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Preterm rabbit lung tissue mechanics: Maturational changes and effect of antenatal steroids
Author(s) -
Debeer Anne,
Flemmer Andreas W.,
Lewi Paul J.,
Beheydt Stijn,
De Buck Frederik,
Zimmermann Luc J.,
Naulaers Gunnar,
Deprest Jan A.
Publication year - 2010
Publication title -
pediatric pulmonology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.866
H-Index - 106
eISSN - 1099-0496
pISSN - 8755-6863
DOI - 10.1002/ppul.21191
Subject(s) - betamethasone , medicine , fetus , gestation , placebo , gestational age , lung , airway resistance , respiratory physiology , pulmonary compliance , pregnancy , endocrinology , anesthesia , pathology , biology , genetics , alternative medicine
Aim: Describe lung tissue and central airway mechanics using forced oscillation in preterm rabbits at different gestational ages and after maternal administration of betamethasone (BM). Methods: One hundred twelve fetuses from 54 does were studied. Ventilation was done using a Flexivent® (Scireq, Montreal, Canada). Resistance (Rrs), compliance/bodyweight (Crs/bw), Newtonian resistance (Rn), tissue damping (G L ), and elastance (H L ) were assessed. Maturational changes were studied in normal controls at days 27–31. The effect of BM (0.05 mg/kg on days 25 and 26) or placebo was studied in preterm fetuses at days 27, 28, and 29. Results: In unmanipulated control fetuses, Rrs decreased and Crs/bw increased with advancing gestation. Rn remained stable while G L and H L decreased. After day 29 no differences in pulmonary mechanics were observed. At 28 days Rrs and Crs/bw in BM and placebo fetuses were better compared to controls. At 29 days, Crs/bw and Rrs were higher, respectively, lower in control fetuses than BM or placebo exposed pups. Conclusion: Maturational changes in preterm rabbits occur mainly up to day 29 of gestation and are largely due to changes in tissue mechanics. Maternal BM injection improves lung mechanics at 28 days but placebo has equal effects. Pediatr Pulmonol. 2010; 45:349–355. © 2010 Wiley‐Liss, Inc.