Comparison of Two Techniques of Superior Vena Cava Flow Measurement in Preterm Infants With Birth Weight <1,250 g in the Transitional Period-Prospective Observational Cohort Study.

Objectives: Superior Vena Cava (SVC) flow in neonates measured by the standard approach has been validated by different groups around the world. The modified SVC flow measurement technique was recently suggested. The aim of our study was to evaluate standard and modified technique of echocardiography SVC flow measurement in a cohort of extremely preterm neonates in the immediate postnatal period. Methods: Prospective, observational cohort study in a level III neonatal center. Infants with birth weight <1,250 g were eligible for enrolment. SVC flow was measured by echocardiography using standard and modified methods at 6, 18 and 36 h of age. Our primary outcome was equivalency (using raw bounds of -20 to +20 mL/kg/min difference between the paired measurements), agreement and correlation between standard and modified methods of the SVC flow measurements. Results: Thirty-nine infants were enrolled. The mean gestational age of the cohort was 27.4 (SD 2.1) weeks of postmenstrual age, the mean birth weight was 0.95 kg (SD 0.2). The measurements at 6 and 36 h of age were equivalent as defined in the design of the study (p = 0.003 and p = 0.004 respectively; raw bounds -20 to +20 mL/kg/min). At 6 h of age the mean difference (bias) between the measurements was -0.8 mL/kg/min with 95% limits of agreement -65.0 to 63.4 mL/kg/min. At 18 h of age, the mean difference (bias) between the measurements was +9.5 mL/kg/min, with 95% limits of agreement -79.6 to 98.7 mL/kg/min. At 36 h of age the mean difference (bias) between the measurements was -2.2 mL/kg/min with 95% limits of agreement -73.4 to 69.1 mL/kg/min. There was a weak, but statistically significant correlation between the standard and modified method at 6 h of age (r = 0.39, p = 0.04). Conclusion: Both SVC flow echocardiography measurement techniques yielded clinically equivalent results, however due to wide limits of agreement and poor correlation they do not seem to be interchangeable.

Low cardiac output measured by bioreactance and adverse outcome in preterm infants with birth weight less than 1250 g.

BACKGROUND: Recently a new continuous non-invasive cardiac output measurement, bioreactance, has become available. Bioreactance measurement of cardiac output has been shown to correlate with left ventricular output detected by echocardiography in healthy term and preterm neonates. AIMS: Our aim was to correlate cardiac output measurements by bioreactance in the first 48 h of life with adverse outcomes attributable to hypoperfusion (peri/intraventricular haemorrhage (PIVH) and/or necrotising enterocolitis (NEC)) in the cohort of extremely preterm infants. STUDY DESIGN: A prospective observational cohort study. SUBJECTS: Preterm infants with birth weight less than 1250 g. OUTCOME MEASURES: Cardiac output was measured between six and 48 h of age by bioreactance. Our primary outcome was a difference in cardiac output between infants with an adverse outcome attributable to hypoperfusion (Group 1), and infants without the predefined adverse outcome (Group 2). RESULTS: There were 39 infants enrolled in the study. There were six infants in Group 1. These infants had a significantly lower minimal cardiac output measurement compared to Group 2 (mean 36.7 ml/kg/min vs 64.5 ml/kg/min, p = .0006). The mean cardiac output in Group 1 was significantly lower on day one of life, followed by a significant increase in cardiac output on day two of life compared to Group 2. CONCLUSIONS: Infants with birth weight less than 1250 g and PIVH and/or NEC had significantly lower cardiac output compared to infants without these complications on day one of life. This low cardiac output was then followed by a significant increase on day two of life.

Are antibiotics a risk factor for the development of necrotizing enterocolitis-case-control retrospective study.

Previous studies have identified numerous risk factors associated with necrotizing enterocolitis (NEC) in very low birth weight (VLBW; birth weight less than 1500 g) infants. One of the potential pathophysiological contributors could be antibiotic therapy. Our aim was to explore the association between antibiotic exposure and NEC in VLBW infants. We designed a retrospective 1:2 case-control cohort study in a level III neonatal intensive care unit. Our study group composed of VLBW infants born between January 2012 and December 2014 with a diagnosis of NEC stage IIA or greater (Bell's modified criteria). Our intent was to match every case in the study group to two controls. Our primary outcome was an association between antibiotic exposure and NEC. Twenty-two cases of NEC were matched to 32 controls. The infants who developed NEC were exposed to a statistically significantly more frequent number of antibiotic courses and to more days on any antibiotic prior to the development of NEC. There were significant differences between cases and controls with respect to the duration of exposure to gentamicin and meropenem specifically.Conclusion: The data from our study demonstrate that prolonged exposure to antibiotic therapy is associated with an increased risk of NEC among VLBW infants. Furthermore, gentamicin and meropenem, but not other antibiotics, had a significant association with the incidence of NEC. What is known: • Early antibiotic exposure is a risk factor for the development of necrotising enterocolitis (NEC) in very low birth weight infants • Prolonged initial empirical antibiotic course for ≥ 5 days, despite sterile blood culture, is associated with an increased risk of developing NEC What is new: • The cumulative total number of days of antibiotic exposure is associated with an increased risk of developing NEC • Gentamicin and meropenem, but not other antibiotics, had a significant association with the incidence of NEC in our study.

Effect of Early Parenteral Nutrition Discontinuation on Time to Regain Birth Weight in Very Low Birth Weight Infants: A Randomized Controlled Trial.

BACKGROUND: Peripherally inserted central catheters (PICCs) are used to administer parenteral nutrition (PN) in very low birth weight infants (VLBW; <1500 g). Clinicians try to optimize early nutrition but also minimize the risks associated with intravascular devices. The objective of this study was to examine the early nutrition impact of discontinuing PN at different enteral feed volumes in VLBW infants. METHODS: In this unmasked, multicenter, randomized controlled trial, patients were randomly assigned to PICC removal and PN discontinuation at an enteral feed volume of 100 mL/kg/day (intervention) or 140 mL/kg/day (control). Clinically stable VLBW infants with a PICC in situ who were receiving PN were eligible for inclusion. Infants with major congenital anomalies were excluded. A total of 139 patients were enrolled; 69 and 70 patients were randomized to the intervention and control groups, respectively. The primary outcome measure was the mean difference in time (days) to regain birth weight. RESULTS: The groups were well matched at study entry. Patients in the intervention group regained birth weight more slowly (mean difference 1.5 days CI: 0.3-2.7 days, P = 0.01). The mean difference in time to regain birth weight for infants <1000 g was 2.8 days (95% CI: 0.8-4.8 days, P = 0.008). CONCLUSIONS: In VLBW infants, early PICC removal at an enteral feed volume of 100 mL/kg/day compared with later removal at 140 mL/kg/day resulted in a significant delay in time to regain birth weight, and this delay was more pronounced in infants <1000 g.

Immune Abnormalities in Patients With Single Ventricle Circulation Precede the Fontan Procedure.

BACKGROUND: Immune abnormalities are common in Fontan patients with protein-losing enteropathy. Limited data exist on immune function of other patients with single ventricle circulation. METHODS: This prospective cohort study evaluated immunologic characteristics of children with single ventricle circulation from neonatal age up to early post-Fontan period. RESULTS: Low leukocyte counts were observed in half of the patients prior to bidirectional Glenn and Fontan surgery. Total lymphocyte counts were below normal range in 36% to 63% of patients across all groups except patients following Fontan procedure who had normal counts. Typical lymphocyte subpopulation patterns were (1) high counts of total and helper T lymphocytes (CD3+ and CD4+ cells), low B lymphocytes (CD19+ cells), and increased CD4/CD8 ratio in neonates and (2) low T lymphocytes (CD3+, CD4+, CD8+ cells) with high natural killer cells (CD16+) and B lymphocytes (CD19+ cells) in other groups. Low preoperative total lymphocyte counts were associated with longer intensive care unit stay in patients after bidirectional Glenn and Fontan procedure ( P = .03 and P = .01, respectively) and low leukocyte counts with higher incidence of pleural effusions and chylothorax after Fontan procedure ( P = .005 and P = .002, respectively). CONCLUSIONS: Single ventricle patients display several immunological abnormalities. Beyond the neonatal age, an immune pattern includes CD3+, CD4+, CD8+ lymphopenia, and CD16+ and CD19+ lymphocytosis. B-cell lymphocytosis compensates T-cell lymphopenia, producing normal total lymphocyte counts in patients early after Fontan surgery. Low preoperative total lymphocyte counts may be associated with longer postoperative intensive care unit stay in patients with bidirectional Glenn and Fontan procedure and leukopenia with pleural effusions in Fontan patients.

Noninvasive continuous cardiac output and cerebral perfusion monitoring in term infants with neonatal encephalopathy: assessment of feasibility and reliability.

BackgroundNoninvasive hemodynamic monitoring of infants with neonatal encephalopathy (NE) undergoing therapeutic hypothermia (TH) would be a potentially useful clinical tool. We aimed to assess the feasibility and reliability of noninvasive cardiac output monitoring (NICOM) and near-infrared spectroscopy (NIRS) in this cohort.MethodsNICOM and NIRS were commenced to measure cardiac output (CO), systemic vascular resistance (SVR), blood pressure (BP), and cerebral regional oxygen saturations (SctO2) during TH and rewarming. NICOM measures of CO were also compared with simultaneous echocardiography-derived CO (echo-CO).ResultsTwenty infants with a median gestation of 40 weeks were enrolled. There was a strong correlation between NICOM- and echo-CO (r2=0.79, P<0.001). NICOM-CO was systematically lower than echo-CO with a bias of 27% (limits of agreement 3-51%). NICOM illustrated lower CO during TH, which increased during rewarming. SctO2 increased over the first 30 h of TH and stayed high for the remainder of the study. There was a rise in SVR over the first 30 h of TH and a decrease during rewarming (all P<0.05).ConclusionsNoninvasive hemodynamic assessment of infants with NE is feasible and illustrates potentially important changes. Larger studies are needed to assess the clinical applicability of those methods in this cohort.

Spontaneous Closure of Patent Ductus Arteriosus in Infants ≤1500 g.

OBJECTIVES: Patent ductus arteriosus (PDA) remains a challenging issue in very low birth weight (VLBW) infants, and its management varies widely. Our aim in this study was to document the natural course of ductus arteriosus in a cohort of VLBW infants who underwent conservative PDA management with no medical or surgical intervention. METHODS: A retrospective cohort study conducted in 2 European level-3 neonatal units. RESULTS: A total of 368 VLBW infants were born within the study period. Two hundred and ninety-seven infants were free of congenital malformations or heart defects and survived to hospital discharge. Out of those, 280 infants received truly conservative PDA management. In 237 (85%) of nontreated infants, the PDA closed before hospital discharge. The Kaplan-Meier model was used to document the incidence proportion of PDA closure over time for different gestational age groups. The median time to ductal closure was 71, 13, 8, and 6 days in <26+0, 26+0 to 27+6, 28+0 to 29+6, and ≥30 weeks, respectively. For different birth weight groups, the median was 48, 22, 9, and 8 days in infants weighing <750, 750 to 999, 1000 to 1249, and 1250 to 1500 g, respectively. No statistically significant relationship was found between PDA closure before hospital discharge and neonatal morbidities. CONCLUSIONS: The likelihood of PDA spontaneous closure in VLBW infants is extremely high. We provide in our findings a platform for future placebo-controlled trials focused on the smallest and youngest infants.

High flow nasal cannula versus NCPAP, duration to full oral feeds in preterm infants: a randomised controlled trial.

OBJECTIVE: To compare the time taken by preterm infants with evolving chronic lung disease to achieve full oral feeding when supported with humidified high flow nasal cannula (HFNC) or nasal continuous positive airway pressure (NCPAP). DESIGN: Single centre randomised controlled trial. SETTING: Level III neonatal intensive care unit at the Coombe Women and Infants University Hospital, Dublin, Ireland. PATIENTS: Very low birthweight (birth weight <1500 g) infants born before 30 weeks' gestation who were NCPAP-dependent at 32 weeks corrected gestational age were eligible to participate. INTERVENTIONS: Enrolled infants were randomised in a 1:1 ratio to receive HFNC or NCPAP. Participants were monitored daily until full oral feeding was established and the baby was off respiratory support. MAIN OUTCOME MEASURES: Our primary outcome was the number of days taken to establish full oral feeds (defined as oral intake ≥120 mL/kg/day) from the time of randomisation. We estimated that enrolling 44 subjects (22 in each group) would allow us demonstrate a 7-day difference in our primary outcome with 80% power and α of 5%. RESULTS: Forty-four infants were randomised (22 to HFNC vs 22 to NCPAP). The mean time to achieve full oral feeding was not different between the groups (HFNC 36.5 (±18.2) days vs NCPAP 34.1 (±11.2) days, p=0.61). CONCLUSIONS: Preterm infants treated with HFNC did not achieve full oral feeding more quickly than infants treated with NCPAP. TRIAL REGISTRATION NUMBER: ISRCTN66716753.

Is routine transvaginal cervical length measurement cost-effective in a population where the risk of spontaneous preterm birth is low?

INTRODUCTION: A recent meta-analysis has suggested that routine measurement of the cervical length should be performed in conjunction with the anomaly scan to identify a group of women at increased risk of preterm delivery. We decided to investigate whether this recommendation is justifiable in a population where the risk of preterm birth is low. MATERIAL AND METHODS: We reviewed 12 years of obstetric data from the Coombe Women and Infants University Hospital. Relative risks of adverse outcomes from the randomized controlled trial were applied and we extrapolated the possible numbers of women requiring intervention. We then used published neonatal data to estimate the cost of neonatal care and estimated the costs of providing the service. RESULTS: Over 12 years from 2000 until 2011, there were 94 646 singleton deliveries, 1776 happening before 34 weeks. Spontaneous onset occurred in 882 (49.7%) of this group. These 882 births were studied. If we apply the figures from a randomized controlled trial, 1609 women (1.7% from our total population) would be expected to have a cervical length 15 mm. If we gave vaginal progesterone to all women with a sonographically short cervix, we would reduce the delivery rate before 34 weeks by 27.7%. The annual costs of providing the service were estimated to be €109 249 and the cost of immediate neonatal care was estimated to be €380 514. CONCLUSION: Given the implications associated with preterm delivery, routine measurement of cervical length at the time of the anomaly scan may be justifiable from a cost point of view in a population where the risk of preterm birth is low.

Fatal Primary Capillary Leak Syndrome in a Late Preterm Newborn.

Primary capillary leak syndrome is a rare disease of unknown etiology, characterized by episodes of vascular collapse and plasma extravasation, which may lead to multiple organ failure. Primary capillary leak is extremely rare in children. The authors report a case of a late preterm newborn with fatal capillary leak syndrome of unknown etiology, manifesting as hypotension unresponsive to treatment, extravasation leading to generalised edema, disseminated intravascular coagulation and finally, multiple organ dysfunction syndrome. Aggressive volumotherapy and a combination of inotropes and high doses of terlipressin did not influence systemic vascular collapse and plasma extravasation. The newborn developed multiple organ failure and died on day 27 of life. Investigations performed failed to reveal any specific cause of capillary leak. This is the first report of a fatal primary capillary leak syndrome in a newborn.

Late medical therapy of patent ductus arteriosus using intravenous paracetamol.

OBJECTIVE: To investigate the effect of late treatment with intravenous paracetamol on patent ductus arteriosus (PDA) closure prior to possible PDA ligation. METHODS: A retrospective review of infants with a haemodynamically significant PDA, considered for PDA ligation and treated with intravenous paracetamol prior to possible ligation. RESULTS: Thirty six infants with a median gestation of 26.1 weeks received paracetamol at a median age of 27 days. Paracetamol was associated with immediate closure in nine (25%) infants. There was no response to paracetamol treatment in four (11%) infants who subsequently underwent a PDA ligation. In 23 (64%) infants, the PDA constricted and all but one of this group demonstrated complete PDA closure prior to discharge. CONCLUSIONS: There may be a role for intravenous paracetamol in late closure of infants with a significant PDA to avoid ligation. The use of paracetamol for late treatment of PDA should be systematically evaluated.

Evaluation of lipid and glucose metabolism and cortisol and thyroid hormone levels in obese appropriate for gestational age (AGA) born and non-obese small for gestational age (SGA) born prepubertal Slovak children.

AIM: Obesity is the major determinant of metabolic syndrome. Being born small for gestational age (SGA) may be co-responsible. We aimed at evaluating the association between 1. obesity and 2. being born SGA and the presence of endocrine-metabolic abnormalities in prepubertal Slovak children. METHODS: The study included 98 children, aged 3-10.9 years: 36 AGA-born obese children (OB), 31 SGA-born children (SGA) and 31 appropriate for gestational age born non-obese children (AGA). Fasting serum levels of glucose, total cholesterol, LDL, HDL, triglycerides, fT4, TSH, cortisol and insulin were determined. HOMA-IR was calculated. Personal data about birth weight and length and family history were collected. Actual anthropometric measurement was done. RESULTS: In every group, high prevalence of positive family history of metabolic disorder was found. In comparison with AGA children, OB children were taller (p<0.01) with higher body mass index (BMI) (p<0.001), and had increased insulin levels and homeostasis model assessment for insulin resistance (HOMA-IR) (p<0.001), decreased high-density lipoprotein (HDL) (p<0.001), and a trend to higher cortisol levels (p=0.069) was noted. SGA-born children were shorter (p<0.001), with BMI comparable to the AGA group. They had higher glucose levels (p<0.001), a trend to decreased HDL levels (p=0.085) and increased fT4 levels (p<0.001). A three-fold higher occurrence of metabolic abnormalities was present in obese children and twice more metabolic abnormalities were present in SGA-born children in comparison with AGA-born children. CONCLUSIONS: SGA-born children are more prone to developing endocrine-metabolic abnormalities than non-obese children born AGA, but they are at less risk than obese AGA-born children. We should provide specialized care for obese children already in prepubertal age and pay attention to SGA-born children.

International survey on diagnosis and management of hypotension in extremely preterm babies.

UNLABELLED: Hypotension is a commonly diagnosed and treated complication of extremely low gestational age newborns (ELGAN), but enormous variation in diagnosis, management and clinical practice has been documented. We sought to evaluate practice regarding the management of hypotension in ELGANs and developed a web-based questionnaire addressing diagnosis, intervention thresholds and modes of treatment of hypotension in ELGANs. We received 216 completed questionnaires from respondents in 38 countries. Most responses (83 %) were from specialist units where, together, over 26,000 very low birth weight (VLBW) infants are cared for annually. The majority (73 %) defined hypotension as a mean blood pressure (BP) in mmHg less than the gestational age in weeks. Sixty percent assessed the circulation with additional methods; echocardiography was the most commonly used (74 %), with left ventricular output and fractional shortening the two most common measurements made. The majority (85 %) used volume administration as the initial intervention. Dopamine was the inotrope most commonly used initially (80 %). If the initial inotrope therapy failed, dobutamine was the most popular second-line treatment (28 %). Delayed cord clamping was used at 51 % of the centres. CONCLUSION: The definition of hypotension in ELGANs continues to follow traditional standards. Functional echocardiography is now used to assess the circulation at many centres. Volume expansion and dopamine remain the most frequently used therapies.

Nanoparticle size and surface charge determine effects of PAMAM dendrimers on human platelets in vitro.

Blood platelets are essential in maintaining hemostasis. Various materials can activate platelets and cause them to aggregate. Platelet aggregation in vitro is often used as a marker for materials' thrombogenic properties, and studying nanomaterial interaction with platelets is an important step toward understanding their hematocompatibility. Here we report evaluation of 12 formulations of PAMAM dendrimers varying in size and surface charge. Using a cell counter based method, light transmission aggregometry and scanning electron microscopy, we show that only large cationic dendrimers, but not anionic, neutral or small cationic dendrimers, induce aggregation of human platelets in plasma in vitro. The aggregation caused by large cationic dendrimers was proportional to the number of surface amines. The observed aggregation was not associated with membrane microparticle release, and was insensitive to a variety of chemical and biological inhibitors known to interfere with various pathways of platelet activation. Taken in context with previously reported studies, our data suggest that large cationic PAMAM dendrimers induce platelet aggregation through disruption of membrane integrity.

Carbon nanotubes activate store-operated calcium entry in human blood platelets.

Carbon nanotubes (CNTs) are known to potentiate arterial thrombosis in animal models, which raises serious safety issues concerning environmental or occupational exposure to CNTs and their use in various biomedical applications. We have shown previously that different CNTs, but not fullerene (nC60), induce the aggregation of human blood platelets. To date, however, a mechanism of potentially thrombogenic CNT-induced platelet activation has not been elucidated. Here we show that pristine multiwalled CNTs (MWCNTs) penetrate platelet plasma membrane without any discernible damage but interact with the dense tubular system (DTS) causing depletion of platelet intracellular Ca(2+) stores. This process is accompanied by the clustering of stromal interaction molecule 1 (STIM1) colocalized with Orai1, indicating the activation of store-operated Ca(2+) entry (SOCE). Our findings reveal the molecular mechanism of CNT-induced platelet activation which is critical in the evaluation of the biocompatibility of carbon nanomaterials with blood.

Carbon nanotubes activate blood platelets by inducing extracellular Ca2+ influx sensitive to calcium entry inhibitors.

To elucidate a mechanism of prothrombotic effects of carbon nanotubes (CNTs), we report here that multiwalled CNTs activate blood platelets by inducing extracellular Ca(2+) influx that could be inhibited by calcium channel blockers SKF 96365 and 2-APB. We also demonstrate platelet aggregating activity of different single-walled and multiwalled CNTs. In addition, we show that CNT-induced platelet activation is associated with a marked release of platelet membrane microparticles positive for the granular secretion markers CD62P and CD63.