PT  - JOURNAL ARTICLE
AU  - N Koulouris
AU  - DA Mulvey
AU  - CM Laroche
AU  - M Green
AU  - J Moxham
TI  - Comparison of two different mouthpieces for the measurement of Pimax and Pemax in normal and weak subjects
AID  - 10.1183/09031936.93.01090863
DP  - 1988 Oct 01
TA  - European Respiratory Journal
PG  - 863--867
VI  - 1
IP  - 9
4099  - http://erj.ersjournals.com/content/1/9/863.short
4100  - http://erj.ersjournals.com/content/1/9/863.full
SO  - Eur Respir J1988 Oct 01; 1
AB  - We investigated the effect of mouthpiece design on maximum static expiratory (PEmax) and inspiratory (PImax) mouth pressures. We measured PEmax from total lung capacity (TLC) and PImax from residual volume (RV) in 21 healthy volunteers, and in 40 patients referred for respiratory muscle testing. We compared two different mouthpieces, a semi-rigid plastic flanged type fitting inside the lips, and a 4 cm diameter rubber tube held against the lips. The tube mouthpiece gave significantly higher values for PEmax (p less than 0.02) in all subjects. PImax was also significantly higher (p less than 0.005) with the tube mouthpiece in subjects who recorded normal pressures. We conclude that maximum pressures are obtained in all normal subjects with the rubber tube mouthpiece, and that differences in quoted normal ranges of maximum static respiratory pressures reflect in part the design of the mouthpiece and the way in which it was used.