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.

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.

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.