Desflurane Versus Propofol in Patients Undergoing Mitral Valve Surgery

Volatile Anesthetic Use Versus Total Intravenous Anesthesia for Patients Undergoing Heart Valve Surgery: A Nationwide Population-Based Study

BACKGROUND

Many studies have suggested that volatile anesthetic use may improve postoperative outcomes after cardiac surgery compared to total intravenous anesthesia (TIVA) owing to its potential cardioprotective effect. However, the results were inconclusive, and few studies have included patients undergoing heart valve surgery.

METHODS

This nationwide population-based study included all adult patients who underwent heart valve surgery between 2010 and 2019 in Korea based on data from a health insurance claim database. Patients were divided based on the use of volatile anesthetics: the volatile anesthetics or TIVA groups. After stabilized inverse probability of treatment weighting (IPTW), the association between the use of volatile anesthetics and the risk of cumulative 1-year all-cause mortality (the primary outcome) and cumulative long-term (beyond 1 year) mortality were assessed using Cox regression analysis.

RESULTS

Of the 30,755 patients included in this study, the overall incidence of 1-year mortality was 8.5%. After stabilized IPTW, the risk of cumulative 1-year mortality did not differ in the volatile anesthetics group compared to the TIVA group (hazard ratio, 0.98; 95% confidence interval, 0.90-1.07; P = .602), nor did the risk of cumulative long-term mortality (hazard ratio, 0.98; 95% confidence interval, 0.93-1.04; P = .579) at a median (interquartile range) follow-up duration of 4.8 (2.6-7.6) years.

CONCLUSIONS

Compared with TIVA, volatile anesthetic use was not associated with reduced postoperative mortality risk in patients undergoing heart valve surgery. Our findings indicate that the use of volatile anesthetics does not have a significant impact on mortality after heart valve surgery. Therefore, the choice of anesthesia type can be based on the anesthesiologists' or institutional preference and experience.

Myocardial Protection by Desflurane: From Basic Mechanisms to Clinical Applications

ABSTRACT

Coronary heart disease is an affliction that is common and has an adverse effect on patients' quality of life and survival while also raising the risk of intraoperative anesthesia. Mitochondria are the organelles most closely associated with the pathogenesis, development, and prognosis of coronary heart disease. Ion abnormalities, an acidic environment, the production of reactive oxygen species, and other changes during abnormal myocardial metabolism cause the opening of mitochondrial permeability transition pores, which disrupts electron transport, impairs mitochondrial function, and even causes cell death. Differences in reliability and cost-effectiveness between desflurane and other volatile anesthetics are minor, but desflurane has shown better myocardial protective benefits in the surgical management of patients with coronary artery disease. The results of myocardial protection by desflurane are briefly summarized in this review, and biological functions of the mitochondrial permeability transition pore, mitochondrial electron transport chain, reactive oxygen species, adenosine triphosphate-dependent potassium channels, G protein-coupled receptors, and protein kinase C are discussed in relation to the protective mechanism of desflurane. This article also discusses the effects of desflurane on patient hemodynamics, myocardial function, and postoperative parameters during coronary artery bypass grafting. Although there are limited and insufficient clinical investigations, they do highlight the possible advantages of desflurane and offer additional suggestions for patients.

Newer Volatile Anesthetic Agents in Cardiac Anesthesia: Review of Literature

Myocardial protection with volatile anesthetic agents have been suggested by multiple studies. These studies, however, are scattered and are often limited to a particular aspect of cardiac anesthesia. Older inhalational agents like halothane is known to cause significant hepatic damage in patients undergoing long duration surgeries while isoflurane is known to have marked vasodilating properties that also affects the coronary arteries leading to coronary “steal” phenomenon. Additionally, newer agents, like sevoflurane and desflurane, have shown more prominent cardioprotective effects than older agents. We searched ScholarOne, Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library. The medical subject headings (MeSH) terms “anaesthesia, inhalational,” “anaesthesia, intravenous, or TIVA,” and “Cardiac anaesthesia or Cardiac Surgery” were used. Additional studies were identified by review of the reference sections of all eligible studies. The aim of this review article is to bring together the evidences with newer inhalational agents and provide a holistic view of their benefits and shortcomings in cardiac anesthesia.

A Trial of Two Anesthetic Regimes for Minimally Invasive Mitral Valve Repair

OBJECTIVE

Minimally invasive mitral valve repair may be associated with prolonged cardioplegic arrest times and ischemic reperfusion injury. Intravenous (propofol) and volatile (sevoflurane) anesthesia are used routinely during cardiac surgery and are thought to provide cardioprotection; however, the individual contribution of each regimen to cardioprotection is unknown. Therefore, the authors sought to compare the cardioprotective effects of propofol and sevoflurane anesthesia in patients undergoing minimally invasive mitral valve repair.

DESIGN

A single-center single-blind randomized controlled trial.

SETTING

A specialized regional cardiac surgery center in Italy.

PARTICIPANTS

The study enrolled 62 adults undergoing elective isolated minimally invasive mitral valve repair for degenerative disease. Exclusion criteria included secondary mitral regurgitation, previously treated coronary artery disease, diabetes mellitus, chronic renal failure requiring dialysis, atrial fibrillation, and documented allergy to either propofol or sevoflurane.

INTERVENTIONS

All patients received video-assisted minimally invasive right minithoracotomy. Patients were randomized to receive propofol or sevoflurane anesthesia in a 1:1 ratio.

MEASUREMENTS AND MAIN RESULTS

Cardiac troponin I release was measured over the first 72 hours postoperatively. Operative, cross-clamp, and total bypass times were similar between groups. Cardiac troponin I release was reduced nonsignificantly in the propofol group (p = 0.62), and peak troponin I release was correlated with cross-clamp time in both groups. There were no differences in terms of intraoperative lactate release and blood pH between groups.

CONCLUSION

Propofol and sevoflurane anesthesia were associated with similar degrees of myocardial injury, indicating comparable cardioprotection. Myocardial injury was related directly to the duration of cardioplegic arrest.

Comparison of the effects of inhalational anesthesia with desflurane and total intravenous anesthesia on cardiac biomarkers after aortic valve replacement

Objective (s):

The aim of this study was to compare the effects of using inhalational anesthesia with desflurane with that of a total intravenous (iv) anesthetic technique using midazolam-fentanyl-propofol on the release of cardiac biomarkers after aortic valve replacement (AVR) for aortic stenosis (AS). The specific objectives included (a) determination of the levels of ischemia-modified albumin (IMA) and cardiac troponin I (cTnI) as markers of myocardial injury, (b) effect on mortality, morbidity, duration of mechanical ventilation, length of Intensive Care Unit (ICU) and hospital stay, incidence of arrhythmias, pacing, cardioversion, urine output, and serum creatinine.

Methodology and Design:

Prospective randomized clinical study.

Setting:

Operation room of a cardiac surgery center of a tertiary teaching hospital.

Participants:

Seventy-six patients in New York Heart Association classification II to III presenting electively for AVR for severe symptomatic AS.

Interventions:

Patients included in the study were randomized into two groups and subjected to either a desflurane-fentanyl based technique or total IV anesthesia (TIVA). Blood samples were drawn at preordained intervals to determine the levels of IMA, cTnI, and serum creatinine.

Measurements and Main Results:

The IMA and cTnI levels were not found to be significantly different between both the study groups. Patients in the desflurane group were found to had significantly lower ICU and hospital stays and duration of postoperative mechanical ventilation as compared to those in the TIVA group. There was no difference found in mean heart rate, urine output, serum creatinine, incidence of arrhythmias, need for cardioversion, and 30-day mortality between both groups. The patients in the TIVA group had higher mean arterial pressures on weaning off cardiopulmonary bypass as well as postoperatively in the ICU and recorded lower inotrope usage.

Conclusion:

The result of our study remains ambiguous regarding the overall protective effect of desflurane in patients undergoing AVR although some benefit in terms of shorter duration of postoperative mechanical ventilation, ICU and hospital stays, as well as cTnI, were seen. However, no difference in overall outcome could be clearly established between patients who received desflurane and those that were managed solely with IV anesthetic technique using propofol.

Additive Effect on Survival of Anaesthetic Cardiac Protection and Remote Ischemic Preconditioning in Cardiac Surgery: A Bayesian Network Meta-Analysis of Randomized Trials

INTRODUCTION

Cardioprotective properties of volatile agents and of remote ischemic preconditioning have survival effects in patients undergoing cardiac surgery. We performed a Bayesian network meta-analysis to confirm the beneficial effects of these strategies on survival in cardiac surgery, to evaluate which is the best strategy and if these strategies have additive or competitive effects.

METHODS

Pertinent studies were independently searched in BioMedCentral, MEDLINE/PubMed, Embase, and the Cochrane Central Register (updated November 2013). A Bayesian network meta-analysis was performed. Four groups of patients were compared: total intravenous anesthesia (with or without remote ischemic preconditioning) and an anesthesia plan including volatile agents (with or without remote ischemic preconditioning). Mortality was the main investigated outcome.

RESULTS

We identified 55 randomized trials published between 1991 and 2013 and including 6,921 patients undergoing cardiac surgery. The use of volatile agents (posterior mean of odds ratio = 0.50, 95% CrI 0.28-0.91) and the combination of volatile agents with remote preconditioning (posterior mean of odds ratio = 0.15, 95% CrI 0.04-0.55) were associated with a reduction in mortality when compared to total intravenous anesthesia. Posterior distribution of the probability of each treatment to be the best one, showed that the association of volatile anesthetic and remote ischemic preconditioning is the best treatment to improve short- and long-term survival after cardiac surgery, suggesting an additive effect of these two strategies.

CONCLUSIONS

In patients undergoing cardiac surgery, the use of volatile anesthetics and the combination of volatile agents with remote preconditioning reduce mortality when compared to TIVA and have additive effects. It is necessary to confirm these results with large, multicenter, randomized, double-blinded trials comparing these different strategies in cardiac and non-cardiac surgery, to establish which volatile agent is more protective than the others and how to best apply remote ischemic preconditioning.

Peri-operative anaesthetic myocardial preconditioning and protection - cellular mechanisms and clinical relevance in cardiac anaesthesia

Preconditioning has been shown to reduce myocardial damage caused by ischaemia–reperfusion injury peri-operatively. Volatile anaesthetic agents have the potential to provide myocardial protection by anaesthetic preconditioning and, in addition, they also mediate renal and cerebral protection. A number of proof-of-concept trials have confirmed that the experimental evidence can be translated into clinical practice with regard to postoperative markers of myocardial injury; however, this effect has not been ubiquitous. The clinical trials published to date have also been too small to investigate clinical outcome and mortality. Data from recent meta-analyses in cardiac anaesthesia are also not conclusive regarding intra-operative volatile anaesthesia. These inconclusive clinical results have led to great variability currently in the type of anaesthetic agent used during cardiac surgery. This review summarises experimentally proposed mechanisms of anaesthetic preconditioning, and assesses randomised controlled clinical trials in cardiac anaesthesia that have been aimed at translating experimental results into the clinical setting.

Does pharmacological conditioning with the volatile anaesthetic sevoflurane offer protection in liver surgery?

BACKGROUND

A recently published randomized control trial (RCT) showed a protection of the remnant liver from ischemia-reperfusion (I/R) injury by pharmacological pre-conditioning with a volatile anaesthetic in patients undergoing hepatic resection. Whether the continuous application of volatile anaesthetics (pharmacological conditioning) also protects against I/R injury is unknown.

METHODS

Consecutive patients undergoing liver resection with inflow occlusion from 2005-2007 were included in the trial. Two groups of anaesthesia regimens with either continuous application of the volatile anaesthetic sevoflurane (pharmacological conditioning) or continuous infusion of the intravenous (i.v.) anaesthetic propofol (control group) were compared. Endpoints were serum-peak-aspartate aminotransferase (AST)/ alanine aminotranferease (ALT) levels, length of stay (LOS) and intensive care unit (ICU) stays, and the occurrence of post-operative complications.

RESULTS

Two hundred and twenty-seven patients were included. Pharmacological conditioning did not protect the remnant liver from IR injury (adjusted difference for peak-AST:61.9 U/l, 95% confidence interval (CI): -151.7-275.4 U/l, P = 0.568; peak-ALT:136.1 U/l, 95% CI: -113.7-385.9 U/l, P = 0.284) nor reduce LOS (adjusted difference 0.9 days, 95% CI: -2.6-4.3 days, P = 0.622) or ICU stay (1.6 days, 95% CI: -0.2-3.3 days, P = 0.079), and was not associated with reduced complication rates (adjusted OR 1.12, 95% CI:0.6-2.3, P = 0.761) compared with the control group.

CONCLUSION

In this retrospective study, continuous volatile anaesthesia in liver resection does not provide protection of the remnant liver from IR injury compared with continuous i.v. anaesthesia.

Randomized comparison of sevoflurane versus propofol to reduce perioperative myocardial ischemia in patients undergoing noncardiac surgery

BACKGROUND

Volatile anesthetics provide myocardial preconditioning in coronary surgery patients. We hypothesized that sevoflurane compared with propofol reduces the incidence of myocardial ischemia in patients undergoing major noncardiac surgery.

METHODS AND RESULTS

We enrolled 385 patients at cardiovascular risk in 3 centers. Patients were randomized to maintenance of anesthesia with sevoflurane or propofol. We recorded continuous ECG for 48 hours perioperatively, measured troponin T and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) on postoperative days 1 and 2, and evaluated postoperative delirium by the Confusion Assessment Method. At 6 and 12 months, we contacted patients by telephone to assess major adverse cardiac events. The primary end point was a composite of myocardial ischemia detected by continuous ECG and/or troponin elevation. Additional end points were postoperative NT-proBNP concentrations, major adverse cardiac events, and delirium. Patients and outcome assessors were blinded. We tested dichotomous end points by χ(2) test and NT-proBNP by Mann-Whitney test on an intention-to-treat basis. Myocardial ischemia occurred in 75 patients (40.8%) in the sevoflurane and 81 (40.3%) in the propofol group (relative risk, 1.01; 95% confidence interval, 0.78-1.30). NT-proBNP release did not differ across allocation on postoperative day 1 or 2. Within 12 months, 14 patients (7.6%) suffered a major adverse cardiac event after sevoflurane and 17 (8.5%) after propofol (relative risk, 0.90; 95% confidence interval, 0.44-1.83). The incidence of delirium did not differ (11.4% versus 14.4%; P=0.379).

CONCLUSIONS

Compared with propofol, sevoflurane did not reduce the incidence of myocardial ischemia in high-risk patients undergoing major noncardiac surgery. The sevoflurane and propofol groups did not differ in postoperative NT-proBNP release, major adverse cardiac events at 1 year, or delirium.

Late pharmacologic conditioning with volatile anesthetics after cardiac surgery

INTRODUCTION

The aim of this randomized controlled trial was to investigate whether volatile anesthetics used for postoperative sedation have any beneficial effects on myocardial injury in cardiac surgery patients after on-pump valve replacement.

METHODS

Anesthesia was performed with propofol. After arrival in the intensive care unit (ICU), 117 patients were randomized to be sedated for at least 4 hours with either propofol or sevoflurane. Sevoflurane was administered by using the anesthetic-conserving device. Troponin T, creatine kinase, creatine kinase from heart muscle tissue, myoglobin, and oxygenation index were determined on arrival at the ICU, 4 hours after sedation, and in the morning of the first postoperative day (POD1). Primary end points were cardiac injury markers on POD1. As secondary end points oxygenation, postoperative pulmonary complications, and ICU and hospital stay were documented.

RESULTS

Fifty-six patients were analyzed in the propofol arm, and 46 patients in the sevoflurane arm. Treatment groups were comparable with regard to patient demographics and intraoperative characteristics. Concentration of troponin T as the most sensitive marker for myocardial injury at POD1 was significantly lower in the sevoflurane group compared with the propofol group (unadjusted difference, -0.4; 95% CI, -0.7 to -0.1; P < 0.01; adjusted difference, -0.2; 95% CI, -0.4 to -0.02; P = 0.03, respectively).

CONCLUSIONS

The data presented in this investigation indicate that late postconditioning with the volatile anesthetic sevoflurane might mediate cardiac protection, even with a late, brief, and low-dose application.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00924222.

Sevoflurane vs. propofol in patients with coronary disease undergoing mitral surgery: a randomised study

BACKGROUND

Myocardial ischemic damage is reduced by volatile anaesthetics in patients undergoing low-risk coronary artery bypass graft surgery; few and discordant results exist in other settings. We therefore performed a randomised controlled trial (sevoflurane vs. propofol) to compare cardiac troponin release in patients with coronary disease undergoing mitral surgery.

METHODS

Patients with coronary artery disease undergoing mitral surgery were randomly allocated to receive either sevoflurane (50 patients) or propofol (50 patients) as main hypnotic. The primary endpoint of the study was peak post-operative cardiac troponin release defined as the maximum value among the post-operative values measured at intensive care unit arrival, 4 h later, on the first and second post-operative day.

RESULTS

There was no significant difference in post-operative peak troponin release, the median (25th-75th percentiles) values being 14.9 (10.1-22.1) ng/ml and 14.5 (8.8-17.6) ng/ml in the sevoflurane and propofol groups, respectively (P = 0.4). Fentanyl administration was different between the two groups: 1347 ± 447 μg in patients receiving sevoflurane and 1670 ± 469 μg in those receiving propofol, P = 0.002. The 1-year follow-up identified two patients who died in the propofol group (one myocardial infarction and one low cardiac output syndrome) and one in the sevoflurane group (myocardial infarction).

CONCLUSION

In this study, patients with coronary artery disease undergoing mitral surgery did not benefit from the cardioprotective properties of halogenated anaesthetics. Sevoflurane anaesthesia was not associated to lower cardiac troponin release when compared with propofol anaesthesia.

The mitochondrial permeability transition pore and its role in anaesthesia-triggered cellular protection during ischaemia-reperfusion injury

This review summarises the most recent data in support of the role of the mitochondrial permeability transition pore (mPTP) in ischaemia-reperfusion injury, how anaesthetic agents interact with this molecular channel, and the relevance this holds for current anaesthetic practice. Ischaemia results in damage to the electron transport chain of enzymes and sets into play the assembly of a non-specific mega-channel (the mPTP) that transgresses the inner mitochondrial membrane. During reperfusion, uncontrolled opening of the mPTP causes widespread depolarisation of the inner mitochondrial membrane, hydrolysis of ATP, mitochondrial rupture and eventual necrotic cell death. Similarly, transient opening of the mPTP during less substantial ischaemia leads to differential swelling of the intermembrane space compared to the mitochondrial matrix, rupture of the outer mitochondrial membrane and release of pro-apoptotic factors into the cytosol. Recent data suggests that cellular protection from volatile anaesthetic agents follows specific downstream interactions with this molecular channel that are initiated early during anaesthesia. Intravenous anaesthetic agents also prevent the opening of the mPTP during reperfusion. Although by dissimilar mechanisms, both volatiles and propofol promote cell survival by preventing uncontrolled opening of the mPTP after ischaemia. It is now considered that anaesthetic-induced closure of the mPTP is the underlying effector mechanism that is responsible for the cytoprotection previously demonstrated in clinical studies investigating anaesthetic-mediated cardiac and neuroprotection. Manipulation of mPTP function offers a novel means of preventing ischaemic cell injury. Anaesthetic agents occupy a unique niche in the pharmacological armamentarium available for use in preventing cell death following ischaemia-reperfusion injury.

Clinical application of the cardioprotective effects of volatile anaesthetics: CON--total intravenous anaesthesia or not total intravenous anaesthesia to anaesthetise a cardiac patient?

Although volatile anaesthetics show strong and easily reproducible cardioprotective effects in animal experiments, these effects are less obvious in clinical settings. Indeed, more than a decade after the first human clinical study, the number of publications has increased extensively, but the encouraging results from previous studies in terms of myocardial protection have failed to translate into an improvement in survival or a decrease the incidence of myocardial infarction. No consensus on the modalities of administration of volatile anaesthetics has been agreed and when the experimental protocols are transposed into daily clinical practice, their cardioprotective effects are still weak. The reasons for the disparities between experimental and clinical studies will be reviewed here, especially the role of patients' co-morbidities and medications as well as the limitations of the main positive clinical trials. Recent data showing anti-inflammatory properties of propofol will also be explained. One of the most important clinical benefits of propofol is that it can be used by target-controlled or continuous infusion for anaesthesia and sedation throughout the surgical and critical care periods without the risk of a transition failure. Further large multi-centre clinical investigations are still required.

Volatile agents for cardiac protection in noncardiac surgery: a randomized controlled study

OBJECTIVE

Volatile anesthetics reduce the risk of myocardial infarction and mortality in coronary artery surgery. Recently, the American College of Cardiology/American Heart Association Guidelines suggested the use of volatile anesthetic agents for the maintenance of general anesthesia during noncardiac surgery in patients at risk for perioperative myocardial ischemia, but no randomized experience to document the cardioprotective effects of these agents exists in this setting. Therefore, the authors performed a prospective, randomized, controlled trial to compare the effects of sevoflurane versus total intravenous anesthesia, in terms of postoperative cardiac troponin I release in patients undergoing noncardiac surgery.

DESIGN

A randomized, controlled trial.

SETTING

A teaching hospital.

PARTICIPANTS

Eighty-eight consecutive patients undergoing noncardiac surgery.

INTERVENTIONS

Patients were allocated randomly to receive either volatile anesthetic (44 patients) as the main anesthetic agent or total intravenous anesthesia (TIVA) (44 patients).

MEASUREMENTS

Postoperative cardiac troponin I release was measured as a marker of myocardial necrosis. Patients with detectable postoperative troponin I in the sevoflurane group (12/44, 27.3%) were similar to those in the propofol group (9/44, 20.5%; p = 0.6). There was no significant reduction of postoperative median peak cTnI release (0.16 ± 0.71 ng/mL in the sevoflurane group compared with the TIVA group, 0.03 ± 0.08 ng/mL; p = 0.4). Three patients died at the 1-year follow-up for noncardiac causes (2 in the TIVA group).

CONCLUSIONS

In the authors' experience, patients undergoing noncardiac surgery did not benefit from anesthesia based on halogenated anesthetics. Further studies are necessary to evaluate the cardioprotective effects of volatile agents in noncardiac surgery.

A randomized controlled trial comparing an intraoperative goal-directed strategy with routine clinical practice in patients undergoing peripheral arterial surgery

BACKGROUND AND OBJECTIVE

We hypothesized that, in vascular surgery patients, the application of a goal-directed strategy based on a pulse contour-derived cardiac index would be associated with a better haemodynamic status than the application of routine perioperative care and that the amount of fluid and/or inotropes required in such a goal-directed therapy depended on the general anaesthetic technique used.

METHODS

Patients undergoing peripheral arterial bypass grafting were randomly assigned to three groups. In group 1, haemodynamic management was performed according to routine clinical practice. In the two other groups (groups 2 and 3) a goal-directed therapy was applied aiming to maintain the pulse contour-derived cardiac index above 2.5 l m min. Patients in groups 1 and 2 received sevoflurane-based anaesthesia and patients in group 3 propofol-based anaesthesia. Haemodynamic variables, amount of fluid and administration of inotropes were assessed at different time intervals.

RESULTS

The amount of fluid administered was not significantly different between the groups. Two patients in group 1, 13 patients in group 2 and 12 patients in group 3 were treated with dobutamine (P < 0.001). None of the patients anaesthetized with sevoflurane (groups 1 and 2) experienced postoperative cardiovascular complications, whereas four patients in the total intravenous group (group 3) experienced major postoperative cardiovascular complications (P = 0.005).

CONCLUSION

In the conditions of the present study, the application of a goal-directed therapy aiming to maintain the cardiac index above 2.5 l min m did not result in a higher tissue oxygen delivery than when applying the standard haemodynamic strategy nor did it depend on the anaesthetic technique used.

The anesthesia patient with acute coronary syndrome

This article reviews the current state of knowledge of the pathophysiology, diagnosis, and treatment of acute coronary syndrome outside and during the perioperative period. It highlights some aspects of relevance for the anesthesiologist caring for these patients. Perioperative modalities for the management of patients suffering from this syndrome, the major guidelines and the evidence behind them, and possible avenues for future research is explored.

Drugs mediating myocardial protection

The occurrence of myocardial ischaemia will result in either reversible or irreversible myocardial dysfunction. Even when revascularization is successful, some reperfusion injury may occur that transiently impairs myocardial function. Therefore, treatment should not only be directed towards prompt restoration of myocardial blood flow but measures should also be taken to prevent or alleviate the consequences of myocardial reperfusion injury. Over the years, various strategies have been developed. The present contribution reviews a number of these strategies focusing on pharmacological treatments that have been developed to address myocardial reperfusion injury.

Organ protection by volatile anesthetics in non-coronary artery bypass grafting surgery

The cardioprotective properties of volatile anesthetics have been widely demonstrated by numerous randomized studies and meta-analyses in the setting of cardiac surgery, above of all during coronary artery bypass grafting procedures. Recently, conflicting results have been presented in cardiac non-coronary artery bypass grafting surgery. Unfortunately, despite the existence of a great number of studies comparing a total intravenous anesthetic regimen with an inhalational regimen, at present there are no randomized studies presenting data regarding mortality and important outcomes, such as myocardial infarction, in non-cardiac surgery. In this review we analyze and present the results of the most recent and important studies regarding anesthetic preconditioning in cardiac and in noncardiac surgery. Furthermore, we focus on the emerging data from animal experiments, discussing in particular the molecular mechanisms underlying anesthetic preconditioning.

Update on inhalational anaesthetics

PURPOSE OF REVIEW

Inhalational anaesthetic agents are a cornerstone in modern anaesthetic practice. The currently used compounds are very effective and have a good safety profile. In addition, it has been demonstrated that they possess organ-protective properties that might provide an additional tool in the treatment or prevention of the consequences of organ ischaemia-reperfusion injury or both. The present review summarizes some of the most recent findings on this subject.

RECENT FINDINGS

The mechanisms underlying the organ-protective effects of inhalational anaesthetics continue to be further unravelled. The main challenge, however, is to determine the clinical importance of these protective effects and their potential benefits for patients. Initial observations in cardiac surgery are encouraging, and the first clinical studies on other organ systems are being published. Noble gases share these organ-protective properties and may provide an additional tool for this purpose both in situations in which anaesthesia is needed (xenon) or in cases in which anaesthesia is not necessary (helium).

SUMMARY

In the experimental setting, inhalational anaesthetics have protective effects against ischaemia-reperfusion injury. Initial perioperative data suggest that these effects may also result into clinically relevant improved organ function. However, further research will be needed to reveal whether these organ-protective properties will ultimately translate into an improved short-term and long-term postoperative outcome.

Anaesthesia and myocardial ischaemia/reperfusion injury

Anaesthetists are confronted on a daily basis with patients with coronary artery disease, myocardial ischaemia, or both during the perioperative period. Therefore, prevention and ultimately adequate therapy of perioperative myocardial ischaemia and its consequences are the major challenges in current anaesthetic practice. This review will focus on the translation of the laboratory evidence of anaesthetic-induced cardioprotection into daily clinical practice.

Update on pharmacology of hypnotic drugs

PURPOSE OF REVIEW

This review is intended to provide an update on pharmacology of hypnotic drugs and current state of published research for new or improved agents.

RECENT FINDINGS

Albeit no completely new drugs have been launched in the last few years, research on pharmacology of existing drugs is still ongoing, and new formulations of existing drugs are proposed (propofol, isoflurane). Xenon, an old but so far unavailable drug, has elicited new interests and this review will examine the recent publications on this fascinating agent.

SUMMARY

These results will improve our handling of existing drugs and open new perspectives on drug monitoring through measurement of propofol concentrations in expired air.