Lung liquid clearance in preterm lambs assessed by magnetic resonance imaging.
Postnatal adaptation requires liquid clearance and lung aeration. However, their relative contribution to the expansion of functional residual capacity (FRC) has not been fully investigated. We studied evolution of lung liquid removal and lung aeration after birth in preterm lambs.



Lung liquid content and lung volume were assessed at birth and every 30 min over 2 h using magnetic resonance imaging (MRI) in three groups of lambs delivered by cesarean: preterm, late preterm, and late preterm with antenatal steroids. Lung function and mechanics of the respiratory system were also measured.



Lung liquid content increased by approximately 30% in the preterm group (P < 0.05), whereas it did not change significantly in the late preterm lambs. Antenatal steroids induced a 50% drop in the lung liquid content (P < 0.05). Total lung volume increased in all groups (P < 0.05) but was higher in the late preterm + steroids group relative to other groups (P < 0.05). Compliance and resistances of the respiratory system were significantly correlated with lung liquid content (P < 0.05).



FRC expansion results mainly from an increase in lung volume rather than a decrease in lung liquid in preterm and late preterm lambs. Antenatal steroids promote FRC expansion through increases in lung volume and liquid clearance.
EA4489 "Perinatal Environment and Health", FHU "1000 days 4 Health", University of Lille - Nord de France, Lille, France.|Pediatric Cardiology Unit, Department of Pediatrics, Lille University Hospital, Lille, France.
Ali
A
Houeijeh
EA4489 "Perinatal Environment and Health", FHU "1000 days 4 Health", University of Lille - Nord de France, Lille, France.|Department of Neonatology, Maternity, Amiens University Hospital, Amiens, France.
Pierre
P
Tourneux
Department of Neonatology and Maternity, Jeanne de Flandre Hospital, Lille University Hospital, Lille, France.
Sébastien
S
Mur
EA4489 "Perinatal Environment and Health", FHU "1000 days 4 Health", University of Lille - Nord de France, Lille, France.|Pediatric Surgery Unit, Department of Pediatrics, Lille University Hospital, Lille, France.
Estelle
E
Aubry
Plateforme Imagerie du Vivant, University of Lille, Nord de France, Lille, France.
Romain
R
Viard
EA4489 "Perinatal Environment and Health", FHU "1000 days 4 Health", University of Lille - Nord de France, Lille, France.|Pediatric Surgery Unit, Department of Pediatrics, Lille University Hospital, Lille, France.
Dyuti
D
Sharma
EA4489 "Perinatal Environment and Health", FHU "1000 days 4 Health", University of Lille - Nord de France, Lille, France.|Department of Neonatology and Maternity, Jeanne de Flandre Hospital, Lille University Hospital, Lille, France.
Laurent
L
Storme
D000818:Animals; D000831:Animals, Newborn; D001724:Birth Weight; D005652:Functional Residual Capacity; D008168:Lung / Q000000981:diagnostic imaging* / Q000502:physiology*; D008170:Lung Compliance; D008279:Magnetic Resonance Imaging; D047928:Premature Birth; D012119:Respiration; D012129:Respiratory Function Tests; D012756:Sheep; D034561:Sheep, Domestic; D013990:Tidal Volume; D013997:Time Factors