RT Journal Article
SR Electronic
T1 Breath by breath specific airway resistance during panting in children
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP P4613
VO 40
IS Suppl 56
A1 Laurianne Coutier
A1 Claude Bonabel
A1 Bruno Demoulin
A1 Iulia Ioan
A1 Than Le Tuan
A1 Silvia Varechova
A1 Cyril Schweitzer
A1 François Marchal
YR 2012
UL http://erj.ersjournals.com/content/40/Suppl_56/P4613.abstract
AB Rationale. Panting is the optimal way to minimize the phase lag between the plethysmographic volume compression signal (Vplet) and airflow due to the thermal artifact when measuring specific airway resistance (sRaw). A drawback in children is that the end expiratory lung volume may be observed to increase during the measurement. It is not known to what extent sRaw is altered by the breathing strategy.The hypothesis was tested here that increased end expiratory lung volume during panting does not impact significantly on sRaw.Objective. To test whether increased end expiratory lung level within the sRaw acquisition results in a systematic trend with time.Methods. sRaw was measured in 10 children panting in a custom made pressure plethysmograph. Thirty measurements (1-5 per subject) that displayed a steady increase in end expiratory lung level throughout at least 4 breaths were reanalyzed breath by breath.Results. Panting frequency (mean ± SD) was 3.1 ± 0.5 Hz. sRaw was found to increase significantly throughout the acquisition (p = 0.006).View this table:significant breath by breath increase in sRaw (hPa.sec) during panting in 10 childrenConclusion: The progressive increase in end-expiratory lung volume during panting in children is associated with parallel increase in sRaw. This may be explained by non linearities in the Vplet - airflow relationship while the end expiratory lung volume increases in relation with imbalance between inspiratory and expiratory efforts. The clinical relevance is not clear and desserves further evaluation.