title: Effect of positive end-expiratory pressure on ductal shunting and systemic blood flow in preterm infants with patent ductus arteriosus.
abstract: BACKGROUND
  Left to right (L-R) shunting through a patent ductus arteriosus (PDA) can reduce systemic and cerebral blood flow in preterm infants. To minimize this, the positive end-expiratory pressure (PEEP) is often raised to increase pulmonary vascular resistance and reduce L-R shunting. The effects of this maneuver on systemic and cerebral hemodynamics and oxygenation are not well documented.
  
  
  OBJECTIVE
  To compare the effects of different PEEP on the left ventricular output (LVO), superior vena cava (SVC) flow, LVO/SVC flow ratio, cerebral oxygenation (CrSO2) and gas exchange in mechanically ventilated preterm infants with PDA.
  
  
  METHODS
  Sixteen mechanically ventilated infants of 23-30 weeks' gestational age with L-R shunting through the PDA were studied. Ultrasound measurements of LVO and SVC flow, CrSO2, arterial oxygen saturation and transcutaneous CO2 tension (TcPCO2) obtained at PEEP of 2 and 8 cm H2O were compared with baseline values at 5 cm H2O.
  
  
  RESULTS
  There was a small but significant reduction in LVO and the LVO/SVC flow ratio at PEEP of 8 compared to 5 cm H2O. SVC flow and CrSO2 did not differ significantly.
  
  
  CONCLUSIONS
  Increasing PEEP to 8 cm H2O in ventilated preterm infants with a PDA produced a modest decrease in L-R ductal shunting as indicated by a lower LVO/SVC flow ratio. The higher PEEP did not have a significant effect on cerebral perfusion or oxygenation.
authors.affiliation: Division of Neonatology, Department of Pediatrics, University of Miami Miller School of Medicine, Miami, Fla., USA.
authors.forename: Maria Florencia
authors.initials: MF
authors.lastname: Fajardo
authors.forename: Nelson
authors.initials: N
authors.lastname: Claure
authors.forename: Sethuraman
authors.initials: S
authors.lastname: Swaminathan
authors.forename: Sumbal
authors.initials: S
authors.lastname: Sattar
authors.forename: Amelia
authors.initials: A
authors.lastname: Vasquez
authors.forename: Carmen
authors.initials: C
authors.lastname: D'Ugard
authors.forename: Eduardo
authors.initials: E
authors.lastname: Bancalari
mesh_terms: D001921:Brain / Q000378:metabolism; D004374:Ductus Arteriosus, Patent / Q000503:physiopathology* / Q000628:therapy*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D010100:Oxygen / Q000378:metabolism; D011175:Positive-Pressure Respiration / Q000379:methods*; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology*; D012121:Respiration, Artificial / Q000379:methods*; D016896:Treatment Outcome; D014655:Vascular Resistance / Q000502:physiology; D014683:Vena Cava, Superior / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology
chemical_list: D010100:Oxygen