Surfactant administration for neonatal respiratory distress does not improve lung interstitial fluid clearance: echographic and experimental evidence.
ABSTRACT Recent ultrasonographic studies suggest that the administration of surfactant to preterm infants with respiratory distress syndrome (RDS) does not affect lung water clearance. The purpose of the study was also to look at clearance of lung water in preterm rabbits receiving surfactant.
Lung ultrasound was performed in 73 neonates at different gestational ages (range 23-34 weeks) with radiological and clinical signs of RDS, before and after surfactant administration. In premature rabbits (28-29 days' gestational age), either receiving or not receiving surfactant, we followed the time course of lung water balance considering the wet weight/dry weight ratio, the morphology and compliance of alveoli and pulmonary interstitial pressure.
In all RDS infants lung ultrasound images consistently showed a generalized increase in extravascular lung fluid which remained unchanged after surfactant administration and did not affect the rate of fluid clearance. Surfactant administration in premature rabbits did not improve the time course of lung fluid clearance.
Data from ultrasound in preterm babies are confirmed by animal experiments.
- Chest 03/2011; 139(3):730-1. DOI:10.1378/chest.10-2338 · 7.13 Impact Factor
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ABSTRACT: The initiation of ventilation in preterm, surfactant-deficient sheep without positive end-expiratory pressure (PEEP) causes airway injury and lung inflammation. We hypothesized that PEEP and surfactant treatment would decrease the lung injury from initiation of ventilation with high tidal volumes. Fetal sheep at 128-day gestational age were randomized to ventilation with: 1) no PEEP, no surfactant; 2) 8-cmH(2)O PEEP, no surfactant; 3) no PEEP + surfactant; 4) 8-cmH(2)O PEEP + surfactant; or 5) control (2-cmH(2)O continuous positive airway pressure) (n = 6-7/group). After maternal anesthesia and hysterotomy, the head and chest were exteriorized, and the fetus was intubated. While maintaining placental circulation, the fetus was ventilated for 15 min with a tidal volume escalating to 15 ml/kg using heated, humidified, 100% nitrogen. The fetus then was returned to the uterus, and tissue was collected after 30 min for evaluation of early markers of lung injury. Lambs receiving both surfactant and PEEP had increased dynamic compliance, increased static lung volumes, and decreased total protein and heat shock proteins 70 and 60 in bronchoalveolar lavage fluid compared with other groups. Ventilation, independent of PEEP or surfactant, increased mRNA expression of acute phase response genes and proinflammatory cytokine mRNA in the lung tissue compared with controls. PEEP decreased mRNA for cytokines (2-fold) compared with groups receiving no PEEP. Surfactant administration further decreased some cytokine mRNAs and changed the distribution of early growth response protein-1 expression. The use of PEEP during initiation of ventilation at birth decreased early mediators of lung injury. Surfactant administration changed the distribution of injury and had a moderate additive protective effect.AJP Lung Cellular and Molecular Physiology 08/2011; 301(5):L712-20. DOI:10.1152/ajplung.00157.2011 · 4.04 Impact Factor
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ABSTRACT: Ultrasound of the thorax is particularly rewarding in children, because their unique thoracic anatomy provides many available acoustic windows into the chest. Newer ultrasound techniques can allow better understanding of lung disease. With minimum effort and creativity, chest ultrasound can provide important clinical information without radiation exposure or sedation sometimes required for computed tomography and magnetic resonance imaging.Radiologic Clinics of North America 09/2011; 49(5):825-46. DOI:10.1016/j.rcl.2011.06.008 · 1.83 Impact Factor