RT Journal Article
SR Electronic
T1 Long term sensitisation of cough and expiration reflex in adult rabbits by 48 hour postnatal normobaric hyperoxia
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P4600
VO 40
IS Suppl 56
A1 Silvia Varechova
A1 Bruno Demoulin
A1 Yanis Inglebert
A1 Than Le Tuan
A1 Anne Laure Leblanc
A1 Cyril Schweitzer
A1 François Marchal
YR 2012
UL http://erj.ersjournals.com/content/40/Suppl_56/P4600.abstract
AB Rationale. Cough is a frequent report in follow up studies of late premature children at school age. On the other ahnd, the experimental evidence exists in adult animals that the short term effect of acute hyperoxia is to down regulate cough. The hypothesis that neonatal exposure to hyperoxia may interfere with incidence of cough at school age has not been tested previously.The aim of the study was to determine whether postnatal administration of oxygen in pups alters the cough reflex in adult rabbits.Methods. Rabbits were exposed within the first 8 days of life to 48h normobaric hyperoxia (FIO2 > 93%; n = 12) or ambient air (control; n = 9). At age 3 - 4 months the animal was anesthetized, tracheotomized and subjected to a series of discrete mechanical stimulations of the trachea lasting 50, 150, 300 and 600ms. Each stimulus was quadrupled so as to total 24 stimulations per animal. Cough and expiration reflex were identified from breathing flow and volume, respectively as a forced expiratory effort preceded (cough) or not (expiration reflex) by an increased inspiration.Results. The incidence of either cough (66/288: 23%) or expiration reflex (124/288: 43%) in hyperoxic rabbits was significantly larger than its respective control (cough: 25/214: 12%; expiration reflex: 60/214: 28%; p = 0.0005).Conclusion. The experimental evidence of long term sensitisation of airway defensive reflexes in rabbits breathing high oxygen soon after birth favours a role for neonatal hyperoxia in the pathogenesis of chronic cough at school age in late premature children.