The effect of different anesthetics on tumor cytotoxicity by natural killer cells

Effects of anesthesia with sevoflurane on outcome parameters in murine experimental studies

PURPOSE

Multiple murine studies modelling the immuno-pathophysiological consequences of trauma, shock, burn or sepsis were performed during the last decades. Almost every animal model requires anesthesia for practical and ethical reasons. Furthermore, often, corresponding control groups involve untreated animals without or with a limited exposure to anesthetics. However, the influences of anesthetic drugs on immuno-pathophysiological reactions remain insufficiently investigated. Therefore, we aimed to closer characterize the anesthetic impact exemplified by sevoflurane on the organ performance in mice and thereby investigate the influence of anesthesia itself on major outcome parameters in animal studies.

METHODS

C57/BL6 mice were subjected either to 270 min of sevoflurane narcosis or directly euthanized. Plasma, BAL-fluids, lungs, kidneys, liver and intestine were collected and examined for immunological, functional and morphological changes.

RESULTS

Systemic levels of the cytokine keratinocyte chemoattractant (KC) were raised in the narcosis group, while concentrations of high mobility group box protein 1 (HMGB-1) as a major inflammatory marker were reduced. In the lungs, levels of HMGB-1 and interleukin 6 (IL-6) were reduced. In contrast, systemic concentrations of intestinal fatty acid binding-protein (i-FABP) as an intestinal damage marker were elevated. Furthermore, liver-type fatty acid binding-protein (L-FABP) levels were lower in the narcosis animals, and inflammatory markers were reduced in liver tissues. Anesthesia also ameliorated the inflammatory reaction in renal tissues, while plasma levels of urea and creatinine were elevated, reflecting either dehydration and/or impaired renal function.

CONCLUSION

As anesthesia with sevoflurane exhibited distinct effects in different organs, it is difficult to predict its specific impact on targets of interest in in vivo studies. Therefore, further studies are required to clarify the effects of different anesthetic drugs. Overall, the inclusion of a control group subjected to the same anesthesia protocol as the experimental groups of interest seems helpful to precisely define the inherent impact of the anesthetic when investigating immuno-pathophysiologic conditions in vivo.

Mechanism of isoflurane‑mediated breast cancer growth in vivo

Use of volatile anesthetics is associated with worse outcome following tumor resection surgery compared with the use of intravenous anesthetics. However, the underlying mechanism has not been clearly delineated yet in vivo. The EO771 cell-based congenic breast cancer model was used in the present study. Isoflurane directly binds to and inhibits two adhesion molecules, leukocyte function-associated antigen-1 (LFA-1) and macrophage-1 antigen (Mac-1). Similarly, exposure to sevoflurane, another volatile anesthetic and LFA-1 inhibitor, is associated with an increase in breast cancer size compared with non-exposure. Thus, the present study first examined the role of LFA-1 and Mac-1 in the EO771 breast cancer model. Both LFA-1 deficiency and inhibition enhanced tumor growth, which was supported by cytokine and eicosanoid data profiles. By contrast, Mac-1 deficiency did not affect tumor growth. The exposure to isoflurane and sevoflurane was associated with an increase in breast cancer size compared with non-exposure. These data suggested that isoflurane enhanced tumor growth by interacting with LFA-1. Isoflurane exposure did not affect tumor growth in LFA-1-deficient mice. In summary, the present data showed that LFA-1 deficiency facilitated breast cancer growth, and isoflurane, an LFA-1 inhibitor, also increased breast cancer growth.

Effects of anesthesia on long-term survival in cancer surgery: A systematic review and meta-analysis

Backgrounds

The association between anesthesia and long-term oncological outcome after cancer surgery remains controversial. This study aimed to investigate the effect of propofol-based anesthesia and inhalation anesthesia on long-term survival in cancer surgery.

Methods

A comprehensive literature search was performed in PubMed, Medline, Embase, and the Cochrane Library until November 15, 2023. The outcomes included overall survival (OS) and recurrence-free survival (RFS). The hazard ratio (HR) and 95 % confidence interval (CI) were calculated with a random-effects model.

Results

We included forty-two retrospective cohort studies and two randomized controlled trials (RCTs) with 686,923 patients. Propofol-based anesthesia was associated with improved OS (HR = 0.82, 95 % CI:0.76-0.88, P < 0.00001) and RFS (HR = 0.80, 95 % CI:0.73-0.88, P < 0.00001) than inhalation anesthesia after cancer surgery. However, these positive results were only observed in single-center studies (OS: HR = 0.76, 95 % CI:0.68-0.84, P < 0.00001; RFS: HR = 0.76, 95 % CI:0.66-0.87, P < 0.0001), but not in multicenter studies (OS: HR = 0.98, 95 % CI:0.94-1.03, P = 0.51; RFS: HR = 0.95, 95 % CI:0.87-1.04, P = 0.26). The subgroup analysis revealed that propofol-based anesthesia provided OS and RFS advantages in hepatobiliary cancer (OS: HR = 0.58, 95 % CI:0.40-0.86, P = 0.005; RFS: HR = 0.62, 95 % CI:0.44-0.86, P = 0.005), gynecological cancer (OS: HR = 0.52, 95 % CI:0.33-0.81, P = 0.004; RFS: HR = 0.51, 95 % CI:0.36-0.72, P = 0.0001), and osteosarcoma (OS: HR = 0.30, 95 % CI:0.11-0.81, P = 0.02; RFS: HR = 0.32, 95 % CI:0.14-0.75, P = 0.008) surgeries.

Conclusion

Propofol-based anesthesia may be associated with improved OS and RFS than inhalation anesthesia in some cancer surgeries. Considering the inherent weaknesses of retrospective designs and the strong publication bias, our findings should be interpreted with caution. Well-designed multicenter RCTs are still urgent to further confirm these findings.

Antibody dependent cell-mediated cytotoxicity selection pressure induces diverse mechanisms of resistance

Targeted monoclonal antibody therapy has emerged as a powerful therapeutic strategy for cancer. However, only a minority of patients have durable responses and the development of resistance remains a major clinical obstacle. Antibody-dependent cell-mediated cytotoxicity (ADCC) represents a crucial therapeutic mechanism of action; however, few studies have explored ADCC resistance. Using multiple in vitro models of ADCC selection pressure, we have uncovered both shared and distinct resistance mechanisms. Persistent ADCC selection pressure yielded ADCC-resistant cells that are characterized by a loss of NK cell conjugation and this shared resistance phenotype is associated with cell-line dependent modulation of cell surface proteins that contribute to immune synapse formation and NK cell function. We employed single-cell RNA sequencing and proteomic screens to interrogate molecular mechanisms of resistance. We demonstrate that ADCC resistance involves upregulation of interferon/STAT1 and DNA damage response signaling as well as activation of the immunoproteasome. Here, we identify pathways that modulate ADCC sensitivity and report strategies to enhance ADCC-mediated elimination of cancer cells. ADCC resistance could not be reversed with combinatorial treatment approaches. Hence, our findings indicate that tumor cells utilize multiple strategies to inhibit NK cell mediated-ADCC. Future research and development of NK cell-based immunotherapies must incorporate plans to address or potentially prevent the induction of resistance.

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.

LFA-1 knockout inhibited the tumor growth and is correlated with treg cells

Cancer immunotherapy has been proven to be clinically effective in multiple types of cancers. Lymphocyte function-associated antigen 1 (LFA-1), a member of the integrin family of adhesion molecules, is expressed mainly on αβ T cells. LFA-1 is associated with tumor immune responses, but its exact mechanism remains unknown. Here, two kinds of mice tumor model of LFA-1 knockout (LFA-1-/-) mice bearing subcutaneous tumor and Apc Min/+;LFA-1-/- mice were used to confirm that LFA-1 knockout resulted in inhibition of tumor growth. Furthermore, it also demonstrated that the numbers of regulatory T cells (Treg cells) in the spleen, blood, mesenteric lymph nodes were decreased in LFA-1-/- mice, and the numbers of Treg cells in mesenteric lymph nodes were also decreased in Apc Min/+;LFA-1-/- mice compared with Apc Min/+ mice. LFA-1 inhibitor (BIRT377) was administered to subcutaneous tumor-bearing LFA-1+/+ mice, and the results showed that the tumor growth was inhibited and the number of Treg cells was reduced. The analysis of TIMER tumor database indicated that LFA-1 expression is positively associated with Treg cells and TNM stage. Conclusively, this suggests that LFA-1 knockout would inhibit tumor growth and is correlated with Treg cells. LFA-1 may be one potential target for cancer immunotherapy. Video Abstract.

Total intravenous anesthesia versus inhalation anesthesia: how do outcomes compare?

RECENT FINDINGS

Surgical procedures that involve general anesthesia are performed with either volatile anesthetics or propofol-based total intravenous anesthesia. Both techniques are safe and provide appropriate conditions for surgery. Despite being a well established anesthetic, the use of propofol-based total intravenous anesthesia (TIVA) remains low. Possible explanations include the perceived increase risk of awareness, lack of target controlled infusion devices, increased turnover time for device set up and individual preference.

SUMMARY

There are some scenarios where patients could potentially benefit from propofol-based TIVA rather than a volatile anesthetic (e.g. postoperative nausea and vomiting) and some other clinical scenarios where the use of propofol-based anesthesia remains controversial since the strength of the evidence remains low.

PURPOSE

In this review we will summarize the clinical evidence comparing the effect of propofol-based TIVA and volatile anesthetic on postoperative outcomes such as postoperative nausea and vomiting, postoperative pain, quality of recovery, postoperative cognitive dysfunction and cancer outcomes.

Long-term survival in older patients given propofol or sevoflurane anaesthesia for major cancer surgery: follow-up of a multicentre randomised trial

BACKGROUND

Experimental evidence indicates that i.v. anaesthesia might reduce cancer recurrence compared with volatile anaesthesia, but clinical information is observational only. We therefore tested the primary hypothesis that propofol-based anaesthesia improves survival over 3 or more years after potentially curative major cancer surgery.

METHODS

This was a long-term follow-up of a multicentre randomised trial in 14 tertiary hospitals in China. We enrolled 1228 patients aged 65-90 yr who were scheduled for major cancer surgery. They were randomised to either propofol-based i.v. anaesthesia or to sevoflurane-based inhalational anaesthesia. The primary endpoint was overall survival after surgery. Secondary endpoints included recurrence-free and event-free survival.

RESULTS

Amongst subjects randomised, 1195 (mean age 72 yr; 773 [65%] male) were included in the modified intention-to-treat analysis. At the end of follow-up (median 43 months), there were 188 deaths amongst 598 patients (31%) assigned to propofol-based anaesthesia compared with 175 deaths amongst 597 patients (29%) assigned to sevoflurane-based anaesthesia; adjusted hazard ratio 1.02; 95% confidence interval (CI): 0.83-1.26; P=0.834. Recurrence-free survival was 223/598 (37%) in patients given propofol anaesthesia vs 206/597 (35%) given sevoflurane anaesthesia; adjusted hazard ratio 1.07; 95% CI: 0.89-1.30; P=0.465. Event-free survival was 294/598 (49%) in patients given propofol anaesthesia vs 274/597 (46%) given sevoflurane anaesthesia; adjusted hazard ratio 1.09; 95% CI 0.93 to 1.29; P=0.298.

CONCLUSIONS

Long-term survival after major cancer surgery was similar with i.v. and volatile anaesthesia. Propofol-based iv. anaesthesia should not be used for cancer surgery with the expectation that it will improve overall or cancer-specific survival.

CLINICAL TRIAL REGISTRATIONS

ChiCTR-IPR-15006209; NCT02660411.

Effect of surgical pleth index-guided remifentanil administration on perioperative outcomes in elderly patients: a prospective randomized controlled trial

BACKGROUND

During general anesthesia, the surgical pleth index (SPI) monitors nociception. The evidence of SPI in the elderly remains scarce. We aimed to investigate whether there is a difference in perioperative outcomes following intraoperative opioid administration according to the surgical pleth index (SPI) value versus hemodynamic parameters (heart rate or blood pressure) in elderly patients.

METHODS

Patients aged 65-90 years who underwent laparoscopic colorectal cancer surgery under sevoflurane/remifentanil anesthesia were randomized to receive remifentanil guided by SPI (SPI group) or conventional clinical judgment based on hemodynamic parameters (conventional group). The primary endpoint was intraoperative remifentanil consumption. Secondary endpoints were intraoperative hemodynamic instability, pain score, fentanyl consumption and delirium in the post-anesthesia care unit (PACU), and perioperative changes in interleukin-6 and natural killer (NK) cell activity.

RESULTS

Seventy-five patients (38, SPI; 37, conventional) were included in the study. The SPI group consumed significantly more remifentanil intraoperatively than the conventional group (mean ± SD, 0.13 ± 0.05 vs. 0.06 ± 0.04 μg/kg/min, P < 0.001). Intraoperative hypertension and tachycardia were more common in the conventional group than in the SPI group. Pain score in the PACU (P = 0.013) and the incidence of delirium in the PACU were significantly lower in the SPI group than the conventional group (5.2% vs. 24.3%, P = 0.02). There was no significant difference in NK cell activity and interleukin-6 level.

CONCLUSIONS

In the elderly patients, SPI-guided analgesia provided appropriate analgesia with sufficient intraoperative remifentanil consumption, lower incidence of hypertension/ tachycardia events, and a lower incidence of delirium in the PACU than the conventional analgesia. However, SPI-guided analgesia may not prevent perioperative immune system deterioration.

TRIAL REGISTRATION

The randomized controlled trial was retrospectively registered in the UMIN Clinical Trials Registry (trial number: UMIN000048351; date of registration: 12/07/2022).

Long-term effect of anesthesia choice on patients with hepatocellular carcinoma undergoing open liver resection

Clinical and experimental evidence suggested that anesthesia choice can influence cancer progression and patients' outcomes by modulating tumor microenvironment and tumorigenic pathways. Curative resection is the mainstay of therapy for hepatocellular carcinoma (HCC), which is an intractable disease due to high recurrence and poor prognosis. However, different anesthetics may play different roles in alleviating surgery-induced stress response and inflammatory cytokines release that are considered to be closely associated with proliferation, invasion and metastasis of tumor cells. Propofol, sevoflurane, non-steroidal anti-inflammatory drugs and local anesthetics have shown to exert anti-tumor effect on HCC mainly through regulating microRNAs or signaling pathways, while other inhalational agents, dexmedetomidine and opioids have the potential to promote tumor growth. In terms of anesthetic methods and analgesia strategies, propofol based total intravenous anesthesia and thoracic epidural analgesia could be preferred for HCC patients undergoing open liver resection rather than inhalational anesthesia. Local anesthesia techniques have great potential to attenuate perioperative stress response, hence they may contribute to more favorable outcomes. This review summarized the relations between different anesthesia choices and HCC patients' long-term outcomes as well as their underlying mechanisms. Due to the complexity of molecules interactions and signaling pathways, further studies are warranted to confirm these results so as to optimize anesthesia strategy for HCC patients.

Immunomodulatory roles of propofol and sevoflurane in murine models of breast cancer

BACKGROUND

Anesthetics are emerging regulators of cancer progression. Here we aim to explore the immunomodulatory roles of two common anesthetics, propofol and sevoflurane in breast cancer progression.

METHODS

On murine 4T1 breast cancer models, we isolated immune cells from peripheral blood after treatment with propofol and sevoflurane during tumor resection. The CD3, CD4 and CD8 expression of these immune cells were compared using flow cytometry to determine which immune cells were prominently affected by propofol and sevoflurane. Serum cytokine levels were determined using enzyme-linked immunosorbent assay (ELISA). Metastases in lung and liver tissues were counted. In MDA-MB-231 tumor models, the cell count of immune cells was determined. The cytotoxicity of T cells and natural killing cells in co-culture after propofol and sevoflurane treatment were determined using the LDH assay.

RESULTS

In the 4T1 breast cancer model, T-lymphocytes showed significant cell count reduction. TNF-α was significantly upregulated at 3 h and 24 h after treatment, while IL-2 and IFN-γ showed transient upregulation at 3 h after treatment. Propofol and sevoflurane increased the number of metastases in the lung and liver after primary tumor resection. In the MDA-MB-231 tumor model, CD3 and CD4 cells were also prominently reduced by propofol and sevoflurane treatment. In vitro, the proliferation and cell-killing activity of T cells and NK cells were also attenuated.

CONCLUSIONS

Propofol and sevoflurane had significant effects in modulating cancer progression through their immunosuppressive role. The proliferation and killing activity of anti-tumor immune cells can be suppressed by propofol and sevoflurane.

Potential influence of anaesthesia techniques on the recurrence and progression after resection of non-muscle-invasive bladder cancer: a propensity score-matched analysis

Background

The non-muscle-invasive bladder cancer is a common malignancy of the urinary system. Many patients relapse after transurethral resection surgery. Different anaesthesia techniques may influence a patient’s immune system during the perioperative time. In this study, we examined the effects of different anaesthesia techniques on the prognosis of primary non-muscle-invasive bladder cancer after transurethral resection surgery.

Methods

In the period 2008 to 2017, a total of 926 patients suffered primary non-muscle-invasive bladder and underwent transurethral resection of bladder tumour surgery for the first time. These patients were divided into two groups according to the techniques that were used. There were 662 patients in the general anaesthesia group, who received propofol, opioid drugs (fentanyl family), non-depolarizing muscle relaxants, and sevoflurane, and 264 patients in the epidural anaesthesia group, who had an epidural catheter placed in the L2-L3 or L3-L4 interspace with a combination of lidocaine and ropivacaine or bupivacaine. We analyzed the influence factors that might affect prognosis and compared the recurrence-free survival time and the progression between the two groups.

Results

The differences between the two groups in recurrence rate and progression rate were not statistically significant. Progression-free survival time of the epidural anaesthesia group was longer. Multivariate regression analysis showed that anaesthesia techniques were not independent influencing factors for recurrence and progression.

Conclusions

It was not found that anaesthesia techniques affected the recurrence or progression of patients with primary non-muscle-invasive bladder cancer after transurethral resection of bladder tumour.

Anesthesia and cancer recurrence: an overview

Several perioperative factors are responsible for the dysregulation or suppression of the immune system with a possible impact on cancer cell growth and the development of new metastasis. These factors have the potential to directly suppress the immune system and activate hypothalamic-pituitary-adrenal axis and the sympathetic nervous system with a consequent further immunosuppressive effect.Anesthetics and analgesics used during the perioperative period may modulate the innate and adaptive immune system, inflammatory system, and angiogenesis, with a possible impact on cancer recurrence and long-term outcome. Even if the current data are controversial and contrasting, it is crucial to increase awareness about this topic among healthcare professionals for a future better and conscious choice of anesthetic techniques.In this article, we aimed to provide an overview regarding the relationship between anesthesia and cancer recurrence. We reviewed the effects of surgery, perioperative factors, and anesthetic agents on tumor cell survival and tumor recurrence.

Drug Repurposing: The Mechanisms and Signaling Pathways of Anti-Cancer Effects of Anesthetics

Cancer is one of the leading causes of death worldwide. There are only limited treatment strategies that can be applied to treat cancer, including surgical resection, chemotherapy, and radiotherapy, but these have only limited effectiveness. Developing a new drug for cancer therapy is protracted, costly, and inefficient. Recently, drug repurposing has become a rising research field to provide new meaning for an old drug. By searching a drug repurposing database ReDO_DB, a brief list of anesthetic/sedative drugs, such as haloperidol, ketamine, lidocaine, midazolam, propofol, and valproic acid, are shown to possess anti-cancer properties. Therefore, in the current review, we will provide a general overview of the anti-cancer mechanisms of these anesthetic/sedative drugs and explore the potential underlying signaling pathways and clinical application of these drugs applied individually or in combination with other anti-cancer agents.

Long-term oncological outcomes after oral cancer surgery using propofol-based total intravenous anesthesia versus sevoflurane-based inhalation anesthesia: A retrospective cohort study

Background

Previous studies have shown that the anesthetic technique may influence long-term outcomes after cancer surgery. However, the association between the anesthetic technique and long-term oncological outcomes after oral cancer surgery remains unclear. Therefore, we conducted this study to address this gap.

Methods

We reviewed the electronic medical records of patients who underwent elective oral cancer surgery between January 2014 and December 2015. The patients were grouped based on the anesthesia maintenance: either propofol or sevoflurane. Propensity score matching in a 1:1 ratio was performed to deal with the potential confounding effects of baseline characteristics. Univariate and multivariate Cox regression analyses were performed to compare hazard ratios (HRs) and identify the risk factors for death and recurrence. Survival analysis was performed using the Kaplan–Meier method, and survival curves were constructed from the date of surgery to death.

Results

In total, 1347 patients were eligible for analysis, with 343 and 1004 patients in the propofol and sevoflurane groups, respectively. After propensity score matching, 302 patients remained in each group. Kaplan–Meier survival curves demonstrated the 5-year overall and recurrence-free survival rates of 59.3% and 56.0% and 62.7% and 56.5% in the propofol and sevoflurane groups, respectively. There was no significant difference in overall survival or recurrence-free survival between the groups. The multivariate Cox analysis verified this conclusion with HRs of 1.10 and 1.11 for overall survival and recurrence-free survival, respectively, in the sevoflurane group. Older age, advanced tumor-node-metastasis (TNM) stage, and American Society of Anesthesiologists class III were associated with poor overall survival. Patients with advanced TNM stage and poorly differentiated squamous cell carcinoma had a higher recurrence risk than their counterparts.

Conclusion

The overall and recurrence-free survival rates were similar between propofol-based intravenous anesthesia and sevoflurane volatile anesthesia in patients who underwent oral cancer surgery.

Application of Anesthetics in Cancer Patients: Reviewing Current Existing Link With Tumor Recurrence

Surgery remains the most effective cancer treatment, but residual disease in the form of scattered micro-metastases and tumor cells is usually unavoidable. Whether minimal residual disease results in clinical metastases is a function of host defense and tumor survival and growth. The much interesting intersection of anesthesiology and immunology has drawn increasing clinical interest, particularly, the existing concern of the possibility that the perioperative and intraoperative anesthetic care of the surgical oncology patient could meaningfully influence tumor recurrence. This paper examines current data, including recent large clinical trials to determine whether the current level of evidence warrants a change in practice. Available pieces of evidence from clinical studies are particularly limited, largely retrospective, smaller sample size, and often contradictory, causing several questions and providing few answers. Recent randomized controlled clinical trials, including the largest study (NCT00418457), report no difference in cancer recurrence between regional and general anesthesia after potentially curative surgery. Until further evidence strongly implicates anesthesia in future clinical trials, clinicians may continue to choose the optimum anesthetic-analgesic agents and techniques in consultation with their cancer patients, based on their expertise and current best practice.

Effect of Inhalation Anesthetics on Tumor Metastasis

Many factors affect the prognosis of patients undergoing tumor surgery, and anesthesia is one of the potential influencing factors. In general anesthesia, inhalation anesthesia is widely used in the clinic because of its strong curative effect and high controllability. However, the effect of inhalation anesthetics on the tumor is still controversial. More and more research has proved that inhalation anesthetics can intervene in local recurrence and distant metastasis of tumor by acting on tumor biological behavior, immune response, and gene regulation. In this paper, we reviewed the research progress of diverse inhalation anesthetics promoting or inhibiting cancer in the critical events of tumor recurrence and metastasis, and compared the effects of inhalation anesthetics on patients' prognosis in clinical studies, to provide theoretical reference for anesthesia management of patients undergoing tumor surgery.

Anesthesia Techniques and Long-Term Oncological Outcomes

Despite advances in cancer treatments, surgery remains one of the most important therapies for solid tumors. Unfortunately, surgery promotes angiogenesis, shedding of cancer cells into the circulation and suppresses anti-tumor immunity. Together this increases the risk of tumor metastasis, accelerated growth of pre-existing micro-metastasis and cancer recurrence. It was theorized that regional anesthesia could influence long-term outcomes after cancer surgery, however new clinical evidence demonstrates that the anesthesia technique has little influence in oncologic outcomes. Several randomized controlled trials are in progress and may provide a better understanding on how volatile and intravenous hypnotics impact cancer progression. The purpose of this review is to summarize the effect of the anesthesia techniques on the immune system and tumor microenvironment (TME) as well as to summarize the clinical evidence of anesthesia techniques on cancer outcomes.

Anesthetic care influences long-term outcomes: What is the evidence?

Despite advances in cancer therapy surgery remains one of the most important treatments for solid tumors; however, even with the development of better and less invasive surgical techniques, surgery is characterized by the increased risk of tumor metastasis, accelerated growth of pre-existing micrometastasis and cancer recurrence. Total intravenous anesthesia (TIVA) and regional anesthesia have been proposed to improve long-term outcomes after cancer surgery by different mechanisms, including attenuation of the neuroendocrine response, immunosuppression, decreased opioid requirements (opioids promote angiogenesis and tumor growth) and avoidance of volatile inhalational agents. Much of the data that support these ideas originate from laboratory studies, while there is no clear consensus from the retrospective cohort studies to date. Several randomized controlled trials (RCTs) are in progress and may provide a better understanding regarding the role of the anesthesiologist in cancer surgery. The purpose of this review is to summarize the experimental and human data regarding the effect of anesthesia agents and anesthesia techniques on cancer outcomes.

Postoperative Natural Killer Cell Dysfunction: The Prime Suspect in the Case of Metastasis Following Curative Cancer Surgery

Surgical resection is the foundation for the curative treatment of solid tumors. However, metastatic recurrence due to the difficulty in eradicating micrometastases remain a feared outcome. Paradoxically, despite the beneficial effects of surgical removal of the primary tumor, the physiological stress resulting from surgical trauma serves to promote cancer recurrence and metastasis. The postoperative environment suppresses critical anti-tumor immune effector cells, including Natural Killer (NK) cells. The literature suggests that NK cells are critical mediators in the formation of metastases immediately following surgery. The following review will highlight the mechanisms that promote the formation of micrometastases by directly or indirectly inducing NK cell suppression following surgery. These include tissue hypoxia, neuroendocrine activation, hypercoagulation, the pro-inflammatory phase, and the anti-inflammatory phase. Perioperative therapeutic strategies designed to prevent or reverse NK cell dysfunction will also be examined for their potential to improve cancer outcomes by preventing surgery-induced metastases.

The Role of General Anesthetic Drug Selection in Cancer Outcome

Cancer remains to be the leading cause of death globally. Surgery is a mainstay treatment for solid tumors. Thus, it is critical to optimize perioperative care. Anesthesia is a requisite component for surgical tumor resection, and general anesthesia is given in the vast majority of tumor resection cases. Because anesthetics are growingly recognized as immunomodulators, it is critical to optimize anesthetic regimens for cancer surgery if the selection can affect outcomes. Here, we reviewed the role of volatile and intravenous anesthesia used for cancer surgery in cancer recurrence.

Impact of anesthetics on oncogenic signaling network: a review on propofol and isoflurane

Propofol as an intravenous anesthetic and isoflurane as an inhalational/volatile anesthetic continue to be an important part of surgical anesthetic interventions worldwide. The impact of these anesthetics on tumor progression, immune modulation, and survival rates of cancer patients has been widely investigated. Although most of the preclinical studies have provided a beneficial effect of propofol over isoflurane or other volatile anesthetics, several investigations have shown contradictory results, which warrant more preclinical and clinical studies. Propofol mostly exhibits antitumor properties, whereas isoflurane being a cost-effective anesthetic is frequently used. However, isoflurane has been also reported with protumorigenic activity. This review provides an overall perspective on the network of signaling pathways that may modulate several steps of tumor progression from inflammation, immunomodulation, epithelial-mesenchymal transition (EMT) to invasion, metastasis, angiogenesis, and cancer stemness and extracellular vesicles along with chemotherapeutic applications and clinical status of these anesthetics. A clear understanding of the mechanistic viewpoints of these anesthetics may pave the way for more prospective clinical trials with the ultimate goal of obtaining a safe and optimal anesthetic intervention that would prevent cancer recurrence and may influence better postoperative survival.

Influence of scalp block on oncological outcomes of high-grade glioma in adult patients with and without isocitrate dehydrogenase-1 mutation

High-grade gliomas are notorious for a high recurrence rate even after curative resection surgery. Studies regarding the influence of scalp block on high-grade gliomas have been inconclusive, possibly because the condition's most important genetic mutation profile, namely the isocitrate dehydrogenase 1 (IDH1) mutation, had not been analyzed. Therefore, we conducted a single-center study including patients with high-grade glioma who underwent tumor resection between January 2014 and December 2019. Kaplan-Meier survival analysis revealed that scalp block was associated with longer progression-free survival (PFS; 15.17 vs. 10.77 months, p = 0.0018), as was the IDH1 mutation (37.37 vs. 10.90 months, p = 0.0149). Multivariate Cox regression analysis revealed that scalp block (hazard ratio: 0.436, 95% confidence interval: 0.236-0.807, p = 0.0082), gross total resection (hazard ratio: 0.405, 95% confidence interval: 0.227-0.721, p = 0.0021), and IDH1 mutation (hazard ratio: 0.304, 95% confidence interval: 0.118-0.784, p = 0.0138) were associated with better PFS. Our results demonstrate that application of scalp block, regardless of IDH1 profile, is an independent factor associated with longer PFS for patients with high-grade glioma.

The Effects of Anesthetics and Perioperative Medications on Immune Function: A Narrative Review

Preclinical and clinical studies have sought to better understand the effect of anesthetic agents, both volatile and intravenous, and perioperative adjuvant medications on immune function. The immune system has evolved to incorporate both innate and adaptive components, which are delicately interwoven and essential for host defense from pathogens and malignancy. This review summarizes the complex and nuanced relationship that exists between each anesthetic agent or perioperative adjuvant medication studied and innate and adaptive immune function with resultant clinical implications. The most commonly used anesthetic agents were chosen for review including volatile agents (sevoflurane, isoflurane, desflurane, and halothane), intravenous agents (propofol, ketamine, etomidate, and dexmedetomidine), and perioperative adjuvant medications (benzodiazepines, opioids, nonsteroidal anti-inflammatory drugs [NSAIDs], and local anesthetic agents). Patients who undergo surgery experience varying combinations of the aforementioned anesthetic agents and adjuncts, depending on the type of surgery and their comorbidities. Each has unique effects on immunity, which may be more or less ideal depending on the clinical situation. Further study is needed to better understand the clinical effects of these relationships so that patient-specific strategies can be developed to improve surgical outcomes.

Perioperative changes in the plasma metabolome of patients receiving general anesthesia for pancreatic cancer surgery

Background: Modern anesthesia strives to offer personalized concepts to meet the patient’s individual needs in sight of clinical outcome. Still, little is known about the impact of anesthesia on the plasma metabolome, although many metabolites have been shown to modulate the function of various immune cells, making it particularly interesting in the context of oncological surgery. In this study longitudinal dynamics in the plasma metabolome during general anesthesia in patients undergoing pancreatic surgery were analyzed.

Materials and Methods: Prospective, observational study with 10 patients diagnosed with pancreatic (pre-) malignancy and subjected to elective resection surgery under general anesthesia. Plasma metabolites (n = 630) were quantified at eight consecutive perioperative timepoints using mass spectrometry-based targeted metabolomics.

Results: 39 metabolites significantly changed during the perioperative period. Tryptophan concentrations decreased by 45% with the maximum decrease after anesthesia induction (p = 6.24E-07), while taurine synthesis increased (p = 1.46E-04). Triacylglycerides and lysophosphatidylcholines were significantly reduced with increased liberation of free monounsaturated fatty acids (p = 0.03). Carnitine levels decreased significantly (p = 9.30E-04).

Conclusions: The major finding of this study was perioperative tryptophan depletion and increased taurine synthesis. Both are essential for immune cell function and are therefore of significant interest for perioperative management. Further studies are needed to identify influencing anesthetic factors.

The immunomodulatory mechanism of dexmedetomidine

Dexmedetomidine has been increasingly introduced into the perioperative care of surgical patients. Because a subset of anesthetics/sedatives are immunomodulatory, it is critical to understand the role of dexmedetomidine in our host immune functions. Here we reviewed the role of dexmedetomidine in different immune cells. We also reviewed published clinical articles that described the role of dexmedetomidine in organ injury, cancer surgery, and infection. In animal studies, dexmedetomidine attenuated organ injury. In clinical studies, dexmedetomidine was associated with an improvement in outcomes in cardiac surgery and transplant surgery. However, there is a paucity in research examining how dexmedetomidine is associated with these outcomes. Further studies are needed to understand its clinical application from immunological standpoints.

The Characterization of Postoperative Mechanical Respiratory Requirement in Neonates and Infants Undergoing Cardiac Surgery on Cardiopulmonary Bypass in a Single Tertiary Institution

OBJECTIVES

Although neonates and infants undergoing cardiac surgery on cardiopulmonary bypass (CPB) are at high risk of developing perioperative morbidity and mortality, including lung injury, the intraoperative profile of lung injury in this cohort is not well-described. Given that the postoperative course of patients in the pediatric cardiac surgical arena has become increasingly expedited, the objective of this study was to characterize the profiles of postoperative mechanical ventilatory support in neonates and infants undergoing cardiac surgery on CPB and to examine the characteristics of lung mechanics and lung injury in this patient population who are potentially amendable to early postoperative recovery in a single tertiary pediatric institution.

DESIGN

A retrospective data analysis of neonates and infants who underwent cardiac surgery on cardiopulmonary bypass.

SETTING

A single-center, university teaching hospital.

PARTICIPANTS

The study included 328 neonates and infants who underwent cardiac surgery on cardiopulmonary bypass.

INTERVENTIONS

A subset of 128 patients were studied: 58 patients undergoing ventricular septal defect (VSD) repair, 36 patients undergoing complete atrioventricular canal (CAVC) repair, and 34 patients undergoing bidirectional Glenn (BDG) shunt surgery.

MEASUREMENTS AND MAIN RESULTS

Of the entire cohort, 3.7% experienced in-hospital mortality. Among all surgical procedures, VSD repair (17.7%) was the most common, followed by CAVC repair (11.0%) and BDG shunt surgery (10.4%). Of patients who underwent VSD repair, CAVC repair, and BDG shunt surgery, 65.5%, 41.7%, and 67.6% were off mechanical ventilatory support within 24 hours postoperatively, respectively. In all three of the surgical repairs, lung compliance decreased after CPB compared to pre-CPB phase. Sixty point three percent of patients with VSD repair and 77.8% of patients with CAVC repair showed a PaO₂/F_IO₂ (P/F) ratio of <300 after CPB. Post- CPB P/F ratios of 120 for VSD patients and 100 for CAVC patients were considered as optimal cutoff values to highly predict prolonged (>24 hours) postoperative mechanical ventilatory support. A higher volume of transfused platelets also was associated with postoperative ventilatory support ≥24 hours in patients undergoing VSD repair, CAVC repair, and BDG shunt surgery.

CONCLUSIONS

There was a high incidence of lung injury after CPB in neonates and infants, even in surgeries amendable for early recovery. Given that CPB-related factors (CPB duration, crossclamp time) and volume of transfused platelet were significantly associated with prolonged postoperative ventilatory support, the underlying cause of cardiac surgery-related lung injury can be multi-factorial.

Anesthetics isoflurane and sevoflurane attenuate flagellin-mediated inflammation in the lung

Isoflurane and sevoflurane are volatile anesthetics (VA) widely used in clinical practice to provide general anesthesia. We and others have previously shown that VAs have immunomodulatory effects and may have a significant impact on the progression of disease states. Flagellin is a component of Gram negative bacteria and plays a significant role in the pathophysiology of bacterial pneumonia through its binding to Toll-like Receptor 5 (TLR5). Our results showed that VAs, not an intravenous anesthetic, significantly attenuated the activation of TLR5 and the release of the neutrophil chemoattractant IL-8 from lung epithelial cells. Furthermore, flagellin-induced lung injury was significantly attenuated by VAs by inhibiting neutrophil migration to the bronchoalveolar space. The lungs of cystic fibrosis (CF) patients are highly colonized by Pseudomonas aeruginosa, which causes inflammation. The retrospective study of oxygenation in patients with CF who had received VA versus intravenous anesthesia suggested that VAs might have the protective effect for gas exchange. To understand the interaction between VAs and TLR5, a docking simulation was performed, which indicated that isoflurane and sevoflurane docked into the binding interphase between TLR5 and flagellin.

Risk factors for pediatric surgical site infection following neurosurgical procedures for hydrocephalus: a retrospective single-center cohort study

Background

Infection is a major complication following cerebral spinal fluid (CSF) diversion procedures for hydrocephalus. However, pediatric risk factors for surgical site infection (SSI) are currently not well defined. Because a SSI prevention bundle is increasingly introduced, the purpose of this study was to evaluate risk factors associated with SSIs following CSF diversion surgeries following a SSI bundle at a single quaternary care pediatric hospital.

Methods

We performed a retrospective cohort study of patients undergoing CSF diversion procedures from 2017 to 2019. SSIs were identified prospectively through continuous surveillance. We performed unadjusted logistic regression analyses and univariate analyses to determine an association between SSIs and patient demographics, comorbidities and perioperative factors to identify independent risk factors for SSI.

Results

We identified a total of 558 CSF diversion procedures with an overall SSI rate of 3.4%. The SSI rates for shunt, external ventricular drain (EVD) placement, and endoscopic third ventriculostomy (ETV) were 4.3, 6.9 and 0%, respectively. Among 323 shunt operations, receipt of clindamycin as perioperative prophylaxis and presence of cardiac disease were significantly associated with SSI (O.R. 4.99, 95% C.I. 1.27–19.70, p = 0.02 for the former, and O.R. 7.19, 95% C.I. 1.35–38.35, p = 0.02 for the latter). No risk factors for SSI were identified among 72 EVD procedures.

Conclusion

We identified receipt of clindamycin as perioperative prophylaxis and the presence of cardiac disease as risk factors for SSI in shunt procedures. Cefazolin is recommended as a standard antibiotic for perioperative prophylaxis. Knowing that unsubstantiated beta-lactam allergy label is a significant medical problem, efforts should be made to clarify beta-lactam allergy status to maximize the number of patients who can receive cefazolin for prophylaxis before shunt placement. Further research is needed to elucidate the mechanism by which cardiac disease may increase SSI risk after shunt procedures.

Anesthetics may modulate cancer surgical outcome: a possible role of miRNAs regulation

Background

microRNAs (miRNAs) are single-stranded and noncoding RNA molecules that control post-transcriptional gene regulation. miRNAs can be tumor suppressors or oncogenes through various mechanism including cancer cell biology, cell-to-cell communication, and anti-cancer immunity.

Main Body

Anesthetics can affect cell biology through miRNA-mediated regulation of messenger RNA (mRNA). Indeed, sevoflurane was reported to upregulate miR-203 and suppresses breast cancer cell proliferation. Propofol reduces matrix metalloproteinase expression through its impact on miRNAs, leading to anti-cancer microenvironmental changes. Propofol also modifies miRNA expression profile in circulating extracellular vesicles with their subsequent anti-cancer effects via modulating cell-to-cell communication.

Conclusion

Inhalational and intravenous anesthetics can alter cancer cell biology through various cellular signaling pathways induced by miRNAs’ modification. However, this area of research is insufficient and further study is needed to figure out optimal anesthesia regimens for cancer patients.

Surgical Site Infections and Perioperative Optimization of Host Immunity by Selection of Anesthetics

Surgical site infections are significant health care issues, and efforts to mitigate their occurrence have been ongoing worldwide, mainly focusing to reduce the spillage of microbes to the otherwise sterile tissues. Optimization of host immunity has been also recognized including temperature regulation (normothermia), adequate oxygenation, and glucose management. A number of papers have described the role of anesthetics in host immunity. The role of anesthetics in postoperative outcomes including surgical site infections has been also studied. We will review the current literature and propose the importance of anesthetic selection to potentially mitigate surgical site infections.

Mechanistic consideration of the effect of perioperative volatile anesthetics on phagocytes

A growing literature has shown that volatile anesthetics are promiscuous molecules targeting multiple molecules, some of which are critical for immunological functions. We focused on studies that delineated target molecules of volatile anesthetics on immune cells and summarized the effects of volatile anesthetics on immune functions. We also presented the perspectives of studying volatile anesthetics-mediated immunomodulation.

Influence of anaesthetics on the production of cancer cell motogens, stromal cell-derived factor-1 and hepatocyte growth factor by fibroblasts

Anaesthetics have been implicated to influence cancer cells and progression. Similarly, crosstalk between cancer cells and stromal components within the microenvironment is also an important factor driving progression. Stromal cell-derived factor-1 (SDF-1) and hepatocyte growth factor (HGF) are key chemokines/cytokines produced by fibroblasts which have been established as influential factors in cancer progression. The present study explored the capacity of anaesthetics to influence the expression of these key molecules in fibroblasts. The anaesthetics rocuronium bromide (RB), vecuronium bromide (VB), suxamethonium chloride CRS (SCC), dexmedetomidine hydrochloride (DH) and lidocaine were used to treat MRC-5 fibroblasts over a range of concentrations. Following treatment, transcript expression of SDF-1 and HGF was quantified using quantitative PCR. Treatment of MRC-5 cells with RB brought about a reduction of SDF-1 expression which was found to be significant in the 45 µg/ml treatment group. Treatment with the other anaesthetics brought about some alterations in SDF-1 expression but these were not found to be statistically significant. Treatment with the tested anaesthetics did not have any significant effect on HGF transcript expression within MRC-5 cells, although again some alterations were observed. The results indicated that anaesthetics may have an impact on the fibroblast component of the tumour microenvironment, potentially influencing SDF-1 and HGF expression which in turn could influence tumour progression.

The Role of Anesthetic Management in Surgical Site Infections After Pediatric Intestinal Surgery

BACKGROUND

Although surgical site infections (SSIs) remain a significant health care issue, a limited number of studies have analyzed risk factors for SSIs in children, particularly the role of intraoperative anesthetic management. Pediatric patients are less likely to have major adult risk factors for SSIs such as smoking and diabetes. Thus children may be more suitable as a cohort for examining the role of intraoperative anesthetics in SSIs.

AIM

We examined an association between SSI incidence and anesthetic management in children who underwent elective intestinal surgery in a single institution.

METHODS

We performed a retrospective study of 621 patients who underwent elective intestinal surgery under general anesthesia between January 2017 and September 2019, with primary outcome as the incidence of SSIs. We compared patients who were dichotomized in accordance with the median of the sevoflurane dose. We used propensity score (PS) pairwise matching of these patients to avoid selection biases. PS matching yielded 204 pairs of patients.

RESULTS

We found that higher doses of sevoflurane were associated with a higher incidence of SSIs (9.8% versus 3.9%, P = 0.019). We adjusted for intraoperative factors that were not included in the PS adjustment factors, and multivariate regression analysis after PS matching showed compatible results (odds ratio: 2.58, 95% confidence interval: 1.11-6.04, P = 0.028).

CONCLUSIONS

Higher doses of sevoflurane are associated with increased odds of SSIs after pediatric elective intestinal surgery. A randomized controlled study of volatile anesthetic-based versus intravenous anesthetic-based anesthesia will be needed to further determine the role of anesthetic drugs in SSI risk.

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.

Role of Sevoflurane on Natural Killer Group 2, Member D-Mediated Immune Response in Non-Small-Cell Lung Cancer: An In Vitro Study

Background

The purpose of this study was to investigate the effects of sevoflurane on cancer immunosurveillance and metastasis in non-small-cell lung cancer (NSCLC).

Material/Methods

NCI-H23 cells, a human NSCLC cell line, were incubated with or without sevoflurane at the concentrations of 0, 12.5, 25, 50, 100, and 200 μM for 6 h. Cell viability, the expression of natural killer group 2, member D ligands (NKG2D ligands: UL16-binding proteins 1–3 [ULBP1–3] and major histocompatibility complex class I chain-related molecules A/B [MICA/B]), the expression of matrix metalloproteinases (MMPs), NK cell-mediated cytotoxicity, and cancer cell migration were measured.

Results

At 12.5, 25, 50, and 100 μM, sevoflurane increased the expression of NKG2D ligands (ULBP2–3 and MICA, ULBP1–3, ULBP1–3, and ULBP1, respectively). Sevoflurane decreased the expression of NKG2D ligands at 200 μM (MICA/B). NK cell-mediated lysis of NCI-H23 cells at 200 μM sevoflurane was significantly reduced compared with the control (P=0.025; target cell: effect cell=1: 10). Sevoflurane increased the expression of MMP-1, -2, and -9 and increased cell migration in NCI-H23 cells at 50, 100, and 200 μM (P=0.001, 0.035, and 0.039, respectively, compared with the control after 18 h of wound formation).

Conclusions

Sevoflurane could suppress NKG2D-mediated NK cell cytotoxicity and increased expression of MMPs and migration in NCI-H23 cells. Further research is needed to determine the effects of sevoflurane on cancer immunosurveillance and metastasis in NSCLC.

The effect of anesthetics on toll like receptor 9

Toll like receptors (TLRs) are critical receptors to respond to danger signals, and their functions are relevant in the perioperative period. We previously reported that volatile anesthetics directly bound to TLR2 and TLR4 and attenuated their functions. Given that TLR9 can respond to mitochondrial DNA, a danger signal that is released upon tissue injury, we examined the role of anesthetics on TLR9 function. Our reporter assay showed that volatile anesthetics isoflurane and sevoflurane increased the activation of TLR9, while propofol attenuated it. TLR9 activation occurs via its dimerization. The dimerization is facilitated by unmethylated cytosine-phosphate-guanine (CpG) DNA as well as DNA containing cytosine at the second position from 5'-end (5'-xCx DNA). Our structural analysis using photoactivable anesthetics and rigid docking simulation showed that isoflurane and sevoflurane bound to both TLR9 dimer interface and 5'-xCx DNA binding site. Propofol bound to the TLR9 antagonist binding site. This is the first illustration that anesthetics can affect the binding of nucleic acids to their receptor. This study sets the foundation for the effect of anesthetics on TLR9 and will pave the way for future studies to determine the significance of such interactions in the clinical setting.

Volatile Anesthetic Sevoflurane Attenuates Toll-Like Receptor 1/2 Activation

BACKGROUND

Although immunomodulatory effects of anesthetics have been increasingly recognized, their underlying molecular mechanisms are not completely understood. Toll-like receptors (TLRs) are one of the major receptors to recognize invading pathogens and danger signals from damaged host tissues to initiate immune responses. Among the TLR family, TLR2 and TLR4 recognize a wide range of ligands and are considered to be important players in perioperative pathophysiology. Based on our recent finding that volatile anesthetics modulate TLR4 function, we tested our hypothesis that they would also modulate TLR2 function.

METHODS

The effect of anesthetics isoflurane, sevoflurane, propofol, and dexmedetomidine on TLR2 activation was examined by reporter assays. An anesthetic that affected the activation was subjected to in silico rigid docking simulation on TLR2. To test our prediction that sevoflurane and a TLR1/TLR2 ligand Pam3CSK4 would compete for the same pocket of TLR2, we performed Pam3CSK4 competitive binding assay to TLR2 using HEK cells stably transfected with TLR2 (HEK-TLR2) with or without sevoflurane. We examined the effect of different anesthetics on the functions of human neutrophils stimulated with TLR2 ligands. Kruskal-Wallis test and Mann-Whitney U test were used for statistical analysis.

RESULTS

We observed that the attenuation of TLR1/TLR2 activation was seen on sevoflurane exposure but not on isoflurane, propofol, or dexmedetomidine exposure. The attenuation of TLR2/TLR6 activation was not seen in any of the anesthetics tested. The rigid docking simulation predicted that sevoflurane and Pam3CSK4 bound to the same pocket of TLR1/TLR2 complex. The binding of Pam3CSK4 to HEK-TLR2 cells was impaired in the presence of sevoflurane, indicating that sevoflurane and Pam3CSK4 competed for the pocket, as predicted in silico. The stimulation of neutrophils with Pam3CSK4 induced L-selection shedding but did not affect phagocytosis and reactive oxygen species production. L-selectin shedding from neutrophils was attenuated only by sevoflurane, consistent with the result of our reporter assays.

CONCLUSIONS

We found that TLR1/TLR2 activation was attenuated by sevoflurane, but we found no evidence for attenuation by isoflurane, propofol, or dexmedetomidine at clinically relevant concentrations. Our structural analysis and competition assay supported that sevoflurane directly bound to TLR2 at the interphase of the TLR1/TLR2 complex. Sevoflurane attenuated neutrophil L-selectin shedding, an important step for neutrophil migration.

Effects of propofol and dexmedetomidine with and without remifentanil on serum cytokine concentrations in healthy volunteers: a post hoc analysis

BACKGROUND

Anaesthetic agents are likely to alter circulating cytokine concentrations. Because preceding studies have not been able to exclude the contribution of surgical trauma, perioperative stress, or both to circulating cytokine concentrations, the effects of anaesthesia remain unclear. The aim of this study was to quantify serum cytokines in healthy volunteers administered i.v. anaesthetic agents in the absence of surgical trauma and perioperative stress.

METHODS

Serum samples obtained during previous standardised studies from healthy volunteers were compared before and 6-8 h after induction of anaesthesia with propofol (n=31), propofol/remifentanil (n=30), dexmedetomidine (n=17) or dexmedetomidine/remifentanil (n=15). Anaesthetic regimens were standardised and volunteers did not undergo any surgical intervention. Serum concentrations of interleukin (IL)2, IL4, IL6, IL10, IL17, IL18, IL21, IL22, IL23, C-X-C motif ligand 8, interferon gamma, E-selectin, L-selectin, major histocompatibility complex class I chain-polypeptide-related sequence (MIC)A, MICB, Granzyme A, and Granzyme B were quantified using a multiplexed antibody-based assay (Luminex).

RESULTS

Samples were obtained from volunteers of either sex aged 18-70 yr. After anaesthesia with propofol alone, concentrations of IL4 (P=0.012), IL6 (P=0.027), IL21 (P=0.035), IL22 (P=0.002), C-X-C motif ligand 8 (P=0.004), MICB (P=0.046), and Granzyme A (P=0.045) increased. After anaesthesia with propofol and remifentanil, IL17 (P=0.013), interferon gamma (P=0.003), and MICA (P=0.001) decreased, but IL6 (P=0.006) and L-selectin (P=0.001) increased. After dexmedetomidine alone, IL18 (P=0.002), L-selectin (P=0.017), E-selectin (P=0.002), and Granzyme B (P=0.023) decreased. After dexmedetomidine with remifentanil no changes were observed.

CONCLUSIONS

In healthy volunteers not undergoing surgery, different i.v. anaesthesia regimens were associated with differential effects on circulating cytokines.

Anesthesia Options and the Recurrence of Cancer: What We Know so Far?

Surgery is a critical period in the survival of patients with cancer. While resective surgery of primary tumors has shown to prolong the life of these patients, it can also promote mechanisms associated with metastatic progression. During surgery, patients require general and sometimes local anesthetics that also modulate mechanisms that can favor or reduce metastasis. In this narrative review, we summarized the evidence about the impact of local, regional and general anesthesia on metastatic mechanisms and the survival of patients. The available evidence suggests that cancer recurrence is not significantly impacted by neither regional anesthesia nor volatile or total intravenous anesthesia.

The Role of Inhaled Anesthetics in Tumorigenesis and Tumor Immunity

Inhaled anesthetics are widely used for induction and maintenance of anesthesia during surgery, including isoflurane, sevoflurane, desflurane, haloflurane, nitrous oxide (N₂O), enflurane and xenon. Nowadays, it is controversial whether inhaled anesthetics may influence the tumor progression, which urges us to describe the roles of different inhaled anesthetics in human cancers. In the review, the relationships among the diverse inhaled anesthetics and patient outcomes, immune response and cancer cell biology were discussed. Moreover, the mechanisms of various inhaled anesthetics in the promotion or inhibition of carcinogenesis were also reviewed. In summary, we concluded that several inhaled anesthetics have different immune functions, clinical outcomes and cancer cell biology, which could contribute to opening new avenues for selecting suitable inhaled anesthetics in cancer surgery.

In Vitro Model of Stretch-Induced Lung Injury to Study Different Lung Ventilation Regimens and the Role of Sedatives

BACKGROUND

Currently lung injury is managed conservatively through supportive care including mechanical ventilation. However, mechanical ventilation can also cause additional lung injury due to over-stretch along with atelectasis and cytokine release. Here we developed an in vitro mechanical ventilation model using cyclic stretch of lung epithelial cells to mimic high and low tidal volume (TV) ventilation strategy, so that we could use this platform for pathophysiology analysis and screening for therapeutic drugs.

METHOD

We subjected MLE-15 cells to the following treatments. 1) No treatment, 2) lipopolysaccharide (100 ng/mL) stimulation for 24 hours, 3) mechanical stretch initiated at 6-hour time point for 18 hours, 4) LPS stimulation at time point 0 hour, and mechanical stretch was added at 6-hour time point for 18 hours. Biaxial cyclic stretch with a triangular wave was given via the Flexcell FX-6000 tension system to mimic low and high TV. Anesthetics dexmedetomidine and propofol were also tested.

RESULT

Our high TV mimic stretch increased cell death, while low TV mimic stretch did not affect the degree of cell death. Using this system, we examined the effect of sedatives commonly used in intensive care units on cell death and found that dexmedetomidine attenuated necrosis associated with stretch.

CONCLUSION

We described the in vitro cyclic stretch system mimicking high and low TV ventilation. High TV mimetic was associated with increased cell death. Dexmedetomidine attenuated the degree of cell death.

Propofol affects the growth and metastasis of pancreatic cancer via ADAM8

BACKGROUND

Anesthesia is a major component of surgery and recently considered an important regulator of cell phenotypes. Here we aimed to investigate propofol, an anesthesia drug, in suppressing pancreatic cancer (PDAC), focusing on A disintegrin and metalloprotease 8, (ADAM8) as a molecular mediator.

METHODS

Quantitative real-time PCR and western blot were used to assess the change of ADAM8 expression in Panc1 PDAC cells treated with 5 or 10 μg/mL propofol, using cells treated with BB-94 inhibitor as controls. ADAM8 activity was measured through quantifying fluorescence release induced by PEPDAB013 decomposition. MTT assay, scratch wound assay and Matrigel invasion assay were used to investigate the proliferation, migration and invasion of the cells. Western blot and immunohistochemical analysis were used to quantify integrin β1, ERK1/2, MMP2 and MMP9 expression.

RESULTS

Propofol and BB-94 reduced ADAM8 expression, cell proliferation and migration of Panc1 cells. Tumor growth was inhibited by propofol and BB-94, concomitant with downregulation of integrin β1, ERK1/2, MMP2 and MMP9. ADAM8 is downregulated by propofol, leading to inhibition of pancreatic cancer proliferation and migration.

CONCLUSION

Pancreatic tumor growth is also inhibited by propofol and BB-94, which is attributed to suppression of ERK/MMPs signaling.

Emerging effect of anesthesia on post-operative tumor recurrence and metastasis

Post-operative recurrence and metastasis of malignant tumors are difficult to control, which probably results from multiple factors that affect the prognosis and the undefined mechanism. Anesthesia may be an influential factor. Researchers have performed many meaningful studies on the relationship between anesthetic drugs/methods and tumor growth/immune function, which provide important references for the anesthetic selection and peri-operative management of tumor patients. Anesthetics, analgesics, and sedatives should be used with caution because their effects in post-operative patients remain controversial. This review summarizes the emerging progress on the effect of anesthesia on post-operative tumor recurrence and metastasis, particularly focusing on the effects of anesthetic drugs, anesthetic methods, and post-operative analgesia on tumor growth and metastasis. Future studies should provide strict criteria for the proper use of anesthetics in patients with malignant tumors and provide experimental evidence for the improvement and development of novel anesthetics and anesthetic methods that have the important clinical significance.