Nonsurgical Strategies to Reduce Mortality in Patients Undergoing Cardiac Surgery: An Updated Consensus Process

Effect of volatile versus propofol anaesthesia on major complications and mortality after cardiac surgery: a multicentre randomised trial

BACKGROUND

The comparative effectiveness of volatile anaesthesia and total intravenous anaesthesia (TIVA) in terms of patient outcomes after cardiac surgery remains a topic of debate.

METHODS

Multicentre randomised trial in 16 tertiary hospitals in China. Adult patients undergoing elective cardiac surgery were randomised in a 1:1 ratio to receive volatile anaesthesia (sevoflurane or desflurane) or propofol-based TIVA. The primary outcome was a composite of predefined major complications during hospitalisation and mortality 30 days after surgery.

RESULTS

Of the 3123 randomised patients, 3083 (98.7%; mean age 55 yr; 1419 [46.0%] women) were included in the modified intention-to-treat analysis. The composite primary outcome was met by a similar number of patients in both groups (volatile group: 517 of 1531 (33.8%) patients vs TIVA group: 515 of 1552 (33.2%) patients; relative risk 1.02 [0.92-1.12]; P=0.76; adjusted odds ratio 1.05 [0.90-1.22]; P=0.57). Secondary outcomes including 6-month and 1-yr mortality, duration of mechanical ventilation, length of ICU and hospital stay, and healthcare costs, were also similar for the two groups.

CONCLUSIONS

Among adults undergoing cardiac surgery, we found no difference in the clinical effectiveness of volatile anaesthesia and propofol-based TIVA.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR-IOR-17013578).

Vacuum-assisted closure therapy for the management of deep sternal wound complications: A systematic review and meta-analysis

BACKGROUND

Vacuum-assisted closure (VAC) therapy has become a popular treatment option for wound healing. The aim of this meta-analysis was to assess the use of VAC therapy as a bridge before the definitive treatment for the management of deep sternal wound complications.

METHODS

A systematic literature review and meta-analysis were performed in PubMed and Embase. Outcomes of interest included mortality, treatment failure, length of hospital stay (LOS), length of intensive care unit (ICU) stay and cost of treatment.

RESULTS

Twenty-two studies involving 1980 patients were included in the quantitative synthesis of this meta-analysis. Patients treated with VAC had significantly lower overall mortality [1738 patients; Risk ratio [RR] = 0.36 (95% confidence interval [CI]: 0.25, 0.51)], treatment failure [1210 patients; RR = 0.26 (95% CI: 0.19, 0.37)], LOS [498 patients; (standard mean difference = -0.44 (95% CI: -0.81, -0.07)] and ICU stay [309 patients; (standard mean difference = -0.34 (95% CI: -0.67, -0.01)] compared to that of non-VAC patients. VAC therapy was associated with reduced cost of treatment per patient compared with that of non-VAC therapies (reductions of 3600 USD, 6000 USD and 8983 USD in the reported studies).

CONCLUSIONS

VAC therapy as an adjunct in the definitive treatment of patients with deep sternal wound complications was associated with lower mortality, treatment failure, LOS, ICU stay and cost of treatment when compared with a non-VAC approach. Randomised controlled trials would be essential to confirm these findings.

Acute Glycemic Variability and Early Outcomes After Cardiac Surgery: A Meta-Analysis

The influence of acute glycemic variability (GV) on early outcomes of patients after cardiac surgery remains not fully determined. We performed a systematic review and meta-analysis to evaluate the association between acute GV and in-hospital outcomes of patients after cardiac surgery. Relevant observational studies were obtained by search of electronic databases including Medline, Embase, Cochrane Library, and Web of Science. A randomized-effects model was selected to pool the data by incorporating the influence of potential heterogeneity. Nine cohort studies involving 16 411 patients after cardiac surgery were included in this meta-analysis. Pooled results showed that a high acute GV was associated with an increased risk of major adverse events (MAE) during hospitalization for patients after cardiac surgery [odds ratio [OR]: 1.29, 95% CI: 1.15 to 1.45, p<0.001, I22=38%]. Sensitivity analysis limited to studies of on-pump surgery and GV evaluated by coefficient of variation of blood glucose showed similar results. Subgroup analysis suggested that a high acute GV was related to an increased incidence of MAE in patients after coronary artery bypass graft, but not for those after isolated valvular surgery (p=0.04), and the association was weakened after adjustment of glycosylated hemoglobin (p=0.01). Moreover, a high acute GV was also related to an increased risk of in-hospital mortality (OR: 1.55, 95% CI: 1.15 to 2.09, p=0.004; I22=0%). A high acute GV may be associated with poor in-hospital outcomes in patients after cardiac surgery.

Beneficial effects of levosimendan to wean patients from VA-ECMO: a systematic review and meta-analysis

INTRODUCTION

Patients with refractory cardiogenic shock can benefit from veno-arterial extracorporeal membrane oxygenation (VA-ECMO). The use of levosimendan in VA-ECMO patients may facilitate weaning and enhance survival.

EVIDENCE ACQUISITION

MEDLINE, Scopus, Web of Science, and Cochrane were searched from inception to October 10th, 2021. Eligible clinical trials and observational studies reporting the use of levosimendan in VA-ECMO were searched. Two reviewers extracted data and independently assessed the risk of bias. To integrate the data, a random-effect model was applied. The success of weaning from VA-ECMO was the primary outcome.

EVIDENCE SYNTHESIS

Ten observational studies, including a total of 987 patients, were identified. Levosimendan was associated with successful weaning (362/448) compared with controls (328/539) (OR 2.37, 95% CI 1.71-3.28; P=0.01) and reduced mortality (144/433 vs. 258/507) (nine studies, OR 0.53, 95% CI 0.36-0.78; P=0.01) compared with control.

CONCLUSIONS

Levosimendan was associated with successful weaning and increased survival in VA-ECMO patients. Randomized trials should confirm these findings.

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.

Effect of Volatile Anesthetics on Myocardial Infarction After Coronary Artery Surgery: A Post Hoc Analysis of a Randomized Trial

OBJECTIVE

To investigate the effect of volatile anesthetics on the rates of postoperative myocardial infarction (MI) and cardiac death after coronary artery bypass graft (CABG).

DESIGN

A post hoc analysis of a randomized trial.

SETTING

Cardiac surgical operating rooms.

PARTICIPANTS

Patients undergoing elective, isolated CABG.

INTERVENTIONS

Patients were randomized to receive a volatile anesthetic (desflurane, isoflurane, or sevoflurane) or total intravenous anesthesia (TIVA). The primary outcome was hemodynamically relevant MI (MI requiring high-dose inotropic support or prolonged intensive care unit stay) occurring within 48 hours from surgery. The secondary outcome was 1-year death due to cardiac causes.

MEASUREMENTS AND MAIN RESULTS

A total of 5,400 patients were enrolled between April 2014 and September 2017 (2,709 patients randomized to the volatile anesthetics group and 2,691 to TIVA). The mean age was 62 ± 8.4 years, and the median baseline ejection fraction was 57% (50-67), without differences between the 2 groups. Patients in the volatile group had a lower incidence of MI with hemodynamic complications both in the per-protocol (14 of 2,530 [0.6%] v 27 of 2,501 [1.1%] in the TIVA group; p = 0.038) and as-treated analyses (16 of 2,708 [0.6%] v 29 of 2,617 [1.1%] in the TIVA group; p = 0.039), but not in the intention-to-treat analysis (17 of 2,663 [0.6%] v 28 of 2,667 [1.0%] in the TIVA group; p = 0.10). Overall, deaths due to cardiac causes were lower in the volatile group (23 of 2,685 [0.9%] v 40 of 2,668 [1.5%] than in the TIVA group; p = 0.03).

CONCLUSIONS

An anesthetic regimen, including volatile agents, may be associated with a lower rate of postoperative MI with hemodynamic complication in patients undergoing CABG. Furthermore, it may reduce long-term cardiac mortality.

Prophylactic tranexamic acid use in non-cardiac surgeries at high risk for transfusion

BACKGROUND

Tranexamic acid (TXA) reduces transfusion in a wide range of surgical populations, although its real-world use in non-cardiac surgeries has not been well described. The objective of this study was to describe prophylactic TXA use in non-cardiac surgeries at high risk for transfusion.

METHODS

This is a retrospective cohort study of all adult patients undergoing major non-cardiac surgery at ≥5% risk of perioperative transfusion at five Canadian hospitals between January 2014 and December 2016. Canadian Classification of Health Interventions procedure codes within the Discharge Abstract Database were linked to transfusion and laboratory databases. TXA use was ascertained electronically from The Ottawa Hospital Data Warehouse and via manual chart review for Winnipeg hospitals. For each surgery, we evaluated the percentage of patients who received TXA as well as the specifics of TXA dosing and administration.

RESULTS

TXA use was evaluable in 14 300 patients. Overall, 17% of surgeries received TXA, ranging from 0% to 68% among individual surgeries. TXA use was more common in orthopaedic (n = 2043/4942; 41%) and spine surgeries (n = 239/1322; 18%) compared to other surgical domains (n = 109/8036; 1%). TXA was commonly administered as a bolus (n = 2097/2391; 88%). The median TXA dose was 1000 mg (IQR 1000-1000 mg).

CONCLUSION

TXA is predominantly used in orthopaedic and spine surgeries, with little uptake in other non-cardiac surgeries at high risk for red blood cell transfusion. Further studies are needed to evaluate the effectiveness and safety of TXA and to understand the barriers to TXA administration in a broad range of non-cardiac surgeries.

An update on levosimendan in acute cardiac care: applications and recommendations for optimal efficacy and safety

Introduction: In the 20 years since its introduction to the palette of intravenous hemodynamic therapies, the inodilator levosimendan has established itself as a valuable asset for the management of acute decompensated heart failure. Its pharmacology is notable for delivering inotropy via calcium sensitization without an increase in myocardial oxygen consumption.Areas covered: Experience with levosimendan has led to its applications expanding into perioperative hemodynamic support and various critical care settings, as well as an array of situations associated with acutely decompensated heart failure, such as right ventricular failure, cardiogenic shock with multi-organ dysfunction, and cardio-renal syndrome. Evidence suggests that levosimendan may be preferable to milrinone for patients in cardiogenic shock after cardiac surgery or for weaning from extracorporeal life support and may be superior to dobutamine in terms of short-term survival, especially in patients on beta-blockers. Positive effects on kidney function have been noted, further differentiating levosimendan from catecholamines and phosphodiesterase inhibitors.Expert opinion:Levosimendan can be a valuable resource in the treatment of acute cardiac dysfunction, especially in the presence of beta-blockers or ischemic cardiomyopathy. When attention is given to avoiding or correcting hypovolemia and hypokalemia, an early use of the drug in the treatment algorithm is preferred.

Variation in prophylactic tranexamic acid administration among anesthesiologists and surgeons in orthopedic surgery: a retrospective cohort study

PURPOSE

Tranexamic acid (TXA) reduces red blood cell transfusion in various orthopedic surgeries, yet the degree of practice variation in its use among anesthesiologists and surgeons has not been described. To target future knowledge transfer and implementation strategies, and to better understand determinants of variability in prophylactic TXA use, our primary objective was to evaluate the influence of surgical team members on the variability of prophylactic TXA administration.

METHODS

This was a retrospective cohort study of all adult patients undergoing primary total hip arthroplasty (THA), hip fracture surgery, and spine fusion ± vertebrectomy at two Canadian hospitals between January 2014 and December 2016. We used Canadian Classification of Health Interventions procedure codes within the Discharge Abstract Database which we linked to the Ottawa Data Warehouse. We described the percentage of patients that received TXA by individual surgery, the specifics of TXA dosing, and estimated the effect of anesthesiologists and surgeons on prophylactic TXA using multivariable mixed-effects logistic regression analyses.

RESULTS

In the 3,900 patients studied, TXA was most commonly used in primary THA (85%; n = 1,344/1,582), with lower use in hip fracture (23%; n = 342/1,506) and spine fusion surgery (23%; n = 186/812). The median [interquartile range] total TXA dose was 1,000 [1,000-1,000] mg, given as a bolus in 92% of cases. Anesthesiologists and surgeons added significant variability to the odds of receiving TXA in hip fracture surgery and spine fusion, but not primary THA. Most of the variability in TXA use was attributed to patient and other factors.

CONCLUSION

We confirmed the routine use of TXA in primary THA, while observing lower utilization with more variability in hip fracture and spine fusion surgery. Further study is warranted to understand variations in use and the barriers to TXA implementation in a broader population of orthopedic surgical patients at high risk for transfusion.

Preoperative, Multidisciplinary Clinical Optimization of Patients with Severely Depressed Left Ventricular Ejection Fraction Who Are Undergoing Coronary Artery Bypass Grafting

Coronary artery bypass grafting (CABG) remains a routine operation despite major advancements in angioplastic procedures. Around 200,000 CABG procedures are performed annually in the U.S. Patients who are not candidates for angioplasty intervention often have advanced coronary disease and comorbidities that raise the risk of heart failure with decreased ejection fraction to around 25%. Over the years, significant developments in various preoperative interventions have occurred; in this paper, we suggest a multidisciplinary preoperative algorithm that can be included in a regularly scheduled multidisciplinary care plan.

Sevoflurane prevents vulnerable plaque disruption in apolipoprotein E-knockout mice by increasing collagen deposition and inhibiting inflammation

BACKGROUND

Sevoflurane may reduce the occurrence of major adverse cardiovascular events (MACCEs) in surgical patients, although the mechanisms are poorly understood. We hypothesised that sevoflurane stabilises atherosclerotic plaques by inhibiting inflammation and enhancing prolyl-4-hydroxylase α1 (P4Hα1), the rate-limiting subunit for the P4H enzyme essential for collagen synthesis.

METHODS

We established a vulnerable arterial plaque model in apolipoprotein E-knockout mice (ApoE^-/-) fed a high-fat diet that underwent daily restraint/noise stress, with/without a single prior exposure to sevoflurane for 6 h (1-3%; n=30 per group). In vitro, smooth muscle cells (SMCs) were incubated with tumour necrosis factor-alpha in the presence/absence of sevoflurane. Immunohistochemistry, immunoblots, and mRNA concentrations were used to quantify the effect of sevoflurane on plaque formation, expression of inflammatory cytokines, P4Hα1, and collagen subtypes in atherosclerotic plaques or isolated SMCs.

RESULTS

In ApoE^-/- mice, inhalation of sevoflurane 1-3% for 6 h reduced the aortic plaque size by 8-29% in a dose-dependent manner, compared with control mice that underwent restraint stress alone (P<0.05); this was associated with reduced macrophage infiltration and lower lipid concentrations in plaques. Sevoflurane reduced gene transcription and protein expression levels of pro-inflammatory cytokines (≥69-75%; P<0.05) and matrix metalloproteinases (≥39-65%; P<0.05) at both gene transcription and protein levels, compared with controls. Sevoflurane dose dependently increased Types I and III collagen deposition through enhanced protein expression of P4Hα1, both in vivo and in vitro (0.7-3.3-fold change; P<0.05).

CONCLUSIONS

Sevoflurane dose dependently promotes plaque stabilisation and decreases the incidence of plaque disruption in ApoE^-/- mice by increasing collagen deposition and inhibiting inflammation. These mechanisms may contribute to sevoflurane reducing MACCE.

The Impact of Anesthetic Regimen on Outcomes in Adult Cardiac Surgery: A Narrative Review

Despite improvements in surgical techniques and perioperative care, cardiac surgery still is burdened by relatively high mortality and frequent major postoperative complications, including myocardial dysfunction, pulmonary complications, neurologic injury, and acute kidney injury. Although the surgeon's skills and volume and patient- and procedure-related risk factors play a major role in the success of cardiac surgery, there is growing evidence that also optimizing perioperative care may improve outcomes significantly. The present review focuses on the aspects of perioperative care that are strictly related to the anesthesia regimen, with special reference to volatile anesthetics and neuraxial anesthesia, whose effect on outcome in adult cardiac surgery has been investigated extensively.

Current Practice of Calcium Use During Cardiopulmonary Bypass Weaning: Results of an International Survey

OBJECTIVES

To describe international practices on the use of calcium salts during cardiopulmonary bypass (CPB) weaning in adult cardiac surgery patients.

DESIGN

Multiple-choice survey on current practice of CPB weaning.

SETTING

Online survey using the SurveyMonkey platform.

PARTICIPANTS

Departments of cardiac anesthesiology worldwide.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Out of 112 surveys sent, 100 centers from 32 countries replied. The majority of centers (88 of 100 = 88%) administer calcium salts intraoperatively: 71 of 100 (71%) are using these drugs for CPB weaning and 78 of 100 (78%) for correction of hypocalcemia. Among the 88 centers that use calcium salts intraoperatively, 66% (58 of 88) of respondents use calcium chloride, 22% (19 of 88) use calcium gluconate, and 12% (11 of 88) use both drugs. Calcium salts are routinely used during normal (47 of 71 centers = 66%) and difficult (59 of 71 centers = 83%) weaning from CPB. Doses of 5 to 15 mg/kg during termination of CPB were used by 55 of 71 centers (77%) either by bolus (39 of 71, 55%) or over a time period longer than 1 minute (32 of 71 = 45%). Norepinephrine is the most commonly used first line vasopressor or inotropic agent used to support hemodynamics during termination of CPB in 32 out of 100 centers (32%), and calcium is the second one, used by 23 out of 100 centers (23%).

CONCLUSION

This survey demonstrates that the majority of cardiac centers use calcium in adult patients undergoing cardiac surgery, especially during weaning from CPB. There is variability on the type of drug, dose, and modality of drug administration.

Calcium Administration During Weaning From Cardiopulmonary Bypass: A Narrative Literature Review

The search for safe and effective patient management strategies during weaning from cardiopulmonary bypass is ongoing; intravenous calcium is occasionally used as a first-line drug. The physiologic role of calcium suggests that it can support the function of the cardiovascular system during this critical period. Patients may be mildly hypocalcemic after cardiopulmonary bypass; however, this degree of hypocalcemia does not significantly impair the cardiovascular system. The transient beneficial effects of calcium administration (increase in arterial blood pressure, systemic vascular resistance, cardiac index, stroke volume, and coronary perfusion pressure) might be helpful in cases of moderate contractility reduction or vasoplegia. Nonetheless, effects on clinically relevant endpoints are unknown, and possible systemic side effects, such as transient reduction in internal mammary artery graft flow, attenuation of the effects of β-sympathomimetics, "stone heart" phenomenon, and pancreatic cellular injury, may limit the use of calcium salts. Further studies are needed to expand the understanding of the effects of calcium administration on patient outcomes.

A Systematic Review and International Web-Based Survey of Randomized Controlled Trials in the Perioperative and Critical Care Setting: Interventions Increasing Mortality

OBJECTIVE

Reducing mortality is a key target in critical care and perioperative medicine. The authors aimed to identify all nonsurgical interventions (drugs, techniques, strategies) shown by randomized trials to increase mortality in these clinical settings.

DESIGN

A systematic review of the literature followed by a consensus-based voting process.

SETTING

A web-based international consensus conference.

PARTICIPANTS

Two hundred fifty-one physicians from 46 countries.

INTERVENTIONS

The authors performed a systematic literature search and identified all randomized controlled trials (RCTs) showing a significant increase in unadjusted landmark mortality among surgical or critically ill patients. The authors reviewed such studies during a meeting by a core group of experts. Studies selected after such review advanced to web-based voting by clinicians in relation to agreement, clinical practice, and willingness to include each intervention in international guidelines.

MEASUREMENTS AND MAIN RESULTS

The authors selected 12 RCTs dealing with 12 interventions increasing mortality: diaspirin-crosslinked hemoglobin (92% of agreement among web voters), overfeeding, nitric oxide synthase inhibitor in septic shock, human growth hormone, thyroxin in acute kidney injury, intravenous salbutamol in acute respiratory distress syndrome, plasma-derived protein C concentrate, aprotinin in high-risk cardiac surgery, cysteine prodrug, hypothermia in meningitis, methylprednisolone in traumatic brain injury, and albumin in traumatic brain injury (72% of agreement). Overall, a high consistency (ranging from 80% to 90%) between agreement and clinical practice was observed.

CONCLUSION

The authors identified 12 clinical interventions showing increased mortality supported by randomized controlled trials with nonconflicting evidence, and wide agreement upon clinicians on a global scale.