagonist and support further consideration of NAN as a candidate medication for opioid use disorder treatment.

Analgesic adjuvants modulate morphine-induced immune effects in mice

BACKGROUND

Macrophages, involved in the pathogenesis of pain, express a variety of receptors enabling responsiveness to certain medications, including adjuvant analgesics (AAs), that are effective in neuropathic pain and include drugs not primarily indicated for pain treatment, such as anticonvulsants or antidepressants. Their analgesic effects are likely associated with immunomodulatory activity, that remain undefined. Thus, current research aimed at examining the impact of AAs on morphine-induced effects exerted on mouse immunity.

METHODS

Macrophages from mice treated with morphine with or without gabapentin, amitriptyline or venlafaxine, were either subjected to phagocytosis assay, cultured to evaluate the generation of cytokines, or were pulsed with either corpuscular antigen or hapten and transferred to naive recipients to induce humoral or cellular response, respectively. Active contact hypersensitivity was also elicited in drug-treated mice.

RESULTS

We observed that repeatedly administered morphine and AAs reduced antigen phagocytosis by macrophages. Further, amitriptyline with morphine enhanced basal secretion of cytokines by macrophages, and all drugs tended to decrease LPS-stimulated release of pro-inflammatory cytokines. Morphine and AAs impacted the expression of phagocytosis and antigen-presentation markers on macrophages, which led to the reduced ability of morphine-affected macrophages to induce B-cell secretion of specific antibodies, and the addition of AAs strengthened this effect. Finally, gabapentin and venlafaxine suppressed the contact hypersensitivity reaction, while amitriptyline seemed to have the opposite effect.

CONCLUSIONS

Our study demonstrated a significant anti-inflammatory activity of AAs across a broad spectrum of macrophage immune functions, which is likely critical to their analgesic activity supporting the beneficial effect of morphine.

Opioids in the immune system: from experimental studies to clinical practice

INTRODUCTION

Opioids interact with both innate and adaptive immune systems and have direct effects on opioid receptors located on immune cells. Research on this topic has provided evidence of the opioid influence on the immune response associated with surgical stress. The immunological effects of opioids are currently being investigated, particularly whether they influence the outcome of surgery or the underlying disease regarding important aspects like infection or cancer progression. This review addresses background research related to the influence of the opioid receptor on the immune system, the immunosuppressive effect associated with major opioids during the perioperative period, and their clinical relevance. The objective of the study was to review the effects of opioids on the immune system.

Opioid dependency is independently associated with inferior clinical outcomes after trauma

INTRODUCTION

Increased use of opioids has led to higher rates of overdose and hospital admissions. Studies in trauma populations have focused on outcomes associated with acute intoxications rather than addiction. We hypothesize that clinical outcomes after injury would be inferior for opioid-dependent patients compared to opioid-naïve patients.

METHODS

We identified all opioid-dependent adult patients admitted to an academic level I trauma center in 2016 with an Injury Severity Score (ISS) ≥ 5. Patients were further categorized by their pattern of opioid dependency into prescription abuse, illicit abuse, or chronic pain subgroups. Outcome measures included length of stay (LOS), major complications, mortality, non-home discharge, ventilator days, and readmissions. Regression models were adjusted for patient demographics, insurance, ISS, and comorbidities.

RESULTS

Of the 1450 patients who met the inclusion criteria, 18% were opioid-dependent. Among opioid-dependent patients, 30%, 27%, and 43% were prescription abuse, illicit abuse, and chronic pain patients, respectively. Compared to opioid-naïve (non-users) patients, opioid-dependent patients had longer LOS, more ventilator days, more non-home discharges, and higher readmission rates. Subgroup analysis revealed significant differences among all cohorts when compared to non-users in LOS, non-home discharge, readmissions, and major complications. Opioid dependency was not associated with mortality.

CONCLUSION

Opioid dependency was detected in 18% of trauma patients and was independently associated with inferior outcomes. The impact of opioid dependency affects each opioid subgroup differently with all cohorts demonstrating increased 30-day readmissions. Opioid dependent patients may be targeted for risk interventions to reduce LOS, non-home discharge, complications and readmissions.

Perioperative Inflammation and Its Modulation by Anesthetics

Surgery and other invasive procedures, which are routinely performed during general anesthesia, may induce an inflammatory response in the patient. This inflammatory response is an inherent answer of the body to the intervention and can be both beneficial and potentially harmful. The immune system represents a unique evolutionary achievement equipping higher organisms with an effective defense mechanism against exogenous pathogens. However, not only bacteria might evoke an immune response but also other noninfectious stimuli like the surgical trauma or mechanical ventilation may induce an inflammatory response of varying degree. In these cases, the immune system activation is not always beneficial for the patients and might carry the risk of concomitant, harmful effects on host cells, tissues, or even whole organ systems. Research over the past decades has contributed substantial information in which ways surgical patients may be affected by inflammatory reactions. Modulations of the patient's immune system may be evoked by the use of anesthetic agents, the nature of surgical trauma and the use of any supportive therapy during the perioperative period. The effects on the patient may be manifold, including various proinflammatory effects. This review focuses on the causes and effects of inflammation in the perioperative period. In addition, we also highlight possible approaches by which inflammation in the perioperative may be modulated in the future.

Nociceptin/Orphanin FQ (N/OFQ) conjugated to ATTO594: a novel fluorescent probe for the N/OFQ (NOP) receptor

BACKGROUND AND PURPOSE

The nociceptin/orphanin FQ (N/OFQ) receptor (NOP) is a member of the opioid receptor family and is involved in a number of physiological responses, pain and immune regulation as examples. In this study, we conjugated a red fluorophore-ATTO594 to the peptide ligand N/OFQ (N/OFQATTO594 ) for the NOP receptor and explored NOP receptor function at high (in recombinant systems) and low (on immune cells) expression.

EXPERIMENTAL APPROACH

We assessed N/OFQATTO594 receptor binding, selectivity and functional activity in recombinant (CHO) cell lines. Live cell N/OFQATTO594 binding was measured in (i) HEK cells expressing NOP and NOPGFP receptors, (ii) CHO cells expressing the hNOPGαqi5 chimera (to force coupling to measurable Ca2+ responses) and (iii) freshly isolated human polymorphonuclear cells (PMN).

KEY RESULTS

N/OFQATTO594 bound to NOP receptor with nM affinity and high selectivity. N/OFQATTO594 activated NOP receptor by reducing cAMP formation and increasing Ca2+ levels in CHOhNOPGαqi5 cells. N/OFQATTO594 was also able to visualize NOP receptors at low expression levels on PMN cells. In NOP-GFP-tagged receptors, N/OFQATTO594 was used in a FRET protocol where GFP emission activated ATTO, visualizing ligand-receptor interaction. When the NOPGFP receptor is activated by N/OFQATTO594 , movement of ligand and receptor from the cell surface to the cytosol can be measured.

CONCLUSIONS AND IMPLICATIONS

In the absence of validated NOP receptor antibodies and issues surrounding the use of radiolabels (especially in low expression systems), these data indicate the utility of N/OFQATTO594 to study a wide range of N/OFQ-driven cellular responses.

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.

A case report of sustained resolution of cancer pain by continuous perineural infusion of local anaesthetic

BACKGROUND

Opioids are currently offered as first-line treatment for chronic pain from cancer. Continuous regional analgesia could be an alternative to opioids. However, the required duration of catheterization and the sustained analgesic effects of this technique after catheter removal have yet to be clarified.

CASE REPORT

We report the case of a patient with a shoulder desmoid tumour for which monitoring of tumour progression was the sole therapeutic strategy. Analgesia took the form of patient-controlled infusion of local anaesthetics through an interscalene catheter. Due to the need of an MRI control 45 days later, the pump was stopped. The persistence of pain relief 48 hr later led to the decision to remove the perineural catheter. No pain was reported by the patient over the following 42 days.

CONCLUSIONS

In this patient, it would seem that continuous analgesia allowed for a sustained resolution of pain from the shoulder-located tumour. One hypothesis is that local anaesthetics play a direct role in the erasure of pain memory. This hypothesis needs to be tested with a large patient cohort.

SIGNIFICANCE

This case report provides new insights into the treatment of cancer pain. The most interesting finding is that the pain did remained absent after 45 days of continuous infusion of local anaesthetics through an interscalene catheter. We postulated that local anaesthetic drugs have an impact on pain memory.

Prevalence and Clinical Outcomes of Common Bile Duct Dilation in Patients Who Use Opium

BACKGROUND

This study aimed to evaluate the association of various opium-related factors with common bile duct (CBD) diameter in individuals who use opium in the general population and investigate the clinical importance and long-term outcomes.

MATERIALS AND METHODS

In this prospective study, 2,400 participants were randomly selected from the Golestan Cohort study. Opium consumption data were recorded. CBD diameter was measured by ultrasound. Transient elastography was performed at enrollment and 3 years later. Participants were followed up for at least 5 years.

RESULTS

A total of 1,599 individuals, aged above 50 years, were enrolled and 167 subjects were users of opium. CBD diameter was significantly higher in users of opium than controls (mean ± standard deviation:5.54 ± 1.95 versus 4.74 ± 1.34mm, P < 0.001). This difference was noted with all opium types, but mostly by users of heroin (P < 0.001). Ingestion of opium caused greater CBD dilatation than inhalation (coefficient: 1.16; 95% CI: 0.05-2.27, P = 0.04 versus coefficient: 0.98; 95% CI: 0.75-1.20, P < 0.001). Transient elastography results did not show any association between fibroscan score change and CBD diameter. No major related malignancy was seen during follow-up.

CONCLUSIONS

This study strengthened the evidence of an association of opium use with increased CBD diameter in a population-based setting without significantly increased risk of pancreaticobiliary malignancies or liver fibrosis. We cautiously suggest that opium-induced CBD dilatation may not require further diagnostic work-up.

Immune function after major surgical interventions: the effect of postoperative pain treatment

INTRODUCTION

Impaired immune function during the perioperative period may be associated with worse short- and long-term outcomes. Morphine is considered a major contributor to immune modulation.

PATIENTS AND METHODS

We performed a pilot study to investigate postoperative immune function by analyzing peripheral blood mononuclear cells' functionality and cytokine production in 16 patients undergoing major abdominal surgery. All patients were treated with intravenous (i.v.) patient-controlled analgesia with morphine and continuous wound infusion with ropivacaine+methylprednisolone for 24 hours. After 24 hours, patients were randomized into two groups, one continuing intrawound infusion and the other receiving only i.v. analgesia. We evaluated lymphoproliferation and cytokine production by peripheral blood mononuclear cells at the end of surgery and at 24 and 48 hours postoperatively.

RESULTS

A significant reduction in TNF-α, IL-2, IFN-γ and lymphoproliferation was observed immediately after surgery, indicating impaired cell-mediated immunity. TNF-α and IFN-γ remained suppressed up to 48 hours after surgery, while a trend to normalization was observed for IL-2 and lymphoproliferation, irrespective of the treatment group. A significant inverse correlation was present between age and morphine and between age and lymphoproliferation. No negative correlation was present between morphine and cytokine production. We did not find any differences within the two groups between 24 and 48 hours in terms of morphine consumption and immune responses.

CONCLUSION

A relevant depression of cell-mediated immunity is associated with major surgery and persists despite optimal analgesia. Even though morphine may participate in immunosuppression, we did not retrieve any dose-related effect.

Opioids and the immune system - friend or foe

Systemically administered opioids are among the most powerful analgesics for treating severe pain. Several negative side effects (respiratory depression, addiction, nausea and confusion) and the risk of opioid-induced hyperalgesia accompany opioid administration. One other side effect is the potential of opioids to suppress the immune response and thereby to increase the vulnerability to infections. The link between opioids and immunosuppression has been investigated both in vitro and in vivo as well as in patients. However, the results are inconsistent: Exogenous opioids such as morphine and fentanyl have been found to impair the function of macrophages, natural killer cells and T-cells and to weaken the gut barrier in vitro and in animal studies. In epidemiological studies, high doses and the initiation of opioid therapy for non-malignant pain have been correlated with a higher risk of infectious diseases such as pneumonia. However clear randomized controlled studies are missing. Furthermore, immune cells including neutrophils, macrophages and T-cells have been shown to secrete endogenous opioid peptides, which then bind to peripheral opioid receptors to relieve inflammatory and neuropathic pain. In addition to cytokines, hormones and bacterial products, the release of opioid peptides is stimulated by the application of exogenous opioids. In summary, there is a reciprocal interaction between the immune system and endogenous as well as exogenous opioids. Further to the existing epidemiological studies, controlled clinical studies are needed in the future to elucidate the role of the opioid-immune system interaction in patients and to determine its clinical relevance.

LINKED ARTICLES

This article is part of a themed section on Emerging Areas of Opioid Pharmacology. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.14/issuetoc.

2017 HIVMA of IDSA Clinical Practice Guideline for the Management of Chronic Pain in Patients Living With HIV

Pain has always been an important part of human immunodeficiency virus (HIV) disease and its experience for patients. In this guideline, we review the types of chronic pain commonly seen among persons living with HIV (PLWH) and review the limited evidence base for treatment of chronic noncancer pain in this population. We also review the management of chronic pain in special populations of PLWH, including persons with substance use and mental health disorders. Finally, a general review of possible pharmacokinetic interactions is included to assist the HIV clinician in the treatment of chronic pain in this population.It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. The Infectious Diseases Society of American considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Increased Neutrophil-lymphocyte and Platelet-lymphocyte Ratios in Male Heroin Addicts: A Prospective Controlled Study

Objective

The neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are markers that can determine the presence of systemic inflammatory response. In this study, we examined the NLR and PLR levels in patients with heroin dependence compared to healthy controls.

Methods

The study sample included 90 male patients with heroin dependence aged 18 to 45 years and 60 healthy subjects who had similar socio-demographic characteristics as the patient group. The diagnoses of heroin dependence and other Axis I psychiatric disorders in the patient and control groups were screened with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (SCID-I). The extent of heroin addiction was assessed with the Addiction Severity Index (ASI).

Results

The mean NLR and PLR levels of patients with heroin dependence were significantly higher than the control subjects (p=0.031 and p<0.001, respectively). Positive correlations were found between NLR, PLR and duration of the disorder.

Conclusion

Our results indicate that inflammatory processes may play a role in the pathophysiology of heroin dependence.

Effect of combined epidural anaesthesia on tumor-infiltrating lymphocytes in lung adenocarcinoma: a prospective exploratory sub-analysis

BACKGROUND

Regional anaesthesia may have advantages in preserving immune function. Tumor-infiltrating lymphocytes (TILs) are considered indicators of immune response in the tumor microenvironment and used as a prognostic marker in patients after cancer surgery. This study investigated the effects of combined epidural anaesthesia on the number of TILs in patients undergoing surgery for lung adenocarcinoma.

METHODS

Patients undergoing radical resection for primary lung cancer were randomized to receive either combined epidural-general anaesthesia (Epi-GA) or general anaesthesia (GA) in an ongoing randomized controlled trial (ChiCTR-TRC-14004136). Excised adenocarcinoma specimens from patients enrolled between 1 June 2015 and 30 November 2015 were selected for immunohistochemical staining of CD8 and FOXP3 molecules. The numbers of positive lymphocytes were counted and expressed as the number of cells per mm² tumor area.

RESULTS

One hundred and twenty-eight patients were recruited and randomized; 64 patients were included in immunohistochemistry analysis (37 received Epi-GA vs. 27 received GA). The number of CD8⁺ T cells was higher in the Epi-GA group than in the GA group (median [interquartile range]: 292.8 [198.0-418.3] vs. 204.7 [131.1-305.8], P = 0.036); whereas the number of FOXP3⁺ T cells was less in the Epi-GA group than in the GA group (37.6 [14.7-92.3] vs. 99.8 [68.9-168.3], P < 0.001).

CONCLUSIONS

For patients undergoing surgery for lung adenocarcinoma under general anesthesia, use of epidural anaesthesia increased CD8⁺ T cells infiltration but decreased FOXP3⁺ T cells accumulation in tumor tissues. Epidural anaesthesia may affect TILs in a manner that preserves immune function.

Opioid Analgesic Use and Risk for Invasive Pneumococcal Diseases: A Nested Case-Control Study

BACKGROUND

Although certain opioid analgesics have immunosuppressive properties and increase the risk for infections in animals, the clinical effects of prescription opioid use on infection risk among humans are unknown.

OBJECTIVE

To test the hypothesis that prescription opioid use is an independent risk factor for invasive pneumococcal disease (IPD).

DESIGN

Nested case-control study.

SETTING

Tennessee Medicaid database linked to Medicare and Active Bacterial Core surveillance system databases (1995 to 2014).

PATIENTS

1233 case patients with IPD aged 5 years and older matched to 24 399 control participants by diagnosis date, age, and county of residence.

MEASUREMENTS

Opioid use was measured on the basis of pharmacy prescription fills. Invasive pneumococcal disease was defined by the isolation of Streptococcus pneumoniae from a normally sterile site. The odds of current opioid use were compared between the case and control groups, accounting for known IPD risk factors. Secondary analyses categorized opioid use by opioid characteristics, applied an IPD risk score to assure comparability between exposure groups, and analyzed pneumonia and nonpneumonia IPD cases separately.

RESULTS

Persons in the case group had greater odds than control participants of being current opioid users (adjusted odds ratio [aOR], 1.62 [95% CI, 1.36 to 1.92]). Associations were strongest for opioids that were long acting (aOR, 1.87 [CI, 1.24 to 2.82]), of high potency (aOR, 1.72 [CI, 1.32 to 2.25]), or were used at high dosages (50 to 90 morphine milligram equivalents [MME]/d: aOR, 1.71 [CI, 1.22 to 2.39]; ≥90 MME/d: aOR, 1.75 [CI, 1.33 to 2.29]). Results were consistent when the IPD risk score was taken into account and pneumonia and nonpneumonia IPD were analyzed separately.

LIMITATIONS

Unmeasured confounding and measurement error, although sensitivity analyses suggested that neither was likely to affect results. Actual opioid use and other nonprescription use (such as illicit opioid use) were not measured.

CONCLUSION

Opioid use is associated with an increased risk for IPD and represents a novel risk factor for these diseases.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Opioids and cancer: friend or foe?

PURPOSE OF REVIEW

Most cancer patients experience pain and many will require opioids. However, the effects of opioids on cancer progression, metastasis, and recurrence is increasingly being questioned. There is evidence that opioids affect immune system function, angiogenesis, apoptosis, and invasion in a potentially deleterious manner. This review will examine the preclinical and clinical evidence.

RECENT FINDINGS

Recent clinical data have struggled to find robust evidence that opioids promote cancer progression. Although most study has involved morphine, differential effects of other opioids on immune function and cancer are revealing a more complex picture.

SUMMARY

Although there is a biologically plausible story, evidence for the action of opioids on cancer is mixed. Indeed, it may even be that in the chronic setting morphine has a beneficial effect on outcome in certain cancer types. This review critically examines and evaluates the evidence for the action of opioids on the processes involved in cancer progression. In the light of the uncertainty of opioid effect on cancer, any decision making should be tempered by knowing that stress and pain undoubtedly contribute to cancer progression.

In contrast to morphine, buprenorphine enhances macrophage-induced humoral immunity and, as oxycodone, slightly suppresses the effector phase of cell-mediated immune response in mice

BACKGROUND

Opioid receptors are commonly expressed on various immune cells, macrophages especially. Thus, these cells are prone to stimulation with opioids, which seems to be responsible for opioid-induced immunomodulatory effects. While morphine, fentanyl and methadone influence on mouse immune response was recently studied, little is known about the potential immunomodulatory impact of buprenorphine and oxycodone.

AIM

The current research aimed to investigate the influence of buprenorphine and oxycodone on immune responses in mice under homeostatic conditions.

METHODS AND RESULTS

Repeated administration of morphine led to intensification of CHS response in actively sensitized mice, while buprenorphine or oxycodone administration exerted the opposite effect. Further, hapten-conjugated macrophages from mice treated with morphine, when transferred into naive recipients, induced more potent CHS response. The enhanced generation of reactive oxygen intermediates and nitric oxide by macrophages from mice treated with buprenorphine, oxycodone or morphine was also shown, along with increased release of IL-6, TNFα and TGFβ. Treatment with opioids altered expression of antigen phagocytosis and presentation markers. Finally, the inhibitory effect of morphine treatment on induction of humoral immunity by macrophages was demonstrated, while oxycodone failed to influence humoral immune response and buprenorphine actually enhanced B-cell activation.

CONCLUSIONS

Current observations confirm that macrophages greatly contribute to immunomodulatory effects of opioids. Studies on immunomodulation by opioids have great importance related to the evaluation of its beneficial and adverse effects on patient condition. Our research showed that oxycodone exerts the weakest immunomodulatory properties, allowing us to assume this drug as safer than morphine during prolonged therapy.

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.

Intravenous drug abuse is a risk factor in the failure of two-stage treatment for infected total hip arthroplasty

Reinfection after two-stage revision hip arthroplasty (RHA) is still a complex issue. Only few studies revealed the factors affecting the success rate in the treatment of periprosthetic hip infection (PHI), especially risk factors. A retrospective study was conducted using records of 30 patients underwent two-stage RHA for infected total hip arthroplasty (THA). Treatment was defined as successful if a patient did not need any reoperation or invasive procedure such as image-guided drainage during the two years after reimplantation. Treatment was defined as failure if any surgery or invasive procedure or long-term antibiotic suppression was considered necessary to control infection. Four patients had infection recurrence defined as failed and three of them had intravenous drug abuse. Twenty-six patients had no infection recurrence at the end of follow-up and one of them had intravenous drug abuse but quitting after surgery. We suggest that once adequate cleaning up achieved, risk of reinfection may be little even in immunocompromised patients with RHA because of relative less old age than those with revisional total knee arthroplasty. Patients of the reinfection group were younger and non-obese with adequate nutritional status. We may consider intravenous drug abuse could take a great toll on health and lead to reinfection. Finally, we suggest performing the gold-standard two-stage reimplantation technique to manage cases with infection, educating drug abusers regarding the risk of surgical failure, and implementing a quitting program at least 1 year before the index surgery.

Features of Postoperative Immune Suppression Are Reversible With Interferon Gamma and Independent of Interleukin-6 Pathways

OBJECTIVE

The aim of this study was to evaluate the role of interleukin (IL)-6 pathways in postoperative immune suppression and to assess the reversibility of this phenomenon.

BACKGROUND

The postoperative period is characterized by increased IL-6 production and features of immune suppression. In vitro, IL-6 mediates anti-inflammatory effects through inhibition of interferon gamma (IFN-γ) pathways. The significance of the immunomodulatory effects of IL-6 in the clinical setting of postoperative immune suppression remains unclear.

METHODS

Patients over 45 years old undergoing elective surgery, involving the gastrointestinal tract, were recruited. IL-6 levels were assayed using an enzyme linked immunosorbent assay preoperatively, and at 24 and 48 hours. Peripheral blood mononuclear cells from healthy volunteers were cultured in perioperative serum and CD14Human Leukocyte Antigen-DR (HLA-DR) [monocyte HLA-DR (mHLA-DR)] geometric mean florescent intensity was measured in the presence and absence of IL-6 neutralizing antibody and recombinant IFN-γ.

RESULTS

Of the 108 patients, 41 developed a postoperative infection. The IL-6 levels increased 19-fold from the preoperative sample to 24 hours postoperatively (P < 0.0001). Higher IL-6 levels at 24 (P = 0.0002) and 48 hours (P = 0.003) were associated with subsequent postoperative infectious complications. mHLA-DR mean florescent intensity fell when healthy peripheral blood mononuclear cells were cultured with postoperative serum compared with preoperative serum (P = 0.008). This decrease was prevented by the presence of IFN-γ in the culture media, but not by the presence of IL-6-neutralizing antibody.

CONCLUSIONS

IL-6 levels increase after a major surgery and are associated with an increased susceptibility to postoperative infections. Serum obtained from postoperative patients induces an immunosuppressive response, reflected in reduced mHLA-DR levels, mediated through IL-6 independent pathways and is reversible with IFN-γ. These data may have therapeutic implications for the prevention of infection in patients undergoing major surgery.

Opioids increase hip fracture risk: a meta-analysis

The relationship between hip fracture risk and opioid use remains controversial. Thus, we performed a meta-analysis to assess the risk of hip fracture among opioid users. PubMed and EMBASE were searched for studies published from the inception of the databases until June 2015. The information was extracted independently by two teams of authors. When the heterogeneity was significant, the random-effects model was used to calculate the overall pooled risk estimates. Ten studies with 697,011 patients were included in the final meta-analysis. The overall combined relative risk for the use of opioids and hip fracture was 1.54 [95 % confidence interval (CI) 1.34-1.77]. Subgroup analyses revealed sources of heterogeneity, and sensitivity analysis indicated stable results, and no publication bias was observed. This meta-analysis demonstrates that opioids significantly increase the risk of hip fracture.

Hormonal systems, human social bonding, and affiliation

Which hormones are implicated in human social bonding and affiliation? And how does field research speak to this issue? We begin by laying out a broad view of how endocrine hormones in general modulate life history allocations of energy and other resources, and the ways in which their neuromodulatory functions must be understood within a broader conceptualization of how they have been shaped to affect allocations. We then turn to four specific hormones or hormone families that have received much attention: oxytocin, opioids, prolactin, and progesterone. Each plays a role in regulating psychological capacities and propensities that underlie individuals' interactions with important social targets. Yet in no case is it clear exactly what regulatory roles these hormones play. We suggest several directions for future research.

New Cancer Pain Treatment Options

PURPOSE OF REVIEW

Cancer pain is often incapacitating and discouraging to patients; is demoralizing to family members and care takers; and is taxing and difficult to subdue for the pain specialists. The consequences of implementing suboptimal treatment are far-reaching; therefore, effective treatment methods are in a great demand. The face of cancer pain management has changed in considerable ways, and interventional procedures have become an integral part of providing multimodal analgesia in cancer pain treatment. The goals of this review are to draw attention to the critical role that regional anesthetic nerve blocks and interventional pain management techniques play in treating malignancy-related pain and emphasize the benefits provided by the aforementioned treatment strategies.

RECENT FINDINGS

A large proportion of cancer patients continues to struggle with an inadequately treated pain despite a strict adherence to the WHO analgesic step ladder. The previous pain treatment algorithm has been modified to include peripheral neural blockade, neuro-destructive techniques, neuromodulatory device use, and intrathecal drug delivery systems. The accumulated evidence highlights the opioid-sparing qualities and other benefits afforded by these modalities: decreasing medication-induced side effects, reducing economic burden of poor analgesia, and overall improvement in quality of life of the patients afflicted with a painful neoplastic disease. The rising prevalence of cancer-related pain syndromes is paralleled by an unmatched growth of innovative treatment strategies. Modified WHO analgesic ladder represents one of the greatest paradigm shifts within the domain of oncologic pain treatment. The cancer patient population requires a prompt and liberal, albeit judicious, delivery of unorthodox pain treatment options freed from the rigid bonds of conventional guidelines and standard practices.

The Neurostimulation Appropriateness Consensus Committee (NACC) Recommendations for Infection Prevention and Management

INTRODUCTION

The use of neurostimulation for pain has been an established therapy for many decades and is a major tool in the arsenal to treat neuropathic pain syndromes. Level I evidence has recently been presented to substantiate the therapy, but this is balanced against the risk of complications of an interventional technique.

METHODS

The Neurostimulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society convened an international panel of well published and diverse physicians to examine the best practices for infection mitigation and management in patients undergoing neurostimulation. The NACC recommendations are based on evidence scoring and peer-reviewed literature. Where evidence is lacking the panel added expert opinion to establish recommendations.

RESULTS

The NACC has made recommendations to improve care by reducing infection and managing this complication when it occurs. These evidence-based recommendations should be considered best practices in the clinical implantation of neurostimulation devices.

CONCLUSION

Adhering to established standards can improve patient care and reduce the morbidity and mortality of infectious complications in patients receiving neurostimulation.