Cardioprotective effect of sevoflurane in patients with coronary artery disease undergoing vascular surgery

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.

Comparing cardiac troponin levels using sevoflurane and isoflurane in patients undergoing cardiac surgery: a systematic review and meta-analysis

Introduction: Cardiac troponin is one of the heart biomarkers and its high levels correlates with a high risk of cardiomyocytes damage. This study aimed to compare sevoflurane and isoflurane effect on troponin levels in patients undergoing cardiac surgery.

Methods: We systematically searched for RCTs which had been published in Cochrane library, PubMed, Web of science, CRD, Scopus, and Google Scholar by the end of February 30th, 2019. The quality of articles was evaluated with the Cochrane checklist. GRADE was used for quality of evidence for this meta-analysis. Meta-analysis was done based on random or fixed effect model.

Results: Five studies with total of 190 (sevoflurane) and 191 (isoflurane) patients were included. The results showed that pooled mean difference of troponin levels between the two groups was significant at ICU admission time and 24 hours after entering. The comparison of troponin level changes between the two groups (baseline = at time ICU) in 24 and 48 hours after ICU admission was significant.

Conclusion: This meta-analysis showed that blood troponin levels were significantly lower at the time of arrival in ICU with isoflurane and after 24 hours with sevoflurane. Generally, given the small mean difference between isoflurane and sevoflurane, it seems that none of the medications has a negative effect on the cardiac troponin level.

Anesthetic Agents and Cardiovascular Outcomes of Noncardiac Surgery after Coronary Stent Insertion

Patients undergoing noncardiac surgery after coronary stent implantation are at an increased risk of thrombotic complications. Volatile anesthetics are reported to have organ-protective effects against ischemic injury. Propofol has an anti-inflammatory action that can mitigate ischemia-reperfusion injury. However, the association between anesthetic agents and the risk of major adverse cardiovascular and cerebral event (MACCE) has never been studied before. In the present study, a total of 1630 cases were reviewed. Four different propensity score matchings were performed to minimize selection bias (propofol-based total intravenous anesthesia (TIVA) vs. volatile anesthetics; TIVA vs. sevoflurane; TIVA vs. desflurane; and sevoflurane vs. desflurane). The incidence of MACCE in these four propensity score-matched cohorts was compared. As a sensitivity analysis, a multivariable logistic regression analysis was performed to identify independent predictors for MACCE during the postoperative 30 days both in total and matched cohorts (TIVA vs. volatile agent). MACCE occurred in 6.0% of the patients. Before matching, there was a significant difference in the incidence of MACCE between TIVA and sevoflurane groups (TIVA 5.1% vs. sevoflurane 8.2%, p = 0.006). After matching, there was no significant difference in the incidence of MACCE between the groups of any pairs (TIVA 6.5% vs. sevoflurane 7.7%; p = 0.507). The multivariable logistic regression analysis revealed no significant association of the volatile agent with MACCE (odds ratio 1.48, 95% confidence interval 0.92–2.37, p = 0.104). In conclusion, the choice of anesthetic agent for noncardiac surgery did not significantly affect the development of MACCE in patients with previous coronary stent implantation. However, further randomized trials are needed to confirm our results.

Comparison of effects of propofol versus sevoflurane for patients undergoing cardiopulmonary bypass cardiac surgery

Objective

To compare the effects of propofol versus sevoflurane on the outcomes of patients undergoing cardiac surgery with cardiopulmonary bypass (CPB).

Methods

A total of 110 patients undergoing cardiac surgery with CPB in our hospital from January 2015 to June 2017 were randomly divided into 2 groups (n=55): Group A, in which anesthesia was maintained with sevoflurane, and Group B, in which anesthesia was maintained with propofol. The MMSE score before and after operation, perioperative laboratory index, incidence of postoperative cognitive dysfunction (POCD) and incidence of adverse events between the two groups were compared.

Results

The MMSE score was significantly higher in Group B than in Group A after anesthesia (p<0.05). Serum levels of the brain injury markers neuron-specific enolase, S100β and matrix metalloproteinase 9 were significantly lower in Group B than in Group A (p<0.05). POCD incidence at 12 hour and 24 hour after operation was significantly lower in Group B than in Group A (p<0.05). There were no significant differences in the incidence of low cardiac output and thoracotomy bleeding between two groups.

Conclusion

Compared with sevoflurane, the use of propofol during cardiac surgery with CPB can efficiently improve postoperative cognitive function without increasing the risk of adverse reactions.

MMP-9 and MMP-2 regulation in patients undergoing non-oncological and non-vascular elective surgery independent of the use of propofol or sevoflurane

BACKGROUND

There is debate regarding whether inhaled sevoflurane or intravenous propofol used during anesthesia achieves the best outcome. Propofol has been shown to affect expression of matrix metalloproteinases (MMPs). MMPs are enzymes that play a role in extracellular matrix remodeling, with activity balance disturbances during surgery. The goal of this study was to compare MMP-2/9 concentrations, activity, and tissue inhibitors of metalloproteinases (TIMPs) 1/2 concentrations in blood of who had undergone 2 types of anesthesia: based on volatile sevoflurane and intravenous propofol during non-oncological, non-vascular surgery.

METHODS

39 patients were enrolled into analysis, 20 anesthetized with total intravenous anesthesia with propofol (P), 19 with volatile induction/maintenance of anesthesia with sevoflurane (S). Plasma samples collected before and 24 h after surgery were analyzed for MMP-2/9, and TIMP-1/2 concentrations using ELISAs. Additionally, MMP-2/9 activities were assessed by gelatin zymography.

RESULTS

Study revealed increased MMP-9 concentration (ELISA) (P:p = 0.011; S:p = 0.001) and activity (zymography) (P:p = 0.004; S:p = 0.008) in both groups 24 h after surgery. We noticed decreased (both groups) MMP-2 concentration (P:p = 0.044; S:p = 0.027) with MMP-2 activity increase (P:p = 0.002; S:p = 0.006) 24 h after surgery. We observed decreased TIMP-1 plasma concentrations (P:p = 0.002; S:p = 0.000) 24 h after procedures, while TIMP-2 plasma levels remain unchanged (P:p = 0.097; S:p = 0.172). There were no differences between concentration and activity of MMPs and TIMPs in regard to anesthetic used. Meperidine administration correlated with lower MMP-9 activity (R=-0.430; p = 0.006).

CONCLUSIONS

Concluding, neither sevoflurane nor propofol used as anesthetics modulate MMP-2 and MMP-9 concentrations and activities during non-oncological, non-vascular elective surgery. Meperidine seems to decrease MMP-9 activity.

Sevoflurane inhibits cardiac function in pulmonary fibrosis mice through the TLR4 signaling pathway

Pulmonary fibrosis is often concomitant with myocardial injury. We studied sevoflurane's effects on cardiac function and the expression of the TLR4/inducible nitric oxide synthase (iNOS) signaling pathway on a pulmonary fibrosis model. C57BL/6J wild-type (WT) and TLR4-deficient (TLR4^-/-) mice were randomly divided into a control group and a pulmonary fibrosis group. The model of pulmonary fibrosis was induced by treatment with paraquat (PQ; 20 mg/kg). Four weeks after PQ administration, mice were tested for body weight changes, and histopathology and hydroxyproline in lung. Left ventricular function in each group of mice was measured by echocardiogram before and after sevoflurane inhalation. The expression of TLR4 and iNOS protein were analyzed. Pulmonary fibrosis mice were fed lenalidomide (50 mg/kg/day) for three days and cardiac function was assessed before and after sevoflurane inhalation. WT pulmonary fibrosis mice showed pathological damage and excessive deposition of collagen in the lung and heart. Left ventricular function decreased after four weeks of PQ exposure. TLR4^-/- mice were resistant to pulmonary fibrosis like pathological damage and the effect of sevoflurane on heart rate and ejection fraction than that of WT mice. TLR4 and iNOS expression in WT pulmonary fibrosis mice increased significantly after sevoflurane inhalation. Lenalidomide treatment alleviated the effect of sevoflurane on heart rate and ejection fraction in WT pulmonary fibrosis mice. Sevoflurane inhibits cardiac function in pulmonary fibrosis mice through the TLR4/iNOS pathway. Lenalidomide attenuated the sevoflurane's effect on the cardiac function of mice with pulmonary fibrosis.

Myocardial ischaemia reperfusion injury: the challenge of translating ischaemic and anaesthetic protection from animal models to humans

Myocardial ischaemia reperfusion injury is the leading cause of death in patients with cardiovascular disease. Interventions such as ischaemic pre and postconditioning protect against myocardial ischaemia reperfusion injury. Certain anaesthesia drugs and opioids can produce the same effects, which led to an initial flurry of excitement given the extensive use of these drugs in surgery. The underlying mechanisms have since been extensively studied in experimental animal models but attempts to translate these findings to clinical settings have resulted in contradictory results. There are a number of reasons for this such as dose response, the intensity of the ischaemic stimulus applied, the duration of ischaemia and lost or diminished cardioprotection in common co-morbidities such as diabetes and senescence. This review focuses on current knowledge regarding myocardial ischaemia reperfusion injury and cardioprotective interventions both in experimental animal studies and in clinical trials.

The mechanisms of cardio-protective effects of desflurane and sevoflurane at the time of reperfusion: anaesthetic post-conditioning potentially translatable to humans?

Myocardial conditioning is actually an essential strategy in the management of ischaemia-reperfusion injury. The concept of anaesthetic post-conditioning is intriguing, its action occurring at a pivotal moment (that of reperfusion when ischaemia reperfusion lesions are initiated) where the activation of these cardio-protective mechanisms could overpower the mechanisms leading to ischaemia reperfusion injuries. Desflurane and sevoflurane are volatile anaesthetics frequently used during cardiac surgery. This review focuses on the efficacy of desflurane and sevoflurane administered during early reperfusion as a potential cardio-protective strategy. In the context of experimental studies in animal models and in human atrial tissues in vitro, the mechanisms underlying the cardio-protective effect of these agents and their capacity to induce post-conditioning have been reviewed in detail, underlining the role of reactive oxygen species generation, the activation of the cellular signalling pathways, and the actions on mitochondria along with the translatable actions in humans; this might well be sufficient to set the basis for launching randomized clinical studies, actually needed to confirm this strategy as one of real impact.

The role of Volatile Anesthetics in Cardioprotection: a systematic review

This review evaluates the mechanism of volatile anesthetics as cardioprotective agents in both clinical and laboratory research and furthermore assesses possible cardiac side effects upon usage. Cardiac as well as non-cardiac surgery may evoke perioperative adverse events including: ischemia, diverse arrhythmias and reperfusion injury. As volatile anesthetics have cardiovascular effects that can lead to hypotension, clinicians may choose to administer alternative anesthetics to patients with coronary artery disease, particularly if the patient has severe preoperative ischemia or cardiovascular instability. Increasing preclinical evidence demonstrated that administration of inhaled anesthetics - before and during surgery - reduces the degree of ischemia and reperfusion injury to the heart. Recently, this preclinical data has been implemented clinically, and beneficial effects have been found in some studies of patients undergoing coronary artery bypass graft surgery. Administration of volatile anesthetic gases was protective for patients undergoing cardiac surgery through manipulation of the potassium ATP (K_ATP) channel, mitochondrial permeability transition pore (mPTP), reactive oxygen species (ROS) production, as well as through cytoprotective Akt and extracellular-signal kinases (ERK) pathways. However, as not all studies have demonstrated improved outcomes, the risks for undesirable hemodynamic effects must be weighed against the possible benefits of using volatile anesthetics as a means to provide cardiac protection in patients with coronary artery disease who are undergoing surgery.