Influence of preterm onset of inspiration on tidal breathing parameters in infants with and without CLD.
The preterm onset of inspiration (POI) is a well-known breathing strategy in newborns to increase their end-expiratory lung volume. The aim of this study was to investigate to which extent POI is related to tidal breathing (TB) parameters in healthy neonates (n=54) and infants with chronic lung diseases (CLD, n=45) with same postconceptional age. Using the deadspace free flow-through technique, 10-60 consecutive breaths were evaluated during quiet sleep and POI was derived from the averaged flow-volume loop considering the end-expiratory flow level. Respiratory rate (RR), ventilation (VE) and peak flows were significantly higher in CLD infants compared with controls. The incidence of POI did not differ significantly between both patient groups. POI is strongly associated with TB parameters describing the shape of flow profiles or flow-volume loops. In contrast, TB parameters, which depend only on breathing depth and rate (e.g., RR, VT, VE), were not significantly associated. The study shows that in infants TB parameters describing the flow profile may reflect differences in breathing strategy rather than impaired respiratory functions.
Schmalisch
Gerd
G
Clinic of Neonatology (Charité), Humboldt-University of Berlin, Schumannstrasse 20/21, D-10098, Berlin, Germany. gerd.schmalisch@charite.de
Wauer
Roland R
RR
Foitzik
Bertram
B
Patzak
Andreas
A
D002908:Chronic Disease; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D008171:Lung Diseases / Q000503:physiopathology*; D011446:Prospective Studies; D012123:Pulmonary Ventilation / Q000502:physiology*; D012119:Respiration; D012129:Respiratory Function Tests / Q000379:methods; D013990:Tidal Volume / Q000502:physiology