Preoperative lymphopenia is a predictor of postoperative adverse outcomes in children with congenital heart disease

Immune System Dysfunction Criteria in Critically Ill Children: The PODIUM Consensus Conference

CONTEXT

Immune system dysfunction is poorly represented in pediatric organ dysfunction definitions.

OBJECTIVE

To evaluate evidence for criteria that define immune system dysfunction in critically ill children and associations with adverse outcomes and develop consensus criteria for the diagnosis of immune system dysfunction in critically ill children.

DATA SOURCES

We conducted electronic searches of PubMed and Embase from January 1992 to January 2020, using medical subject heading terms and text words to define immune system dysfunction and outcomes of interest.

STUDY SELECTION

Studies of critically ill children with an abnormality in leukocyte numbers or function that is currently measurable in the clinical laboratory in which researchers assessed patient-centered outcomes were included. Studies of adults or premature infants, animal studies, reviews and commentaries, case series (≤10 subjects), and studies not published in English with inability to determine eligibility criteria were excluded.

DATA EXTRACTION

Data were abstracted from eligible studies into a standard data extraction form along with risk of bias assessment by a task force member.

RESULTS

We identified the following criteria for immune system dysfunction: (1) peripheral absolute neutrophil count <500 cells/μL, (2) peripheral absolute lymphocyte count <1000 cells/μL, (3) reduction in CD4+ lymphocyte count or percentage of total lymphocytes below age-specific thresholds, (4) monocyte HLA-DR expression <30%, or (5) reduction in ex vivo whole blood lipopolysaccharide-induced TNFα production capacity below manufacturer-provided thresholds.

LIMITATIONS

Many measures of immune system function are currently limited to the research environment.

CONCLUSIONS

We present consensus criteria for the diagnosis of immune system dysfunction in critically ill children.

Preoperative Neutrophil-Lymphocyte Ratio Can Predict Outcomes for Patients Undergoing Tetralogy of Fallot Repair

INTRODUCTION

Elevated neutrophil-lymphocyte ratio (NLR) has been associated with poorer outcomes in cyanotic patients undergoing single ventricle palliation. Little is known about this biomarker on patients with tetralogy of Fallot (TOF), the most common cyanotic congenital heart disease. Our objective is to study the impact of preoperative NLR on outcomes of TOF patients undergoing total repair.

METHODS

This retrospective study included 116 consecutive patients between January 2014 and December 2018. Preoperative NLR was measured from the last complete blood count test before the surgery. Using the cutoff value of 0.80, according to the receiver-operating characteristic (ROC) curve, the sample was divided into two groups (NLR < 0.80 and ≥ 0.80). The primary endpoint was hospital length of stay (LOS).

RESULTS

ROC curves showed that higher preoperative NLR was associated with longer hospital LOS, with an area under the curve of 0.801±0.040 (95% confidence interval 0.722 - 0.879; P<0.001). High preoperative NLR was also associated with long intensive care unit (ICU) LOS (P=0.035). Preoperative NLR predicted longer hospital LOS with a sensitivity of 63% and a specificity of 81.4%.

CONCLUSION

Higher preoperative NLR was associated with long ICU and hospital LOS in patients undergoing TOF repair.

Prognostic Value of Preoperative Absolute Lymphocyte Count in Children With Tetralogy of Fallot

Background

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease. Absolute lymphocyte count (ALC) is a low‐cost and easy‐to‐obtain inflammatory indicator; however, its association with the prognosis of patients with TOF remains unknown. This study aimed to determine the prognostic value of preoperative ALC in children with TOF.

Methods and Results

This retrospective study included 707 patients aged <6 years who underwent corrective operations for TOF between January 2016 and December 2018 in Fuwai Hospital, China. The end points were mortality, extracorporeal membrane oxygenation placement, postoperative hospital stay >30 days, and severe postoperative complications; patients were grouped on the basis of prognosis: poor prognosis (n=76) and good prognosis (n=631). Univariable and multivariable logistic regression analyses were performed to identify the independent risk factors for poor prognosis, on which a risk scoring system was based. The receiver operating characteristic curve was used to assess model performance. Using another model without ALC, the effect of the addition of ALC was assessed. Results suggested that ALC was an independent factor with a cutoff point of 4.36×10⁹/L. The addition of ALC improved the area under the curve from 0.771 to 0.781 (P<0.001). To avoid reverse causality and further control for confounding factors, the patients were further divided on the basis of ALC level, and a propensity score matching was performed; 117 paired patients were identified for further analysis. Low ALC levels had an odds ratio of 3.500 (95% CI, 1.413–8.672).

Conclusions

Low preoperative ALC represents an independent predictor of poor prognosis in children with TOF.

Cholinergic activity regulates the secretome of epicardial adipose tissue: Association with atrial fibrillation

Botulinum toxin injection on epicardial fat, which inhibits acetylcholine (ACh) release, reduced the presence of atrial fibrillation (AF) in patients after heart surgery. Thus, we wanted to study the profile of the released proteins of epicardial adipose tissue (EAT) under cholinergic activity (ACh treatment) and their value as AF predictors. Biopsies, explants, or primary cultures were obtained from the EAT of 85 patients that underwent open heart surgery. The quantification of muscarinic receptors (mAChR) by real-time polymerase chain reaction or western blot showed their expression in EAT. Moreover, mAChR Type 3 was upregulated after adipogenesis induction (p < 0.05). Cholinergic fibers in EAT were detected by vesicular ACh transporter levels and/or acetylcholinesterase activity. ACh treatment modified the released proteins by EAT, which were identified by nano-high-performance liquid chromatography and TripleTOF analysis. These differentially released proteins were involved in cell structure, inflammation, or detoxification. After testing the plasma levels of alpha-defensin 3 (inflammation-involved protein) of patients who underwent open heart surgery ( n = 24), we observed differential levels between the patients who developed or did not develop postsurgery AF (1.58 ± 1.61 ng/ml vs. 6.2 ± 5.6 ng/ml; p < 0.005). The cholinergic activity on EAT might suggest a new mechanism for studying the interplay among EAT, autonomic nervous system dysfunction, and AF.

Association of Preoperative Cell Counts With Outcomes After Operation for Congenital Heart Disease

BACKGROUND

We examined the association of preoperative cell count abnormalities, which have been shown to be associated with outcomes in adult cardiac patients, with morbidity and mortality after operation for congenital heart disease (CHD) in children.

METHODS

We performed a retrospective cohort study on 4,865 children undergoing cardiac operation from 2004 to 2014. Our exposures of interest were presence of preoperative lymphopenia (lymphocyte count ≤ 3,000 cells/μL), thrombocytopenia (platelet count < 150 × 10³/μL), and neutrophilia (neutrophil count ≥ 7,000 cells/μL). Our outcomes of interest were mortality status, postoperative length of stay (LOS), and occurrence of postoperative complications. We performed logistic and linear regressions to determine the associations of preoperative cell counts with mortality, LOS, and complications, adjusting for age, sex, race or ethnicity, presence of a genetic syndrome, and Society of Thoracic Surgeons and European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality category.

RESULTS

Overall mortality was 2.8%, median LOS was 6 days, and 7.6% of patients had postoperative complications. Lymphopenia was associated with increased odds of postoperative mortality (odds ratio 1.67, 95% confidence interval: 1.15 to 2.43, p = 0.007). Lymphopenia, thrombocytopenia, and neutrophilia were all associated with longer postoperative LOS. Lymphopenia and thrombocytopenia were associated with increased occurrence of postoperative sepsis, and neutrophilia was associated with need for postoperative mechanical circulatory support.

CONCLUSIONS

In children undergoing CHD operation, preoperative lymphopenia is associated with increased in-hospital mortality postoperatively. Preoperative lymphopenia, neutrophilia, and thrombocytopenia are associated with longer postoperative LOS and with development of postoperative complications. Preoperative cell counts may serve as important prognostic markers in preoperative planning for patients with CHD.

Vasoactive Inotropic Score (VIS) as Biomarker of Short-Term Outcomes in Adolescents after Cardiothoracic Surgery

Our aim was to evaluate the Vasoactive Inotropic Score (VIS) as a prognostic marker in adolescents following surgery for congenital heart disease. This single-center retrospective chart review included patients 10-18 years of age, who underwent cardiac surgery from 2009 to 2014. Hourly VIS was calculated for the initial 48 postoperative hours using standard formulae and incorporating doses of six pressors. The composite adverse outcome was defined as any one of death, resuscitation or mechanical support, arrhythmia, infection requiring antibacterial therapy, acute kidney injury or neurologic injury. Surgeries were risk-stratified by the type of surgical repair using the validated STAT score. Statistical analysis (SPSS 19.0) included Mann-Whitney U test, Chi-square test, ROC curves, and binary regression analysis. Our cohort (n = 149) had a mean (SD) age of 13.9 (2.4) years and included 97 (65.1 %) males. Maximal VIS at 24 and 48 h following surgery was significantly higher in subjects (n = 27) who suffered an adverse outcome. Subjects with adverse outcome had longer bypass and cross-clamp times, durations of stay in the hospital, and a higher rate of acute kidney injury, compared to those (n = 122) without postoperative adverse outcomes. The area under the ROC for maximum VIS at 24-48 h after surgery was 0.76, with sensitivity, specificity, and positive and negative predictive values with 95 % CI of 67 (48-82) %, 74 (70-77) %, and 36 (26-44) % and 91 (86-95) %, respectively, at a cutoff >4.75. On binary logistic regression, maximum VIS on second postoperative day remained significantly associated with adverse outcome (OR 1.35; 95 % CI> 1.12-1.64, p = 0.002). Maximal VIS at 24 and 48 h correlated significantly with length of stay and time to extubation. Maximal VIS on the second postoperative day predicts adverse outcome in adolescents following cardiac surgery. This simple yet robust prognostic indicator may aid in risk stratification and targeted interventions in this population.

Fungal infections and antifungal prophylaxis in pediatric cardiac extracorporeal life support

OBJECTIVE

Infections acquired by children during extracorporeal membrane oxygenation (ECMO) increase mortality. Our aim was to evaluate the effectiveness of prophylactic fluconazole on the incidence of fungal infections and to assess whether hospital-acquired fungal infection is associated with increased in-hospital mortality in pediatric cardiac patients requiring ECMO.

METHODS

We retrospectively reviewed a prospectively maintained database and collected data on all hospital-acquired infections in patients supported for cardiac indications at a tertiary children's hospital from 1989 to 2008.

RESULTS

ECMO was deployed 801 times in 767 patients. After exclusion criteria were applied, 261 pediatric patients supported for cardiac indications were studied. Fungal infection (blood, urine, or surgical site) occurred in 12% (31/261) of patients, 9 (7%) of 127 patients receiving fluconazole prophylaxis versus 22 (16.4%) of 134 without antifungal prophylaxis (P = .02). Using a multivariable logistic regression model, the absence of fluconazole prophylaxis was associated with an increased risk of fungal infection (odds ratio [OR] = 2.8; 95% confidence intervals [CI], 1.2, 6.7; P = .016). In a multivariable logistic regression model for in-hospital mortality, the presence of fungal infection was associated with increased odds (OR = 3.8; 95% CI, 1.5, 9.6; P = .005) of in-hospital mortality among cardiac patients requiring ECMO, and the absence of antifungal prophylaxis showed a trend toward the same (OR = 1.6; 95% CI, 0.96, 2.8; P = .072).

CONCLUSIONS

Children with cardiac disease supported with ECMO who acquire fungal infections have increased mortality. Routine fluconazole prophylaxis is associated with lower rates of fungal infections in these patients.

The outcome of open heart surgery for congenital heart disease in infants with low body weight less than 2500 g

Although the outcome of neonatal cardiac surgery has dramatically improved, low body weight (LBW) is still considered an important risk for open heart surgery. The factors contributing to poor outcomes in LBW infants, however, are still unclear. We investigated risk factors for poor outcomes in infants weighing <2500 g who underwent surgical correction with cardiopulmonary bypass (CPB). From January 1995 to December 2009, 102 consecutive patients were included in this study. Median age and body weight at the time of surgery was 19 (range 1 to 365) days and 2.23 kg (range 1.3 to 2.5), respectively. Corrective surgery was performed on 75 infants. The median follow-up duration was 45.03 months (range 0.33 to 155.23). There were 23 (22.5%) hospital mortalities. Emergency surgery and low cardiac output (LCO) were associated with early mortality; however, body weight, Aristotle basic complex score, and type of surgery was not. Early morbidities, including delayed sterna closure, arrhythmia, and chylothorax, occurred in 39 (38.2%) infants. The overall actuarial survival rate at 10 years was 74.95% ± 4.37%. In conclusion, among infants weighing <2500 g who underwent open heart surgery with CPB, perioperative hemodynamic status, such as emergency surgery and LCO, strongly influenced early mortality. In contrast, LBW itself was not associated with patient morbidity or mortality.

Nutrition assessment as a predictor of clinical outcomes for infants with cardiac surgery: using the prognostic nutritional index

BACKGROUND

The aim of the present study was to determine whether nutrition assessment helps predict clinical outcomes (COs) in infants who have undergone cardiac surgery.

METHODS

Study subjects were infants, aged less than 18 months, who had undergone cardiac surgery between April 2007 and August 2008. The nutrition parameters assessed include Onodera's prognostic nutritional index (PNI), height for age, weight for height, and weight for age. COs included mortality rate during hospitalization, length of stay in intensive care unit (LOS-1), length of stay in the hospital after surgery (LOS-2), and duration of mechanical ventilation support. Method-1: the correlation between nutrition parameters and COs was examined by statistical analysis. Method-2: the cutoff point of nutrition parameters was determined using the minimum P value approach.

RESULTS

The following results were obtained: Results-1: PNI was the only nutrition parameter found to be correlated with LOS-1. Results-2: the cutoff point for PNI as a predictor of LOS-1 was 55.

CONCLUSIONS

It appeared that preoperative PNI was the most influential factor on LOS-1 for infants after they underwent cardiac surgery. The PNI cutoff point 55 in infants who underwent cardiac surgery seems to be the best predictor of CO.

Nutritional challenges and outcomes after surgery for congenital heart disease

PURPOSE OF REVIEW

Adequate nutrition is crucial in children after surgery for congenital heart disease. We address selected nutritional and caloric requirements for children in the perioperative period before and after cardiac surgery and explore nutritional interdependence with other system functions. Recommendations based on our current practice are made at the end of each section.

RECENT FINDINGS

Early identification of deficient oropharyngeal motor skills and vocal cord dysfunction is crucial to establish enteral nutrition safely and has been demonstrated to improve clinical outcomes. The use of prealbumin as a marker of nutritional state should be accompanied by C-reactive protein given the influence of inflammation on its levels. Insulin infusions may improve outcomes in patients with postoperative hyperglycemia. Trace element abnormalities and early identification of immune-compromised states can aid in reducing morbidity in children after cardiac surgery. Use of feeding protocols and a home surveillance system for hypoplastic left heart syndrome improves outcomes.

SUMMARY

Adequate nutritional support in children after cardiac surgery is a challenge. Attention to lesion-specific feeding problems, supplementation of trace elements and minerals, and an organized approach to pace, timing, and type of feeding are beneficial.

Serum parameters and echocardiographic predictors of death or need for transplant in newborns, children, and young adults with heart failure

For children admitted with symptomatic heart failure (HF), the risk of death/need for transplantation (D/Tx) is high. Data from adult studies suggest serum measurements, such as percent lymphocytes, are valuable predictors of outcomes. The aim of this study was to identify risk factors for D/Tx in hospitalized pediatric patients with symptomatic HF. Retrospective analysis of children admitted to an academic center from January 1994 to June 2008 with clinical HF was undertaken. The most common cause of HF was dilated cardiomyopathy (58 of 99, 59%). Echocardiographic and serum measurements were collected from admission. Factors independently associated with risk of D/Tx were evaluated by a stepwise multivariate Cox regression model. There were 99 children with 139 hospitalizations. Median age at admission was 3 years (range 0 to 22). Mean systemic ventricular ejection fraction was 23% +/- 11. Risk of D/Tx per hospitalization was 60 of 139 (43%). In multivariate analysis, lymphocytopenia, lower ejection fraction, low serum sodium, and higher serum creatinine were independent predictors of D/Tx. These variables correctly predicted those subjects at risk of D/Tx in 82.1% of cases. Subgroup analysis found that brain natruretic peptide did not improve the model's accuracy markedly. In conclusion, serum measurements (percent lymphocytes, sodium, and creatinine) and echocardiographic assessment routinely obtained at admission are predictive of D/Tx in children hospitalized for HF. Significant lymphocytopenia was predictive of adverse outcomes.