The association of maternal lymphatic markers and critical congenital heart defects in the fetus-A population based case-control study.

The objective ot this study was to investigate whether lymphatic markers measured in women during the second trimester are associated with critical congenital heart defects (CCHDs) in offspring. This is a retrospective cohort study of pregnant women who participated in the California Prenatal Screening Program. CCHD data in the offspring was captured by linking birth certificate data with hospital patient discharge records. Second trimester samples were assayed for vascular endothelial growth factor (VEGF), platelet derived growth factor (PDGF) AA/BB, and PDGF AB. Logistic models were used to evaluate the association between lymphatic biomarkers and CCHD. Models were adjusted for other serum biomarkers and maternal characteristics. Results are presented in odds ratios (OR) with 95% confidence intervals (CI). We identified 93 cases with CCHDs and 194 controls without CCHDs. The crude and adjusted OR for log (ln) VEGF was 1.07 (95%CI 0.94-1.22) and 1.08 (95%CI 0.94-1.24), respectively; for ln PDGF AB/BB was 0.93 (95%CI 0.6-1.35) and 0.58 (95%CI 0.32-1.05), respectively. There was a significant association between ln PDFG AA and CCHDs (crude OR 1.83 (95%CI 1.05-3.2); adjusted OR 2.41 (95%CI 1.06-5.44)). Levels of circulating PDGF AA were highest in cases with hypoplastic left heart syndrome (HLHS) (mean 8.78 +/- 1.54 pg/ml). In this study, increased mid-pregnancy maternal serum levels of PDGF AA were associated with CCHDs in offspring. The highest PDGF AA levels were found in mothers of fetuses with HLHS. These findings may be useful in screening for CCHDs and offer insight into their association with nuchal translucency.

Association of Interstage Home Monitoring With Mortality, Readmissions, and Weight Gain: A Multicenter Study from the National Pediatric Cardiology Quality Improvement Collaborative.

BACKGROUND: Daily home monitoring of oxygen saturation and weight has been reported to improve outcomes for patients with single-ventricle heart disease during the period between stage I palliation and stage II palliation. However, these studies have been limited to single institutions and used historical control subjects. Our objective was to determine the association of various interstage home monitoring strategies with outcomes using a multicenter cohort with contemporary control subjects. METHODS AND RESULTS: We performed a retrospective cohort study using prospectively collected data from the National Pediatric Cardiology Quality Improvement Collaborative from 2008 to 2012. We compared interstage mortality, unscheduled readmissions, and change in weight-for-age Z score for various home monitoring strategies of oxygen saturation (n=494) or weight (n=472), adjusting for sex, syndrome, tricuspid regurgitation, arch obstruction, and shunt type. Overall interstage mortality was 8.1%, and 47% had ≥1 unscheduled readmission. We did not find any associations of home oxygen saturation or weight monitoring with mortality or readmission. Although there was no difference in weight-for-age Z score for daily (0.33±0.12) versus weekly (0.34±0.18, P=0.98) weight monitoring, daily home weight monitoring was superior to no home weight monitoring (-0.15±0.18; P<0.01). CONCLUSIONS: Home weight monitoring is associated with improved weight gain during the interstage period, but we did not find any benefits in other clinical outcomes for either home oxygen saturation monitoring or home weight monitoring.

Serum cortisol and early postoperative outcome after stage-1 palliation for hypoplastic left heart syndrome.

OBJECTIVES: The postoperative cortisol profile and its association with early outcomes are poorly understood in neonates undergoing surgery for complex congenital heart disease. We investigated the postoperative profile of cortisol and its relationship with the clinical course in a cohort of newborns after stage-1 palliation for hypoplastic left heart syndrome. DESIGN: Prospective observational study. SETTING: Pediatric cardiovascular ICU at a tertiary children's hospital. SUBJECTS: Twenty-three neonates after stage-1 palliation for hypoplastic left heart syndrome between 2009 and 2011. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Three serial measurements of total serum cortisol after surgery. The first measurement was taken immediately after surgery and the second and third-on the first and second postoperative mornings. The median weight of the infants was 3.0 kg (2.7-3.4 kg), and the age at surgery was 7 days (6-9 d). The median (25th-75th percentile) cortisol levels at admission, day 1, and day 2 were 96.2 µg/dL (51.1-112 µg/dL), 17.3 µg/dL (9.7-25.1 µg/dL), and 10 µg/dL (6.5-17 µg/dL), respectively (p < 0.0001 between admission and day 1). Higher cortisol was associated with greater morbidity, including the need for preoperative ventilation, increased total duration of ventilation, duration of inotropic support, and hospital length of stay. CONCLUSIONS: Cortisol levels fell significantly over the first 24 hours after stage-1 palliation for hypoplastic left heart syndrome. A higher postoperative cortisol was associated with increased postoperative morbidity, which warrants further investigation.

Impact of mode of delivery on markers of perinatal hemodynamics in infants with hypoplastic left heart syndrome.

OBJECTIVE: To determine whether the mode of delivery of infants prenatally diagnosed with hypoplastic left heart syndrome (HLHS) affects markers of perinatal hemodynamics. STUDY DESIGN: A retrospective review of patients diagnosed prenatally with HLHS and delivered within our institution was undertaken. Arterial blood gases, echocardiographic data, and markers of end organ function were compared based on route of delivery. RESULTS: A total of 79 infants with HLHS were enrolled between January 2002 and December 2008. The infants delivered by elective cesarian delivery (CD) had younger gestational age compared with those delivered by vaginal delivery (VD) or by urgent CD/operative VD. Those delivered by elective CD had lower pH and higher partial pressure of CO(2) on arterial cord blood gas analysis. There were no differences in partial pressure of O(2) and base deficit among the 3 study groups. One-minute and 5-minute Apgar scores, markers of end organ function, echocardiographic parameters, length of hospitalization, and survival to discharge were similar among the groups. CONCLUSIONS: Overall, newborns with a prenatal diagnosis of HLHS transitioned well to extrauterine life without significant acidosis regardless of the mode of delivery. Delivery of newborns with HLHS by elective CD did not demonstrate any hemodynamic advantage over VD in our cohort of patients.

Technical description of the use of selective perfusion techniques during the Norwood procedure for hypoplastic left heart syndrome.

Since the introduction of the Norwood procedure for surgical palliation of hypoplastic left heart syndrome in 1983, refinements have been made to the original procedure to improve patient outcomes while still accomplishing the original goals of the procedure. One of these refinements has been the introduction of regional selective perfusion to limit the duration of circulatory arrest times and optimize the regional flow distribution. In this paper we describe our technique for performing selective cerebral and lower body perfusion during the Norwood procedure.

Altered metabolic and inflammatory transcriptomics after cardiac surgery in neonates with congenital heart disease.

The study examines the whole blood transcriptome profile before and after cardiopulmonary bypass (CPB) in neonates with hypoplastic left heart syndrome (HLHS), a severe form of congenital heart disease, that can develop low cardiac output syndrome (LCOS). Whole blood mRNA transcriptome profiles of 13 neonates with HLHS before and after their first palliative surgery were analyzed to determine differentially expressed genes and pathways. The median age and weight at surgery were 4 days and 3.2 kg, respectively. Of the 13 patients, 8 developed LCOS. There was no significant difference between CPB, aortic cross clamp, deep hypothermic cardiac arrest times between patients that develop LCOS and those that do not. Upon comparing differential gene expression profiles between patients that develop LCOS and those that do not in pre-operative samples, 1 gene was up-regulated and 13 were down regulated. In the post-operative samples, 4 genes were up-regulated, and 4 genes were down regulated when patients that develop LCOS were compared to those that do not. When comparing post-operative samples to pre-operative samples in the patients that do not develop LCOS, 1484 genes were up-regulated, and 1388 genes were down regulated; while patients that developed LCOS had 2423 up-regulated genes, and 2414 down regulated genes for the same pre to post-operative comparison. Pathway analysis revealed differential regulation of inflammatory pathways (IL signaling, PDGF, NOTCH1, NGF, GPCR) and metabolic pathways (heme metabolism, oxidative phosphorylation, protein metabolism including amino acid and derivatives, fatty acid metabolism, TCA cycle and respiratory electron transport chain). By identifying altered transcriptome profiles related to inflammation and metabolism in neonates with HLHS who develop LCOS after CPB, this study opens for exploration novel pathways and potential therapeutic targets to improve outcomes in this high-risk population.

Changes in cerebral oxygen saturation and blood flow during hypoxic gas ventilation therapy in HLHS and CoA/IAA complex with markedly increased pulmonary blood flow.

BACKGROUND: Hypoxic gas ventilation therapy has recently been performed to prevent post-birth increased pulmonary blood flow in cases of congenital heart diseases with increased pulmonary blood flow. However, how the oxygen supply to the tissues changes during breathing a hypoxic gas mixture, remains unknown. The changes in cerebral oxygen saturation and blood supply during hypoxic gas ventilation therapy using a nitrogen gas mixture were studied. METHODS AND RESULTS: Cerebral regional oxygen saturation (cerebral rSO(2)) was measured by near-infrared spectroscopy, and changes in middle cerebral artery (MCA) blood flow and an index of vascular resistance (RI) were assessed in 8 consecutive patients having congenital heart diseases with increased pulmonary blood flow. In all patients, urinary volume increased significantly, and the respiratory rate showed a clear decrease. Percutaneous oxygen saturation showed no significant change. The average of cerebral rSO(2) was 67.3% before hypoxic gas ventilation, but increased to 69.4%, 69.1%, and 70.7% within 1, 12, and 24 h after initiation of treatment, respectively. MCA blood flow significantly increased in the diastolic phase, and RI significantly improved from 0.80 to 0.68 within 12 h after initiation of therapy. CONCLUSIONS: These results indicate that hypoxic gas ventilation therapy does not decrease cerebral oxygen saturation, but safely improves the cerebral blood supply in cases of congenital heart diseases with increased pulmonary blood flow.

Interstage Home Monitoring for Infants With Single Ventricle Heart Disease: Education and Management: A Scientific Statement From the American Heart Association.

This scientific statement summarizes the current state of knowledge related to interstage home monitoring for infants with shunt-dependent single ventricle heart disease. Historically, the interstage period has been defined as the time of discharge from the initial palliative procedure to the time of second stage palliation. High mortality rates during the interstage period led to the implementation of in-home surveillance strategies to detect physiologic changes that may precede hemodynamic decompensation in interstage infants with single ventricle heart disease. Adoption of interstage home monitoring practices has been associated with significantly improved morbidity and mortality. This statement will review in-hospital readiness for discharge, caregiver support and education, healthcare teams and resources, surveillance strategies and practices, national quality improvement efforts, interstage outcomes, and future areas for research. The statement is directed toward pediatric cardiologists, primary care providers, subspecialists, advanced practice providers, nurses, and those caring for infants undergoing staged surgical palliation for single ventricle heart disease.

Neutrophil-lymphocyte ratio as a mortality predictor for Norwood stage I operations.

BACKGROUND: Hypoplastic left heart syndrome is a lethal congenital heart malformation when untreated resulting in a 95% mortality in the first month of life. In this study, we aimed to investigate the newly introduced inflammatory biomarker, neutrophil-lymphocyte ratio, as a mortality predictor in postoperative hypoplastic left heart syndrome patients. METHODS: Patients were divided into two groups; Group 1 consisted of 33 patients who were discharged and Group 2 including 20 patients who were deceased following surgery. Patients' preoperative demographic characteristics, total white blood cell counts, neutrophil counts, lymphocyte counts, neutrophil-lymphocyte ratio, C-reactive proteins, alanine aminotransferase, aspartate transaminase, urea, and creatinine levels were recorded. Studys' primary endpoint was all-cause patient mortality following surgery. RESULTS: The preoperative neutrophil-lymphocyte ratio was found to be significantly different between the groups (p = 0.001). High neutrophil-lymphocyte ratio was found to be associated with an increased risk of death. The ROC curves of neutrophil-lymphocyte ratio were found to be associated with mortality. The area under curve for the preoperative neutrophil-lymphocyte ratio was 0.74. Neutrophil-lymphocyte ratio predicted mortality with a sensitivity of 78% and a specificity of 65%. CONCLUSION: Neutrophil-lymphocyte ratio can contribute to the early identification of patients at high risk for complications. In addition, through the use of NLR, clinicians could implement measures for the optimal therapeutic approach of cardiac surgery patients and the elimination of adverse patient outcomes.

Optimal pulmonary to systemic blood flow ratio for best hemodynamic status and outcome early after Norwood operation.

OBJECTIVE: Imbalances of pulmonary to systemic blood flow ratio (Q(p)/Q(s)) compounded with inadequate systemic oxygen delivery correlate with mortality after first-stage Norwood palliation of hypoplastic left heart syndrome. Mathematical models suggest that maximal systemic oxygen delivery occurs with Q(p)/Q(s) of less than 1. Whether this applies to clinical practice is unclear. This study evaluates the level of Q(p)/Q(s) that correlates with best hemodynamic status in the first 48 postoperative hours. METHODS: Hemodynamic data of 25 consecutive patients who underwent Norwood procedure from October 2002 to January 2005 were retrospectively analyzed. Data included, in particular, systemic venous and arterial oxygen saturation (SvO(2) and SaO(2), respectively), Q(p)/Q(s), lactate levels, and doses of required inotropes. Parameters were recorded 3 hourly. Data were assigned to three groups according to their corresponding Q(p)/Q(s): Groups 1, 2, and 3 for Q(p)/Q(s)< or =1, Q(p)/Q(s) between 1 and 2, and Q(p)/Q(s)> or =2, respectively. Thereafter, independent t-test or Fisher's exact test was used to reveal significant differences. Q(p)/Q(s) ratios and lactate levels were compared in hospital survivors and non-survivors. RESULTS: Out of 343 samples, 110, 184, and 49 were assigned to groups 1, 2, and 3, respectively. Group 1 (Q(p)/Q(s)< or =1) was characterized by lower SaO(2) (p<0.001) with similar SvO(2) (p=0.3 and p=0.5) and, therefore, higher systemic oxygen delivery (arteriovenous oxygen saturation difference, p<0.001; oxygen excess factor, p<0.001) compared to groups 2 and 3. However, lower mean arterial pressure (p=0.07 and p<0.001), higher lactate levels (p=0.009 and p=0.01), and norepinephrine doses (p=0.006 and p<0.001) highlighted worse hemodynamics. The best hemodynamic status corresponded to group 2. Q(p)/Q(s) remained above 1 in 21 survivors and was, most of the times, below 1 in four patients who died. Lactate levels were almost always above 4 mmol/l or increasing in non-survivors. CONCLUSIONS: Maximum oxygen delivery after Norwood operation occurs at Q(p)/Q(s) of less than 1. However, optimal hemodynamic status and end-organ function and higher survival correlates with Q(p)/Q(s) between 1 and 2. Thus, Q(p)/Q(s) should be targeted at 1.5 for improved course early after first-stage Norwood palliation.

Population pharmacokinetics of milrinone in neonates with hypoplastic left heart syndrome undergoing stage I reconstruction.

We performed a blinded, randomized pharmacokinetic study of milrinone in 16 neonates with hypoplastic left heart undergoing stage I reconstruction to determine the impact of cardiopulmonary bypass and modified ultrafiltration on drug disposition and to define the drug exposure during a continuous IV infusion of drug postoperatively. Neonates received an initial dose of either a 100 or 250 microg/kg of milrinone into the cardiopulmonary bypass circuit at the start of rewarming. Postoperatively, milrinone was infused to clinical needs. A mixed-effect modeling approach was used to characterize milrinone pharmacokinetics during cardiopulmonary bypass, modified ultrafiltration, and postoperatively using the NONMEM algorithm. All patients in this study demonstrated a modified ultrafiltration concentrating effect that occurred despite a modified ultrafiltration drug clearance of 3.3 mL x kg(-1) x min(-1). The infants in this study demonstrated an impaired renal clearance during the immediate postoperative period. A constant infusion of 0.5 microg x kg(-1) x min(-1) resulted in drug accumulation during the initial 12 h of drug administration. Postoperatively, milrinone clearance was significantly impaired (0.4 mL x kg(-1) x min(-1)), improved by the 12th postoperative hour, and approached steady-state clearance (2.6 mL x kg(-1) x min(-1)) by postoperative day 4. In the postoperative setting of markedly impaired renal function, an infusion rate of 0.2 microg x kg(-1) x min(-1) should be considered.

Cardiopulmonary Bypass Increases Plasma Glial Fibrillary Acidic Protein Only in First Stage Palliation of Hypoplastic Left Heart Syndrome.

BACKGROUND: Univentricular congenital heart defects require open-heart surgery soon after birth, and are associated with risk of brain injury and poor neurologic outcome. METHODS: This is a prospective, observational study on children undergoing cardiac surgery. Plasma glial fibrillary acidic protein (GFAP), as an early marker of brain injury, was measured by ELISA at the end of anaesthesia induction, initiation of cardiopulmonary bypass (CPB), the end of cooling, the end of rewarming, the end of CPB, and after protamine administration. We recorded clinical and surgical parameters to assess which CPB phase and clinical parameters were associated with a GFAP increase. RESULTS: We studied 13 children less than 50 months of age: 8 underwent Norwood or Damus-Kaye-Stansel palliation (group 1) and 5 underwent Fontan procedure (group 2). A GFAP increase was only observed in group 1, with the highest median value at the end of rewarming. No quantifiable levels of GFAP were measured at pre-bypass and the start of CPB stages in all patients. End of cooling and CPB-end GFAP, GFAP maximum value, and GFAP area under the curve all correlated with the CPB time spent at a cerebral regional saturation < 45% (P = 0.021, 0.028, 0.007, 0.021, respectively). CONCLUSIONS: Children with univentricular heart defects exhibit a CPB plasma-GFAP increase only after stage 1 palliation. The maximum GFAP increase occurred at the end of rewarming. Further studies are needed to identify which clinical or surgical parameter(s) could reflect a GFAP increase during surgery for congenital heart defects, and whether GFAP levels correlate with the neurologic outcome.

Ventricular fibrogenesis activity assessed by serum levels of procollagen type III N-terminal amino peptide during the staged Fontan procedure.

OBJECTIVE: We tested the hypotheses that volume overload and cyanosis observed in the pre-Fontan single ventricular circulation are associated with increased ventricular fibrogenesis, that the Fontan procedure helps to reduce fibrogenesis, and that persistently increased fibrogenesis in the Fontan ventricle is associated with ventricular diastolic dysfunction. METHODS: Levels of serum amino-terminal procollagen type III, a marker of tissue fibrogenesis, were measured in 172 patients with single ventricle circulation and 149 controls. Patients were divided into 3 groups according to surgical stage: 59 patients after Blalock-Taussig shunt or pulmonary banding, 60 patients after Glenn surgery (Glenn group), and 53 patients after Fontan surgery (Fontan group). RESULTS: Serum amino-terminal procollagen type III levels were significantly higher among the 3 single ventricle groups than among control patients, but decreased with each surgical stage (0.604, 0.176, 0.143, and 0.073 U/mL, for Blalock-Taussig shunt or pulmonary banding, Glenn, Fontan, and controls, respectively). Severity of volume load and cyanosis were independent determinants of increased amino-terminal procollagen type III levels in patients before Fontan surgery, and persistently increased amino-terminal procollagen type III after Fontan surgery was associated with ventricular diastolic stiffening (r = 0.494, P = .009). Data also indicated close associations between amino-terminal procollagen type III levels and activation of the renin-angiotensin-aldosterone system, suggesting potential involvement of this hormonal system in the increased fibrogenesis after Fontan surgery. CONCLUSIONS: These results suggest that serum amino-terminal procollagen type III may provide important diagnostic information on myocardial fibrosis in patients with single ventricle circulation and raise the possibility that ventricular fibrogenesis may be a potential therapeutic target in this population.

Balancing the circulation: theoretic optimization of pulmonary/systemic flow ratio in hypoplastic left heart syndrome.

OBJECTIVES: This study examined the effects of the pulmonary (QP)/systemic (QS) blood flow ratio (QP/QS) on systemic oxygen availability in neonates with hypoplastic left heart syndrome. BACKGROUND: The management of neonates with hypoplastic left heart syndrome is complex and controversial. Both before and after surgical palliation and before heart transplantation, a univentricle with parallel pulmonary and systemic circulations exists. It is generally assumed that balancing pulmonary and systemic blood flow is best to stabilize the circulation. METHODS: We developed a mathematical model that was based on the simple flow of oxygen uptake in the lungs and whole-body oxygen consumption to study the effect of varying the QP/QS ratio. An equation was derived that related the key variables of cardiac output, pulmonary venous oxygen saturation and the QP/QS ratio to systemic oxygen availability. RESULTS: The key findings are 1) as the QP/QS ratio increases, systemic oxygen availability increases initially, reaches a maximum and then decreases; 2) for maximal systemic oxygen availability, the optimal QP/QS ratio is < or = 1; 3) the optimal QP/QS ratio decreases as cardiac output or percent pulmonary venous oxygen saturation, or both, increase; 4) the critical range of QP/QS, where oxygen supply exceeds basal oxygen consumption, decreases as cardiac output and percent pulmonary venous oxygen saturation decrease; 5) the relation between oxygen availability and QP/QS is very steep when QP/QS approaches this critical value; and 6) the percent oxygen saturation of systemic venous blood is very low outside the critical range of QP/QS and high within the critical range. CONCLUSIONS: This analysis provides a theoretic basis for balancing both the pulmonary and systemic circulation and suggests that evaluating both systemic arterial and venous oxygen saturation may be a useful way to determine the relative pulmonary and systemic flows. When high systemic arterial and low systemic venous oxygen saturation are present, pulmonary blood flow should be decreased; conversely, when both low systemic arterial and venous oxygen saturation are present, more flow should be directed to the pulmonary circulation.

Right ventricle-to-pulmonary artery shunt and modified Blalock-Taussig shunt in preparation to hemi-Fontan procedure in children with hypoplastic left heart syndrome.

OBJECTIVE: The advantageous effect of right ventricle-to-pulmonary artery shunt (RV-PA) on the early postoperative hemodynamics in the Norwood procedure for hypoplastic left heart syndrome (HLHS) is well known. Numerous controversies still exist with respect to the late consequences of this new palliation method in preparation for the second stage procedure. METHODS: Between September 1997 and September 2004, a consecutive series of 78 children with HLHS from a single institution underwent the hemi-Fontan procedure: Group 1 (n=27) after Blalock-Taussig shunt (BT), and Group 2 (n=51) after RV-PA. Hemodynamic, echocardiographic and clinical perioperative data were analyzed. RESULTS: There were no significant differences in the age and operative weight (Group 1: 6.9+/-1.04 months, 6.22+/-0.99 kg; Group 2: 6.57+/-1.12 months, 6.36+/-0.86 kg). Children after RV-PA were characterized by a significantly higher preoperative hematocrit value (P=0.014), lower aortic and superior vena cava oxygen blood saturation (P<0.001, P=0.024), severe right ventricle hypertrophy more rarely diagnosed in echocardiography (P<0.004), lower Qp:Qs ratio (P=0.011), larger right (P=0.001) and left (P=0.006) pulmonary artery index and a shorter intensive care unit stay after the hemi-Fontan procedure (P=0.004). CONCLUSIONS: The Norwood procedure with the RV-PA shunt provides satisfactory late hemodynamics and improves the development of the pulmonary arteries. Children with hypoplastic left heart syndrome subjected to this new method of palliation are good candidates for the hemi-Fontan procedure.

Restrictive left atrial outflow adversely affects outcome after the modified Norwood procedure.

OBJECTIVE: Moderate restrictive foramen ovale in neonates with hypoplastic left heart syndrome (HLHS) is considered to be favourable, reducing pulmonary overcirculation, before modified Norwood operation. However, some newborns with severe restriction of interatrial communication will have pulmonary vascular disease at birth, which correlates with increased perioperative mortality. This article studies the post-Norwood hemodynamic patterns and outcome for the particular group of HLHS newborns with restrictive left atrial outflow compared to other patients. METHODS: Restrictive left atrial outflow is defined as mitral and/or aortic atresia with intact ventricular septum, and restrictive foramen ovale, with 3 mm diameter or less with mean interatrial pressure gradient more than 5 mmHg at preoperative echo-Doppler. Four neonates fulfilled these criteriae among 18 consecutive patients, who underwent Norwood procedure from October 2002 to December 2003. Mean arterial pressure, heart rate, mean common atrial pressure, urinary output, central venous and arterial oximetry data, serum lactate levels, and dosages of milrinone, phentolamine and norepinephrine were collected at 0, 6, 12, 18 and 24 h after operation. Data were summarized as mean+/-SEM. For univariate comparison of different variables, Student's t-test was used. RESULTS: The postoperative hemodynamic pattern of patients with restrictive left atrial outflow was characterized by hypoxemia and low cardiac output. Arterial (66+/-3.0% vs 76+/-1.0%, P=0.01) and central venous (37+/-1.2 vs 52+/-1.1%, P=0.001) oxygen saturations were much lower than in patients without restriction. Arterio-venous oxygen saturation difference was wider (29+/-2.4% vs 23+/-0.9%, P=0.02) and serum lactate levels were higher (10.8+/-3.0 vs 2.8+/-0.2 mmol/l, P=0.03). Common atrial pressures were more elevated (12+/-0.8 vs 8+/-0.3 mmHg, P<0.001) and higher norepinephrine doses were needed (0.44+/-0.15 vs 0.06+/-0.01 microg/kg/min, P=0.03). The difference for the mean arterial pressures did not reach the significance level (48+/-2.0 vs 51+/-2.0 mmHg, P=0.2). Operative mortality was higher 75% (3/4) compared to 14.3% (2/14, P=0.04) for the other patients. CONCLUSIONS: Restrictive left atrial outflow adversely affects outcome after modified Norwood procedure. Abnormal pulmonary vasculature leading to insufficient pulmonary perfusion is incriminated. To improve outcome, implantation of larger size modified Blalock-Taussig or right ventricle-to-pulmonary artery shunts and routine use of postoperative mechanical assist device should be considered.

Umbilical neutrophil gelatinase-associated lipocalin level as an early predictor of acute kidney injury in neonates with hypoplastic left heart syndrome.

Acute kidney injury (AKI) is a primarily described complication after unbalanced systemic perfusion in neonates with congenital heart defects, including hypoplastic left heart syndrome (HLHS). The aim of the study was to compare the umbilical NGAL concentrations between neonates born with HLHS and healthy infants, as well as to analyze whether the determination of NGAL level could predict AKI in neonates with prenatally diagnosed HLHS. Twenty-one neonates with prenatally diagnosed HLHS were enrolled as study group and 30 healthy neonates served as controls. Perinatal characteristics and postnatal parameters were extracted from the hospital neonatal database. In umbilical cord blood, we determined plasma NGAL concentrations, acid base balance, and lactate and creatinine levels. In neonates with HLHS, complications (respiratory insufficiency, circulatory failure, NEC, IVH, and AKI) were recorded until the day of cardiosurgery. We observed in neonates with HLHS higher umbilical NGAL levels compared to controls. Among 8 neonates with HLHS and diagnosed AKI stage 1, we observed elevated NGAL levels in comparison to those newborns without AKI. Umbilical NGAL could predict, with high sensitivity and specificity, AKI development in study neonates. We suggest that the umbilical blood NGAL concentration may be an early marker to predict AKI in neonates with HLHS.

The pharmacokinetics of injectable allopurinol in newborns with the hypoplastic left heart syndrome.

OBJECTIVE: The purpose of this investigation was to determine the pharmacokinetic disposition of intravenous allopurinol and its metabolite oxypurinol in neonates with the hypoplastic left heart syndrome (HLHS) and to evaluate the subsequent degree of xanthine oxidase inhibition using serum uric acid as a marker. METHODS: Pharmacokinetic data were evaluated in 12 stable preoperative neonates with HLHS after a single intravenous allopurinol administration of 5 mg/kg or 10 mg/kg. Pharmacokinetic parameters were determined for elimination half-life, clearance, volume of distribution, and mean residence time. Xanthine oxidase inhibition, measured by serum uric acid reduction, was also measured. RESULTS: Pharmacokinetic parameters revealed no statistically significant differences between a 5-mg/kg and 10-mg/kg dose of intravenous allopurinol on elimination half-life, clearance, volume of distribution, and mean residence time. Mean serum uric acid levels were significantly reduced from baseline by 39.99 and 42.94%, respectively, in the 5- and 10-mg/kg treatment groups. DISCUSSION: The enzyme xanthine oxidase plays a key biochemical role in the generation of toxic oxygen-derived free radicals during ischemia-reperfusion conditions. Allopurinol and its active metabolite oxypurinol inhibit xanthine oxidase, and significantly reduce the conversion of hypoxanthine to xanthine and xanthine to uric acid. Cell injury may be caused by toxic oxygen free radicals produced by ischemia-reperfusion injury such as could occur during the repair of HLHS under hypothermic total circulatory arrest. We hypothesize that allopurinol may provide protection from cellular injury in this clinical context.