Minimizing Systemic Inflammation During Cardiopulmonary Bypass in the Pediatric Population

Promising results of a clinical feasibility study: CIRBP as a potential biomarker in pediatric cardiac surgery

Objective

Cold-inducible RNA binding Protein (CIRBP) has been shown to be a potent inflammatory mediator and could serve as a novel biomarker for inflammation. Systemic inflammatory response syndrome (SIRS) and capillary leak syndrome (CLS) are frequent complications after pediatric cardiac surgery increasing morbidity, therefore early diagnosis and therapy is crucial. As CIRBP serum levels have not been analyzed in a pediatric population, we conducted a clinical feasibility establishing a customized magnetic bead panel analyzing CIRBP in pediatric patients undergoing cardiac surgery.

Methods

A prospective hypothesis generating observational clinical study was conducted at the German Heart Center Berlin during a period of 9 months starting in May 2020 (DRKS00020885, https://drks.de/search/de/trial/DRKS00020885). Serum samples were obtained before the cardiac operation, upon arrival at the pediatric intensive care unit, 6 and 24 h after the operation in patients up to 18 years of age with congenital heart disease (CHD). Customized multiplex magnetic bead-based immunoassay panels were developed to analyze CIRBP, Interleukin-1β (IL-1β), Interleukin-6 (IL-6), Interleukin-8 (IL-8), Interleukin-10 (IL-10), Monocyte chemotactic protein 1 (MCP-1), Syndecan-1 (SDC-1), Thrombomodulin (TM), Vascular endothelial growth factor (VEGF-A), Angiopoietin-2 (Ang-2), and Fibroblast growth factor 23 (FGF-23) in 25 µl serum using the Luminex MagPix® system.

Results

19 patients representing a broad range of CHD (10 male patients, median age 2 years, 9 female patients, median age 3 years) were included in the feasibility study. CIRBP was detectable in the whole patient cohort. Relative to individual baseline values, CIRBP concentrations increased 6 h after operation and returned to baseline levels over time. IL-6, IL-8, IL-10, and MCP-1 concentrations were significantly increased after operation and except for MCP-1 concentrations stayed upregulated over time. SDC-1, TM, Ang-2, as well as FGF-23 concentrations were also significantly increased, whereas VEGF-A concentration was significantly decreased after surgery.

Discussion

Using customized magnetic bead panels, we were able to detect CIRBP in a minimal serum volume (25 µl) in all enrolled patients. To our knowledge this is the first clinical study to assess CIRBP serum concentrations in a pediatric population.

Risk Factors for Surgical Site Infection in Patients Undergoing Pediatric Cardiac Surgery

BACKGROUND

Central Illustration : Risk Factors for Surgical Site Infection in Patients Undergoing Pediatric Cardiac Surgery Risk factors for surgical site infection in patients undergoing pediatric cardiac surgery.

BACKGROUND

Surgical site infection is an important complication after pediatric cardiac surgery, associated with increased morbidity and mortality.

OBJECTIVES

We sought to identify risk factors for surgical site infection after pediatric cardiac surgeries.

METHODS

A case-control study included patients aged between 1 year and 19 years and 11 months of age, submitted to cardiac surgery performed at a tertiary cardiac center from January 1 st , 2011, through December 31, 2018. Charts were reviewed for pre-, intra, and postoperative variables. We identified two randomly selected control patients with the same pathophysiological diagnosis and underwent surgery within thirty days of each index case. Univariate and multivariate logistic regression analyses were performed to identify risk factors. Statistical significance was defined as p<0.05.

RESULTS

Sixty-six cases and 123 controls were included. Surgical site infection incidence ranged from 2% to 3.8%. The following risk factors were identified: Infant age (OR 3.19, 95% CI 1.26 to 8.66, p=0.014), presence of genetic syndrome (OR 6.20, CI 95% 1.70 to 21.65, p=0.004), categories 3 and 4 of RACHS-1 (OR 8.40, CI 95% 3.30 to 21.34, p<0.001), 48 h C-reactive protein level range was detected as a protective factor for this infection (OR 0.85, 95% CI 0.73 to 0.98, p=0.023).

CONCLUSIONS

The risk factors defined in this study could not be modified. Therefore, additional surveillance and new preventive strategies need to be implemented to reduce the incidence of surgical site infection. The increased CRP in the postoperative period was a protective factor that needs further understanding.

Coagulation after paediatric miniaturised versus conventional cardiopulmonary bypass: Retrospective cohort study

BACKGROUND

Cardiopulmonary bypass (CPB) causes coagulation disorders after surgery. This study aimed to compare the coagulation parameters after congenital cardiac surgery with miniaturised CPB (MCPB) versus conventional CPB (CCPB).

METHODS

We gathered information about children who underwent cardiac surgery between 1/1/2016 and 12/31/2019. Using propensity score-matched data, we compared the coagulation parameters and postoperative outcomes of the MCPB and CCPB groups.

RESULTS

A total of 496 patients (327 with MCPB, 169 withCCPB) underwent congenital cardiac surgery, and 160 matched pairs in each group were enrolled in the analysis. Compared with CCPB children, MCPB children had a lowermean prothrombin time (14.9 ± 2.0 vs 16.4 ± 4.1; p < 0.001)and international normalised ratio (1.3 ± 0.2 vs. 1.4 ± 0.3; p < 0.001), but higher thrombin time (23.4 ± 20.4 vs 18.2 ± 4.4; p = 0.002). The CCPB group had greaterperioperative changes inprothrombin time, international normalised ratio, fibrinogen, and antithrombin III activity (all p < 0.01) but lower perioperative changesin thrombin time (p = 0.001) thanthe MCPB group. Ultra-fasttrack extubation and blood transfusionrates, postoperative blood loss, and intensive care unitlength of stay were considerably decreased in the MCPB group. There were no considerable intergroup differences in the activated partial thromboplastin time or platelet count.

CONCLUSIONS

Compared with CCPB, MCPB was associated with lower coagulation changes and better early outcomes, including shorter intensive care unit stay and less postoperative blood loss.

The Anti-Inflammatory and Antioxidant Effects of Propofol and Sevoflurane in Children With Cyanotic Congenital Heart Disease

OBJECTIVE

The authors aimed to compare the anti-inflammatory and antioxidant effects of propofol and sevoflurane in children with cyanotic congenital heart disease (CCHD) undergoing cardiac surgery with cardiopulmonary bypass.

DESIGN

Prospective, randomized, double-blind study.

SETTING

Single center, university hospital.

PARTICIPANTS

Children ages 1-10 years with CCHD undergoing elective cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

Children were randomized to receive general anesthesia with either sevoflurane (group S) or propofol (group P). Systemic inflammatory response syndrome (SIRS) occurrence was assessed at the end of the surgery and at the sixth, 12th, and 24th postoperative hours. Blood samples were obtained at 4 times: after anesthesia induction (T0), after release of the aortic cross-clamp (T1), at the end of the surgery (T2), and at the postoperative 24th hour (T3). The serum levels of interleukin 6 and tumor necrosis factor alpha, and the total antioxidant status (TAS) and total oxidant status, were analyzed.

RESULTS

SIRS was more common in group S than in group P at all times (p = 0.020, p = 0.036, p = 0.004, p = 0.008). There were no significant differences between the groups in the mean tumor necrosis factor alpha and interleukin 6 levels at any time. The TAS level at T2 was higher in group P than group S (p = 0.036). The serum TAS level increased at T2 compared with T0 in group P, but it decreased in group S (p = 0.041).

CONCLUSION

The results showed that propofol provided a greater antioxidant effect and reduced SIRS postoperatively more than sevoflurane in children with CCHD undergoing cardiac surgery.

Elevated nuclear and mitochondrial cell-free deoxyribonucleic acid measurements are associated with death after infant cardiac surgery

OBJECTIVES

Mortality rates following pediatric cardiac surgery with cardiopulmonary bypass have declined over decades, but have plateaued in recent years. This is in part attributable to persistent issues with postoperative global inflammation and myocardial dysfunction, commonly manifested by systemic inflammatory response syndrome and low cardiac output syndrome, respectively. Quantified cell-free DNA (cfDNA), of nuclear or mitochondrial origin, has emerged as a biomarker for both inflammation and myocardial injury. Recent data suggest that nuclear cfDNA (ncfDNA) may quantify inflammation, whereas mitochondrial cfDNA (mcfDNA) may correlate with the degree of myocardial injury. We hypothesize that threshold levels of ncfDNA and mcfDNA can be established that are sensitive and specific for postoperative mortality mediated through independent pathways, and that association will be enhanced with combined analysis.

METHODS

Prospective observational study of infants younger than age 1 year undergoing planned surgery with cardiopulmonary bypass. The study received institutional review board approval. Samples were drawn before skin incision, immediately after completion of cardiopulmonary bypass, and subsequently at predetermined intervals postoperatively. Association of early postoperative ncfDNA and mcfDNA levels with mortality were assessed by logistic regression with cut-points chosen by receiving operating characteristic curve exploration.

RESULTS

Data were available in 59 patients. Median age and weight were 122 days (interquartile range, 63-154 days) and 4.9 kg (interquartile range, 3.9-6.2 kg). Median STAT category was 3 (interquartile range, 1-4). The primary outcome of death was met in 3 out of 59 (5%). Combined analysis of ncfDNA and mcfDNA levels at 12 hours after the initiation of cardiopulmonary bypass with death at a threshold of 50 ng/mL ncfDNA and 17 copies/μL mcfDNA yielded 100% sensitivity and negative predictive value. The specificity (91%) and positive predictive value (38%) increased through combined analysis compared with univariate analysis. Combined analysis exhibited high specificity (93%) and negative predictive value (78%) for prolonged (>30 postoperative days) hospitalization.

CONCLUSIONS

Combined analysis of early postoperative ncfDNA and mcfDNA can stratify risk of mortality and prolonged hospitalization following infant cardiac surgery. Evaluation of both ncfDNA and mcfDNA to identify states of generalized inflammation and myocardial injury may allow for targeted interventions and improved outcomes.

Analysis of inflammatory cytokines in the chest tube drainage of post-operative superior cavopulmonary connection patients

INTRODUCTION

Prolonged pleural effusions are common post Fontan operation and are associated with morbidity. Fontan pleural effusions have elevated proinflammatory cytokines. Little is known about the chest tube drainage after a superior cavopulmonary connection. We examined the chest tube drainage and the inflammatory profiles in post-operative superior cavopulmonary connection patients.

METHODS

This prospective cohort study enrolled 25 patients undergoing superior cavopulmonary connection and 10 age-similar controls. Data are also compared to 25 previously published Fontan patients and their 15 age-similar controls. Chest tube samples were analysed with a 17-cytokine BioPlex Assay. Descriptive statistics and univariate comparisons were made between groups.

RESULTS

Duration of chest tube drainage was significantly shorter in superior cavopulmonary connection patients (median 4 days, [interquartile range 3-5 days]) versus Fontan patients (10 days, [7-11 days], p < 0.0001). Cytokine concentrations were higher on post-operative day 1 in superior cavopulmonary connection patients versus Fontan patients (all p ≤ 0.01), however levels were comparable to age-similar controls. While proinflammatory IL 8, MIP-1β, and TNF-α concentrations increased in chest tube drainage of Fontan patients from post-operative day 1 to last chest tube day (all p < 0.0001), there was no change in these biomarkers in superior cavopulmonary connection patients, their controls, or Fontan controls.

CONCLUSIONS

Our study demonstrates that after superior cavopulmonary connection, proinflammatory cytokines in the chest tube drainage remain similar to biventricular controls of both age groups, unlike the significant rise over time observed in Fontan patients. Inflammation within the chest tube drainage is likely not innate to single ventricle patients.

Application of Adsorptive Blood Purification Techniques during Cardiopulmonary Bypass in Cardiac Surgery

By reason of surgical demand, the majority of cardiovascular procedures still depend on the use of cardiopulmonary bypass (CPB). Due to the nonphysiological state of CPB, it can cause complex and unpredictable inflammatory response, which may lead to significant morbidity and mortality. Unfortunately, the pharmacological and mechanical strategies that currently exist do not offer significant advantages in controlling inflammatory response and improving patient outcomes. The best strategy to reduce inflammation in CPB is still uncertain. In recent years, adsorptive blood purification techniques (BPTs) have emerged, among which CytoSorb is the latest representative device. Currently, the primary application area of adsorptive BPTs is in the control and treatment of systemic hyperinflammatory states, such as refractory septic shock patients. However, the evidences on efficacy and safety of adsorptive BPTs application during CPB surgery are still inconclusive, so we summarize the relevant evidences here and suggest future potential research areas.

Initial results from an enhanced recovery program for pediatric cardiac surgical patients

BACKGROUND

Over recent years, a number of enhanced recovery programs have appeared in first, adult colorectal surgery, and subsequently many other adult surgical specialties. Increasing interest in this approach to perioperative management in children culminated in the recent development of the first enhanced recovery pathway for pediatric intestinal surgery, endorsed by Enhanced Recovery after Surgery Society (ERAS®). In parallel, there has been increasing interest in the refinement of perioperative management of selected pediatric cardiac surgical patients, invariably referred to as "fast track" management. Initiatives have largely focused on duration of postoperative ventilation rather than on a much wider range of perioperative interventions to optimize recovery and ensure timely discharge after surgery. In our institution, a "Level 1" pediatric cardiac surgical center, we assembled a multidisciplinary team to design a comprehensive enhanced recovery pathway, based on ERAS® methodology, for selected cardiac surgical patients. After a lengthy period of planning, staff education, and preparation, we implemented the pathway at the end of November 2019.

METHODS

We conducted a prospective audit of the perioperative management and outcomes of the first 88 patients managed according to this enhanced recovery pathway over a 25-month period in our institution.

RESULTS

The mean age of the patients was 5.8 years (range 0.5-17.9), and the mean weight was 22.4 kg (range 6.6-57.2). Sixty-eight of the 88 patients were cardiopulmonary bypass cases. A total of 54% of patients received all four defined intraoperative anesthetic interventions (intravenous paracetamol, non-steroidal anti-inflammatory drug, antiemetic if aged more than 4 years, and use of a local anesthetic technique). A total of 89% of patients met the target extubation time of 6 h after administration of protamine. Median postoperative intensive care unit length of stay was 23.5 h (range 15.2-89.5). When compared to a historic control group, this represented a 22% reduction in median intensive care unit stay, although the total hospital length of stay remained unchanged. A total of 83% of patients met the target hospital discharge target of the fifth postoperative day.

CONCLUSIONS

These preliminary results suggest that enhanced recovery pathway implementation for selected pediatric cardiac surgical patients is feasible, with acceptable outcomes. They suggest areas for further development and the potential for wider implementation.

Postoperative Pulmonary Hemodynamics and Systemic Inflammatory Response in Pediatric Patients Undergoing Surgery for Congenital Heart Defects

There is scarce information about the relationships between postoperative pulmonary hemodynamics, inflammation, and outcomes in pediatric patients with congenital cardiac communications undergoing surgery. We prospectively studied 40 patients aged 11 (8–17) months (median with interquartile range) with a preoperative mean pulmonary arterial pressure of 48 (34–54) mmHg who were considered to be at risk for postoperative pulmonary hypertension. The immediate postoperative pulmonary/systemic mean arterial pressure ratio (PAP/SAP_IPO, mean of first 4 values obtained in the intensive care unit, readings at 2-hour intervals) was correlated directly with PAP/SAP registered in the surgical room just after cardiopulmonary bypass (r = 0.68, p < 0.001). For the entire cohort, circulating levels of 15 inflammatory markers changed after surgery. Compared with patients with PAP/SAP_IPO ≤ 0.40 (n = 22), those above this level (n = 18) had increased pre- and postoperative serum levels of granulocyte colony-stimulating factor (p = 0.040), interleukin-1 receptor antagonist (p = 0.020), interleukin-6 (p = 0.003), and interleukin-21 (p = 0.047) (panel for 36 human cytokines) and increased mean platelet volume (p = 0.018). Using logistic regression analysis, a PAP/SAP_IPO > 0.40 and a heightened immediate postoperative serum level of macrophage migration inhibitory factor (quartile analysis) were shown to be predictive of significant postoperative cardiopulmonary events (respective hazard ratios with 95% CIs, 5.07 (1.10–23.45), and 3.29 (1.38–7.88)). Thus, the early postoperative behavior of the pulmonary circulation and systemic inflammatory response are closely related and can be used to predict outcomes in this population.

Mean platelet volume-to-platelet count ratio after elective cardiac surgical procedures is superior in reflecting platelets metabolic hyperactivity compared to other routine morphological platelet indices: A preliminary report

BACKGROUND

Excessive metabolic excitation of platelets after cardiac procedures may be related to some adverse events but assessment of their metabolic activity is not routine. The purpose of this study was to evaluate which of the basic platelet morphological parameters best reflects their metabolic status.

METHODS

The blood samples of 22cardiac surgical patients (mean age of 62.3 ± 10.3 years) were taken before surgery (BS), and 1, 24 and 48 hours after the operation. Correlations between morphological platelet parameters (platelet count [PLT], mean platelet volume [MPV], platelet distribution width [PDW] and MPV/PLT) and their metabolic activity (total concentration of malondialdehyde [MDA] and MDA/PLT) were estimated.

RESULTS

Significant decline in PLT after operation (from 223 ± 44 × 10¹²/L to 166 ± 57 × 10¹²/L) was accompanied by marked increase in MPV (from 8.4 ± 0.9 fL to 9.1 ± 1.2 fL) and no change of PDW. Consequently, MPV/PLT index increased significantly after procedures from (median with IQR) 0.038 (0.030-0.043) to 0.053 (0.043-0.078). Simultaneously, a significant increase in total platelet MDA content and MDA/PLT was noted reaching peak levels soon after operation. The strongest correlation was observed between MPV/PLT and MDA/PLT (r = 0.56; p < 0.001), although the others were also found to be significant (MDA/PLT vs. MPV; r = 0.35; MDA/PLT vs. PDW; r = 0.34).

CONCLUSIONS

Among basic morphological parameters and indices, the MPV-to-PLT ratio reflects the best metabolic status of platelets in cardiac surgical patients.

Management of congenital cardiac surgery during COVID-19 pandemic

The new coronavirus infection, which was first seen in China in late December, 2019 and eventually became a worldwide pandemic, poses a serious threat to public health. After a high spike in the number of new COVID-19 infection cases following the increase in overall daily death toll in Turkey, Turkish Ministry of Health has taken immediate precautions to postpone elective surgeries in order to reduce the burden to the healthcare system which might be challenged. Whereas different areas of medicine were able to suspend their operative procedures during this period, this was not completely possible in paediatric cardiovascular surgery due to the severity and urgency of congenital heart disease patients requiring operation. Based on the guideline that was published by the Turkish Paediatric Cardiology and Cardiac Surgery Association, in which the patients requiring surgical intervention during the COVID-19 pandemic period are ranked according to the priority, directions were given regarding the operations that hereby, be delayed, we report our experience in 29 cases retrospectively, regarding the pre-operative evaluation of these patients, makings of an emergency operation decision, and strategies taken about intra-operative and post-operative management and arrangements during the pandemic period. In this article, we present crucial precautions that were applied in paediatric cardiovascular surgery and extensive list of cases in order to deliver highest level of the patient safety and protection for the surgical team.

Impact of miniaturized cardiopulmonary bypass circuits on ultrafiltration during congenital heart surgery

OBJECTIVE

To investigate whether the miniaturized cardiopulmonary bypass (CPB) system decreased the usage of ultrafiltration (UF), and to explore whether the non-UF with miniaturized CPB strategy could get good clinical results during congenital heart surgery.

METHODS

We performed a retrospective analysis of all patients undergoing congenital heart surgery with CPB at Shenzhen Children's Hospital from 1 May 2015 to 30 September 2019. We classified patients to UF with miniaturized CPB group, non-UF with miniaturized CPB group, UF with conventional CPB group and non-UF with conventional CPB group.

RESULTS

Of the 2145 patients, 721 (33.6%) were in the conventional CPB group, and 1424 (66.4%) were in the miniaturized CPB group. The UF rate was significantly lower in the miniaturized CPB group compared with that in the conventional CPB group (12.5% vs. 76.8%, p < 0.001). Compared with patients in the other groups, patients in the non-UF with miniaturized CPB group had a shorter postoperative MV time (p < 0.05), and a shorter length of stay in the ICU (p < 0.001) and hospital (p < 0.001). The age of children in the UF with miniaturized CPB group was relatively younger (median: 1.5 months, IQR: 0.3-4.6 months), and the preoperative weight was relatively lower (median: 3.9 kg, IQR: 3.2-5.4 kg). Moreover, this group of children had a relatively longer postoperative MV time and length of stay in the ICU and hospital.

CONCLUSION

The miniaturized CPB system could decrease the usage of UF. Good results were achieved in children who did not use UF based on the miniaturized CPB circuit system during congenital heart surgery.

Oxidative stress under general intravenous and inhalation anaesthesia

Oxidative stress occurs when reactive oxygen species (ROS) production overwhelms cell protection by antioxidants. This review is focused on general anaesthesia-induced oxidative stress because it increases the rate of complications and delays recovery after surgery. It is important to know what effects of anaesthetics to expect in terms of oxidative stress, particularly in surgical procedures with high ROS production, because their either additive or antagonistic effect may be pivotal for the outcome of surgery. In vitro and animal studies on this topic are numerous but show large variability. There are not many human studies and what we know has been learned from different surgical procedures measuring different endpoints in blood samples taken mostly before and after surgery. In these studies most intravenous anaesthetics have antioxidative properties, while volatile anaesthetics temporarily increase oxidative stress in longer surgical procedures.

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.

Comparison of Postoperative Changes in Inflammatory Marker Levels Between Transthoracic and Transcatheter Device Closures of Atrial Septal Defects in Children

Objective

To explore the postoperative changes in inflammatory markers in children who underwent device closure of an atrial septal defect (ASD) via a transthoracic or transcatheter approach.

Methods

The experimental and clinical data were retrospectively collected and analyzed for a total of 53 pediatric patients between September 2018 and December 2018. According to the different treatments, 19 patients who underwent transthoracic device closure were assigned to group A, and the remaining 34 patients who underwent a transcatheter approach were assigned to group B.

Results

All patients were successfully occluded without any device-related severe complication. Compared with the preoperative levels, the postoperative levels of most inflammatory cytokines in both groups were significantly increased and reached a peak on the first day after the procedure. The level of postoperative inflammatory cytokines was significantly lower in group B than in group A. In addition, there was no significant difference in procalcitonin before and after the transcatheter approach.

Conclusion

Systemic inflammatory reactions occurred after transthoracic or transcatheter device closure of ASDs in pediatric patients. However, these inflammatory reactions were more significant in patients who underwent a transthoracic approach than in patients who underwent a transcatheter approach.

Perioperative care of the newborns with CHDs in the time of COVID-19

Coronavirus disease 2019 (COVID-19), caused by a novel betacoronavirus (SARS-CoV-2), has led to an unexpected outbreak affecting people of all ages. The first data showed that COVID-19 could cause severe pulmonary disease, cardiac injury, and death in adults, especially the elderly and those with concomitant diseases. Currently, it was demonstrated that severe COVID-19 may also develop in neonatal age, although rarely. Newborns with CHD are known to be at high risk for increased morbidity from viral lower respiratory tract infections because of underlying anatomical cardiac lesions. There are limited data on the implications of COVID-19 on patients with cardiovascular disease, especially for those with CHD. Herein, we aimed to summarise the COVID-19-specific perioperative management issues for newborns with CHD by combining available data from the perspectives of neonatology and paediatric cardiovascular surgery.

Deficiency of Interleukin-36 Receptor Protected Cardiomyocytes from Ischemia-Reperfusion Injury in Cardiopulmonary Bypass

Background

Interleukin-36 has been demonstrated to be involved in inflammatory responses. Inflammatory responses due to ischemia-reperfusion injury following cardiopulmonary bypass (CPB) can cause heart dysfunction or damage.

Material/Methods

The CPB models were constructed in IL-36R−/−, IL-36RN−/−, and wild-type SD rats. Ultrasonic cardiography and ELISA were used to evaluate the cardiac function and measuring myocardial biomarker levels in different groups. TUNEL assay was used to evaluate apoptosis. Western blot assays and RT-PCR were performed to measure the expression of chemokines and secondary inflammatory cytokines in the heart. Oxidative stress in tissue and cultured cells was assessed using a DCFH-DA fluorescence probe and quantification of superoxide dismutase activity.

Results

Improved systolic function and decreased serum levels of myocardial damage biomarkers were found in IL-36R−/− rats compared to WT rats, while worse cardiac function and cardiomyocyte IR injury were observed in IL-36RN−/− rats compared to WT rats. TUNEL staining and Western blot analyses found that cardiomyocyte apoptosis and inflammation were significantly lower in the hearts of IL-36R−/− rats compared with that of WT rats. Oxidative stress was significantly lower in IL-36R−/− rats compared to WT rats. iNOS expression was significantly reduced, while eNOS expression was increased in the hearts of IL-36R−/− rats. Silencing of IL-36R expression in vitro activated SIRT1/FOXO1/p53 signaling in cardiomyocytes.

Conclusions

IL-36R deficiency in cardiomyocytes repressed infiltration of bone marrow-derived inflammatory cells and oxidative stress dependent on SIRT1-FOXO1 signaling, thus protecting cardiomyocytes and improving cardiac function in CPB model rats.

Effect of retrograde autologous priming based on miniaturized cardiopulmonary bypass in children undergoing open heart surgery: A STROBE compliant retrospective observational study

To evaluate the effectiveness of retrograde autologous priming (RAP) based on miniaturized cardiopulmonary bypass (CPB) circuit in children undergoing open heart surgery.We performed a retrospective analysis of all patients (≤15 kg) who underwent open heart surgery with CPB in our center from January 1, 2017, to July 31, 2019. Propensity score matching was used to adjust for significant covariates, and multivariable stratified analysis was used to assess the association of the RAP technique with clinical outcomes.A total of 1111 patients were analyzed. There were 355 (32.0%) children who underwent RAP, and 756 (68.0%) were in the non-RAP group. After propensity score matching, there were a total of 638 patients, with 319 patients in each group. The bloodless priming rate was significantly higher (P = .013), and the ultrafiltration rate was significantly lower (P = .003) in the RAP group than in the non-RAP group. Compared with patients in the non-RAP group, patients in the RAP group had a shorter postoperative mechanical ventilation time (P < .001) and shorter lengths of stay in the intensive care unit (ICU) (P < .001) and the hospital (P < .001). No differences were noted in postoperative hematocrit (P = .920), postoperative 24-hour blood loss (P = .435), and hospital mortality (P = .563). In the stratified analysis, the difference remained statistically significant (P < .05) when the patient weight was >4 kg or the Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery (STAT) category was <3. However, when the patient weight was ≤4 kg or the STAT category was ≥3, there was no significant difference between the 2 groups in terms of bloodless priming, ultrafiltration, postoperative mechanical ventilation time, or length of stay in the ICU or the hospital (P > .05).The RAP technique based on miniaturized CPB system was safe and effective for children who underwent congenital heart surgery. The RAP technique can significantly reduce the priming volume, improve the rate of bloodless priming, and reduce blood product application. It was also associated with a shorter postoperative mechanical ventilation time and shorter lengths of stay in the ICU and the hospital.

Extracorporeal life support and systemic inflammation

Extracorporeal life support (ECLS) encompasses a wide range of extracorporeal modalities that offer short- and intermediate-term mechanical support to the failing heart or lung. Apart from the daily use of cardiopulmonary bypass (CPB) in the operating room, there has been a resurgence of interest and utilization of veno-arterial and veno-venous extracorporeal membrane oxygenation (VA- and VV-ECMO, respectively) and extracorporeal carbon dioxide removal (ECCO₂R) in recent years. This might be attributed to the advancement in technology, nonetheless the morbidity and mortality associated with the clinical application of this technology is still significant. The initiation of ECLS triggers a systemic inflammatory response, which involves the activation of the coagulation cascade, complement systems, endothelial cells, leukocytes, and platelets, thus potentially contributing to morbidity and mortality. This is due to the release of cytokines and other biomarkers of inflammation, which have been associated with multiorgan dysfunction. On the other hand, ECLS can be utilized as a therapy to halt the inflammatory response associated with critical illness and ICU therapeutic intervention, such as facilitating ultra-protective mechanical ventilation. In addition to addressing the impact on outcome of the relationship between inflammation and ECLS, two different but complementary pathophysiological perspectives will be developed in this review: ECLS as the cause of inflammation and ECLS as the treatment of inflammation. This framework may be useful in guiding the development of novel therapeutic strategies to improve the outcome of critical illness.

Anti-oxidative or anti-inflammatory additives reduce ischemia/reperfusions injury in an animal model of cardiopulmonary bypass

Severe inborn cardiac malformations are typically corrected in cardioplegia, with a cardio-pulmonary bypass (CPB) taking over body circulation. During the operation the arrested hearts are subjected to a global ischemia/reperfusion injury. Although the applied cardioplegic solutions have a certain protective effect, application of additional substances to reduce cardiac damage are of interest.

18 domestic piglets (10–15 kg) were subjected to a 90 min CPB and a 120 min reperfusion phase without or with the application of epigallocatechin-3-gallate (10 mg/kg body weight) or minocycline (4 mg/kg body weight), with both drugs given before and after CPB. 18 additional sham-operated piglets without or with epigallocatechin-3-gallate or minocycline served as controls. In total 36 piglets were analyzed (3 CPB-groups and 3 control groups without or with epigallocatechin-3-gallate or minocycline respectively; 6 piglets per group). Hemodynamic and blood parameters and ATP-measurements were assessed. Moreover, a histological evaluation of the heart muscle was performed.

Results

Piglets of the CPB-group needed more catecholamine support to achieve sufficient blood pressure. Ejection fraction and cardiac output were not different between the 6 groups. However, cardiac ATP-levels and blood lactate were significantly lower and creatine kinase was significantly higher in the three CPB-groups. Markers of apoptosis, hypoxia, nitrosative and oxidative stress were significantly elevated in hearts of the CPB-group. Nevertheless, addition of epigallocatechin-3-gallate or minocycline significantly reduced markers of myocardial damage. Noteworthy, EGCG was more effective in reducing markers of hypoxia, whereas minocycline more efficiently decreased inflammation.

Conclusions

While epigallocatechin-3-gallate or minocycline did not improve cardiac hemodynamics, markers of myocardial damage were significantly lower in the CPB-groups with epigallocatechin-3-gallate or minocycline supplementation.

Analysis of Inflammatory Cytokines in Postoperative Fontan Pleural Drainage

Prolonged pleural drainage is a common complication in patients after Fontan palliation and is associated with short- and long- term morbidities. Among many potential etiologies, prolonged drainage has an inflammatory component, but there are no descriptions of cytokines in Fontan pleural drainage to date. This study aimed to examine the inflammatory make-up of Fontan pleural drainage. This prospective age-range-matched cohort study recruited 25 patients undergoing Fontan procedure and 15 bi-ventricular patients undergoing cardiopulmonary bypass (CPB). Chest tube samples were taken on postoperative day (POD) 1-4, 7, and 10. Cytokines were measured using Bio-Plex Assays. Univariate comparisons were made in patient characteristics and cytokine levels. Median age was 3.7 y (IQR 2.8-3.9) for controls and 2.5 y (IQR 2.1-2.9) in Fontan patients (p = 0.02). Median drainage duration and daily volume was higher in Fontan patients (both p < 0.001). Inflammatory cytokines (IL-17A, IFN-y, MIP-1β, and TNF-α) were higher in Fontan patients than controls (all p < 0.02). There was an increase in pro-inflammatory cytokines (IL-8, MIP-1β, and TNF-α) from POD1 to the last chest tube day (LCD) in Fontan patients (all p < 0.0001) and a decrease in the anti-inflammatory cytokine IL-10 (p = 0.001). There was no difference in cytokine concentration from POD1 to LCD among controls. There was a significant association with the cytokine concentration of TNF-α on POD1 and duration of chest tube drainage (p < 0.05). Inflammatory cytokine levels in the pleural fluid of Fontan patients are higher compared to bi-ventricular controls and rise over time where controls do not. This suggests ongoing localized inflammation that is not a result of CPB alone and may be an important contributor to pleural drainage in patients after the Fontan procedure.

Comparison of two cardiopulmonary bypass strategies with a miniaturized tubing system: a propensity score-based analysis

INTRODUCTION

The existing cardiopulmonary bypass tubing system has already been significantly improved in our hospital by reducing the priming volume; thus, we further employed a new cardiopulmonary bypass strategy in children based on a miniaturized cardiopulmonary bypass circuit. We aimed to compare the effectiveness of new and conventional strategies by analyzing the outcomes after congenital heart surgery.

METHODS

We performed a database analysis of all patients undergoing congenital heart surgery with cardiopulmonary bypass at Shenzhen Children's Hospital from 1 May 2015 to 30 June 2017. Propensity score matching was used to adjust for significant covariates, and multivariable regression models and stratified analysis were used to assess the association of cardiopulmonary bypass strategy with outcomes.

RESULTS

Of 925 total patients, 55.35% were in the conventional strategy group and 44.65% were in the new strategy group. After propensity score matching, there were 610 patients in total, with 305 patients in each group. In the multivariable regression models, the cardiopulmonary bypass strategy was not significantly associated with successful early extubation (p > 0.05), reintubation (p > 0.05), or nasal continuous positive airway pressure (p > 0.05) rates. The new strategy group had fewer hospital stays (p = 0.04) and intensive care unit stays (p < 0.05) compared with patients who underwent conventional strategy. The difference remained statistically significant (p < 0.05) when The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery category was <3.

CONCLUSION

The implementation of a new cardiopulmonary bypass strategy, with selective ultrafiltration based on a miniaturized cardiopulmonary bypass circuit system, was safe and effective for children who underwent congenital heart surgery in a Chinese hospital. The new cardiopulmonary bypass strategy was associated with fewer hospital and intensive care unit stays.

Intravenous morphine versus intravenous paracetamol after cardiac surgery in neonates and infants: a study protocol for a randomized controlled trial

BACKGROUND

Morphine is worldwide the analgesic of first choice after cardiac surgery in children. Morphine has unwanted hemodynamic and respiratory side effects. Therefore, post-cardiac surgery patients may potentially benefit from a non-opioid drug for pain relief. A previous study has shown that intravenous (IV) paracetamol is effective and opioid-sparing in children after major non-cardiac surgery. The aim of the study is to test the hypothesis that intermittent IV paracetamol administration in children after cardiac surgery will result in a reduction of at least 30% of the cumulative morphine requirement.

METHODS

This is a prospective, multi-center, randomized controlled trial at four level-3 pediatric intensive care units (ICUs) in the Netherlands and Belgium. Children who are 0-36 months old will be randomly assigned to receive either intermittent IV paracetamol or continuous IV morphine up to 48 h post-operatively. Morphine will be available as rescue medication for both groups. Validated pain and sedation assessment tools will be used to monitor patients. The sample size (n = 208, 104 per arm) was calculated in order to detect a 30% reduction in morphine dose; two-sided significance level was 5% and power was 95%.

DISCUSSION

This study will focus on the reduction, or replacement, of morphine by IV paracetamol in children (0-36 months old) after cardiac surgery. The results of this study will form the basis of a new pain management algorithm and will be implemented at the participating ICUs, resulting in an evidence-based guideline on post-operative pain after cardiac surgery in infants who are 0-36 months old.

TRIAL REGISTRATION

Dutch Trial Registry ( www.trialregister.nl ): NTR5448 on September 1, 2015. Institutional review board approval (MEC2015-646), current protocol version: July 3, 2017.

Preoperative asymptomatic leukocytosis and postoperative outcome in cardiac surgery patients

BACKGROUND

Despite showing a prognostic value in general surgical patients, preoperative asymptomatic elevated white blood cell (WBC) count is not considered a risk factor for cardiac surgery. Whereas there is sporadic evidence of its value as a preoperative risk marker, it has not been looked at methodically as a specific index of outcome during cardiac surgery. Using a national database we sought to determine the relationship between preoperative WBC count and postoperative outcome in cardiac surgical patients.

METHODS

Cardiac surgeries were extracted from the 2007-2013 American College of Surgeons National Surgical Quality Improvement Program database. Leukocytosis was defined by a preoperative WBC count greater than 11,000 cells/μL. A univariate analysis compared the incidence of adverse outcomes for patients with and without leukocytosis. A multivariate logistic regression model was constructed in order to test whether leukocytosis was an independent predictor of morbidity and mortality.

RESULTS

Out of a total of 10,979 cardiac surgery patients 863 (7.8%) had preoperative leukocytosis. On univariate analysis, patients with leukocytosis experienced greater incidences of 30-day mortality, wound complications, and medical complications. Wound complications included surgical site infection as well as wound dehiscence. The medical complications included all other non-surgical causes of increased morbidity and infection leading to urinary tract infection, pneumonia, ventilator dependence, sepsis and septic shock. After stepwise model adjustment, leukocytosis was a strong predictor of medical complications (OR 1.22, 95% CI: 1.09-1.36, p = 0.002) with c-statistic of 0.667. However, after stepwise model adjustment leukocytosis was not a significant predictor of 30-day mortality and wound complications.

CONCLUSION

Preoperative leukocytosis is associated with adverse postoperative outcome after cardiac surgery and is an independent predictor of infection-related postoperative complications.

Promotion of anoxia-reoxygenation-induced inflammation and permeability enhancement by nicotinamide phosphoribosyltransferase-activated MAPK signaling in human umbilical vein endothelial cells

Previous studies have demonstrated that nicotinamide phosphoribosyltransferase (NAMPT) promoted inflammation and permeability of vascular endothelial cells following cardiopulmonary bypass (CPB). In addition, mitogen-activated protein kinase (MAPK) signaling was activated and contributed to these cell responses. However, the mechanism by which NAMPT regulates cellular inflammation and permeability remains unknown, and whether NAMPT regulates MAPK signaling during this process is also not clear. The present study established an anoxia-reoxygenation (A-R) model using human umbilical vein endothelial cells (HUVECs) and investigated the regulation of MAPK signaling by NAMPT by using small RNA transfection, ELISA and western blot analysis. The results demonstrated that A-R significantly induced the expression levels of NAMPT and cellular permeability-associated proteins, and the release of several inflammatory factors. Furthermore, calcium and MAPK signaling were evidently increased. When the A-R cells were transfected with NAMPT small interfering RNA, the expression of cellular permeability-associated proteins was downregulated, the release of inflammatory factors was decreased, and calcium and MAPK signaling was blocked. These data suggest that NAMPT may activate MAPK signaling to promote A-R-induced inflammation and permeability enhancement of HUVECs. Therefore, the current study indicates that NAMPT may be a potential drug target for A-R-induced endothelial cell injury subsequent to CPB.

Lung ultrasound profile after cardiopulmonary bypass in paediatric cardiac surgery: first experience in a simple cohort

Objectives

To explore the association between lung ultrasound (LUS) and clinical variables in children undergoing cardiopulmonary bypass (CPB).

Methods

A retrospective analysis was conducted in patients weighing <20 kg and with an Aristotle score <9, scanned with LUS on postoperative day (POD) 0, 1 and 2. We defined three LUS profiles: profile A: the prevalence of confluent B lines ("white lung"); profile B: the prevalence of B lines and profile C: the prevalence of A lines (normal lung).

Results

Median (interquartile range [IRQ]) weight, age and Aristotle score were 5.6 kg [IQR 4.0-6.0], 3.2 months [IQR 3.0-7.0] and 6.75 [IQR 6.0-8.0], respectively. No profile A patients were found. At POD1, we identified statistically significant differences between profile B and C patients: CPB time was 157 [IQR138-235] vs 95 [IQR 85-183] minutes ( P  <   0.005); aortic clamp duration was 104 [IQR 87-142] vs 54 [IQR 49-72] minutes ( P  =   0.007); time of mechanical ventilation was 41.5 [IQR 31.0-56.0] vs 15 [IQR 15-24] hours ( P  <   0.001); and ICU length of stay was 2 [IQR 2-3] vs 4 [IQR 3-4] days ( P  =   0.001), respectively. No differences were found between profile B and C patients at all the other time points. No statistically significant differences were found for blood gas values, urine output and fluid balance at all time points.

Conclusions

In a small cohort of children undergoing CPB, the LUS profile on POD1 was associated with CPB time, aortic cross-clamp time and mechanical ventilation duration.

Endothelial Cell Function and Dysfunction in Critically Ill Children

Endothelial cells (ECs) line the lumen of the entire vascular system and actively regulate blood flow; maintain blood fluidity; control water, solute, and macromolecular transfer between blood and tissue; and modulate circulating immune cell recruitment and activation. These vital functions, combined with the broad anatomic distribution of ECs, implicate them in all forms of critical illness. The present article discusses how ECs adapt and break down during the course of critical illness. We first review the biology of ECs, highlighting the vascular segmental differences and their specific roles in the maintenance of homeostasis. We then discuss how ECs acquire new functions to restore local and systemic homeostasis (activation) as well as how breakdowns in EC functions (dysfunction) contribute to local and systemic pathologic responses, with clinical correlations. Lastly, how these processes have been studied in critically ill children is discussed.

Timing of Haemophilus influenzae type b vaccination after cardiac surgery

BACKGROUND

The best time for vaccination in infants with congenital heart disease (CHD) after cardiopulmonary bypass (CPB) surgery is unclear, but it is important to prevent Haemophilus influenzae type b (Hib) infection in infants with CHD after CPB surgery. To identify the best time for Hib vaccination in infants with CHD after CPB surgery, we investigated the immunological status, and the efficacy and safety of Hib vaccination after CPB surgery.

METHODS

Sixteen subjects who underwent surgical correction of ventricular septal defect with CPB were investigated. Immunological status and cytokines were analyzed before surgery, 2 months after surgery, and before Hib booster vaccination. Hib-specific IgG was also measured to evaluate the effectiveness of vaccination.

RESULTS

Immunological status before and 2 months after surgery (e.g. whole blood cells and lymphocyte subset profile) was within the normal range and no subjects had hypercytokinemia. Additionally, all subjects who received Hib vaccination at 2-3 months after CPB surgery had effective serum Hib-specific IgG level for protection against Hib infection without any side-effects.

CONCLUSIONS

CPB surgery does not influence acquired immunity and Hib vaccination may be immunologically safe to perform at 2 months after CPB surgery. Hib vaccination at 2-3 months after CPB surgery was effective in achieving immunization for infants with simple left-right shunt-type CHD.

Activation of the lectin pathway of complement by cardiopulmonary bypass contributes to the development of systemic inflammatory response syndrome after paediatric cardiac surgery

The systemic inflammatory response is a challenge in the management of paediatric patients undergoing cardiac surgery. Although multi-factorial, a contribution by the lectin pathway of complement activation has been postulated. We therefore investigated the changes in serum levels of mannose binding lectin (MBL) and activities of MBL-MBL-associated serine protease (MASP)-1 and MBL-MASP-2 complexes immediately before and during surgery, throughout the first postoperative day and at discharge from the hospital. These changes were analysed in relation to postoperative complications. Blood samples were obtained from 185 children with congenital heart disease undergoing surgical correction with the use of cardiopulmonary bypass: preoperatively (MBL-1), 15 min after initiation of cardiopulmonary bypass (CPB) (MBL-E), 30 min (MBL-2), 4 h (MBL-3), 12 h (MBL-4) and 24 h (MBL-5) post-CPB and at discharge from hospital (MBL-K). Alterations in serum MBL levels were calculated as a ratio of its serum level at subsequent time-points (MBL-2, -3, -4, -5) to the preoperative (MBL-1) value. Decreases in MBL and MBL-MASP complexes were observed in all samples, correlating with a decrease in C4 and increase in C4a, confirming activation of the lectin pathway. Changes in MBL levels between children with an uncomplicated postoperative course and those suffering from infection or low cardiac output syndrome did not differ significantly, but significant differences were observed between the SIRS and non-SIRS groups. Paediatric cardiac surgery with the use of cardiopulmonary bypass activates the complement system via the lectin pathway and the latter contributes to the development of the post-bypass systemic inflammatory response.

Effects of propofol and isoflurane on haemodynamics and the inflammatory response in cardiopulmonary bypass surgery

Cardiopulmonary bypass (CPB) causes reperfusion injury that when most severe is clinically manifested as a systemic inflammatory response syndrome. The anaesthetic propofol may have anti-inflammatory properties that may reduce such a response. We hypothesised differing effects of propofol and isoflurane on inflammatory markers in patients having CBR Forty patients undergoing elective CPB were randomised to receive either propofol or isoflurane for maintenance of anaesthesia. CRP, IL-6, IL-8, HIF-1α (ELISA), CD11 and CD18 expression (flow cytometry), and haemoxygenase (HO-1) promoter polymorphisms (PCR/electrophoresis) were measured before anaesthetic induction, 4 hours post-CPB, and 24 hours later. There were no differences in the 4 hours changes in CRP, IL-6, IL-8 or CD18 between the two groups, but those in the propofol group had higher HIF-1α (P = 0.016) and lower CD11 expression (P = 0.026). After 24 hours, compared to the isoflurane group, the propofol group had significantly lower levels of CRP (P < 0.001), IL-6 (P < 0.001) and IL-8 (P < 0.001), with higher levels CD11 (P = 0.009) and CD18 (P = 0.002) expression. After 24 hours, patients on propofol had increased expression of shorter HO-1 GT(n) repeats than patients on isoflurane (P = 0.001). Use of propofol in CPB is associated with a less adverse inflammatory profile than is isofluorane, and an increased up-regulation of HO-1. This supports the hypothesis that propofol has anti-inflammatory activity.

A prospective randomized trial comparing the clinical effectiveness and biocompatibility of heparin-coated circuits and PMEA-coated circuits in pediatric cardiopulmonary bypass

OBJECT

We compared the clinical effectiveness and biocompatibility of poly-2-methoxyethyl acrylate (PMEA)-coated and heparin-coated cardiopulmonary bypass (CPB) circuits in a prospective pediatric trial.

METHODS

Infants randomly received heparin-coated (n=7) or PMEA-coated (n=7) circuits in elective pediatric cardiac surgery with CPB for ventricular septum defects. Clinical and hematologic variables, respiratory indices and hemodynamic changes were analyzed perioperatively.

RESULTS

Demographic and clinical variables were similar in both groups. Leukocyte counts were significantly lower 5 minutes after CPB in the PMEA group than the heparin group. Hemodynamic data showed that PMEA caused hypotension within 5 minutes of CPB. The respiratory index was significantly higher immediately after CPB and 1 hour after transfer to the intensive care unit (ICU) in the PMEA group, as were levels of C-reactive protein 24 hours after transfer to the ICU.

CONCLUSION

Our study shows that PMEA-coated circuits, unlike heparin-coated circuits, cause transient leukopenia during pediatric CPB and, perhaps, systemic inflammatory respiratory syndrome after pediatric CPB.