ABSTRACT
Beside alveoli, surface active material plays an important role in the airway physiology. In the upper airways it primarily serves in local defense. Lower airway surfactant stabilizes peripheral airways, provides the transport and defense, has barrier and anti-edematous functions, and possesses direct relaxant effect on the smooth muscle. We tested in vitro the effect of two surfactant preparations Curosurf® and Alveofact® on the precontracted smooth muscle of intra- and extra-pulmonary airways. Relaxation was more pronounced for lung tissue strip containing bronchial smooth muscle as the primary site of surfactant effect. The study does not confirm the participation of ATP-dependent potassium channels and cAMP-regulated epithelial chloride channels known as CFTR chloride channels, or nitric oxide involvement in contractile response of smooth muscle to surfactant.By controlling wall thickness and airway diameter, pulmonary surfactant is an important component of airway physiology. Thus, surfactant dysfunction may be included in pathophysiology of asthma, COPD, or other diseases with bronchial obstruction.
Subject(s)
Lung/drug effects , Muscle Relaxation/drug effects , Muscle, Smooth/drug effects , Pulmonary Surfactants/pharmacology , Trachea/drug effects , Animals , Biological Products/pharmacology , Cystic Fibrosis Transmembrane Conductance Regulator/antagonists & inhibitors , Cystic Fibrosis Transmembrane Conductance Regulator/metabolism , Dose-Response Relationship, Drug , Enzyme Inhibitors/pharmacology , Glyburide/pharmacology , Glycine/analogs & derivatives , Glycine/pharmacology , Guinea Pigs , Humans , Hydrazines/pharmacology , KATP Channels/antagonists & inhibitors , KATP Channels/metabolism , Lung/physiology , Muscle Relaxation/physiology , Muscle, Smooth/physiology , NG-Nitroarginine Methyl Ester/pharmacology , Nitric Oxide Synthase/antagonists & inhibitors , Nitric Oxide Synthase/metabolism , Phospholipids/pharmacology , Tissue Culture Techniques , Trachea/physiologyABSTRACT
European Consensus Guidelines (ECG) on the management of respiratory distress syndrome (RDS) have been developed and updated twice since 2007 reflecting changes in practice as new evidence emerges. The aim of this study was to evaluate the progress in clinical outcome of babies after the implementation of the updated ECG in 2010. Forty-eight neonates born in 2002-2003 (Group 02/03; n = 15) and in 2012-2013 (Group 12/13; n = 33) at gestational age of 26.2 ± 1.7 weeks were included into this retrospective study. Resuscitation procedures, ventilation support, and postnatal administration of surfactant were assessed. In Group 12/13, compared with Group 02/03, there was a higher rate of maternal corticosteroid prophylactic treatment (33 % vs. 0 %, p < 0.001), more children received primary nasal continuous positive airway pressure (nCPAP) (54.5 % vs. 20 %, p < 0.01) and repeated doses of surfactant (33 % vs. 0 %, p < 0.001), and had a reduced rate of mortality, bronchopulmonary dysplasia, and necrotizing enterocolitis. We conclude that the management of extremely preterm newborns improved considerably over the decade resulting in a significant reduction of mortality and morbidity.
