The effects of sevoflurane and desflurane in vitro on platelet-leukocyte adhesion in whole blood

The deleterious impact of exposure to different inhaled anesthetics is time dependent

In this study, the effects of exposure to isoflurane, sevoflurane and desflurane on the oxidative response and inflammation at different times was analyzed in the lungs of adult C57BL/6 mice. 120 animals were divided into 3 groups (n = 40): Isoflurane (ISO), Sevoflurane (SEV) and Desflurane (DES) and exposed to these anesthetics for 1 h (n = 10), 2 h (n = 10) and 3 h (n = 10), at a minimum alveolar concentration (MAC) equal to 1. The control group (CG) (n = 10) was exposed to ambient air. 24 h after the experimental protocol, the animals were euthanized and the bronchoalveolar lavage fluid (BALF), blood and lung tissue samples were collected. In the BALF, animals exposed to isoflurane for 2 h and 3 h showed a greater influx of leukocytes, especially macrophages compared to the CG. The ISO3h had lower leukocyte counts in the peripheral blood compared to CG, ISO1h and ISO2h. There was an increase in CCL-2 levels in the ISO3h compared to the CG. Superoxide dismutase activity was higher in ISO1h compared to CG. The activity of catalase was higher in the ISO1h and ISO2h compared to the CG. The lipid peroxidation, as well as carbonylated protein were higher in the ISO3h compared to the CG (p < 0.05). Similar results were observed in the exposure of SEV and DES compared to inflammation and redox imbalance in different periods. This study demonstrated that time is a determinant to promote a local and systemic inflammatory response to different inhalational anesthetics in a healthy murine model.

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.

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.

In silico repositioning of approved drugs against Schistosoma mansoni energy metabolism targets

Schistosomiasis is a neglected parasitosis caused by Schistosoma spp. Praziquantel is used for the chemoprophylaxis and treatment of this disease. Although this monotherapy is effective, the risk of resistance and its low efficiency against immature worms compromises its effectiveness. Therefore, it is necessary to develop new schistosomicide drugs. However, the development of new drugs is a long and expensive process. The repositioning of approved drugs has been proposed as a quick, cheap, and effective alternative to solve this problem. This study employs chemogenomic analysis with use of bioinformatics tools to search, identify, and analyze data on approved drugs with the potential to inhibit Schistosoma mansoni energy metabolism enzymes. The TDR Targets Database, Gene DB, Protein, DrugBank, Therapeutic Targets Database (TTD), Promiscuous, and PubMed databases were used. Fifty-nine target proteins were identified, of which 18 had one or more approved drugs. The results identified 20 potential drugs for schistosomiasis treatment; all approved for use in humans.

Pulmonary static inflation with 50% xenon attenuates decline in tissue factor in patients undergoing Stanford type A acute aortic dissection repair

Background

The Stanford type A acute aortic dissection (AAD) carries a high risk of mortality and morbidity, and patients undergoing AAD surgery often bleed excessively and require blood products and transfusions. Thus, we studied how xenon alters coagulation using thromboelastography (TEG) and conventional hemostatic tests for patients with AAD undergoing aortic arch surgery involving cardiopulmonary bypass (CPB)/deep hypothermic circulatory arrest (DHCA).

Methods

This prospective single-center nonrandomized controlled clinical trial, registered in the Chinese Clinical Trial Registry (ChiCTR-ICR-15006435), assessed perioperative clinical variables and serological results from 50 subjects undergoing pulmonary static inflation with 50% nitrogen/50% oxygen from January 2013 to January 2014 and 50 subjects undergoing pulmonary static inflation with 50% xenon/50% oxygen from January 2014 to December 2014 during CPB for Stanford type A AAD. Repeated measures ANOVA were used to identify the effects of xenon on coagulation after surgery. The primary endpoint was perioperative changes in coagulation and fibrinolysis after intubation and 10 minutes, and 6 hours after the operation. The secondary endpoint was to assess the perioperative changes in serum level of tissue factor (TF), tissue factor pathway inhibitor (TFPI) and tissue plasminogen activator (tPA) after intubation and 10 minutes, and 6 hours after the operation.

Results

Mean prothrombin time (PT), activated partial thromboplastin time (APTT), international normalized ratio (INR), median fibrinogen degradation product (FDP), and D-dimer peaked and then decreased over 6 hours after surgery. TEG followed a similar trend. From the start to the end of surgery and until 6 h after surgery, mean TF decreased in controls (β -2.61, P<0.001 and β -2.83, P<0.001, respectively), but was maintained relatively stable in xenon group (β -0.5, P<0.001 and β -0.96, P<0.001, respectively).

Conclusions

Deterioration of coagulation function and activated fibrinolysis was confirmed by conventional tests and TEG analysis after Stanford type A AAD repair. Pulmonary static inflation with 50% xenon attenuates decline in TF in patients undergoing Stanford type A AAD repair.

Immune Modulation by Volatile Anesthetics

Volatile general anesthetics continue to be an important part of clinical anesthesia worldwide. The impact of volatile anesthetics on the immune system has been investigated at both mechanistic and clinical levels, but previous studies have returned conflicting findings due to varied protocols, experimental environments, and subject species. While many of these studies have focused on the immunosuppressive effects of volatile anesthetics, compelling evidence also exists for immunoactivation. Depending on the clinical conditions, immunosuppression and activation due to volatile anesthetics can be either detrimental or beneficial. This review provides a balanced perspective on the anesthetic modulation of innate and adaptive immune responses as well as indirect effectors of immunity. Potential mechanisms of immunomodulation by volatile anesthetics are also discussed. A clearer understanding of these issues will pave the way for clinical guidelines that better account for the impact of volatile anesthetics on the immune system, with the ultimate goal of improving perioperative management.

Low-Dose Sevoflurane May Reduce Blood Loss and Need for Blood Products After Cardiac Surgery: A Prospective, Randomized Pilot Study

Patients undergoing cardiac surgery often experience abnormal bleeding, due primarily to cardiopulmonary bypass (CPB)-induced activation of platelets. Sevoflurane may inhibit platelet activation, raising the possibility that administering it during CPB may reduce blood loss.Patients between 18 and 65 years old who were scheduled for cardiac surgery under CPB at our hospital were prospectively enrolled and randomized to receive intravenous anesthetics alone (control group, n = 77) or together with sevoflurane (0.5-1.0 vol/%) from an oxygenator (sevoflurane group, n = 76). The primary outcome was postoperative blood loss, the secondary outcome was postoperative need for blood products.Volume of blood loss was 48% lower in the sevoflurane group than the control group at 4 hours after surgery, and 33% lower at 12 hours after surgery. Significantly fewer patients in the sevoflurane group lost >700 mL blood within 24 hours (9 of 76 vs 28 of 77, P < 0.001). As a result, the sevoflurane group received significantly smaller volumes of packed red blood cells (1.25 ± 2.36 vs 2.23 ± 3.75 units, P = 0.011) and fresh frozen plasma (97 ± 237 vs 236 ± 344 mL, P = 0.004). Thus the sevoflurane group was at significantly lower risk of requiring complex blood products after surgery (adjusted odds ratio [OR] 0.34, 95% confidence interval [CI] 0.17-0.68, P = 0.002).Sevoflurane inhalation from an oxygenator during CPB may reduce blood loss and need for blood products after cardiac surgery.

Platelet flow cytometry

Flow cytometry is a powerful and versatile tool which can be used to provide substantial phenotypic data on platelets by yielding quantitative information of their physical and antigenic properties. This includes surface expression of functional receptors, bound ligands, expression of granule components, interaction of platelets with other platelets via aggregation, or interaction with other blood components, such as leukocytes or the plasma coagulation system. Quantitative assessment of these parameters may facilitate the diagnosis of inherited or acquired platelet disorders, assist in the diagnosis of diseases associated with platelet activation, or assist in the monitoring of safety and efficacy of antiplatelet therapy.

Sevoflurane reduces clinical disease in a mouse model of multiple sclerosis

Background

Inhalational anesthetics have been shown to influence T cell functions both in vitro and in vivo, in many cases inducing T cell death, suggesting that exposure to these drugs could modify the course of an autoimmune disease. We tested the hypothesis that in mice immunized to develop experimental autoimmune encephalomyelitis (EAE), a well established model of multiple sclerosis (MS), treatment with the commonly used inhalational anesthetic sevoflurane would attenuate disease symptoms.

Methods

C57Bl6 female mice were immunized with myelin oligodendrocyte glycoprotein (MOG) peptide residues 35 to 55 to induce a chronic demyelinating disease. At day 10 after immunization, the mice were subjected to 2 h of 2.5% sevoflurane in 100% oxygen, or 100% oxygen, alone. Following treatment, clinical scores were monitored up to 4 weeks, after which brain histology was performed to measure the effects on astrocyte activation and lymphocyte infiltration. Effects of sevoflurane on T cell activation were studied using splenic T cells isolated from MOG peptide-immunized mice, restimulated ex vivo with MOG peptide or with antibodies to CD3 and CD28, and in the presence of different concentrations of sevoflurane. T cell responses were assessed 1 day later by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for proliferation, lactate dehydrogenase (LDH) release for cell death, and inflammatory activation by production of interleukin (IL)-17 and interferon (IFN)γ.

Results

Clinical scores in the oxygen-treated group increased until day 28 at which time they showed moderate to severe disease (average clinical score of 2.9). In contrast, disease progression in the sevoflurane-treated group increased to 2.1 at day 25, after which it remained unchanged until the end of the study. Immunohistochemical analysis revealed reduced numbers of infiltrating leukocytes and CD4⁺ cells in the CNS of the sevoflurane-treated mice, as well as reduced glial cell activation. In splenic T cells, low doses of sevoflurane reduced IFNγ production, cell proliferation, and increased LDH release.

Conclusions

These results are the first to show attenuation of EAE disease by an inhaled anesthetic and are consistent with previous reports that inhaled anesthetics, including sevoflurane, can suppress T cell activation that, in the context of autoimmune diseases such as MS, could lead to reduced clinical progression.

Delayed inhibition of agonist-induced granulocyte-platelet aggregation after low-dose sevoflurane inhalation in humans

BACKGROUND

Sevoflurane can be used as sedative-analgesic drug with endothelial protective properties. We tested whether low-dose sevoflurane inhalation provides sustained inhibition of detrimental granulocyte-platelet aggregation in humans.

METHODS

Ten healthy male volunteers were enrolled in this crossover study. Each subject inhaled sevoflurane for 1 h at 0.5-1 vol % end-tidal concentration in oxygen (50 vol %). Inhaling oxygen (50 vol %) alone served as control. Venous blood samples were collected at baseline before inhalation, immediately after inhalation, and 24 h thereafter, and were used for flow cytometry to determine platelet surface marker (CD41, CD42b, CD62P/P-selectin, and PAC-1) on platelets and granulocytes and for kaolin-induced clot formation, as assessed by thromboelastography. In flow cytometry experiments, platelets were stimulated with arachidonic acid (AA, 30 microM), adenosine diphosphate (ADP, 1 microM), and thrombin receptor agonist peptide-6 (TRAP-6, 6 microM).

RESULTS

AA, ADP, and TRAP-6 markedly increased the expression of CD62P on platelets, whereas CD42b (shedding) and PAC-1 (heterotypic conjugates) expression decreased. The amount of granulocyte-platelet aggregates increased upon agonist stimulation. Low-dose sevoflurane inhalation reduced ADP-induced CD62P expression on platelets 24 h after inhalation, and inhibited the formation of granulocyte-platelet aggregates under stimulation with AA and ADP after 1 and 24 h, and with TRAP-6 after 24 h compared with control. Inhibition of granulocyte-platelet aggregates was accompanied by reduced clot firmness 24 h after sevoflurane inhalation compared with control.

CONCLUSIONS

We demonstrated for the first time that inhaling low-dose sevoflurane (<1 vol % end-tidal) inhibits agonist-induced granulocyte-platelet interactions 24 h after administration and thus counteracts thromboinflammatory processes.

Comparison of the effects of desflurane and sevoflurane on the expression of platelet surface glycoproteins in unstimulated and adenosine diphosphate-induced platelets in vitro

STUDY OBJECTIVE

To compare the effects of one minimum alveolar concentration (MAC) desflurane and sevoflurane on the expression of CD42b (glycoprotein [GP] Ib), CD41 (GPIIb), CD61 (GPIIIa), CD62P (P-selectin), and CD63 in both unstimulated and adenosine diphosphate (ADP)-stimulated platelets in vitro.

SETTING

University laboratory.

SUBJECTS

15 healthy volunteers.

INTERVENTIONS

Platelet-rich plasma was obtained and divided into three groups: platelet-rich plasma exposed to air (group 1); air plus one MAC desflurane (6% vol; group 2), and air plus one MAC sevoflurane (2% vol; group 3), for 40 minutes. Percentage of antigen-positive cells (%(+)) mean channel fluorescence (MCF(Sigma)), and index of platelet activation for positive platelets (IPA(+)) as expression markers for GPIb, GPIIb, GPIIIa, P-selectin, and CD63, were measured.

MEASUREMENTS AND MAIN RESULTS

In unstimulated platelets, expression markers for GPIIb and GPIIIa were significantly lower in groups 2 and 3 than group 1 (P < 0.001). P-selectin expression markers were significantly higher in group 2 than in group 1 or group 3 (P < 0.016). CD63 expression markers were significantly lower in group 3 than group 1 (P < 0.016). In ADP-stimulated platelets, expression markers for all glycoproteins were significantly higher in all groups.

CONCLUSION

Neither one MAC desflurane nor sevoflurane showed any significant change in ADP-stimulated platelets compared with the control group.

Isoflurane Prevents Platelets from Enhancing Neutrophil-Induced Coronary Endothelial Dysfunction

We evaluated whether platelets can enhance polymorphonuclear neutrophil-induced coronary endothelial dysfunction, and, after observing this, whether isoflurane can prevent the effect. Neutrophils, coronary artery segments, and platelets were obtained from 25 healthy dogs. Coronary artery rings were exposed to neutrophils activated with platelet-activating factor (1.0 microM), and after washing and preconstriction with U46619, were evaluated for concentration-related responses to acetylcholine, an endothelium-dependent vasorelaxing drug. Superoxide production by activated neutrophils was measured spectrophotometrically. Adherence of the activated neutrophils to the endothelium of coronary segments was assessed by direct counting of neutrophils labeled with fluorescent dye. Measurements were performed in absence and presence of isoflurane (1 minimum alveolar concentration) both with and without platelets. The presence of platelets enhanced the neutrophil-induced rightward shift in the concentration-vasorelaxation response curve to acetylcholine (the concentration of acetylcholine required to elicit 50% of maximal relaxation (-log M) was increased from 6.78 +/- 0.7 to 5.26 +/- 0.6), and it increased superoxide oxide production from 45.0 +/- 4.2 to 54.3 +/- 4.2 nM O2-/5 x 10(6) neutrophils and adherence of activated neutrophils from 204 +/- 10 to 268 +/- 5 neutrophils/mm2. Isoflurane abolished these effects of platelets. In conclusion, platelets enhanced the ability of neutrophils to cause coronary endothelial dysfunction. This effect was prevented by isoflurane. This may be attributable to an inhibitory action on superoxide production by the neutrophils leading to reduced expression of endothelial adhesion molecules and, in turn, reduced neutrophil adherence.

Effects of different anaesthetic agents on immune cell function in vitro

BACKGROUND AND OBJECTIVE

Anaesthesia may affect the regulatory balance of postoperative immune response. The aim of this study was to investigate the effects of different volatile and non-volatile anaesthetic agents and particularly of clinically used agent combinations on the proliferation capacity and cytokine production of immune cells.

METHODS

Peripheral blood mononuclear cells from healthy donors were PHA-activated in the presence or absence of various concentrations of thiopental, propofol, fentanyl, sufentanil, sevoflurane, nitrous oxide and combinations of these anaesthetics. Cell proliferation was assessed by tritiated thymidine uptake. Interleukin-2 production and release of the soluble IL-2 receptor were determined by enzyme immunoassays and used as measures of lymphocyte activation.

RESULTS

Thiopental inhibited cell proliferation in a dose dependent manner (P < 0.001) and reduced sIL-2R release (2090-970 microg mL(-1); P < 0.05). Propofol reduced sIL-2R release at the high concentration of 10 microg mL(-1) (2220 pg mL(-1) 1780 microg mL(-1); p < 0.05). Fentanyl and sufentanil did not compensate for or enhance the inhibitory effects of thiopental. Nitrous oxide, but not sevoflurane, reduced the proliferation of human peripheral blood mononuclear cells (P < 0.05). In combinations with thiopental or nitrous oxide, sevoflurane compensated the inhibitory effects of these two agents. Fentanyl, sufentanil, sevoflurane and nitrous oxide did not affect PHA-induced IL-2 and sIL-2 receptor release by human peripheral blood mononuclear cells.

CONCLUSION

Thiopental and nitrous oxide have immunosuppressive activity. In contrast, sevoflurane may have a beneficial effect by alleviating the immunosuppressive effects of both substances.

Sevoflurane anesthesia attenuates adenosine diphosphate-induced P-selectin expression and platelet-leukocyte conjugate formation

The expression of P-selectin on the surface of platelets and platelet-leukocyte conjugate formation are considered to be an indicator of platelet activation and are important in thrombotic and inflammatory disease. Previous studies have reported the inhibitory effects of sevoflurane on platelet aggregation. We investigated whether sevoflurane alters the expression of P-selectin on platelets and the formation of platelet-leukocyte conjugates. Twenty-five patients undergoing minor extremity surgery received sevoflurane-based general anesthesia, with mask induction and laryngeal mask airway anesthesia maintenance. Whole blood was obtained before and 40 min after sevoflurane anesthesia. Unstimulated and adenosine diphosphate-stimulated samples of whole blood and platelet rich plasma were stained with fluorochrome-conjugated antibodies. The expression of P-selectin on platelets and the formation of platelet-leukocyte conjugates were measured using flow cytometry. Sevoflurane inhibited platelet P-selectin expression. It also reduced the formation of platelet-leukocyte conjugates, both in unstimulated and adenosine diphosphate-stimulated blood samples at 3%-4% end-expiratory sevoflurane concentrations used to maintain anesthesia.

Cardioprotective effects of desflurane: effect of timing and duration of administration in rat myocardium

BACKGROUND

We compared the cardioprotective effects of 1 minimum alveolar concentration (MAC) desflurane administered before, during or after ischaemia, or throughout the experiment (before, during and after ischaemia) on myocardial infarct size following 30 min occlusion of the left anterior descending coronary artery and 3 h reperfusion in adult rats.

METHODS

Fifty male Sprague-Dawley rats were anaesthetized with pentobarbital, intubated and mechanically ventilated. Blood gases, pH and body temperature (37.5-38 degrees C) were controlled. Heart rate and arterial pressure were measured continuously. Animals were randomly assigned to the following groups (n=10 in each group): pentobarbital only ("Pento"); 15 min desflurane administration followed by 10 min of washout before 30 min ischaemia and 3 h reperfusion ("Precond"); 30 min desflurane administration during ischaemia period ('Isch'); desflurane administration during the 15 first min of reperfusion ("Reperf") and desflurane administration throughout the experiment (before, during and after ischaemia; "Long"). Volumes at risk and infarct sizes were assessed by Indian ink and with 2,3,5-triphenyltetrazolium chloride staining, respectively.

RESULTS

Physiological parameters and volumes at risk were not significantly different between groups. In the Pento group, mean myocardial infarct size was 65 (sd 15)% of the volume at risk; myocardial infarct size was reduced to a significant and comparable extent in the desflurane-treated groups (Precond 42 (14)%; Isch 34 (11)%; Reperf 41 (15)%; Long 33 (10)%; P<0.0002 vs Pento group).

CONCLUSIONS

In rats, desflurane 1 MAC significantly decreased myocardial infarct size whatever the period and duration of administration.