Does negative expiratory pressure influence performances of spirometry in older patients?

The aim of this study is to assess the influence of the negative expiratory pressure (NEP) technique on the performance of maximal expiratory manoeuvre in elderly patients. Firstly, the authors studied how NEP (at 5 and 10 cmH2O, NEP5 and NEP10) influences forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) in 60 young healthy volunteers, in order to assess the fluctuations of the method. In the second part of the study, 65 successive elderly inpatients (>70 yrs old) were examined. In this group, 15 elderly patients were unable to perform the manoeuvre, 27 had a normal function, 14 had a lung function with obstructive pattern and nine with restrictive pattern. In young subjects, FVC during NEP5 and NEP10 compared to baseline values was 101+/-5%, and 103+/-5%, respectively, and FEV1 was 100+/-4% and 101+/-5%, respectively. In elderly patients with normal function, FVC during NEP5 and NEP10 compared to baseline values was 99+/-14% and 109+/-23%, respectively, and FEV1 was 97+/-9% and 104+/-13%, respectively. There were no relevant effects of the NEP application on FVC or FEV1 values in elderly patients with an obstructive or restrictive pattern. In elderly patients, the use of the negative expiratory pressure technique during maximal expiratory manoeuvres provides little complementary information compared to a classical manoeuvre. The negative expiratory pressure technique did not modify the initial diagnosis when compared with the classical manoeuvre.