Risk stratification in neonates and infants submitted to cardiac surgery with cardiopulmonary bypass: a multimarker approach combining inflammatory mediators, N-terminal pro-B-type natriuretic peptide and troponin I

High-sensitive troponinT, interleukin-8, and interleukin-6 link with post-surgery risk in infant heart surgery

BACKGROUND

This study focuses on biomarkers in infants after open heart surgery, and examines the association of high-sensitive troponin T (hs-cTnT), interleukin-6 (IL-6), and interleukin-8 (IL-8) with postoperative acute kidney injury (AKI), ventilatory support time and need of vasoactive drugs.

METHODS

Secondary exploratory study from a double-blinded clinical randomized trial (Mile-1) on 70 infants undergoing open heart surgery with cardiopulmonary bypass (CPB). In this sub-study, the entire study population was examined without considering the study drugs. The biomarkers' peak concentration (highest concentration at 2 or 6 h post-CPB) were used for statistical analyses.

RESULTS

Peak IL-8, hs-cTnT, and IL-6 occurred at 2 h post-CPB for 96%, 79%, and 63% of the patients, respectively. The odds ratio of developing AKI2-3 for IL-6 > 293 pg/mL was 23.4 (95% CI 5.3;104.0), for IL-8 > 100 pg/mL it was 11.5 (3.0;44.2), and for hs-cTnT >5597 pg/mL it was 6.1 (1.5; 24.5). In more than two third of the patients with the highest peak concentrations of IL-8, IL-6, and hs-cTnT, there was a need for ventilatory support for >24 h and use of vasoactive drugs at 24 h post-CPB, while in less than one third of the patients with the lowest peak concentrations of IL-8 and hs-cTnT such requirements were observed.

CONCLUSIONS

The peak biomarker concentrations and CPB-time strongly predicted AKI2-3, with IL-6 and IL-8 emerging as strongest predictors. Furthermore, our findings suggest that measuring hs-cTnT and IL-8 just 2 h post-CPB-weaning may assist in identifying infants suitable for early extubation and highlight those at risk of prolonged ventilation.

Predictive value of NT-proBNP and hs-TnT for outcomes after pediatric congenital cardiac surgery

BACKGROUND

The available evidence regarding the predictive value of troponins and natriuretic peptides for early postoperative outcomes in pediatrics is limited, controversial, and based on small sample sizes. The authors aimed to investigate the association of N-terminal pro B-type natriuretic peptide (NT-proBNP) and high-sensitivity troponin T (hs-TnT) with the in-hospital adverse outcomes after congenital cardiac surgeries.

METHODS

A secondary analysis based on a prospective study of pediatric congenital heart disease (CHD) patients was conducted to investigate the association of NT-proBNP and hs-TnT tested within 6 h postoperatively with in-hospital adverse events. A multivariate logistic regression analysis with a minimum P value approach was used to identify the optimal thresholds of NT-proBNP and hs-TnT for risk stratification.

RESULTS

NT-proBNP and hs-TnT are positively correlated with cardiopulmonary bypass time, mechanical ventilation duration, and pediatric intensive care unit stay. The predictive performance of NT-proBNP is excellent for adverse events in both patients younger than 1 year [area under the curve (AUC): 0.771, 0.693-0.850] and those older than 1 year (AUC: 0.839, 0.757-0.922). However, hs-TnT exhibited a satisfactory predictive value solely in patients aged over 1 year. (AUC: 0.784, 0.717-0.852). NT-proBNP levels of 2000-10 000 ng/l [odds ratio (OR): 3.79, 1.47-9.76] and exceeding 10 000 ng/l (OR: 12.21, 3.66-40.80) were associated with a higher risk of postoperative adverse events in patients younger than 1 year. Patients older than 1 year, with NT-proBNP higher than 500 ng/l (OR: 15.09, 6.05-37.66) or hs-TnT higher than 1200 ng/l (OR: 5.50, 1.47-20.59), had a higher incidence of postoperative adverse events.

CONCLUSIONS

NT-proBNP and hs-TnT tested within postoperative 6 h demonstrated significant predictive value for postoperative adverse events in CHD patients older than 1 year. However, among CHD patients younger than 1 year, only NT-proBNP exhibited commendable predictive performance for postoperative adverse events.

Postoperative Troponin Levels in Children Undergoing Open Heart Surgery With and Without Coronary Intervention

We aimed to characterize the ranges, temporal trends, influencing factors, and prognostic significance of postoperative troponin levels after congenital heart surgery. This single-center retrospective study included patients from 2006 to 2021 who had ≥ 1 postoperative troponin-T measurement collected within 96 h of congenital heart surgery (CHS). Patients were grouped as Anomalous Aortic Origin of the Coronary Artery-"AAOCA repair," or congenital heart surgery with "Other Coronary Interventions" other than AAOCA repair, or "No Coronary Intervention." In each group, information on concomitant surgery requiring one or more of the following-atriotomy, ventriculotomy, right ventricular muscle bundle resection, and/or septal myectomy-was collected. Clinical correlates of troponin values were analyzed in three postoperative windows: < 8, 8-24, and 24-48 h. The highest median [range] troponin levels (ng/mL) for the samples were 0.34 [0.06, 1.32] at < 8 h for "AAOCA repair," 1.35 [0.14, 12.0] at < 8 h for those undergoing CHS with "Other Coronary Interventions," and 0.87 [0.06, 25.1] at 8-24 h for those undergoing CHS with "No Coronary Interventions." Atriotomy was associated with higher median troponin levels in the AAOCA group at < 8 h (0.40 [0.31, 0.77] vs. 0.29 [0.17, 0.54], P = 0.043) and in the Other Coronary Intervention group at 8-24 h (1.67 [1.04, 2.63] vs. 0.40 [0.19, 1.32], P = 0.002). Patients experiencing major postoperative complications (vs. those who did not) had higher troponin levels in the AAOCA group as early as 8-24 h (0.36 [0.24, 0.57] vs. 0.21 [0.14, 0.33], P = 0.03). Similar findings were noted in the Coronary Intervention (2.20 [1.34, 3.90] vs. 1.11 [0.51, 2.90], P = 0.028) and No Coronary Intervention (2.2 [1.49, 15.1] vs. 0.74 [0.40, 2.34], P = 0.027) groups but earlier at < 8 h. In the AAOCA group, 2/18 (11%) troponin outliers experienced cardiac arrest in comparison to 0/80 (0%) non-outliers (P = 0.032). In the Other Coronary Intervention group, troponin outliers had longer median times to ICU discharge (10 vs. 4 days) and hospital discharge (21 vs. 10 days) (both P < 0.001). Postoperative troponin levels depend on a multitude of factors and may have prognostic value in patients undergoing congenital heart surgery with coronary interventions.

Biomarker-based risk model to predict persistent multiple organ dysfunctions after congenital heart surgery: a prospective observational cohort study

BACKGROUND

Multiple organ dysfunction syndrome (MODS) is an important cause of post-operative morbidity and mortality for children undergoing cardiac surgery requiring cardiopulmonary bypass (CPB). Dysregulated inflammation is widely regarded as a key contributor to bypass-related MODS pathobiology, with considerable overlap of pathways associated with septic shock. The pediatric sepsis biomarker risk model (PERSEVERE) is comprised of seven protein biomarkers of inflammation and reliably predicts baseline risk of mortality and organ dysfunction among critically ill children with septic shock. We aimed to determine if PERSEVERE biomarkers and clinical data could be combined to derive a new model to assess the risk of persistent CPB-related MODS in the early post-operative period.

METHODS

This study included 306 patients < 18 years old admitted to a pediatric cardiac ICU after surgery requiring cardiopulmonary bypass (CPB) for congenital heart disease. Persistent MODS, defined as dysfunction of two or more organ systems on postoperative day 5, was the primary outcome. PERSEVERE biomarkers were collected 4 and 12 h after CPB. Classification and regression tree methodology were used to derive a model to assess the risk of persistent MODS.

RESULTS

The optimal model containing interleukin-8 (IL-8), chemokine ligand 3 (CCL3), and age as predictor variables had an area under the receiver operating characteristic curve (AUROC) of 0.86 (0.81-0.91) for differentiating those with or without persistent MODS and a negative predictive value of 99% (95-100). Ten-fold cross-validation of the model yielded a corrected AUROC of 0.75 (0.68-0.84).

CONCLUSIONS

We present a novel risk prediction model to assess the risk for development of multiple organ dysfunction after pediatric cardiac surgery requiring CPB. Pending prospective validation, our model may facilitate identification of a high-risk cohort to direct interventions and studies aimed at improving outcomes via mitigation of post-operative organ dysfunction.

The Trend of Urinary N Terminal Probrain Natriuretic Peptide in Extremely Low Birth Weight Infants during the Neonatal Period

OBJECTIVE

N-terminal probrain natriuretic peptide (NT-proBNP) is a biomarker of interest in many cardiopulmonary diseases in extremely low birth weight (ELBW) Infants. However, there is a gap in knowledge about the trend of ELBW infant's urinary NT-proBNP during the neonatal period.

AIM

To determine the trend of urinary NT-proBNP during the first 4 weeks of life of an ELBW infant.

STUDY DESIGN

We analyzed prospectively enrolled 87 ELBW infants. Urinary NT-proBNP to creatinine ratios were measured on days 1 to 7, 14, and 28 of life. We plotted each study point's means to determine the trend of urinary NT-proBNP over the entire neonatal period. Data were analyzed using the Friedman analysis of variance for comparative analysis of study points.

RESULTS

Urinary NT-proBNP/creatinine ratios were significantly elevated on days 1 to 7 (mean 2,452, ± 1,518) than day 14 (mean 747, ± 176), and day 28 (mean 149, ± 54), p = 0.001. Overall, urinary NT-proBNP levels were highest during days 1 to 3 (mean 3,232, ± 1,255) and lowest on day 28 (mean 149, ± 54).

CONCLUSION

Urinary NT-proBNP levels are higher during the first week in ELBW infants with a downward trend during the neonatal period, the lowest values at 4 weeks postnatal age. More studies are required to determine the clinical utility of this trend during and beyond the neonatal period.

KEY POINTS

· NT-proBNP is a biomarker for monitoring cardiac disease in premature infants.. · The trend of urinary NT-proBNP is unknown in premature infants.. · A trend of urinary NT-proBNP was determined during the first 4 weeks in premature infants..

High-sensitivity cardiac troponins in pediatric population

Apparently healthy children often complain of chest pain, especially after physical exercise. Cardiac biomarker levels are often measured, but the clinical relevance of these assays in children is still debated, even when a cardiac disease is present. Coronary artery disease is exceedingly rare in children, but elevated circulating levels of cardiac troponin I (cTnI) and T (cTnT) in an acute setting may help detect heart failure due to an unknown cardiac disorder, or worsening heart failure, particularly in combination with other biomarkers such as B-type natriuretic peptides. However, the interpretation of biomarkers is often challenging, especially when institutions transition from conventional cTn assays to high-sensitivity (hs-cTn) methods, as well demonstrated in the emergency setting for adult patients. From a clinical perspective, the lack of established reference values in the pediatric age is the main problem limiting the use of hs-cTn methods for the diagnosis and managements of cardiac diseases in infants, children and adolescents. This review aims to discuss the possibility to use hs-cTnI and hs-cTnT to detect cardiac disease and to explore age-related differences in biomarker levels in the pediatric age. We start from some analytical and pathophysiological considerations related to hs-cTn assays. Then, after a systematic literature search, we discuss the current evidence and possible limitations of hs-cTn assay as indicators of cardiac disease in the most frequently cardiac disease in pediatric setting.

Risk factors of postoperative low cardiac output syndrome in children with congenital heart disease: A systematic review and meta-analysis

BACKGROUND

Low cardiac output syndrome (LCOS) is the most common complication after cardiac surgery, which is associated with the extension of postoperative hospital stay and postoperative death in children with congenital heart disease (CHD). Although there are some studies on the risk factors of LCOS in children with CHD, an unified conclusion is lack at present.

PURPOSES

To synthesize the risk factors of LCOS after CHD in children, and to provide evidence-based insights into the early identification and early intervention of LCOS.

METHODS

The databases of the China National Knowledge Infrastructure (CNKI), Wanfang Database, China Science and Technology Journal Database (VIP), PubMed, Cochrane Library, Embase and Web of Science were searched for relevant articles that were published between the establishing time of each database and January 2022. Based on retrospective records or cohort studies, the influencing factors of postoperative low cardiac output in children with congenital heart disease were included in Meta analysis.This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The risk of bias was evaluated according to the Newcastle-Ottawa Scale (NOS). RevMan 5.4 software was used to conduct the meta-analysis.

RESULTS

A total of 1,886 records were screened, of which 18 were included in the final review. In total, 37 risk factors were identified in the systematic review. Meta- analysis showed that age, type of CHD, cardiac reoperation, biventricular shunt before operation, CPB duration, ACC duration, postoperative residual shunt, cTn-1 level 2 h after CPB > 14 ng/ml and postoperative 24 h MR-ProADM level > 1.5 nmol/l were independent risk factors of LCOS. Additionally, the level of blood oxygen saturation before the operation was found to have no statistically significant relationship with LOCS.

CONCLUSION

The risk factors of postoperative LCOS in children with CHD are related to disease condition, intraoperative time and postoperative related indexes, so early prevention should be aimed at high-risk children.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022323043.

Levosimendan Versus Milrinone and Release of Myocardial Biomarkers After Pediatric Cardiac Surgery: Post Hoc Analysis of Clinical Trial Data

OBJECTIVES

We compared the effect of two inodilators, levosimendan and milrinone, on the plasma levels of myocardial injury biomarkers, that is, high-sensitivity troponin T and heart-type fatty acid binding protein, and on N-terminal prohormone of brain natriuretic peptide as a biomarker of ventricular function. We hypothesized that levosimendan could attenuate the degree of myocardial injury when compared with milrinone.

DESIGN

A post hoc, nonprespecified exploratory secondary analysis of the Milrinone versus Levosimendan-1 trial (ClinicalTrials.gov Identifier: NCT02232399).

SETTING

Two pediatric tertiary university hospitals.

PATIENTS

Infants 1-12 months old, diagnosed with ventricular septal defect, complete atrioventricular septal defect, or Tetralogy of Fallot undergoing corrective surgery with cardiopulmonary bypass.

INTERVENTIONS

Seventy patients received a loading dose of either levosimendan or milrinone at the start of cardiopulmonary bypass followed by an infusion of the respective drug, which continued for 26 hours.

MEASUREMENTS AND MAIN RESULTS

Plasma levels of the three cardiac biomarkers were measured prior to the initiation of cardiopulmonary bypass and 2, 6, and 24 hours after weaning from cardiopulmonary bypass. In both groups, the levels of high-sensitivity troponin T and heart-type fatty acid binding protein were highest at 2 hours post cardiopulmonary bypass, whereas the highest level of N-terminal prohormone of brain natriuretic peptide occurred at 24 hours post cardiopulmonary bypass. There was no significant difference in the biomarkers' plasma levels between the study groups over time. Neither was there a significant difference in the postoperative peak plasma levels of the cardiac biomarkers.

CONCLUSIONS

In this post hoc analysis of the MiLe-1 trial, there was no demonstrable difference in the postoperative cardiac biomarker profile of myocardial injury and ventricular function when comparing infants managed in the perioperative period with levosimendan versus milrinone.

Cardiac Biomarkers in Pediatrics: An Undervalued Resource

BACKGROUND

The clinical use of common cardiac biomarkers, such as brain natriuretic peptides and troponins, has traditionally been limited to adult populations in the assessment of heart failure and acute coronary syndrome, respectively. While many have discounted the value of these markers in pediatric populations, emerging evidence suggests they may be useful in the diagnosis and prognostication of many cardiac and noncardiac pathologies in neonates, children, and adolescents, and an increasing number of pediatric hospitals are routinely measuring cardiac markers in their clinical practice.

CONTENT

This review summarizes and critically evaluates the current literature regarding the application of cardiac biomarkers for clinical decision-making in the pediatric population. Main potential clinical indications discussed herein include primary cardiac disease, immune-related conditions, and noncardiac disease. Important diagnostic and interpretative challenges are also described in relation to each potential indication.

SUMMARY

Despite a general lack of clinical awareness regarding the value of cardiac biomarkers in pediatrics, there is increasing literature to support their application in various contexts. Cardiac biomarkers should be considered an undervalued resource in the pediatric population with potential value in the diagnosis and prognosis of myocarditis, congenital heart disease, and heart failure, as well as in the assessment of severity and cardiac involvement in immune-related and other systemic conditions. While interpretation remains challenging in pediatrics due to the age- and sex-specific dynamics occurring throughout growth and development, this should not prevent their application. Future research should focus on defining evidence-based cut-offs for specific indications using the most up-to-date assays.

Clinical and Laboratory Predictors for the Development of Low Cardiac Output Syndrome in Infants Undergoing Cardiopulmonary Bypass: A Pilot Study

Cardiac surgery employing cardiopulmonary bypass exposes infants to a high risk of morbidity and mortality. The objective of this study was to assess the utility of clinical and laboratory variables to predict the development of low cardiac output syndrome, a frequent complication following cardiac surgery in infants. We performed a prospective observational study in the pediatric cardiovascular ICU in an academic children’s hospital. Thirty-one patients with congenital heart disease were included. Serum levels of nucleosomes and a panel of 20 cytokines were measured at six time points in the perioperative period. Cardiopulmonary bypass patients were characterized by increased levels of interleukin-10, -6, and -1α upon admission to the ICU compared to non-bypass cardiac patients. Patients developing low cardiac output syndrome endured longer aortic cross-clamp time and required greater inotropic support at 12 h postoperatively compared to bypass patients not developing the condition. Higher preoperative interleukin-10 levels and 24 h postoperative interleukin-8 levels were associated with low cardiac output syndrome. Receiver operating characteristic curve analysis demonstrated a moderate capability of aortic cross-clamp duration to predict low cardiac output syndrome but not IL-8. In conclusion, low cardiac output syndrome was best predicted in our patient population by the surgical metric of aortic cross-clamp duration.

Risk Factors for Cardiac Adverse Events in Infants and Children with Complex Heart Disease Scheduled for Bi-ventricular Repair: Prognostic Value of Pre-operative B-Type Natriuretic Peptide and High-Sensitivity Troponin T

Few reports have described the prognostic value of measuring both B-type natriuretic peptides (BNP) and high-sensitivity troponin T (hs-TnT) in pediatric patients with complex congenital heart disease (CHD) undergoing surgery. We assessed demographic, hemodynamic, and laboratory data, including BNP and hs-TnT levels, for the prediction of cardiac adverse events in 85 patients. Cardiac adverse events were defined as death, cardiac arrest, worsening heart failure requiring inotropic agents and/or respiratory support, and unscheduled surgery/intervention either within or after 12 months of surgery. There were 17 cardiac adverse events. Of the demographic variables, low birth weight (< 2500 g: Odds ratio [OR], 5.97; 95% confidential interval [CI] 1.48-24.0; p = 0.001) and Ross/New York Heart Association [NYHA] class (≥ 2.0) (OR 12.7; 95% CI 3.08-52.7; p = 0.0004) were strongly association with cardiac adverse events. Among hemodynamic and laboratory variables, preoperative BNP (OR 14.04; 95% CI 2.15-91.7; p = 0.001) and hs-TnT levels (OR 16.66; 95% CI 2.27-122; p = 0.002) were found to be independent risk factors. Receiver operating characteristic analysis determined BNP and hs-TnT levels of 60.9 pg/mL and 0.025 ng/mL, respectively, to be markers of high risk. Kaplan-Meier analysis demonstrated significant differences in the freedom from cardiac adverse events between Group A (BNP or hs-TnT elevated, n = 26) and Group B (both biomarkers elevated, n = 19; log-rank, p < 0.001). In conclusion, low birth weight (< 2500 g) and Ross/NYHA class ≥ 2.0 are strongly associated with cardiac adverse events. Preoperative BNP and hs-TnT also provide prognostic information in patients with complex CHD scheduled for surgery. Using both markers in combination predicts cardiac adverse events better than using either separately.

Early assessment of cardiac troponin I predicts the postoperative cardiac status and clinical course after congenital heart disease surgery

Cardiac troponin I (cTnI) is a regulatory protein with a high sensitivity and specificity for cardiac injury. Preoperative and postoperative elevations of cTnI are usually considered predictors of the mortality and morbidity. However, little is known about the relationship between the cTnI and postoperative course after the congenital heart disease (CHD) operation. Sixty-five consecutive patients who underwent cardiac surgery for CHD at our institution between March 2016 and January 2017 were included. The cTnI was measured after the operation. Also, the association between the cTnI and duration of the catecholamine use, ICU stay, aortic cross clamp time, and other clinical parameters were assessed. The cTnI level on postoperative day 1 was positively correlated with the duration of the catecholamine use (p < 0.001) and ICU stay (p < 0.001). Also, a higher cTnI level was associated with a lower urine volume and higher lactate level 24 h after the ICU admission. In the multivariable regression analysis, the cTnI was a significant independent predictor of the catecholamine use (p = 0.002) and ICU stay (p = 0.003). The cTnI level on postoperative day 1 was a predictor of the duration of the catecholamine use and ICU stay.

Spontaneous Breathing Trial for Prediction of Extubation Success in Pediatric Patients Following Congenital Heart Surgery: A Randomized Controlled Trial

OBJECTIVES

To evaluate the usefulness of a spontaneous breathing trial for predicting extubation success in pediatric patients in the postoperative period after cardiac surgery compared with a physician-led weaning.

STUDY DESIGN

Randomized, controlled trial.

SETTING

PICU of a tertiary-care university hospital.

PATIENTS

A population of pediatric patients following cardiac surgery for congenital heart disease.

INTERVENTIONS

Patients on mechanical ventilation for more than 12 hours after surgery who were considered ready for weaning were randomized to the spontaneous breathing trial group or the control group. The spontaneous breathing trial was performed on continuous positive airway pressure with the pressure support of 10 cmH2O, the positive end-expiratory pressure of 5 cmH2O, and the fraction of inspired oxygen less than or equal to 0.5 for 2 hours. Patients in the control group underwent ventilator weaning according to clinical judgment.

MEASUREMENTS AND MAIN RESULTS

The primary endpoint was extubation success defined as no need for reintubation within 48 hours after extubation. Secondary outcomes were PICU length of stay, hospital length of stay, occurrence rate of ventilator-associated pneumonia, and mortality. One hundred and ten patients with the median age of 8 months were included in the study: 56 were assigned to the spontaneous breathing trial group and 54 were assigned to the control group. Demographic and clinical data and Risk Adjustment for Congenital Heart Surgery-1 classification were similar in both groups. Patients undergoing the spontaneous breathing trial had greater extubation success (83% vs 68%, p = 0.02) and shorter PICU length of stay (median 85 vs 367 hr, p < 0.0001) compared with the control group, respectively. There was no significant difference between groups in hospital length of stay, occurrence rate of ventilator-associated pneumonia, and mortality.

CONCLUSIONS

Pediatric patients with congenital heart disease undergoing the spontaneous breathing trial postoperatively had greater extubation success and shorter PICU length of stay compared with those weaned according to clinical judgment.

Neutrophil extracellular traps (NETs) exacerbate severity of infant sepsis

Background

Neutrophil extracellular traps (NETs) are innate defense mechanisms that are also implicated in the pathogenesis of organ dysfunction. However, the role of NETs in pediatric sepsis is unknown.

Methods

Infant (2 weeks old) and adult (6 weeks old) mice were submitted to sepsis by intraperitoneal (i.p.) injection of bacteria suspension or lipopolysaccharide (LPS). Neutrophil infiltration, bacteremia, organ injury, and concentrations of cytokine, NETs, and DNase in the plasma were measured. Production of reactive oxygen and nitrogen species and release of NETs by neutrophils were also evaluated. To investigate the functional role of NETs, mice undergoing sepsis were treated with antibiotic plus rhDNase and the survival, organ injury, and levels of inflammatory markers and NETs were determined. Blood samples from pediatric and adult sepsis patients were collected and the concentrations of NETs measured.

Results

Infant C57BL/6 mice subjected to sepsis or LPS-induced endotoxemia produced significantly higher levels of NETs than the adult mice. Moreover, compared to that of the adult mice, this outcome was accompanied by increased organ injury and production of inflammatory cytokines. The increased NETs were associated with elevated expression of Padi4 and histone H3 citrullination in the neutrophils. Furthermore, treatment of infant septic mice with rhDNase or a PAD-4 inhibitor markedly attenuated sepsis. Importantly, pediatric septic patients had high levels of NETs, and the severity of pediatric sepsis was positively correlated with the level of NETs.

Conclusion

This study reveals a hitherto unrecognized mechanism of pediatric sepsis susceptibility and suggests that NETs represents a potential target to improve clinical outcomes of sepsis.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2407-8) contains supplementary material, which is available to authorized users.

Use of Levosimendan in Postoperative Setting After Surgical Repair of Congenital Heart Disease in Children

Low cardiac output is one of the most common complications after cardiac surgery. Levosimendan, a new inotrope agent, has been demonstrated in adult patient to be an effective treatment for this purpose when classical therapy is not effective. The aim of this study was to evaluate the effect of Levosimendan on cardiac output parameters in cardiac children with low cardiac output syndrome (LCOS.). We carried out a retrospective analysis on 62 children hospitalized in our pediatric intensive care unit (PICU) after cardiac surgery, which demonstrated LCOS not responding to classical catecholamine therapy and who received levosimendan as rescue therapy. LCOS parameters like diuresis, central venous oxygen saturation (SvO₂), venous-to-arterial CO₂ difference (∆avCO₂), and plasmatic lactate were compared before therapy and at 3, 6, 12, and 24 h after the beginning of the levosimendan infusion. We also analyzed the effect on the Vasoactive-inotropic score (VIS), adverse events, and mortality. After the beginning of levosimendan infusion, diuresis (1.1 vs. 3.5 ml/kg/h, p = 0.001) and SvO₂ (59.5 vs. 63.3%, p = 0.026) increased significantly during the 24 h of infusion, and at the same time, plasmatic lactate (2.3 vs. 1.3 mmol/l, p < 0.001) decreased. ∆avCO₂ (10.8 vs. 9.4 mmHg, p = 0.21) and the VIS (44.5 vs. 22.5, p = 0.143) also decreased, but not significantly. No side effects were noted. The mortality in this patient group was 16%. Levosimendan is an effective treatment in children presenting LCOS after congenital heart surgery. Our study confirms the improvement of cardiac output already shown in other pediatric studies, with no undesirable side effects.

Severe pertussis infection: A clinicopathological study

We aimed to investigate the clinicopathological features of pertussis in children admitted to a tertiary-care university hospital in Brazil.This was a retrospective cohort study of all pediatric hospital admissions with pertussis from January 1, 2008 to December 31, 2014. We also reported the autopsy findings in children who died.Fifty-five patients admitted to the hospital over the study period had laboratorial confirmation of Bordetella pertussis infection, 17 (30.9%) needed pediatric intensive care unit (PICU) admission and 6 (10.9%) died. All patients who died were younger than 60 days old and unvaccinated for pertussis; 50% of them had coinfection with respiratory syncytial virus. Leukocyte count ≥40,000/mm at hospital admission was an independent risk factor for PICU admission. Mean heart rate during hospitalization ≥160 bpm was an independent risk factor for death. A cut-off point of 41,200 leukocytes/mm at hospital admission had sensitivity of 64.7% and specificity of 89.5% to predict PICU admission (area under the curve 0.75) and sensitivity of 100% and specificity of 81.6% to predict death (area under the curve 0.93). Autopsy showed medial thickening of small pulmonary arteries in 80% of patients who had pulmonary hypertension; intravascular aggregates of leukocytes or pulmonary thrombosis were not observed. Immunohistochemical staining of tissue samples obtained at autopsy identified B pertussis and respiratory syncytial virus in pulmonary and extra-pulmonary sites.Marked leukocytosis at presentation was associated with morbidity and mortality in children hospitalized with pertussis. Implementation of preventive strategies is crucial to diminish the incidence of the disease, especially in young unimmunized infants.

Increased Atrial β-Adrenergic Receptors and GRK-2 Gene Expression Can Play a Fundamental Role in Heart Failure After Repair of Congenital Heart Disease with Cardiopulmonary Bypass

Surgeries to correct congenital heart diseases are increasing in Brazil and worldwide. However, even with the advances in surgical techniques and perfusion, some cases, especially the more complex ones, can develop heart failure and death. A retrospective study of patients who underwent surgery for correction of congenital heart diseases with cardiopulmonary bypass (CPB) in a university tertiary-care hospital that died, showed infarction in different stages of evolution and scattered microcalcifications in the myocardium, even without coronary obstruction. CPB is a process routinely used during cardiac surgery for congenital heart disease. However, CPB has been related to increased endogenous catecholamines that can lead to major injuries in cardiomyocytes. The mechanisms involved are not completely understood. The aim of this study was to evaluate the alterations induced in the β-adrenergic receptors and GRK-2 present in atrial cardiomyocytes of infants with congenital heart disease undergoing surgical repair with CPB and correlate the alterations with functional and biochemical markers of ischemia/myocardial injury. The study consisted of right atrial biopsies of infants undergoing surgical correction in HC-FMRPUSP. Thirty-three cases were selected. Atrial biopsies were obtained at the beginning of CPB (group G1) and at the end of CPB (group G2). Real-time PCR, Western blotting, and immunofluorescence analysis were conducted to evaluate the expression of β₁, β₂-adrenergic receptors, and GRK-2 in atrial myocardium. Cardiac function was evaluated by echocardiography and biochemical analysis (N-terminal pro-brain natriuretic peptide (NT-ProBNP), lactate, and cardiac troponin I). We observed an increase in serum lactate, NT-proBNP, and troponin I at the end of CPB indicating tissue hypoxia/ischemia. Even without major clinical consequences in cardiac function, these alterations were followed by a significant increase in gene expression of β₁ and β₂ receptors and GRK-2, suggesting that this is one of the mechanisms responsible for the exacerbated response of cardiomyocytes to circulating catecholamines. These alterations could explain the irreversible myocardial damage and lipid peroxidation of membranes classically attributed to catecholamine excess, observed in some infants who develop heart failure and postoperative death. Although other factors may be involved, this study confirms that CPB acts as a potent inducer of increased gene expression of β- adrenergic receptors and GRK-2, making the myocardium of these infants more susceptible to the effects of circulating endogenous catecholamines, which may contribute to the development of irreversible myocardial damage and death.

Biomarkers in Pediatric Cardiac Critical Care

OBJECTIVES

In this review, we discuss the physiology, pathophysiology, and clinical role of troponin, lactate, and B-type natriuretic peptide in the assessment and management of children with critical cardiac disease.

DATA SOURCE

MEDLINE, PubMed.

CONCLUSION

Lactate, troponin, and B-type natriuretic peptide continue to be valuable biomarkers in the assessment and management of critically ill children with cardiac disease. However, the use of these markers as a single measurement is handicapped by the wide variety of clinical scenarios in which they may be increased. The overall trend may be more useful than any single level with a persistent or rising value of more importance than an elevated initial value.

Epidemiology and Outcome of Acute Kidney Injury According to Pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease and Kidney Disease: Improving Global Outcomes Criteria in Critically Ill Children-A Prospective Study

OBJECTIVE

We aimed to investigate the epidemiology, risk factors, and short- and medium-term outcome of acute kidney injury classified according to pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease, and Kidney Disease: Improving Global Outcomes criteria in critically ill children.

DESIGN

Prospective observational cohort study.

SETTING

Two eight-bed PICUs of a tertiary-care university hospital.

PATIENTS

A heterogeneous population of critically ill children.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Demographic, clinical, laboratory, and outcome data were collected on all patients admitted to the PICUs from August 2011 to January 2012, with at least 24 hours of PICU stay. Of the 214 consecutive admissions, 160 were analyzed. The prevalence of acute kidney injury according to pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease and Kidney Disease: Improving Global Outcomes criteria was 49.4% vs. 46.2%, respectively. A larger proportion of acute kidney injury episodes was categorized as Kidney Disease: Improving Global Outcomes stage 3 (50%) compared with pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease F (39.2%). Inotropic score greater than 10 was a risk factor for acute kidney injury severity. About 35% of patients with acute kidney injury who survived were discharged from the PICU with an estimated creatinine clearance less than 75 mL/min/1.73 m and one persisted with altered renal function 6 months after PICU discharge. Age 12 months old or younger was a risk factor for estimated creatinine clearance less than 75 mL/min/1.73 m at PICU discharge. Acute kidney injury and its severity were associated with increased PICU length of stay and longer duration of mechanical ventilation. Eleven patients died; nine had acute kidney injury (p < 0.05). The only risk factor associated with death after multivariate adjustment was Pediatric Risk of Mortality score greater than or equal to 10.

CONCLUSIONS

Acute kidney injury defined by both pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease and Kidney Disease: Improving Global Outcomes criteria was associated with increased morbidity and mortality, and may lead to long-term renal dysfunction.

Clinical utility of B-type natriuretic peptide (NP) in pediatric cardiac surgery--a systematic review

BACKGROUND

NP is a biomarker that has been used in the diagnosis, management, and prognostication of a number of cardiovascular disorders in the pediatric population. The physiological role of this hormone is to allow the myocardium to adapt to stress or strain imposed by a volume and/or pressure load.

OBJECTIVE

The aim of this study was to determine the utility of preoperative and postoperative NP to predict outcome in pediatric patients undergoing cardiac surgery for structural congenital heart disease.

METHOD

We conducted a systematic review by searching three electronic databases using the search terms 'paediatric' or 'pediatric' and 'B-type natriuretic peptide'. Twenty peer-reviewed papers were included in the study.

RESULTS

Preoperative NP levels were associated with the severity of cardiac failure in several studies. Preoperative NPs also correlated with early postoperative outcome measures such as duration of cardiopulmonary bypass, duration of mechanical ventilation, presence of low cardiac output syndrome, length of stay in the intensive care unit and in one study, death. Early (within 24 h) postoperative NPs showed a stronger correlation than preoperative NPs to early postoperative adverse events.

CONCLUSION

NPs provide a simple, noninvasive and complementary tool to echocardiography that can be used to assist clinicians in the assessment and management of pediatric patients with congenital heart disease in the perioperative period.

Low preoperative cholesterol level is a risk factor of sepsis and poor clinical outcome in patients undergoing cardiac surgery with cardiopulmonary bypass

OBJECTIVES

Systemic inflammatory response syndrome and sepsis frequently occur after cardiac surgery with cardiopulmonary bypass. The aim of the present study was to investigate whether preoperative cholesterol levels can predict sepsis onset and postoperative complications in patients undergoing cardiac surgery with cardiopulmonary bypass.

DESIGN

Prospective observational study.

SETTING

Surgical ICU of a French university hospital.

PATIENTS

Two hundred and seventeen consecutive patients older than 18 years admitted for planned cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

Measurements of plasma blood lipids and inflammation markers before anesthesia induction (baseline), at cardiopulmonary bypass start, at cardiopulmonary bypass end, and 3 and 24 hours after cardiac surgery. Outcomes were compared in systemic inflammatory response syndrome patients with sepsis (n = 15), systemic inflammatory response syndrome patients without sepsis (n = 95), and non-systemic inflammatory response syndrome patients (n = 107).

MEASUREMENTS AND MAIN RESULTS

A gradual decrease in plasma cholesterol concentration occurred during surgery with cardiopulmonary bypass but was no longer present after correction for hemodilution. Corrected cholesterol levels were significantly lower at baseline in sepsis patients than in other subgroups, and it remained lower in the sepsis group during and after cardiopulmonary bypass. With regard to sepsis, the discriminatory power of baseline cholesterol was fairly good as indicated by receiver operating characteristic curve analysis (area under the curve, 0.78; 95% CI, 0.72-0.84). The frequency of sepsis progressively decreased with increasing baseline cholesterol level quintiles (18.6% and 0% in the bottom and top quintiles, respectively, p = 0.005). In multivariate analysis, baseline cholesterol levels and cardiopulmonary bypass duration were significant and independent determinants of the 3-hour postcardiopulmonary bypass increase in concentrations of procalcitonin and interleukin-8, but not of interleukin-6.

CONCLUSIONS

Low cholesterol levels before elective cardiac surgery with cardiopulmonary bypass may be a simple biomarker for the early identification of patients with a high risk of sepsis.

Cardiopulmonary bypass is associated with hemolysis and acute kidney injury in neonates, infants, and children*

OBJECTIVES

This pilot study assesses the degree of hemolysis induced by cardiopulmonary bypass and determines its association with acute kidney injury in pediatric patients. Further, it evaluates the degree to which the use of urinary biomarkers neutrophil gelatinase-associated lipocalin and cystatin C correlate with the presence of acute kidney injury and hemolysis following cardiopulmonary bypass.

DESIGN

Prospective observational study.

SETTING

A 13-bed pediatric cardiac ICU in a university hospital.

PATIENTS

Children undergoing cardiac surgery with the use of cardiopulmonary bypass.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Blood and urine samples were obtained at multiple time points before and after cardiopulmonary bypass. Hemolysis was assessed by measuring levels of plasma hemoglobin and haptoglobin. Acute kidney injury was defined as a doubling in serum creatinine from preoperative baseline and by using the pediatric-modified RIFLE criteria. Urinary neutrophil gelatinase-associated lipocalin and cystatin C levels were measured. A total of 40 patients (range, 3 d to 4.8 yr) were enrolled. Plasma hemoglobin levels increased markedly on separation from cardiopulmonary bypass with a concurrent decrease in haptoglobin. This was associated with an increase in protein oxidation in the plasma. Hemolysis was more evident in younger patients with a longer duration of bypass and in those requiring a blood-primed circuit. Forty percent of patients had a doubling in serum creatinine and acute kidney injury was developed in 88% of patients when defined by the pediatric-modified RIFLE criteria. Controlling for cardiopulmonary bypass time, persistently elevated levels of plasma hemoglobin were associated with a five-fold increase in acute kidney injury. Further, urinary neutrophil gelatinase-associated lipocalin measured 2 hours after separation from cardiopulmonary bypass was associated with acute kidney injury and with elevations in plasma hemoglobin.

CONCLUSIONS

Cardiopulmonary bypass in pediatric patients results in significant hemolysis, which is associated with the development of acute kidney injury. The biomarker neutrophil gelatinase-associated lipocalin correlates with both acute kidney injury and hemolysis in this population.

Impact of anesthesia and surgery for congenital heart disease on the vitamin d status of infants and children: a prospective longitudinal study

BACKGROUND

Vitamin D is recognized as a pleiotropic hormone important for the functioning of organ systems, including those central to critical illness pathophysiology. Recent studies have reported associations between vitamin D status and outcome among critically ill adults and children. Preoperative vitamin D status, impact of operative techniques, and relationship between immediate postoperative vitamin D levels and clinical course have not been described in the pediatric congenital heart disease (CHD) population. The objective of this study was to describe the impact of CHD surgery on vitamin D status and relationship between postoperative levels and clinical course.

METHODS

A prospective cohort study was conducted from 2009 to 2011 at a single tertiary care pediatric hospital. A total of 58 children with CHD were enrolled and blood collected preoperatively, intraoperatively, and postoperatively. Serum 25-hydroxyvitamin D (25OHD) was measured using liquid chromatography-mass spectrometry.

RESULTS

The mean preoperative 25OHD was 58.0 nM (SD, 22.4), with 42% being deficient (<50 nM). Postoperatively, we identified a 40% decline in 25OHD to 34.2 nM (SD, 14.5) with 86% being deficient. Intraoperative measurements determined that initiation of cardiopulmonary bypass coincided with abrupt decline. CHD patients requiring catecholamines had lower postoperative 25OHD (38.2 vs. 26.5 nM, P=0.007), findings confirmed through multivariate logistic regression. Lower postoperative 25OHD was associated with increased fluid requirements and intubation duration.

CONCLUSIONS

Most CHD patients are vitamin-D deficient postoperatively due to low preoperative levels and a significant intraoperative decline. Interventional studies will be required to determine whether prevention of postoperative vitamin D deficiency improves outcome.

Cardiac troponin I after cardiopulmonary bypass in infants in comparison with older children

OBJECTIVE

At the present time, there is a trend towards performing open heart surgery at a younger age. Myocardium of infants has been thought to be more vulnerable to cardiopulmonary bypass in comparison with adults. For this study, we evaluated the degree of myocardial injury by measurement of cardiac troponin levels in infants in comparison with older children for similar surgeries.

METHODS

Serum was collected before bypass, after bypass, and daily after surgery and serum cardiac troponin I level (micrograms per litre). The demographic data, cardiac diagnoses, types of surgery performed, and peri-operative parameters were collected.

RESULTS

Of the 21 children enrolled consecutively, five were infants. Among the 21 patients, four patients had post-operative peak troponin values greater than 100 (three were infants) and all four patients survived and had normal left ventricular systolic function upon discharge echocardiogram. The five infants had peak troponin levels of 222.3, 202, 129, 26.7, and 82.3. The post-operative peak troponin levels were significantly higher in infants (mean 132.5 with a standard deviation of 81.6) than in the older children (mean 40.3 with a standard deviation of 33.4), although there was no significant difference in bypass time, bypass temperature, cross-clamp time, or the length of stay in the intensive care unit between the two age groups.

CONCLUSIONS

Higher troponin release is seen in infants in comparison with older children after bypass for similar surgeries. A troponin level greater than 100 after bypass does not necessarily predict death or a severe cardiovascular event in the very young.

Oxidative stress markers are not associated with outcomes after pediatric heart surgery

OBJECTIVES

To investigate whether perioperative serum levels of oxidative stress markers, thiobarbituric acid reactive substances (TBARS), and carbonyl moieties are associated with outcomes in children after heart surgery.

BACKGROUND

Oxidative stress markers are increased following heart surgery with cardiopulmonary bypass (CPB) and can play a role in ischemia-reperfusion injury, but its associations with myocardial dysfunction, low cardiac output syndrome (LCOS), and outcomes are not proven.

METHODS

In a retrospective secondary analysis of a cohort study comprising 55 children (median age, 109 [2-611] days), we compared pre-, intra- and postoperative serum levels of TBARS and carbonyl moieties among patients with and without postoperative LCOS, cyanotic and acyanotic congenital heart disease (CHD), and survivors and nonsurvivors. We also assessed the independent effect of TBARS and carbonyl moieties peak levels on the mortality-adjusted hospital length of stay (aLOS).

RESULTS

Patients who developed postoperative LCOS (n = 36) were significantly younger, more frequently cyanotic, more severely ill, and underwent more complex procedures with longer CPB. However, TBARS and carbonyl moieties serum levels did not change significantly over time. Moreover, they were not significantly different in patients with or without LCOS, cyanotic and acyanotic CHD, or survivors and nonsurvivors. There was a significant correlation between TBARS and tumor necrosis factor alpha (TNF-α) peak serum levels. Neither TBARS nor carbonyl moieties peak serum levels were independently associated with aLOS.

CONCLUSIONS

In conclusion, oxidative stress markers TBARS and carbonyl moieties were not associated with the development of LCOS, the aLOS, or mortality in children after heart surgery with CPB.

Adrenomedullin alterations related to cardiopulmonary bypass in infants with low cardiac output syndrome

BACKGROUND

Low cardiac output syndrome (LCOS) remains a major perioperative complications in infants subjected to open-heart surgery with cardiopulmonary bypass (CPB). The present study investigated whether perioperative blood assessment of a potent vasoactive peptide namely adrenomedullin (AM) can predict the risk of LCOS.

METHODS

We measured AM levels in 48 patients (LCOS: n = 9; controls: n = 39) undergone to open-heart surgery with CPB at five predetermined time points before, during and after the surgery. Clinical, laboratory and perioperative data were analyzed by a multiple logistic regression model.

RESULTS

AM significantly decreased (p < 0.01) during and after the surgical procedure exhibiting a dip at the end of the CPB. Multivariable analysis demonstrated significant correlations among LCOS, AM measured at the end of CPB (p < 0.001), and cooling duration (p < 0.05). AM at 27 pg/L cutoff achieved a sensitivity of 100% and a specificity of 64.1%, while cooling at 11-min cutoff combined a sensitivity of 55.6% and a specificity of 92.3% for LCOS prediction.

CONCLUSIONS

This study suggests that AM can constitute, alone or combined with standard parameters, a promising predictor of LCOS in infants subjected to open-heart surgery with CPB.

Early elevation of cardiac troponin I is predictive of short-term outcome in neonates and infants with coronary anomalies or reduced ventricular mass undergoing cardiac surgery

OBJECTIVE

The present study aimed to assess the usefulness of routine monitoring of cardiac troponin I concentrations within 24 hours of surgery (cTn-I<24h) in neonates and infants undergoing cardiac surgery.

METHODS

The added predictive ability of a high peak cTn-I<24h (within the upper quintile per procedure) for a composite outcome, including 30-day mortality and severe morbidity, was assessed retrospectively. The predicted risk for the composite outcome was estimated from a logistic regression model including preoperative and intraoperative variables. Adding a high peak cTn-I<24h to the risk model resulted in reclassification of the predicted risk. It also allowed quantification of the improvement in reclassification and discrimination by the difference between c-indexes, the Net Reclassification and the Integrated Discrimination Indexes (NRI and IDI).

RESULTS

Overall, 1023 consecutive patients were included. Adding a high peak cTn-I<24h to the model resulted in no improvement in reclassification or discrimination in the overall population (difference between c-indexes: 0.011 [-0.004 to 0.029], NRI = 0.06, P = .22, IDI = 0.02, P = .06), except in a subgroup of patients undergoing the arterial switch operation with or without ventricular septal defect closure and/or aortic arc repair, anomalous origin of the left coronary artery from the pulmonary artery repair, truncus arteriosus repair, Norwood procedure, and Sano modification, in whom NRI = 0.23 (P = .005) and IDI = 0.05 (P < .001).

CONCLUSIONS

Patients with coronary anomalies and patients with reduced ventricular mass should benefit from the routine monitoring of cTn-I concentrations after surgery for congenital cardiac disease.

Comparison of maximum vasoactive inotropic score and low cardiac output syndrome as markers of early postoperative outcomes after neonatal cardiac surgery

Low cardiac output syndrome (LCOS) and maximum vasoactive inotropic score (VIS) have been used as surrogate markers for early postoperative outcomes in pediatric cardiac surgery. The objective of this study was to determine the associations between LCOS and maximum VIS with clinical outcomes in neonatal cardiac surgery. This was a secondary retrospective analysis of a prospective randomized trial, and the setting was a pediatric cardiac intensive care unit in a tertiary care children's hospital. Neonates (n = 76) undergoing corrective or palliative cardiac operations requiring cardiopulmonary bypass were prospectively enrolled. LCOS was defined by a standardized clinical criteria. VIS values were calculated by a standard formula during the first 36 postoperative hours, and the maximum score was recorded. Postoperative outcomes included hospital mortality, duration of mechanical ventilation, intensive care unit (ICU) and hospital lengths of stay (LOS), as well as total hospital charges. At surgery, the median age was 7 days and weight was 3.2 kg. LCOS occurred in 32 of 76 (42%) subjects. Median maximum VIS was 15 (range 5-33). LCOS was not associated with duration of mechanical ventilation, ICU LOS, hospital LOS, and hospital charges. Greater VIS was moderately associated with a longer duration of mechanical ventilation (p = 0.001, r = 0.36), longer ICU LOS (p = 0.02, r = 0.27), and greater total hospital costs (p = 0.05, r = 0.22) but not hospital LOS (p = 0.52). LCOS was not associated with early postoperative outcomes. Maximum VIS has only modest correlation with duration of mechanical ventilation, ICU LOS, and total hospital charges.

Late remote ischemic preconditioning in children undergoing cardiopulmonary bypass: a randomized controlled trial

OBJECTIVE

Cardiopulmonary bypass is associated with ischemia-reperfusion injury to multiple organs. We aimed to evaluate whether remote ischemic preconditioning performed the day before surgery for congenital heart disease with cardiopulmonary bypass attenuates the postoperative inflammatory response and myocardial dysfunction.

METHODS

This was a prospective, randomized, single-blind, controlled trial. Children allocated to remote ischemic preconditioning underwent 4 periods of 5 minutes of lower limb ischemia by a blood pressure cuff intercalated with 5 minutes of reperfusion. Blood samples were collected 4, 12, 24, and 48 hours after cardiopulmonary bypass to evaluate nuclear factor kappa B activation in leukocytes by quantification of mRNA of I kappa B alpha by real-time quantitative polymerase chain reaction and for interleukin-8 and 10 plasma concentration measurements by enzyme-linked immunosorbent assay. Myocardial dysfunction was assessed by N-terminal pro-B-type natriuretic peptide and cardiac troponin I plasma concentrations, measured by chemiluminescence, and clinical parameters of low cardiac output syndrome.

RESULTS

Twelve children were allocated to remote ischemic preconditioning, and 10 children were allocated to the control group. Demographic data and Risk Adjustment for Congenital Heart Surgery 1 classification were comparable in both groups. Remote ischemic preconditioning group had lower postoperative values of N-terminal pro-B-type natriuretic peptide, but cardiac troponin I levels were not significantly different between groups. Interleukin-8 and 10 concentrations and I kappa B alpha gene expression were similar in both groups. Postoperative morbidity was similar in both groups; there were no postoperative deaths in either group.

CONCLUSIONS

Late remote ischemic preconditioning did not provide clinically relevant cardioprotection to children undergoing cardiopulmonary bypass.

Prevention for pediatric low cardiac output syndrome: results from the European survey EuLoCOS-Paed

OBJECTIVE

Characterize current hospital practices related to preventive drug therapy for low cardiac output syndrome (LCOS) in children with open heart surgery (OHS) in Europe.

METHODS

Web-based questionnaire survey of European hospitals performing OHS in children, conducted between January and August 2009.

RESULTS

Responses to the questionnaire were obtained from 90 of 125 hospitals (72.0%) from 31 different countries across the geographical European regions. The majority of hospitals (77.8%) administered preventive drug therapy and primarily targeted patients at risk (63.3%). Twenty-four different drug regimens were reported, involving 17 drugs from seven therapeutic drug classes. Milrinone, dopamine, epinephrine, dobutamine, and levosimendan made up 85.9% of the total drug use. Furthermore, milrinone was reported in 70.7% of all drug regimens and significantly more often in combination with other drugs than monotherapy (Δ20%, 95% CI 4.7-34.1%). Milrinone combination therapy reports included lower bolus but higher maintenance infusion doses than monotherapy reports. The timing of drug regimen administration varied across the full perioperative period, but drug regimens were mostly initiated during surgery and continued postoperatively.

CONCLUSION

Although current hospital practices related to preventive drug therapy for LCOS in children with OHS are characterized by a marked variability, only few drugs make up the bulk of prescribing practice with milrinone being most commonly used. Therefore, the survey provides information on which drugs to focus research and establish safe and effective drug use. A unified approach is urgently needed to ensure that children with OHS can benefit from evidence-based care.

Biomonitors of cardiac injury and performance: B-type natriuretic peptide and troponin as monitors of hemodynamics and oxygen transport balance

Serum biomarkers, such as B-type natriuretic peptide and troponin, are frequently measured in the cardiac intensive care unit. A review of the evidence supporting monitoring of these biomarkers is presented.

DESIGN

A search of MEDLINE, PubMed, and the Cochrane Database was conducted to find literature regarding the use of B-type natriuretic peptide and troponin in the cardiac intensive care setting. Adult and pediatric data were considered.

RESULTS AND CONCLUSION

Both B-type natriuretic peptide and troponin have demonstrated utility in the intensive care setting but there is no conclusive evidence at this time that either biomarker can be used to guide inpatient management of children with cardiac disease. Although B-type natriuretic peptide and troponin concentrations can alert clinicians to myocardial stress, injury, or hemodynamic alterations, the levels can also be elevated in a variety of clinical scenarios, including sepsis. Observational studies have demonstrated that perioperative measurement of these biomarkers can predict postoperative mortality and complications.

RECOMMENDATION AND LEVEL OF EVIDENCE

(class IIb, level of evidence B): The use of B-type natriuretic peptide and/or troponin measurements in the evaluation of hemodynamics and postoperative outcome in pediatric cardiac patients may be beneficial.

Early pleural effusions related to the myocardial injury after open-heart surgery for congenital heart disease

OBJECTIVES

The degree of effusion immediately after cardiopulmonary bypass (CPB) can vary and may reflect several factors including the degree of myocardial injury. We compared the degree of pleural effusions after CPB to the overall myocardial injury as determined by serum cardiac troponin I (cTnI) levels after elective repair of a variety of congenital heart defects, including univentricular surgeries via cavopulmonary shunts.

METHODS

Serum was collected pre-CPB, post-CPB, and daily after that and cTnI level measured. The postoperative pleural effusion was measured each day until the chest tube was removed. Results. The 21 study patients were of average age of 5.5 years (+/-5.6). The duration of chest-tube drainage after open-heart surgery was 4.3 days (+/-3.5) and the amount was 2.4 mL/kg/hour (+/-2.9). For the biventricular repairs, cTnI levels on the postoperative day (POD) 1 best correlated with amount of effusion (n = 16, r = 0.5, P = 0.02) and the average (POD 0-3) cTnI levels with the total duration (n = 16, r = 0.4, P = 0.01) and also the amount (n = 16, r = 0.5, P = 0.02) of effusions. For the cavopulmonary shunts, the post-CBP cTnI level best correlated with the duration (n = 5, r = 0.8, P = 0.02) and amount (n = 5, r = 0.9, P = 0.02) of effusions. A cTnI level on the first postoperative day >or=15 microg/L was associated with effusions >2 days (sensitivity of 81% and specificity of 80%).

CONCLUSION

We found that higher the cTnI released, especially >or=15 microg/L, longer the duration and greater the amount of early pleural effusions for a variety of congenital heart surgeries including cavopulmonary shunts. A number of factors may lead to excessive pleural effusions and the degree of myocardial injury may be one of them.

Strong relationship between NT-proXNP levels and cardiac output following cardiac surgery in neonates and infants

BACKGROUND

NT-proXNP, a new natriuretic peptide analyte, incorporates information about the concentrations of both N-terminal pro-atrial and pro-brain natriuretic peptides (NT-proANP, NT-proBNP). We aimed to investigate whether NT-proXNP is a reliable indicator of the cardiac index (CI) and the hemodynamic state in neonates and infants undergoing an open heart surgery.

METHODS

We enrolled 26 children under the age of 1 year into this prospective study. All patients underwent an elective cardiac operation with cardiopulmonary bypass (CPB) to achieve complete biventricular repair. Peri-operative hemodynamic parameters were assessed by transpulmonary thermodilution and natriuretic peptide levels were recorded.

RESULTS

The NT-proXNP level correlated significantly with the simultaneously measured NT-proANP level (r=0.60, P<0.001), but more strongly with the NT-proBNP level (r=0.89, P<0.001) and the arithmetic sum of both (r=0.88, P<0.001). NT-proXNP had a strong correlation with CI (r=-0.85, P<0.001), the stroke volume index (r=-0.80, P<0.001) and the global ejection fraction (r=-0.67, P<0.009) throughout the post-operative period. Conventionally measured parameters such as heart rate, mean arterial pressure and pulse-pressure product exhibited weaker correlations with CI than NT-proXNP. Among laboratory values, creatinine levels correlated significantly with CI (r=-0.77, P<0.001) and NT-proXNP (r=0.76, P<0.001) during the post-operative period. A post-operative NT-proXNP level of 3079 pmol/l was diagnostic for CI <3 l/min/m(2) with 89% sensitivity and 90% specificity (area under the curve: 0.91 +/- 0.05).

CONCLUSION

NT-proXNP is a good marker of cardiac output following pediatric cardiac surgery and might be a useful tool in the recognition of a low output state.

Ischemic myocardial injuries after cardiac malformation repair in infants may be associated with oxidative stress mechanisms

BACKGROUND

Despite advances in pediatric cardiac surgery, perioperative myocardial injury can be the major determinant of postoperative dysfunction after cardiac surgery. This study investigated the pathology-related differences in 29 infants with congenital heart disease that led to death. The infants were treated at the University Hospital of Ribeirão Preto, Brazil.

METHODS

The patients were divided into four groups: Group 1, 16 infants who underwent operations for congenital heart disease on cardiopulmonary bypass; Group 2, four infants who underwent off-cardiopulmonary bypass operations for congenital heart disease; Group 3, nine infants who died from congenital heart disease prior to surgical treatment; and Group 4 (control group), five infants with no congenital heart disease and who died from other causes. The myocardial injuries and oxidative stress mechanisms were assessed by histopathology and immunohistochemistry and were quantified by morphometrical analyses.

RESULTS

Contraction band necrosis and dystrophic calcification were found primarily in infants of Group 1. Coagulation necrosis and healing were prominent in Group 2, while infants without repair (Group 3) showed mainly colliquative myocytolysis. Apoptotic cells were more prominent in the operative groups. The control group showed no significant myocardial lesions. Lipid peroxidation was the principal mechanism of oxidative stress accounting for the myocardial lesions.

CONCLUSION

The diversity of the lesions observed in these hearts seemed to indicate a large spectrum of cell damage due to inadequate myocardial perfusion, especially when these infants underwent surgery. Oxidative mechanisms could be a common mediator in the pathogenesis of myocardial injuries, mediated by peroxidation of the membrane phospholipids and resulting in changes in the permeability of the cell membrane, cell death, and intracellular calcium overload. Furthermore, an immature and often hypertrophied myocardium may promote unfavorable conditions, leading to heart failure and a lethal outcome.

The Use of N-Terminal-Pro-BNP in Preterm Infants

The use of natriuretic peptides in the neonatal population is emerging. B-type Natriuretic Peptide (BNP) and N-terminal-Pro-BNP (NTpBNP) are used in the adult population to assess myocardial function and volume loading. Their role in prognosis following cardiac surgery has also been identified. In preterm infants NTpBNP is becoming increasingly recognised as a potential screening tool for patent ductus arteriosus (PDA), and a marker for myocardial performance. In addition, NTpBNP may provide prognostic information in preterm infants and term infants with congenital diaphragmatic hernia (CDH). In this paper, the role of NTpBNP in the preterm population will be discussed.