Assessment of concordance between diffusion of carbon monoxide through the lung using the 10 s breath-hold method, and the simultaneous NO/CO technique, in healthy participants.

INTRODUCTION: There is limited, large sample size, healthy control data comparing measurement of diffusing capacity of the lungs for carbon monoxide (DLCO) via the 10 s single-breath carbon monoxide uptake method (DLCO10) and using a DLCO-DLNO double diffusion test performed with a 5 s time of apnoea (DLCO5). OBJECTIVES: The primary objective was to compare DLCO5 and DLCO10 in healthy participants. The secondary objective was to evaluate the reproducibility of DLCO5. MATERIAL AND METHODS: We included medical students at Caen University Hospital, from 2008 to 2011. We performed a standard single-breath carbon monoxide uptake and combined DLCO and DLNO measurement for each participant. The combined test was repeated one week later. RESULTS: Among the 153 study participants, there was no statistically significant difference between the mean values of DLCO10 (10.2 ±â€¯2.2 mmol.min-1 kPa-1) and DLCO5 (10.3 ±â€¯2.2 mmol.min-1 kPa-1; paired t-test p = 0.19). Corrected for the same FiO2, DLCO5 was calculated at 10.5 ±â€¯2.3 mmol.min-1 kPa-1 and was significantly different from DLCO10 (paired t-test p < 0.001). DLCO5 deviates from 1,6 mmol.min-1 kPa-1 (4,6 mL.min-1. mmHg-1) or 15 % of DLCO10 (17 % above and 13% below, for 95 % of the subjects). Forty-seven participants were included in the DLCO5 reproducibility test. The 2 test sessions were carried out at 6 ±â€¯2 day intervals. Reproducibilities for DLCO, DLNO, DmCO and Vc was respectively 1.2 (11 %), 6.8 (13%), 16.5 (32 %), 12.5 (17 %) mmol.min-1 kPa-1. CONCLUSION: In healthy participants, discrepancies between DLCO measured during the double diffusion and DLCO measured on an apnoea of 10 s are quite large. It may be an indication that the Roughton and Forster interpretation to describe this type of measurements is inadequate.

[New approaches of inhaled steroid asthma management in mild to moderate asthma]. / Nouvelles modalités de prescription des corticoïdes inhalés dans l'asthme léger à modéré.

Inhaled corticosteroids (ICS) are the cornerstone of the management of asthma. Daily use allows to reduce mortality, intensity and frequency of exacerbations, to increase the control of symptoms of asthma and the quality of life of asthmatics patients and to reduce the decline of the lung function. A daily use of a weak dose of ICS allows to control the symptoms of asthma of the vast majority of mild to moderate asthmatics patients who account for about 75-80 % of the French asthmatic patients. An add-on strategy with a combination by ICS/LABA allows to decrease by 20 % the risk of an exacerbation compared with a treatment by CSI in monotherapy. "SMART" which consists in using a fixed ICS/LABA combination as a maintenance and reliever therapy had showed better results in the prevention of exacerbations that the use of the same combination associated with a SABA as a reliever therapy. This strategy is recommended by GINA at the same level of proof as the classical treatment. An "on-demand" use of a ICS/LABA combination according to symptoms is clearly less efficacious in terms of control of the symptoms than the classical strategy by ICS/LABA; but both strategies are identical in terms of prevention of exacerbations. The daily dose of ICS is 4 to 5 times less than in the daily ICS group. The clinical effectiveness and cost-effectiveness of a standard asthma self-management plan that advises patients to temporarily quadrupling the dose of ICS in case of asthma worsening can be an alternative and allow to reduce 20 % of clinically important asthma exacerbations.