[Comparison of four techniques for the measurement of lung volumes and airway resistances by plethysmography].
OBJECTIVE
To search influence of measurement technique of thoracic gas volume(Vgt) and airway resistance(Raw) by plethysmography on results.


METHODS
20 healthy subjects, aged 22.75 + 0.40 years were studied. Vgt and Raw were measured by series of gentle panting manoeuvres (GPM) or calm respiration (CR) before and after closure of a shutter valve. So, four methods were compared : method 1 (M1) CR before ahd after, method 2 (M2): CR before and GPM after, method 3 (M3) GPM before and CR after, and method 4 (M4): GPM before and after the closure of the shutter valve. Five tests were maked with each method.


RESULTS
There is no significant inter-tests variability with each method. Raw(cm H2O/L/s) measured by M1 and M2 were so elevated if compared to M3 and M4 (M1 : 2.65 + 0.102; M2: 2.47 + 0.171; M3: 1.21 + 0.080; M4: 1.30 + 0.102 ; p < 0.05). There is also a significant variability intermethods in Vgt I): (M1: 3.53 + 0.188; M2 : 3.60 + 0.203; M3 : 3.91 + 0.262; M4: 3.84 + 0.247; p < 0.05).


CONCLUSIONS
The plethysmography measurement method must be considered in the interpretation of Vgt and Raw values.
Masmoudi
Kaouthar
K
Service d'explorations fonctionnelles, CHU. H. Bourguiba, Sfax, Tunisie.
Zouari
Nouri
N
D000328:Adult; D000403:Airway Resistance; D005260:Female; D006801:Humans; D008176:Lung Volume Measurements / Q000379:methods*; D008297:Male; D010991:Plethysmography / Q000379:methods*; D012016:Reference Values