Immune Modulation by Volatile Anesthetics. Anesthesiology. 2016;125:399-411. [PMID: 27286478 DOI: 10.1097/aln.0000000000001195]

Early and Long-Term Outcomes after Propofol-and Sevoflurane-Based Anesthesia in Colorectal Cancer Surgery: A Retrospective Study

Background: Propofol is considered to protect against immunosuppression and has lower inflammatory responses in the perioperative period than volatile agents. We evaluated whether the anesthetic agent is associated with cancer outcomes. Methods: We retrospectively reviewed 2616 patients who underwent colorectal cancer surgery under general anesthesia between 2016 and 2018 (follow-up closure: July 2021) at a single institution. Patients received propofol-based total intravenous anesthesia or sevoflurane-based inhalational anesthesia. After propensity score matching, the postoperative neutrophil-lymphocyte ratio (NLR) was compared as primary outcome, and clinical outcomes were evaluated. Results: After 1:2 propensity matching, 717 patients were given propofol anesthesia and 1410 patients were given sevoflurane anesthesia. In the matched cohort, preoperative NLR was not significantly different between propofol and sevoflurane anesthesia (mean (95% CI)2.3 (1.8 to 2.8) and 2.2 (1.9 to 3.2); p = 0.72). NLR was significantly lower in propofol anesthesia at postoperative day two and five (mean difference (95% CI) 0.71 (0.43 to 0.98); p = 0.000 and 0.52 (0.30 to 0.74); p = 0.000). Urinary retention showed a higher incidence after propofol anesthesia (4.9% vs. 2.6%; p = 0.008). Other postoperative complications and overall/recurrence-free survival were not different in the two groups. Discussion: Although propofol anesthesia showed lower postoperative NLR than sevoflurane anesthesia, there was no association with clinical outcomes.

Inhaled Sedation for Invasively Ventilated COVID-19 Patients: A Systematic Review

Background: Volatile anesthetics were used as sedative agents in COVID-19 (Coronavirus Disease 2019) invasively ventilated patients for their potentially beneficial pharmacological effects and due to the temporary shortages of intravenous agents during the pandemic crisis. Methods: Online databases (PubMed, EMBASE, The Cochrane Central Register of Controlled Trial) and the “clinicaltrials.gov” website were searched for studies reporting the use of isoflurane, sevoflurane or desflurane. Results: We identified three manuscripts describing the beneficial effects of isoflurane on 41 COVID-19 patients with acute respiratory distress syndrome (ARDS) in Germany (n = 2) and in the USA (n = 1), in terms of reduction in the use of opioids and other sedatives. We also found a case report of two patients with transient nephrogenic diabetes insipidus, which started after 6 and 8 days of sevoflurane sedation. We identified two randomized controlled trials (RCTs; 92 patients overall), two observational studies (238 patients) on the use of volatile anesthetics in COVID-19 patients that were completed but not yet published, and one RCT interrupted for a low recruitment ratio (19 patients) and thus not published. We also identified five ongoing RCTs on the use of inhaled sedation in ARDS, which are also likely to be recruiting COVID-19 patients and which have currently enrolled a total of >1643 patients. Conclusion: Isoflurane was the most frequently used volatile agent in COVID-19 patients and allowed a reduction in the use of other sedative and analgesic drugs. Randomized evidence is building up and will be useful to confirm or challenge these findings.

Inhalation anaesthesia compared with total intravenous anaesthesia and postoperative complications in colorectal cancer surgery: an observational registry-based study†

BACKGROUND

Postoperative complications are common after colorectal surgery, and possibly related to the type of anaesthesia. We aimed to determine associations between the type of anaesthesia and complications after colorectal cancer surgery using Danish registries.

METHODS

Patients undergoing colorectal cancer surgery (2004-18) were identified in the Danish Colorectal Cancer Group Database. The cohort was enriched with the Danish Anaesthesia Database and Danish National Prescription Registry data linked by Danish Central Person Registration number. Patients were classified according to type of general anaesthesia: inhalation or TIVA. Confounders were adjusted by propensity score matching. The primary outcome was complications within 30 days postoperatively. Secondarily, we assessed specific medical and surgical complications.

RESULTS

We identified 22 179 individuals undergoing colorectal cancer surgery with accompanying anaesthesia data. Propensity score matching yielded 8722 individuals per group. After propensity score matching, postoperative complications were seen in 1933 (22.2%) patients undergoing inhalation anaesthesia and in 2199 (25.2%) undergoing TIVA (odds ratio [OR]=0.84; 95% confidence interval [CI], 0.79-0.91). Although no difference was observed for medical complications, 1369 (15.7%) undergoing inhalation anaesthesia had surgical complications compared with 1708 (19.6%) undergoing TIVA (OR=0.76; 95% CI, 0.71-0.83). Rates of wound dehiscence, anastomotic leak, ileus, wound abscess, intra-abdominal abscess, and sepsis were statistically significantly lower in the inhalation anaesthesia group.

CONCLUSION

In this propensity score-matched registry study, use of inhalation anaesthesia was associated with fewer postoperative complications after colorectal cancer surgery than use of TIVA. Inhalation anaesthesia was associated with fewer complications related to wound healing and surgical infections.

Anesthesia and Oncology: Friend or Foe?

Cancer is a leading cause of death, and surgery is an important treatment modality. Laboratory research and retrospective studies have raised the suspicion that the choice of anesthetics for cancer surgery might affect the course of cancerous disease. The aim of this review is to provide a critical overview of the current state of knowledge. Inhalational anesthesia with volatiles or total intravenous anesthesia (TIVA) with propofol are the two most commonly used anesthetic techniques. Most data comparing volatile anesthetics with TIVA is from either in vitro or retrospective studies. Although conflicting, data shows a trend towards favoring propofol. Opioids are commonly used in anesthesia. Data on potential effects of opioids on growth and recurrence of cancer are scarce and conflicting. Preclinical studies have shown that opioids stimulate cancer growth through the µ-opioid receptor. Opioids also act as immunosuppressants and, therefore, have the potential to facilitate metastatic spread. However, the finding of an adverse effect of opioids on tumor growth and cancer recurrence by some retrospective studies has not been confirmed by prospective studies. Regional anesthesia has not been found to have a beneficial effect on the outcome of surgically treated cancer patients, but prospective studies are scarce. Local anesthetics might have a beneficial effect, as observed in animal and in vitro studies. However, prospective clinical studies strongly question such an effect. Blood products, which may be needed during extensive cancer surgery suppress the immune system, and data strongly suggest a negative impact on cancer recurrence. The potential effects of other commonly used anesthetic agents on the outcome of cancer patients have not been sufficiently studied for drawing valid conclusions. In conclusion, laboratory data and most retrospective studies suggest a potential advantage of TIVA over inhalational anesthesia on the outcome of surgical cancer patients, but prospective, randomized studies are missing. Given the state of weak scientific evidence, TIVA may be used as the preferred type of anesthesia unless there is an individual contraindication against it. Studies on the effects of other drugs frequently used in anesthesia are limited in number and quality, and have found conflicting results.

General anesthesia bullies the gut: a toxic relationship with dysbiosis and cognitive dysfunction

Perioperative neurocognitive disorder (PND) is a common surgery outcome affecting up to a third of the elderly patients, and it is associated with high morbidity and increased risk for Alzheimer's disease development. PND is characterized by cognitive impairment that can manifest acutely in the form of postoperative delirium (POD) or after hospital discharge as postoperative cognitive dysfunction (POCD). Although POD and POCD are clinically distinct, their development seems to be mediated by a systemic inflammatory reaction triggered by surgical trauma that leads to dysfunction of the blood-brain barrier and facilitates the occurrence of neuroinflammation. Recent studies have suggested that the gut microbiota composition may play a pivotal role in the PND development by modulating the risk of neuroinflammation establishment. In fact, modulation of gut microbiome composition with pre- and probiotics seems to be effective for the prevention and treatment of PND in animals. Interestingly, general anesthetics seem to have major responsibility on the gut microbiota composition changes following surgery and, consequently, can be an important element in the process of PND initiation. This concept represents an important milestone for the understanding of PND pathogenesis and may unveil new opportunities for the development of preventive or mitigatory strategies against the development of these conditions. The aim of this review is to discuss how anesthetics used in general anesthesia can interact and alter the gut microbiome composition and contribute to PND development by favoring the emergence of neuroinflammation.

Current Status and Prospects of Anesthesia and Breast Cancer: Does Anesthetic Technique Affect Recurrence and Survival Rates in Breast Cancer Surgery?

The relationship between the anesthetic technique and cancer recurrence has not yet been clarified in cancer surgery. Surgical stress and inhalation anesthesia suppress cell-mediated immunity (CMI), whereas intravenous (IV) anesthesia with propofol and regional anesthesia (RA) are known to be protective for CMI. Surgical stress, general anesthesia (GA) with inhalation anesthesia and opioids contribute to perioperative immunosuppression and may increase cancer recurrence and decrease survival. Surgical stress and GA activate the hypothalamic-pituitary-adrenal axis and release neuroendocrine mediators such as cortisol, catecholamines, and prostaglandin E₂, which may reduce host defense immunity and promote distant metastasis. On the other hand, IV anesthesia with propofol and RA with paravertebral block or epidural anesthesia can weaken surgical stress and GA-induced immunosuppression and protect the host defense immunity. IV anesthesia with propofol and RA or in combination with GA may reduce cancer recurrence and improve patient survival compared to GA alone. We review the current status of the relationship between anesthesia and breast cancer recurrence using retrospective and prospective studies conducted with animal models and clinical samples, and discuss the future prospects for reducing breast cancer recurrence and improving survival rates in breast cancer surgery.

Antitumor Anesthetic Strategy in the Perioperatory Period of the Oncological Patient: A Review

The stress response triggered by the surgical aggression and the transient immunosuppression produced by anesthetic agents stimulate the inadvertent dispersion of neoplastic cells and, paradoxically, tumor progression during the perioperative period. Anesthetic agents and techniques, in relation to metastatic development, are investigated for their impact on long-term survival. Scientific evidence indicates that inhaled anesthetics and opioids benefit immunosuppression, cell proliferation, and angiogenesis, providing the ideal microenvironment for tumor progression. The likely benefit of reducing their use, or even replacing them as much as possible with anesthetic techniques that protect patients from the metastatic process, is still being investigated. The possibility of using "immunoprotective" or "antitumor" anesthetic techniques would represent a turning point in clinical practice. Through understanding of pharmacological mechanisms of anesthetics and their effects on tumor cells, new perioperative approaches emerge with the aim of halting and controlling metastatic development. Epidural anesthesia and propofol have been shown to maintain immune activity and reduce catecholaminergic and inflammatory responses, considering the protective techniques against tumor spread. The current data generate hypotheses about the influence of anesthesia on metastatic development, although prospective trials that determinate causality are necessary to make changes in clinical practice.

Radiotherapy as a tool to elicit clinically actionable signalling pathways in cancer

A variety of targeted anticancer agents have been successfully introduced into clinical practice, largely reflecting their ability to inhibit specific molecular alterations that are required for disease progression. However, not all malignant cells rely on such alterations to survive, proliferate, disseminate and/or evade anticancer immunity, implying that many tumours are intrinsically resistant to targeted therapies. Radiotherapy is well known for its ability to activate cytotoxic signalling pathways that ultimately promote the death of cancer cells, as well as numerous cytoprotective mechanisms that are elicited by cellular damage. Importantly, many cytoprotective mechanisms elicited by radiotherapy can be abrogated by targeted anticancer agents, suggesting that radiotherapy could be harnessed to enhance the clinical efficacy of these drugs. In this Review, we discuss preclinical and clinical data that introduce radiotherapy as a tool to elicit or amplify clinically actionable signalling pathways in patients with cancer.

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.

An atlas of dynamic peripheral blood mononuclear cell landscapes in human perioperative anaesthesia/surgery

BACKGROUND

The number of patients receiving anaesthesia is increasing, but the impact of general anaesthesia on the patient's immune system remains unclear. The aim of the present study is to investigate dynamics of systemic immune cell responses to anaesthesia during perioperative period at a single-cell solution.

METHODS

The peripheral blood mononuclear cells (PBMCs) and clinical phenomes were harvested and recorded 1 day before anaesthesia and operation, just after anaesthesia (0 h), and 24 and 48 h after anaesthesia. Single-cell sequencing of PBMCs was performed with 10× genomics. Subsequently, data analysis was performed with R packages: Seurat, clusterProfiler and CellPhoneDB.

RESULTS

We found that the cluster of CD56+ NK cells changed at 0 h and the cluster of monocytes increased at 24 and 48 h after anaesthesia. The characteristic genes of CD56+ NK cells were mainly enriched in the Jak-STAT signalling pathway and in cell adhesion molecules (24 h) and carbon metabolism (48 h). The communication between CD14+ monocytes and other cells decreased substantially 0 and 48 h after operation. The number of plasma cells enriched in protein export in men was substantially higher than that in women, although the total number in patients decreased 24 h after operation. CD14+ monocytes dominated that cell-cell communications appeared in females, while CD8+ NKT cells dominated that cell-cell communications appeared in male. The number of plasma cells increased substantially in patients with major surgical trauma, with enrichments of pentose phosphate pathway. The communications between plasma cells with other cells varied between surgical severities and anaesthetic forms. The intravenous anaesthesia caused major alterations of cell types, including CD14+ monocytes, plasmas cells and MAIT cells, as compared with inhalation anaesthesia.

CONCLUSION

We initially reported the roles of perioperative anaesthesia/surgery in temporal phenomes of circulating immune cells at a single-cell solution. Thus, the protection against immune cell changes would benefit the recovery from anaesthesia/surgery.

Peri-operative approach to esophagectomy: a narrative review from the anesthesiological standpoint

Objective

This review summarizes the peri-operative anesthesiological approaches to esophagectomy considering the best up-to-date, evidence-based medicine, discussed from the anesthesiologist’s standpoint.

Background

Esophagectomy is the only curative therapy for esophageal cancer. Despite the many advancements made in the surgical treatment of this tumour, esophagectomy still carries a morbidity rate reaching 60%. Patients undergoing esophagectomy should be referred to high volume centres where they can receive a multidisciplinary approach to treatment, associated with better outcomes. The anesthesiologist is the key figure who should guide the peri-operative phase, from diagnosis through to post-surgery rehabilitation. We performed an updated narrative review devoted to the study of anesthesia management for esophagectomy in cancer patients.

Methods

We searched MEDLINE, Scopus and Google Scholar databases from inception to May 2021. We used the following terms: “esophagectomy”, “esophagectomy AND pre-operative evaluation”, “esophagectomy AND protective lung ventilation”, “esophagectomy AND hemodynamic monitoring” and “esophagectomy AND analgesia”. We considered only articles with abstract written in English and available to the reader. We excluded single case-reports.

Conclusions

Pre-operative anesthesiological evaluation is mandatory in order to stratify and optimize any medical condition. During surgery, protective ventilation and judicious fluid management are the cornerstones of intraoperative “protective anesthesia”. Post-operative care should be provided by an intensive care unit or high-dependency unit depending on the patient’s condition, the type of surgery endured and the availability of local resources. The provision of adequate post-operative analgesia favours early mobilization and rapid recovery. Anesthesiologist has an important role during the peri-operative care for esophagectomy. However, there are still some topics that need to be further studied to improve the outcome of these patients.

Anesthetics mediated the immunomodulatory effects via regulation of TLR signaling

Anesthetics have been widely used in surgery and found to suppress inflammatory injury and affect the outcomes of the surgery and diseases. In contrast, anesthetics are also found to induce neuronal injury and inflammation. However, the immune-modulation mechanism of anesthetics is still not clear. Recent studies have shown that the immune-modulation of anesthetics is associated with the regulation of toll-like receptor (TLR)-mediated signaling. Moreover, the regulation of anesthetics in TLR signaling is related to modulations of non-coding RNAs (nc RNAs). Consistently, nc RNAs are mainly divided into micro RNAs (miRs) and long non-coding RNAs (lnc RNAs), which have been found to exert regulatory effects on the immune system. In this review, we summarize the immunomodulatory functions of the widely used anesthetic agents, which are associated with regulation of TLR signaling. In addition, we also focus on the roles of nc RNAs induced by anesthetics in regulations of TLR signaling.

Effect of inhaled anaesthetics gases on cytokines and oxidative stress alterations for the staff health status in hospitals

OBJECTIVES

The present study aimed to evaluate the effects of waste anaesthetic gases on cytokines and oxidative stress of hospital health team members following exposure to waste anaesthetic gases (WAGs).

SUBJECTS AND METHODS

In total, 180 participants took part in this study; 60 of these were healthy male controls and the 120 participants in the intervention group were staff who work in the operating room. This latter group comprises six occupational subgroups (1) surgeons, (2) surgical assistants, (3) anaesthesiologists (4) anaesthesiology assistants, (5) nurses and (6) janitors. The following parameters were assessed: catalase (CAT), glutathione peroxidase (GSHpx) and superoxide dismutase (SOD) activities, plasma fluoride, serum interferon gamma (IFN-γ), serum interleukin 2 (IL2), serum interleukin 4 (IL4) and plasma thiobarbituric acid reactive substances (TBARS).

RESULTS

Anaesthesiologists and their assistants exhibited the highest levels of plasma fluoride, serum IFN-γ and IL 2, exceeding the levels in detected in all the other occupational subgroups. Furthermore, the serum levels of IL4 were significantly raised in anaesthesiologists and the difference between this group and other groups was statistically significant. However, compared with the other subgroups, surgeons exhibited elevated plasma TBARS and reduced CAT, GSHpx and SOD; these variances were also statistically significant.

CONCLUSION AND RECOMMENDATIONS

The findings of this study indicate that operating room staff exposed to WAGs are vulnerable to experiencing immunotoxicity as the WAGs are considered to initiate oxidative stress and increase the levels of cytokines in serum. Thus, an education programme is warranted to inform staff working in environments where they may be subjected to WAGs on the effects that the gases can have upon their health and how to minimise their exposure to WAGs. An ongoing effort is also needed to ensure anaesthesia safety standards are maintained at all times. The findings of this study may provide a springboard for future research into occupational exposure to WAGs and their wider effect upon health.

Effects of Serum From Radiofrequency Ablation Patients Receiving General Anesthesia or Local Anesthesia on Hepatocellular Carcinoma Cancer Cell Malignancy: A Prospective Randomized Controlled Trial

Background

Whether anesthesia methods affect malignant biological behavior of cancer remains unresolved. In this study, we aim to compare the effects of general anesthesia (GA) and local anesthesia (LA) on serum collected from primary hepatocellular carcinoma (HCC) patients presenting for radiofrequency ablation (RFA).

Methods

From August 2020 to December 2020, a prospective, randomized, and controlled study was conducted at Renji Hospital, which is affiliated with Shanghai Jiaotong University School of Medicine. 25 qualified patients from 18 to 65 years of age undergoing RFA were enrolled in the study and randomly assigned into two groups: the GA group (n = 14) and the LA group (n = 11). Venous blood was drawn from all patients preoperatively and 1 hour postoperatively. The serum collected was then used for the culturing of HepG2 cells. The malignant biological behaviors of HepG2 cells, including invasion, migration and proliferation, were observed after 24 hours of exposure to patients’ serum. ELISA was used to compare expression levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) and lymphokines (IFN-γ, IL-2) in patients’ serum from both groups.

Results

HepG2 cells cultured with postoperative serum obtained from patients who received GA, but not LA, were associated with significantly increased cell invasion, migration and proliferation, compared to preoperative serum from the same patient group. Expression levels of pro-inflammatory cytokines were significantly higher, and lymphokines significantly lower in postoperative serum from GA patients compared to the corresponding preoperative serum.

Conclusion

GA affects the serum milieu of patients with HCC, promoting the malignant biological behavior of a human HCC cell line.

A 20-Year Research Trend Analysis of the Influence of Anesthesia on Tumor Prognosis Using Bibliometric Methods

Background

Bibliometric analysis is used to gain a systematic understanding of developments in the field of the influence of anesthesia on tumor prognosis and changes in research hot spots over the past 20 years.

Methods

Relevant publications from the Web of Science Core Collection (WoSCC) were downloaded on May 5, 2021. Acquired data were then analyzed using the Online Analysis Platform of Literature Metrology (http://biblimetric.com) and the CiteSpace software was used to analyze and predict trends and hot spots in this field.

Results

1,521 publications on the influence of anesthesia on tumor prognosis were identified and 1494 qualifying records were included in the final analysis. The leading country in this field was the United States of America (USA). The University of Texas MD Anderson Cancer Center (Houston, TX, USA) and Pennsylvania State University (State College, PA, USA) featured the highest number of publications among all institutions. Co-citation cluster labels revealed characteristics of ten main clusters: total intravenous anesthesia, opioid growth factor receptor, gastric cancer cell, opioid receptor, murine model, natural killer cell activity, health-related quality, glioma cell, opioid switching and mu-type opioid receptor. Keyword burst detection indicated that randomized controlled trials (RCTs), volatile anesthetics, and ropivacaine were the newly emerging research hot spots.

Conclusions

This study compiled 1494 publications covering anesthesia and tumor prognosis research and showed that the direction of these studies is likely in transition from opioids and their receptors to other anesthetics, and from retrospective studies to prospective randomized controlled trials. It provides guidance for further research and clinical applications on choosing anesthetic methods and drugs.

TIVA versus Inhalational Agents for Pediatric Cardiac Intensive Care

The field of pediatric intensive care has come a long way, especially with the recognition that adequate sedation and analgesia form an imperative cornerstone of patient management. With various drugs available for the same, the debate continues as to which is the better: total intravenous anesthesia (TIVA) or inhalational agents. While each have their own advantages and disadvantages, in the present era of balance toward the IV agents, we should not forget the edge our volatile agents (VAs) might have in special scenarios. And ultimately as anesthesiologists, let us not forget that be it knob and dial, or syringe and plunger, our aim is to put pain to sleep and awaken a new faith to breathe.

Association Between Anesthesia Delivered During Tumor Resection and Cancer Survival: a Systematic Review of a Mixed Picture with Constant Themes

BACKGROUND

Surgery is required for cure of most solid tumors, and general anesthesia is required for most cancer surgery. The vast majority of cancer surgery is facilitated by general anesthesia using volatile inhalational agents such as isoflurane and sevoflurane. Only recently have the immunologic and oncologic effect of inhalational agents, and their alternative, propofol-based total intravenous anesthesia (TIVA), come under investigation.

METHODS

Between January 2019 and June 2020, English language articles on PubMed were searched for the keywords "Propofol" "TIVA" or "IV anesthesia" and either "cancer surgery" or "surgical oncology." Duplicates were removes, manuscripts classified as either in vitro, animal, translational, or clinical studies, and their results summarized within these categories.

RESULTS

In-vitro and translational data suggest that inhalational anesthetics are potent immunosuppressive and tumorigenic agents that promote metastasis, while propofol is anti-inflammatory, anti-tumorigenic, and prevents metastasis development. Clinically there is a recurring association, based largely on retrospective, single institution series, that TIVA is associated with significant improvements in disease-free interval and overall survival in a number of, but not all, solid tumors. The longer the surgery is, the more intense the surgical trauma is, the more aggressive the malignancy is, and the higher likelihood of an association is.

DISCUSSION

Prospective randomized trials, coupled with basic science and translational studies, are needed to further define this association.

Comparison of Outcomes After Breast Cancer Surgery Between Inhalational and Propofol-Based Intravenous Anaesthesia: A Systematic Review and Meta-Analysis

Background

General anaesthesia is the commonly provided for breast cancer surgery, but the effects of inhalational anaesthesia and propofol-based intravenous anaesthesia on short- and long-term outcomes after breast cancer surgery are not clear. In this study, we conduct a meta-analysis of randomized controlled trials (RCTs) to explore the superior anaesthetic for breast cancer surgery patients.

Methods

We searched the Embase, Medline, Cochrane Library, Web of Science, CNKI, and Wanfang databases (up to January, 2021) for RCTs in which inhalational anaesthesia and propofol-based intravenous anaesthesia were compared and short- and long-term outcomes were assessed in breast cancer surgical patients. The meta-analysis was performed by Stata 12.0.

Results

Twenty RCTs with a total of 2201 patients were included. Compared with inhalational anaesthesia, propofol-based intravenous anaesthesia was associated with more postoperative rescue analgesia (I²=0%, RR: 1.18, 95% CI: 1.07–1.30, P=0.001) but a lower incidence of postoperative nausea and vomiting (PONV) (I²=25.5%, RR: 0.71, 95% CI: 0.62–0.81, P<0.001) and postoperative rescue antiemetics (I²=0%, RR: 0.69, 95% CI: 0.58–0.82, P<0.001). Propofol-based intravenous anaesthesia preserved nature killer cell cytotoxicity (I²=86.2%, SMD: 0.76, 95% CI: 0.13–1.39, P=0.018), decreased IL-6 level (I²=98.0%, SMD: −3.09, 95% CI: −5.70– −0.48, P=0.021) and neutrophil-to-lymphocyte ratio (I²=0%, SMD: −0.28, 95% CI: −0.53– −0.03, P=0.030), and increased 2-year recurrence-free survival rate (I²=0%, RR: 1.10, 95% CI: 1.00–1.20, P=0.043) but did not affect recurrence or the overall survival rate (P>0.05).

Conclusion

Propofol-based intravenous anaesthesia increases postoperative rescue analgesia but reduces PONV compared with inhalational anaesthesia in breast cancer surgery. The benefit of propofol over inhalational anaesthetics in the preservation of anti-cancer immunity is obvious, but it is difficult to conclude that propofol can exert long-term benefits due to the small sample size.

Mechanisms underlying neonate-specific metabolic effects of volatile anesthetics

Volatile anesthetics (VAs) are widely used in medicine, but the mechanisms underlying their effects remain ill-defined. Though routine anesthesia is safe in healthy individuals, instances of sensitivity are well documented, and there has been significant concern regarding the impact of VAs on neonatal brain development. Evidence indicates that VAs have multiple targets, with anesthetic and non-anesthetic effects mediated by neuroreceptors, ion channels, and the mitochondrial electron transport chain. Here, we characterize an unexpected metabolic effect of VAs in neonatal mice. Neonatal blood β-hydroxybutarate (β-HB) is rapidly depleted by VAs at concentrations well below those necessary for anesthesia. β-HB in adults, including animals in dietary ketosis, is unaffected. Depletion of β-HB is mediated by citrate accumulation, malonyl-CoA production by acetyl-CoA carboxylase, and inhibition of fatty acid oxidation. Adults show similar significant changes to citrate and malonyl-CoA, but are insensitive to malonyl-CoA, displaying reduced metabolic flexibility compared to younger animals.

Is It Definitely Clear That Long-Term Survival after Breast Cancer Surgery Is Not Affected by Anaesthetics?

Retrospective studies indicate that cancer survival may be affected by the anaesthetic technique. Propofol seems to be a better choice than volatile anaesthetics, such as sevoflurane. The first two retrospective studies suggested better long-term survival with propofol, but not for breast cancer. Subsequent retrospective studies from Asia indicated the same. When data from seven Swedish hospitals were analysed, including 6305 breast cancer patients, different analyses gave different results, from a non-significant difference in survival to a remarkably large difference in favour of propofol, an illustration of the innate weakness in the retrospective design. The largest randomised clinical trial, registered on clinicaltrial.gov, with survival as an outcome is the Cancer and Anesthesia study. Patients are here randomised to propofol or sevoflurane. The inclusion of patients with breast cancer was completed in autumn 2017. Delayed by the pandemic, one-year survival data for the cohort were presented in November 2020. Due to the extremely good short-term survival for breast cancer, one-year survival is of less interest for this disease. As the inclusions took almost five years, there was also a trend to observe. Unsurprisingly, no difference was found in one-year survival between the two groups, and the trend indicated no difference either.

Hypoxia-dependent signaling in perioperative and critical care medicine

A critical goal of patient management for anesthesiologists and intensivists is to maintain oxygen homeostasis in patients admitted to operation theaters and intensive care units. For this purpose, it is imperative to understand the strategies of the body against oxygen imbalance—especially oxygen deficiency (hypoxia). Adaptation to hypoxia and maintenance of oxygen homeostasis involve a wide range of responses that occur at different organizational levels in the body. These responses are greatly influenced by perioperative patient management including factors such as perioperative drugs. Herein, the influence of perioperative patient management on the body's response to oxygen imbalance was reviewed with a special emphasis on hypoxia-inducible factors (HIFs), transcription factors whose activity are regulated by the perturbation of oxygen metabolism. The 2019 Nobel Prize in Physiology or Medicine was awarded to three researchers who made outstanding achievements in this field. While previous studies have reported the effect of perioperatively used drugs on hypoxia-induced gene expression mediated by HIFs, this review focused on effects of subacute or chronic hypoxia changes in gene expression that are mediated by the transcriptional regulator HIFs. The clinical implications and perspectives of these findings also will be discussed. Understanding the basic biology of the transcription factor HIF can be informative for us since anesthesiologists manage patients during the perioperative period facing the imbalances the oxygen metabolism in organ and tissue. The clinical implications of hypoxia-dependent signaling in critical illness, including Coronavirus disease (COVID-19), in which disturbances in oxygen metabolism play a major role in its pathogenesis will also be discussed.

Influence of MRI Examinations on Animal Welfare and Study Results

OBJECTIVES

Magnetic resonance imaging (MRI) is considered to be well tolerated by laboratory animals. However, no systematic study has been performed yet, proving this assumption. Therefore, the aim of this study was to investigate the possible effects of longitudinal native and contrast-enhanced (CE) 1-T and 7-T MRI examinations on mouse welfare as well as 4T1 breast cancers progression and therapy response.

MATERIAL AND METHODS

Forty-seven healthy and 72 breast cancer-bearing mice (4T1) were investigated. One-Tesla (ICON) and 7-T (Biospec) MRI measurements were performed thrice per week under isoflurane anesthesia in healthy BALB/c mice for 4 weeks and 3 times within 2 weeks in tumor-bearing animals. Animal welfare was examined by an observational score sheet, rotarod performance, heart rate measurements, and assessment of fecal corticosterone metabolites. Furthermore, we investigated whether CE-MRI influences the study outcome. Therefore, hemograms and organ weights were obtained, and 4T1 tumor growth, perfusion, immune cell infiltration, as well as response to the multikinase inhibitor regorafenib were investigated. Statistical comparisons between groups were performed using analysis of variance and Tukey or Bonferroni post hoc tests.

RESULTS

Mice showed no alterations in the observational score sheet rating, rotarod performance, heart rate, and fecal corticosterone metabolites (P > 0.05) after repeated MRI at both field strengths. However, spleen weights were reduced in all healthy mouse groups that received isoflurane anesthesia (P < 0.001) including the groups investigated by 1-T and 7-T MRI (P = 0.02). Neither tumor progression nor response to the regorafenib treatment was affected by isoflurane anesthesia or CE-MRI monitoring. Furthermore, immunohistological tumor analysis did not indicate an effect of isoflurane and MRI on macrophage infiltration of tumors, perfusion of tumor vessels, and apoptotic cell rate (P > 0.05).

CONCLUSIONS

Repeated MRI did not influence the welfare of mice and did not affect tumor growth and therapy response of 4T1 tumors. However, systemic immunological effects of isoflurane anesthesia need to be considered to prevent potential bias.

Anesthetic technique and cancer surgery outcomes

PURPOSE OF REVIEW

Surgery remains integral to treating solid cancers. However, the surgical stress response, characterized by physiologic perturbation of the adrenergic, inflammatory, and immune systems, may promote procancerous pathways. Anesthetic technique per se may attenuate/enhance these pathways and thereby could be implicated in long-term cancer outcomes.

RECENT FINDINGS

To date, clinical studies have predominantly been retrospective and underpowered and, thus limit meaningful conclusions. More recently, prospective studies of regional anesthesia for breast and colorectal cancer surgery have failed to demonstrate long-term cancer outcome benefit. However, based on the consistent observation of protumorigenic effects of surgical stress and that of volatile anesthesia in preclinical studies, supported by in vivo models of tumor progression and metastasis, we await robust prospective clinical studies exploring the role of propofol-based total intravenous anesthesia (cf. inhalational volatiles). Additionally, anti-adrenergic/anti-inflammatory adjuncts, such as lidocaine, nonsteroidal anti-inflammatory drugs and the anti-adrenergic propranolol warrant ongoing research.

SUMMARY

The biologic perturbation of the perioperative period, compounded by the effects of anesthetic agents, renders patients with cancer particularly vulnerable to enhanced viability of minimal residual disease, with long-term outcome consequences. However, low level and often conflicting clinical evidence equipoise currently exists with regards to optimal oncoanesthesia techniques. Large, prospective, randomized control trials are urgently needed to inform evidence-based clinical practice guidelines.

Implications of anesthesia and vaccination

The current COVID-19 pandemic has had a global impact on vaccination rates. Delays in routine healthcare and immunization have led to a rise in concerns about resurgence of vaccine-preventable diseases around the world. With the release and distribution of COVID-19 vaccines, plans to improve immunization rates need to be explored and implemented across disciplines. One approach would be the consideration of perioperative vaccinations; however, the effects of anesthesia and surgery on the immune response and complications associated with vaccination during the perioperative period are still poorly understood, and opinions are divided. To ascertain the value of a perioperative vaccination program, it is important to understand the basics of immunization and common vaccinations; the potential vaccine complications in the pediatric cohort; the implications of anesthesia and surgery on the immune response; and current recommendations. In addition, we believe it is important to discuss the logistics and feasibility of coordinating perioperative immunization should this become a regular opportunity.

Pharmacological and nutritional targeting of voltage-gated sodium channels in the treatment of cancers

Voltage-gated sodium (NaV) channels, initially characterized in excitable cells, have been shown to be aberrantly expressed in non-excitable cancer tissues and cells from epithelial origins such as in breast, lung, prostate, colon, and cervix, whereas they are not expressed in cognate non-cancer tissues. Their activity was demonstrated to promote aggressive and invasive potencies of cancer cells, both in vitro and in vivo, whereas their deregulated expression in cancer tissues has been associated with metastatic progression and cancer-related death. This review proposes NaV channels as pharmacological targets for anticancer treatments providing opportunities for repurposing existing NaV-inhibitors or developing new pharmacological and nutritional interventions.

Preconditioning increases brain resistance against acute brain injury via neuroinflammation modulation

Acute brain injury (ABI) is a broad concept mainly comprised of sudden parenchymal brain injury. Acute brain injury outcomes are dependent not only on the severity of the primary injury, but the delayed secondary injury that subsequently follows as well. These are both taken into consideration when determining the patient's prognosis. Growing clinical and experimental evidence demonstrates that "preconditioning," a prophylactic approach in which the brain is exposed to various pre-injury stressors, can induce varying degrees of "tolerance" against the impact of the ABI by modulating neuroinflammation. In this review, we will summarize the pathophysiology of ABI, and discuss the involved mechanisms of neuroinflammation in ABI, as well as existing experimental and clinical studies demonstrating the efficacy of preconditioning methods in various types of ABI by modulating neuroinflammation.

Sevoflurane represses the migration and invasion of gastric cancer cells by regulating forkhead box protein 3

OBJECTIVE

Previous studies suggested that sevoflurane exerts anti-proliferative, anti-migratory, and anti-invasive effects on cancer cells. To determine the role of sevoflurane on gastric cancer (GC) progression, we evaluated its effects on the proliferation, migration, and invasion of SGC7901, AGS, and MGC803 GC cells.

METHODS

GC cells were exposed to different concentrations of sevoflurane (1.7, 3.4, or 5.1% v/v). Cell viability, migration, and invasion were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Transwell assays. Immunohistochemical staining and immunoblotting were performed to analyze forkhead box protein 3 (FOXP3) protein expression in tissue specimens and cell lines, respectively.

RESULTS

FOXP3 was downregulated in human GC specimens and cell lines. Functionally, FOXP3 overexpression significantly inhibited the proliferation, migration, and invasion of GC cells and accelerated their apoptosis. Moreover, sevoflurane significantly blocked GC cell migration and invasion compared with the findings in the control group. However, FOXP3 silencing neutralized sevoflurane-induced apoptosis and the inhibition of GC cell migration and invasion. Sevoflurane-induced apoptosis and the suppression of migration and invasion might be associated with FOXP3 overactivation in GC cells.

CONCLUSIONS

Sevoflurane activated FOXP3 and prevented GC progression via inhibiting cell migration and invasion in vitro.

Association Between Anesthetic Dose and Technique and Oncologic Outcomes After Surgical Resection of Non-Small Cell Lung Cancer

OBJECTIVES

Because of the biologic effects of volatile anesthetics on the immune system and cancer cells, it has been hypothesized that their use during non-small cell lung cancer (NSCLC) surgery may negatively affect cancer outcomes compared with total intravenous anesthesia (TIVA) with propofol. The present study evaluated the relationship between anesthetic technique and dose and oncologic outcome in NSCLC surgery.

DESIGN

Retrospective cohort study.

SETTING

Surgical records collated from a single, tertiary care hospital and combined with the Scottish Cancer Registry and continuously recorded electronic anesthetic data.

PARTICIPANTS

Patients undergoing elective lung resection for NSCLC between January 2010 and December 2014.

INTERVENTIONS

The cohort was divided into patients receiving TIVA only and patients exposed to volatile anesthetics.

MEASUREMENTS AND MAIN RESULTS

Final analysis included 746 patients (342 received TIVA and 404 volatile anesthetic). Kaplan-Meier survival curves with log-rank testing were drawn for cancer-specific and overall survival. No significant differences were demonstrated for either cancer-specific (p = 0.802) or overall survival (p = 0.736). Factors influencing survival were analyzed using Cox proportional hazards modeling. Anesthetic type was not a significant predictor for cancer-specific or overall survival in univariate or multivariate Cox analysis. Volatile anesthetic exposure was quantified using area under the end-tidal expired anesthetic agent versus time curves. This was not significantly associated with cancer-specific survival on univariate (p = 0.357) or multivariate (p = 0.673) modeling.

CONCLUSIONS

No significant relationship was demonstrated between anesthetic technique and NSCLC survival. Whether a causal relationship exists between anesthetic technique during NSCLC surgery and oncologic outcome warrants definitive investigation in a prospective, randomized trial.

Inhaled Anesthetics: Environmental Role, Occupational Risk, and Clinical Use

Inhaled anesthetics have been in clinical use for over 150 years and are still commonly used in daily practice. The initial view of inhaled anesthetics as indispensable for general anesthesia has evolved during the years and, currently, its general use has even been questioned. Beyond the traditional risks inherent to any drug in use, inhaled anesthetics are exceptionally strong greenhouse gases (GHG) and may pose considerable occupational risks. This emphasizes the importance of evaluating and considering its use in clinical practices. Despite the overwhelming scientific evidence of worsening climate changes, control measures are very slowly implemented. Therefore, it is the responsibility of all society sectors, including the health sector to maximally decrease GHG emissions where possible. Within the field of anesthesia, the potential to reduce GHG emissions can be briefly summarized as follows: Stop or avoid the use of nitrous oxide (N2O) and desflurane, consider the use of total intravenous or local-regional anesthesia, invest in the development of new technologies to minimize volatile anesthetics consumption, scavenging systems, and destruction of waste gas. The improved and sustained awareness of the medical community regarding the climate impact of inhaled anesthetics is mandatory to bring change in the current practice.

Anesthesia and Long-term Oncological Outcomes: A Systematic Review and Meta-analysis

BACKGROUND

Whether propofol elicits a survival benefit over volatile anesthetics during cancer surgery remains inconclusive. The primary aim of this systematic review and meta-analysis is to compare the effects of propofol-based total intravenous anesthesia (TIVA) with any volatile anesthesia on long-term oncological outcomes. The secondary aim is to compare propofol-based TIVA with specific volatile agents on long-term oncological outcomes.

METHODS

We searched PubMed, Embase, Scopus, Web of Science, and Cochrane Library from inception through March 3, 2020. Randomized control trials and observational studies that compared the effects of propofol-based TIVA and volatile anesthesia on long-term oncological outcomes, which also reported hazard ratios (HR) as effect estimates, were considered eligible for inclusion. Using the inverse variance method with a random-effects model, HR and 95% confidence intervals (CI) were calculated. Trial sequential analysis was incorporated to test if the results were subject to a type I or type II error.

RESULTS

Nineteen retrospective observational studies were included. Patients who received propofol-based TIVA during cancer surgery were associated with significantly better overall survival than those who received volatile anesthesia (HR = 0.79, 95% CI, 0.66-0.94, P = .008, I2 = 82%). In contrast, no statistically significant difference was observed in recurrence-free survival between patients who received propofol-based TIVA and volatile anesthesia during cancer surgery (HR = 0.81, 95% CI, 0.61-1.07, P = .137, I2 = 85%). In the subgroup analysis by different volatile anesthetics, patients who received propofol-based TIVA were associated with better overall survival than those who received desflurane (HR = 0.54, 95% CI, 0.36-0.80, P = .003, I2 = 80%). In contrast, there was no statistically significant difference in overall survival between patients who received propofol-based TIVA and those who received sevoflurane (HR = 0.92, 95% CI, 0.74-1.14, P = .439, I2 = 70%). In the trial sequential analysis of overall survival, the cumulative Z curve reached the required heterogeneity-adjusted information size and crossed the traditional significance boundary. In contrast, in the trial sequential analysis of recurrence-free survival, the cumulative Z curve did not cross the traditional significance boundary. However, the required heterogeneity-adjusted information size has not yet been reached.

CONCLUSIONS

Propofol-based TIVA is generally associated with better overall survival than volatile anesthesia during cancer surgery. Further large-scaled, high-quality randomized control trials are warranted to confirm our findings.

Dietary Fucose Affects Macrophage Polarization and Reproductive Performance in Mice

Intestinal mucus protects epithelial and immune cells from the gut resident microorganisms, and provides growth-promoting factors as mucus-derived O-glycans for beneficial bacteria. A lack of intestinal protective mucus results in changes in the commensal microflora composition, mucosal immune system reprogramming, and inflammation. Previous work has shown that fucose, the terminal glycan chain component of the intestinal glycoprotein Mucin2, and fucoidan polysaccharides have an anti-inflammatory effect in some mouse models of colitis. This study evaluates the effect of fucose on reproductive performance in heterozygous mutant Muc2 female mice. We found that even though Muc2^+/− females are physiologically indistinguishable from C57Bl/6 mice, they have a significantly reduced reproductive performance upon dietary fucose supplementation. Metagenomic analysis reveals that the otherwise healthy wild-type siblings of Muc2^−/− animals have reduced numbers of some of the intestinal commensal bacterial species, compared to C57BL/6 mice. We propose that the changes in beneficial microflora affect the immune status in Muc2^+/− mice, which causes implantation impairment. In accordance with this hypothesis, we find that macrophage polarization during pregnancy is impaired in Muc2^+/− females upon addition of fucose. Metabolic profiling of peritoneal macrophages from Muc2^+/− females reveals their predisposition towards anaerobic glycolysis in favor of oxidative phosphorylation, compared to C57BL/6-derived cells. In vitro experiments on phagocytosis activity and mitochondrial respiration suggest that fucose affects oxidative phosphorylation in a genotype-specific manner, which might interfere with implantation depending on the initial status of macrophages. This hypothesis is further confirmed in BALB/c female mice, where fucose caused pregnancy loss and opposed implantation-associated M2 macrophage polarization. Taken together, these data suggest that intestinal microflora affects host immunity and pregnancy outcome. At the same time, dietary fucose might act as a differential regulator of macrophage polarization during implantation, depending on the immune status of the host.

A preliminary study to assess neutrophil and endothelial response to knee arthroplasty with the use of a tourniquet : effects of spinal or sevoflurane anesthesia

Background : During orthopedic surgery, the use of a pneumatic tourniquet results in side effects secondary to ischemia-reperfusion phenomena. We tested the hypothesis that total knee arthroplasty with a tourniquet is associated with increase in plasma concentrations of biomarkers of neutrophil activation and endothelial injury. The second aim was to compare these changes during spinal or general inhalational anesthesia. Methods : 40 adult ASA I-II patients scheduled for total knee arthroplasty with a tourniquet under spinal or sevoflurane anesthesia were included. Venous blood samples were collected before surgery, 1 h, 3 h, and 24 h after tourniquet deflation. To assess neutrophil activation, plasma concentrations of total and active fractions of myeloperoxidase, as well as elastase concentrations and proteolytic activity were measured. Endothelial injury was assessed by measurement of plasma concentrations of syndecan-1, soluble thrombomodulin, soluble E-selectin, and vascular endothelial growth factor. Results were analyzed with a two-way analysis of variance. P< 0.05 was considered statistically significant. Results : Plasma concentrations of active but not total myeloperoxidase and elastase significantly increased following tourniquet deflation. The level of syndecan-1, soluble thrombomodulin, soluble E-selectin, but not vascular endothelial growth factor, significantly decreased postoperatively. These changes of biomarkers were similar during spinal and sevoflurane anesthesia. Conclusions : Total knee arthroplasty with pneumatic tourniquet is associated with systemic release of markers of neutrophil activation which was comparable during spinal or sevoflurane anesthesia. Systemic expression of endothelial injury was not detected in our clinical conditions.

Phenylephrine impairs host defence mechanisms to infection: a combined laboratory study in mice and translational human study

BACKGROUND

Immunosuppression after surgery is associated with postoperative complications, mediated in part by catecholamines that exert anti-inflammatory effects via the β-adrenergic receptor. Phenylephrine, generally regarded as a selective α-adrenergic agonist, is frequently used to treat perioperative hypotension. However, phenylephrine may impair host defence through β-adrenergic affinity.

METHODS

Human leukocytes were stimulated with lipopolysaccharide (LPS) in the presence or absence of phenylephrine and α- and β-adrenergic antagonists. C57BL/6J male mice received continuous infusion of phenylephrine (30-50 μg kg-1 min-1 i.v.) or saline via micro-osmotic pumps, before LPS administration (5 mg kg-1 i.v.) or caecal ligation and puncture (CLP). Twenty healthy males were randomised to a 5 h infusion of phenylephrine (0.5 μg kg-1 min-1) or saline before receiving LPS (2 ng kg-1 i.v.).

RESULTS

In vitro, phenylephrine enhanced LPS-induced production of the anti-inflammatory cytokine interleukin (IL)-10 (maximum augmentation of 93%) while attenuating the release of pro-inflammatory mediators. These effects were reversed by pre-incubation with β-antagonists, but not α-antagonists. Plasma IL-10 levels were higher in LPS-challenged mice infused with phenylephrine, whereas pro-inflammatory mediators were reduced. Phenylephrine infusion increased bacterial counts after CLP in peritoneal fluid (+42%, P=0.0069), spleen (+59%, P=0.04), and liver (+35%, P=0.09). In healthy volunteers, phenylephrine enhanced the LPS-induced IL-10 response (+76%, P=0.0008) while attenuating plasma concentrations of pro-inflammatory mediators including IL-8 (-15%, P=0.03).

CONCLUSIONS

Phenylephrine exerts potent anti-inflammatory effects, possibly involving the β-adrenoreceptor. Phenylephrine promotes bacterial outgrowth after surgical peritonitis. Phenylephrine may therefore compromise host defence in surgical patients and increase susceptibility towards infection.

CLINICAL TRIAL REGISTRATION

NCT02675868 (Clinicaltrials.gov).

The immunomodulatory effect of ketamine in colorectal cancer surgery: a randomized-controlled trial

PURPOSE

Ketamine's inhibitory action on the N-methyl-D-aspartate receptor and anti-inflammatory effects may provide beneficial immunomodulation in cancer surgery. We investigated the effect of subanesthetic-dose ketamine as an adjunct to desflurane anesthesia on natural killer (NK) cell activity and inflammation in patients undergoing colorectal cancer surgery.

METHODS

A total of 100 patients were randomly assigned to a control or ketamine group. The ketamine group received a bolus of 0.25 mg·kg^-1 ketamine five minutes before the start of surgery, followed by an infusion 0.05 mg·kg^-1·hr^-1 until the end of surgery; the control group received a similar amount of normal saline. We measured NK cell activity and proinflammatory cytokines (interleukin-6 [IL-6] and tumour necrosis factor-α [TNF-α]) before surgery and one, 24, and 48 hr after surgery. C-reactive protein (CRP) was measured before surgery and one, three, and five days after surgery. Carcinoembryonic antigen and cancer recurrence/metastasis were assessed two years after surgery.

RESULTS

The NK cell activity was significantly decreased after surgery in both groups, but the change was not different between groups in the linear mixed model analysis (P = 0.47). Changes in IL-6, TNF-α, CRP, and carcinoembryonic antigen levels were not different between groups (P = 0.27, 0.69, 0.99, and 0.97, respectively). Cancer recurrence within 2 years after surgery was similar between groups (10% vs 8%, P = 0.62).

CONCLUSIONS

Intraoperative low-dose ketamine administration did not convey any favourable impacts on overall postoperative NK cell activity, inflammatory responses, and prognosis in colorectal cancer surgery patients.

TRIAL REGISTRATION

www.clinicaltrial.gov (NCT03273231); registered 6 September 2017.

The role of regional anaesthesia in the emerging subspecialty of onco-anaesthesia: a state-of-the-art review

Cancer accounts for millions of deaths globally each year, predominantly due to recurrence and metastatic disease. The majority of patients with primary solid organ cancers require surgery, however, some degree of tumour dissemination related to surgery is inevitable. The surgical stress response and associated immunosuppression, pain, inflammation, tissue hypoxia and angiogenesis have all been implicated in promoting tumour survival, proliferation and recurrence. Regional anaesthesia was hypothesised to reduce the surgical stress response and immunosuppression, minimise the need for volatile anaesthesia and reduce pain and opioid requirements, thus mitigating pro-tumour pathways associated with the peri-operative period and improving long-term oncological outcomes. While some retrospective studies suggested an association between regional anaesthesia and reduced cancer recurrence, the first large randomised controlled trial on the effect of anaesthetic technique on cancer outcome found no significant difference between paravertebral regional anaesthesia and volatile anaesthesia with opioid analgesia in patients undergoing breast cancer surgery. Randomised controlled trials on the long-term oncological outcomes of regional anaesthesia in other tumour types are ongoing. The focus on how peri-operative interventions, especially regional anaesthesia, during cancer resection surgery, may enhance short-term recovery and perhaps influence long-term outcome has spawned the global emergence of the subspecialty of onco-anaesthesia. This review aims to discuss the most recent evidence on the use of regional anaesthesia in cancer surgery and the significance of its role in onco-anaesthesia.

Sedating Mechanically Ventilated COVID-19 Patients with Volatile Anesthetics: Insights on the Last-Minute Potential Weapons

Coronavirus Disease 2019 (COVID-19) has spread globally with the number of cases exceeding seventy million. Although trials on potential treatments of COVID-19 Acute Respiratory Distress Syndrome (ARDS) are promising, the introduction of an effective therapeutic intervention seems elusive. In this review, we explored the potential therapeutic role of volatile anesthetics during mechanical ventilation in the late stages of the disease. COVID-19 is thought to hit the human body via five major mechanisms: direct viral damage, immune overactivation, capillary thrombosis, loss of alveolar capillary membrane integrity, and decreased tissue oxygenation. The overproduction of pro-inflammatory cytokines will eventually lead to the accumulation of inflammatory cells in the lungs, which will lead to ARDS requiring mechanical ventilation. Respiratory failure resulting from ARDS is thought to be the most common cause of death in COVID-19. The literature suggests that these effects could be directly countered by using volatile anesthetics for sedation. These agents possess multiple properties that affect viral replication, immunity, and coagulation. They also have proven benefits at the molecular, cellular, and tissue levels. Based on the comprehensive understanding of the literature, short-term sedation with volatile anesthetics may be beneficial in severe stages of COVID-19 ARDS and trials to study their effects should be encouraged.

Effects of Sevoflurane on Lewis Lung Carcinoma Cell Proliferation In Vivo and In Vitro

Background and objectives: There are several studies that sevoflurane could enhance proliferation of cancer cells, while others suggest no effect on clinical outcome. We conducted in vivo and in vitro experiments to investigate the effects of sevoflurane, a volatile anesthetic, on proliferation and outcomes of Lewis lung carcinoma (LLC) cells. Materials and Methods: A total of 37 mice were injected with LLC cells to compare the tumor size and survival of the sevoflurane exposed group (sevo group) and control group. The sevo group was exposed to 2% sevoflurane and 4 L/min of oxygen for 1 h per day 3 times per week, and the control group was exposed only to 4 L/min of oxygen. In vitro study, 12 plates incubated with LCC cells. 6 plates were exposed to 2% sevoflurane for 1 hr/day for 3 days and 6 plates were not exposed, and cell proliferation was compared after 3 days. Results: There were no significant differences in survival or tumor size between mice exposed to sevoflurane and control mice (survival: 29.06 ± 4.45 vs. 28.76 ± 3.75, p = 0.836; tumor size: 0.75 (0.41–1.02) vs. 0.49 (0.11–0.79), p = 0.153). However, in vitro study, the proliferation of LLC cells exposed to sevoflurane increased by 9.2% compared to the control group (p = 0.018). Conclusions: Sevoflurane (2 vol%) exposure could promote proliferation of LLC cells in vitro environment, but may not affect proliferation of LLC cells in vivo environment. These results suggest that in vitro studies on the effects of anesthetics on cancer may differ from those of in vivo or clinical studies.

The Role of Perioperative Sleep Disturbance in Postoperative Neurocognitive Disorders

Postoperative neurocognitive disorder (PND) increases the length of hospital stay, mortality, and risk of long-term cognitive impairment. Perioperative sleep disturbance is prevalent and commonly ignored and may increase the risk of PND. However, the role of perioperative sleep disturbances in PND remains unclear. Nocturnal sleep plays an indispensable role in learning, memory, and maintenance of cerebral microenvironmental homeostasis. Hospitalized sleep disturbances also increase the incidence of postoperative delirium and cognitive dysfunction. This review summarizes the role of perioperative sleep disturbances in PND and elucidates the potential mechanisms underlying sleep-deprivation-mediated PND. Activated neuroinflammation and oxidative stress; impaired function of the blood-brain barrier and glymphatic pathway; decreased hippocampal brain-derived neurotrophic factor, adult neurogenesis, and sirtuin1 expression; and accumulated amyloid-beta proteins are associated with PND in individuals with perioperative sleep disorders. These findings suggest that the improvement of perioperative sleep might reduce the incidence of postoperative delirium and postoperative cognitive dysfunction. Future studies should further investigate the role of perioperative sleep disturbance in PND.

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.

Inhalation or total intravenous anaesthesia and recurrence after colorectal cancer surgery: a propensity score matched Danish registry-based study

BACKGROUND

During colorectal cancer surgery, the immune-modulating effects of inhalation anaesthesia may create a favourable environment for metastasis formation, leading to increased risk of recurrence. Our aim was to assess the association between inhalation vs intravenous anaesthesia and cancer recurrence in patients undergoing colorectal cancer surgery.

METHODS

Patients undergoing colorectal cancer surgery in 2004-18 were identified in the Danish Colorectal Cancer Group Database and Danish Anaesthesia Database. After exclusion of patients with residual tumour registered in postoperative pathology reports, local endoscopic resections, and stent insertions, we classified patients according to exposure to inhalation anaesthesia. The primary outcome was recurrence (time to recurrence), whereas secondary outcomes were all-cause mortality (time to death) and disease-free survival (time to either recurrence or death). Events of recurrence and death were identified using The Danish Civil Registration System, Danish National Pathology Registry, and Danish National Patient Registry. The sub-distribution hazards approach was used to estimate hazard ratios (HRs) for recurrence, and Cox regression was used for all-cause mortality and disease-free survival.

RESULTS

We identified 5238 patients exposed to inhalation anaesthesia and 6322 to intravenous anaesthesia. Propensity score matching yielded 4347 individuals in each group with balanced baseline covariates. We found a weak association between recurrence and exposure to inhalation anaesthesia (HR=1.12; 95% confidence interval [CI], 1.02-1.23). The HR estimates for all-cause mortality and disease-free survival were 1.00 (95% CI, 0.93-1.07) and 1.04 (95% CI, 0.98-1.11) respectively.

CONCLUSION

Exposure to inhalation anaesthesia was associated with increased risk of recurrence after colorectal cancer surgery.

Effects of dexmedetomidine on immune response in patients undergoing radical and reconstructive surgery for oral cancer

Oral cancer is one of the most common malignancies in the world. The present study aimed to investigate the effects of dexmedetomidine on immune response in patients undergoing radical and reconstructive surgery for oral cancer. Patients were randomly divided into the dexmedetomidine and control groups. Within 15 min before anesthesia induction, dexmedetomidine was infused with a 0.5 µg·kg⁻¹ loading dose followed by a maintenance dose of 0.4 µg·kg⁻¹·h⁻¹ to the end of operation in the dexmedetomidine group, whereas the same volume of saline was administered in the control group. Blood samples were obtained at five time-points: 30 min Before induction (T₀), 1 h after induction (T₁), end of the operation (T₂) and 24 (T₃) and 48 h (T₄) after the operation. The T lymphocyte subsets (including CD3⁺, CD4⁺ and CD8⁺ cells) and CD4⁺/CD8⁺ ratio, B lymphocytes, dendritic cells and myeloid-derived suppressor cells (MDSCs) were analyzed by flow cytometry. All immunological indicators, except CD8⁺ cells, significantly decreased between the two groups at T_1–3 compared with T₀ (P<0.05). The percentages of CD3⁺, CD4⁺, dendritic cells and the CD4⁺/CD8⁺ ratios were significantly higher at T_2–4 and the percentages of MDSCs were significantly lower at T_2–4 in the dexmedetomidine group compared with the control group (all P<0.05). These findings suggested that dexmedetomidine can attenuate immunosuppression in patients undergoing radical and reconstructive surgery for oral cancer.

Chemocentric Informatics Analysis: Dexamethasone Versus Combination Therapy for COVID-19

COVID-19 is a biphasic infectious disease with no approved vaccine or pharmacotherapy. The first drug that has shown promise in reducing COVID-19 mortality in severely-ill patients is dexamethasone, a cheap, well-known anti-inflammatory glucocorticoid, approved for the treatment of inflammatory conditions including respiratory diseases such as asthma and tuberculosis. However, about 80% of COVID-19 patients requiring oxygenation, and about 67% of patients on ventilators, are not responsive to dexamethasone therapy mainly. Additionally, using higher doses of dexamethasone for prolonged periods of time can lead to severe side effects and some patients may develop corticosteroid resistance leading to treatment failure. In order to increase the therapeutic efficacy of dexamethasone in COVID-19 patients, while minimizing dexamethasone-related complications that could result from using higher doses of the drug, we applied a chemocentric informatics approach to identify combination therapies. Our results indicated that combining dexamethasone with fast long-acting beta-2 adrenergic agonists (LABAs), such as formoterol and salmeterol, can ease respiratory symptoms hastily, until dexamethasone's anti-inflammatory and immunosuppressant effects kick in. Our studies demonstrated that LABAs and dexamethasone (or other glucocorticoids) exert synergistic effects that will augment both anti-inflammatory and fibronectin-mediated anticoagulant effects. We also propose other alternatives to LABAs that are supported by sound systems biology evidence, such as nitric oxide. Other drugs such as sevoflurane and treprostinil interact with the SARS-CoV-2 interactome and deserve further exploration. Moreover, our chemocentric informatics approach provides systems biology evidence that combination therapies for COVID-19 will have higher chances of perturbing the SARS-CoV-2 human interactome, which may negatively impact COVID-19 disease pathways.

Outpatient breast-conserving surgery for breast cancer: Use of local and intravenous anesthesia and/or sedation may reduce recurrence and improve survival

The use of general anesthesia (GA) with inhalational anesthetics for breast cancer surgery may be associated with breast cancer recurrence and increased mortality due to the immunosuppressive effects of these drugs. Less-immunosuppressive anesthetic techniques may reduce breast cancer recurrence. We evaluated the feasibility, safety, and efficacy of outpatient breast-conserving surgery (BCS) for breast cancer in a breast clinic in terms of the anesthetic technique used, complications occurring, recurrence, and survival. Methods: The sample comprised 456 consecutive patients with stage 0–III breast cancer who underwent BCS/axillary lymph node (ALN) management using local and intravenous anesthesia and/or sedation between May 2008 and January 2020. Most patients received adjuvant chemotherapy and/or endocrine therapy and radiotherapy after surgery. Patient outcomes were evaluated retrospectively. Results: All patients recovered and were discharged after resting for 3–4 h postoperatively. No procedure-related severe complication or death occurred. Sixty-four complications (14.0%) were observed: 14 wound infections, 17 hematomas, and 33 axillary lymphoceles. The median follow-up period was 2259 days (range, 9–4190 days), during which disease recurrence was observed in 25 (5.4%) patients. The overall survival and breast cancer–specific survival rates were 92.3% and 94.7%, respectively. Conclusions: Outpatient surgery for breast cancer involving BCS and ALN management under local and intravenous anesthesia and/or sedation can be performed safely, without serious complication or death. Less-immunosuppressive anesthetic techniques with spontaneous breathing may reduce the recurrence of breast cancer and improve survival relative to GA.

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Outpatient surgery for breast cancer involving breast-conserving surgery (BCS) and axillary lymph node (ALN) management under local and intravenous anesthesia and/or sedation can be performed safely.

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Less-immunosuppressive anesthetic techniques with spontaneous breathing may reduce the recurrence of breast cancer and improve survival compared with general anesthesia.

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.

Perioperative and anesthetic risk factors of surgical site infection in patients undergoing pancreaticoduodenectomy: A retrospective cohort study

Background

Surgical site infection is a major perioperative issue. The morbidity of surgical site infection is high in major digestive surgery, such as pancreaticoduodenectomy. The comprehensive risk factors, including anesthetic factors, for surgical site infection in pancreaticoduodenectomy are unknown. The aim of this study was to investigate the perioperative and anesthetic risk factors of surgical site infection in pancreaticoduodenectomy.

Methods

This was a retrospective cohort study conducted in a single tertiary care center. A total of 326 consecutive patients who underwent pancreaticoduodenectomy between January 2009 and March 2018 were evaluated. Patients who underwent resection of other organs were excluded. The primary outcome was the incidence of surgical site infection, based on a Clavien-Dindo classification of grade 2 or higher. Multivariable logistic regression analysis was performed to investigate the association between surgical site infection and perioperative and anesthetic factors.

Results

Of the 326 patients, 116 (35.6%) were women. The median age was 70 years (interquartile range; 64–75). The median duration of surgery was 10.9 hours (interquartile range; 9.5–12.4). Surgical site infection occurred in 60 patients (18.4%). The multivariable analysis revealed that the use of desflurane as a maintenance anesthetic was associated with a significantly lower risk of surgical site infection than sevoflurane (odds ratio, 0.503; 95% confidence interval [CI], 0.260–0.973). In contrast, the duration of surgery (odds ratio, 1.162; 95% CI, 1.017–1.328), cerebrovascular disease (odds ratio, 3.544; 95% CI, 1.326–9.469), and ischemic heart disease (odds ratio, 10.839; 95% CI, 1.887–62.249) were identified as significant risk factors of surgical site infection.

Conclusions

Desflurane may be better than sevoflurane in preventing surgical site infection in pancreaticoduodenectomy. Cerebrovascular disease and ischemic heart disease are potential newly-identified risk factors of surgical site infection in pancreaticoduodenectomy.

Role of neuraxial drug delivery in cancer pain therapy

Opioids have long been the mainstay of cancer pain treatment and have been used without any consideration for their effect on cancer growth and long-term prognosis. There is now growing evidence that the continued use of opioids for this indication should be reviewed and even reconsidered. Although current evidence and literature covering this subject is mixed and does not yet allow for a clear determination to be made about safety, there is enough data to support the search for new treatment paradigms, beginning with anesthesia for oncologic surgery and management of cancer pain over the disease course.