Hemodynamic effects of positive end-expiratory pressure during partial liquid ventilation in newborn lambs.

Background/purpose: The aim of this study was to compare the effect of positive end-expiratory pressure (PEEP) application on hemodynamics, lung mechanics, and oxygenation in the intact newborn lung during conventional ventilation (CV) and partial liquid ventilation (PLV) at functional residual capacity (FRC). CV or PLV modes of ventilation do not affect hemodynamics nor the optimum PEEP for oxygenation.

Methods: Seven newborn lambs (1 to 3 days old) were instrumented to measure pulmonary hemodynamics and airway mechanics.

Gastroschisis and Hirschsprung's disease: a rare combination.

The authors report on a neonate with gastroschisis repaired at birth who later had abdominal distension, emesis, feeding intolerance, and an abnormal stooling pattern. Total colon and partial small bowel aganglionosis (TCAS), or Hirschsprung's disease, was diagnosed subsequently. This is the first report of this combination of gastrointestinal anomalies.

Form and function of fetal and neonatal pulmonary arterial bifurcations.

Bifurcation is a basic form of vascular connection. It is composed of a parent vessel of diameter d(0), and two daughter vessels, d(1) and d(2), where d(0) > d(1) >/= d(2). Optimal values for the bifurcation area ratio, beta = (d(1)(2) + d(2)(2))/d(0)(2), and the junction exponent, x, in d(0)(x) = d(1)(x) + d(2)(x), are postulated to be universal in nature.

Effects of correction of hypocalcemia on cardiac function in the newborn lamb.

The effect of correction of hypocalcemia on cardiac function in the neonate is unclear. Therefore, we evaluated changes in hemodynamic variables and cardiac contractility in a hypocalcemic neonatal lamb model. Baseline serum ionized hypocalcemia was induced via chelation with intravenous EGTA.

Role of nitric oxide in cardiovascular responses to endotoxemia in neonatal lambs.

To determine whether systemic cardiovascular responses to gram-negative endotoxemia are mediated by nitric oxide, we evaluated time-dependent changes in contractility and hemodynamics in a neonatal sheep model subjected to nitric oxide synthesis inhibition with L-Name (Nomega-nitro-L-arginine methyl ester). Four groups were studied: control (C), endotoxin (E), endotoxin L-Name where the nitric oxide synthase inhibitor was given prior to endotoxin (ELN), and a control L-Name group pretreated with L-Name (CLN). The contractility, measured as end-systolic elastance (Ees), increased transiently in the E group and then returned to baseline.