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

Therapeutic strategies to ameliorate mitochondrial oxidative stress in ischaemia-reperfusion injury: A narrative review

Mitochondrial reactive oxygen species (mROS) play a crucial physiological role in intracellular signalling. However, high levels of ROS can overwhelm antioxidant defences and lead to detrimental modifications in protein, lipid and DNA structure and function. Ischaemia-reperfusion injury is a multifaceted pathological state characterised by excessive production of mROS. There is a significant clinical need for therapies mitigating mitochondrial oxidative stress. To date, a variety of strategies have been investigated, ranging from enhancing antioxidant reserve capacity to metabolism reduction. While success has been achieved in non-clinical models, no intervention has yet successfully transitioned into routine clinical practice. In this article, we explore the different strategies investigated and discuss the possible reasons for the lack of translation.

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery.

METHODS

A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery.

METHODS

A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline.

STRUCTURE

Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

Effect of Ciprofol on Left Ventricular Myocardial Strain and Myocardial Work in Children Undergoing Cardiac Surgery: A Single-center Double-blind Randomized Noninferiority Study

OBJECTIVE

The current work was designed to compare the effects of ciprofol and propofol on left ventricular systolic function and myocardial work by noninvasive speckle-tracking echocardiography in children undergoing surgical repair of atrial septal or ventricular septal defects.

DESIGN

A single-center double-blind randomized noninferiority study was conducted.

SETTING

The research occurred at a tertiary care center affiliated with Shanghai Jiao Tong University, China.

PARTICIPANTS

One hundred and twelve children aged 1 month to 16 years undergoing atrial septal or ventricular septal defect surgery with cardiopulmonary bypass were included.

INTERVENTIONS

One hundred and twelve children were allocated randomly to receive ciprofol (n = 67) or propofol (n = 45) in a 1.5:1 ratio. Ciprofol or propofol were intravenously infused at loading doses of 0.4 mg/kg or 2.0 mg/kg, respectively, over 30 seconds, depending on the physical condition of each patient. When the bispectral index was maintained between 45 and 55 after induction, transthoracic echocardiography, including apical two-chamber, three-chamber, and four-chamber views, were collected bedside.

MEASUREMENTS AND MAIN RESULTS

Of the 112 patients enrolled, 104 completed the study. Global longitudinal strain in the ciprofol and propofol groups after anesthesia was -17.3% (95% confidence interval [CI] -18.0% to -16.6%) and -17.8% (95% CI -18.7 to -17.0%) in the full analysis set and -17.5% (95% CI -18.2% to -16.9%) and -17.8% (95% CI -18.7% to -17.0%) in the per-protocol set, respectively. The noninferiority margin was set at 2% and confirmed with a lower limit of two-sided 95% CI for the intergroup difference of 1.58% in the full analysis set and 1.34% in the per-protocol set. There were no significant differences between the groups in left ventricular systolic and diastolic function and myocardial work indices. Postoperative vasoactive-inotropic score, NT-proBNP, duration of mechanical ventilation, and the length of stay in the cardiac intensive care unit and hospital were also comparable between the two groups (all p > 0.05).

CONCLUSIONS

Ciprofol did not show different effects on myocardial function and postoperative outcomes from propofol. Further, on the sensitive cardiac systole marker global longitudinal strain, ciprofol demonstrated noninferiority to propofol. Ciprofol might be an alternative solution for cardiac anesthesia in children with congestive heart disease with mild lesion.

Effects of inhalation versus total intravenous anaesthesia on long-term mortality in older patients after noncardiac surgery: a retrospective observational study

BACKGROUND

Whether the anaesthetic agent used influences postoperative mortality in older patients remains unclear. We evaluated the effect of total intravenous anaesthesia (TIVA) vs inhalation anaesthesia on long-term mortality in older patients after noncardiac surgery.

METHODS

We retrospectively analysed 45,879 patients aged ≥60 yr who underwent noncardiac surgery under general anaesthesia (for ≥2 h) between January 2011 and June 2019. They were divided into two groups according to the type of maintenance anaesthetic. The primary outcome was all-cause mortality within 1 yr after surgery. Secondary outcomes included postoperative complications (postoperative pulmonary complications, perioperative adverse cardiovascular events, and acute kidney injury), and 3-yr and 5-yr mortality after surgery. The stabilised inverse probability of treatment weighting method was used to adjust for potential confounders.

RESULTS

Among 45,879 patients, 7273 (15.9%) patients received TIVA and 38,606 (84.1%) patients received inhalation anaesthesia. After adjustment with inverse probability of treatment weighting, there was no association between the type of anaesthetic agent and 1-yr mortality (hazard ratio=0.95; 95% confidence interval [CI] 0.84-1.08). Results for 3-yr and 5-yr mortality were similar. However, inhalation anaesthesia was associated with increased risk of postoperative complications (odds ratio [OR]=1.30; 95% CI 1.22-1.37 for postoperative pulmonary complications, OR=1.34; 95% CI 1.22-1.48 for perioperative adverse cardiovascular events, and OR=2.19; 95% CI 1.88-2.57 for acute kidney injury). In the subgroup analysis, the choice of anaesthetic agent showed differential effects on 1-yr mortality for female patients and emergency surgery.

CONCLUSION

The choice of anaesthetic agent during the intraoperative period was not associated with 1-yr mortality in older patients undergoing noncardiac surgery.

CLINICAL TRIAL REGISTRATION

Clinical Research Information Service of the Republic of Korea (KCT 0006363).

[Anesthesia for aortic valve stenosis : Anesthesiological management of patients with aortic valve stenosis during noncardiac surgery]

Aortic valve stenosis is a common condition that requires an anesthesiologist's in-depth knowledge of the pathophysiology, diagnostics and perioperative features of the disease. A newly diagnosed aortic valve stenosis is often initially identified from the anamnesis (dyspnea, syncope, angina pectoris) or a suspicious auscultation finding during the anesthesiologist's preoperative assessment. Interdisciplinary collaboration is essential to ensure the optimal management of these patients in the perioperative setting. An accurate anamnesis and examination during the preoperative assessment are crucial to select the most suitable anesthetic approach. Additionally, a precise understanding of the hemodynamic peculiarities associated with aortic valve stenosis is necessary. After a short summary of the overall pathophysiology of aortic valve stenosis, this review article focuses on the specific anesthetic considerations, risk factors for complications, and the perioperative management for noncardiac surgery in patients with aortic valve stenosis.

Anesthetic Management of a Patient With Prinzmetal Angina

Prinzmetal angina (PA) is characterized by the development of reversible vasoconstriction of the coronary arteries, transient ischemic electrocardiographic changes in the ST segment, chest pain at rest, and prompt response to nitrates. Spasms of the coronary arteries can be precipitated during the perioperative period by an imbalance of vasodilator and vasoconstrictor factors of smooth muscle cells, which can lead to myocardial ischemia, cardiac arrhythmias, and death. Nevertheless, this is a relatively unrecognized topic, and literature is scarce about it. We present a case report detailing the successful anesthetic management of a patient diagnosed with PA and a documented nitrate allergy, who underwent bilateral ureterorenoscopy.

Pharmacological Cardioprotection against Ischemia Reperfusion Injury-The Search for a Clinical Effective Therapy

Pharmacological conditioning aims to protect the heart from myocardial ischemia-reperfusion injury (IRI). Despite extensive research in this area, today, a significant gap remains between experimental findings and clinical practice. This review provides an update on recent developments in pharmacological conditioning in the experimental setting and summarizes the clinical evidence of these cardioprotective strategies in the perioperative setting. We start describing the crucial cellular processes during ischemia and reperfusion that drive acute IRI through changes in critical compounds (∆G_ATP, Na⁺, Ca²⁺, pH, glycogen, succinate, glucose-6-phosphate, mitoHKII, acylcarnitines, BH₄, and NAD⁺). These compounds all precipitate common end-effector mechanisms of IRI, such as reactive oxygen species (ROS) generation, Ca²⁺ overload, and mitochondrial permeability transition pore opening (mPTP). We further discuss novel promising interventions targeting these processes, with emphasis on cardiomyocytes and the endothelium. The limited translatability from basic research to clinical practice is likely due to the lack of comorbidities, comedications, and peri-operative treatments in preclinical animal models, employing only monotherapy/monointervention, and the use of no-flow (always in preclinical models) versus low-flow ischemia (often in humans). Future research should focus on improved matching between preclinical models and clinical reality, and on aligning multitarget therapy with optimized dosing and timing towards the human condition.

Perioperative strategies to reduce risk of myocardial injury after non-cardiac surgery (MINS): A narrative review

Myocardial injury is a frequent complication of surgical patients after having non-cardiac surgery that is strongly associated with perioperative mortality. While intraoperative anesthesia-related deaths are exceedingly rare, about 1% of patients undergoing non-cardiac surgery die within the first 30 postoperative days. Given the number of surgeries performed annually, death following surgery is the second leading cause of death in the United States. Myocardial injury after non-cardiac surgery (MINS) is defined as an elevation in troponin concentrations within 30 days postoperatively. Although typically asymptomatic, patients with MINS suffer myocardial damage and have a 10% risk of death within 30 days after surgery and excess risks of mortality that persist during the first postoperative year. Many factors for the development of MINS are non-modifiable, such as preexistent coronary artery disease. Preventive measures, systematic approaches to surveillance and treatment standards are still lacking, however many factors are modifiable and should be considered in clinical practice: the importance of hemodynamic control, adequate oxygen supply, metabolic homeostasis, the use of perioperative medications such as statins, anti-thrombotic agents, beta-blockers, or anti-inflammatory agents, as well as some evidence regarding the choice of sedative and analgesic for anesthesia are discussed. Also, as age and complexity in comorbidities of the surgical patient population increase, there is an urgent need to identify patients at risk for MINS and develop prevention and treatment strategies. In this review, we provide an overview of current screening standards and promising preventive options in the perioperative setting and address knowledge gaps requiring further investigation.

Cognitive function and delirium following sevoflurane or propofol anesthesia for valve replacement surgery: A multicenter randomized controlled trial

Cognitive dysfunction is a common postoperative neurological complication in patients undergoing valve replacement surgery. This study aimed to compare the effects of sevoflurane versus propofol-based total intravenous anesthesia on the incidence of cognitive dysfunction following valve replacement surgery. This multicenter, randomized, controlled double-blinded study was conducted in three teaching hospitals in China. Patients receiving on-pump valve replacement surgery were enrolled. Stratified block randomization was used to randomly assign patients 1:1 to receive sevoflurane (1.0-1.5 MAC) or propofol (2.0-3.0 mg/kg/h) for anesthesia maintenance. The primary outcome was the incidence of cognitive dysfunction assessed by four cognitive tests before, as well as 7-14 days after surgery. Patients were randomly assigned to receive sevoflurane anesthesia (n = 144) or propofol-based total intravenous anesthesia (n = 145). The incidence of postoperative cognitive dysfunction in the sevoflurane anesthesia group (31.9%) was significantly lower than that in the total intravenous anesthesia group (43.4%; relative risk 0.61, 95% confidence interval [CI]: 0.38-0.97, p = 0.044). There was no difference in the incidence of delirium between patients receiving sevoflurane and total intravenous anesthesia (27.8% [35/144] vs. 25.9% [35/145], 1.10, 95% CI: 0.64 to 1.90, p = 0.736). There was a significant difference in the Katz Index on day 3 after surgery (3 [0.9) vs. 3 (1.0], 0.095, 95% CI: 0.05 to 0.43, p = 0.012). No difference was observed in other outcomes between the two groups. For patients undergoing on-pump valve replacement surgery, sevoflurane anesthesia had a smaller effect on cognitive function and independence in daily life activities compared with propofol anesthesia.

Postoperative delirium in geriatric patients with hip fractures

Postoperative delirium (POD) is a frequent complication in geriatric patients with hip fractures, which is linked to poorer functional recovery, longer hospital stays, and higher short-and long-term mortality. Patients with increased age, preoperative cognitive impairment, comorbidities, perioperative polypharmacy, and delayed surgery are more prone to develop POD after hip fracture surgery. In this narrative review, we outlined the latest findings on postoperative delirium in geriatric patients with hip fractures, focusing on its pathophysiology, diagnosis, prevention, and treatment. Perioperative risk prediction, avoidance of certain medications, and orthogeriatric comprehensive care are all examples of effective interventions. Choices of anesthesia technique may not be associated with a significant difference in the incidence of postoperative delirium in geriatric patients with hip fractures. There are few pharmaceutical measures available for POD treatment. Dexmedetomidine and multimodal analgesia may be effective for managing postoperative delirium, and adverse complications should be considered when using antipsychotics. In conclusion, perioperative risk intervention based on orthogeriatric comprehensive care is the most effective strategy for preventing postoperative delirium in geriatric patients with hip fractures.

Induction of JAK2/STAT3 pathway contributes to protective effects of different therapeutics against myocardial ischemia/reperfusion

Insufficiency in coronary blood supply results in myocardial ischemia and consequently, various clinical syndromes and irreversible injuries. Myocardial damage occurs as a result of two processes during acute myocardial infarction (MI): ischemia and subsequent reperfusion. According to the available evidence, oxidative stress, excessive inflammation reaction, reactive oxygen species (ROS) generation, and apoptosis are crucial players in the pathogenesis of myocardial ischemia/reperfusion (IR) injury. There is emerging evidence that Janus tyrosine kinase 2 (JAK2) signal transducer and activator of the transcription 3 (STAT3) pathway offers cardioprotection against myocardial IR injury. This article reviews therapeutics that exert cardioprotective effects against myocardial IR injury through induction of JAK2/STAT3 pathway.

The Protective Effect of Sevoflurane Conditionings Against Myocardial Ischemia/Reperfusion Injury: A Systematic Review and Meta-Analysis of Preclinical Trials in in-vivo Models

Objective

Myocardial ischemia/reperfusion injury (IRI) is a common and serious complication in clinical practice. Sevoflurane conditionings have been identified to provide a protection against myocardial IRI in animal experiments, but their true clinical benefits remain controversial. Here, we aimed to analyze the preclinical evidences obtained in animal models of myocardial IRI and explore the possible reasons for controversial clinical benefits.

Methods

Our primary outcome was the difference in mean infarct size between the sevoflurane and control groups in animal models of myocardial IRI. After searching the databases of PubMed, Embase, Web of Science, and the Cochrane Library, a systematic review retrieved 37 eligible studies, from which 28 studies controlled comparisons of sevoflurane preconditioning (SPreC) and 40 studies controlled comparisons of sevoflurane postconditioning (SPostC) that were made in a pooled random-effects meta-analysis. In total, this analysis included data from 313 control animals and 536 animals subject to sevoflurane conditionings.

Results

Pooled estimates for primary outcome demonstrated that sevoflurane could significantly reduce the infarct size after myocardial IRI whether preconditioning [weighted mean difference (WMD): −18.56, 95% CI: −23.27 to −13.85, P < 0.01; I² = 94.1%, P < 0.01] or postconditioning (WMD: −18.35, 95% CI: −20.88 to −15.83, P < 0.01; I² = 90.5%, P < 0.01) was performed. Interestingly, there was significant heterogeneity in effect size that could not be explained by any of the prespecified variables by meta-regression and stratified analysis. However, sensitivity analysis still identified the cardioprotective benefits of sevoflurane conditionings with robust results.

Conclusion

Sevoflurane conditionings can significantly reduce infarct size in in-vivo models of myocardial IRI. Given the fact that there is a lack of consistency in the quality and design of included studies, more well-performed in-vivo studies with the detailed characterization of sevoflurane protocols, especially studies in larger animals regarding cardioprotection effects of sevoflurane, are still required.

Diagnosis and Management of Patients With Myocardial Injury After Noncardiac Surgery: A Scientific Statement From the American Heart Association

Myocardial injury after noncardiac surgery is defined by elevated postoperative cardiac troponin concentrations that exceed the 99th percentile of the upper reference limit of the assay and are attributable to a presumed ischemic mechanism, with or without concomitant symptoms or signs. Myocardial injury after noncardiac surgery occurs in ≈20% of patients who have major inpatient surgery, and most are asymptomatic. Myocardial injury after noncardiac surgery is independently and strongly associated with both short-term and long-term mortality, even in the absence of clinical symptoms, electrocardiographic changes, or imaging evidence of myocardial ischemia consistent with myocardial infarction. Consequently, surveillance of myocardial injury after noncardiac surgery is warranted in patients at high risk for perioperative cardiovascular complications. This scientific statement provides diagnostic criteria and reviews the epidemiology, pathophysiology, and prognosis of myocardial injury after noncardiac surgery. This scientific statement also presents surveillance strategies and treatment approaches.

Association between tissue oxygenation and myocardial injury in patients undergoing major spine surgery: a prospective cohort study

OBJECTIVE

To describe the association between intraoperative tissue oxygenation and postoperative troponin elevation in patients undergoing major spine surgery. We hypothesised that a decrease in intraoperative skeletal muscle tissue oxygenation (SmO₂) was associated with the peak postoperative cardiac troponin value.

DESIGN

This is a prospective cohort study.

SETTING

Single-centre, University of California San Francisco Medical Center.

PARTICIPANTS

Seventy adult patients undergoing major elective spine surgery.

PRIMARY AND SECONDARY OUTCOME MEASURES

High-sensitivity troponin T (hsTnT) was measured in plasma preoperatively and on the first and second day after surgery to assess the primary outcome of peak postoperative hsTnT. Secondary outcomes included MINS and intensive care unit (ICU) admission within 30 days. Skeletal cerebral tissue oxygenation and SmO₂ was measured continuously with near-infrared spectroscopy during surgery. The primary exposure variable was time-weighted area under the curve (TW AUC) for SmO₂.

RESULTS

Mean age was 65 (33-85) years and 59% were female. No significant association was found between TW AUC for SmO₂ and peak hsTnT (Spearman's correlation, r_s=0.17, p=0.16). A total of 28 (40%) patients had MINS. ICU admission occurred in 14 (40%) in lower vs 25 (71%) in upper half of patients based on TW AUC for SmO₂, p=0.008.

CONCLUSIONS

Decrease in SmO₂ was not a statistically significant predictor for peak troponin value following major spine surgery but is a potential predictor for other postoperative complications.

TRIAL REGISTRATION NUMBER

NCT03518372.

Sevoflurane-Remifentanil Versus Propofol-Remifentanil Anesthesia During Noncardiac Surgery for Patients with Coronary Artery Disease - A Prospective Study Between 2016 and 2017 at a Single Center

BACKGROUND Volatile anesthesia possesses cardioprotective properties, and it is widely used in patients undergoing coronary artery bypass surgery, but no randomized controlled trials (RCTs) are available on the use of sevoflurane-remifentanil versus propofol-remifentanil anesthesia for patients with coronary artery disease (CAD) during noncardiac surgery. This study was designed to compare the 2 different types of general anesthesia in patients with CAD undergoing noncardiac surgery at a single center. MATERIAL AND METHODS Patients with CAD undergoing noncardiac surgery were enrolled in an RCT conducted between March 2016 and December 2017. The participants were randomized to receive either sevoflurane-remifentanil or propofol-remifentanil anesthesia. The primary endpoint was occurrence of in-hospital cardiovascular events. The secondary endpoints included delirium, postoperative nausea and vomiting (PONV), Intensive Care Unit (ICU) length of stay (LOS), in-hospital morbidity and mortality, and hospital LOS. RESULTS A total of 164 participants completed the study (sevoflurane: 81; propofol: 83). The occurrence of in-hospital cardiovascular events did not differ between the 2 groups (42.6% vs 39.4%, P=0.86). The occurrence of delirium did not differ between the 2 groups after the operation. PONV had a higher frequency after sevoflurane anesthesia at 48 h compared with propofol. In-hospital morbidity and mortality, ICU LOS, and hospital LOS were similar between the 2 groups (all P>0.05). At 30 days after surgery, no between-group differences in cardiac morbidity and mortality were observed. CONCLUSIONS In this study, anesthesia using sevoflurane-remifentanil did not provide additional postoperative cardioprotection in comparison with propofol-remifentanil in patients with CAD undergoing noncardiac surgery.

Heterogeneous impact of hypotension on organ perfusion and outcomes: a narrative review

Arterial blood pressure is the driving force for organ perfusion. Although hypotension is common in acute care, there is a lack of accepted criteria for its definition. Most practitioners regard hypotension as undesirable even in situations that pose no immediate threat to life, but hypotension does not always lead to unfavourable outcomes based on experience and evidence. Thus efforts are needed to better understand the causes, consequences, and treatments of hypotension. This narrative review focuses on the heterogeneous underlying pathophysiological bases of hypotension and their impact on organ perfusion and patient outcomes. We propose the iso-pressure curve with hypotension and hypertension zones as a way to visualize changes in blood pressure. We also propose a haemodynamic pyramid and a pressure-output-resistance triangle to facilitate understanding of why hypotension can have different pathophysiological mechanisms and end-organ effects. We emphasise that hypotension does not always lead to organ hypoperfusion; to the contrary, hypotension may preserve or even increase organ perfusion depending on the relative changes in perfusion pressure and regional vascular resistance and the status of blood pressure autoregulation. Evidence from RCTs does not support the notion that a higher arterial blood pressure target always leads to improved outcomes. Management of blood pressure is not about maintaining a prespecified value, but rather involves ensuring organ perfusion without undue stress on the cardiovascular system.

Perioperative pharmacotherapy to prevent cardiac complications in patients undergoing noncardiac surgery

Introduction: Despite advances in surgical and anesthetic techniques, perioperative cardiovascular complications are a major cause of 30-day perioperative mortality. Major cardiovascular complications after noncardiac surgery include myocardial ischemia, congestive heart failure, arrhythmias, and cardiac arrest. Along with surgical risk assessment, perioperative medical optimization can reduce the rates and clinical impact of these complications.Areas Covered: In this review, the authors discuss the pharmacological basis, existing evidence, and professional society recommendations for drug management in preventing cardiovascular complications in patients undergoing noncardiac surgery.Expert opinion: Perioperative management of cardiovascular disease is an increasingly important and growing area of clinical practice. Societal guidelines regarding the use of most routine cardiovascular medications are based on a number of large clinical studies and provide a basic foundation to guide management. However, the heterogeneous nature of patients, as well as surgeries, makes it practically impossible to devise a 'one size fits all' recommendation in this setting. Thus, the importance of a more individualized approach to perioperative risk stratification and management is being increasingly recognized. The underlying comorbidities and cardiac profile as well as the risk of cardiac complications associated with the planned surgery must be factored in to understand the nuance of the management strategies.

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.

Pharmacological Conditioning of the Heart: An Update on Experimental Developments and Clinical Implications

The aim of pharmacological conditioning is to protect the heart against myocardial ischemia-reperfusion (I/R) injury and its consequences. There is extensive literature that reports a multitude of different cardioprotective signaling molecules and mechanisms in diverse experimental protocols. Several pharmacological agents have been evaluated in terms of myocardial I/R injury. While results from experimental studies are immensely encouraging, translation into the clinical setting remains unsatisfactory. This narrative review wants to focus on two aspects: (1) give a comprehensive update on new developments of pharmacological conditioning in the experimental setting concentrating on recent literature of the last two years and (2) briefly summarize clinical evidence of these cardioprotective substances in the perioperative setting highlighting their clinical implications. By directly opposing each pharmacological agent regarding its recent experimental knowledge and most important available clinical data, a clear overview is given demonstrating the remaining gap between basic research and clinical practice. Finally, future perspectives are given on how we might overcome the limited translatability in the field of pharmacological conditioning.

Sevoflurane Alleviates Myocardial Ischemia Reperfusion Injury by Inhibiting P2X7-NLRP3 Mediated Pyroptosis

Myocardial ischemia is common in aging population. This study investigates the protective effect of Sevoflurane on myocardial ischemia reperfusion injury (MIRI) and its underlying mechanism. A total of 87 patients with a history of myocardial ischemia who underwent abdominal surgery with Sevoflurane general anesthesia were recruited in the study. The clinical data, blood pressure, heart rate, pressure-rate quotient (PRQ) and rate-pressure product (RPP) were recorded. Serum samples were collected and heart-type fatty acid binding protein (H-FABP), ischemia modified albumin (IMA), interleukin-1β (IL-1β), and interleukin-18 (IL-18) were measured to observe whether Sevoflurane anesthesia had protective effect on myocardium. In addition, MIRI rats and hypoxia/reoxygenation (H/R) injury cell model was established using neonatal rat ventricular myocytes (NRVM). Rats or NRVM were pretreated with sevoflurane for 45min before hypoxia. The mRNA expression of purinergic receptor-7 (P2X7) and NLR family pyrin domain containing 3(NLRP3) were examined. The protein expression of P2X7, NLRP3, apoptosis-associated speck-like protein (ASC), cysteine aspartic acid specific protease-1(Caspase-1), Gasdermin-D (GSDMD), Bcl-2 Associated X Protein (Bax), B-cell lymphoma-2 (Bcl-2) in myocardial tissue and cells were evaluated. The serum contents of IL-1β, IL-18, Malondialdehyde (MDA), Superoxide dismutase (SOD), Lactate dehydrogenase (LDH), Creatine kinase (CK), and Creatine kinase isoenzymes (CK-MB) were measured. The cellular localization and fluorescence intensity of NLRP3 and ASC in cells were detected. It was found that the secretion of IL-1β and IL-18 decreased in the patients. After I45 min/R3h in SD rats and H3h/R1h in NRVM, the protein expressions of P2X7, NLRP3, ASC, Caspase-1 and GSDMD were increased, the release of IL-1β, IL-18, CK, CK-MB, LDH and MDA were increased, and SOD activity was decreased. Sevoflurane treatment inhibited the high expression of P2X7, NLRP3, ASC, Caspase-1 and GSDMD, inhibited the release of LDH, CK,CK-MB and MDA in cells, and improved the activity of SOD, indicating that Sevoflurane alleviated the damage of MIRI of rats and H/R of NRVM, and had myocardial protective effect. Taken together, our study suggests that Sevoflurane inhibited the expression of IL-1β, IL-18 and GSDMD by inhibiting the P2X7-NLRP3 signaling pathway. It reduced the H/R injury of cardiomyocytes and protected the cardiac function by regulating inflammatory reaction and pyroptosis.

Perioperative Cardioprotection: Clinical Implications

Perioperative cardioprotection aims to minimize the consequences of myocardial ischemia-reperfusion injury. In isolated tissue and animal experiments, several treatments have been identified providing cardioprotection. Some of these strategies have been confirmed in clinical proof-of-concept studies. However, the final translation of cardioprotective strategies to really improve clinical outcome has been disappointing: large randomized controlled clinical trials mostly revealed inconclusive, neutral, or negative results. This review provides an overview of the currently available evidence regarding clinical implications of perioperative cardioprotective therapies from an anesthesiological perspective, highlighting nonpharmacological as well as pharmacological strategies. We discuss reasons why translation of promising experimental results into clinical practice and outcome improvement is hampered by potential confounders and suggest future perspectives to overcome these limitations.

Disease Mechanisms of Perioperative Organ Injury

Despite substantial advances in anesthesia safety within the past decades, perioperative mortality remains a prevalent problem and can be considered among the top causes of death worldwide. Acute organ failure is a major risk factor of morbidity and mortality in surgical patients and develops primarily as a consequence of a dysregulated inflammatory response and insufficient tissue perfusion. Neurological dysfunction, myocardial ischemia, acute kidney injury, respiratory failure, intestinal dysfunction, and hepatic impairment are among the most serious complications impacting patient outcome and recovery. Pre-, intra-, and postoperative arrangements, such as enhanced recovery after surgery programs, can contribute to lowering the occurrence of organ dysfunction, and mortality rates have improved with the advent of specialized intensive care units and advances in procedures relating to extracorporeal organ support. However, no specific pharmacological therapies have proven effective in the prevention or reversal of perioperative organ injury. Therefore, understanding the underlying mechanisms of organ dysfunction is essential to identify novel treatment strategies to improve perioperative care and outcomes for surgical patients. This review focuses on recent knowledge of pathophysiological and molecular pathways leading to perioperative organ injury. Additionally, we highlight potential therapeutic targets relevant to the network of events that occur in clinical settings with organ failure.

Sevoflurane as opposed to propofol anesthesia preserves mitochondrial function and alleviates myocardial ischemia/reperfusion injury

BACKGROUND

Pharmacological interventions reducing myocardial ischemia and reperfusion (I/R) injury include the administration of anesthetics. Both sevoflurane as well as propofol have been shown to elicit cardiac protection via distinct molecular mechanisms. We investigated the hypothesis that sevoflurane in contrary to propofol anesthesia elicits cardiac protection against I/R-injury via mitochondrial mechanisms of disease.

METHODS

Male New Zealand white rabbits (n = 42) were subjected 30 min of coronary artery occlusion followed by 3 h of reperfusion. After induction with pentobarbital, the animals either received sevoflurane or propofol to maintain general anesthesia. Infarct size was determined gravimetrically after triphenyltetrazolium chlorid-staining. Cardiac mitochondria were isolated and mitochondrial oxygen consumption was measured using a Clark electrode. Mitochondrial respiratory chain complex activities (I-IV) were analyzed utilizing specific assays. Data are mean ± SD.

RESULTS

Sevoflurane anesthesia significantly decreased the resulting myocardial infarct size compared to propofol anesthesia (p = 0.0275 vs. propofol). Mitochondria from animals receiving propofol anesthesia showed a significantly reduced mitochondrial respiratory control ratio (p = 0.01909 vs. sham) and impaired activities of respiratory complex I (p = 0.0147 vs. sham; p < 0.01 vs. sevoflurane) as well as respiratory complex IV (p = 0.0181 vs. sham). Mitochondrial dysfunction was absent in sevoflurane anesthesized animals. Furthermore, a significantly higher portion of complex I was found to be in its deactive form during I/R-injury in animals receiving sevoflurane anesthesia (p = 0.0123 vs. propofol).

CONCLUSIONS

Sevoflurane as opposed to propofol anesthesia preserved mitochondrial respiration and elicited cardiac protection against I/R-injury.

Effect of Hyperoxia on Myocardial Oxygenation and Function in Patients With Stable Multivessel Coronary Artery Disease

Background

The impact of hyperoxia, that is, supraphysiological arterial partial pressure of O₂, on myocardial oxygen balance and function in stable multivessel coronary artery disease (CAD) is poorly understood. In this observational study, we assessed myocardial effects of inhalational hyperoxia in patients with CAD using a comprehensive cardiovascular magnetic resonance exam.

Methods and Results

Twenty‐five patients with stable CAD underwent a contrast‐free cardiovascular magnetic resonance exam in the interval between their index coronary angiography and subsequent revascularization. The cardiovascular magnetic resonance exam involved T1 and T2 mapping for tissue characterization (fibrosis, edema) as well as function imaging, from which strain analysis was derived, and oxygenation‐sensitive cardiovascular magnetic resonance imaging. The latter modalities were both acquired at room air and after breathing pure O₂ by face mask at 10 L/min for 5 minutes. In 14 of the 25 CAD patients (56%), hyperoxia induced poststenotic myocardial deoxygenation with a subsequent oxygenation discordance across the myocardium. Extent of deoxygenation was correlated to degree of stenosis (r=−0.434, P=0.033). Hyperoxia‐associated poststenotic deoxygenation was accompanied by ipsiregional reduction of diastolic strain rate (1.39±0.57 versus 1.18±0.65; P=0.045) and systolic radial velocity (37.40±17.22 versus 32.88±13.58; P=0.038). Increased T2, as well as lower cardiac index, and defined abnormal strain parameters on room air were predictive for hyperoxia‐induced abnormalities (P<0.05). Furthermore, in patients with prolonged native T1 (>1220 ms), hyperoxia reduced ejection fraction and peak strain.

Conclusions

Patients with CAD and pre‐existent myocardial injury who respond to hyperoxic challenge with strain abnormalities appear susceptible for hyperoxia‐induced regional deoxygenation and deterioration of myocardial function.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT02233634.

Myocardial Injury After Noncardiac Surgery: A Systematic Review and Meta-Analysis

Myocardial injury after noncardiac surgery (MINS) is a common postoperative complication associated with adverse cardiovascular outcomes. The purpose of this systematic review was to determine the incidence, clinical features, pathogenesis, management, and outcomes of MINS. We searched PubMed, Embase, Central and Web of Science databases for studies reporting the incidence, clinical features, and prognosis of MINS. Data analysis was performed with a mixed-methods approach, with quantitative analysis of meta-analytic methods for incidence, management, and outcomes, and a qualitative synthesis of the literature to determine associated preoperative factors and MINS pathogenesis. A total of 195 studies met study inclusion criteria. Among 169 studies reporting outcomes of 530,867 surgeries, the pooled incidence of MINS was 17.9% [95% confidence interval (CI), 16.2-19.6%]. Patients with MINS were older, more frequently men, and more likely to have cardiovascular risk factors and known coronary artery disease. Postoperative mortality was higher among patients with MINS than those without MINS, both in-hospital (8.1%, 95% CI, 4.4-12.7% vs 0.4%, 95% CI, 0.2-0.7%; relative risk 8.3, 95% CI, 4.2-16.6, P < 0.001) and at 1-year after surgery (20.6%, 95% CI, 15.9-25.7% vs 5.1%, 95% CI, 3.2-7.4%; relative risk 4.1, 95% CI, 3.0-5.6, P < 0.001). Few studies reported mechanisms of MINS or the medical treatment provided. In conclusion, MINS occurs frequently in clinical practice, is most common in patients with cardiovascular disease and its risk factors, and is associated with increased short- and long-term mortality. Additional investigation is needed to define strategies to prevent MINS and treat patients with this diagnosis.

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.

The effect of perioperative anesthetics for prevention of postoperative delirium on general anesthesia: A network meta-analysis

STUDY OBJECTIVE

Postoperative delirium (POD) is a common neurological system disorder in surgical patients. Anesthesia providers have a wide choice of sedative agents involving different mechanisms in clinical practice, and the incidence of POD varies regarding which sedative agent administered. This network meta-analysis aimed to comprehensively analyze the safety and efficacy of each choice for patients.

DESIGN

A network meta-analysis.

SETTING

Vanderbilt University Medical Center.

MEASUREMENTS

We searched PubMed, EMBASE, Ovid Medline and Cochrane Central Register of Controlled Trials (CENTRAL) through the end of September 2018 with the registration number CRD42018110585. The randomized controlled trials were identified and extracted by two reviewers independently. Commonly used sedative agents such as placebo, sevoflurane, desflurane, isoflurane, dexmedetomidine, propofol, midazolam, and ketamine were assessed in this network meta-analysis and the primary outcome was the incidence of POD. The data were synthesized by network meta-analysis. Pair-wise meta-analyses were conducted using the random-effects model. Each intervention was ranked according to its corresponding surface under the cumulative ranking curve (SUCRA) values. The GRADE framework was undertaken to evaluate the risk of bias.

MAIN RESULTS

We identified 39 RCTs and 5991 patients in this meta-analysis. Dexmedetomidine was found to be the most effective option in reducing POD, compared to midazolam, propofol, desflurane, and sevoflurane. The results revealed that dexmedetomidine was associated with a lower incidence of POD, whereas midazolam was associated with a significantly higher number of patients with delirium. Midazolam and propofol were also associated with a higher incidence of perioperative hypotension and bradycardia.

CONCLUSION

Our study provided meta-analytic evidence and suggested dexmedetomidine could be considered as the most effective sedative agent to reduce POD. However, clinical practitioners still need to weigh the pros and cons before choosing a sedative agent for individual patient.

Effects of Volatile versus Total Intravenous Anesthesia on Occurrence of Myocardial Injury after Non-Cardiac Surgery

The cardioprotective effects of volatile anesthetics versus total intravenous anesthesia (TIVA) are controversial, especially in patients undergoing non-cardiac surgery. Using current generation high-sensitivity cardiac troponin (hs-cTn), we aimed to evaluate the effect of anesthetics on the occurrence of myocardial injury after non-cardiac surgery (MINS). From February 2010 to December 2016, 3555 patients without preoperative hs-cTn elevation underwent non-cardiac surgery under general anesthesia. Patients were grouped according to anesthetic agent; 659 patients were classified into a propofol-remifentanil total intravenous anesthesia (TIVA) group, and 2896 patients were classified into a volatile group. To balance the use of remifentanil between groups, a balanced group (n = 1622) was generated with patients who received remifentanil infusion in the volatile group, and two separate comparisons were performed (TIVA vs. volatile and TIVA vs. balanced). The primary outcome was occurrence of MINS, defined as rise of hs-cTn I ≥ 0.04 ng/mL within postoperative 48 hours. The secondary outcomes were 30-day mortality, postoperative acute kidney injury (AKI), and adverse events during hospital stay (mortality, type I myocardial infarction (MI), and new-onset arrhythmia). In propensity-matched analyses, the occurrence of MINS was lower in the TIVA group compared to the volatile group (OR 0.642; 95% CI 0.450–0.914; p = 0.014). However, after balancing the use of remifentanil, there was no difference between groups in the risk of MINS (OR 0.832; 95% CI 0.554–1.251; p-value = 0.377). There were no significant associations between the two groups in type 1 MI, new-onset atrial fibrillation, in-hospital and 30-day mortality before and after balancing the use of remifentanil. However, the incidence of postoperative AKI was lower in the TIVA group (OR 0.362; 95% CI 0.194–0.675; p-value = 0.001). After balancing the use of remifentanil, volatile anesthesia and TIVA showed comparable effects on MINS in patients undergoing non-cardiac surgery without preoperative myocardial injury. Further studies are needed on the benefit of remifentanil infusion.

Cardioprotective effect of transcutaneous electrical acupuncture point stimulation on perioperative elderly patients with coronary heart disease: a prospective, randomized, controlled clinical trial

Purpose

The purpose of this study was to evaluate the effects of transcutaneous electrical acupoint stimulation (TEAS) on postoperative autonomic nervous system function and serum biomarkers in the elderly.

Patients and methods

A total of 122 American Society of Anesthesiologists class II or III patients with coronary heart disease undergoing spinal surgery were randomly divided into two groups: TEAS (received TEAS at Neiguan [PC6] and Ximen [PC4] for 30 minutes before anesthesia induction until the end of surgery) and control (received electrode plate at the same acupuncture points without any electrical stimulation). Serum was isolated for the measurement of concentration of high-sensitive troponin T (hs-cTnT), CRP, and CK. Heart rate (HR) and heart rate variability (HRV) including: total power (TP), low-frequency (LF) power, high-frequency (HF) power, and LF/HF ratio were used to assess autonomic nervous system function. The primary outcome was to evaluate whether TEAS changed the postoperative serum hs-cTnT. The secondary outcomes were to observe the effects of TEAS on HRV, circulating CK and CRP after surgery.

Results

Hs-cTnT, CRP, and CK concentrations were significantly higher on first, third and fifth day after surgery than those before anesthesia induction in both groups. Hs-cTnT concentration was significantly lower on the first and third day after surgery in TEAS group than in control group. Compared with 1 day before surgery, TP, LF, and HF decreased significantly and HR, LF/HF increased significantly on first, third, and fifth day after surgery in control group. Compared with control group, HR was significantly lower on the first, third, and fifth day after surgery, LF/HF decreased and TP, LF, HF were significantly higher on the first day after surgery in TEAS group.

Conclusion

TEAS at PC6 and PC4 could reduce postoperative serum hs-cTnT concentration and change HRV index to improve autonomic nervous system activity.

A systematic review and meta-analysis of remote ischemic preconditioning for vascular surgery

BACKGROUND

Remote ischemic preconditioning (RIPC) is a method of preparing the body for a later prolonged ischemic episode to protect against subsequent detrimental effects. This study aimed to identify the effects of RIPC in vascular surgery.

METHODS

A standard Preferred Reporting Items for Systematic Reviews and Meta-Analyses search was conducted of randomized controlled trials of RIPC in patients undergoing open or endovascular aneurysm repair, carotid endarterectomy, or lower limb bypass reporting on mortality and renal or cardiac outcomes. Random-effects meta-analysis was performed using Review Manager 5.3 (The Nordic Cochrane Center, Copenhagen, Denmark).

RESULTS

A total of 13 randomized controlled trials in the meta-analysis included 548 patients in the RIPC cohort and 549 controls. There was no significant difference in mortality, renal dysfunction, myocardial infarction, myocardial injury, or length of stay between the groups, with subgroup and sensitivity analysis showing no significant difference.

CONCLUSIONS

Current evidence demonstrates no benefit of RIPC in vascular surgery. Further large multicenter trials of RIPC in major vascular surgery should be considered.

Propofol vs. inhalational agents to maintain general anaesthesia in ambulatory and in-patient surgery: a systematic review and meta-analysis

Background

It is unclear if anaesthesia maintenance with propofol is advantageous or beneficial over inhalational agents. This study is intended to compare the effects of propofol vs. inhalational agents in maintaining general anaesthesia on patient-relevant outcomes and patient satisfaction.

Methods

Studies were identified by electronic database searches in PubMed™, EMBASE™ and the Cochrane™ library between 01/01/1985 and 01/08/2016. Randomized controlled trials (RCTs) of peer-reviewed journals were studied. Of 6688 studies identified, 229 RCTs were included with a total of 20,991 patients. Quality control, assessment of risk of bias, meta-bias, meta-regression and certainty in evidence were performed according to Cochrane. Common estimates were derived from fixed or random-effects models depending on the presence of heterogeneity. Post-operative nausea and vomiting (PONV) was the primary outcome. Post-operative pain, emergence agitation, time to recovery, hospital length of stay, post-anaesthetic shivering and haemodynamic instability were considered key secondary outcomes.

Results

The risk for PONV was lower with propofol than with inhalational agents (relative risk (RR) 0.61 [0.53, 0.69], p < 0.00001). Additionally, pain score after extubation and time in the post-operative anaesthesia care unit (PACU) were reduced with propofol (mean difference (MD) − 0.51 [− 0.81, − 0.20], p = 0.001; MD − 2.91 min [− 5.47, − 0.35], p = 0.03). In turn, time to respiratory recovery and tracheal extubation were longer with propofol than with inhalational agents (MD 0.82 min [0.20, 1.45], p = 0.01; MD 0.70 min [0.03, 1.38], p = 0.04, respectively). Notably, patient satisfaction, as reported by the number of satisfied patients and scores, was higher with propofol (RR 1.06 [1.01, 1.10], p = 0.02; MD 0.13 [0.00, 0.26], p = 0.05). Secondary analyses supported the primary results.

Conclusions

Based on the present meta-analysis there are several advantages of anaesthesia maintenance with propofol over inhalational agents. While these benefits result in an increased patient satisfaction, the clinical and economic relevance of these findings still need to be addressed in adequately powered prospective clinical trials.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0632-3) contains supplementary material, which is available to authorized users.

Comparison of the expression of cluster of differentiation (CD)39 and CD73 between propofol- and sevoflurane-based anaesthesia during open heart surgery

High expression of cluster of differentiation (CD)39 and CD73 has cardio-protective effects. We hypothesised that the expression of CD39 and CD73 would differ between propofol- and volatile anaesthetic-based anaesthesia in patients undergoing open heart surgery (OHS). The objective of this prospective randomized trial was to compare the changes in CD39 and CD73 levels in CD4+ T cells between propofol- and sevoflurane-based anaesthesia during OHS. The study randomly allocated 156 patients undergoing OHS to a propofol or sevoflurane group. Blood was obtained preoperatively and up to 48 hours after weaning from cardiopulmonary bypass (CPB). The expression levels of CD39 and CD73 in circulating CD4+ T cells, serum cytokines and other laboratory parameters were analysed. The primary outcome was the expression of CD39 and CD73 on CD4+ T cells. Demographic data and perioperative haemodynamic changes did not show significant differences between the two groups. The expression of CD39 and CD73 in the sevoflurane group was significantly lower than in the propofol group (P < 0.001). Other laboratory findings including cardiac enzymes and cytokine levels, did not show significant intergroup differences. Propofol attenuated the decrease in CD39 and CD73 in circulating CD4+ T cells compared to sevoflurane-based anaesthesia during OHS.

Delirium in Older Persons: Advances in Diagnosis and Treatment

Importance

Delirium is defined as an acute disorder of attention and cognition. It is a common, serious, and often fatal condition among older patients. Although often underrecognized, delirium has serious adverse effects on the individual's function and quality of life, as well as broad societal effects with substantial health care costs.

Objective

To summarize the current state of the art in diagnosis and treatment of delirium and to highlight critical areas for future research to advance the field.

Evidence Review

Search of Ovid MEDLINE, Embase, and the Cochrane Library for the past 6 years, from January 1, 2011, until March 16, 2017, using a combination of controlled vocabulary and keyword terms. Since delirium is more prevalent in older adults, the focus was on studies in elderly populations; studies based solely in the intensive care unit (ICU) and non-English-language articles were excluded.

Findings

Of 127 articles included, 25 were clinical trials, 42 cohort studies, 5 systematic reviews and meta-analyses, and 55 were other categories. A total of 11 616 patients were represented in the treatment studies. Advances in diagnosis have included the development of brief screening tools with high sensitivity and specificity, such as the 3-Minute Diagnostic Assessment; 4 A's Test; and proxy-based measures such as the Family Confusion Assessment Method. Measures of severity, such as the Confusion Assessment Method-Severity Score, can aid in monitoring response to treatment, risk stratification, and assessing prognosis. Nonpharmacologic approaches focused on risk factors such as immobility, functional decline, visual or hearing impairment, dehydration, and sleep deprivation are effective for delirium prevention and also are recommended for delirium treatment. Current recommendations for pharmacologic treatment of delirium, based on recent reviews of the evidence, recommend reserving use of antipsychotics and other sedating medications for treatment of severe agitation that poses risk to patient or staff safety or threatens interruption of essential medical therapies.

Conclusions and Relevance

Advances in diagnosis can improve recognition and risk stratification of delirium. Prevention of delirium using nonpharmacologic approaches is documented to be effective, while pharmacologic prevention and treatment of delirium remains controversial.

Randomized comparison of sevoflurane versus propofol-remifentanil on the cardioprotective effects in elderly patients with coronary heart disease

Background

It is skeptical about cardioprotective property of sevoflurane in patients undergoing noncardiac surgery, especially in the elderly patients with coronary heart disease. We hypothesized that long duration of sevoflurane inhalation in noncardiac surgery could ameliorate myocardial damage in such patients.

Methods

This was a randomized, prospective study. One hundred twenty-one elderly patients with coronary heart disease were randomly allocated into two groups. Maintenance of anesthesia was achieved by sevoflurane inhalation (Group S) or propofol-remifentanil respectively (Group PR). Serum cardiac troponin I (cTnI) and brain natriuretic peptide (BNP) were measured before anesthesia induction (T0), 8 h (T1) and 24 h (T2) after anesthesia respectively. The perioperative cardiac output, complications and postoperative 3-month follow-up from end of surgery were recorded.

Results

Between the two groups, there were no statistical differences in the values of cTnI and BNP during the study. However, The area under the curve of cTnI values over 24 h after operation was less in Group S. Group PR had lower cardiac output and consumed more amount of phenylephrine during the study (P < 0.05).

Conclusions

Compared with the group PR, sevoflurane had no benefit in the myocardial protection for the elderly patients with CHD. However, Sevoflurane showed advantage in maintaining hemodynamic stability during the operative period.

Trial registration

Chinese Clinical Trial Registry, ChiCTR-IPR-16008871, 21 July 2016.

Economic Evaluation of Pharmacologic Pre- and Postconditioning With Sevoflurane Compared With Total Intravenous Anesthesia in Liver Surgery: A Cost Analysis

BACKGROUND

Pharmacologic pre- and postconditioning with sevoflurane compared with total IV anesthesia in patients undergoing liver surgery reduced complication rates as shown in 2 recent randomized controlled trials. However, the potential health economic consequences of these different anesthesia regimens have not yet been assessed.

METHODS

An expostcost analysis of these 2 trials in 129 patients treated between 2006 and 2010 was performed. We analyzed direct medical costs for in-hospital stay and compared pharmacologic pre- and postconditioning with sevoflurane (intervention) with total IV anesthesia (control) from the perspective of a Swiss university hospital. Year 2015 costs, converted to US dollars, were derived from hospital cost accounting data and compared with a multivariable regression analysis adjusting for relevant covariables. Costs with negative prefix indicate savings and costs with positive prefix represent higher spending in our analysis.

RESULTS

Treatment-related costs per patient showed a nonsignificant change by -12,697 US dollars (95% confidence interval [CI], 10,956 to -36,352; P = .29) with preconditioning and by -6139 US dollars (95% CI, 6723 to -19,000; P = .35) with postconditioning compared with the control group. Results were robust in our sensitivity analysis. For both procedures (control and intervention) together, major complications led to a significant increase in costs by 86,018 US dollars (95% CI, 13,839-158,198; P = .02) per patient compared with patients with no major complications.

CONCLUSIONS

In this cost analysis, reduced in-hospital costs by pharmacologic conditioning with sevoflurane in patients undergoing liver surgery are suggested. This possible difference in costs compared with total IV anesthesia is the result of reduced complication rates with pharmacologic conditioning, because major complications have significant cost implications.

A clinical review of inhalation anesthesia with sevoflurane: from early research to emerging topics

A large number of studies during the past two decades have demonstrated the efficacy and safety of sevoflurane across patient populations. Clinical researchers have also investigated the effects of sevoflurane, its hemodynamic characteristics, its potential protective effects on several organ systems, and the incidence of delirium and cognitive deficiency. This review examines the clinical profiles of sevoflurane and other anesthetic agents, and focuses upon emerging topics such as organ protection, postoperative cognitive deficiency and delirium, and novel ways to improve postanesthesia outcomes.

A randomised trial of peri-operative positive airway pressure for postoperative delirium in patients at risk for obstructive sleep apnoea after regional anaesthesia with sedation or general anaesthesia for joint arthroplasty

Previous pilot work has established an association between obstructive sleep apnoea and the development of acute postoperative delirium , but it remains unclear to what extent this risk factor is modifiable in the 'real world' peri-operative setting. In a single-blind randomised controlled trial, 135 elderly surgical patients at risk for obstructive sleep apnoea were randomly assigned to receive peri-operative continuous positive airway pressure (CPAP) or routine care. Of the 114 patients who completed the study, 21 (18.4%) experienced delirium. Delirium was equally common in both groups: 21% (12 of 58 subjects) in the CPAP group and 16% (9 of 56 subjects) in the routine care group (OR = 1.36 [95%CI 0.52-3.54], p = 0.53). Delirious subjects were slightly older - mean (SD) age 68.9 (10.7) vs. 64.9 (8.2), p = 0.07 - but had nearly identical pre-operative STOP-Bang scores (4.19 (1.1) versus 4.27 (1.3), p = 0.79). Subjects in the CPAP group used their devices for a median (IQR [range]) of 3 (0.25-5 [0-12]) nights pre-operatively (2.9 (0.1-4.8 [0.0-12.7]) hours per night) and 1 (0-2 [0-2]) nights postoperatively (1.4 (0.0-5.1 [0.0-11.6]) hours per night). Among the CPAP subjects, the residual pre-operative apnoea-hypopnea index had a significant effect on delirium severity (p = 0.0002). Although we confirm that apnoea is associated with postoperative delirium, we did not find that providing a short-course of auto-titrating CPAP affected its likelihood or severity. Voluntary adherence to CPAP is particularly poor during the initiation of therapy.

Cardiac Evaluation and Monitoring of Patients Undergoing Noncardiac Surgery

Surgical management of disease has a tremendous impact on our health system. Millions of people worldwide undergo surgeries every year. Cardiovascular complications in the perioperative period are one of the most common events leading to increased morbidity and mortality. Although such events are very small in number, they are associated with a high mortality rate making it essential for physicians to understand the importance of perioperative cardiovascular risk assessment and evaluation. Its involves a detailed process of history taking, patient's medical profile, medications being used, functional status of the patient, and knowledge about the surgical procedure and its inherent risks. Different risk assessment tools and calculators have also been developed to aid in this process, each with their own advantages and limitations. After such a comprehensive evaluation, a physician will be able to provide a risk assessment or it may all lead to further testing if it is believed that a change in management after such testing will help to reduce perioperative morbidity and mortality. There is extensive literature on the significance of multiple perioperative testing modalities and how they can change management. The purpose of our review is to provide a concise but comprehensive analysis on all such aspects of perioperative cardiovascular risk assessment for noncardiac surgeries and provide a basic methodology toward such assessment and decision making.

Which Anesthesia Regimen Is Best to Reduce Morbidity and Mortality in Lung Surgery?

Background

One-lung ventilation during thoracic surgery is associated with hypoxia–reoxygenation injury in the deflated and subsequently reventilated lung. Numerous studies have reported volatile anesthesia–induced attenuation of inflammatory responses in such scenarios. If the effect also extends to clinical outcome is yet undetermined. We hypothesized that volatile anesthesia is superior to intravenous anesthesia regarding postoperative complications.

Methods

Five centers in Switzerland participated in the randomized controlled trial. Patients scheduled for lung surgery with one-lung ventilation were randomly assigned to one of two parallel arms to receive either propofol or desflurane as general anesthetic. Patients and surgeons were blinded to group allocation. Time to occurrence of the first major complication according to the Clavien-Dindo score was defined as primary (during hospitalization) or secondary (6-month follow-up) endpoint. Cox regression models were used with adjustment for prestratification variables and age.

Results

Of 767 screened patients, 460 were randomized and analyzed (n = 230 for each arm). Demographics, disease and intraoperative characteristics were comparable in both groups. Incidence of major complications during hospitalization was 16.5% in the propofol and 13.0% in the desflurane groups (hazard ratio for desflurane vs. propofol, 0.75; 95% CI, 0.46 to 1.22; P = 0.24). Incidence of major complications within 6 months from surgery was 40.4% in the propofol and 39.6% in the desflurane groups (hazard ratio for desflurane vs. propofol, 0.95; 95% CI, 0.71 to 1.28; P = 0.71).

Conclusions

This is the first multicenter randomized controlled trial addressing the effect of volatile versus intravenous anesthetics on major complications after lung surgery. No difference between the two anesthesia regimens was evident.

Effects of Volatile Anesthetics on Mortality and Postoperative Pulmonary and Other Complications in Patients Undergoing Surgery

Background

It is not known whether modern volatile anesthetics are associated with less mortality and postoperative pulmonary or other complications in patients undergoing general anesthesia for surgery.

Methods

A systematic literature review was conducted for randomized controlled trials fulfilling following criteria: (1) population: adult patients undergoing general anesthesia for surgery; (2) intervention: patients receiving sevoflurane, desflurane, or isoflurane; (3) comparison: volatile anesthetics versus total IV anesthesia or volatile anesthetics; (4) reporting on: (a) mortality (primary outcome) and (b) postoperative pulmonary or other complications; (5) study design: randomized controlled trials. The authors pooled treatment effects following Peto odds ratio (OR) meta-analysis and network meta-analysis methods.

Results

Sixty-eight randomized controlled trials with 7,104 patients were retained for analysis. In cardiac surgery, volatile anesthetics were associated with reduced mortality (OR = 0.55; 95% CI, 0.35 to 0.85; P = 0.007), less pulmonary (OR = 0.71; 95% CI, 0.52 to 0.98; P = 0.038), and other complications (OR = 0.74; 95% CI, 0.58 to 0.95; P = 0.020). In noncardiac surgery, volatile anesthetics were not associated with reduced mortality (OR = 1.31; 95% CI, 0.83 to 2.05, P = 0.242) or lower incidences of pulmonary (OR = 0.67; 95% CI, 0.42 to 1.05; P = 0.081) and other complications (OR = 0.70; 95% CI, 0.46 to 1.05; P = 0.092).

Conclusions

In cardiac, but not in noncardiac, surgery, when compared to total IV anesthesia, general anesthesia with volatile anesthetics was associated with major benefits in outcome, including reduced mortality, as well as lower incidence of pulmonary and other complications. Further studies are warranted to address the impact of volatile anesthetics on outcome in noncardiac surgery.