Inhibition of the neutrophil oxidative response by propofol

Impact of prognostic nutritional index change on prognosis after colorectal cancer surgery under propofol or sevoflurane anesthesia

BACKGROUND

The alteration of the prognostic nutritional index (PNI) or the utilization of distinct anesthesia strategies has been linked to the prognosis of various cancer types, but the existing evidence is limited and inconclusive, particularly for colorectal cancer (CRC). Our objective was to evaluate the association between PNI change and progression free survival (PFS) and overall survival (OS) in patients treated with CRC surgery after propofol-based or sevoflurane-based anesthesia.

METHODS

We conducted a retrospective analysis of 414 patients with CRC who underwent surgical resection. Among them, 165 patients received propofol-based total intravenous anesthesia (TIVA-P), while 249 patients received sevoflurane-based inhalation anesthesia (IA-S). The PNI change (ΔPNI) was calculated by subtracting the pre-surgery PNI from the post-surgery PNI, and patients were categorized into high (≥ -2.25) and low (< -2.25) ΔPNI groups. Univariate and multivariate analyses were employed to evaluate the effects of the two anesthesia methods, ΔPNI, and their potential interaction on PFS and OS.

RESULTS

The median duration of follow-up was 35.9 months (interquartile range: 18-60 months). The five-year OS rates were 63.0% in the TIVA-P group and 59.8% in the IA-S group (hazard ratio [HR]: 0.96; 95% confidence interval [CI]: 0.70-1.35; p = 0.864), while the five-year PFS rates were 55.8% and 51.0% (HR: 0.92; 95% CI: 0.68-1.26; p = 0.614), respectively. In comparison to patients in the low ΔPNI group, those in the high ΔPNI group exhibited a favorable association with both OS (HR: 0.57; 95% CI: 0.40-0.76; p < 0.001) and PFS (HR: 0.58; 95% CI: 0.43-0.79; p < 0.001). Stratified analysis based on ΔPNI revealed significant protective effects in the propofol-treated participants within the high ΔPNI group, whereas such effects were not observed in the low ΔPNI group, for both OS (p for interaction = 0.004) and PFS (p for interaction = 0.024).

CONCLUSIONS

Our data revealed that among patients who underwent CRC surgery, those treated with TIVA-P exhibited superior survival outcomes compared to those who received IA-S, particularly among individuals with a high degree of PNI change.

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.

Intraoperative immunomodulatory effects of sevoflurane versus total intravenous anesthesia with propofol in bariatric surgery (the OBESITA trial): study protocol for a randomized controlled pilot trial

Background

Obesity is associated with a chronic systemic inflammatory process. Volatile or intravenous anesthetic agents may modulate immune function, and may do so differentially in obesity. However, no study has evaluated whether these potential immunomodulatory effects differ according to type of anesthesia in obese patients undergoing laparoscopic bariatric surgery.

Methods/design

The OBESITA trial is a prospective, nonblinded, single-center, randomized, controlled clinical pilot trial. The trial will include 48 patients with a body mass index ≥ 35 kg/m², scheduled for laparoscopic bariatric surgery using sleeve or a Roux-en-Y gastric bypass technique, who will be allocated 1:1 to undergo general inhalational anesthesia with sevoflurane or total intravenous anesthesia (TIVA) with propofol. The primary endpoint is the difference in plasma interleukin (IL)-6 levels when comparing the two anesthetic agents. Blood samples will be collected prior to anesthesia induction (baseline), immediately after anesthetic induction, and before endotracheal extubation. Levels of other proinflammatory and anti-inflammatory cytokines, neutrophil chemotaxis, macrophage differentiation, phagocytosis, and occurrence of intraoperative and postoperative complications will also be evaluated.

Discussion

To our knowledge, this is the first randomized clinical trial designed to compare the effects of two different anesthetics on immunomodulation in obese patients undergoing laparoscopic bariatric surgery. Our hypothesis is that anesthesia with sevoflurane will result in a weaker proinflammatory response compared to anesthesia with propofol, with lower circulating levels of IL-6 and other proinflammatory mediators, and increased macrophage differentiation into the M2 phenotype in adipose tissue.

Trial registration

Registro Brasileiro de Ensaios Clínicos, RBR-77kfj5. Registered on 25 July 2018.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3399-z) contains supplementary material, which is available to authorized users.

Propofol elicits autophagy via endoplasmic reticulum stress and calcium exchange in C2C12 myoblast cell line

In this study, we investigated the relationship between propofol and autophagy and examined whether this relationship depends on ER stress, production of ROS (reactive oxygen species), and disruption of calcium (Ca2+) homeostasis. To this end, we measured C2C12 cell apoptosis in vitro, along with Ca2+ levels; ROS production; and expression of proteins and genes associated with autophagy, Ca2+ homeostasis, and ER stress, including LC3 (microtubule-associate protein 1 light chain 3), p62, AMPK (adenosine 5'-monophosphate (AMP)-activated protein kinase), phosphorylated AMPK, mTOR (the mammalian target of rapamycin), phosphorylated mTOR, CHOP (C/BEP homologous protein), and Grp78/Bip (78 kDa glucose-regulated protein). We found that propofol treatment induced autophagy, ER stress, and Ca2+ release. The ratio of phosphorylated AMPK to AMPK increased, whereas the ratio of phosphorylated mTOR to mTOR decreased. Collectively, the data suggested that propofol induced autophagy in vitro through ER stress, resulting in elevated ROS and Ca2+. Additionally, co-administration of an ER stress inhibitor blunted the effect of propofol.

Uncontrolled sepsis: a systematic review of translational immunology studies in intensive care medicine

BACKGROUND

The design of clinical immunology studies in sepsis presents several fundamental challenges to improving the translational understanding of pathologic mechanisms. We undertook a systematic review of bed-to-benchside studies to test the hypothesis that variable clinical design methodologies used to investigate immunologic function in sepsis contribute to apparently conflicting laboratory data, and identify potential alternatives that overcome various obstacles to improve experimental design.

METHODS

We performed a systematic review of the design methodology employed to study neutrophil function (respiratory burst), monocyte endotoxin tolerance and lymphocyte apoptosis in the intensive care setting, over the past 15 years. We specifically focussed on how control samples were defined, taking into account age, gender, ethnicity, concomitant therapies, timing of sample collection and the criteria used to diagnose sepsis.

RESULTS

We identified 57 eligible studies, the majority of which (74%) used case-control methodology. Healthy volunteers represented the control population selected in 83% of studies. Comprehensive demographic data on age, gender and ethnicity were provided in ≤48% of case control studies. Documentation of diseases associated with immunosuppression, malignancy and immunomodulatory therapies was rare. Less than half (44%) of studies undertook independent adjudication for the diagnosis of sepsis while 68% provided microbiological data. The timing of sample collection was defined by highly variable clinical criteria. By contrast, surgical studies avoided many such confounders, although only one study in surgical patients monitored the study group for development of sepsis.

CONCLUSIONS

We found several important and common limitations in the clinical design of translational immunologic studies in human sepsis. Major elective surgery overcame many of these methodological limitations. The failure of adequate clinical design in mechanistic studies may contribute to the lack of translational therapeutic progress in intensive care medicine.

Propofol inhibits superoxide production, elastase release, and chemotaxis in formyl peptide-activated human neutrophils by blocking formyl peptide receptor 1

Neutrophils play a critical role in acute and chronic inflammatory processes, including myocardial ischemia/reperfusion injury, sepsis, and adult respiratory distress syndrome. Binding of formyl peptide receptor 1 (FPR1) by N-formyl peptides can activate neutrophils and may represent a new therapeutic target in either sterile or septic inflammation. Propofol, a widely used i.v. anesthetic, has been shown to modulate immunoinflammatory responses. However, the mechanism of propofol remains to be established. In this study, we showed that propofol significantly reduced superoxide generation, elastase release, and chemotaxis in human neutrophils activated by fMLF. Propofol did not alter superoxide generation or elastase release in a cell-free system. Neither inhibitors of γ-aminobutyric acid receptors nor an inhibitor of protein kinase A reversed the inhibitory effects of propofol. In addition, propofol showed less inhibitory effects in non-FPR1-induced cell responses. The signaling pathways downstream from FPR1, involving calcium, AKT, and ERK1/2, were also competitively inhibited by propofol. These results show that propofol selectively and competitively inhibits the FPR1-induced human neutrophil activation. Consistent with the hypothesis, propofol inhibited the binding of N-formyl-Nle-Leu-Phe-Nle-Tyr-Lys-fluorescein, a fluorescent analog of fMLF, to FPR1 in human neutrophils, differentiated THP-1 cells, and FPR1-transfected human embryonic kidney-293 cells. To our knowledge, our results identify, for the first time, a novel anti-inflammatory mechanism of propofol by competitively blocking FPR1 in human neutrophils. Considering the importance of N-formyl peptides in inflammatory processes, our data indicate that propofol may have therapeutic potential to attenuate neutrophil-mediated inflammatory diseases by blocking FPR1.

Effects of desflurane, sevoflurane and propofol on phagocytosis and respiratory burst activity of human polymorphonuclear leucocytes in bronchoalveolar lavage

BACKGROUND AND OBJECTIVE

In polymorphonuclear leucocytes, phagocytosis and respiratory burst activity are mainly responsible for bacterial killing. We aimed to investigate the effects of anaesthesia with desflurane, sevoflurane and propofol on these functional activities of polymorphonuclear leucocytes in bronchoalveolar lavage fluid.

METHODS

Sixty patients scheduled to have tympanoplasty surgery were studied. The patients were divided into three groups (group D, desflurane; group S, sevoflurane; group P, propofol). Anaesthesia was induced with propofol, fentanyl and rocuronium in all groups. Anaesthesia was maintained with inhalation agent or propofol. Bronchoalveolar lavage was performed immediately after induction of anaesthesia and after surgical procedure by a fibreoptic bronchoscope. Leucocyte respiratory burst and phagocytic activity in bronchoalveolar lavage fluid were determined by flow cytometric analysis of gated leucocyte populations within 2 h after each bronchoalveolar lavage sample. Changes in leucocyte functions with time were expressed as mean fluorescence intensity.

RESULTS

There were no significant differences in phagocytic activity of polymorphonuclear leucocytes within and between the groups. The respiratory burst function of polymorphonuclear leucocytes showed a significant increase after surgery in group P (P < 0.05). When we compared the differences between the three groups, we found the difference in mean fluorescence intensity as statistically significant between group P and group S.

CONCLUSION

This study showed that propofol anaesthesia increased the respiratory burst function of polymorphonuclear leucocytes in bronchoalveolar lavage fluid.

Propofol lipidic infusion promotes resistance to antifungals by reducing drug input into the fungal cell

Background

The administration of non-antifungal drugs during patient hospitalization might be responsible for discrepancies between in vitro and in vivo susceptibility to antifungals. Propofol is often administered to intensive care units as a sedative.

The purpose of this study was to evaluate the effect of propofol lipidic infusion upon the growth and susceptibility profile of pathogenic fungi.

Candida and Aspergillus were studied regarding the ability to grow and its susceptibility profile to antifungals in the presence of propofol infusion (Fresenius^®) (1.25, 2.5 and 5 mg.ml^-1) and its lipidic vehicle. The intensity of fluorescence after staining with FUN1, in the presence and absence of propofol infusion, was determined by flow cytometry. Radioactivity assays were also performed in order to quantify the input of [³H]- itraconazole into the fungal cell in the presence of propofol. Assays were repeated after addition of sodium azide, in order to block efflux pumps.

Results

Propofol infusion promoted budding of Candida and the germination of Aspergillus, latter forming a lipid layer around the hypha. An increase of minimal fungicidal concentrations regarding both Candida and Aspergillus strains was found for all antifungals when incubated simultaneously with propofol infusion. A decrease of the intensity of fluorescence of Candida cells was systematically observed, as well as a significant reduced intracellular uptake of [³H] itraconazole in cells treated with propofol infusion, even after the blockade of efflux pumps. The results obtained when testing with the lipid vehicle were similar.

Conclusion

Propofol infusion, due to its lipidic vehicle, increased the fungal germination and promoted resistance to antifungals. This effect seems to be related to the reduced access and/or permeabilization to fungal cells by antifungals.