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

Morphine self-administration decreases intrinsic excitability of accumbal medium spiny neurons and suppresses the innate immune system in male Wistar rats

INTRODUCTION

Morphine alleviates severe pain but is addictive and associated with weakened immune system. Interestingly, the immunosuppressive effects have been linked to central circuits including the nucleus accumbens shell (NAc), suggesting that there might be a direct link between reward processing in the NAc and weakened immune system. The overall aim with this study was to assess the impact displayed by morphine self-administration on neuroplasticity in the NAc shell and circulating white blood cells.

METHODS

Wistar rats received morphine injections over ten days, and locomotor activity was monitored. Next, morphine self-administration, and relapse drinking after forced abstinence, were assessed. Lastly, electrophysiological recordings were conducted in the NAc ex vivo to define neurophysiological adaptations, and hematological analysis were conducted in parallel.

RESULTS

While ten days of morphine injections were not sufficient to affect morphine self-administration, behavioral sensitization to the locomotor stimulatory properties of morphine was observed and further correlated with the amount of morphine consumed following forced abstinence. Electrophysiological slice recordings demonstrated no effect on excitatory neurotransmission, but the intrinsic excitability of NAc neurons was significantly depressed compared to water drinking controls. In addition, hematological analysis demonstrated a significant decline in the number of white blood cells, especially monocytes and neutrophils, while erythrocytes were not affected. The amount of circulating white blood cells further correlated with morphine intake, but not with neurophysiological parameters.

CONCLUSION

The data presented here demonstrates that morphine self-administration produces accumbal neuroplasticity and biological transformations that could contribute to the addictive and immunosuppressive properties of morphine.

Perioperative risk factors for prognosis in patients undergoing radical esophagectomy: A retrospective study

BACKGROUND

Esophageal cancer constitutes one of the most aggressive malignant neoplasms associated with poor clinical outcomes. While surgical resection remains the cornerstone of curative intervention, optimization of perioperative care protocols has emerged as an essential strategy to reduce postoperative complications and potentially improve long-term survival rates in patients undergoing esophagectomy. However, substantial debate persists regarding the relative importance of various perioperative risk factors and their impact on post-resection outcomes.

AIM

To identify perioperative factors affecting prognosis after radical esophagectomy, aiming to improve patient outcomes through targeted interventions.

METHODS

A retrospective study analyzed 378 patients with esophageal cancer who underwent radical esophagectomy (McKeown, Sweet, or Ivor-Lewis procedures) from January 2022 through December 2023. All operations were performed by experienced surgeons following standardized perioperative protocols. The investigation gathered data on patient demographics, surgical parameters, tumor pathology (using the 8th edition American Joint Committee on Cancer staging system), and survival outcomes. Statistical analyses utilized Kaplan-Meier estimates and Cox proportional hazards modeling, with adjustment for confounding variables.

RESULTS

Multivariate Cox proportional hazards analysis identified three independent predictors of survival: Tumor-node-metastasis staging [Hazard ratio (HR) = 2.31, 95% confidence interval (CI): 1.72-3.10, P < 0.001], tumor differentiation (moderate: HR = 1.46, 95%CI: 1.02-2.09, P = 0.038; poor: HR = 2.15, 95%CI: 1.47-3.14, P < 0.001), and extended postoperative analgesic use (> 5 days) (HR = 1.43, 95%CI: 1.08-1.89, P = 0.012). Kaplan-Meier analysis demonstrated significantly lower overall survival rates in patients requiring analgesics for > 5 days compared to ≤ 5 days (P = 0.003), with consistent patterns observed for both opioid (P = 0.019) and nonsteroidal anti-inflammatory drug use (P = 0.028). The extended analgesic group exhibited a higher proportion of elderly patients (48.47% vs 35.57%, P = 0.015), while other baseline characteristics and tumor features remained comparable between groups.

CONCLUSION

Tumor-node-metastasis staging, tumor differentiation, and duration of postoperative analgesic use independently predict survival following radical esophagectomy, underscoring the significance of optimal pain management protocols.

Effects of Nefopam on Postoperative Analgesia in Operating Room-Extubated Patients Undergoing Living Donor Liver Transplantation: A Propensity Score-Matched Analysis

In patients undergoing living donor liver transplantation (LDLT) with immediate postoperative extubation in the operating room (OR), rapid recovery of consciousness and spontaneous ventilation are essential, requiring effective analgesia without compromising respiratory function. This study evaluated whether intraoperative nefopam administration improves early postoperative pain control and reduces opioid consumption in this physiologically distinct population. A retrospective cohort of 376 adult LDLT recipients who met the criteria for OR extubation was analyzed. After propensity score matching, 182 patients who received intraoperative nefopam were compared with 182 matched controls. Pain intensity was measured using the visual analog scale (VAS), and total fentanyl consumption and opioid-related complications were recorded over the first 24 h postoperatively. Nefopam administration was associated with significantly lower VAS scores during the first 12 h after surgery (p < 0.001) and reduced 24 h fentanyl consumption (53.2 ± 20.8 mL vs. 58.6 ± 27.5 mL, p = 0.035). No serious adverse effects related to nefopam were observed. The incidence of postoperative nausea and vomiting did not differ significantly between the groups. These findings indicate that nefopam offers effective early analgesia and an opioid-sparing effect in LDLT recipients undergoing OR extubation, suggesting its clinical utility as a component of multimodal analgesia in this high-risk group. Although the reduction in opioid use did not translate into a decreased incidence of opioid-related complications, the favorable safety profile and analgesic efficacy of nefopam support further investigation through prospective trials to define its role in enhanced recovery protocols for OR-extubated LDLT recipients.

Risk Factors for Infective Endocarditis and Serious Injection Related Infections Among People Who Inject Drugs in Los Angeles, CA and Denver, CO

BACKGROUND

Injection drug use-related infective endocarditis (IDU-IE) and bacterial infections have grown in the United States, but little is known about risk factors for these infections in community samples of people who inject drugs (PWID).

METHODS

During 2021-22, PWID were recruited from community settings and surveyed for history of IDU-IE, serious injection related symptoms (SIRI) and untreated infection symptoms in the last 3 months. We used bivariate analysis and multiple logistic regression to examine factors associated with these outcomes.

RESULTS

Among participants (n = 472), 7 % reported ever having IDU-IE, 14 % reported having SIRI symptoms and 20 % reported untreated infection symptoms in the last 3 months. Ever having IDU-IE was associated with HCV (adjusted odds ratio [AOR]=8.37; 95 % confidence interval [CI]=2.46, 28.49), prior MRSA infection (AOR=5.37; 95 % CI=2.44, 11.80), identifying as female and/or gender minority person (AOR=3.14; 95 % CI=1.42, 6.95). SIRI symptoms were associated with greater material hardship (compared to low; AOR=2.47; 95 % CI=1.17, 5.22), fentanyl use (AOR=2.15; 95 % CI=1.01, 4.61), sharing filter/cotton (AOR=1.93; 95 % CI=1.10, 3.39), and licking needle prior to injection (AOR=1.85; 95 % CI=1.02, 3.36). Untreated infection symptoms were associated with poor quality sleep (AOR=2.04; 95 % CI=1.21, 3.43), any mental health diagnoses (AOR=2.01; 95 % CI=3.56), any chronic pain (AOR=1.89; 95 % CI=1.14, 3.11), sharing filters (AOR=1.81; 95 % CI=1.10, 2.98), and prior MRSA infection (AOR=1.75; 95 % CI=1.04, 2.97).

CONCLUSION

Risk factors identified include treatable co-morbidities (i.e., HCV & MRSA history, mental health, pain, opioid use), modifiable health behaviors (i.e., equipment sharing, needle-licking), and addressable structural conditions (material hardship, housing).

The effect of general versus spinal anesthesia on perioperative innate immune function in patients undergoing total hip arthroplasty

BACKGROUND

Increasing evidence shows that postoperative innate immune dysregulation is associated with delayed recovery and infectious complications. The aim of this study was to compare the effects of general versus spinal anesthesia on innate immune function during and after total hip arthroplasty (THA).

METHODS

This comparative matched cohort study used data from two single-center randomized-controlled trials. Patients from the control group of the HIPPO study received general anesthesia and were matched to control patients from the MAGIC study who received spinal anesthesia in a 2:1 ratio (general(n = 18); spinal(n = 9)). Immune function was assessed by determination of ex vivo cytokine production capacity upon whole blood stimulation with E. coli lipopolysaccharides (LPS) and measurement of plasma cytokines and danger-associated molecular patterns (DAMPs).

RESULTS

In the general anesthesia group, ex vivo cytokine production capacity of IL-1β was significantly lower shortly after induction (p = 0.02) and both IL-1β and IL-6 were significantly lower at the end of surgery compared to the spinal anesthesia group (p = 0.002 and p = 0.02, respectively). On postoperative day 1 (POD1), no differences were observed. Plasma cytokine concentrations did not differ between the spinal and general anesthesia group at most timepoints, except for IL-10 at the end of surgery (p = 0.04) and TNF on POD1 (p = 0.04), which were higher in the general anesthesia group. Plasma concentrations of DAMPs did not differ between the groups.

CONCLUSIONS

General anesthesia has a transient impact on innate immune function in patients undergoing THA, but the clinical significance of anesthesia-induced innate immune dysregulation might be limited as no differences were observed on POD1.

TRIAL REGISTRATION

The HIPPO study (NCT05562999, date of registration 2022-10-03) and MAGIC study (NCT05723406, date of registration 2023-02-10) are registered at ClinicalTrials.gov.

A retrospective examination of risk factors for central line-associated bloodstream infections in home parenteral nutrition patients from a Queensland tertiary hospital

BACKGROUND

Central line-associated bloodstream infections (CLABSIs) are a potential complication for home parenteral nutrition (HPN) patients.

AIM

We sought to analyse risk factors of developing HPN-related CLABSI and assess CLABSI management in the Australian context.

METHODS

A retrospective observational cohort study was conducted on 34 adult patients receiving HPN via a central venous catheter (CVC) at a Queensland tertiary referral centre between 2016 and 2023. Patient charts were reviewed, and Kaplan-Meier analysis was employed to determine associations between characteristics and time to CLABSI in the first CVC using Peto-Peto Prentice test.

RESULTS

A total of 39 CLABSI episodes occurred in 19 patients. Patients with ≥1 CLABSI used regular opioids more than those without CLABSI (P = 0.016). Fourteen (41%, n = 14/34) patients developed a CLABSI in their first CVC. No patient or line characteristics were found to be predictive of CLABSI in their first CVC. The CLABSI rate was 1.02/1000 catheter days. Most CLABSIs were caused by Enterobacterales (22%, n = 12/55) and Candida sp. (22%, n = 12/55). Empiric antimicrobial therapy was adequate in only 25% (n = 7/28), and the median time to effective antibiotic therapy was 22.7 h (interquartile range 4.8-29.8). There were three successful CVC salvages (8%, n = 3/39).

CONCLUSIONS

In this cohort of patients, regular opioid use was associated with increased risk of developing CLABSI. Based on our findings, an empiric antimicrobial regime of vancomycin, cefepime and caspofungin will provide adequate coverage for most HPN-related CLABSIs in Australian IF units with a similar antimicrobial distribution and resistance pattern.

Pharmacological Strategies to Decrease Long-Term Prescription Opioid Use: A Systematic Review

Background/Objectives: As long-term prescription opioid use is associated with increased morbidity and mortality, timely dose reduction of prescription opioids should be considered. However, most research has been conducted on patients using heroin. Given the differences between prescription and illicit opioid use, the aim of this review was to provide an overview of pharmacological strategies to reduce prescription opioid use or improve clinical outcomes for people who experience long-term prescription opioid use, including those with opioid use disorder. Methods: We conducted a systematic database search of PubMed, Embase, CINAHL, and the Cochrane Library. Outcomes included dose reduction, treatment dropout, pain, addiction, and outcomes relating to quality of life (depression, functioning, quality of life). Results: We identified thirteen studies (eight randomized controlled trials and five observational studies). Pharmacological strategies were categorized into two categories: (1) deprescribing (tapering) opioids or (2) opioid agonist treatment (OAT) with long-acting opioids. Tapering strategies decreased opioid dosage and had mixed effects on pain and addiction. OAT with buprenorphine or methadone led to improvements in pain relief and quality of life, with a slight (non-significant) preference for methadone in terms of treatment retention (RR = 1.10 [CI: 0.89-1.37]) but not for other outcomes. Most studies had high dropout rates and a serious risk of bias. Conclusions: Tapering reduced prescription opioid doses had mixed effects on pain. OAT improved clinical outcomes without dose reduction. Based on our review findings, there is no clear preference for either tapering or OAT. Tapering may be considered first as it reduces dependency, tolerance, and side effects, but is associated with adverse events and not always feasible. OAT can be a suitable alternative. Non-pharmacological interventions may facilitate tapering. Further research is needed to identify novel pharmacological strategies to facilitate opioid tapering. Registration: PROSPERO 2022 CRD42022323468.

Opioid-free strategies for patient-controlled intravenous postoperative analgesia: a review of recent studies

Postoperative pain management has consistently been a critical topic in the medical field, with patient-controlled intravenous analgesia (PCIA) being one of the most commonly utilized methods for postoperative analgesia. Currently, opioids remain the primary choice for PCIA in clinical practice. However, in recent years, an increasing number of studies have explored analgesic strategies aimed at reducing or eliminating the use of opioids in PCIA to mitigate the associated side effects and dependence. This article systematically reviews the progress of research on opioid-free analgesic strategies in PCIA through a comprehensive analysis of relevant literature.

Risk of infections among persons treated with opioids for chronic pain: a systematic review and meta-analysis protocol

INTRODUCTION

Millions of persons with chronic pain across North America and Europe use opioids. While the immunosuppressive properties of opioids are associated with risks of infections, these outcomes could be mitigated through careful patient selection and monitoring practices when appropriate. It is important to recognise that some patients do benefit from a carefully tailored opioid therapy. Enough primary studies have been published to date regarding the role of opioids in potential immunosuppression presenting as an increased rate of infection acquisition, infectious complications and mortality. There is thus a critical need for a consensus in this area.

METHODS AND ANALYSIS

The methodology is based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, the MOOSE Guidelines for Meta-Analyses and Systematic Reviews of Observational Studies and the Cochrane Handbook for Systematic Reviews of Interventions. We plan to systematically search Ovid MEDLINE, CINAHL, PsycINFO, EMB Review, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials and Google Scholar databases from their inception date to December 2023. Full-text primary studies that report measurable outcomes in adults with chronic pain, all routes of opioid use, all types of infections and all settings will be included. We will identify a scope of reported infections and the evidence on the association of opioid use (including specific opioid, dosage, formulation and duration of use) with the risk of negative infectious outcomes. Opioid use-associated outcomes, comparing opioid use with another opioid or a non-opioid medication, will be reported. The meta-analysis will incorporate individual risk factors. If data are insufficient, the results will be synthesised narratively. Publication bias and confounding evaluation will be performed. The Grading of Recommendations Assessment, Development and Evaluation framework will be used.

ETHICS AND DISSEMINATION

Approval for the use of published data is not required. The results will be published, presented at conferences and discussed in deliberative dialogue groups.

PROSPERO REGISTRATION NUMBER

CRD42023402812.

Fentanyl enhances immune cell response through TLR4/MD-2 complex

Introduction

Opioids have been shown to induce neuroinflammation and immune cell activation, that might contribute to some of the opioid side effects, such as opioid-induced tolerance and paradoxical hyperalgesia. In this context, TLR4/MD-2 complex has been proposed as an off-target site for opioid action. This study was aimed at investigating the effect of fentanyl on lipopolysaccharide (LPS)-induced TLR4/MD-2 activation in rat primary microglia and human monocyte-derived macrophages (MDM).

Materials and Methods

The effect of fentanyl was first explored by measuring the expression and release of different proinflammatory mediators in primary rat microglia and human MDM by real-time PCR and ELISA. Then, the involvement of TLR4/MD-2 signaling was investigated studying NF-κB activation in HEK293 cells stably transfected with human TLR4, MD-2, and CD14 genes (HEK-Blue hTLR4 cells) and in human MDM.

Results

Fentanyl increased mRNA levels, as well as the LPS-induced secretion of proinflammatory mediators in primary microglia and MDM. Two inhibitors of TLR4/MD-2 signaling, namely the oxazoline derivative of N-palmitoylethanolamine (PEA-OXA) and CLI-095, blocked the production and release of proinflammatory cytokines by microglia stimulated with LPS and fentanyl, suggesting that TLR4/MD-2 could be the target of the proinflammatory activity of fentanyl. Finally, we showed that fentanyl in combination with LPS activated NF-κB signaling in human MDM and in HEK-Blue hTLR4 cells and this effect was blocked by inhibitors of TLR4/MD-2 complex.

Discussion

These results provide new insight into the mechanism of the proinflammatory activity of fentanyl, which involves the activation of TLR4/MD-2 signaling. Our findings might facilitate the development of novel inhibitors of TLR4/MD-2 signaling to combine with opioid-based analgesics for effective and safe pain management.

Comparison of opioid-free and opioid-inclusive propofol anaesthesia for thyroid and parathyroid surgery: a randomised controlled trial

BACKGROUND

Postoperative nausea and vomiting occur frequently following thyroid and parathyroid surgery and are associated with worse patient outcomes. We hypothesised that opioid-free propofol anaesthesia would reduce the incidence of postoperative nausea and vomiting compared with opioid-inclusive propofol anaesthesia in patients undergoing these procedures.

METHODS

We conducted a randomised, double-blinded controlled trial in adult patients scheduled to undergo thyroid and parathyroid surgery at two medical centres in mainland China. Patients were allocated randomly (1:1, stratified by sex and trial site) to an opioid-free anaesthesia group (esketamine, lidocaine, dexmedetomidine and propofol) or an opioid-inclusive group (sufentanil and propofol). Propofol infusions were titrated to bispectral index 45-55. Patients received prophylaxis for nausea and vomiting using dexamethasone and ondansetron and multimodal analgesia with paracetamol and flurbiprofen axetil. The primary outcome was the incidence of postoperative nausea and vomiting in the first 48 h after surgery.

RESULTS

We assessed 557 patients for eligibility and 394 completed this trial. The incidence of postoperative nausea and vomiting in the first postoperative 48 h was lower in the opioid-free anaesthesia group (10/197, 5%) compared with opioid-inclusive group (47/197, 24%) (OR (95%CI) 0.17 (0.08-0.35), p < 0.001), yielding a number needed to treat of 5.3. Additionally, opioid-free propofol anaesthesia was associated with a reduced need for rescue anti-emetics, lower rates of hypotension and desaturation after tracheal extubation, and higher patient satisfaction. Time to tracheal extubation was prolonged slightly in the opioid-free group. The two groups had similar postoperative pain scores and 30-day outcomes.

DISCUSSION

Opioid-free propofol anaesthesia reduced postoperative nausea and vomiting in patients undergoing thyroid and parathyroid surgery. An opioid-free anaesthetic regimen can optimise anaesthetic care during thyroid and parathyroid surgery.

Fentanyl Overdose Causes Prolonged Cardiopulmonary Dysregulation in Male SKH1 Mice

Fentanyl overdose is a survivable condition that commonly resolves without chronic overt changes in phenotype. While the acute physiological effects of fentanyl overdose, such as opioid-induced respiratory depression (OIRD) and Wooden Chest Syndrome, represent immediate risks of lethality, little is known about longer-term systemic or organ-level impacts for survivors. In this study, we investigated the effects of a single, bolus fentanyl overdose on components of the cardiopulmonary system up to one week post. SKH1 mice were administered subcutaneous fentanyl at the highest non-lethal dose (62 mg/kg), LD10 (110 mg/kg), or LD50 (135 mg/kg), before euthanasia at 40 min, 6 h, 24 h, or 7 d post-exposure. The cerebral cortex, heart, lungs, and plasma were assayed using an immune monitoring 48-plex panel. The results showed significantly dysregulated cytokine, chemokine, and growth factor concentrations compared to time-matched controls, principally in hearts, then lungs and plasma to a lesser extent, for the length of the study, with the cortex largely unaffected. Major significant analytes contributing to variance included eotaxin-1, IL-33, and betacellulin, which were generally downregulated across time. The results of this study suggest that cardiopulmonary toxicity may persist from a single fentanyl overdose and have wide implications for the endurance of the expanding population of survivors.

Effects of opioid drugs on immune function in cancer patients

Opioid receptor agonists are often used when cancer patients undergo surgery or analgesic treatment. As analgesics in clinical care, opioids can provide intraoperative or to chronic cancer pain relief. Immune function plays an important role in anti-cancer therapy, with cellular immunity, comprised principally of T-lymphocytes and natural killer cells, representing the primary anti-cancer immune response. However, it remains unclear whether immune function is further affected with the use of opioids in already immunocompromised cancer patients. This article provides a review of the effects of commonly used clinical opioids, including morphine, oxycodone, fentanyl and tramadol, on immune function in cancer patients. It provides a summary of current evidence regarding the immunomodulatory effects of opioids in the cancer setting and mechanisms underlying these interactions.

Opioid analgesics for nociceptive cancer pain: A comprehensive review

Pain is one of the most burdensome symptoms in people with cancer, and opioid analgesics are considered the mainstay of cancer pain management. For this review, the authors evaluated the efficacy and toxicities of opioid analgesics compared with placebo, other opioids, nonopioid analgesics, and nonpharmacologic treatments for background cancer pain (continuous and relatively constant pain present at rest), and breakthrough cancer pain (transient exacerbation of pain despite stable and adequately controlled background pain). They found a paucity of placebo-controlled trials for background cancer pain, although tapentadol or codeine may be more efficacious than placebo (moderate-certainty to low-certainty evidence). Nonsteroidal anti-inflammatory drugs including aspirin, piroxicam, diclofenac, ketorolac, and the antidepressant medicine imipramine, may be at least as efficacious as opioids for moderate-to-severe background cancer pain. For breakthrough cancer pain, oral transmucosal, buccal, sublingual, or intranasal fentanyl preparations were identified as more efficacious than placebo but were more commonly associated with toxicities, including constipation and nausea. Despite being recommended worldwide for the treatment of cancer pain, morphine was generally not superior to other opioids, nor did it have a more favorable toxicity profile. The interpretation of study results, however, was complicated by the heterogeneity in the study populations evaluated. Given the limited quality and quantity of research, there is a need to reappraise the clinical utility of opioids in people with cancer pain, particularly those who are not at the end of life, and to further explore the effects of opioids on immune system function and quality of life in these individuals.

A novel investigation into the negative impact of opioid use on the efficacy of immune checkpoint inhibitors in advanced non-small cell lung cancer patients

OBJECTIVE

Immune checkpoint inhibitors (ICIs) have effectively improved the clinical outcome of advanced non-small cell lung cancer (NSCLC). Opioids are commonly used for pain relief in cancer patients. This study aims to clarify the prognostic impact of opioid use in advanced NSCLC patients receiving ICI therapy.

METHODS

A systematic literature review was carried out using online databases before July 2023. The meta-analysis was used to clarify the correlation of opioid use with the overall survival (OS) or progression-free survival (PFS) of ICI-treated NSCLC patients, both of which were determined using hazard ratios (HRs) coupled with 95 % confidence intervals (CIs). Then, an independent cohort enrolling 181 NSCLC patients was utilized for validation. Finally, a comprehensive bioinformatics analysis based on TCGA cohort was performed to investigate the prognostic significance of opioid target genes (OTGs) and their correlation with immune infiltration in NSCLC patients.

RESULTS

A total of 8 studies enrolling 1174 patients were included in the meta-analysis. Opioid use was negatively associated with worse PFS (HR = 2.16, 95 %CI: 1.26-3.71) and OS (HR = 2.02, 95 %CI: 1.54-2.63) in ICI-treated NSCLC patients. The retrospective validation confirmed the above result and identified opioid use as an independent unfavorable predictor for PFS and OS in both the entire cohort and ICI subgroup. The bioinformatic analysis identified 14 prognostic OTGs (CYP17A1, PDYN, PYCARD, FGA, NTSR1, FABP1, HPCA, PENK, PDGFB, LIN7A, FKBP5, TYMS, CACNA1H and LDHA), most of which were correlated with immune infiltration in NSCLC. A risk model was constructed based on 14 OTGs and found to effectively stratify the clinical outcome in both the training and validation set, independent of age, gender and TNM staging system. The model was also significantly correlated with infiltration of activated dendritic cells, neutrophils and tumor infiltrating lymphocytes. Finally, a nomogram was constructed based on the model, age, gender and TNM stage, which could predict well the 1-, 3- and 5-year survival of NSCLC patients.

CONCLUSION

Opioid use is correlated with the poor clinical outcome in ICI-treated NSCLC patients. Precise pain management is highly advocated and opioids are recommended to be cautiously used in these patients. OTGs have the potential to be prognostic biomarkers for NSCLC patients and their role in tumor immunity needs to be further investigated.

Non-Neuraxial Chest and Abdominal Wall Regional Anesthesia for Intensive Care Physicians-A Narrative Review

Multi-modal analgesic strategies, including regional anesthesia techniques, have been shown to contribute to a reduction in the use of opioids and associated side effects in the perioperative setting. Consequently, those so-called multi-modal approaches are recommended and have become the state of the art in perioperative medicine. In the majority of intensive care units (ICUs), however, mono-modal opioid-based analgesic strategies are still the standard of care. The evidence guiding the application of regional anesthesia in the ICU is scarce because possible complications, especially associated with neuraxial regional anesthesia techniques, are often feared in critically ill patients. However, chest and abdominal wall analgesia in particular is often insufficiently treated by opioid-based analgesic regimes. This review summarizes the available evidence and gives recommendations for peripheral regional analgesia approaches as valuable complements in the repertoire of intensive care physicians' analgesic portfolios.

Immunomodulation by tramadol combined with acetaminophen or dexketoprofen: In vivo animal study

Among other functions, macrophages remove foreign particles, including medications, from the circulation, making them an important target for immunomodulatory molecules. Currently, growing evidence suggests that analgesics affect the activity of immune cells not directly related to pain, and thus may induce unwanted immunosuppression in patients at risk. However, the immunomodulatory effects resulting from macrophage targeting by these drugs are understudied. Therefore, the current study investigated the immune effects induced in healthy mice by repeated administration of tramadol alone or in combination with acetaminophen or dexketoprofen. We observed that drug administration decreased the percentage of infiltrating macrophages in favor of resident macrophages in peritoneal exudates. While all drugs reduced the number of infiltrating macrophages that phagocytosed sheep red blood cells (SRBC), their administration increased the effectiveness of phagocytosis, and treatment with acetaminophen with or without tramadol elevated the expression of MHC class II by Mac3+ macrophages. Interestingly, SRBC-pulsed macrophages from mice treated with tramadol combined with acetaminophen potently activated SRBC-specific B cells in humoral response, and administration of these drugs to recipients of contact hypersensitivity effector cells augmented the resulting cellular immune response. In addition, tramadol administered alone or with dexketoprofen enhanced the spontaneous release of pro-inflammatory cytokines by macrophages. Our current research findings demonstrate that tramadol therapy in combination with acetaminophen or dexketoprofen has a relatively low risk of causing immunosuppressive side effect because the drugs slightly reduce the inflammatory reaction of macrophages but do not impair their ability to activate the adaptive immune responses.

Immunoception: the insular cortex perspective

To define the systemic neuroimmune interactions in health and disease, we recently suggested immunoception as a term that refers to the existence of bidirectional functional loops between the brain and the immune system. This concept suggests that the brain constantly monitors changes in immune activity and, in turn, can regulate the immune system to generate a physiologically synchronized response. Therefore, the brain has to represent information regarding the state of the immune system, which can occure in multiple ways. One such representation is an immunengram, a trace that is partially stored by neurons and partially by the local tissue. This review will discuss our current understanding of immunoception and immunengrams, focusing on their manifestation in a specific brain region, the insular cortex (IC).

Bibliometric Analysis of Anesthetic Drugs' Effects on Immune Function- Current Knowledge, Hotspots and Future Perspectives

Objective

The objective of this study is to conduct a bibliometric analysis of the present status, areas of focus, and upcoming developments in the research of anesthetic drugs and their impact on immune function, along with other related research domains.

Methods

From January 1, 2008 to June 9, 2023, A thorough exploration of anesthetic drug-related literature pertaining to immune function was carried out through the utilization of the Web of Science. The bibliometric analysis was predominantly executed by means of CiteSpace, GraphPad Prism 8.0, and the acquisition of data regarding the country, institution, author, journal, and keywords associated with each publication.

Results

This study analyzed a comprehensive total of 318 publications, consisting of 228 articles and 90 reviews, to determine the publication output of anesthetic drugs on immune function. Notably, China exhibited the highest publication output with (109, 34.28%) articles. Among the institutions analyzed, Harvard University was found to be the most productive with (12, 3.77%) publications. The study findings indicate that Buggy, Donal J (5, 1.57%) and Yuki, Koichi (5, 1.57%) had the highest publication records. Anesthesiology was the most frequently cited journal with a total of (206) citations. The results also revealed that "surgery" was the most frequently used keyword, appearing (48 times), followed by "general anesthesia" (41 times) and "breast cancer" (37 times). The study has identified several current areas of interest, with a particular emphasis on "metastasis", "inflammation", "recurrence", "anesthesia technique", and "induction". It is anticipated that forthcoming research endeavors will concentrate on exploring the impacts of isoflurane, sevoflurane, and ketamine on immune function.

Conclusion

This study provided a thorough analysis of the research trends and developments in investigating the impact of anesthetic drugs on immune function, incorporating pertinent research and collaborative entities such as authors, institutions, and countries.

Preoperative Epidural Steroid Injections and Postoperative Infections After Lumbar or Cervical Spine Surgery: A Systematic Review and Meta-Analysis

Objective

To determine the risk difference and 95% prediction intervals (PIs) for postoperative infections (POIs) associated with preoperative epidural steroid injections (ESIs) in adults undergoing lumbar or cervical spine surgery.

Methods

Comprehensive database searches were conducted from inception dates through December 2023. Inclusion criteria included all study designs involving adults receiving a preoperative ESI before lumbar or cervical decompression or fusion spine surgery. Risk of bias was assessed using a modified tool developed for uncontrolled studies. The summary estimates of risk difference and the corresponding PIs were reported.

Results

A total of 12 studies were included in the systematic review, of which 9 were included in the meta-analysis. Preoperative ESIs within 1 month of lumbar spine decompression or fusion surgery were associated with a 0.6% and 2.31% greater risk of a POI, respectively. In adults ≥65 years of age, ESIs within 1 or 1-3 months of lumbar spine decompression or fusion surgery were associated with a 1.3% and 0.6% greater risk of a POI, respectively. Preoperative ESIs within 3 months of cervical spine fusion were not associated with an increased risk of a POI. The bounds of all corresponding 95% PIs were nonsignificant.

Conclusion

The observations of this study provide summary estimates of risk difference and 95% PIs, which could be used to support shared decision-making about the use of ESIs before cervical or lumbar spine surgery.