The volatile anesthetic sevoflurane inhibits activation of neutrophil granulocytes during simulated extracorporeal circulation

Glibenclamide Serves as a Potent Vasopressor to Treat Vasoplegia After Cardiopulmonary Bypass and Reperfusion in a Porcine Model

The hemodynamic stabilization of patients after complex cardiac surgery is a daily challenge. The use of high doses of catecholamines is common but has potential adverse effects. Glibenclamide, a KATP blocker, seems to attenuate vasoplegia in different animal models of septic shock. Therefore, the aim of this study was to investigate the impact of Glibenclamide on the vasoplegic syndrome after cardiopulmonary bypass in a porcine model. In this experimental study, 20 landrace pigs were randomized into two groups and examined: In the control group, standard medical therapy, including norepinephrine, was used, and in the study group standard medical therapy plus additional Glibenclamide was administered. Following general anesthesia, prolonged cardiopulmonary bypass and aortic cross-clamping was performed. In the study group, Glibenclamide was administered 45 min after weaning from cardiopulmonary bypass. The dosage used was 10 mg/kg as a bolus, followed by a continuous infusion of 10 mg/kg/h. Hemodynamic and laboratory measurements were performed. Glibenclamide had a relevant effect on circulatory parameters. With increasing vascular resistance and blood pressure, norepinephrine was able to be reduced. While the heart rate dropped to physiological levels, the cardiac index decreased as well. The results lead to the conclusion that Glibenclamide was able to break through vasoplegic syndrome and could therefore serve as a potent drug to stabilize patients after cardiac surgery.

The Anti-Inflammatory and Antioxidant Effects of Propofol and Sevoflurane in Children With Cyanotic Congenital Heart Disease

OBJECTIVE

The authors aimed to compare the anti-inflammatory and antioxidant effects of propofol and sevoflurane in children with cyanotic congenital heart disease (CCHD) undergoing cardiac surgery with cardiopulmonary bypass.

DESIGN

Prospective, randomized, double-blind study.

SETTING

Single center, university hospital.

PARTICIPANTS

Children ages 1-10 years with CCHD undergoing elective cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

Children were randomized to receive general anesthesia with either sevoflurane (group S) or propofol (group P). Systemic inflammatory response syndrome (SIRS) occurrence was assessed at the end of the surgery and at the sixth, 12th, and 24th postoperative hours. Blood samples were obtained at 4 times: after anesthesia induction (T0), after release of the aortic cross-clamp (T1), at the end of the surgery (T2), and at the postoperative 24th hour (T3). The serum levels of interleukin 6 and tumor necrosis factor alpha, and the total antioxidant status (TAS) and total oxidant status, were analyzed.

RESULTS

SIRS was more common in group S than in group P at all times (p = 0.020, p = 0.036, p = 0.004, p = 0.008). There were no significant differences between the groups in the mean tumor necrosis factor alpha and interleukin 6 levels at any time. The TAS level at T2 was higher in group P than group S (p = 0.036). The serum TAS level increased at T2 compared with T0 in group P, but it decreased in group S (p = 0.041).

CONCLUSION

The results showed that propofol provided a greater antioxidant effect and reduced SIRS postoperatively more than sevoflurane in children with CCHD undergoing cardiac surgery.

Effect of sevoflurane on the inflammatory response during cardiopulmonary bypass in cardiac surgery: the study protocol for a randomized controlled trial

Background

Recent experimental evidence shows that sevoflurane can reduce the inflammatory response during cardiac surgery with cardiopulmonary bypass. However, this observation so far has not been assessed in an adequately powered randomized controlled trial.

Methods

We plan to include one hundred patients undergoing elective coronary artery bypass graft with cardiopulmonary bypass who will be randomized to receive either volatile anesthetics during cardiopulmonary bypass or total intravenous anesthesia. The primary endpoint of the study is to assess the inflammatory response during cardiopulmonary bypass by measuring PMN-elastase serum levels. Secondary endpoints include serum levels of other pro-inflammatory markers (IL-1β, IL-6, IL-8, TNFα), anti-inflammatory cytokines (TGFβ and IL-10), and microRNA expression in peripheral blood to achieve possible epigenetic mechanisms in this process. In addition clinical endpoints such as presence of major complications in the postoperative period and length of hospital and intensive care unit stay will be assessed.

Discussion

The trial may determine whether adding volatile anesthetic during cardiopulmonary bypass will attenuate the inflammatory response.

Trial registration

ClinicalTrials.gov NCT02672345. Registered on February 2016 and updated on June 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-020-04809-x.

Left ventricular assist device implantation causes platelet dysfunction and proinflammatory platelet-neutrophil interaction

Blood flow through left ventricular assist devices (LVAD) may induce activation and dysfunction of platelets. Dysfunctional platelets cause coagulation disturbances and form platelet-neutrophil conjugates (PNC), which contribute to inflammatory tissue damage. This prospective observational cohort study investigated patients, who underwent implantation of a LVAD (either HeartMate II (HM II) (n = 7) or HeartMate 3 (HM 3) (n = 6)) and as control patients undergoing coronary artery bypass grafting (CABG) and/or aortic valve replacement (AVR) (n = 10). We performed platelet and leukocyte flow cytometry, analysis of platelet activation markers, and platelet aggregometry. Platelet CD42b expression was reduced at baseline and perioperatively in HM II/3 compared to CABG/AVR patients. After surgery the platelet activation marker β-thromboglobulin and platelet microparticles increased in all groups while platelet aggregation decreased. Platelet aggregation was more significantly impaired in LVAD compared to CABG/AVR patients. PNC were higher in HM II compared to HM 3 patients. We conclude that LVAD implantation is associated with platelet dysfunction and proinflammatory platelet-leukocyte binding. These changes are less pronounced in patients treated with the newer generation LVAD HM 3. Future research should identify device-specific LVAD features, which are associated with the least amount of platelet activation to further improve LVAD therapy.

Sevoflurane modulates the release of reactive oxygen species, myeloperoxidase, and elastase in human whole blood: Effects of different stimuli on neutrophil response to volatile anesthetic in vitro

Volatile anesthetics have been shown to modulate polymorphonuclear neutrophil (PMN) functions. The aim of this study was to examine the impact of clinically relevant concentrations of sevoflurane (SEVO), a volatile anesthetic, on the release of reactive oxygen species (ROS), myeloperoxidase (MPO), and elastase (EL) from human activated PMNs. For this purpose, samples of whole blood were collected from healthy volunteers and exposed in vitro to 2.3% or 4.6% SEVO in air. To assess for a stimulus-dependent effect of the volatile anesthetic, PMNs were activated using different validated protocols. Artificial stimulation of neutrophils involved either a combination of cytochalasin B (CB) and N-formyl-methionyl-leucyl-phenylalanine (fMLP) or phorbol 12-myristate 13-acetate (PMA). In addition, a combination of lipopolysaccharide (LPS) and tumor necrosis factor alpha (TNF-α) was also tested as a natural activation mean of PMNs. The production of ROS by PMNs was assessed by L-012 chemiluminescence. Total MPO and EL released in supernatant were measured by enzyme-linked immunosorbent assay (ELISA). Furthermore, degranulation of the active fraction of MPO was also measured by specific immunological extraction followed by enzymatic detection (SIEFED). Overall, SEVO enhanced the release of ROS, MPO, and EL following artificial stimulation of PMNs but the volatile anesthetic inhibited the degranulation of active MPO and EL after neutrophil exposure to LPS and TNF-α. This study highlighted that the effect of SEVO on activated PMNs is dependent on the conditions of cell stimulation. These properties should be taken into consideration in future studies investigating immunomodulatory effects of volatile anesthetics.

Adenosine Receptor Adora2b Plays a Mechanistic Role in the Protective Effect of the Volatile Anesthetic Sevoflurane during Liver Ischemia/Reperfusion

Background

Liver ischemia/reperfusion (IR) injury is characterized by hepatic tissue damage and an inflammatory response. This is accompanied by the formation and vascular sequestration of platelet–neutrophil conjugates (PNCs). Signaling through Adora2b adenosine receptors can provide liver protection. Volatile anesthetics may interact with adenosine receptors. This study investigates potential antiinflammatory effects of the volatile anesthetic sevoflurane during liver IR.

Methods

Experiments were performed ex vivo with human blood and in a liver IR model with wild-type, Adora2a−/−, and Adora2b−/− mice. The effect of sevoflurane on platelet activation, PNC formation and sequestration, cytokine release, and liver damage (alanine aminotransferase release) was analyzed using flow cytometry, luminometry, and immunofluorescence. Adenosine receptor expression in liver tissue was analyzed using immunohistochemistry and real-time polymerase chain reaction.

Results

Ex vivo experiments indicate that sevoflurane inhibits platelet and leukocyte activation (n = 5). During liver IR, sevoflurane (2 Vol%) decreased PNC formation 2.4-fold in wild-type (P < 0.05) but not in Adora2b−/− mice (n ≥ 5). Sevoflurane reduced PNC sequestration 1.9-fold (P < 0.05) and alanine aminotransferase release 3.5-fold (P < 0.05) in wild-type but not in Adora2b−/− mice (n = 5). In Adora2a−/− mice, sevoflurane also inhibited PNC formation and cytokine release. Sevoflurane diminished cytokine release (n ≥ 3) and increased Adora2b transcription and expression in liver tissue of wild-types (n = 4).

Conclusions

Our experiments highlight antiinflammatory and tissue-protective properties of sevoflurane during liver IR and reveal a mechanistic role of Adora2b in sevoflurane-associated effects. The targeted use of sevoflurane not only as an anesthetic but also to prevent IR damage is a promising approach in the treatment of critically ill patients.

Fluid filtration and vascular compliance during cardiopulmonary bypass: effects of two volatile anesthetics

BACKGROUND

As intraoperative fluid accumulation may negatively impact post-operative organ function, strategies minimizing edema generation should be sought for. During general anesthesia, isoflurane in contrast to sevoflurane has been associated with increased fluid extravasation and edema generation. In this study, we tested sevoflurane against isoflurane with focus on vascular compliance and fluid shifts in an experimental cardiopulmonary bypass (CPB) model.

METHODS

Sixteen pigs underwent 120 min of cardiopulmonary bypass with isoflurane or sevoflurane anesthesia. Net fluid balance, plasma volume, serum-electrolytes, serum-albumin, serum-protein, colloid osmotic pressures in plasma and interstitial fluid, hematocrit levels, and total tissue water content were recorded. Intra-abdominal and intracranial pressures were measured directly, and fluid extravasation rates were calculated.

RESULTS

Fluid extravasation rate increased dramatically in both groups during initiation of cardiopulmonary bypass, with no group differences. The animals of the sevoflurane group needed significantly more fluid supplementation to maintain a constant reservoir volume in the CPB circuit during bypass. Plasma volumes prior to bypass were 56.5 ± 7.9 ml/kg (mean ± SD) and 58.7 ± 3.8 ml/kg in the isoflurane group and sevoflurane group, respectively. During bypass, plasma volumes in the isoflurane group decreased about 25%, and remained significantly lowered when compared to the sevoflurane group, where the values remained stable.

CONCLUSIONS

No differences in fluid extravasation rates were observed between sevoflurane and isoflurane. The increased net fluid balance in the sevoflurane group during cardiopulmonary bypass was not associated with edema generation. Plasma volume was retained in the sevoflurane group, in contrast to the isoflurane group.

Alpha lipoic acid attenuates inflammatory response during extracorporeal circulation

Aim

Extracorporeal circulation (ECC) of blood during cardiopulmonary surgery has been shown to stimulate various pro-inflammatory molecules such as cytokines and chemokines. The biochemical oxidation/reduction pathways of a-lipoic acid suggest that it may have antioxidant properties.

Methods

In this study we aimed to evaluate only patients with coronary heart disease and those planned for coronary artery bypass graft operation. Blood samples were obtained from the patients before the operation (P1) and one (P2), four (P3), 24 (P4) and 48 hours (P5) after administration of a-lipoic acid (LA). The patients were divided into two groups, control and LA treatment group. Levels of interleukin-6 (IL-6) and -8 (IL-8), complement 3 (C3) and 4 (C4), anti-streptolysin (ASO), C-reactive protein (CRP) and haptoglobin were assessed in the blood samples.

Results

Cytokine IL-6 and IL-8 levels were significantly higher after surgery. Compared with the control groups, LA significantly decreased IL-6 and IL-8 levels in a time-dependent manner. CRP levels did not show significant variation in the first three time periods. CRP levels were higher after surgery, especially in the later periods. These results demonstrate that CRP formation depends on cytokine release. C3 and C4 levels were significantly higher after surgery than in the pre-operative period. LA treatment decreased C3 and C4 levels. Therefore, LA administration may be useful for the treatment of diseases and processes where excessive cytokine release could cause oxidative damage.

Conclusions

Our findings suggest a possible benefit of using LA during cardiac surgery to reduce cytokine levels.

Volatile anesthetics-induced neuroinflammatory and anti-inflammatory responses

Volatile anesthetics have been the major anesthetics used clinically for more than 150 years. They provide all components of general anesthesia and are easy to be applied and monitored with modern equipment and technology. In addition to having anesthetic property, volatile anesthetics have multiple other effects. Many studies have clearly shown that volatile anesthetics can reduce systemic and local inflammatory responses induced by various stimuli in humans and animals. On the other hand, recent animal studies have shown that volatile anesthetics may induce mild neuroinflammation. These dual effects on inflammation may have significant biological implications and are briefly reviewed here.