Effect of indacaterol on arterial blood gases in patients suffering from acute exacerbation of COPD.

AIM: The administration of ß2-agonists to patients with airways obstruction often results in transient decrease in PaO2 despite concomitant bronchodilation. This effect is potentially dangerous for patients suffering from acute exacerbation of COPD (AECOPD). In this study, we investigated the effect of indacaterol 150 µg and 300 µg on the arterial blood gas tensions of hospitalised patients with AECOPD. METHODS: We explored the acute effects on arterial blood gases and spirometry of two doses of indacaterol Breezhaler (150 and 300 µg) in 12 patients hospitalised because of an AECOPD in 2 non-consecutive days under open-label, randomized, crossover conditions, with blind evaluation. Blood specimens were taken just before the inhalation and at 15, 30, 60, 120, 240 and 360 min after inhalation of each treatment, and spirometry was performed at the same time points. RESULTS: Both doses of indacaterol did not cause significant changes in blood gases, although some patients with relatively well-preserved PaO2 presented transient episodes of oxygen desaturation that normalize spontaneously in a very short time. Moreover, they induced a significant mean increase in FEV1 and FVC, although the improvement caused by indacaterol 300 µg was larger. CONCLUSIONS: Indacaterol up to 300 µg is a potent bronchodilator that may induce small, transient decrease in PaO2 mainly in patients with relatively well-preserved PaO2. There appeared to be no clinical consequences of these PaO2 abnormalities in patients suffering from AECOPD.

Iron laden macrophages in idiopathic pulmonary fibrosis: the telltale of occult alveolar hemorrhage?

RATIONALE: A number of observations suggest that iron accumulates in the lungs of patients with idiopathic pulmonary fibrosis (IPF) with vascular abnormalities, including pulmonary hypertension. OBJECTIVES: The aim of this study was to determine the prevalence and intensity of accumulation of alveolar epithelial lining fluid (ELF) iron and of alveolar macrophage hemosiderin in IPF and its relationship with disease severity. METHODS: Forty seven IPF patients and 14 healthy controls were retrospectively evaluated for iron accumulation in the lower respiratory tract using total iron spectrophotometric measures and for hemosiderin accumulation using the Perls' stain with the Golde score. MEASUREMENTS AND MAIN RESULTS: Total iron levels in ELF were significantly increased in IPF patients compared to non-smoking controls (p < 0.05); there were no differences with healthy smokers (p = 0.2). Hemosiderin accumulation in alveolar macrophages was similar in never smoking and ever smoking IPF patients (p = 0.5), was significantly higher in IPF patients than in both smoking and non-smoking healthy controls (p < 0.05, all comparisons) and was positively correlated with echocardiographic estimates of pulmonary artery systolic pressure (p < 0.05) and with increasing disease severity scores (p < 0.05). CONCLUSIONS: The data show exaggerated accumulation of iron in IPF broncho-alveolar ELF and alveolar cells with no association with tobacco smoke, thus suggesting, occult pulmonary hemorrhage as a likely cause.

A 6MWT index to predict O2 flow correcting exercise induced SpO2 desaturation in ILD.

INTRODUCTION: Ambulatory oxygen (O2) is prescribed to interstitial lung disease (ILD) patients with mild hypoxemia, breathlessness and dyspnea on exertion. Oxygen titration is generally done with the 6 minute walk test (6MWT) to determine the O2 flow preventing oxygen saturation by pulse oximetry (SpO2) from falling below 88%. His study was designed to generate a 6MWT index predicting the O2 flow allowing completion of the 6MWT without oxygen desaturation. METHODS: Oxygen titration data from a group of 66 ILD patients and 30 controls, were used to generate the algorithm determining an index (O2-GAP) predicting oxygen flow required to complete a 6MWT without desaturation below 88%. This index was validated in a group of 93 ILD patients. RESULTS: The O2-GAP index, as obtained from the derivation population, (r(2) = 0.97, p < 0.001) was shown to correctly predict the oxygen flow required to complete the 6MWT without SpO2 falling below 88% validated in the validation population (r(2) = 0.842; p < 0.001). CONCLUSIONS: The O2-GAP index appears to be a useful tool to titrate ambulatory O2 with a single 6MWT on room air in ILD patients with breathlessness and dyspnea on exertion.

Energy expenditure and impact of bronchodilators in COPD patients.

28 Consecutive COPD patients performed four 6-minute walking tests (6-MWTs) in 2 different days before and 2, 4 and 6h after the inhalation of formoterol 12microg or tiotropium 18microg, respectively. Physical activity during each 6-MWT was assessed by the SenseWear Armband. At each time also spirometry was performed. Both formoterol and tiotropium induced a significantly sustained bronchodilation and influenced hyperinflation. Formoterol significantly increased distance walked in 6min at 2h and at 4h, whereas tiotropium significantly increased it at all time points. There was a trend to an increase in calories and metabolic equivalents of task (METs) after formoterol and a decrease after tiotropium, but changes were not statistically significant. Total energy expenditure for each 6-MWT was not changed by formoterol, but decreased in significant manner 6h after the inhalation of tiotropium. Active energy expenditure at physical activity level of more than 3 METs decreased significantly after tiotropium at each 6-MWT, but not after formoterol. We did not find any significant correlation between the changes in lung function and those of parameters recorded with SenseWear Armband. Our study seems to indicate that tiotropium, but not formoterol, is able to reduce energy expenditure in COPD patients, although both drugs elicit significant bronchodilation and are able to increase the distance walked in 6min.