Modulation of systemic inflammatory response after cardiac surgery

Strategies to attenuate maladaptive inflammatory response associated with cardiopulmonary bypass

Cardiopulmonary bypass (CPB) initiates an intense inflammatory response due to various factors: conversion from pulsatile to laminar flow, cold cardioplegia, surgical trauma, endotoxemia, ischemia-reperfusion injury, oxidative stress, hypothermia, and contact activation of cells by the extracorporeal circuit. Redundant and overlapping inflammatory cascades amplify the initial response to produce a systemic inflammatory response, heightened by coincident activation of coagulation and fibrinolytic pathways. When unchecked, this inflammatory response can become maladaptive and lead to serious postoperative complications. Concerted research efforts have been made to identify technical refinements and pharmacologic interventions that appropriately attenuate the inflammatory response and ultimately translate to improved clinical outcomes. Surface modification of the extracorporeal circuit to increase biocompatibility, miniaturized circuits with sheer resistance, filtration techniques, and minimally invasive approaches have improved clinical outcomes in specific populations. Pharmacologic adjuncts, including aprotinin, steroids, monoclonal antibodies, and free radical scavengers, show real promise. A multimodal approach incorporating technical, circuit-specific, and pharmacologic strategies will likely yield maximal clinical benefit.

Reverse Septal Movement: A Step Forward in the Comprehension of the Underlying Causes

(1) Background: Reverse septal movement (RSM) often occurs after cardiac surgery, consisting of a paradoxical systolic movement of the interventricular septum. In this retrospective study, we aimed to investigate possible determinants of RSM after coronary artery bypass surgery (CABG). (2) Methods: Patients who underwent CABG with on- or off-pump techniques at our center from March 2019 to October 2021 were retrospectively included. Exclusion criteria were: exposure to combined procedures (e.g., valve implantation), prior cardiac surgery, intraventricular conduction delays, and previous pacemaker implantation. Laboratory tests and echocardiographic and cardiopulmonary bypass (CPB) duration data were collected. (3) Results: We enrolled 138 patients, of whom 32 (23.2%) underwent off-pump CABG. Approximately 89.1% of the population was male; the mean age was 70 ± 11 years. There was no difference in RSM incidence in patients undergoing the off-pump and on-pump techniques (71.9% vs. 62.3%; p = 0.319). In patients undergoing on-pump surgery, the incidence of RSM was slightly higher in longer CPB procedures (OR 1.02 (1.00-1.03) p = 0.012), and clamping aortic time was also greater (OR 1.02 (1.00-1.03) p = 0.042). (4) Conclusions: CPB length seems to be correlated with a higher RSM appearance. This better knowledge of RSM reinforces the safety of CABG and its neutral effect on global biventricular function.

Lung injury following cardiopulmonary bypass: a clinical update

INTRODUCTION

Cardiopulmonary bypass (CPB) is an integral component of cardiac surgery; however, one of its most critical complications is acute lung injury induced by multiple factors including systemic inflammatory response.

AREAS COVERED

The objective of this review is to investigate the multiple factors that can lead to CPB-induced lung injury. These include contact of blood components with the artificial surface of the CPB circuit, local and systemic inflammatory response syndrome (SIRS), lung ischemia/re-perfusion injury, arrest of ventilation, and circulating endotoxins. We also focus on possible interventions to curtail the negative impact of CPB, such as off-pump surgery, impregnation of the circuit with less biologically active substances, leukocyte depletion filters and ultrafiltration, and pharmacological agents such as steroids and aprotinin.

EXPERT OPINION

Although many aspects of CPB are proposed to contribute to lung injury, its overall role is still not clear. Multiple interventions have been introduced to reduce the risk of pulmonary dysfunction, with many of these interventions having shown promising results, significantly attenuating inflammatory mediators and improving post-operative outcome. However, since lung injury is multifactorial and affected by inextricably linked components, multiple interventions tackling each of them is required.

Nomogram and risk calculator for severe hypoxemia after heart valve surgery

Background

Hypoxemia is a very common issue in patients undergoing heart valve surgery (HVS), related to poor clinical outcomes. However, studies on severe hypoxemia (SH) after HVS have not been reported. The aims of this study were to identify predictors for SH in patients undergoing HVS and to develop and validate a risk prediction model.

Methods

Patients undergoing HVS between 2016 and 2019 in a cardiovascular center were enrolled and were assigned to training and validation sets by a 7:3 ratio. Based on whether patients developed SH, they were divided into two groups. By univariate and multivariate analysis, predictors for SH were identified. Based on the predictors and logistic rule, a nomogram and a risk calculator were generated. The model was evaluated using calibration, discrimination and clinical utility.

Results

The incidence rates of SH, moderate hypoxemia and mild hypoxemia were respectively 2.4, 23.9, and 58.2%. By multivariate analysis, seven independent risk factors for SH after HVS were identified, including body mass index, chronic obstructive pulmonary disease, renal insufficiency, white blood cell count, serum globulin, cardiopulmonary bypass time, and surgical types. The logistic model demonstrated satisfactory discrimination, calibration and clinical utility in both the training and validation sets. A nomogram and a risk calculator based on the logistic model were generated for easy application. Risk stratification was performed and three risk intervals were defined according to the nomogram and clinical practice. In addition, compared to patients without SH, patients with SH had significantly poorer clinical outcomes.

Conclusions

Postoperative hypoxemia was prevalent after HVS, related to poor clinical outcomes. A logistic model including seven independent predictors for SH after HVS were established and validated, which demonstrated satisfactory discrimination, calibration and clinical utility. The results of this study may provide help to individualized risk assessment, early prevention and perioperative management.

Incidence, Risk Factors, and Outcomes of Severe Hypoxemia After Cardiac Surgery

Background

Hypoxemia is common in patients undergoing cardiac surgery, however, few studies about severe hypoxemia (SH) after cardiac surgery exist. The objectives of this study were to clarify the incidence, risk factors, and outcomes of SH after cardiac surgery.

Methods

Patients undergoing cardiac surgery from 2016 to 2019 in a single center were enrolled and were divided into two groups based on whether postoperative SH developed. Independent risk factors for SH were identified by univariate and multivariate analysis. Model selection statistics were applied to help determine the most parsimonious final model.

Results

Severe hypoxemia developed in 222 of the 5,323 included patients (4.2%), was associated with poorer clinical outcomes. Six independent risk factors for SH after cardiac surgery were identified by multivariate analysis, such as surgical types, white blood cell (WBC) count, body mass index (BMI), serum albumin, cardiopulmonary bypass (CPB) time, and intraoperative transfusion of red blood cells (RBCs). After comprehensively considering the discrimination, calibration, and simplicity, the most appropriate and parsimonious model was finally established using four predictors, such as WBC count, BMI, CPB time, and intraoperative transfusion of RBCs. A nomogram and a web-based risk calculator based on the final model were constructed to facilitate clinical practice. Patients were stratified into three risk groups based on the nomogram and clinical practice.

Conclusion

Severe hypoxemia was common after cardiac surgery and was associated with poorer clinical outcomes. A parsimonious final model with good discrimination, calibration, and clinical utility was constructed, which may be helpful for personalized risk assessment and targeted intervention.

Evaluation of low-dose colchicine in patients with cardiopulmonary bypass: study protocol for a randomised controlled trial

INTRODUCTION

Inflammation and myocardial damage caused by cardiovascular surgery with cardiopulmonary bypass (CPB) have been shown to be the major contributors to postoperative morbidity and mortality. Colchicine can reduce myocardial ischaemia-reperfusion injury in patients with chronic coronary artery disease. However, there is a lack of evidence whether colchicine could reduce myocardial injury after cardiovascular surgery. In this study, we aim to evaluate the effect of low-dose colchicine on myocardial protection during perioperative period in patients who undergo cardiovascular surgery with CPB.

METHODS AND ANALYSIS

In this randomised controlled trial, a total of 132 patients will be recruited from the Department of Cardio-Thoracic Surgery, Nanjing Drum Tower Hospital. Patients will be randomised into the colchicine treatment group and control group with a ratio of 1:1. Patients in the colchicine treatment group will receive 0.5 mg of colchicine daily for 3 days before surgery and 0.5 mg of colchicine daily for 5 days after surgery. Patients in the control group will receive placebo instead of colchicine for the same schedule. Level of postoperative myocardial injury will be assessed as the primary outcome. The secondary outcomes are biomarker levels for myocardial injury (such as creatine kinase-MB, cardiac troponin I, myohaemoglobin, type B natriuretic peptide, D-dimer) and inflammatory response markers (white blood cell, procalcitonin, interleukin-6, C reactive protein) for 5 consecutive days after surgery and poor postoperative outcomes.

ETHICS AND DISSEMINATION

This study has been approved by Medical Ethics Committee of Affiliated Nanjing Drum Tower Hospital, Nanjing University Medical College (approval number: 2020-293-01). Study results will be disseminated through publication in an open access journal.

TRIAL REGISTRATION NUMBER

ChiCTR2000040129.

Validation of Point-of-Care Ultrasound to Measure Perioperative Edema in Infants With Congenital Heart Disease

Purpose: Fluid overload is a common post-operative issue in children following cardiac surgery and is associated with increased morbidity and mortality. There is currently no gold standard for evaluating fluid status. We sought to validate the use of point-of-care ultrasound to measure skin edema in infants and assess the intra- and inter-user variability. Methods: Prospective cohort study of neonates (≤30 d/o) and infants (31 d/o to 12 m/o) undergoing cardiac surgery and neonatal controls. Skin ultrasound was performed on four body sites at baseline and daily post-operatively through post-operative day (POD) 3. Subcutaneous tissue depth was manually measured. Intra- and inter-user variability was assessed using intraclass correlation coefficient (ICC). Results: Fifty control and 22 surgical subjects underwent skin ultrasound. There was no difference between baseline surgical and control neonates. Subcutaneous tissue increased in neonates starting POD 1 with minimal improvement by POD 3. In infants, this pattern was less pronounced with near resolution by POD 3. Intra-user variability was excellent (ICC 0.95). Inter-user variability was very good (ICC 0.82). Conclusion: Point-of-care skin ultrasound is a reproducible and reliable method to measure subcutaneous tissue in infants with and without congenital heart disease. Acute increases in subcutaneous tissue suggests development of skin edema, consistent with extravascular fluid overload. There is evidence of skin edema starting POD 1 in all subjects with no substantial improvement by POD 3 in neonates. Point-of-care ultrasound could be an objective way to measure extravascular fluid overload in infants. Further research is needed to determine how extravascular fluid overload correlates to clinical outcomes.

Tissue alkaline phosphatase activity and expression in an experimental infant swine model of cardiopulmonary bypass with deep hypothermic circulatory arrest

Background

Infant cardiac surgery with cardiopulmonary bypass results in decreased circulating alkaline phosphatase that is associated with poor postoperative outcomes. Bovine intestinal alkaline phosphatase infusion represents a novel therapy for post-cardiac surgery organ injury. However, the effects of cardiopulmonary bypass and bovine-intestinal alkaline phosphatase infusion on tissue-level alkaline phosphatase activity/expression are unknown.

Methods

Infant pigs (n = 20) underwent cardiopulmonary bypass with deep hypothermic circulatory arrest followed by four hours of intensive care. Seven control animals underwent mechanical ventilation only. Cardiopulmonary bypass/deep hypothermic circulatory arrest animals were given escalating doses of bovine intestinal alkaline phosphatase infusion (0-25 U/kg/hr.; n = 5/dose). Kidney, liver, ileum, jejunum, colon, heart and lung were collected for measurement of tissue alkaline phosphatase activity and mRNA.

Results

Tissue alkaline phosphatase activity varied significantly across organs with the highest levels found in the kidney and small intestine. Cardiopulmonary bypass with deep hypothermic circulatory arrest resulted in decreased kidney alkaline phosphatase activity and increased lung alkaline phosphatase activity, with no significant changes in the other organs. Alkaline phosphatase mRNA expression was increased in both the lung and the ileum. The highest dose of bovine intestinal alkaline phosphatase resulted in increased kidney and liver tissue alkaline phosphatase activity.

Conclusions

Changes in alkaline phosphatase activity after cardiopulmonary bypass with deep hypothermic circulatory arrest and bovine intestinal alkaline phosphatase delivery are tissue specific. Kidneys, lung, and ileal alkaline phosphatase appear most affected by cardiopulmonary bypass with deep hypothermic circulatory arrest and further research is warranted to determine the mechanism and biologic importance of these changes.

Ten-year improved survival in patients with multi-vessel coronary disease and poor left ventricular function following surgery: A retrospective cohort study

OBJECTIVE

Patients with multi-vessel coronary artery disease and poor left ventricular (LV) function (ejection fraction [EF] < 30%) requiring revascularization are considered 'high-risk'. Limited long-term survival data exists comparing percutaneous coronary intervention (PCI) with second-generation drug-eluting stents (DES) versus surgery for this cohort of patients.

METHODS

We retrospectively reviewed our data for 321 patients with EF < 30% who underwent multi-vessel revascularization from January 2005 to December 2015 using Cox regression analyses and inverse probability treatment weighted (IPTW) methods. We stratified patients that underwent surgical revascularization into on-pump coronary artery bypass grafting (CABG) and off-pump CABG and analyzed all-cause mortality at 10 years compared to PCI.

RESULTS

214 patients underwent CABG (n [on-pump CABG] = 94; n [off-pump CABG] = 120) and 107 patients had PCI with second generation DES. PCI with DES had higher 10-year mortality compared with on-pump CABG (Hazard ratio [HR] = 1.86, 95% confidence interval [CI] = 1.46-2.42; p < 0.001) and off-pump CABG (HR = 2.32, 95% CI = 1.75-3.15; p < 0.001). This was confirmed in IPTW analyses. When adjusting for both measured and unmeasured factors using instrumental variable analyses, PCI with DES had higher 10-year mortality compared with on-pump CABG (Δ = 13.5, 95% CI = 3.2-24.5; p = 0.012) and off-pump CABG (Δ = 16.1, 95% CI = 5.9-25.8; p < 0.001).

CONCLUSION

Surgical revascularization, preferably off-pump CABG, results in better long-term survival compared with PCI using second generation DES for patients with multi-vessel coronary artery disease and poor left ventricular function. Randomized controlled trials in this patient group should be undertaken.

Infant cardiopulmonary bypass: CD73 kinetics, association with clinical outcomes, and influence on serum adenosine production capacity

BackgroundExtracellular adenine nucleotides contribute to ischemia-reperfusion injury following infant cardiopulmonary bypass (CPB), whereas conversion to adenosine may be protective. Alkaline phosphatase (AP), a key enzyme responsible for this conversion, decreases after infant CPB. Indirect evidence suggests that soluble CD73 may simultaneously increase and partially offset this loss of AP. We sought to measure CD73 levels in infants undergoing CPB and determine its association with adenosine production capacity and postoperative support requirements.MethodsA prospective cohort study of infants ≤120 days of age undergoing CPB. CD73 was measured before CPB and during rewarming. Multivariable modeling evaluated the contributions of CD73/AP to adenosine production capacity and postoperative support requirements.ResultsSerum samples from 85 subjects were analyzed. The median CD73 concentration increased following CPB (95.2 vs. 179.8 ng/ml; P<0.0001). Rewarming CD73 was independently inversely associated with vasoactive inotropic support (P<0.005) and length of intensive care unit stay (P<0.005). Combined AP activity and CD73 concentration predicted adenosine production capacity (P<0.0001).ConclusionsSerum CD73 increases following infant CPB. Low rewarming CD73 is independently associated with increased postoperative support requirements. CD73 and AP together predict serum adenosine production capacity and may represent potential therapeutic targets to clear extracellular adenine nucleotides and improve outcomes following infant CPB.

Risk factors for hypoxemia following surgical repair of acute type A aortic dissection

Objectives

To identify the risk factors for hypoxaemia following surgical repair of acute type A aortic dissection.

Methods

This was a retrospective study of patients treated between October 2013 and December 2014 at the Department of Cardiovascular Surgery, Anzhen Hospital, China. Univariable and multivariable analyses were performed on the clinical data of 160 patients with acute type A dissection and who underwent ascending aortic and arch replacement under deep hypothermic circulatory arrest.

Results

Hypoxaemia occurred in 30% (48/160) of patients (age: 49 ± 7.9 years; 40 males, 83.3%). The duration of ventilation and the lengths of intensive care unit and hospital stays were significantly longer in patients with hypoxemia (77.9 ± 56.0 vs 16.5 ± 11.5 h, P < 0.0001; 6.0 ± 2.3 vs 2.0 ± 1.2 days, P = 0.001; 18.1 ± 6.3 vs 13.5 ± 4.7 days, P = 0.0012; respectively). The difference in operative mortality was not statistically significant between the hypoxaemia and non-hypoxaemia groups (6.25% vs 3.57%, P = 0.351). The independent risk factors of postoperative hypoxaemia were time from symptom onset to surgery ≤72 h [odds ratio, 3.63; 95% confidence interval, 1.31-10.02; P = 0.013], preoperative PaO2/FiO2 ≤300 (odds ratio, 15.30; 95% CI, 5.52-42.43; P < 0.001), preoperative white blood cell count >15 000/μl (odds ratio, 9.79; 95% CI, 2.47-38.87; P = 0.001); and deep hypothermic circulatory arrest time >25 min (odds ratio, 3.26; 95% CI, 1.18-8.99; P = 0.023).

Conclusions

Time from symptom onset to surgery ≤72 h, preoperative PaO2/FiO2 ≤300, white blood cell count >15 000/μl and deep hypothermic circulatory arrest time >25 min were found to be independently associated with hypoxaemia after surgery for acute type A aortic dissection.

Modulation of Immunologic Response by Preventive Everolimus Application in a Rat CPB Model

Everolimus (EVL) is widely used in solid organ transplantation. It is known to have antiproliferative and immunosuppressive abilities via inhibition of the mTOR pathway. Preventive EVL administration may lower inflammation induced by cardiopulmonary bypass (CPB) and reduce systemic inflammatory response syndrome (SIRS). After oral loading with EVL 2.5 mg/kg/day (n = 11) or placebo (n = 11) for seven consecutive days, male Wistar rats (400-500 g) were connected to a miniaturised heart-lung-machine performing a deep hypothermic circulatory arrest protocol. White blood cells (WBC) were significantly reduced in EVL-pretreated animals before start of CPB with a preserved reduction by trend at all other time points. Ischemia/reperfusion led to decreased glucose levels. Application of EVL significantly increased glucose levels after reperfusion. In addition, potassium levels were significantly lower in EVL-treated animals at the end of reperfusion. Immunoblotting revealed increased S6 levels after CPB. EVL decreased phosphorylation of S6 in the heart and kidney, which indicates an inhibition of mTOR pathway. Moreover, EVL significantly modified phosphorylation of AKT, while decreasing IL2, IL6, RANTES, and TNFα (n = 6). Preventive application of EVL may modulate inflammation by inhibition of mammalian target of rapamycin (mTOR) pathway and reduction of proinflammatory cytokines. This may be beneficial to evade SIRS-related morbidities after CPB.

Impact of cardiopulmonary bypass surgery on cytokines in epicardial adipose tissue: comparison with subcutaneous fat

BACKGROUND

Cardiac surgery and cardiopulmonary bypass (CPB) have been shown to stimulate a systemic inflammatory response which has been associated with adverse postoperative outcomes. Adipose tissue, both epicardial (EAT) and subcutaneous (SAT), is a known source of inflammatory cytokines, but its role in the pathophysiology of surgery- and CPB-induced systemic inflammatory response has not been fully elucidated. Therefore, we conducted a study to establish levels of selected cytokines in EAT and SAT prior to and after surgery with CPB.

METHODS

Adipose tissue samples were obtained from patients undergoing planned cardiac surgery on CPB. Samples from EAT and SAT were collected before and immediately after CPB. Levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), adipocyte fatty acid-binding protein (AFABP), leptin and adiponectin were determined by ELISA, which were adjusted for a total concentration of proteins in the individual samples.

RESULTS

Samples from 77 patients (mean age 67.68 ± 11.5 years) were obtained and analysed. Leptin, adiponectin, TNF-α and AFABP were shown to decrease their concentrations statistically significantly in the EAT after CPB while no statistically significant drop was observed in the SAT. On the contrary, IL-6 showed only a slight and statistically insignificant decrease in the EAT after CPB and it was in the SAT where a statistically significant drop was observed.

DISCUSSION

One of the most relevant findings of this study was the marked decrease in EAT levels of TNF-α, AFABP, leptin and adiponectin after the CPB termination. Our results suggest that EAT might serve as a pool of cytokines which are released into the circulation in reaction to surgery with CPB. Should these novel findings be confirmed, new strategies to assess and possibly reduce EAT contribution on adverse outcomes of cardiac surgery may be developed.

Two decades of off-pump coronary artery bypass surgery: Harefield experience

The morbidity and mortality associated with conventional coronary artery bypass grafting (CABG) attributed to invasiveness of cardiopulmonary bypass (CPB) has been well documented. Recognition of this invasiveness with a focus centered on abolishing, or at least reducing the CPB associated morbidity and mortality led to the resurgence of off-pump coronary artery bypass (OPCAB) surgery nearly two decades ago. At about the same time, OPCAB was adopted at Harefield hospital partly as an institutional drive to promote innovation and partly as a strategy to improve outcomes. What was deemed as a challenging technique initially and practiced by a single surgeon has now become a valid substitute to conventional CABG for achieving complete myocardial revascularization. This strategy now accounts for more than 50% of all coronary artery surgery operations at Harefield hospital and is systematically used to treat all coronary anatomies; achieve complete revascularization by accessing all territories subtended by main coronary arteries; and accomplish equivalent quality grafts without restriction in vascular conduit usage. This review article provides an overview of the evolution of OPCAB surgery at an institution with a well-established OPCAB program confirming that as surgeons' experience matures, OPCAB surgery permits safe and effective total myocardial revascularization in virtually all patients with multivessel coronary artery disease.

Changes in total plasma and serum N-glycome composition and patient-controlled analgesia after major abdominal surgery

Systemic inflammation participates to the complex healing process occurring after major surgery, thus directly affecting the surgical outcome and patient recovery. Total plasma N-glycome might be an indicator of inflammation after major surgery, as well as an anti-inflammatory therapy response marker, since protein glycosylation plays an essential role in the inflammatory cascade. Therefore, we assessed the effects of surgery on the total plasma N-glycome and the association with self-administration of postoperative morphine in two cohorts of patients that underwent major abdominal surgery. We found that plasma N-glycome undergoes significant changes one day after surgery and intensifies one day later, thus indicating a systemic physiological response. In particular, we observed the increase of bisialylated biantennary glycan, A2G2S[3,6]2, 12 hours after surgery, which progressively increased until 48 postoperative hours. Most changes occurred 24 hours after surgery with the decrease of most core-fucosylated biantennary structures, as well as the increase in sialylated tetraantennary and FA3G3S[3,3,3]3 structures. Moreover, we observed a progressive increase of sialylated triantennary and tetraantennary structures two days after surgery, with a concomitant decrease of the structures containing bisecting N-acetylglucosamine along with bi- and trisialylated triantennary glycans. We did not find any statistically significant association between morphine consumption and plasma N-glycome.

Effects of Low-dose Selenium on the Inflammatory Response in Coronary Artery Bypass Graft Surgery: A Clinical Trial

Background

Coronary artery bypass graft (CABG) surgery with cardiopulmonary bypass (CPB) triggers an inflammatory reaction, leading to the development of myocardial damage and dysfunction. It is suggested that selenium (Se), an essential trace element, has a protective role against oxidative stress. Decreased intraoperative Se levels might be an independent predictive factor for postoperative multiorgan failure. In spite of its proposed advantages, however, the optimal timing and dosage are not well known.

Objectives

To determine whether 600 µg of intravenous Se administration before induction of anesthesia for CABG surgery could attenuate inflammatory reactions in an Iranian population.

Methods

This randomized triple-blind clinical trial took place in the department of cardiac surgery of an academic hospital affiliated with Guilan University of Medical Sciences (GUMS) from May 2015 to September 2015. Eighty-eight eligible patients scheduled for elective on-pump CABG surgery were divided into two groups using randomized fixed quadripartite blocks. They received either an intravenous bolus of 600 µg Se before induction of anesthesia, or normal saline as a placebo. We had four measurement time-points: just before induction of anesthesia (T0), immediately after the end of CPB (T1), 24 hours after surgery (T2), and 48 hours after surgery (T3). Interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) serum levels were measured using the enzyme-linked immunosorbent assay (ELISA).

Results

Data from a total of 81 patients were analyzed: group S (n = 41) and group C (n = 40). There was no significant difference between the two groups with regard to baseline characteristics. In both groups, CPB caused markedly increased IL-6, TNF-α, and CRP plasma concentrations compared with baseline (P = 0.0001). However, the pattern of changes was not significantly different between group S (P = 0.068) and group C (P = 0.26). The IL-6 and TNF-α change trends were significant in each group (P=0.0001). However, comparing the two groups showed no significant difference. With regard to IL-6, there was no significant difference between the two groups at the time-points of T1 (P = 0.34), T2 (P = 0.17), and T3 (P = 0.056), and the same was found for TNF-α at T1 (P = 0.34), T2 (P = 0.17), and T3 (P = 0.056). With regard to CRP, the trend of the changes was significant in each group (P = 0.0001). However, comparing two groups showed a borderline significant difference between them at T1 (P = 0.039), but not at T2 (P = 0.075) or T3 (P = 0.11).

Conclusions

This study revealed that the administration of 600 μg of intravenous Se immediately before induction of anesthesia was safe, but when compared to a placebo, no predominant clinical effects or modifications in the systemic inflammatory response induced by on-pump CABG were observed.

Similarity of coagulation and inflammation despite different surgical revascularization strategies – a prospective randomized trial

Background:

Supposedly, minimized extracorporeal circulation or off-pump revascularization as alternatives to conventional extracorporeal circulation (ONCAB) reduce inflammation and coagulation disturbances.

Methods:

One hundred and twenty coronary artery bypass graft (CABG) patients were prospectively randomized for three surgical techniques. Coagulation and inflammation markers were measured up to 72 hours postoperatively.

Results:

Coagulation factors I, II, V, X, antithrombin III and C-reactive protein did not differ perioperatively between the groups and increased, as did several other markers, 12 to 72 hours postoperatively. Compared to its alternatives, ONCAB showed the most obvious transient increase in thrombin-antithrombin complexes (p<0.0001), D-dimers (p=0.0059), tissue factor pathway inhibitor (p=0.0005), factor VIII (p=0.0041) and tumor necrosis factor α (p=0.0300) during the operation and up to 12 hours postoperatively. Furthermore, ONCAB generated lower leukocyte and platelet counts and higher values of soluble P-selectin and soluble intercellular adhesion molecule 1 at some time points.

Conclusions:

With similarity in pivot coagulation factors, a specific detrimental influence of ONCAB on common coagulation pathways was excluded. Higher perioperative concentrations of products from the coagulation cascade most likely indicate activation of pericardial blood – recirculated only in ONCAB. Furthermore, with only temporary differences in markers of inflammation, the alternatives to ONCAB altogether were without advantage at 72 hours postoperatively. In the general answer to surgical trauma, the part of modern extracorporeal circulation is possibly overestimated. The study is registered at the German Clinical Trial Registry. Registration number DRKS00007580. URL: https://drks-neu.uniklinik-freiburg.de/drks_web/ URL: http://apps.who.int/trialsearch/

Optimizing Prophylactic Antibiotic Practice for Cardiothoracic Surgery by Pharmacists' Effects

Pharmacists' role may be ideal for improving rationality of drug prescribing practice. We aimed to study the impact of multifaceted pharmacist interventions on antibiotic prophylaxis in patients undergoing clean or clean-contaminated operations in cardiothoracic department. A pre-test-post-test quasiexperimental study was conducted in a cardiothoracic ward at a tertiary teaching hospital in Suzhou, China. Patients admitted to the ward were collected as baseline group (2011.7-2012.12) and intervention group (2013.7-2014.12), respectively. The criteria of prophylaxis antibiotic utilization were established on the basis of the published guidelines and official documents. During the intervention phase, a dedicated pharmacist was assigned and multifaceted interventions were implemented in the ward. Then we compared the differences in antibiotic utilization, bacterial resistance, clinical and economic outcomes between the 2 groups. Furthermore, patients were collected after the intervention (2015.1-2015.6) to evaluate the sustained effects of pharmacist interventions. 412 and 551 patients were included in the baseline and intervention groups, while 156 patients in postintervention group, respectively. Compared with baseline group, a significant increase was found in the proportion of antibiotic prophylaxis, the proportion of rational antibiotic selection, the proportion of suitable prophylactic antibiotic duration, and the proportion of suitable timing of administration of the first preoperative dose (P < 0.001). Meanwhile, a significant reduction was seen in the rate of unnecessary replacement of antibiotics and the rate of unnecessary combinations (P < 0.001). Besides, pharmacist intervention resulted in favorable outcomes with significantly decreased rates of surgical site infections, prophylactic antibiotic cost, and significantly shortened length of stay (P < 0.05). Furthermore, there were also significant decreases of the rates of antibiotic resistant enterobacter cloacae, klebsiella pneumonia, and staphylococcus aureus (P < 0.05). Moreover, the effects were sustained after discontinuation of the active interventions, as shown in prophylactic antibiotic utilization data. Pharmacist interventions in cardiothoracic surgery result in a high adherence to evidence-based treatment guidelines and a profound culture change in drug prescribing with favorable outcomes. The effects of pharmacist intervention are sustained and the role of pharmacists is emphasized for rational medication and optimal outcomes in clinical treatment.

Hidrocortisona reduz as concentrações séricas dos biomarcadores inflamatórios séricos em pacientes submetidos a endarterectomia de carótida

ResumoContextoA hidrocortisona pode reduzir a concentração dos biomarcadores inflamatórios séricos e teciduais.ObjetivoAnalisar a atividade inflamatória da proteína C-reativa ultrassensível (PCR-US), do fator de necrose tumoral (FNT)-alfa e do fator de crescimento do endotélio vascular (FCEV) séricos e teciduais, mediante administração intraoperatória de hidrocortisona, após endarterectomia de artéria carótida (EAC).MétodoVinte e dois pacientes foram divididos em Grupo Controle (5 assintomáticos e 6 sintomáticos) – não foi administrada hidrocortisona – e Grupo 1 (4 assintomáticos e 7 sintomáticos) – foram administrados 500 mg intravenoso de hidrocortisona. O PCR-US, o FNT-alfa e o FCEV séricos foram dosados no pré-operatório e em 1 hora, 6 horas e 24 horas após a EAC. Na placa carotídea, mensuramos os níveis de FNT-alfa e FCEV.ResultadosO grupo 1 exibiu menor concentração sérica de FNT-alfa em 1 hora (p=0,031), 6 horas (p=0,015) e 24 horas (p=0,017) após a EAC, e menor concentração de FCEV em 1 hora (p=0,006) e 6 horas (p=0,005) após a EAC, em relação ao grupo controle. Os pacientes sintomáticos do grupo 1 exibiram menor concentração de FNT-alfa em 1 hora e 6 horas após a EAC, e menor concentração de FCEV em 1 hora após a EAC, em relação ao grupo controle. Não houve diferença estatística entre as concentrações teciduais de FNT-alfa e FCEV entre o grupo controle e o grupo 1.ConclusãoA hidrocortisona reduz as concentrações séricas pós-operatórias de FNT-alfa e FCEV, em especial nos sintomáticos; porém, não reduz os níveis teciduais destes biomarcadores.

Hydrocortisone supresses inflammatory activity of metalloproteinase-8 in carotid plaque

Objective

Matrix metalloproteinases are inflammatory biomarkers involved in carotid plaque instability. Our objective was to analyze the inflammatory activity of plasma and carotid plaque MMP-8 and MMP-9 after intravenous administration of hydrocortisone.

Methods

The study included 22 patients with stenosis ≥ 70% in the carotid artery (11 symptomatic and 11 asymptomatic) who underwent carotid endarterectomy. The patients were divided into two groups: Control Group - hydrocortisone was not administered, and Group 1 - 500 mg intravenous hydrocortisone was administered during anesthetic induction. Plasma levels of MMP-8 and MMP-9 were measured preoperatively (24 hours before carotid endarterectomy) and at 1 hour, 6 hours and 24 hours after carotid endarterectomy. In carotid plaque, tissue levels of MMP-8 and MMP-9 were measured.

Results

Group 1 showed increased serum levels of MMP- 8 (994.28 pg/ml and 408.54 pg/ml, respectively; P=0.045) and MMP-9 (106,656.34 and 42,807.69 respectively; P=0.014) at 1 hour after carotid endarterectomy compared to the control group. Symptomatic patients in Group 1 exhibited lower tissue concentration of MMP-8 in comparison to the control group (143.89 pg/ml and 1317.36 respectively; P=0.003). There was a correlation between preoperative MMP-9 levels and tissue concentrations of MMP-8 (P=0.042) and MMP-9 (P=0.019) between symptomatic patients in the control group.

Conclusion

Hydrocortisone reduces the concentration of MMP- 8 in carotid plaque, especially in symptomatic patients. There was an association between systemic and tissue inflammation.

Usefulness of colchicine to reduce perioperative myocardial damage in patients who underwent on-pump coronary artery bypass grafting

The objective of the present study was to test whether a perioperative course of colchicine, in patients who underwent standard coronary artery bypass grafting, would result in reduced postoperative increase of myocardial injury biomarker levels. Patients were prospectively randomized to colchicine or placebo starting 48 hours before scheduled coronary artery bypass grafting and for 8 days thereafter (0.5 mg twice daily). The primary outcome parameter was maximal high-sensitivity troponin T (hsTnT) concentration within 48 hours after surgery. Secondary outcome measures were maximal creatine kinase-myocardial brain fraction (CK-MB) levels and area under the curve (AUC) of hsTnT and CK-MB concentrations; 59 patients were included. Maximal hsTnT was 616 pg/ml (396 to 986) in the colchicine group versus 1,613 pg/ml (732 to 2,587) in controls (p = 0.002). Maximal CK-MB was 44.6 ng/ml (36.6 to 68.8) and 93.0 ng/ml (48.0 to 182.3), respectively (p = 0.002). The median AUC for hsTnT was 40,755 pg h/ml (20,868 to 79,176) in controls versus 20,363 pg h/ml (13,891 to 31,661) in the colchicine group (p = 0.002). AUCs for CK-MB were 2,552 ng h/ml (1,564 to 4,791) in controls and 1,586 ng h/ml (1,159 to 2,073) in the colchicine group (p = 0.003). The main complaints associated with colchicine were, as expected, gastrointestinal, with 5 patients (16.7%) in the colchicine group reporting diarrhea versus 1 control (3.4%) (p = 0.195). In conclusion, a short perioperative course of colchicine was effective in attenuating postoperative increases of hsTnT and CK-MB compared with placebo. This finding, which needs confirmation in a larger clinical trial powered to assess clinical endpoints, suggests a potential role for this agent in reducing cardiac surgery-related myocardial damage.

Biocompatibility of cardiopulmonary bypass circuit with new polymer Senko E-Ternal CoatingTM

Objective:

The aim of this study was to compare the biocompatibility of a new Senko E-Ternal coating (SEC) for cardiopulmonary bypass (CPB) circuits with the well-established poly-2-methoxyethyl acrylate (PMEA) coating.

Methods:

Forty patients undergoing aortic valve replacement were randomly assigned to either an SEC-coated group (n = 20) or a PMEA-coated group (n = 20). Clinical data and the following markers were analyzed: platelet count, platelet factor (PF) 4, fibrinogen, fibrinogen degradation products (FDPs), antithrombin III (AT III), thrombin-antithrombin complex (TAT), plasminogen, complement hemolytic activity (CH50), complement 3 (C3) and interleukin-6 (IL-6). Blood samples were obtained at five time points in both groups.

Results:

CPB time, aortic cross-clamp time and blood loss and transfusion were similar in both groups. There were no significant differences between the groups in terms of platelet count, PF4 and all coagulation and fibrinolytic parameters (FDP, AT III, TAT, and plasminogen) at any time points. Inflammatory markers (CH50, C3 and IL-6) were also similar in both groups at all time points.

Conclusions:

The SEC-coated circuit demonstrated equivalent biocompatibility to the PMEA-coated circuit. SEC-coated circuits are, therefore, favorably comparable to PMEA-coated circuits for clinical use in CPB.

Aortic valve replacement through J-shaped partial upper sternotomy

The introduction of minimally invasive techniques in general surgery, in the late 1980s, influenced cardiac surgery as well. This led to the emergence of several minimal access approaches for aortic valve replacement (AVR). Currently, the upper partial sternotomy with unilateral J-shaped extension to the right through the fourth intercostal space is the most popular minimal access approach. This approach offers the comfort factor of sternotomy, improved cosmetic result, preserved respiratory mechanics, and last but not the least cost saving as no new equipment is required. On the other hand, inability to visualize the whole heart, adequately de-air the left heart, and failure to apply epicardial pacing wires are some of the perceived disadvantages of this approach. This article provides a comprehensive review of the indications, contraindications, technical aspects, outcomes, advantages and disadvantages of AVR through J-shaped partial upper sternotomy.

Changes in IgG and total plasma protein glycomes in acute systemic inflammation

Recovery after cardiac surgery is a complex process that has to compensate for both individual variability and extensive tissue damage in the context of systemic inflammation. Protein glycosylation is essential in many steps of the inflammatory cascade, but due to technological limitations the role of individual variation in glycosylation in systemic inflammation has not been addressed until now. We analysed composition of the total plasma and IgG N-glycomes in 107 patients undergoing cardiac surgery. In nearly all individuals plasma N-glycome underwent the same pattern of changes in the first 72 h, revealing a general mechanism of glycosylation changes. To the contrary, changes in the IgG glycome were very individualized. Bi-clustering analysis revealed the existence of four distinct patterns of changes. One of them, characterized by a rapid increase in galactosylated glycoforms, was associated with nearly double mortality risk measured by EuroSCORE II. Our results indicate that individual variation in IgG glycosylation changes during acute systemic inflammation associates with increased mortality risk and indicates new avenues for the development of personalized diagnostic and therapeutic approach.

An exploratory study of the patients' sleep patterns and inflammatory response following cardiopulmonary bypass (CPB)

AIMS AND OBJECTIVES

To describe sleep patterns and inflammatory response postCPB, determine sleep pattern changes and inflammatory response over time and explore relationships between sleep and biomarkers of stress and inflammation.

BACKGROUND

Despite the numerous citations of the role of sleep in restoration and health maintenance, a paucity of research exists about this phenomenon in patients undergoing CPB. Specifically, there is no research that has explored correlations between sleep patterns and systemic inflammatory response in adult cardiac surgery patients.

DESIGN

Exploratory, repeated-measures, correlational study.

METHOD

Subjects were recruited from a Midwestern urban hospital. Of the 25 eligible subjects, 16 males and four females completed the study. Wrist actigraphy was used to measure sleep variables. Salivary cortisol and C-reactive protein (C-RP) levels were measured daily. Data were collected during postoperative nights/days 1 through 4 (T1-T4).

RESULTS

Subjects' sleep onset latency (SOL) median scores (0 minute) were within normal range across time periods, whereas median scores for wake after sleep onset (WASO > 270 minutes), sleep fragmentation index (SFI >51%), total sleep time (<153 minutes) and sleep efficiency index (SEI <36%) fell outside the normal ranges. Changes in the median sleep scores over time, however, were not significant at p > 0·05. Median cortisol levels were within normal range (0·3-0·8 μg/dl) from T1-T4, but the C-RP level peaked at T2 (median = 2370 pg/ml). Strong correlations were found: (1) between SFI-cortisol (rs = 0·82), C-RP (rs = 0·65) - WBC (rs = 0·69); (2) between SEI-C-RP (rs = 0·58); (3) between WASO-WBC (rs = 0·48), WASO and cross-clamp time (rs = 0·50); and (4) between SOL-age (rs = -0·55) at p < 0·05.

CONCLUSIONS

Subjects were severely sleep-deprived with inflammatory response exaggerations warranting further investigations using larger sample sizes.

RELEVANCE TO CLINICAL PRACTICE

This study offers a foundation for developing a conceptual model explaining mechanisms of sleep disturbance and inflammatory response postCPB. This knowledge is crucial for testing sleep-promoting interventions to modulate inflammatory responses essential for preventing complications, and restoring health.

Kinetics of procalcitonin and C-reactive protein and the relationship to postoperative infection in young infants undergoing cardiovascular surgery

BACKGROUND

The utility of procalcitonin (PCT) and C-reactive protein (CRP) as infectious biomarkers following infant cardiothoracic surgery is not well defined.

METHODS

We designed a prospective cohort study to evaluate PCT and CRP after infant cardiothoracic surgery. PCT and CRP were drawn preoperatively and 24/72 h postoperation or daily in delayed sternal closure patients. Presence of infection within 10 d of surgery, vasoactive-inotropic scores at 24 and 72 h, and length of intubation, intensive care unit stay, and hospital stay were documented.

RESULTS

PCT and CRP were elevated at 24 h. PCT then decreased while CRP increased in patients undergoing delayed sternal closure or cardiopulmonary bypass. In the delayed sternal closure group, PCT was significantly higher on postoperative days 2-5 in patients who ultimately developed infection. Higher PCT was independently associated with increased vasoactive-inotropic score at 72 h. CRP did not correlate with infection or postoperative support.

CONCLUSION

PCT rises after cardiothoracic surgery in infants but decreases by 72 h while CRP remains elevated. Sternal closure may affect CRP but not PCT. PCT is independently associated with circulatory support requirements at 72 h postoperation and with development of infection. PCT may have greater utility as a biomarker in this population.

The role of different anesthetic techniques in altering the stress response during cardiac surgery in children: a prospective, double-blinded, and randomized study

OBJECTIVES

Our goal was to evaluate the role of three anesthetic techniques in altering the stress response in children undergoing surgery for repair of congenital heart diseases utilizing cardiopulmonary bypass in the setting of fast tracking or early tracheal extubation. Furthermore, we wanted to evaluate the correlation between blunting the stress response and the perioperative clinical outcomes.

DESIGN

Prospective, randomized, double-blinded study.

SETTING

Single center from December 2008 to May of 2011.

PATIENTS

Forty-eight subjects (low-dose fentanyl plus placebo, n = 16; high-dose fentanyl plus placebo, n = 17; low-dose fentanyl plus dexmedetomidine, n = 15) were studied between ages 30 days to 3 years old who were scheduled to undergo repair for a ventricular septal defect, atrioventricular septal defect, or Tetralogy of Fallot.

METHODS

Children undergoing surgical repair of congenital heart disease were randomized to receive low-dose fentanyl (10 mcg/kg; low-dose fentanyl), high-dose fentanyl (25mcg/kg; high-dose fentanyl), or low-dose fentanyl plus dexmedetomidine (as a 1 mcg/kg loading dose followed by infusion at 0.5mcg/kg/hr until separation from cardiopulmonary bypass. In addition, patients received a volatile anesthetic agent as needed to maintain hemodynamic stability. Blood samples were tested for metabolic, hormonal and cytokine markers at baseline, after sternotomy, after the start of cardiopulmonary bypass, at the end of the procedure and at 24 hours postoperatively.

MEASUREMENTS AND MAIN RESULTS

Forty-eight subjects (low-dose fentanyl plus placebo, n = 16; high-dose fentanyl plus placebo, n = 17; low-dose fentanyl plus dexmedetomidine, n = 15) were studied. Subjects in the low-dose fentanyl plus placebo group had significantly higher levels of adrenocorticotropic hormone, cortisol, glucose, lactate, and epinephrine during the study period. The lowest levels of stress markers were seen in the high-dose fentanyl plus placebo group both over time (adrenocorticotropic hormone, p= 0.01; glucose, p = 0.007) and at individual time points (cortisol and lactate at the end of surgery, epinephrine poststernotomy; p < 0.05). Subjects in the low-dose fentanyl plus dexmedetomidine group had lower lactate levels at the end of surgery compared with the low-dose fentanyl plus placebo group (p < 0.05). Although there were no statistically significant differences in plasma cytokine levels between the three groups, the low-dose fentanyl plus placebo group had significantly higher interleukin-6:interleukin-10 ratio at 24 hours postoperatively (p < 0.0001). In addition, when compared with the low-dose fentanyl plus placebo group, the low-dose fentanyl plus dexmedetomidine group showed a lower norepinephrine level from baseline at poststernotomy, after the start of cardiopulmonary bypass, and at the end of surgery (p ≤ 0.05). Subjects in the low-dose fentanyl plus placebo group had more postoperative narcotic requirement (p = 0.004), higher prothrombin time (p ≤ 0.03), and more postoperative chest tube output (p < 0.05). Success of fast tracking was not significantly different between groups (low-dose fentanyl plus placebo 75%, high-dose fentanyl plus placebo 82%, low-dose fentanyl plus dexmedetomidine 93%; p = 0.39).

CONCLUSIONS

The use of low-dose fentanyl was associated with the greatest stress response, most coagulopathy, and highest transfusion requirement among our cohorts. Higher dose fentanyl demonstrated more favorable blunting of the stress response. When compared with low-dose fentanyl alone, the addition of dexmedetomidine improved the blunting of the stress response, while achieving better postoperative pain control.

Risk factors for postoperative hypoxemia in patients undergoing Stanford A aortic dissection surgery

Background

The purpose of this study is to identify the risk factors for postoperative hypoxemia in patients with Stanford A aortic dissection surgery and their relation to clinical outcomes.

Methods

Clinical records of 186 patients with postoperative hypoxemia in Stanford A aortic dissection were analyzed retrospectively. The patients were divided into two groups by postoperative oxygen fraction (PaO2/FiO2):hypoxemia group (N=92) and non-hypoxemia group (N=94).

Results

We found that the incidence of postoperative hypoxemia was 49.5%. Statistical analysis by t-test and χ2 indicated that acute onset of the aortic dissection (p=0.000), preoperative oxygen fraction (PaO2/FiO2) ≤200 mmHg(p=0.000), body mass index (p=0.008), circulatory arrest (CA) time (p=0.000) and transfusion more than 3000 ml(p=0.000) were significantly associated with postoperative hypoxemia. Multiple logistic regression analysis showed that preoperative hypoxemia, CA time and transfusion more than 3000 ml were independently associated with postoperative hypoxemia in Stanford A aortic dissection.

Conclusion

Our results suggest that postoperative hypoxemia is a common complication in patients treated by Stanford A aortic dissection surgery. Preoperative oxygen fraction lower than 200 mmHg, longer CA time and transfusion more than 3000 ml are predictors of postoperative hypoxemia in Stanford A aortic dissection.

Cardioprotective effect of ghrelin in cardiopulmonary bypass involves a reduction in inflammatory response

Background

Ghrelin has been reported to protect the cardiovascular system; however, the cardioprotective effect of ghrelin against cardiopulmonary bypass (CPB) induced myocardial injury are unclear. In this study, the protective effect of ghrelin on CPB induced myocardial injury and the underlying mechanisms were investigated.

Methods and Results

Adult male rats were subjected to CPB and randomly to receive vehicle (n = 8), ghrelin (n = 8), ghrelin plus [D-Lys3]-GHRP-6, a GHSR-1a inhibitor (n = 8), or ghrelin plus wortmannin, a phosphoinositide 3′-kinase (PI3K) inhibitor (n = 8). In vitro study was performed on cultured cardiomyocytes subjected to simulated cardiopulmonary bypass (SCPB). Ghrelin attenuated the inflammatory response, as evidenced by reduced induction of TNF-α, IL-6 and myocardial myeloperoxidase activity and concurrent reduction in apoptosis, oxidative stress, and levels of myocardial injury markers following CPB. Moreover, ghrelin significantly increased cardiac function after CPB. In cultured cardiomyocytes subjected to simulated CPB, ghrelin increased cell viability and decreased the percentage of apoptotic myocytes. Inhibition of ghrelin downstream signaling blocked the cardioprotective effects both in vivo and vitro.

Conclusions

Ghrelin could provide an effective approach to the attenuation of CPB induced myocardial injury. The cardioprotective effects elicited by ghrelin may contribute to the inhibition of inflammatory response through the Akt-activated pathway.

CD62L (L-selectin) shedding for assessment of perioperative immune sensitivity in patients undergoing cardiac surgery with cardiopulmonary bypass

OBJECTIVE

To investigate the suitability of blood granulocyte and monocyte sensitivity, as measured by the quantity of different agonists required to induce CD62L shedding, for assessment of perioperative immune changes in patients undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

Patients scheduled for aortocoronary bypass grafting or for valve surgery were included in this prospective observational study. Blood samples were drawn before anesthesia induction, directly after surgery and 48 hours after anesthesia induction. We determined the concentration of two different inflammatory stimuli--lipoteichoic acid (LTA) and tumor necrosis factor alpha (TNF)--required to induce shedding of 50% of surface CD62L from blood granulocytes and monocytes. In parallel monocyte surface human leukocyte antigen (HLA)-DR, and plasma interleukin (IL)-8, soluble (s)CD62L, soluble (s)Toll-like receptor (TLR)-2 and ADAM17 quantification were used to illustrate perioperative immunomodulation.

RESULTS

25 patients were enrolled. Blood granulocytes and monocytes showed decreased sensitivity to the TLR 2/6 agonist Staphylococcus aureus LTA immediately after surgery (p = 0.001 and p = 0.004 respectively). In contrast, granulocytes (p = 0.01), but not monocytes (p = 0.057) displayed a decreased postoperative sensitivity to TNF. We confirmed the presence of a systemic inflammatory response and a decreased immune sensitivity in the post-surgical period by measuring significant increases in the perioperative plasma concentration of IL-8 (p ≤ 0.001) and sTLR (p = 0.004), and decreases in monocyte HLA-DR (p<0.001), plasma sCD62L (p ≤ 0.001). In contrast, ADAM17 plasma levels did not show significant differences over the observation period (p = 0.401).

CONCLUSIONS

Monitoring granulocyte and monocyte sensitivity using the "CD62L shedding assay" in the perioperative period in cardiac surgical patients treated with the use of cardiopulmonary bypass reveals common changes in sensitivity to TLR2/6 ligands and to TNF stimulus. Further long-term follow-up studies will address the predictive value of these observations for clinical purposes.

Remote ischemic preconditioning regulates HIF-1α levels, apoptosis and inflammation in heart tissue of cardiosurgical patients: a pilot experimental study

Transient episodes of ischemia in a remote organ (remote ischemic preconditioning, RIPC) bears the potential to attenuate myocardial injury, but the underlying mechanisms are only poorly understood. In the pilot experimental study presented we investigated cellular and molecular effects of RIPC in heart tissue of cardiosurgical patients with cardiopulmonary bypass (CPB) and focussed on apoptotic events, local and systemic inflammation as well as the regulation of the hypoxia induced factor-1α (HIF-1α). RIPC was induced by four 5-min cycles of transient upper limb ischemia/reperfusion using a blood-pressure cuff. Right atrial tissue and serum were obtained from patients receiving RIPC (N = 32) and control patients (N = 29) before and after CPB. RIPC patients showed reduced troponin T serum concentrations in the first 48 h after surgery (P < 0.05 vs. control) indicating cardioprotective effects of RIPC. Samples from RIPC patients that were collected before CPB contained significantly increased amounts of HIF-1α and procaspase-3 (HIF-1α: P < 0.05 vs. control, procaspase-3: P < 0.05 vs. control), whereas activities of caspases 3 and 7 were by trend reduced. Samples from RIPC patients that were taken after CPB showed an increased activity of myeloperoxidase (P < 0.05 vs. control; P < 0.05 vs. RIPC before CPB) as well as elevated tissue concentrations of the interleukin (IL)-1β (P < 0.05 vs. RIPC before CPB). Serum levels of IL-8, IL-1β and TNFα were significantly increased in RIPC patients before CPB (P < 0.05 vs. control before CPB). In summary, RIPC regulates HIF-1α levels, apoptosis and inflammation in the myocardium of cardiosurgical patients and leads to increased concentrations of circulating cytokines.

Alkaline phosphatase activity after cardiothoracic surgery in infants and correlation with post-operative support and inflammation: a prospective cohort study

Introduction

Limited evidence suggests that serum alkaline phosphatase activity may decrease after cardiac surgery in adults and children. The importance of this finding is not known. Recent studies, however, have identified a potential role for alkaline phosphatase as modulator of inflammation in multiple settings, including during adult cardiopulmonary bypass. We sought to describe the change in alkaline phosphatase activity after cardiothoracic surgery in infants and to assess for a correlation with intensity and duration of post-operative support, markers of inflammation, and short-term clinical outcomes.

Methods

Sub-analysis of a prospective observational study on the kinetics of procalcitonin in 70 infants (≤90 days old) undergoing cardiothoracic surgery. Subjects were grouped based on the use of cardiopulmonary bypass and delayed sternal closure. Alkaline phosphatase, procalcitonin, and C-reactive protein (CRP) levels were obtained pre-operation and on post-operative day 1. Mean change in alkaline phosphatase activity was determined in each surgical group. Generalized linear modeling and logistic regression were employed to assess for associations between post-operative alkaline phosphatase activity and post-operative support, inflammation, and short term outcomes. Primary endpoints were vasoactive-inotropic score at 24 hours and length of intubation. Secondary endpoints included procalcitonin/CRP levels on post-operative day 1, length of hospital stay, and cardiac arrest or death.

Results

Mean decrease in alkaline phosphatase was 30 U/L (p = 0.01) in the non-bypass group, 114 U/L (p<0.0001) in the bypass group, and 94 U/L (p<0.0001) in the delayed sternal closure group. On multivariate analysis, each 10 U/L decrease in alkaline phosphatase activity on post-operative day 1 was independently associated with an increase in vasoactive-inotropic score by 0.7 (p<0.0001), intubation time by 6% (p<0.05), hospital stay by 5% (p<0.05), and procalcitonin by 14% (P<0.01), with a trend towards increased odds of cardiac arrest or death (OR 1.3; p = 0.06). Post-operative alkaline phosphatase activity was not associated with CRP (p = 0.7).

Conclusions

Alkaline phosphatase activity decreases after cardiothoracic surgery in infants. Low post-operative alkaline phosphatase activity is independently associated with increased procalcitonin, increased vasoactive/inotropic support, prolonged intubation time, and prolonged hospital stay. Alkaline phosphatase may serve as a biomarker and potential modulator of post-operative support and inflammation following cardiothoracic surgery in infants.

Risk assessment using a novel score to predict anastomotic leak and major complications after oesophageal resection

BACKGROUND

Oesophagectomy is associated with significant morbidity and mortality. A simple score to define a patient's risk of developing major complications would be beneficial.

METHODS

Patients who underwent upper gastrointestinal resections with an oesophageal anastomosis between 2005 and 2010 were reviewed and formed the development dataset with resections performed in 2011 forming a prospective validation dataset. The association between post-operative C-reactive protein (CRP), white cell count (WCC) and albumin levels with anastomotic leak (AL) or major complication including death using the Clavien-Dindo (CD) classification were analysed by receiver operating characteristic curves. After multivariate analysis, from the development dataset, these factors were combined to create a novel score which was subsequently tested on the validation dataset.

RESULTS

Two hundred fifty-eight patients were assessed to develop the score. Sixty-three patients (25%) developed a major complication, and there were seven (2.7%) in-patient deaths. Twenty-six (10%) patients were diagnosed with AL at median post-operative day 7 (range: 5-15). CRP (p = 0.002), WCC (p < 0.0001) and albumin (p = 0.001) were predictors of AL. Combining these markers improved prediction of AL (NUn score > 10: sensitivity 95%, specificity 49%, diagnostic accuracy 0.801 (95% confidence interval: 0.692-0.909, p < 0.0001)). The validation dataset confirmed these findings (NUn score > 10: sensitivity 100%, specificity 57%, diagnostic accuracy 0.879 (95% CI 0.763-0.994, p = 0.014)) and a major complication or death (NUn > 10: sensitivity 89%, specificity 63%, diagnostic accuracy 0.856 (95% CI 0.709-1, p = 0.001)).

CONCLUSIONS

Blood-borne markers of the systemic inflammatory response are predictors of AL and major complications after oesophageal resection. When combined they may categorise a patient's risk of developing a serious complication with higher sensitivity and specificity.

Cardioprotection during cardiac surgery

Coronary heart disease (CHD) is the leading cause of morbidity and mortality worldwide. For a large number of patients with CHD, coronary artery bypass graft (CABG) surgery remains the preferred strategy for coronary revascularization. Over the last 10 years, the number of high-risk patients undergoing CABG surgery has increased significantly, resulting in worse clinical outcomes in this patient group. This appears to be related to the ageing population, increased co-morbidities (such as diabetes, obesity, hypertension, stroke), concomitant valve disease, and advances in percutaneous coronary intervention which have resulted in patients with more complex coronary artery disease undergoing surgery. These high-risk patients are more susceptible to peri-operative myocardial injury and infarction (PMI), a major cause of which is acute global ischaemia/reperfusion injury arising from inadequate myocardial protection during CABG surgery. Therefore, novel therapeutic strategies are required to protect the heart in this high-risk patient group. In this article, we review the aetiology of PMI during CABG surgery, its diagnosis and clinical significance, and the endogenous and pharmacological therapeutic strategies available for preventing it. By improving cardioprotection during CABG surgery, we may be able to reduce PMI, preserve left ventricular systolic function, and reduce morbidity and mortality in these high-risk patients with CHD.

Cardioplegic strategies to protect the hypertrophic heart during cardiac surgery

Cardioplegic arrest and cardiopulmonary bypass are key triggers of myocardial injury during aortic valve surgery. Cardioplegic ischaemic arrest is associated with disruption to metabolic and ionic homeostasis in cardiomyocytes. These changes predispose the heart to reperfusion injury caused by elevated intracellular reactive oxygen species and calcium. Cardiopulmonary bypass is associated with an inflammatory response that can generate systemic oxidative stress which, in turn, provokes further damage to the heart. Techniques of myocardial protection are routinely applied to all hearts, irrespective of their pathology, although different cardiomypathies respond differently to ischaemia and reperfusion injury. In particular, the efficacy of cardioprotective interventions used to protect the hypertrophic heart in patients with aortic valve disease remains controversial. This review will describe key cellular changes in hypertrophy, response to ischaemia and reperfusion and cardioplegic arrest and highlight the importance of optimising cardioprotective strategies to suit hypertrophic hearts.

Preoperative inhalation of milrinone attenuates inflammation in patients undergoing cardiac surgery with cardiopulmonary bypass

OBJECTIVES

The purpose of this study was to evaluate the effect of preoperative inhalation of milrinone on cardiopulmonary bypass (CPB)-related inflammation.

SUBJECTS AND METHODS

A total of 30 patients undergoing cardiac surgery were recruited and randomized for preoperative inhalation of milrinone (Mil group) or normal saline (NS group), respectively. Each group had 15 patients. Their hemodynamic parameters were measured and blood samples were obtained longitudinally. The levels of serum interleukin (IL-6), tumor necrosis factor-α (TNF-α), and matrix metalloproteinase (MMP)-9 were determined by ELISA.

RESULTS

The levels of serum IL-6, TNF-α, and MMP-9 significantly increased at the end of cardiac surgery and remained high for 24 h in both groups of patients. However, the levels of proinflammatory cytokines at the end of cardiac surgery in the Mil group of patients were significantly lower than those of the NS group of patients.

CONCLUSIONS

Our data indicated that preoperative inhalation of milrinone significantly mitigated CPB-related inflammation.

Experimental research with synthetic copolymer-coated cardiopulmonary bypass circuits: inflammatory and thrombogenicity analysis

This study aimed to assess complement system activation and index of thrombogenicity and platelet aggregation between synthetic copolymer-coated cardiopulmonary bypass (CPB) circuit and conventional CPB circuit. Twenty-six pigs were equally divided into two groups--the conventional group and the coated group. They were placed on CPB for 90 min, and blood samples were collected at three different time points (T0, right before CPB establishment; T1, 45 min after starting CPB; and T2, 90 min after starting CPB) to measure total count of inflammatory cells (leukocytes, neutrophils, lymphocytes, and platelets) and serum levels of fraction C3 of complement system. Upon completion of the 90-min CPB, fragments of different compartments of the CPB circuit were taken for assessing index of thrombogenicity and platelet aggregation. There were no differences between both groups regarding total count of leukocytes, neutrophils, and lymphocytes; however, there was a lower count of platelets at T2 in the coated group (P = 0.020). The serum level of fraction C3 was lower in the coated group at T1 (P = 0.020) and T2 (P = 0.017). Higher index of thrombogenicity and platelet aggregation were detected in the conventional group (77% of the animals within the conventional group) than in the coated group (46% of the animals within the coated group). In conclusion, in heart surgery requiring CPB, the use of synthetic copolymer-coated CPB circuit may be useful to reduce complement system activation, as well as attenuating index of thrombogenicity and platelet aggregation.

Simvastatin attenuates cardiopulmonary bypass-induced myocardial inflammatory injury in rats by activating peroxisome proliferator-activated receptor γ

Statins have been shown to downregulate the systemic inflammatory response after cardiopulmonary bypass. However, the role of statins as anti-inflammatory agents in heart tissue remains unknown. The aim of this study was to test whether statin pretreatment attenuates local inflammatory cytokines production in heart and to explore whether the underlying mechanism involves peroxisome proliferator-activated receptor (PPAR) γ. A rat model of cardiopulmonary bypass was established. The animals were pretreated with simvastatin 5 mg/kg/day or 10 mg/kg/day for 7 days before operation. The serum concentration and myocardial level of tumor necrosis factor (TNF)-α, interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1 was evaluated by enzyme linked immunosorbent assay. The polymorphonuclear neutrophils accumulation in heart tissue was determined by myeloperoxidase activity assay. The activity of nuclear factor (NF)-κB and PPARγ in the heart was determined by electrophoretic mobility shift assay. The myocardial PPARγ expression was also examined by immunohistochemistry. The systemic and local TNF-α, IL-6 and MCP-1 were all significantly elevated after cardiopulmonary bypass. In contrast, simvastatin pretreatment significantly decreases the serum and myocardial expression level of above cytokines, myocardial myeloperoxidase activity and myocardial NF-κB activity. However, there was an evident increase in the activity and expression of PPARγ. In conclusion, simvastatin pretreatment not only attenuates acute systemic and local inflammatory response induced by cardiopulmonary bypass. The anti-inflammatory effect of simvastatin in myocardium may be partly related to the activation of PPARγ and inhibition of NF-κB.

Mini extracorporeal circuit cardiopulmonary bypass system: a review

Improved knowledge of the pathophysiological processes experienced in response to cardiopulmonary bypass has led to new developments in extracorporeal technology and understanding. The use of mini extracorporeal circuits (MECC) is rapidly expanding in clinical practice. The mini extracorporeal circuit differs by a greatly reduced tubing length and the number of components when compared with current circuit designs. The MECC is believed to offer potential benefits to the surgical patient by reducing the systemic inflammatory response that remains strongly implicated in post-operative organ dysfunction. We present a review of the available literature and find the MECC to show an acceptable safety profile with a reduction in post-operative complications and transfusion requirements and no evidence of any negative impairment to the surgeon, anaesthetist or perfusionist. The observed post-bypass inflammatory response is seen to be lower after MECC bypass and this is of clear clinical benefit.

Myocardial TLR4 is a determinant of neutrophil infiltration after global myocardial ischemia: mediating KC and MCP-1 expression induced by extracellular HSC70

Cardiac surgery with global myocardial ischemia-reperfusion (I/R) induces a myocardial inflammatory response that impairs cardiac recovery. Chemokines contribute to the overall myocardial inflammatory response through inducing leukocyte infiltration. Although Toll-like receptor 4 (TLR4) has an important role in postischemic myocardial injury, the relative roles of myocardial tissue and leukocyte TLR4 in leukocyte infiltration, as well as the role of TLR4 in myocardial chemokine expression, are unclear. Our recent study, in an isolated mouse heart model of global I/R, found that the 70-kDa heat shock cognate protein (HSC70) is released from cardiac cells and mediates the expression of cardiodepressant cytokines via a TLR4-dependent mechanism. In the present study, we tested the hypotheses that myocardial tissue TLR4 has a major role in mediating neutrophil infiltration and that myocardial TLR4 and extracellular HSC70 contribute to the mechanisms underlying cardiac chemokine response to global I/R. We subjected hearts isolated from TLR4-defective and TLR4-competent mice to global I/R and examined myocardial neutrophil infiltration and expression of keratinocyte-derived chemokine (KC) and monocyte chemoattractant protein-1 (MCP-1). TLR4-defective hearts exhibited reduced neutrophil infiltration regardless of the phenotypes of neutrophils perfused during reperfusion and expressed lower levels of KC and MCP-1. HSC70-specific antibody reduced myocardial expression of KC and MCP-1 after I/R. Furthermore, perfusion of HSC70 increased KC and MCP-1 expression in TLR4-competent hearts but not in TLR4-defective hearts, and HSC70 also induced the chemokine response in macrophages in a TLR4-dependent fashion. A recombinant HSC70 fragment lacking the substrate-binding domain was insufficient to induce chemokine expression in hearts and cells. This study demonstrates that myocardial tissue TLR4, rather than neutrophil TLR4, is the determinant of myocardial neutrophil infiltration after global I/R. TLR4 mediates myocardial chemokine expression, and the mechanisms involve extracellular HSC70. These results imply the HSC70-TLR4 interaction as a novel mechanism underlying the myocardial chemokine response to global I/R.