title: Bi-level CPAP does not change central blood flow in preterm infants with respiratory distress syndrome.
abstract: BACKGROUND
  Current literature provides limited data on the hemodynamic changes that may occur during bi-level continuous positive airway pressure (CPAP) support in preterm infants. However, the application of a positive end-expiratory pressure may be transmitted to the heart and the great vessels resulting in changes of central blood flow.
  
  
  OBJECTIVE
  To assess changes in central blood flow in infants with respiratory distress syndrome (RDS) during bi-level CPAP support.
  
  
  METHODS
  A prospective study was performed in a cohort of 18 Very-Low-Birth-Weight Infants who were put on nasal CPAP support (4-5 cmH2O) because they developed RDS within the first 24-72 hours of life. Each subject was switched to bi-level CPAP support (Phigh 8 cmH2O, Plow 4-5 cmH2O, Thigh 0.5-0.6 seconds, 20 breaths/min) for an hour. An echocardiographic study and a capillary gas analysis were performed before and after the change of respiratory support.
  
  
  RESULTS
  No differences between n-CPAP and bi-level CPAP in left ventricular output (LVO, 222.17 ± 81.4 vs 211.4 ± 75.3 ml/kg/min), right ventricular output (RVO, 287.8 ± 96 vs 283.4 ± 87.4 ml/kg/min) and superior vena cava flow (SVC, 135.38 ± 47.8 vs 137.48 ± 46.6 ml/kg/min) were observed. The hemodynamic characteristics of the ductus arteriosus were similar. A significant decrease in pCO2 levels after bi-level CPAP ventilation was observed; pCO2 variations did not correlate with modifications of central blood flow (LVO: ρ=0.11, p=0,657; RVO: ρ=-0.307, p=0.216; SVC: ρ=-0.13, p=0.197).
  
  
  CONCLUSIONS
  Central blood flow doesn't change during bi-level CPAP support, which could become a hemodinamically safe tool for the treatment of RDS in preterm infants.
authors: Giulia
authors: G
authors: Aquilano
authors: Neonatology and Neonatal Intensive Care Unit, Department of Medical and Surgical Sciences, St, Orsola-Malpighi Hospital - University of Bologna, Via Massarenti, 11 40138 Bologna, Italy. silvia.galletti4@unibo.it.
authors: Silvia
authors: S
authors: Galletti
authors: Arianna
authors: A
authors: Aceti
authors: Francesca
authors: F
authors: Vitali
authors: Giacomo
authors: G
authors: Faldella
mesh_terms: D001784:Blood Gas Analysis; D002302:Cardiac Output / Q000502:physiology; D045422:Continuous Positive Airway Pressure / Q000379:methods*; D003326:Coronary Circulation / Q000502:physiology*; D004373:Ductus Arteriosus / Q000000981:diagnostic imaging / Q000502:physiology; D018618:Echocardiography, Doppler, Color; D018619:Echocardiography, Doppler, Pulsed; D005260:Female; D054085:Foramen Ovale / Q000000981:diagnostic imaging / Q000502:physiology; D006352:Heart Ventricles / Q000000981:diagnostic imaging; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D019102:Infant, Very Low Birth Weight / Q000502:physiology; D007363:Intensive Care Units, Neonatal; D008297:Male; D011446:Prospective Studies; D012127:Respiratory Distress Syndrome, Newborn / Q000628:therapy*; D014683:Vena Cava, Superior / Q000000981:diagnostic imaging / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology