Inflammatory response and extracorporeal circulation. Best Pract Res Clin Anaesthesiol. 2015;29:113-123. [PMID: 26060024 DOI: 10.1016/j.bpa.2015.03.001]

The impact of cardiopulmonary bypass time on the Sequential Organ Failure Assessment score after cardiac surgery

OBJECTIVES

Postoperative organ dysfunction is common after cardiac surgery, particularly when cardiopulmonary bypass (CPB) is used. The Sequential Organ Failure Assessment (SOFA) score is validated to predict morbidity and mortality in cardiac surgery. However, the impact of CPB duration on postoperative SOFA remains unclear.

METHODS

This is a retrospective study. Categorical values are presented as percentages. The comparison of SOFA groups utilized the Kruskal-Wallis chi-squared test, complemented by ad hoc Dunn's test with Bonferroni correction. Multinomial logistics regressions were employed to evaluate the relationship between CPB time and SOFA.

RESULTS

A total of 1032 patients were included. CPB time was independently associated with higher postoperative SOFA scores at 24 h. CPB time was significantly higher in patients with SOFA 4-5 (**P = 0.0022) or higher (***P < 0.001) when compared to SOFA 0-1. The percentage of patients with no/mild dysfunction decreased with longer periods of CPB, down to 0% for CPB time >180min (50% of the patients with >180m in of CPB presented SOFA ≥ 10). The same trend is observed for each of the SOFA variables, with higher impact in the cardiovascular and renal systems. Severe dysfunction occurs especially >200 min of CPB (cardiovascular system >100 min; other systems mainly >200 min).

CONCLUSIONS

CPB time may predict the probability of postoperative SOFA categories. Patients with extended CPB durations exhibited higher SOFA scores (overall and for each variable) at 24 h, with higher proportion of moderate and severe dysfunction with increasing times of CPB.

Procalcitonin for the diagnosis of postoperative bacterial infection after adult cardiac surgery: a systematic review and meta-analysis

BACKGROUND AND AIMS

Patients undergoing cardiac surgery are subject to infectious complications that adversely affect outcomes. Rapid identification is essential for adequate treatment. Procalcitonin (PCT) is a noninvasive blood test that could serve this purpose, however its validity in the cardiac surgery population is still debated. We therefore performed a systematic review and meta-analysis to estimate the accuracy of PCT for the diagnosis of postoperative bacterial infection after cardiac surgery.

METHODS

We included studies on adult cardiac surgery patients, providing estimates of test accuracy. Search was performed on PubMed, EmBase and WebOfScience on April 12th, 2023 and rerun on September 15th, 2023, limited to the last 10 years. Study quality was assessed with the QUADAS-2 tool. The pooled measures of performance and diagnostic accuracy, and corresponding 95% Confidence Intervals (CI), were calculated using a bivariate regression model. Due to the variation in reported thresholds, we used a multiple-thresholds within a study random effects model for meta-analysis (diagmeta R-package).

RESULTS

Eleven studies were included in the systematic review, and 10 (2984 patients) in the meta-analysis. All studies were single-center with observational design, five of which with retrospective data collection. Quality assessment highlighted various issues, mainly concerning lack of prespecified thresholds for the index test in all studies. Results of bivariate model analysis using multiple thresholds within a study identified the optimal threshold at 3 ng/mL, with a mean sensitivity of 0.67 (0.47-0.82), mean specificity of 0.73 (95% CI 0.65-0.79), and AUC of 0.75 (IC95% 0.29-0.95). Given its importance for practice, we also evaluated PCT's predictive capability. We found that positive predictive value is at most close to 50%, also with a high prevalence (30%), and the negative predictive value was always > 90% when prevalence was < 20%.

CONCLUSIONS

These results suggest that PCT may be used to help rule out infection after cardiac surgery. The optimal threshold of 3 ng/mL identified in this work should be confirmed with large, well-designed randomized trials that evaluate the test's impact on health outcomes and on the use of antibiotic therapy. PROSPERO Registration number CRD42023415773. Registered 22 April 2023.

A novel model for predicting a composite outcome of major complications after valve surgery

Background

On-pump valve surgeries are associated with high morbidity and mortality. The present study aimed to reliably predict a composite outcome of postoperative complications using a minimum of easily accessible clinical parameters.

Methods

A total of 7,441 patients who underwent valve surgery were retrospectively analyzed. Data for 6,220 patients at West China Hospital of Sichuan University were used to develop a predictive model, which was validated using data from 1,221 patients at the Second Affiliated Hospital of Zhejiang University School of Medicine. The primary outcome was a composite of major complications: all-cause death in hospital, stroke, myocardial infarction, and severe acute kidney injury. The predictive model was constructed using the least absolute shrinkage and selection operator as well as multivariable logistic regression. The model was assessed in terms of the areas under receiver operating characteristic curves, calibration, and decision curve analysis.

Results

The primary outcome occurred in 129 patients (2.1%) in the development cohort and 71 (5.8%) in the validation cohort. Six variables were retained in the predictive model: New York Heart Association class, diabetes, glucose, blood urea nitrogen, operation time, and red blood cell transfusion during surgery. The C-statistics were 0.735 (95% CI, 0.686-0.784) in the development cohort and 0.761 (95% CI, 0.694-0.828) in the validation cohort. For both cohorts, calibration plots showed good agreement between predicted and actual observations, and ecision curve analysis showed clinical usefulness. In contrast, the well-established SinoSCORE did not accurately predict the primary outcome in either cohort.

Conclusions

This predictive nomogram based on six easily accessible variables may serve as an "early warning" system to identify patients at high risk of major complications after valve surgery.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT04476134].

Effect of High-Dose Selenium on Postoperative Organ Dysfunction and Mortality in Cardiac Surgery Patients: The SUSTAIN CSX Randomized Clinical Trial

Importance

Selenium contributes to antioxidative, anti-inflammatory, and immunomodulatory pathways, which may improve outcomes in patients at high risk of organ dysfunctions after cardiac surgery.

Objective

To assess the ability of high-dose intravenous sodium selenite treatment to reduce postoperative organ dysfunction and mortality in cardiac surgery patients.

Design, Setting, and Participants

This multicenter, randomized, double-blind, placebo-controlled trial took place at 23 sites in Germany and Canada from January 2015 to January 2021. Adult cardiac surgery patients with a European System for Cardiac Operative Risk Evaluation II score-predicted mortality of 5% or more or planned combined surgical procedures were randomized.

Interventions

Patients were randomly assigned (1:1) by a web-based system to receive either perioperative intravenous high-dose selenium supplementation of 2000 μg/L of sodium selenite prior to cardiopulmonary bypass, 2000 μg/L immediately postoperatively, and 1000 μg/L each day in intensive care for a maximum of 10 days or placebo.

Main Outcomes and Measures

The primary end point was a composite of the numbers of days alive and free from organ dysfunction during the first 30 days following cardiac surgery.

Results

A total of 1416 adult cardiac surgery patients were analyzed (mean [SD] age, 68.2 [10.4] years; 1043 [74.8%] male). The median (IQR) predicted 30-day mortality by European System for Cardiac Operative Risk Evaluation II score was 8.7% (5.6%-14.9%), and most patients had combined coronary revascularization and valvular procedures. Selenium did not increase the number of persistent organ dysfunction-free and alive days over the first 30 postoperative days (median [IQR], 29 [28-30] vs 29 [28-30]; P = .45). The 30-day mortality rates were 4.2% in the selenium and 5.0% in the placebo group (odds ratio, 0.82; 95% CI, 0.50-1.36; P = .44). Safety outcomes did not differ between the groups.

Conclusions and Relevance

In high-risk cardiac surgery patients, perioperative administration of high-dose intravenous sodium selenite did not reduce morbidity or mortality. The present data do not support the routine perioperative use of selenium for patients undergoing cardiac surgery.

Trial Registration

ClinicalTrials.gov Identifier: NCT02002247.

Influence of cardioplegic solution on incidence of delirium after CABG surgery: Use of Calafiore blood cardioplegia versus HTK - Bretschneider - solution in a single-center retrospective analysis from 2017 to 2021

BACKGROUND

Purpose of the present study is an evaluation of postoperative incidence for delirium after coronary artery bypass surgery (CABG). Study addressed whether application of Histidine-Tryptophan-Ketoglutarate (HTK) solution (Bretschneider) or blood cardioplegia (Calafiore) is associated with increased of postoperative delirium cases.

MATERIALS AND METHODS

In a retrospective, single center evaluation a total number of 273 patients were enrolled in the study from January 2017 to October 2021. There were 124 patients assigned to the Calafiore group blood cardioplegic solution (BCC) and 149 patients were included in the Bretschneider group (HTK). The primary endpoint was the postoperative delirium rate in its frequency of occurrence. Definition of the dilirium status was performed using the Confusion Assessment Method in the Intensive Care Unit (CAM-ICU) score during the first three postoperative days. Secondary endpoints were the time intervals of intensive care duration of stay, mechanical ventilation, total extracorporeal circulation, ischemia and reperfusion. Serum levels of the electrolytes Sodium, Potassium, ionized Calcium, and Chloride were monitored.

RESULTS

Although no significant difference in delirium status between the groups were noticed, on third postoperative day, delirium rate dependent on cardioplegia solution used (HTK 12.0%; BCC 3.0%; p = .024) and duration of intensive care stay differed (HTK 4.5 vs. BCC 3.0 days; p = .001). Although Ischemic time (HTK 73.0 vs. BCC 83.0 min; p < .001) and reperfusion time (HTK 35.0 vs. Calafiore 24.0 min; p < .001) were extended in the BCC group less cases of delirium were diagnosed. Serum sodium levels after HTK cardioplegic infusion were decreased (HTK 129.68 vs. BCC 138.96 mmol/l; p < .001). The significant difference persists up to the hundredth extracorporeal circulation circuit min (p = .005).

CONCLUSION

The present data suggest an impact of the cardioplegic solution used upon postoperative delirium rates. Optimization of cardiac arrest protocols is needed. Present data encourage further prospective studies regarding the impact of cardioplegic solutions on electrolyte imbalance for postoperative delirium rates in CABG surgery.

Anti-inflammatory effect of tranexamic acid on adult cardiac surgical patients: A PRISMA-compliant systematic review and meta-analysis

Objective

This study aims to evaluate the anti-inflammatory effect of tranexamic acid (TXA) on adult cardiac surgical patients.

Methods

PubMed, Embase, Ovid, Web of Science, CNKI, VIP, and WANFANG databases were systematically searched using the related keywords for cardiac surgical randomized controlled trials (RCTs) published from their inception to February 1, 2022. The primary outcomes were postoperative inflammatory biomarkers levels. The secondary outcomes were postoperative systemic inflammatory response syndrome and other major postoperative outcomes. The odds ratios and/or the weighted mean difference (WMD) with a 95% confidence interval (CI) were used to pool the data.

Results

Ten RCTs with 770 adult cardiac surgical patients were included. Compared with placebo, TXA achieved statistically significant inhibition of the postoperative interleukin (IL)-6 level (postoperative 6 h: n = 6 trials; WMD -31.66; 95% CI: -45.90, -17.42; p < 0.0001; I ²= 93%; postoperative 24 h: n =  8 trials; WMD, -44.06; 95% CI: -69.21, -18.91; p = 0.006; I ²= 100%); IL-8 level postoperative 24 h, TNF-α level postoperative 24 h, NE level postoperative 6 h: n = 3 trials; WMD, -36.83; 95% CI: -68.84, -4.83; p = 0.02; I ²= 95%); tissue necrosis factor alpha (TNF-α) level (postoperative 6 h: n = 3 trials; WMD, -7.21; 95% CI: -12.41, -2.01; p = 0.007; I ²= 47%; postoperative 24 h: n = 5 trials; WMD, -10.02; 95% CI: -14.93, -5.12; p < 0.0001; I ²= 94%); and neutrophil elastase (NE) level (postoperative 6 h: n = 3 trials; WMD, -66.93; 95% CI: -111.94, -21.92; p = 0.004; I ²= 86%). However, TXA achieved no statistically significant influence on the postoperative 24 h NE level.

Conclusions

TXA had a significant anti-inflammatory effect in adult cardiac surgical patients, as evidenced by the reduction of multiple postoperative proinflammatory biomarkers levels, but these results should be interpreted carefully and cautiously, as only a limited number of studies were included and there was high heterogeneity between them.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/#recordDetails, identifier: CRD42022312919.

Anticoagulation Strategies during Extracorporeal Membrane Oxygenation: A Narrative Review

The development of extracorporeal life support technology has added a new dimension to the care of critically ill patients who fail conventional treatment options. Extracorporeal membrane oxygenation (ECMO)—specialized temporary life support for patients with severe cardiac or pulmonary failure—plays a role in bridging the time for organ recovery, transplant, or permanent assistance. The overall patient outcome is dependent on the underlying disease, comorbidities, patient reaction to critical illness, and potential adverse events during ECMO. Moreover, the contact of the blood with the large artificial surface of an extracorporeal system circuit triggers complex inflammatory and coagulation responses. These processes may further lead to endothelial injury and disrupted microcirculation with consequent end-organ dysfunction and the development of adverse events like thromboembolism. Therefore, systemic anticoagulation is considered crucial to alleviate the risk of thrombosis and failure of ECMO circuit components. The gold standard and most used anticoagulant during extracorporeal life support is unfractionated heparin, with all its benefits and disadvantages. However, therapeutic anticoagulation of a critically ill patient carries the risk of clinically relevant bleeding with the potential for permanent injury or death. Similarly, thrombotic events may occur. Therefore, different anticoagulation strategies are employed, while the monitoring and the balance of procoagulant and anticoagulatory factors is of immense importance. This narrative review summarizes the most recent considerations on anticoagulation during ECMO support, with a special focus on anticoagulation monitoring and future directions.

The Influence of Multivessel Bypass Surgery on the Onset of Atrial Fibrillation in Elderly Patients

Aim. To study the factors associated with the development of postoperative atrial fibrillation (POAF) with single- or two- or more vascular bypass grafting in elderly patients with coronary heart disease.Methods. The study included 454 patients with coronary artery disease who underwent CABG. Patients were divided into 4 groups: 1 group – with single-vessel bypass, 2 group – with 2-vessels, 3 group – with 3-vessels and 4 group with 4-vessels bypass. During the observation period postoperative atrial fibrillation (POAF) occurred in 7.5% of patients in group 1, 18.4% in group 2, 17.5% in group 3 and 19.2% of patients in group 4. Since there were no significant differences in the incidence of POAF in patients with 2-4-vessels bypass grafting, these groups were combined for further analysis. 2 groups are allocated: Group I comprised patients with single-vessel bypass graft (79 patients, 76.0% of males, the average age of 65.0 [63.0;68.0] years), Group II – with 2-4-vessels bypass grafts (357 patients, 78.4% of males, the median age of 67.5 [64.5;69.0] years).Results. POAF occurred in 7.5% of patients in group I and in 18.4% of patients in group II (p=0.03) on the median 4.9 [1.2;8.7] day after coronary artery bypass graft. The multivariate regression analysis showed that indicators, associated with POAF development in patients undergoing CABG were the following: aortic cross-clamping time >36 min (odds ratio [OR)]1.4; 95% confidence interval (CI) 1.1-2.8; p=0.030), time of ischemia >19 min (OR 1.7; 95% CI 1.2-3.3; p=0.020), age >65 years (OR 1.8; 95% CI 1,1-4,1; p=0.010), left atrium diameter >39 mm (OR 2.9; 95% CI 1.5-5.4; p=0.005), left ventricular ejection fraction <51% (OR 1.9; 95% CI 1.2-3.0; p=0.04).Conclusion. In our study, atrial fibrillation in the early postoperative period was more common in patients undergoing multivessel coronary bypass surgery. Indicators, significantly associated with POAF in patients undergoing Coronary artery bypass graft were aortic cross-clamping time >36 minutes, time of ischemia >19 minutes, age >65 years, left atrium diameter >39 mm and left ventricular ejection fraction <51%.

Inflammation and Oxidative Stress in the Context of Extracorporeal Cardiac and Pulmonary Support

Extracorporeal circulation (ECC) systems, including cardiopulmonary bypass, and extracorporeal membrane oxygenation have been an irreplaceable part of the cardiothoracic surgeries, and treatment of critically ill patients with respiratory and/or cardiac failure for more than half a century. During the recent decades, the concept of extracorporeal circulation has been extended to isolated machine perfusion of the donor organ including thoracic organs (ex-situ organ perfusion, ESOP) as a method for dynamic, semi-physiologic preservation, and potential improvement of the donor organs. The extracorporeal life support systems (ECLS) have been lifesaving and facilitating complex cardiothoracic surgeries, and the ESOP technology has the potential to increase the number of the transplantable donor organs, and to improve the outcomes of transplantation. However, these artificial circulation systems in general have been associated with activation of the inflammatory and oxidative stress responses in patients and/or in the exposed tissues and organs. The activation of these responses can negatively affect patient outcomes in ECLS, and may as well jeopardize the reliability of the organ viability assessment, and the outcomes of thoracic organ preservation and transplantation in ESOP. Both ECLS and ESOP consist of artificial circuit materials and components, which play a key role in the induction of these responses. However, while ECLS can lead to systemic inflammatory and oxidative stress responses negatively affecting various organs/systems of the body, in ESOP, the absence of the organs that play an important role in oxidant scavenging/antioxidative replenishment of the body, such as liver, may make the perfused organ more susceptible to inflammation and oxidative stress during extracorporeal circulation. In the present manuscript, we will review the activation of the inflammatory and oxidative stress responses during ECLP and ESOP, mechanisms involved, clinical implications, and the interventions for attenuating these responses in ECC.

The role of antibody responses against glycans in bioprosthetic heart valve calcification and deterioration

Bioprosthetic heart valves (BHVs) are commonly used to replace severely diseased heart valves but their susceptibility to structural valve degeneration (SVD) limits their use in young patients. We hypothesized that antibodies against immunogenic glycans present on BHVs, particularly antibodies against the xenoantigens galactose-α1,3-galactose (αGal) and N-glycolylneuraminic acid (Neu5Gc), could mediate their deterioration through calcification. We established a large longitudinal prospective international cohort of patients (n = 1668, 34 ± 43 months of follow-up (0.1–182); 4,998 blood samples) to investigate the hemodynamics and immune responses associated with BHVs up to 15 years after aortic valve replacement. Early signs of SVD appeared in <5% of BHV recipients within 2 years. The levels of both anti-αGal and anti-Neu5Gc IgGs significantly increased one month after BHV implantation. The levels of these IgGs declined thereafter but anti-αGal IgG levels declined significantly faster in control patients compared to BHV recipients. Neu5Gc, anti-Neu5Gc IgG and complement deposition were found in calcified BHVs at much higher levels than in calcified native aortic valves. Moreover, in mice, anti-Neu5Gc antibodies were unable to promote calcium deposition on subcutaneously implanted BHV tissue engineered to lack αGal and Neu5Gc antigens. These results indicate that BHVs manufactured using donor tissues deficient in αGal and Neu5Gc could be less prone to immune-mediated deterioration and have improved durability.

In a large cohort of patients who underwent aortic valve replacement, antibody responses to glycans present in bioprosthetic heart valves, notably galactose-α1,3-galactose and N-glycolylneuraminic acid, were implicated in valve calcification and deterioration.

Impact of Immunonutrition on T Cell Activation: A Randomized Control Study in Cardiac Surgery Patients

Background.

Cardiac surgery provokes an intense inflammatory response that can cause an immunosuppressive state and adverse postoperative outcomes. We recently showed that postoperative immunonutrition with glutamine in “fragile” low-risk cardiac surgery patients was associated with a significantly increased level of CD3+ and CD4+ T cells. In order to clarify the biological relevance and clinical importance of these findings, we investigated whether an increase in the CD4+ T cell level was caused by changes in the systemic inflammatory response (caused by surgery or infection) and if it was associated with their activation status.

Methods.

A randomized control study of low operative risk but “fragile” cardiac surgery patients was performed. Patients were randomized into immunonutrition (IN) and control groups (C). The IN group received normal daily meals plus special immune nutrients for 5 days postoperatively, while the C group received only normal daily meals. Laboratory parameters were investigated before surgery and on the sixth postoperative day and the groups were compared accordingly. The expression of the CD69+ marker was investigated to determine T cell activation status. Serum concentrations of cytokines (interleukin-10 (IL-10), tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6)) and C-reactive protein (CRP) were determined to assess the systemic inflammatory response, while procalcitonin (PCT) levels were evaluated to confirm or deny possible bacterial infection.

Results.

Fifty-five patients were enrolled in the study. Twenty-seven (49.1%) were randomized in the IN group. Results show that on the sixth postoperative day, the CD4+CD69+ and CD8+CD69+ counts did not differ between the IN and C groups, accordingly 0.25 [0.16–0.50] vs 0.22 [0.13-0.41], p=0.578 and 0.13 [0.06–0.3] vs 0.09 [0.05–0.14], p=0.178. Also, statistically significant differences were not observed in the cytokine levels (IN and C groups: TNF-α 8.13 [7.32–10.31] vs 8.78 [7.65–11.2], p=0.300; IL-6 14.65 [9.28–18.95] vs 12.25 [8.55–22.50], p=0.786; IL-10 5.0 [5.0–5.0] vs 5.0 [5.0–5.0], p=0.343 respectively), which imply that an elevated T cell count is not associated with the systemic inflammatory response. Also, PCT (IN and C groups: 0.03 [0.01–0.09] vs 0.05 [0.03–0.08], p=0.352) and CRP (IN and C groups 62.7 [34.2–106.0] vs 63.7 [32.9–91.0], p=0.840) levels did not differ between the two groups. Moreover, low levels of PCT indicated that the increase in T cell count was not determined by bacterial infection.

Conclusions.

Our findings showed that CD4+ T cell levels were associated with neither the systemic inflammatory response nor bacterial infection. Secondly, increases in T cells are not accompanied by their activation status. These results suggest a hypothesis that a higher postoperative T cell concentration may be associated with postoperative immunonutrition in low-risk cardiac surgery patients with intact cellular vitality, i.e. “fragile”. However, immunonutrition alone did not affect T cell activation status.

Dynamics of Vascular Protective and Immune Supportive Sphingosine-1-Phosphate During Cardiac Surgery

Introduction

Sphingosine-1-phosphate (S1P) is a signaling lipid and crucial in vascular protection and immune response. S1P mediated processes involve regulation of the endothelial barrier, blood pressure and S1P is the only known inducer of lymphocyte migration. Low levels of circulatory S1P correlate with severe systemic inflammatory syndromes such as sepsis and shock states, which are associated with endothelial barrier breakdown and immunosuppression. We investigated whether S1P levels are affected by sterile inflammation induced by cardiac surgery.

Materials and Methods

In this prospective observational study we included 46 cardiac surgery patients, with cardiopulmonary bypass (CPB, n=31) and without CPB (off-pump, n=15). Serum-S1P, S1P-sources and carriers, von-Willebrand factor (vWF), C-reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6) were measured at baseline, post-surgery and at day 1 (POD 1) and day 4 (POD 4) after surgical stimulus.

Results

Median S1P levels at baseline were 0.77 nmol/mL (IQR 0.61-0.99) and dropped significantly post-surgery. S1P was lowest post-surgery with median levels of 0.37 nmol/mL (IQR 0.31-0.47) after CPB and 0.46 nmol/mL (IQR 0.36-0.51) after off-pump procedures (P<0.001). The decrease of S1P was independent of surgical technique and observed in all individuals. In patients, in which S1P levels did not recover to preoperative baseline ICU stay was longer and postoperative inflammation was more severe. S1P levels are associated with its sources and carriers and vWF, as a more specific endothelial injury marker, in different phases of the postoperative course. Determination of S1P levels during surgery suggested that also the anticoagulative effect of heparin might influence systemic S1P.

Discussion

In summary, serum-S1P levels are disrupted by major cardiac surgery. Low S1P levels post-surgery may play a role as a new marker for severity of cardiac surgery induced inflammation. Due to well-known protective effects of S1P, low S1P levels may further contribute to the observed prolonged ICU stay and worse clinical status. Moreover, we cannot exclude a potential inhibitory effect on circulating S1P levels by heparin anticoagulation during surgery, which would be a new pro-inflammatory pleiotropic effect of high dose heparin in patients undergoing cardiac surgery.

Postoperative Neutrophil-to-Lymphocyte Ratio Is Associated with Mortality in Adult Patients After Cardiopulmonary Bypass Surgery: A Cohort Study

Background

Cardiopulmonary bypass (CPB) contributes to the development of systemic inflammatory response after cardiothoracic surgery. As a measure of inflammation and immune reaction, the neutrophil-to-lymphocyte ratio (NLR) has been linked to poor outcomes in a variety of diseases. However, it remains to be seen whether postoperative NLR is associated with CPB patient mortality. The purpose of this research was to explore the prognostic role of the postoperative NLR in adult patients undergoing cardiothoracic surgery with cardiopulmonary bypass.

Material/Methods

This study incorporates data from the MIMIC III database, which includes more than 50 000 critically ill patients. The variable of interest was postoperative NLR. The primary outcome was 30-day mortality and the secondary outcomes were 90-day mortality, length of intensive care unit stay, and length of hospital stay.

Results

We enrolled 575 CPB patients. The ROC curve for the postoperative NLR to estimate mortality was 0.741 (95% confidence interval [CI]: 0.636–0.847, P<0.001), and the critical value was 7.48. There was a significant difference between different postoperative NLR levels in the Kaplan-Meier curve (P=0.045). Furthermore, elevated postoperative NLR was associated with increased hospital mortality (hazard ratio [HR]: 1.1, 95% CI: 1.0–1.1, P=0.021). However, there was no important relationship in these patients between the postoperative NLR levels and 90-day mortality (HR: 1.1, 95% CI: 1.0–1.5, P=0.465).

Conclusions

Our findings suggest that higher postoperative NLR is associated with greater hospital mortality in adult patients undergoing cardiopulmonary bypass surgery.

Elevated Systemic and Intestinal Inflammatory Response Are Associated With Gut Microbiome Disorder After Cardiovascular Surgery

Systemic inflammatory response after cardiovascular surgery is associated with poor prognosis, to which gut barrier impairment is related. To investigate whether perioperative changes of the gut microbiome are associated with systemic and intestinal inflammatory response, we examined changes of the gut microbiome, intestinal homeostasis, and systemic inflammatory response in cardiovascular patients before (Pre) surgery and on the first defecation day [postoperative time 1 (Po1)] or a week [postoperative time 2 (Po2)] postsurgery. Markedly, the enhanced systemic inflammatory response was observed in Po1 and Po2 compared with that in Pre. In line with inflammatory response, impaired gut barrier and elevated gut local inflammation were observed in Po1 and Po2. Microbiome analysis showed a remarkable and steady decline of alpha diversity perioperatively. In addition, microbial composition in the postoperation period was characterized by significant expansion of Enterococcus along with a decrease in anaerobes (Blautia, Faecalibacterium, Bifidobacterium, Roseburia, Gemmiger, [Ruminococcus], and Coprococcus), which were typically health-associated bacteria. Spearman correlation analysis showed microbiome disorder was associated with enhanced systemic inflammatory response and intestinal dysbiosis. These results suggest that microbiome disorder was related to disturbed gut homeostatic and subsequently elevates plasma endotoxin and systemic inflammatory response after cardiovascular surgery. This study not only highlights gut microbiome would be considered in future clinical practice but also proposes a promising perspective of potential diagnostic and therapeutic options for perioperative management of cardiovascular surgery patients.

Arterial lactate levels and their prognostic value in patients undergoing pulmonary thromboendarterectomy

Objective

Evaluate the change of lactate levels and its prognostic role in the postoperative period of patients undergoing pulmonary thromboendarterectomy.

Methods

Retrospective study between 2001 and 2019. Patients older than 18 years and who underwent pulmonary thromboendarterectomy were included. The U Mann Whitney test was performed to evaluate the change between lactate levels, and Cox regression analysis to evaluate the relationship with mortality. Areas under the curve were constructed for lactate levels.

Results

Seventy-three patients were operated on during the study period. Median age was 51 years, 55% female. The median lactate on days 1 was 4.65 mml/L and on day 2 it was 1.62 mml/L with a change of 2.87 mml/L. No differences were found between the levels measured on day 1 and 2 between the people who died and those who did not on day 30. In the multivariate regression of COX, no relationship with mortality was found. The area under the curve shows regular performance on both day 1 and day 2 in predicting mortality outcomes.

Conclusions

The behavior of the lactate in patients undergoing pulmonary thromboendarterectomy shows a rapid change during the first hours after the procedure. No role was found as a predictor of mortality neither in-hospital nor in follow-up.

Fluid management: An update for perioperative practitioners

An interprofessional team approach is required to achieve optimum fluid balance for patients during the perioperative period. Incorrect management of fluid assessment and monitoring is associated with adverse outcomes. The scientific understanding of perioperative fluid balance has improved over recent years leading to changes in clinical practice with regard to volume and choice of intravenous fluid. It is important that perioperative practitioners have an understanding of intravenous fluid, fluid compartmentalisation, fluid mechanics and intravascular fluid control mechanisms. Optimum fluid status not only shortens hospital stay but also reduces the incidence of postoperative nausea and vomiting and complication profiles. This article aims to provide perioperative practitioners with a comprehensive overview of fluid management. It will cover important issues surrounding physiological control of fluid balance, choice of intravenous fluid therapy, methods to monitor intravascular volume and factors which influence delivery.

Case Report: Emergency CABG Following Failure of PTCA in a COVID-19 Patient

The coronavirus disease 2019 (COVID-19) pandemic outbreak, caused by severe acute respiratory syndrome coronavirus-2 (SARS-Cov-2) is affecting people worldwide representing a public health emergency. The effect of concomitant COVID-19 on patients who underwent cardiac surgery using cardiopulmonary bypass (CPB) is still undefined. Both SARS-Cov-2 infection and CPB can develop a cytokines storm and haemostatic disarrangements leading to acute respiratory distress syndrome (ARDS) and post-perfusion lung syndrome, respectively. SARS-Cov-2 infection may trigger and exacerbate post-inflammatory state after CPB resulting in higher risk of post-surgical adverse outcomes. International guidelines lack to provide standard management protocols for pre-operative COVID-19 patients requiring non-deferrable cardiac surgery intervention. We present a report of a successful coronary artery bypass grafting (CABG) emergency operation in a COVID-19 patient, who presented unstable angina and coronary artery dissection during cardiac catheterization and percutaneous transluminal coronary angioplasty (PTCA).

Effects of Balanced Ultrafiltration During Extracorporeal Circulation for Children with Congenital Heart Disease on Postoperative Serum Inflammatory Response

Objectives: We studied inflammatory marker changes with ultrafiltration extracorporeal techniques and compared these levels to those occurring during conventional techniques. Methods: Seventy-four children undergoing extracorporeal circulation during congenital heart surgery were divided into two groups-conventional (control) and balanced ultrafiltrations (study). Serum interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and soluble intercellular adhesion molecule-1 (sICAM-1), static lung compliance (Cstat), alveolar-arterial oxygen partial pressure difference (A-aDO2), and oxygenation index (OI) were measured. Results: Thirty minutes after extracorporeal circulation (T1), IL-6 and TNF-α levels significantly increased (p < .05), which plummeted 3 h after surgery (T2). The levels in the study group were lower (p < .05). sICAM-1 levels at T1 and T2 significantly exceeded those at T0, and study group had lower levels (p < .05). At T1, Cstat and OI dropped (p < .05), which increased at T2 (p < .05), and study group had less decreases (p < .05). A-aDO2 at T1 surpassed that before intervention (p < .05), and study group had less increase (p < .05). Conclusion: Balanced ultrafiltration exerts protective effects on children with congenital heart disease undergoing extracorporeal circulation.

A novel technique for laser-assisted revascularization: an in vitro pilot study

The common limitation of surgical revascularization procedures for severe tissue ischemia due to cardiovascular diseases is the need to interrupt blood flow during the intervention. We aim to introduce a new technique that allows a sutureless, non-occlusive revascularization. A 3-step technique was developed using rabbit's aorta to simulate a side-to-side anastomosis model. It enables the creation of a bypass circuit for revascularization. The first step was the soldering of 2 vessels in a side-to-side fashion based on the laser-assisted vascular anastomosis (LAVA) principle using a diode laser emitting irradiation at 810 nm with an albumin-based solder patch between them, followed by the creation of a channel within the patch using either a holmium-doped yttrium aluminum garnet laser (Ho:YAG) at λ = 2100 nm or a xenon-chloride excimer laser (XeCl) at λ = 308 nm. Thereby, a bypass circuit was created, thus allowing a non-ischemic revascularization. The system was deemed functional when a flow was observed across the anastomosis. The highest average tensile strength recorded after side-to-side LAVA using a diode laser power of 3.2 W for 60 s was 2278.6 ± 800 mN (n = 20). The Ho:YAG laser created the channels with less tension on the anastomosis than the excimer laser. Histological analysis showed limited thermal damage and good patch-tissue adaptation. The preliminary results of this feasibility study outline the foundations for an entirely sutureless laser-assisted revascularization procedure. The next studies will evaluate the rheological parameters across the bypass circuit to optimize the post-anastomotic flow.

Sonographic muscle mass assessment in patients after cardiac surgery

BACKGROUND

Patients undergoing cardiac surgery particularly those with comorbidities and frailty, experience frequently higher rates of post-operative morbidity, mortality and prolonged hospital length of stay. Muscle mass wasting seems to play important role in prolonged mechanical ventilation (MV) and consequently in intensive care unit (ICU) and hospital stay.

AIM

To investigate the clinical value of skeletal muscle mass assessed by ultrasound early after cardiac surgery in terms of duration of MV and ICU length of stay.

METHODS

In this observational study, we enrolled consecutively all patients, following their admission in the Cardiac Surgery ICU within 24 h of cardiac surgery. Bedside ultrasound scans, for the assessment of quadriceps muscle thickness, were performed at baseline and every 48 h for seven days or until ICU discharge. Muscle strength was also evaluated in parallel, using the Medical Research Council (MRC) scale.

RESULTS

Of the total 221 patients enrolled, ultrasound scans and muscle strength assessment were finally performed in 165 patients (patients excluded if ICU stay < 24 h). The muscle thickness of rectus femoris (RF), was slightly decreased by 2.2% [(95% confidence interval (CI): - 0.21 to 0.15), n = 9; P = 0.729] and the combined muscle thickness of the vastus intermedius (VI) and RF decreased by 3.5% [(95%CI: - 0.4 to 0.22), n = 9; P = 0.530]. Patients whose combined VI and RF muscle thickness was below the recorded median values (2.5 cm) on day 1 (n = 80), stayed longer in the ICU (47 ± 74 h vs 28 ± 45 h, P = 0.02) and remained mechanically ventilated more (17 ± 9 h vs 14 ± 9 h, P = 0.05). Moreover, patients with MRC score ≤ 48 on day 3 (n = 7), required prolonged MV support compared to patients with MRC score ≥ 49 (n = 33), (44 ± 14 h vs 19 ± 9 h, P = 0.006) and had a longer duration of extracorporeal circulation was (159 ± 91 min vs 112 ± 71 min, P = 0.025).

CONCLUSION

Skeletal quadriceps muscle thickness assessed by ultrasound shows a trend to a decrease in patients after cardiac surgery post-ICU admission and is associated with prolonged duration of MV and ICU length of stay.

A Novel C1-Esterase Inhibitor Oxygenator Coating Prevents FXII Activation in Human Blood

The limited hemocompatibility of currently used oxygenator membranes prevents long-term use of artificial lungs in patients with lung failure. To improve hemocompatibility, we developed a novel covalent C1-esterase inhibitor (C1-INH) coating. Besides complement inhibition, C1-INH also prevents FXII activation, a very early event of contact phase activation at the crossroads of coagulation and inflammation. Covalently coated heparin, as the current anticoagulation gold standard, served as control. Additionally, a combination of both coatings (C1-INH/heparin) was established. The coatings were tested for their hemocompatibility by dynamic incubation with freshly drawn human whole blood. The analysis of various blood and plasma parameters revealed that C1-INH-containing coatings were able to markedly reduce FXIIa activity compared to heparin coating. Combined C1-INH/heparin coatings yielded similarly low levels of thrombin-antithrombin III complex formation as heparin coating. In particular, adhesion of monocytes and platelets as well as the diminished formation of fibrin networks were observed for combined coatings. We could show for the first time that a covalent coating with complement inhibitor C1-INH was able to ameliorate hemocompatibility. Thus, the early inhibition of the coagulation cascade is likely to have far-reaching consequences for the other cross-reacting plasma protein pathways.

Biomaterials to Prevent Post-Operative Adhesion

Surgery is performed to treat various diseases. During the process, the surgical site is healed through self-healing after surgery. Post-operative or tissue adhesion caused by unnecessary contact with the surgical site occurs during the normal healing process. In addition, it has been frequently found in patients who have undergone surgery, and severe adhesion can cause chronic pain and various complications. Therefore, anti-adhesion barriers have been developed using multiple biomaterials to prevent post-operative adhesion. Typically, anti-adhesion barriers are manufactured and sold in numerous forms, such as gels, solutions, and films, but there are no products that can completely prevent post-operative adhesion. These products are generally applied over the surgical site to physically block adhesion to other sites (organs). Many studies have recently been conducted to increase the anti-adhesion effects through various strategies. This article reviews recent research trends in anti-adhesion barriers.

Will high-dose heparin affect blood loss and inflammatory response in patients undergoing cardiopulmonary bypass?

INTRODUCTION

We performed a randomized study to investigate if a high versus a standard dose of heparin dose during cardiopulmonary bypass could affect intra- and post-operative bleeding and reduce the inflammatory response.

METHODS

A total of 30 patients undergoing elective coronary artery bypass grafting were randomized into high or standard dose of heparin during cardiopulmonary bypass. Blood loss was documented peri- and post-operatively, and interleukin-6, tumor necrosis factor-α, and C3 were measured in conjunction with cardiopulmonary bypass.

RESULTS

Data from 29 patients were analyzed after exclusion of one patient. The mean initial bolus and total heparin doses were 43,000 ± 5,800 IU versus 35,000 ± 4,100 IU, (p < 0.001), and 58,000 ± 9,500 IU versus 45,000 ± 7,900 IU, (p < 0.001) in the intervention and the control group, respectively. The median intra-operative bleeding was 150 mL (interquartile range 100-325) in the control versus 225 mL (IQR 200-350) in the intervention group, p = 0.15. The median chest tube blood loss 12 hour post-operatively was 300 mL (interquartile range 250-385) in the control versus 450 mL (IQR 315-505) in the intervention group, p = 0.029. There was no significant difference between the control group and the intervention group during cardiopulmonary bypass for the measured inflammatory markers interleukin-6 (p = 0.98), tumor necrosis factor-α (p = 0.72), or C3 (p = 0.13).

CONCLUSION

This small study showed a small increase of post-operative bleeding associated with higher heparin dosage in conjunction with cardiopulmonary bypass but did not demonstrate an effect of heparin on the inflammatory response to cardiopulmonary bypass.

Pulmonary complications associated with veno-arterial extra-corporeal membrane oxygenation: a comprehensive review

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a life-saving technology that provides transient respiratory and circulatory support for patients with profound cardiogenic shock or refractory cardiac arrest. Among its potential complications, VA-ECMO may adversely affect lung function through various pathophysiological mechanisms. The interaction of blood components with the biomaterials of the extracorporeal membrane elicits a systemic inflammatory response which may increase pulmonary vascular permeability and promote the sequestration of polymorphonuclear neutrophils within the lung parenchyma. Also, VA-ECMO increases the afterload of the left ventricle (LV) through reverse flow within the thoracic aorta, resulting in increased LV filling pressure and pulmonary congestion. Furthermore, VA-ECMO may result in long-standing pulmonary hypoxia, due to partial shunting of the pulmonary circulation and to reduced pulsatile blood flow within the bronchial circulation. Ultimately, these different abnormalities may result in a state of persisting lung inflammation and fibrotic changes with concomitant functional impairment, which may compromise weaning from VA-ECMO and could possibly result in long-term lung dysfunction. This review presents the mechanisms of lung damage and dysfunction under VA-ECMO and discusses potential strategies to prevent and treat such alterations.

Compared with matched controls, patients with postoperative atrial fibrillation (POAF) have increased long-term AF after CABG, and POAF is further associated with increased ischemic stroke, heart failure and mortality even after adjustment for AF

Objective

To analyze (1) associations between postoperative atrial fibrillation (POAF) after CABG and long-term cardiovascular outcome, (2) whether associations were influenced by AF during follow-up, and (3) if morbidities associated with POAF contribute to mortality.

Methods

An observational cohort study of 7145 in-hospital survivors after isolated CABG (1996–2012), with preoperative sinus rhythm and without AF history. Incidence of AF was compared with matched controls. Time-updated covariates were used to adjust for POAF-related morbidities during follow-up, including AF.

Results

Thirty-one percent of patients developed POAF. Median follow-up was 9.8 years. POAF patients had increased AF compared with matched controls (HR 3.03; 95% CI 2.66–3.49), while AF occurrence in non-POAF patients was similar to controls (1.00; 0.89–1.13). The observed AF increase among POAF patients compared with controls persisted over time (> 10 years 2.73; 2.13–3.51). Conversely, the non-POAF cohort showed no AF increase beyond the first postoperative year. Further, POAF was associated with long-term AF (adjusted HR 3.20; 95% CI 2.73–3.76), ischemic stroke (1.23; 1.06–1.42), heart failure (1.44; 1.27–1.63), overall mortality (1.21; 1.11–1.32), cardiac mortality (1.35; 1.18–1.54), and cerebrovascular mortality (1.54; 1.17–2.02). These associations remained after adjustment for AF during follow-up. Adjustment for other POAF-associated morbidities weakened the association between POAF and overall mortality, which became non-significant.

Conclusions

Patients with POAF after CABG had three times the incidence of long-term AF compared with both non-POAF patients and matched controls. POAF was associated with long-term ischemic stroke, heart failure, and corresponding mortality even after adjustment for AF during follow-up. The increased overall mortality was partly explained by morbidities associated with POAF.

Graphic abstract

Electronic supplementary material

The online version of this article (10.1007/s00392-020-01614-z) contains supplementary material, which is available to authorized users.

A case series on the value of tau and neurofilament protein levels to predict and detect delirium in cardiac surgery patients

BACKGROUND

Delirium following cardiac surgery is a relevant complication in the majority of elderly patients but its prediction is challenging. Cardiopulmonary bypass, essential for many interventions in cardiac surgery, is responsible for a severe inflammatory response leading to neuroinflammation and subsequent delirium. Neurofilament light protein (NfL) and tau protein (tau) are specific biomarkers to detect neuroaxonal injury as well as glial fibrillary acidic protein (GFAP), a marker of astrocytic activation.

METHODS

We thought to examine the perioperative course of these markers in a case series of each three cardiac surgery patients under off-pump cardiac arterial bypass without evolving delirium (OPCAB-NDEL), patients with a procedure under cardio-pulmonary bypass (CPB) without delirium (CPB-NDEL) and delirium after a CPB procedure (CPB-DEL). Delirium was diagnosed by the Confusion Assessment Method for the ICU and chart reviews.

RESULTS

We observed increased preoperative levels of tau in patients with later delirium, whereas values of NfL and GFAP did not differ. In the postoperative course, all biomarkers increased multi-fold. NfL levels sharply increased in patients with CPB reaching the highest levels in the CPB-DEL group.

CONCLUSION

Tau and NfL might be of benefit to identify patients in cardiac surgery at risk for delirium and to detect patients with the postoperative emergence of delirium.

MIECT: How did it start?

Transiently assuming the functions of both heart and lungs as surgeons repair critical valves and vessel lesions can be achieved by mechanical circulatory support has its origins in cardiopulmonary bypass (CPB). However, CPB technologies induce also some unintended adverse effects. During the 90s, a mayor trend pushed many physicians to reconsider the place of coronary artery bypass grafting (CABG) and challenged the surgical reference treatment by less invasive catheter-based angioplasties. Nevertheless, best long-term patient outcomes were related to surgery. Therefore, a small number of multidisciplinary teams in Regensburg and Paris started to develop a minimally invasive CPB system. The basic concept relied on a closed-loop perfusion circuit with a non-occlusive pump. Moreover, the team in Paris pushed the concept further and developed a complete fully integrated CPB system allowed first closed-heart and later open-heart surgery with aortic cross-clamping and efficient cardioprotection. Those were the initial steps towards the future developments of minimally invasive extracorporeal circulation technologies. Initial clinical results were clearly positive in terms of overall morbimortality. Moreover, several preliminary results pointed out the biological benefits that decreased hemodilution, improved preservation of the immune reactions and more stable anticoagulation could bring to the field of ECT.

Genome-wide association study of myocardial infarction, atrial fibrillation, acute stroke, acute kidney injury and delirium after cardiac surgery - a sub-analysis of the RIPHeart-Study

Background

The aim of our study was the identification of genetic variants associated with postoperative complications after cardiac surgery.

Methods

We conducted a prospective, double-blind, multicenter, randomized trial (RIPHeart). We performed a genome-wide association study (GWAS) in 1170 patients of both genders (871 males, 299 females) from the RIPHeart-Study cohort. Patients undergoing non-emergent cardiac surgery were included. Primary endpoint comprises a binary composite complication rate covering atrial fibrillation, delirium, non-fatal myocardial infarction, acute renal failure and/or any new stroke until hospital discharge with a maximum of fourteen days after surgery.

Results

A total of 547,644 genotyped markers were available for analysis. Following quality control and adjustment for clinical covariate, one SNP reached genome-wide significance (PHLPP2, rs78064607, p = 3.77 × 10^− 8) and 139 (adjusted for all other outcomes) SNPs showed promising association with p < 1 × 10^− 5 from the GWAS.

Conclusions

We identified several potential loci, in particular PHLPP2, BBS9, RyR2, DUSP4 and HSPA8, associated with new-onset of atrial fibrillation, delirium, myocardial infarction, acute kidney injury and stroke after cardiac surgery.

Trial registration

The study was registered with ClinicalTrials.gov NCT01067703, prospectively registered on 11 Feb 2010.

Electronic supplementary material

The online version of this article (10.1186/s12872-019-1002-x) contains supplementary material, which is available to authorized users.

Extracellular vesicles: biomarkers and regulators of vascular function during extracorporeal circulation

Extracellular vesicles (EVs) are generated at increased rates from parenchymal and circulating blood cells during exposure of the circulation to abnormal flow conditions and foreign materials associated with extracorporeal circuits (ExCors). This review describes types of EVs produced in different ExCors and extracorporeal life support (ECLS) systems including cardiopulmonary bypass circuits, extracorporeal membrane oxygenation (ECMO), extracorporeal carbon dioxide removal (ECCO₂R), apheresis, dialysis and ventricular assist devices. Roles of EVs not only as biomarkers of adverse events during ExCor/ECLS use, but also as mediators of vascular dysfunction are explored. Manipulation of the number or subtypes of circulating EVs may prove a means of improving vascular function for individuals requiring ExCor/ECLS support. Strategies for therapeutic manipulation of EVs during ExCor/ECLS use are discussed such as accelerating their clearance, preventing their genesis or pharmacologic options to reduce or select which and how many EVs circulate. Strategies to reduce or select for specific types of EVs may prove beneficial in preventing or treating other EV-related diseases such as cancer.

Oxidative Stress and Neonatal Respiratory Extracorporeal Membrane Oxygenation

Oxidative stress is a frequent condition in critically ill patients, especially if exposed to extracorporeal circulation, and it is associated with worse outcomes and increased mortality. The inflammation triggered by the contact of blood with a non-endogenous surface, the use of high volumes of packed red blood cells and platelets transfusion, the risk of hyperoxia and the impairment of antioxidation systems contribute to the increase of reactive oxygen species and the imbalance of the redox system. This is responsible for the increased production of superoxide anion, hydrogen peroxide, hydroxyl radicals, and peroxynitrite resulting in increased lipid peroxidation, protein oxidation, and DNA damage. The understanding of the pathophysiologic mechanisms leading to redox imbalance would pave the way for the future development of preventive approaches. This review provides an overview of the clinical impact of the oxidative stress during neonatal extracorporeal support and concludes with a brief perspective on the current antioxidant strategies, with the aim to focus on the potential oxidative stress-mediated cell damage that has been implicated in both short and long-term outcomes.

Peroxidase-Mimicking Nanoassembly Mitigates Lipopolysaccharide-Induced Endotoxemia and Cognitive Damage in the Brain by Impeding Inflammatory Signaling in Macrophages

Oxidative stress during sepsis pathogenesis remains the most-important factor creating imbalance and dysregulation in immune-cell function, usually observed following initial infection. Hydrogen peroxide (H₂O₂), a potentially toxic reactive oxygen species (ROS), is excessively produced by pro-inflammatory immune cells during the initial phases of sepsis and plays a dominant role in regulating the pathways associated with systemic inflammatory immune activation. In the present study, we constructed a peroxide scavenger mannosylated polymeric albumin manganese dioxide (mSPAM) nanoassembly to catalyze the decomposition of H₂O₂ responsible for the hyper-activation of pro-inflammatory immune cells. In a detailed manner, we investigated the role of mSPAM nanoassembly in modulating the expression and secretion of pro-inflammatory markers elevated in bacterial lipopolysaccharide (LPS)-mediated endotoxemia during sepsis. Through a facile one-step solution-phase approach, hydrophilic bovine serum albumin reduced manganese dioxide (BM) nanoparticles were synthesized and subsequently self-assembled with cationic mannosylated disulfide cross-linked polyethylenimine (mSP) to formulate mSPAM nanoassembly. In particular, we observed that the highly stable mSPAM nanoassembly suppressed HIF1α expression by scavenging H₂O₂ in LPS-induced macrophage cells. Initial investigation revealed that a significant reduction of free radicals by the treatment of mSPAM nanoassembly has reduced the infiltration of neutrophils and other leukocytes in a local endotoxemia animal model. Furthermore, therapeutic studies in a systemic endotoxemia model demonstrated that mSPAM treatment reduced TNF-α and IL-6 inflammatory cytokines in serum, in turn circumventing organ damage done by the inflammatory macrophages. Interestingly, we also observed that the reduction of these inflammatory cytokines by mSPAM nanoassembly further prevented IBA-1 immuno-positive microglial cell activation in the brain and consequently improved the cognitive function of the animals. Altogether, the administration of mSPAM nanoassembly scavenged H₂O₂ and suppressed HIF1α expression in LPS-stimulated macrophages and thereby inhibited the progression of local and systemic inflammation as well as neuroinflammation in an LPS-induced endotoxemia model. This mSPAM nanoassembly system could serve as a potent anti-inflammatory agent, and we further anticipate its successful application in treating various inflammation-related diseases.

Deposition of mannose-binding lectin and ficolins and activation of the lectin pathway of complement on the surface of polyurethane tubing used for cardiopulmonary bypass

The artificial surface used for cardiopulmonary bypass (CPB) is a crucial factor activating the complement system and thus contributing to the generation of a systemic inflammatory response. The activation of classical and alternative pathways on this artificial surface is well known. In contrast, lectin pathway (LP) activation has not been fully investigated, although noted during CPB in several studies. Moreover, we have recently proved the contribution of the LP to the generation of the systemic inflammatory response syndrome after pediatric cardiac surgery. The aim of this study was to assess LP-mediated complement activation on the surface of polyurethane CPB circuit tubing (noncoated Chalice ® ), used for CPB procedures in children with congenital heart disease. We found deposition of mannose-binding lectin, ficolin-1, -2, and -3 on the surface of unused tubing and on tubing used for CPB from a small minority of patients. Furthermore, we observed deposition of complement C4 activation products on tubing used for CPB and previously unused tubing after incubation with normal serum. The latter finding indicates LP activation in vitro on the polyurethane surface. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1202-1208, 2018.

Inflammation and Its Consequences After Surgical Versus Transcatheter Aortic Valve Replacement

Symptomatic aortic stenosis can be treated by surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR), the latter of which is regarded as a minimally invasive procedure. Differences between these procedures regarding immune responses or changes in coagulation and neurocognitive function have thus far been evaluated only sparsely. We carried out a prospective, single-center, nonrandomized explorative study with 38 patients. Thirteen patients were subjected to either SAVR or transfemoral (TF-) TAVR, and 12 patients underwent transapical (TA-) TAVR. Plasma cytokines (IL-6, -8, -18, presepsin) and acute-phase proteins (C-reactive protein, procalcitonin), markers of coagulation and platelet function, and neurocognitive function (via various standard tests) were assessed before and at five-time points during a 72-h follow-up after surgery. SAVR and TA-TAVR patients responded similarly to the procedure in terms of C-reactive protein, leukocyte numbers, and IL-6, whereas these responses were substantially lower in TF-TAVR patients. Only SAVR patients showed measurable IL-10 levels. SAVR patients without prior anticoagulation experienced a robust and transient restoration of platelet function after surgery, with no hypercoagulation observable in functional coagulation assays. None of the procedures led to an immediate improvement of hand and leg coordination, but patients after TA-TAVR had decreased neurocognitive function. Patients after SAVR or TA-TAVR exhibit a robust pro-inflammatory response, which is-on the cytokine level-counterbalanced only in SAVR patients. Our results point toward a greater impact of TA-TAVR on neurocognitive function and indicate a potentially detrimental activation of platelets in some patients after SAVR.

Shed-blood-separation and cell-saver: an integral Part of MiECC? Shed-blood-separation and its influence on the perioperative inflammatory response during coronary revascularization with minimal invasive extracorporeal circulation systems – a randomized controlled trial

Objective:

The postoperative systemic inflammatory response after cardiopulmonary bypass (CPB) is still an undesirable side-effect after cardiac surgery. It is most likely caused by blood contact with foreign surfaces and by the surgical trauma itself. However, the recirculation of activated shed mediastinal blood is another main cause of blood cell activation and cytokine release. Minimal invasive extracorporeal circulation (MiECC) comprises a completely closed circuit, coated surfaces and the separation of suction blood. We hypothesized that MiECC, with separated cell saved blood, would induce less of a systemic inflammatory response than MiECC with no cell-saver. The aim of this study was, therefore, to investigate the impact of cell washing shed blood from the operating field versus direct return to the ECC on the biomarkers for systemic inflammation.

Material and methods:

In the study, patients with MiECC and cell-saver were compared with the control group, patients with MiECC and direct re-transfusion of the drawn blood shed from the surgical field.

Results:

High amounts of TNF-α (+ 120% compared to serum blood) were found in the shed blood itself, but a significant reduction was demonstrated with the use of a cell-saver (TNF-α ng/l post-ECC 10 min: 9.5±3.5 vs. 19.7±14.5, p<0.0001). The values for procalcitonin were not significantly increased in the control group (6h: 1.07±3.4 vs. 2.15±9.55, p=0.19) and lower for C-reactive protein (CRP) (24h: 147.1±64.0 vs.134.4±52.4 p=0.28).

Conclusion:

The use of a cell-saver and the processing of shed blood as an integral part of MiECC significantly reduces the systemic cytokine load. We, therefore, recommend the integration of cell-saving devices in MiECC to reduce the perioperative inflammatory response.

Analysis of the influence of respiratory disorders observed in preoperative spirometry on the dynamics of early inflammatory response in patients undergoing isolated coronary artery bypass grafting

Background

Preoperative spirometry provides measurable information about the occurrence of respiratory disorders. The aim of this study was to assess the association between preoperative spirometry abnormalities and the intensification of early inflammatory responses in patients following coronary artery bypass graft in extracorporeal circulation.

Material and methods

The study involved 810 patients (625 men and 185 women) aged 65.4±7.9 years who were awaiting isolated coronary artery bypass surgery. On the basis of spirometry performed on the day of admittance to the hospital, the patients were divided into three groups. Patients without respiratory problems constituted 78.8% of the entire group. Restricted breathing was revealed by spirometry in 14.9% and obstructive breathing in 6.3% of patients.

Results

Inter-group analysis showed statistically significant differences in C-reactive protein (CRP) between patients with restrictive spirometry abnormalities and patients without any pulmonary dysfunction. CRP concentrations differed before surgery (P=0.006) and on the second (P<0.001), fourth (P=0.005) and sixth days after surgery (P=0.029). There was a negative correlation between CRP levels and FEV₁.

Conclusion

In our study, the most common pulmonary disorders in the coronary artery bypass graft patients were restrictive. Patients with abnormal spirometry results from restrictive respiratory disorders have an elevated level of generalized inflammatory response both before and after the isolated coronary artery bypass surgery. Therefore, this group of patients should be given special postoperative monitoring and, in particular, intensive respiratory rehabilitation immediately after reconstitution.

Metabolomic profiling in patients undergoing Off-Pump or On-Pump coronary artery bypass surgery

Background

Coronary artery bypass surgery can be performed without (Off-Pump) or with cardiopulmonary bypass (On-Pump). Extracorporeal circulation and cardioplegic arrest may cause alterations in the plasma metabolome. We assessed metabolomic changes in patients undergoing On-Pump or Off-Pump coronary artery bypass surgery.

Methods

We assessed five analyte classes (41 acylcarnitines, 14 amino acids, 92 glycerophospholipids, 15 sphingolipids, sugars, lactate) using a mass-spectrometry-based kit (Biocrates AbsoluteIDQ® p150) in paired arterial and coronary sinus blood obtained from 10 consecutive On-Pump and 10 Off-Pump patients. Cardioplegia for On-Pump was warm blood Calafiore. On-Pump outcomes were corrected for hemodilution through crystalloid priming.

Results

Demographic data were equal in both groups with normal ejection fraction, renal and liver function. Patients received 2.25 ± 0.64 bypass grafts. All postoperative courses were uneventful. Of 164 measured metabolites, only 13 (7.9%) were altered by cardiopulmonary bypass. We found more long-chain acylcarnitines Off-Pump and more short-chain acylcarnitines On-Pump. Glycerophospholipids showed lower concentrations On-Pump and arginine (as the only different amino acid) Off-Pump. Interestingly, plasma arginine (nitric oxide precursor) concentration at the end of surgery correlated inversely with postoperative vasopressor need (r = −0.7; p < 0.001). Assessing arterial/venous differences revealed phosphatidylcholine-production and acylcarnitine-consumption. These findings were unaffected by cardiopulmonary bypass, cardioplegia or temporary vessel occlusion during Off-Pump surgery.

Conclusions

Cardiopulmonary bypass and warm blood cardioplegia cause only minor changes to the metabolomic profile of patients undergoing coronary artery bypass surgery. The observed changes affected mainly acylcarnitines. In addition, there appears to be a relationship between arginine and vasopressor need after bypass surgery.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-017-0518-1) contains supplementary material, which is available to authorized users.

The inflammatory response to extracorporeal membrane oxygenation (ECMO): a review of the pathophysiology

Extracorporeal membrane oxygenation (ECMO) is a technology capable of providing short-term mechanical support to the heart, lungs or both. Over the last decade, the number of centres offering ECMO has grown rapidly. At the same time, the indications for its use have also been broadened. In part, this trend has been supported by advances in circuit design and in cannulation techniques. Despite the widespread adoption of extracorporeal life support techniques, the use of ECMO remains associated with significant morbidity and mortality. A complication witnessed during ECMO is the inflammatory response to extracorporeal circulation. This reaction shares similarities with the systemic inflammatory response syndrome (SIRS) and has been well-documented in relation to cardiopulmonary bypass. The exposure of a patient’s blood to the non-endothelialised surface of the ECMO circuit results in the widespread activation of the innate immune system; if unchecked this may result in inflammation and organ injury. Here, we review the pathophysiology of the inflammatory response to ECMO, highlighting the complex interactions between arms of the innate immune response, the endothelium and coagulation. An understanding of the processes involved may guide the design of therapies and strategies aimed at ameliorating inflammation during ECMO. Likewise, an appreciation of the potentially deleterious inflammatory effects of ECMO may assist those weighing the risks and benefits of therapy.

Regular plateletpheresis increased basal concentrations of soluble P-selectin in healthy donors: Possible involvement of endothelial cell activation?

BACKGROUND

We explored the effects of repeated plateletpheresis on the platelet P-selectin expression and soluble P-selectin (sP-selectin) concentrations in platelet donors.

METHODS

Totally 289 platelet donors and 97 first-time whole blood (WB) donors were enrolled from the blood donor registry at the Fujian provincial blood center, China. The accumulative numbers of plateletpheresis in the last 2 y for participants were recorded, and the basal concentrations of platelet count, sP-selectin and total platelet P-selectin (pP-selectin) were determined.

RESULTS

Platelet donors had significantly higher basal concentrations of sP-selectin compared to WB donors (24.12±7.33ng/mL vs. 20.74±5.44ng/mL, P<0.0001), with no difference in platelet count and pP-selectin concentrations. Increased numbers of platelet donation were correlated with a steady increase of sP-selectin (r=0.18, P=0.002). Multivariate regression analysis identified that the frequency of plateletpheresis is an independent factor for the rise of the sP-selectin concentration (t=2.64, P=0.009) while no association was found for pP-selectin and platelet count.

CONCLUSIONS

Repeated plateletpheresis could result in an increased basal concentration of sP-selectin in blood donors whereas not an alteration in the concentrations of total platelet P-selectin. It remains to be determined whether this might be a consequence of endothelial activation or platelet activation or some other phenomenon.

Ulinastatin administration is associated with a lower incidence of acute kidney injury after cardiac surgery: a propensity score matched study

BACKGROUND

Systemic inflammation is involved in the development of acute kidney injury (AKI) after cardiac surgery with cardiopulmonary bypass (CPB). Ulinastatin, a urinary trypsin inhibitor (UTI), possesses a variety of anti-inflammatory effects. Therefore, we hypothesized that the administration of ulinastatin would reduce the occurrence of AKI in patients undergoing cardiac surgery with CPB.

METHODS

A retrospective propensity score matched analysis was used to evaluate the effect of ulinastatin on the development of AKI in patients undergoing first documented cardiac surgery with CPB between January 2008 and December 2012 in our hospital. Multiple logistic regression models were also employed to identify the association between UTI administration and development of AKI.

RESULTS

A total of 2072 patients who underwent cardiac surgery with CPB met the inclusion criteria. Before propensity score matching, variables such as age, baseline creatinine, CPB duration, red blood cells transfused, and hematocrit were statistically different between the ulinastatin (UTI) group and the control group. On the basis of propensity scores, 409 UTI patients were successfully matched to the 409 patients from among those 1663 patients without UTI administration. After propensity score matching, no statistically significant differences in the baseline characteristics were found between the UTI group and the control group. The propensity score matched cohort analysis revealed that AKI and the need for renal replacement therapy occurred more frequently in the control group than in the UTI group (40.83% vs. 30.32%, P = 0.002; 2.44% vs. 0.49%, P = 0.02, respectively). However, there were no significant differences in mortality, length of intensive care unit stay, and length of hospital stay between the UTI group and the control group. Using multivariate logistic regression analysis, we found ulinastatin played a protective role in the development of AKI after cardiac surgery (odds ratio 0.71, 95% confidence interval 0.56-0.90, P = 0.005).

CONCLUSIONS

This study shows that ulinastatin was associated with a lower incidence of AKI after cardiac surgery, suggesting that the administration of ulinastatin may be favorable for those patients undergoing cardiac surgery with CPB.

Noteworthy Literature in 2015

This article is a review of the literature published during the 12 months of 2015, which is of interest to the congenital cardiac anesthesiologist. While the review is not exhaustive, it identifies 7 themes in the literature for 2015 and cites 78 peer-reviewed publications.

Endogenous Ouabain: An Old Cardiotonic Steroid as a New Biomarker of Heart Failure and a Predictor of Mortality after Cardiac Surgery

Cardiovascular diseases remain the main cause of mortality and morbidity worldwide; primary prevention is a priority for physicians. Biomarkers are useful tools able to identify high-risk individuals, guide treatments, and determine prognosis. Our aim is to investigate Endogenous Ouabain (EO), an adrenal stress hormone with hemodynamic effects, as a valuable biomarker of heart failure. In a population of 845 patients undergoing elective cardiac surgery, we have investigated the relationships between EO and echocardiography parameters/plasmatic biomarker of cardiac function. EO was found to be correlated negatively with left ventricular EF (p = 0.001), positively with Cardiac End-Diastolic Diameter (p = 0.047), and positively with plasmatic NT-proBNP level (p = 0.02). Moreover, a different plasmatic EO level (both preoperative and postoperative) was found according to NYHA class (p = 0.013). All these results have been replicated on an independent cohort of patients (147 subjects from US). Finally, a higher EO level in the immediate postoperative time was indicative of a more severe cardiological condition and it was associated with increased perioperative mortality risk (p = 0.023 for 30-day morality). Our data suggest that preoperative and postoperative plasmatic EO level identifies patients with a more severe cardiovascular presentation at baseline. These patients have a higher risk of morbidity and mortality after cardiac surgery.