title: Changes in lung volume and ventilation following transition from invasive to noninvasive respiratory support and prone positioning in preterm infants.
abstract: BACKGROUND
  To minimize secondary lung injury, ventilated preterm infants are extubated as soon as possible. To maximize extubation success, they are often placed in prone position. The effect of extubation and subsequent prone positioning on lung volumes is currently unknown.
  
  
  METHODS
  Changes in end-expiratory lung volume (ΔEELV), tidal volume (VT), and ventilation distribution were monitored during transition from endotracheal to nasal continuous positive airway pressure and following prone positioning using electrical impedance tomography. In addition, the continuous distending pressure (CDP) and oxygen need (FiO₂) were recorded.
  
  
  RESULTS
  Twenty preterm infants (GA 28.7 ± 1.7 wk) were included. Following extubation, the CDP decreased from 7.9 ± 0.5 to 6.0 ± 0.2 cmH₂O, while the FiO₂ remained stable. Both ΔEELV and VT increased significantly (P < 0.05) after extubation, without changing ventilation distribution. Prone positioning resulted in a further increase in ΔEELV (P < 0.01) and a decrease in respiratory rate. VT remained stable but its distribution clearly shifted toward the ventral lung regions.
  
  
  CONCLUSIONS
  Infants who are transitioned from invasive to noninvasive respiratory support are able to maintain their EELV and increase their VT. Prone positioning increases EELV and shifts tidal ventilation to the ventral lung regions. The latter suggests that infants should preferably be placed in prone position after extubation.
authors.affiliation: Department of Neonatology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Pauline S
authors.initials: PS
authors.lastname: van der Burg
authors.affiliation: Department of Neonatology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: Miedema
authors.affiliation: Department of Neonatology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Frans H
authors.initials: FH
authors.lastname: de Jongh
authors.affiliation: Department of Anesthesiology and Intensive Care Medicine, University Medical Center Schleswig-Holstein, Campus Kiel, Germany.
authors.forename: Inez
authors.initials: I
authors.lastname: Frerichs
authors.affiliation: Department of Neonatology, Emma Children's Hospital, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Anton H
authors.initials: AH
authors.lastname: van Kaam
mesh_terms: D045422:Continuous Positive Airway Pressure / Q000379:methods; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D007442:Intubation, Intratracheal / Q000379:methods; D008176:Lung Volume Measurements; D063087:Noninvasive Ventilation / Q000379:methods*; D016684:Prone Position / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology*; D012121:Respiration, Artificial / Q000379:methods*; D013990:Tidal Volume