Positional effects on lung mechanics of ventilated preterm infants with acute and chronic lung disease.
BACKGROUND
The role of prone position in preterm infants has not been completely clarified. We investigated prone versus supine posture-related changes in respiratory system resistance (Rrs) and reactance (Xrs) measured by the Forced Oscillation Technique (FOT) in mechanically ventilated preterm newborns.


METHODS
Patients were studied in the supine versus prone positions in random order. Oxygen saturation, transcutaneous partial pressure of oxygen (ptcO2 ), carbon dioxide (ptcCO2 ), Rrs and Xrs were measured in each position.


RESULTS
Nine patients with respiratory distress syndrome (RDS) and nine with evolving broncho-pulmonary dysplasia (BPD) were studied. Rrs was, on average, 9.8 (1.3, 18.3 as 95%CI) cmH2 O*s/l lower in the prone compared to the supine position (P = 0.02), while no differences in Xrs, ptcO2 , ptcCO2 , and breathing pattern were observed between postures. Only patients with evolving BPD showed a significant reduction of Rrs from 69.0 ± 27.4 to 53.0 ± 16.7 cmH2 O*s/l, P = 0.01. No significant correlations were found between changes in lung mechanics and ptcO2 , ptcCO2 , or breathing pattern.


CONCLUSIONS
On short-term basis, prone positioning does not offer significant advantages in lung mechanics in mechanically ventilated infants with RDS, while it is associated with lower Rrs values in patients with evolving BPD.
NICU, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico-Università Degli Studi di Milano, Milan, Italy.
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Vendettuoli
TBMLab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy.
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Veneroni
TBMLab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy.
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Zannin
NICU, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico-Università Degli Studi di Milano, Milan, Italy.
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Mercadante
NICU, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico-Università Degli Studi di Milano, Milan, Italy.
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Matassa
TBMLab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy.
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Pedotti
NICU, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico-Università Degli Studi di Milano, Milan, Italy.
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Colnaghi
TBMLab, Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano University, Milan, Italy.
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Dellacà
NICU, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico-Università Degli Studi di Milano, Milan, Italy.
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Mosca
D001997:Bronchopulmonary Dysplasia / Q000628:therapy*; D002245:Carbon Dioxide / Q000097:blood; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007385:Intermittent Positive-Pressure Ventilation; D008297:Male; D010100:Oxygen / Q000097:blood; D016684:Prone Position; D012127:Respiratory Distress Syndrome, Newborn / Q000628:therapy*; D016683:Supine Position
D002245:Carbon Dioxide; D010100:Oxygen
infant pulmonary function; mechanical ventilation; neonatal pulmonary medicine