Effects of anesthesia based on large versus small doses of fentanyl on natural killer cell cytotoxicity in the perioperative period

Paravertebral block's effect on analgesia and inflammation in advanced gastric cancer patients undergoing transarterial chemoembolization and microwave ablation

BACKGROUND

Transarterial chemoembolization (TACE) combined with microwave ablation (MWA) is an effective treatment strategy for patients with advanced gastric cancer and liver metastasis. However, it may cause severe postoperative pain and inflammatory responses. The paravertebral block (PVB) is a regional anesthetic technique that provides analgesia to the thoracic and abdominal regions.

AIM

To evaluate the effect of PVB on postoperative analgesia and inflammatory response in patients undergoing TACE combined with MWA for advanced gastric cancer and liver metastasis.

METHODS

Sixty patients were randomly divided into PVB and control groups. The PVB group received ultrasound-guided PVB with 0.375% ropivacaine preoperatively, whereas the control group received intravenous analgesia with sufentanil. The primary outcome was the visual analog scale (VAS) score for pain at 6 h, 12 h, 24 h, and 48 h after the procedure. Secondary outcomes were the dose of sufentanil used, incidence of adverse events, and levels of inflammatory markers (white blood cell count, neutrophil percentage, C-reactive protein, and procalcitonin) before and after the procedure.

RESULTS

The PVB group had significantly lower VAS scores at 6 h, 12 h, 24 h, and 48 h after the procedure compared with the control group (P < 0.05). The PVB group also had a significantly lower consumption of sufentanil and a lower incidence of nausea, vomiting, and respiratory depression than did the control group (P < 0.05). Compared with the control group, the PVB group had significantly lower levels of inflammatory markers 24 h and 48 h after the procedure (P < 0.05).

CONCLUSION

PVB can effectively reduce postoperative pain and inflammatory responses and improve postoperative comfort and recovery in patients with advanced gastric cancer and liver metastasis treated with TACE combined with MWA.

Increased LPS-Induced Fever and Sickness Behavior in Adult Male and Female Rats Perinatally Exposed to Morphine

As a result of the current opioid crisis, the rate of children born exposed to opioids has skyrocketed. Later in life, these children have an increased risk for hospitalization and infection, raising concerns about potential immunocompromise, as is common with chronic opioid use. Opioids can act directly on immune cells or indirectly via the central nervous system to decrease immune system activity, leading to increased susceptibility, morbidity, and mortality to infection. However, it is currently unknown how perinatal opioid exposure (POE) alters immune function. Using a clinically relevant and translatable model of POE, we have investigated how baseline immune function and the reaction to an immune stimulator, lipopolysaccharide, is influenced by in utero opioid exposure in adult male and female rats. We report here that POE potentiates the febrile and neuroinflammatory response to lipopolysaccharide, likely as a consequence of suppressed immune function at baseline (including reduced antibody production). This suggests that POE increases susceptibility to infection by manipulating immune system development, consistent with the clinical literature. Investigation of the mechanisms whereby POE increases susceptibility to pathogens is critical for the development of potential interventions for immunosuppressed children exposed to opioids in utero.

Perioperative lidocaine and dexmedetomidine intravenous infusion reduce the serum levels of NETs and biomarkers of tumor metastasis in lung cancer patients: A prospective, single-center, double-blinded, randomized clinical trial

Background

Neutrophil extracellular traps (NETs) can enhance the metastasis of non-small cell lung cancer (NSCLC). As biomarkers of tumor metastasis, metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) together with NETs are essential to endothelial-to-mesenchymal transition (EMT). We hypothesized that intravenous infusion of lidocaine and dexmedetomidine could reduce the production of NETs and biomarkers of tumor metastasis after video-assisted thoracic surgery (VATS) in NSCLC patients.

Method

The trial included 132 NSCLC patients undergoing VATS. The patients were equally randomized to a placebo group (Group C), a lidocaine group (Group L, intravenous lidocaine 8 mg/kg/h for 15 minutes before anesthesia, 2 mg/kg/h during surgery, and 1 mg/kg/h until 24 hours after surgery), a dexmedetomidine group (Group D, intravenous dexmedetomidine 2 μg/kg/h for 15 minutes before anesthesia, 0.5 μg/kg/h during surgery, and 0.25 μg/kg/h until 24 hours after surgery), and a dexmedetomidine plus lidocaine group (Group LD, combination use of lidocaine and dexmedetomidine). The primary outcome was the production of myeloperoxidase (MPO) and citrullinated histone-3 (H3Cit), biomarkers of NETs, on postoperative day (POD) 1. MMP-3, MMP-9, and VEGF-α, as biomarkers of tumor metastasis, were also evaluated on POD 1.

Results

The baseline patient characteristics and perioperative data did not differ between the study groups. MPO was significantly decreased in Groups L, D, and LD (-197.08 ± 34.01, -137.37 ± 32.41, and -189.45 ± 33.73 U/ml, P<0.001, respectively) compared with Group C (-106.51 ± 25.44 U/ml). H3Cit was also lessened in Groups L, D, and LD (-49.51 ± 9.11, -34.80 ± 10.37, and -51.82 ± 8.98 ng/ml, P<0.001, respectively) compared with Group C (-24.73 ± 7.65 ng/ml). Lidocaine and dexmedetomidine also reduced MMP-3 (-69.08 ± 13.22, -52.84 ± 13.78, -85.34 ± 12.59 vs. -40.55 ± 10.71 ng/ml in Group L, D, LD vs. Group C, P<0.001, respectively), MMP-9 (-8.46 ± 1.68, -6.07 ± 1.82, -9.67 ± 1.43 vs. -4.28 ± 1.29 ng/ml in Group L, D, LD vs. Group C, P<0.001, respectively), and VEGF-α (-95.55 ± 22.53, -71.65 ± 18.77, -104.89 ± 15.49 vs. -51.73 ± 16.27 pg/ml in Group L, D, LD vs. Group C, P<0.001, respectively) on POD 1.

Conclusion

In NSCLC patients, continuous perioperative intravenous infusion of lidocaine and dexmedetomidine significantly reduced the production of NETs and tumor metastasis biomarkers on POD 1. Meanwhile, it also decreased inflammation, protected cellular immune function, reduced pain and opioid consumption, and improved the quality of postoperative recovery.

Clinical trial registration

chictr.org.cn, identifier: 187049.

Knowledge Mapping of Opioids and Immunomodulation: A Bibliometric Analysis (2000-2022)

Background

Increasing evidence indicates that opioids markedly affect the immune system. However, there are few studies on opioids and immunomodulation using bibliometric analysis.

Purpose

We aimed to provide a comprehensive overview of the research status and trends of the influence of opioids on immunomodulation using a bibliometric approach.

Methods

Articles related to opioids and immunomodulation published from 2000 to 2022 were obtained from the Science Citation Index Expanded of the Web of Science Core Collection by searching keywords related to opioids and immunomodulation. Bibliometric analyses and visualizations were conducted using the CiteSpace and VOSviewer software programs.

Results

From 2000 to 2022, a total of 3242 research articles on opioids and immunomodulation were published in 1126 academic journals by 16,555 authors in 3368 institutions from 102 countries/regions. A majority of publications were from the US and China, and the University of Minnesota System and Chinese Academy of Sciences were the most active institutions. Tsong-long Hwang had published the most papers, while Sabita Roy had the most cocitations. The Journal of Ethnopharmacology published the most papers on opioids and immunomodulation, the Journal of Immunology was the top cocited journal, and the major area of these publications were molecular, biological, and genetic. The top three keywords were "expression", "activation", and "inflammation."

Conclusion

The number of studies on opioids and immunomodulation has increased sharply all over the world in the last two decades. This is the first bibliometric study to comprehensively summarize the collaboration network in this field. It will help scholars to understand not only the basic knowledge structure but also potential collaborations, research trend topics, and hot directions.

The impact of spinal anaesthesia on perioperative opioid consumption, postoperative pain and oncological outcome in radical retropubic prostatectomy-a retrospective before-and-after effectiveness study

Background

Spinal anaesthesia preceding general anaesthesia has been conducted for open radical retropubic prostatectomy (RRP) to decrease immediate postoperative pain for many years. Nevertheless, the effectiveness of spinal anaesthesia to reduce postoperative opioid requirements remains unknown. The aim of the present study was to determine the effect of spinal anaesthesia preceding general anaesthesia on opioid requirements, postoperative pain and biochemical cancer-free survival.

Methods

This before-and-after effectiveness study investigated effects of two different anaesthesia techniques in 636 patients with RRP. Three hundred eighteen consecutive patients in the SPA group (spinal anaesthesia preceding general anaesthesia) were compared with 318 patients in the GA group (general anaesthesia alone). The primary endpoint of the study was opioid consumption in the post-anaesthesia care unit. Secondary endpoints were intraoperative opioid consumption, postoperative pain, postoperative recovery time, the length of hospital-stay, persistence of pain 1 year after surgery and cancer-free survival. Differences between the groups were analysed by a two-sided t-test, χ²-test, Fisher’s exact test and Mann–Whitney U test and the influence of possible confounders on opioid consumption with a general linear model. Cancer-free survival was determined by Kaplan–Meier curves and group differences by log-rank tests and multivariable Cox regression analyses.

Results

The total amount of morphine equivalent administered postoperatively was 7.5 [6.9; 8.1] mg in the SPA group and 6.0 [5.5; 6.5] mg in the GA group (mean [95% CI], p < 0.001). The amount of intraoperative sufentanil was 56.9 [55.1; 58.7] μg in the SPA group and 84.5 [82.5; 86.5] μg in the GA group (mean [95% CI], p < 0.001). There was no difference found in the postoperative pain level, length of hospital-stay and pain level 1 year after surgery. Biochemical cancer-free survival was highly related to TNM stage (p < 0.001, pT3 vs. pT2 hazard ratio 5.4 [95%CI 3.3; 9.2]) but not to the type of anaesthesia (p = 0.29).

Conclusions

Spinal anaesthesia preceding general anaesthesia for RRP is associated with increased postoperative opioid consumption compared to general anaesthesia alone. Postoperative pain level and the oncological outcome are not affected by the adjunctive use of spinal anaesthesia. Thus, the addition of spinal anaesthesia to general anaesthesia has no advantage in RRP.

Trial registration

ClinicalTrial.gov, NCT03565705.

The Effect of Intraoperative Fentanyl Consumption on Prognosis of Colorectal Liver Metastasis treated by Simultaneous Resection: A Propensity Score Matching Analysis

Background: No previous studies have reported the effect of intraoperative opioid consumption in colorectal liver metastasis (CRLM).

Methods: Medical records of patients who received simultaneous resection of CRLM were retrospectively reviewed. Patients with epidural anesthesia, intraoperative morphine, or intraoperative oxycodone were excluded. Patients were separated into high- and low-dose groups by median intraoperative equianalgesic fentanyl dose. Short-term outcomes, progression-free surcical (PFS) and overall survival (OS) were compared between groups before and after 1:1 propensity score matching (PSM). Univariable and multivariable Cox regression analysis were performed to identify independent predictors of survival.

Results: The final study population included 343 patients. Patients were separated into the low dose group (n=172) and the high dose group (n=171) by median intraoperative equianalgesic fentanyl dose (8.33 μg/kg). After PSM, 55 patients in the low dose group were matched to 55 patients in the high dose group and the baseline characteristics of the two groups were balanced. The two groups had no statistically significance difference in severity and categories of postoperative complications before and after PSM. Before PSM, the two groups had similar PFS (median 10.2 vs. 12.4 months, P=0.54) and OS (median 59.0 vs. 58.3 months, P=0.76). Univariate and multivariate Cox regression analyses revealed no statistically significant association between intraoperative equianalgesic fentanyl and PFS (multivariate HR=0.852, 95% CI 0.655-1.11, P=0.235) and OS (multivariate HR=1, 95% CI 0.68-1.49, P = 0.981). After PSM, the two groups also had similar PFS (median 9.2 vs. 10.7 months, P=0.98) and OS (median 51.0 vs. 46.0 months, P=0.39). Univariate and multivariate Cox regression analyses revealed no statistically significant association between intraoperative equianalgesic fentanyl and PFS (multivariate HR=1.05, 95% CI 0.632-1.73, P=0.861) and OS (multivariate HR=1.74, 95% CI 0.892-3.38, P = 0.105).

Conclusion: Intraoperative opioids consumption was not correlated with outcomes of CRLM patients treated with simultaneous resection.

Less Well-Known Consequences of the Long-Term Use of Opioid Analgesics: A Comprehensive Literature Review

BACKGROUND

The adverse effects of short-term opioid analgesics are well known and acknowledged; however, the spectrum of the sequelae of long-term use seems less clear. Some effects may remain undetected but still have the potential to cause harm and reduce patients' quality of life.

OBJECTIVE

To review the literature on the adverse effects of long-term opioid therapy.

METHODS

We performed a quasi-systematic search, analyzing articles published in the MEDLINE database between January 2000 and March 2021 that identified adverse effects of opioids used for chronic pain treatment.

RESULTS

Growing evidence indicates that there are multiple serious adverse effects of opioid treatment. Long-term opioid use may have significant effects on the endocrine, immune, cardiovascular, respiratory, gastrointestinal, and neural systems. Studies show that long-term opioid treatment increases the risk of fractures, infections, cardiovascular complications, sleep-disordered breathing, bowel dysfunction, overdose, and mortality. Opioids may potentially affect cancer development. Most consequences of the long-term use of opioids have been identified in studies of patients with non-malignant pain.

CONCLUSION

Studies indicate that long-term use of opioids increases the risk of drug-related events in a significant number of patients. Clinicians should be aware of these complications associated with prescribing opioids, discuss them with patients, prevent complications, if possible, and diagnose them early and manage adequately. More human studies are needed to assess the risk, including trials with individual opioids, because they have different adverse effect profiles.

Opioids and Breast Cancer Recurrence: A Systematic Review

Breast cancer has the greatest epidemiological impact in women. Opioids represent the most prescribed analgesics, both in surgical time and in immediate postoperative period, as well as in chronic pain management as palliative care. We made a systematic review analyzing the literature's evidence about the safety of opioids in breast cancer treatment, focusing our attention on the link between opioid administration and increased relapses. The research has been conducted using the PubMed database. Preclinical studies, retrospective and prospective clinical studies, review articles and original articles were analyzed. In the literature, there are several preclinical in vitro and in vivo studies, suggesting a possible linkage between opioids administration and progression of cancer disease. Nevertheless, these results are not confirmed by clinical studies. The most recent evidence reassures the safety of opioids during surgical time as analgesic associated with anesthetics drugs, during postoperative period for optimal cancer-related pain management and in chronic use. Currently, there is controversial evidence suggesting a possible impact of opioids on breast cancer progression, but to date, it remains an unresolved issue. Although there is no conclusive evidence, we hope to arouse interest in the scientific community to always ensure the best standards of care for these patients.

Anesthetics or anesthetic techniques and cancer surgical outcomes: a possible link

As of 2018 cancer is responsible for almost 9.6 million deaths annually and, with an aging population, the incidence of cancer is expected to continue to rise. Surgery is an important treatment modality for patients with solid organ cancers. It has been postulated that, due to potentially overlapping processes underlying the development of malignancy and the therapeutic pathways of various anesthetic agents, the choice of anesthetic type and method of administration may affect post-operative outcomes in patients with cancer. This is a literature review of the most recent evidence extracted from various databases including PubMed, EMBASE, and the Cochrane, as well as journals and book reference lists. The review highlights the pathophysiological processes underpinning cancer development and the molecular actions of anesthetic agents, pre-clinical and retrospective studies investigating cancer and anesthetics, as well as ongoing clinical trials. Overall, there are conflicting results regarding the impact of regional vs. general anesthesia on cancer recurrence, whilst the majority of data suggest a benefit of the use of intravenous propofol over inhalational volatile anesthetics. The biological changes associated with the surgical inflammatory response offer a unique opportunity to intervene to counteract any potentially cancer-promoting effects.

MR-guided microwave ablation of hepatocellular carcinoma (HCC): is general anesthesia more effective than local anesthesia?

Background

Percutaneous magnetic resonance-guided (MR-guided) MWA procedures have traditionally been performed under local anesthesia (LA) and sedation. However, pain control is often difficult to manage, especially in some cases when the tumor is large or in a specific location, such as near the abdominal wall or close to the hepatic dome. This study retrospectively compared the results of general anesthesia (GA) and local anesthesia (LA) for MR-guided microwave ablation (MWA) in patients with hepatocellular carcinoma (HCC ≤ 5.0 cm) to investigate whether different anesthesia methods lead to different clinical outcomes.

Methods

The results of the analysis include procedure-related complications, imaging response, and the time to complete two sets of procedures. According to the type of anesthesia, the Kaplan-Meier method was used to compare the local tumor progression (LTP) of the two groups who underwent MR-guided MWA.

Results

All patients achieved technical success. The mean ablation duration of each patient in the GA group and LA group was remarkably different (P = 0.012). Both groups had no difference in complications or LTP (both P > 0.05). Notably, the tumor location (challenging locations) and the number of lesions (2–3 lesions) could be the main factors affecting LTP (p = 0.000, p = 0.015). Univariate Cox proportional hazard regression indicated that using different anesthesia methods (GA and LA) was not associated with longer LTP (P = 0.237), while tumor location (challenging locations) and the number of lesions (2–3 lesions) were both related to shorter LTP (P = 0.000, P = 0.020, respectively). Additionally, multivariate Cox regression further revealed that the tumor location (regular locations) and the number of lesions (single) could independently predict better LTP (P = 0.000, P = 0.005, respectively).

Conclusions

No correlation was observed between GA and LA for LTP after MR-guided MWA. However, tumors in challenging locations and the number of lesions (2–3 lesions) appear to be the main factors affecting LTP.

The role of opioids in cancer response to immunotherapy

Background

The response to immunotherapy can be impaired by several factors including external intervention such as drug interactions with immune system. We aimed to examine the immunomodulatory action of opioids, since immune cells express opioid receptors able to negatively influence their activities.

Methods

This observational, multicenter, retrospective study, recruited patients with different metastatic solid tumors, who have received immunotherapy between September 2014 and September 2019. Immunotherapy was administered according to the standard schedule approved for each primary tumor and line of treatment. The concomitant intake of antibiotics, antifungals, corticosteroids and opioids were evaluated in all included patients. The relationship between tumor response to immunotherapy and the oncological outcomes were evaluated. A multivariate Cox-proportional hazard model was used to identify independent prognostic factors for survival.

Results

One hundred ninety-three patients were recruited. Overall, progression-free survival (PFS) and overall survival (OS) were significantly shorter in those patients taking opioids than in those who didn’t (median PFS, 3 months vs. 19 months, HR 1.70, 95% CI 1.37–2.09, p < 0.0001; median OS, 4 months vs. 35 months, HR 1.60, 95% CI 1.26–2.02, p < 0.0001). In addition, PFS and OS were significantly impaired in those patients taking corticosteroids, antibiotics or antifungals, in those patients with an ECOG PS ≥ 1 and in patients with a high tumor burden. Using the multivariate analyses, opioids and ECOG PS were independent prognostic factors for PFS, whereas only ECOG PS resulted to be an independent prognostic factor for OS, with trend toward significance for opioids as well as tumor burden.

Discussion

Our study suggests that the concomitant administration of drugs as well as some clinical features could negatively predict the outcomes of cancer patients receiving immunotherapy. In particular, opioids use during immunotherapy is associated with early progression, potentially representing a predictive factor for PFS and negatively influencing OS as well.

Conclusions

A possible negative drug interaction able to impair the immune response to anti-PD-1/PD-L1 agents has been highlighted. Our findings suggest the need to further explore the impact of opioids on immune system modulation and their role in restoring the response to immunotherapy treatment, thereby improving patients' outcomes.

Semi-automated tracking of pain in critical care patients using artificial intelligence: a retrospective observational study

Monitoring the pain intensity in critically ill patients is crucial because intense pain can cause adverse events, including poor survival rates; however, continuous pain evaluation is difficult. Vital signs have traditionally been considered ineffective in pain assessment; nevertheless, the use of machine learning may automate pain assessment using vital signs. This retrospective observational study was performed at a university hospital in Sendai, Japan. Objective pain assessments were performed in eligible patients using the Critical-Care Pain Observation Tool (CPOT). Three machine-learning methods—random forest (RF), support vector machine (SVM), and logistic regression (LR)—were employed to predict pain using parameters, such as vital signs, age group, and sedation levels. Prediction accuracy was calculated as the harmonic mean of sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC). Furthermore, 117,190 CPOT assessments were performed in 11,507 eligible patients (median age: 65 years; 58.0% males). We found that pain prediction was possible with all three machine-learning methods. RF demonstrated the highest AUROC for the test data (RF: 0.853, SVM: 0.823, and LR: 0.787). With this method, pain can be objectively, continuously, and semi-automatically evaluated in critically ill patients.

The association of prescription opioid use with incident cancer: A Surveillance, Epidemiology, and End Results-Medicare population-based case-control study

BACKGROUND

Cancer is the second leading cause of death globally, and researchers seek to identify modifiable risk factors Over the past several decades, there has been ongoing debate whether opioids are associated with cancer development, metastasis, or recurrence. Basic science, clinical, and observational studies have produced conflicting results. The authors examined the association between prescription opioids and incident cancers using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. A complex relation was observed between prescription opioids and incident cancer, and cancer site may be an important determinant.

METHODS

By using linked SEER cancer registry and Medicare claims from 2008 through 2013, a case-control study was conducted examining the relation between cancer onset and prior opioid exposure. Logistic regression was used to account for differences between cases and controls for 10 cancer sites.

RESULTS

Of the population studied (n = 348,319), 34% were prescribed opioids, 79.5% were white, 36.9% were dually eligible (for both Medicare and Medicaid), 13% lived in a rural area, 52.7% had ≥1 comorbidity, and 16% had a smoking-related diagnosis. Patients exposed to opioids had a lower odds ratio (OR) associated with breast cancer (adjusted OR, 0.96; 95% CI, 0.92-0.99) and colon cancer (adjusted OR, 0.90; 95% CI, 0.86-0.93) compared with controls. Higher ORs for kidney cancer, leukemia, liver cancer, lung cancer, and lymphoma, ranging from lung cancer (OR, 1.04; 95% CI, 1.01-1.07) to liver cancer (OR, 1.19; 95% CI, 1.08-1.31), were present in the exposed population.

CONCLUSIONS

The current results suggest that an association exists between prescription opioids and incident cancer and that cancer site may play an important role. These findings can direct future research on specific patient populations that may benefit or be harmed by prescription opioid exposure.

Impact of anesthesia and analgesia techniques on glioblastoma progression. A narrative review

Glioblastoma (GBM) is an aggressive malignant CNS tumor with a median survival of 15 months after diagnosis. Standard therapy for GBM includes surgical resection, radiation, and temozolomide. Recently, anesthetics and analgesics have received attention for their potential involvement in mediating tumor growth. This narrative review investigated whether various members of the 2 aforementioned classes of drugs have a definitive impact on GBM progression by summarizing pertinent in vitro, in vivo, and clinical studies. Recent publications regarding general anesthetics have been inconsistent, showing that they can be pro-tumoral or antitumoral depending on the experimental context. The local anesthetic lidocaine has shown consistent antitumoral effects in vitro. Clinical studies looking at anesthetics have not concluded that their use improves patient outcomes. In vitro and in vivo studies looking at opioid involvement in GBM have demonstrated inconsistent findings regarding whether these drugs are pro-tumoral or antitumoral. Nonsteroidal anti-inflammatory drugs, and specifically COX-2 inhibitors, have shown inconsistent findings across multiple studies looking at whether they are beneficial in halting GBM progression. Until multiple repeatable studies show that anesthetics and analgesics can suppress GBM growth, there is no strong evidence to recommend changes in the anesthetic care of these patients.

Which idea is better with regard to immune response? Opioid anesthesia or opioid free anesthesia

The stress of surgery is characterized by an inflammatory response with immune suppression resulting from many factors, including the type of surgery and the kind of anesthesia, linked with the drugs that are used and the underlying disease of the patient. The trauma of surgery triggers a cascade of reactions involving the immune response and nociception. As strong analgesics, opioids provide the analgesic component of general anesthesia with bi-directional effect on the immune system. Opioids influence almost all aspects of the immune response in regards to leukocytes, macrophages, mast cells, lymphocytes, and NK cells. The suppressive effect of opioids on the immune system is limiting their use, especially in patients with impaired immune response, so the possibility of using multimodal anesthesia without opioids, known as opioid-free anesthesia (OFA), is gaining more and more sympathizers. The idea of OFA is to eliminate opioid analgesia in the treatment of acute pain and to replace it with drugs from other groups that are assumed to have a comparable analgesic effect without affecting the immune system. Here, we present a review on the impact of anesthesia, with and without the use of opioids, on the immune response to surgical stress.

COVID-19: Pain Management in Patients with SARS-CoV-2 Infection-Molecular Mechanisms, Challenges, and Perspectives

Since the end of 2019, the whole world has been struggling with the pandemic of the new Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2). Available evidence suggests that pain is a common symptom during Coronavirus Disease 2019 (COVID-19). According to the World Health Organization, many patients suffer from muscle pain (myalgia) and/or joint pain (arthralgia), sore throat and headache. The exact mechanisms of headache and myalgia during viral infection are still unknown. Moreover, many patients with respiratory failure get admitted to the intensive care unit (ICU) for ventilatory support. Pain in ICU patients can be associated with viral disease itself (myalgia, arthralgia, peripheral neuropathies), may be caused by continuous pain and discomfort associated with ICU treatment, intermittent procedural pain and chronic pain present before admission to the ICU. Undertreatment of pain, especially when sedation and neuromuscular blocking agents are used, prone positioning during mechanical ventilation or extracorporeal membrane oxygenation (ECMO) may trigger delirium and cause peripheral neuropathies. This narrative review summarizes current knowledge regarding challenges associated with pain assessment and management in COVID-19 patients. A structured prospective evaluation should be undertaken to analyze the probability, severity, sources and adequate treatment of pain in patients with COVID-19 infection.

General Anesthetics on Immune System Cytokines: A Narrative Review Article

Context

According to the previous studies, general anesthesia influences the immune system. Evaluating such impacts on the immune system helps to improve the management of anesthesia.

Evidence Acquisition

The current review aimed to summarize the literature related to the effects of general anesthesia agents on the cytokines. Google Scholar, PubMed, and ISI/Web of Sciences databases were searched using the following keywords: cytokine, general anesthesia, immune response, intravenous anesthetics, volatile anesthetics, opioids, benzodiazepines, and controlled ventilation.

Results

Long-term administration of general anesthesia drugs, due to their effects on cytokines, can lead to disease progression in patients with immune deficiency. Due to the conflicting results of various studies and the increasing number of patients with immune deficiency, the choice of the appropriate general anesthesia agents facilitates achieving the more favorable function of the cytokines.

Conclusions

It seems that the effect of general anesthesia on the immune system in healthy patients and short-term surgeries is not considerable and changes in the immune system are related to surgical trauma, particularly in major surgery.

The immunosuppressive effects of volatile versus intravenous anesthesia combined with epidural analgesia on kidney cancer: a pilot randomized controlled trial

Background

The aim of this study was to test the hypothesis that the use of inhalational anesthesia leads to higher suppression of the cell-mediated immunity compared to total intravenous anesthesia in patients undergoing kidney cancer surgery under combined low thoracic epidural analgesia and general anesthesia.

Methods

Patients were randomly allocated to either propofol-based (intravenous anesthetic) or sevoflurane-based (volatile anesthetic) anesthesia group with 10 patients in each group, along with epidural analgesia in both groups. Amounts of natural killer (NK) cells, total T lymphocytes, and T lymphocyte subpopulations in the blood samples collected from the patients before surgery, at the end of the surgery and postoperative days 1, 3 and 7 were determined by flow cytometric analysis. The NK cell count served as the primary endpoint of the study, whereas the total T lymphocyte count and cell counts for T lymphocyte subpopulations were used as the secondary endpoint.

Results

Our study showed that there were no significant differences in the amount of NK cells, total T lymphocytes, regulatory T cells, and T-helper cells, cytotoxic T lymphocytes, and their subpopulations between the propofol- and sevoflurane-based anesthesia groups when the anesthesia was administered in combination with epidural analgesia.

Conclusions

The results of this pilot study did not support the hypothesis that the use of inhalational anesthesia leads to higher suppression of the cell-mediated immunity than that of total intravenous anesthesia in patients undergoing kidney cancer surgery under combined low thoracic epidural analgesia and general anesthesia.

Opioids in Cancer Development, Progression and Metastasis: Focus on Colorectal Cancer

OPINION STATEMENT

So far, opioids have been successfully used to reduce cancer pain in patients in order to improve their quality of life. However, the use of opioids leads to numerous side effects such as constipation, drowsiness, nausea, itching, increased sweating and hormonal changes. In this review, we described the action of opioids in several molecular pathways significant for maintenance of the intestinal homeostasis including the impact on the intestinal epithelium integrity, changes in microbiome composition, modulation of the immune system or induction of apoptosis and inhibition of angiogenesis. We summed up the role of individual opioids in the processes involved in the growth and development of cancer and elucidated if targeting opioid receptors may constitute novel therapeutic option in colon cancer.

Suppression of Human Natural Killer Cells by Different Classes of Opioids

BACKGROUND

The use of regional and other opioid-sparing forms of anesthesia has been associated with a decrease in the recurrence of certain malignancies. Direct suppression of human natural killer cells by opioids has been postulated to explain this observation. However, the effect of different classes of opioids on suppression of natural killer cell cytotoxicity has not been systematically characterized.

METHODS

After confirming that freshly isolated natural killer cells from peripheral human blood express opioid receptors, cells were incubated with increasing concentrations of clinically used or receptor-specific opioid agonists. We also evaluated the effect of pretreatment with receptor-specific antagonists or naloxone. Treated natural killer cells were then coincubated with a carboxyfluorescein succinimidyl ester-labeled target tumor cell line, K562. Annexin V staining was used to compare the percent of tumor cell apoptosis in the presence of opioid-pretreated and untreated natural killer cells. Treated samples were compared to untreated samples using Kruskal-Wallis tests with a post hoc Dunn correction.

RESULTS

Morphine, methadone, buprenorphine, loperamide, [D-Ala2, N-MePhe4, Gly-ol]-enkephalin, and U-50488 significantly decreased natural killer cell cytotoxicity. When natural killer cells were pretreated with naloxone, cyprodime, and nor-binaltorphimine before exposure to morphine, there was no difference in natural killer cytotoxicity, compared to the amount observed by untreated natural killer cells. Fentanyl, O-desmethyltramadol, and [D-Pen2,D-Pen5] enkephalin did not change natural killer cell cytotoxicity compare to untreated natural killer cells.

CONCLUSIONS

Incubation of isolated natural killer cells with certain opioids causes a decrease in activity that is not observed after naloxone pretreatment. Suppression of natural killer cell cytotoxicity was observed with μ- and κ-receptor agonists but not δ-receptor agonists. These data suggest that the effect is mediated by μ- and κ-receptor agonism and that suppression is similar with many clinically used opioids.

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.

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.

Morphine inhibits cell viability and growth via suppression of vascular endothelial growth factor in human oral cancer HSC-3 cells

PURPOSE

Although many oral cancer patients require opioids, the effects of morphine and related drugs on oral cancer progression have not been well established. Thus, we examined the effects of morphine exposure on the viability of human oral squamous carcinoma HSC-3 cells and aimed to identify the underlying mechanism.

METHODS

We exposed HSC-3 cells to the various concentrations of morphine (0, 0.1, 1, 10, 100, or 1000 μmol/L) for 48 h and, subsequently, evaluated cell viability using the 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay and cytotoxicity using the lactate dehydrogenase (LDH) assay. To explore the effects of morphine on cell proliferation further, colony formation assay and cell cycle analysis were performed. Additionally, the intracellular expression of nuclear factor kappa B (NF-κB) was analyzed using flow cytometry, and vascular endothelial growth factor (VEGF)-A was evaluated using human VEGF assay.

RESULTS

Morphine exposure reduced cell viability and enhanced cytotoxicity in HSC-3 cells in a concentration-dependent manner. The number of colonies in the morphine-treated groups was significantly lower than that in the control group. Consistent with these results, morphine exposure significantly reduced the concentration of VEGF in the cell culture medium in a concentration-dependent manner. However, our data show that morphine at clinical concentrations (0.1-10 μmol/L) does not affect cell cycle and apoptosis.

CONCLUSIONS

Our results suggest that in human oral cancer HSC-3 cells, morphine exposure inhibits cell viability and growth via suppression of VEGF in clinical conditions.

Effect of High Postoperative Body Temperature on Long-Term Prognosis in Patients with Gastric Cancer After Radical Resection

BACKGROUND

There is a lack of data on the effect of high postoperative body temperature on disease-free survival (DFS) in patients who underwent radical gastrectomy.

METHODS

Patients who underwent radical gastrectomy from January 2006 to December 2011 were selected. The highest body temperature within 1 week after operation was used to establish diagnostic thresholds for high and low body temperature through X-tile software.

RESULTS

A total of 1396 patients were included in the analysis. The diagnostic threshold for high body temperature was defined as 38 °C; 370 patients were allocated to the high-temperature group (HTG), while another 1026 patients were allocated to the low-temperature group (LTG). For all patients, survival analysis showed that 5-year DFS in the HTG was significantly lower than that for the LTG (55.6% vs 63.9%, P = 0.007). Multivariate analysis revealed that high postoperative body temperature was an independent prognostic risk factor for 5-year DFS (HR = 1.288 (1.067-1.555), P = 0.008). For patients without complications, survival analysis showed that the 5-year DFS rate in the HTG was lower than that for the LTG (57.5% vs 64.4%, P = 0.051), especially in patients with stage III gastric cancer (31.3% vs 41.7%, P = 0.037). For patients with complications or infectious complications, there were no significant differences between the HTG and LTG regarding 5-year DFS (49.3% vs 58.2%, P = 0.23 and 49.4% vs 55.1%, P = 0.481, respectively).

CONCLUSION

For stage III gastric cancer patients without complications, high postoperative body temperature can significantly reduce the 5-year DFS. These patients may benefit from more aggressive adjuvant therapy and postoperative surveillance regimens.

Intrathecal Morphine Administration Does Not Affect Survival After Liver Resection for Hepatocellular Carcinoma

Introduction. Opioids may influence tumor recurrence and cancer-free survival in hepatocellular carcinoma (HCC). The relationship between intrathecal morphine administration, tumor recurrence, and patient survival after hepatectomy for HCC is unknown. Patients and Methods. This single-center, retrospective study included 1837 liver resections between July 2002 and December 2012; 410 cases were incorporated in the final univariate and multivariate analysis. Confirmatory propensity matching yielded 65 matched pairs (intrathecal morphine vs none). Primary outcomes were recurrence of HCC and survival. Secondary outcomes included characterization of factors associated with recurrence and survival. Results. Groups were similar except for increased coronary artery disease in the no intrathecal morphine group. All patients received volatile anesthesia. Compared with no intrathecal morphine (N = 307), intrathecal morphine (N = 103) was associated with decreased intraoperative intravenous morphine administration (median difference = 12.5 mg; 95% confidence interval [CI] = 5-20 mg). There was no difference in blood loss, transfusion, 3- or 5-year survival, or recurrence in the univariate analysis. Multivariate analysis identified covariates that significantly correlated with 5-year survival: intrathecal morphine (hazard ratio [HR] = 0.527, 95% CI = 0.296-0.939), lesion diameter (HR = 1.099, 95% CI = 1.060-1.141), vascular invasion (HR = 1.658, 95% CI = 1.178-2.334), and satellite lesions (HR = 2.238, 95% CI = 1.447-3.463). Survival analysis on the propensity-matched pairs did not demonstrate a difference in 5-year recurrence or survival. Discussion and Conclusion. Multivariate analysis revealed a significant association between intrathecal morphine and 5-year survival. This association did not persist after propensity matching. The association between intrathecal morphine and HCC recurrence and survival remains unclear and prospective work is necessary to determine whether an association exists.

Effects of dezocine and sufentanyl for postoperative analgesia on activity of NK, CD4+ and CD8+ cells in patients with breast cancer

The effects of dezocine and sufentanyl on the activity of natural killer (NK), CD4⁺ and CD8⁺ cells in patients with breast cancer undergoing postoperative analgesia after radical mastectomy were compared. The clinical data of 76 female patients undergoing radical mastectomy in the Fudan University Shanghai Cancer Center from January 2015 to October 2017 were analyzed retrospectively. Forty-two patients treated with dezocine were group D and 34 patients with sufentanyl were group S. Visual analogue scale (VAS) was used to evaluate the analgesic effect at 3, 12, 24, 48 h after surgery. There was no significant difference in VAS score, NK cells, CD4⁺ cells, and CD8⁺ cell vitality at 3 h postoperatively between the two groups (P>0.05), and VAS score at 12, 24 and 48 h postoperatively in the S group was significantly lower than that in group D (P<0.05). The activity of NK cells and CD4⁺ cells at 3, 12, 24 and 48 h after surgery in group D was significantly higher than that in group S, and the difference was statistically significant (P<0.05). The activity of CD8⁺ cells at 3, 12, 24 and 48 h after surgery in group D was significantly lower than that in group S, and the difference was statistically significant (P<0.05). The analgesic effect of dezocine was slightly worse than that of sufentanyl, but it was more beneficial to the recovery of early postoperative immune function.

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.

Postoperative Fever Evaluation Following Lumbar Fusion Procedures

Objective

This study aimed to determine the incidence of postoperative fever, the workup conducted for postoperative fever, the rate of subsequent fever-related diagnoses or complications, and the risk factors associated with fever following lumbar fusion.

Methods

A retrospective review of patients undergoing lumbar fusion was performed. For patients in whom fever (≥38.6°C) was documented, charts were reviewed for any fever workup or diagnosis. Multivariate regression was used to identify independent risk factors for the development of postoperative fever.

Results

A total of 868 patients met the inclusion criteria, of whom 105 exhibited at least 1 episode of fever during hospitalization. The first documentation of fever occurred during the first 24 hours in 43.8% of cases, during postoperative hours 24–48 in 53.3%, and later than 48 hours postoperatively in 2.9%. At least 1 component of a fever workup was conducted in 47 of the 105 patients who had fever, resulting in fever-associated diagnoses in 4 patients prior to discharge. Three patients who had fever during the inpatient stay developed complications after discharge. On multivariate analysis, operations longer than 150 minutes (relative risk [RR], 1.66; p=0.015) and narcotic consumption greater than 85 oral morphine equivalents on postoperative day 0 (RR, 1.53; p=0.038) were independently associated with an increased risk of developing postoperative fever.

Conclusion

The results of this study suggest that inpatient fever occurred in roughly 1 in 8 patients following lumbar fusion surgery. In most cases where a fever workup was performed, no cause of fever was detected. Longer operative time and increased early postoperative narcotic use may increase the risk of developing postoperative fever.

The Effect of Anesthesia on the Immune System in Colorectal Cancer Patients

Colorectal cancer (CRC) is the key leading cause of high morbidity and mortality worldwide. Surgical excision is the most effective treatment for CRC. However, stress caused by surgery response can destroy the body's immunity and increase the likelihood of cancer dissemination and metastasis. Anesthesia is an effective way to control the stress response, and recent basic and clinical research has shown that anesthesia and related drugs can directly or indirectly affect the immune system of colorectal cancer patients during the perioperative period. Thus, these drugs may affect the prognosis of CRC surgery patients. This review is intended to summarize currently available data regarding the effects of anesthetics and related drugs on perioperative immune function and postoperative recurrence and metastasis in CRC patients. Determining the most suitable anesthesia for patients with CRC is of utmost importance.

Postoperative opioids, endocrine changes, and immunosuppression

Opioids are among most effective drugs for managing acute postoperative pain. This article discusses the potential effects of perioperative opioids on endocrine and immune function.

Consideration of pain felt by patients in the ICU

Patients in the ICU are often treated under extreme conditions, with the patient often fearful of losing his life or experiencing severe pain. As a result, high-quality pain management is required. However, response to pain is often inadequate due to continuous administration of sedatives, difficulties in communicating with intubated patients, and/or poor awareness of pain in patients not receiving surgery. Reports on difficulties in pain management in the ICU are many, but few consider the correlation between pain management and patient prognosis. Consequently, consideration on how to implement pain control activities in the ICU to improve patient prognosis is needed.

The effect of neuraxial anesthesia on cancer recurrence and survival after cancer surgery: an updated meta-analysis

Several animal and observational studies have evaluated the effects of neuraxial anesthesia on the recurrence and survival of cancer surgery; studies reported benefit, whereas others did not. To provide further evidence that neuraxial anesthesia(combined with or without general anesthesia (GA))may be associated with reduced cancer recurrence and long-term survival after cancer surgery, we conducted this meta-analysis. A total of 21 studies were identified and analyzed, based on searches conducted using PubMed, Web of Science, EMBASE database and the Cochrane Database of Systematic Reviews. After data abstraction, adjusted hazard ratios (HR) with 95% confidence intervals (CIs) were used to assess the impact of neuraxial anesthesia (combined with or without GA) and GA on oncological outcomes after cancer surgery. For overall survival (OS), a potential association between neuraxial anesthesia and improved OS (HR 0.853, CI 0.741-0.981, P = 0.026, the random-effects model) was observed compared with GA. Specifically, we found a positive association between neuraxial anesthesia and improved OS in colorectal cancer (HR 0.653, CI 0.430-0.991, P = 0.045, the random-effects model). For recurrence-free survival (RFS), a significant association between neuraxial anesthesia and improved RFS (HR 0.846, CI 0.718-0.998, P = 0.047, the random-effects model) was detected compared with GA. Our meta-analysis suggests that neuraxial anesthesia may be associated with improved OS in patients with cancer surgery, especially for those patients with colorectal cancer. It also supports a potential association between neuraxial anesthesia and a reduced risk of cancer recurrence. More prospective studies are needed to elucidate whether the association between neuraxial use and survival is causative.

Intraoperative Fentanyl Consumption Does Not Impact Cancer Recurrence or Overall Survival after Curative Colorectal Cancer Resection

Whether opioid use in cancer surgery would promote tumor dissemination in humans is inconclusive. We investigated the effect of intraoperative fentanyl dose on colorectal cancer (CRC) prognosis following resection in this retrospective study. A total of 1679 patients with stage I-III CRC undergoing tumor resection between January 2011 and December 2014 were evaluated through August 2016. Postoperative recurrence-free survival (RFS) and overall survival (OS) were analyzed using Cox regression models. Multivariable Cox regression analysis demonstrated no dose-response association between the amount of fentanyl dose and RFS (adjusted hazard ratio: 1.03, 95% CI: 0.89-1.19) or OS (adjusted hazard ratio: 0.84, 95% CI: 0.64-1.09). Patients were further classified into the high- and low-dose groups by the median of fentanyl dose (3.0 μg·kg^-1), and there was no significant difference in RFS or OS between groups, either (adjusted hazard ratio: 0.93, 95% CI: 0.74-1.17 for RFS; 0.79, 95% CI: 0.52-1.19 for OS). We concluded that intraoperative fentanyl consumption has no impact on recurrence-free or overall survival in patients after curative CRC resection.

Influence of opioids on immune function in patients with cancer pain: from bench to bedside

In patients with cancer, opioids are principally used for the management of acute surgical and chronic cancer-related pain. However, opioids have many non-analgesic effects, including direct and indirect effects on cancer cells and on anti-tumour immunity (NK cells, macrophages and T-cells). Direct effects on immune cells are manifested via opioid and non-opioid toll-like receptors, whereas indirect effects are manifested via the sympathetic nervous system and hypothalamic-pituitary-adrenal axis. Opioids can also decrease/alter immune cell infiltration into the tumour micro-environment. Animal models have shown that this is not a class effect, in that morphine and fentanyl suppress NK cell cytotoxicity; buprenorphine does not affect NK cell cytotoxicity, whereas tramadol increases NK cell cytotoxicity, reducing metastasis. In healthy individuals, morphine suppresses and fentanyl enhances NK cell cytotoxicity. In patients undergoing surgery, fentanyl decreased and tramadol increased NK cell cytotoxicity; clinical outcomes were not determined. Meta-analyses of opioid-sparing surgical studies report an association between improved recurrence-free and/or overall survival with regional/neuraxial anaesthesia compared with systemic opioids. In patients receiving opioids for non-surgical cancer-related pain, morphine has variable effects on immunity; clinical outcomes were not assessed. Although there is a potential association between systemic opioid administration and shorter survival in cancer patients with a prognosis of months to years, studies have not been designed to primarily assess survival, as a consequence of which causality cannot be apportioned. Pain is immunosuppressive, so analgesia is important. Opioids for cancer-related pain will continue to be recommended until definitive data on the effects of opioids on clinical outcomes in specific patient groups becomes available.

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.

Effects of Postoperative Pain Management on Immune Function After Laparoscopic Resection of Colorectal Cancer: A Randomized Study

There has been a rising interest in the possible association between perioperative opioid use and postoperative outcomes in cancer patients. Continuous surgical wound infiltration with local anesthetics is a nonopioid analgesic technique that can be used as a postoperative pain management alternative to opioid-based intravenous patient-controlled analgesia (IV PCA). The aim of this study was to compare the effects of an opioid-based analgesic regimen versus a local anesthetic wound infiltration-based analgesic regimen on immune modulation and short-term cancer recurrence or metastasis in patients undergoing laparoscopic resection of colorectal cancer.Sixty patients undergoing laparoscopic resection of colorectal cancer were randomly assigned to either the opioid group or the ON-Q group. For postoperative analgesia during the first 48 hours, the opioid group (n = 30) received fentanyl via IV PCA, whereas the ON-Q group (n = 30) received continuous wound infiltration of 0.5% ropivacaine with an ON-Q pump and tramadol via IV PCA. Pethidine for the opioid group and ketorolac or propacetamol for the ON-Q group were used as rescue analgesics. Anesthesia was induced and maintained with propofol and remifentanil. The primary outcome was postoperative immune function assessed by natural killer cell cytotoxicity (NKCC) and interleukin-2. Secondary outcomes were postoperative complications, cancer recurrence, or metastasis within 1 year after surgery, and postoperative inflammatory responses measured by white blood cell count, neutrophil percentage, and C-reactive protein. Immune function and inflammatory responses were measured before surgery and 24 and 48 hours after surgery.Fifty-nine patients completed the study. In the circumstance of similar pain control efficacy between the opioid group and the ON-Q group, postoperative NKCC and interleukin-2 levels did not differ between the 2 groups. The incidence of postoperative complications and recurrence or metastasis within 1 year after surgery was comparable between the groups. Postoperative inflammatory responses were also similar between the groups.When compared with ropivacaine wound infiltration-based analgesia, fentanyl-based analgesia did not further decrease NKCC or affect short-term cancer recurrence or metastasis. Thus, a fentanyl-based analgesic regimen and a ropivacaine wound infiltration-based analgesic regimen can both be used for postoperative pain management in laparoscopic resection of colorectal cancer.

Effect of Propofol and Desflurane on Immune Cell Populations in Breast Cancer Patients: A Randomized Trial

Several factors can affect the perioperative immune function. We evaluated the effect of propofol and desflurane anesthesia on the surgery-induced immune perturbation in patients undergoing breast cancer surgery. The patients were randomly assigned to receive propofol (n = 20) or desflurane (n = 20) anesthesia. The total and differential white blood cell counts were determined with lymphocyte subpopulations before and 1 hr after anesthesia induction and at 24 hr postoperatively. Plasma concentrations of interleukin (IL)-2 and IL-4 were also measured. Both propofol and desflurane anesthesia preserved the IL-2/IL-4 and CD4(+)/CD8(+) T cell ratio. Leukocytes were lower in the propofol group than in the desflurane group at 1 hr after induction (median [quartiles], 4.98 [3.87-6.31] vs. 5.84 [5.18-7.94] 10(3)/µL) and 24 hr postoperatively (6.92 [5.54-6.86] vs. 7.62 [6.22-9.21] 10(3)/µL). NK cells significantly decreased 1 hr after induction in the propofol group (0.41 [0.34-0.53] to 0.25 [0.21-0.33] 10(3)/µL), but not in the desflurane group (0.33 [0.29-0.48] to 0.38 [0.30-0.56] 10(3)/µL). Our findings indicate that both propofol and desflurane anesthesia for breast cancer surgery induce a favorable immune response in terms of preservation of IL-2/IL-4 and CD4(+)/CD8(+) T cell ratio in the perioperative period. With respect to leukocytes and NK cells, desflurane anesthesia is associated with less adverse immune responses than propofol anesthesia during surgery for breast cancer. (Clinical trial registration at https://cris.nih.go.kr/cris number: KCT0000939).

Opioid treatment of experimental pain activates nuclear factor-κB

OBJECTIVE

To determine the independent and combined effects of pain and opioids on the activation of an early marker of inflammation, nuclear factor-κB (NF-κB).

DESIGN

NF-κB activation was compared within-subjects following four randomly ordered experimental sessions of opioid-only (intravenous fentanyl 1 μg/kg), painonly (cold-pressor), opioid + pain, and a resting condition.

SETTING

University General Clinical Research Center.

PARTICIPANTS

Twenty-one (11 female) healthy controls.

INTERVENTIONS

Following exposure to treatment (fentanyl administration and/or cold-pressor pain), blood samples for NF-κB analysis were obtained.

MAIN OUTCOME MEASURES

Intracellular levels of activated NF-κB, in unstimulated and stimulated peripheral blood mononuclear cells at 15 and 30 minutes.

RESULTS

Neither pain nor opioid administration alone effected NF-κB levels in cell populations; however, the combination of treatments induced significant increases of NF-κB in stimulated peripheral blood mononuclear cell, lymphocytes, and monocytes.

CONCLUSIONS

The combination of acute pain with opioids, as occurs in clinical situations, activates a key transcription factor involved in proinflammatory responses.

Segmental thoracic spinal has advantages over general anesthesia for breast cancer surgery

BACKGROUND

Thoracic spinal anesthesia has been used for laparoscopic cholecystectomy and abdominal surgeries, but not in breast surgery. The present study compared this technique with general anesthesia in breast cancer surgeries.

MATERIALS AND METHODS

Forty patients were enrolled in this comparative study with inclusion criteria of ASA physical status I-III, primary breast cancer without known extension beyond the breast and axillary nodes, scheduled for unilateral mastectomy with axillary dissection. They were randomly divided into two groups. The thoracic spinal group (S) (n = 20) underwent segmental thoracic spinal anesthesia with bupivacaine and fentanyl at T5-T6 interspace, while the other group (n = 20) underwent general anesthesia (G). Intraoperative hemodynamic parameters, intraoperative complications, postoperative discharge time from post-anesthesia care unit (PACU), postoperative pain and analgesic consumption, postoperative adverse effects, and patient satisfaction with the anesthetic techniques were recorded.

RESULTS

Intraoperative hypertension (20%) was more frequent in group (G), while hypotension and bradycardia (15%) were more frequent in the segmental thoracic spinal (S) group. Postoperative nausea (30%) and vomiting (40%) during PACU stay were more frequent in the (G) group. Postoperative discharge time from PACU was shorter in the (S) group (124 ± 38 min) than in the (G) group (212 ± 46 min). The quality of postoperative analgesia and analgesic consumption was better in the (S) group. Patient satisfaction was similar in both groups.

CONCLUSIONS

Segmental thoracic spinal anesthesia has some advantages when compared with general anesthesia and can be considered as a sole anesthetic in breast cancer surgery with axillary lymph node clearance.

A comparison of the effects of epidural analgesia versus traditional pain management on outcomes after gastric cancer resection: a population-based study

BACKGROUND AND OBJECTIVES

Epidural analgesia may increase survival after cancer surgery by reducing recurrence. This population-based study compared survival and treated recurrence after gastric cancer resection between patients receiving epidurals and those who did not.

METHODS

We used the linked federal Surveillance, Epidemiology, and End Results Program/Medicare database to identify patients aged 66 years or older with nonmetastatic gastric carcinoma diagnosed 1996 to 2005 who underwent resection. Exclusions included diagnosis at autopsy, no Medicare Part B, familial cancer syndrome, emergency surgery, and laparoscopic procedures. Epidurals were identified by Current Procedural Terminology codes. Treated recurrence was defined as chemotherapy greater than or equal to 16 months and/or radiation greater than or equal to 12 months after surgery. Recurrence was compared by conditional logistic regression. Survival was compared via marginal Cox proportional hazards regression model.

RESULTS

We identified 2745 patients, 766 of whom had epidural codes. Patients receiving epidurals were more likely to have regional disease, be white, and live in areas with relatively high socioeconomic status. Overall treated recurrence was 25.6% (27.5% epidural and 24.9% nonepidural). In the adjusted logistic regression, there was no difference in recurrence (odds ratio, 1.40; 95% confidence interval [CI], 0.96-2.05). Median survival did not differ: 28.1 months (95% CI, 24.8-32.3) in the epidural versus 27.4 months (95% CI, 24.8-30.0) in the nonepidural groups. The marginal Cox models showed no association between epidural use and mortality (adjusted hazard ratio, 0.93; 95% CI, 0.84-1.03).

CONCLUSIONS

There was no difference between groups regarding treated recurrence or survival. Whether this is true or simply a result of insufficient power is unclear. Prospective studies are needed to provide stronger evidence.

Anesthetic techniques and cancer recurrence after surgery

Many of the most common anesthetics are used in surgical oncology, yet effects on cancer cells are still not known. Anesthesia technique could differentially affect cancer recurrence in oncologic patients undergoing surgery, due to immunosuppression, stimulation of angiogenesis, and dissemination of residual cancer cells. Data support the use of intravenous anesthetics, such as propofol anesthesia, thanks to antitumoral protective effects inhibiting cyclooxygenase 2 and prostaglandins E2 in cancer cells, and stimulation of immunity response; a restriction in the use of volatile anesthetics; restriction in the use of opioids as they suppress humoral and cellular immunity, and their chronic use favors angiogenesis and development of metastases; use of locoregional anesthesia compared with general anesthesia, as locoregional appears to reduce cancer recurrence after surgery. However, these findings must be interpreted cautiously as there is no evidence that simple changes in the practice of anesthesia can have a positive impact on postsurgical survival of cancer patients.

Association between neuraxial analgesia, cancer progression, and mortality after radical prostatectomy: a large, retrospective matched cohort study

BACKGROUND

Systemic opioids are immunosuppressive, which could promote tumour recurrence. We, therefore, test the hypothesis that supplementing general anaesthesia with neuraxial analgesia improves long-term oncological outcomes in patients having radical prostatectomy for adenocarcinoma.

METHODS

Patients who had general anaesthesia with neuraxial analgesia (n=1642) were matched 1:1 based on age, surgical year, pathological stage, Gleason scores, and presence of lymph node disease with those who had general anaesthesia only. Medical records were reviewed. Outcomes of interest were systemic cancer progression, recurrence, prostate cancer mortality, and all-cause mortality. Data were analysed using stratified proportional hazards regression, the Kaplan-Meier method, and log-rank tests. The median follow-up was 9 yr.

RESULTS

After adjusting for comorbidities, positive surgical margins, and adjuvant hormonal and radiation therapies within 90 postoperative days, general anaesthesia only was associated with increased risk for systemic progression [hazard ratio (HR)=2.81, 95% confidence interval (CI) 1.31-6.05; P=0.008] and higher overall mortality (HR=1.32, 95% CI 1.00-1.74; P=0.047). Although not statistically significant, similar findings were observed for the outcome of prostate cancer deaths (adjusted HR=2.2, 95% CI 0.88-5.60; P=0.091).

CONCLUSIONS

This large retrospective analysis suggests a possible beneficial effect of regional anaesthetic techniques on oncological outcomes after prostate surgery for cancer; however, these findings need to be confirmed (or refuted) in randomized trials.

Immunosuppressive aspects of analgesics and sedatives used in mechanically ventilated patients: an underappreciated risk factor for the development of ventilator-associated pneumonia in critically ill patients

OBJECTIVE

To evaluate the evidence describing the immunosuppressive and pharmacokinetic properties of commonly used analgesic and sedation agents in critically ill patients.

DATA SOURCES

MEDLINE (January 1980-September 2013) was searched.

STUDY SELECTION AND DATA EXTRACTION

All in vitro and in vivo studies that evaluated the immune-modulating properties of analgesic and sedation agents commonly used in the critically ill were included. Full-text and abstract-only articles (noted) were included in this review. Inclusion criteria were met by 46 studies and were evaluated.

DATA SYNTHESIS

Analgesic and sedation agents have been shown to be immunosuppressive in a variety of models. In vitro models use a variety of immune cells to demonstrate the immunosuppressive properties of opioids, benzodiazepines, and to a lesser extent, propofol. In each case, animal studies provide more robust data supporting the concept that opioids, benzodiazepines, and propofol exhibit immunosuppressive activities ranging from innate to adaptive immune alterations. Human studies, though more limited, provide further support that these agents inhibit the immune response. In contrast, data have shown that dexmedetomidine may attenuate the immune system. Clinical trial data evaluating the immunosuppressive properties of these agents is limited.

CONCLUSIONS

Analgesic and sedation agents have clearly been shown to alter cellular function and other mediators of the immune system; yet the clinical impact remains to be fully elucidated. The mechanism by which sedation interruption reduces ventilator-associated pneumonia may in fact be a reduction in immunosuppressive effects. Studies linking the immune-modulating effects of analgesic and sedation agents in critically ill patients are needed.

Delirium in the intensive care unit

Delirium is a serious complication that commonly occurs in critically ill patients in the intensive care unit (ICU). Delirium is frequently unrecognized or missed despite its high incidence and prevalence, and leads to poor clinical outcomes and an increased cost by increasing morbidity, mortality, and hospital and ICU length of stay. Although its pathophysiology is poorly understood, numerous risk factors for delirium have been suggested. To improve clinical outcomes, it is crucial to perform preventive measures against delirium, to detect delirium early using valid and reliable screening tools, and to treat the underlying causes or hazard symptoms of delirium in a timely manner.

Epidural analgesia during open radical prostatectomy does not improve long-term cancer-related outcome: a retrospective study in patients with advanced prostate cancer

Background

A beneficial effect of regional anesthesia on cancer related outcome in various solid tumors has been proposed. The data on prostate cancer is conflicting and reports on long-term cancer specific survival are lacking.

Methods

In a retrospective, single-center study, outcomes of 148 consecutive patients with locally advanced prostate cancer pT3/4 who underwent retropubic radical prostatectomy (RRP) with general anesthesia combined with intra- and postoperative epidural analgesia (n=67) or with postoperative ketorolac-morphine analgesia (n=81) were reviewed. The median observation time was 14.00 years (range 10.87-17.75 yrs). Biochemical recurrence (BCR)-free, local and distant recurrence-free, cancer-specific, and overall survival were estimated using the Kaplan-Meier technique. Multivariate Cox proportional-hazards regression models were used to analyze clinicopathologic variables associated with disease progression and death.

Results

The survival estimates for BCR-free, local and distant recurrence-free, cancer-specific survival and overall survival did not differ between the two groups (P=0.64, P=0.75, P=0.18, P=0.32 and P=0.07). For both groups, higher preoperative PSA (hazard ratio (HR) 1.02, 95% confidence interval (CI) 1.01-1.02, P<0.0001), increased specimen Gleason score (HR 1.24, 95% CI 1.06-1.46, P=0.007) and positive nodal status (HR 1.66, 95% CI 1.03-2.67, P=0.04) were associated with higher risk of BCR. Increased specimen Gleason score predicted death from prostate cancer (HR 2.46, 95% CI 1.65-3.68, P<0.0001).

Conclusions

General anaesthesia combined with epidural analgesia did not reduce the risk of cancer progression or improve survival after RRP for prostate cancer in this group of patients at high risk for disease progression with a median observation time of 14.00 yrs.

Comparative effects of flurbiprofen and fentanyl on natural killer cell cytotoxicity, lymphocyte subsets and cytokine concentrations in post-surgical intensive care unit patients: prospective, randomized study

PURPOSE

The purpose of this study was to compare the effect of the long-term administration of flurbiprofen and fentanyl in the intensive care unit on natural killer cell cytotoxicity (NKCC), lymphocyte subsets and cytokine levels.

METHODS

In this prospective study, patients scheduled for at least 48 h sedation after neck surgery were randomly assigned to two groups called group N and group F. Group N patients were sedated with propofol and flurbiprofen after surgery (n = 12), while group F patients were sedated with propofol and fentanyl (n = 13). The NKCC, lymphocyte subsets, and plasma levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 were measured before and at the end of surgery, on postoperative day (POD) 1 and POD2.

RESULTS

The NKCC was significantly higher on POD1 in group N than in group F (14.5 ± 11.2 versus 6.3 ± 4.1%, p < 0.05), the difference between the groups disappearing on POD2. Lymphocyte subsets and plasma levels of cytokines were not significantly different between the two groups during the study period.

CONCLUSIONS

Transient suppressive effects on NKCC were observed in the fentanyl group as compared to the flurbiprofen group. This suggests that when choosing postoperative analgesics, physicians should bear in mind the potential immunosuppressive effects of these agents in patients requiring prolonged sedation in the intensive care unit.

[Influence of anesthesia procedure on malignant tumor outcome]

Malignant tumors are the second major cause of death in Germany. The essential therapy of operable cancer is surgical removal of primary tumors combined with adjuvant therapy. However, several consequences of surgery may promote metastasis, such as shedding of tumor cells into the circulation, decrease in tumor-induced antiangiogenesis factors, excessive release of growth factors for wound healing and suppression of immunity induced by surgical stress. In the last decade it has become clear that cell-mediated immunity controls the development of metastasis. Various perioperative factors, such as surgical stress, certain anesthetic and analgesic drugs and pain can suppress the patients' immune system perioperatively. On the other hand, by modifications of the anesthesia technique (e.g. regional anesthesia) and perioperative management to minimize immunosuppression, anesthesiologists can play a considerable role for a better outcome in patients having malignant tumors. Sufficient clinical evidence is not yet available to prove or disprove the hypothesis that anesthesia practice can improve cancer prognosis. Despite difficulties in study design, several prospective randomized trials are currently running and the results are awaited to elucidate this topic.

Use of opioids or benzodiazepines and risk of pneumonia in older adults: a population-based case-control study

OBJECTIVES

To examine whether use of opioids or benzodiazepines is associated with risk of community-acquired pneumonia in older adults.

DESIGN

Population-based case-control study.

SETTING

An integrated healthcare delivery system.

PARTICIPANTS

Community-dwelling, immunocompetent adults aged 65 to 94 from 2000 to 2003. Presumptive pneumonia cases were identified from health plan automated data and validated through medical record review. Two controls were selected for each case with pneumonia, matched on age, sex, and calendar year.

MEASUREMENTS

Information about opioid and benzodiazepine use came from computerized pharmacy data. Information on covariates including comorbid illnesses and functional and cognitive status came from medical record review and electronic health data.

RESULTS

One thousand thirty-nine validated cases of pneumonia and 2,022 matched controls were identified. One hundred forty-four (13.9%) cases and 161 (8.0%) controls used prescription opioids (adjusted odds ratio (OR) = 1.38, 95% confidence interval (CI) = 1.08-1.76 vs nonuse). Risk was highest for opioids categorized as immunosuppressive based on immunological studies (OR = 1.88, 95% CI = 1.26-1.79 vs nonuse), whereas for nonimmunosuppressive opioids the OR was 1.23 (95% CI = 0.89-1.69). Risk was highest in the first 14 days of use (OR = 3.24, 95% CI = 1.64-6.39 vs nonuse). For long-acting opioids, the OR was 3.43 (95% CI = 1.44-8.21) versus nonuse, whereas for short-acting opioids, it was 1.27 (95% CI = 0.98-1.64). No greater risk was seen for current benzodiazepine use compared to nonuse (OR = 1.08, 95% CI = 0.80-1.47).

CONCLUSION

Use of opioids but not benzodiazepines was associated with pneumonia risk. The differences in risk seen for different opioid regimens warrant further study.

Morphine use in cancer surgery

Morphine is the core of perioperative pain management. However, when it comes to cancer surgery the possibility that this drug might affect tumor recurrence and metastasis has raised concerns. The results of two recent retrospective clinical trials indicated that regional anesthesia/analgesia might be beneficial in prostate and breast cancer surgery. It was proposed that morphine could be responsible for the higher recurrence and mortality rate observed in the general anesthesia/opioid analgesia groups. Nevertheless, the results of several other retrospective studies and one randomized prospective trial failed to confirm any advantage for regional anesthesia/analgesia over general anesthesia and opioid analgesia. Moreover laboratory data on the effect of morphine on cancer are contradictory, ranging from tumor-promoting to anti-tumor effects. Considering that surgical stress and pain promote the recurrence and spread of cancer, choosing a proper analgesic strategy is of high significance. Although the question of whether morphine causes any harm to cancer patients remains unanswered, alternative analgesic regimens could be used concomitant to or instead of morphine to limit its potential adverse effects.

Morphine and tumor growth and metastasis

Morphine is an analgesic widely used to alleviate cancer pain. In addition, the perioperative management of pain in cancer surgery patients most often includes opioids. However, there are reports that these drugs may alter cancer recurrence or metastasis. Several mechanisms have been proposed, such as the modulation of the immune response or cellular pathways that control the survival and migratory behavior of cancer cells. The published literature, however, presents some discrepancies, with reports suggesting that opioids may either promote or prevent the spread of cancer. It is of great importance to determine whether opioids, in particular the most widely used, morphine, may increase the risk of metastasis when used in cancer surgery. This review examines the available data on the effects of morphine which influence cancer metastasis or recurrence, including immunomodulation, tumor cell aggressiveness, and angiogenesis, with special emphasis on recently published clinical and laboratory based studies. We further discuss the parameters that may explain the difference between reports on the effects of morphine on cancer.