Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 12475840

Inspiratory capacity and decrease in lung hyperinflation with albuterol in COPD.

Roberto Duranti·Mario Filippelli·Roberto Bianchi·Isabella Romagnoli·Riccardo Pellegrino·Vito Brusasco·Giorgio Scano
View original source ↗Export metadata ↓

Abstract

STUDY OBJECTIVES: Inspiratory capacity (IC) has been proposed as a simple method to assess acute changes in functional residual capacity (FRC) with bronchodilation, assuming that total lung capacity (TLC) is unchanged. This assumption is based on studies using body plethysmography, which may not accurately measure TLC in severely obstructed subjects. The aim of this study is to validate the use of IC measured by optoelectronic plethysmography (OEP) [ICOEP], a noninvasive technique capable of computing changes in absolute lung volumes with great accuracy. MEWTHODS AND MEASUREMENTS: We studied 13 subjects with COPD in clinically stable condition at baseline and after 200 microg of inhaled albuterol. Changes in lung volumes were obtained from changes in chest wall volume (Vcw) measured by OEP and were compared with those measured by standard techniques. RESULTS: Albuterol treatment caused a small but significant increase in FEV(1) and FVC, a significant decrease of Vcw at FRC (VcwFRC), but no changes of Vcw at TLC (VcwTLC) and breathing pattern variables. The reduction of VcwFRC was not correlated with either spirometric or breathing-pattern variables. IC measured with a pneumotachograph was highly correlated with and not significantly different from ICOEP (p < 0.001). CONCLUSIONS: A single dose of inhaled albuterol does not significantly modify VcwTLC in subjects with COPD, thus validating the use of IC to measure changes of FRC in the assessment of reversibility of airway obstruction.

Explore related subjects

Administration, InhalationAgedAlbuterolBronchodilator AgentsForced Expiratory Flow RatesFunctional Residual CapacityHumansInspiratory CapacityLungLung Volume MeasurementsPlethysmographyPulmonary Disease, Chronic ObstructiveJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Roberto Duranti, Mario Filippelli, Roberto Bianchi, Isabella Romagnoli, Riccardo Pellegrino, Vito Brusasco, Giorgio Scano. 2002. Inspiratory capacity and decrease in lung hyperinflation with albuterol in COPD.. https://doi.org/10.1378/chest.122.6.2009

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2003

Liquid chromatographic-atmospheric pressure chemical ionization mass spectrometric analysis of opiates and metabolites in rat urine after inhalation of opium.

To examine the urinary excretion of opiates and their metabolites following inhalation exposure of rats to opium, analytical procedures for the simultaneous determination of the compounds in opium, the vapor derived by the volatilization of opium and the urine of rats exposed to the opium vapor were developed using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS). Seven compounds were determined in the opium, namely morphine, codeine, thebaine, noscapine, papaverine, meconic acid and meconin. All seven were extracted with 2.5% acetic acid solution and subjected to LC-APCI-MS analysis. The separation was performed on an ODS column in acetonitrile-50 mM ammonium formate buffer (pH 3.0) using a linear gradient program and quantitative analysis was carried out in the selected ion monitoring mode ([M+H](+)). For the analysis of the volatilization of opium, the opium (1 g) was added to a glass pipe, which was then heated at 300 degrees C for 20 min. Negative pressure (air flow-rate; 300 ml/min) was used to draw the vapor through a series of glass wool and methanol traps. The total amount of each compound in the vapor was estimated by measurement of the compounds trapped in the glass wool and methanol. Wister rats (n=3) were exposed to the vapor derived from the volatilization system and the urinary amounts (0-72 h) of the six opiates and metabolites including morphine-3-grucronide (M3G) and morphine-6-grucronide (M6G) were measured after solid-phase extraction. The calibration curves for those compounds in the rat urine were linear over the concentration range 10-500 ng/ml. The recoveries for each analyte from the rat urine sample spiked with standard solution were generally greater than 80%, and the relative standard deviation for the analytical procedure was less than 8% with the exception of meconin. After inhalation exposure of rats to opium, M3G (5.45-14.38 micro g), morphine (2.27-4.65 micro g), meconin (0.54-1.85 micro g), codeine (0.54-1.85 micro g), noscapine (0.34-0.40 micro g) and papaverine (0.01-0.04 micro g) were detected in the urine over 72 h. However, only trace levels of thebaine were observed despite it being one of the major alkaloids found in the opium. On the other hand, a relatively large amount of meconin was detected in the vapor and the urine as compared with the opium. It is suggested that the presence of meconin in biological fluids could be indicative of opium ingestion by inhalation.

Administration, Inhalation↗
PubMed2003

Planar gamma scintigraphy--points to consider when quantifying pulmonary dry powder aerosol deposition.

Methodological aspects of planar gamma scintigraphy used to quantify pulmonary aerosol deposition were investigated using an experimental dry powder formulation. Particles of micronized salbutamol sulphate were labelled with technetium-99m and admixed to an ordered mixture of unlabelled micronized salbutamol sulphate and larger carrier particles of lactose. The radioaerosol was administered to 24 healthy subjects, 12 in each of two consecutive, similarly designed studies. Pulmonary deposition was determined using two methods: repeated planar imaging, and pharmacokinetic assessments following charcoal co-administration to prevent gastrointestinal salbutamol absorption. After due consideration had been taken to ensure appropriate radiolabelling, image acquisition and processing procedures, a scintigraphic estimate of 26.2% (with 95% confidence interval of 24.2-28.4%) was obtained, which did not significantly differ from the pharmacokinetic estimate of 26.4% (24.4-28.7%). In summary, pre-study validation of the radiolabelling technique, quality control of radioaerosols produced during the study, correction for re-distribution of radiolabel from the lungs, selection of regions of interest, assessment of lung contours, correction for tissue attenuation of gamma rays and establishment of the actual recovery of radioactivity in the scintigraphic measurements could potentially affect the accuracy of the scintigraphic estimate of pulmonary deposition and, thus, should be carefully considered in the design or evaluation of any such study.

Administration, Inhalation↗
PubMed2003

Globose basal cells are required for reconstitution of olfactory epithelium after methyl bromide lesion.

Despite a remarkable regenerative capacity, recovery of the mammalian olfactory epithelium can fail in severely injured areas, which subsequently reconstitute as aneuronal respiratory epithelium (metaplasia). We contrasted the cellular response of areas of the rat epithelium that recover as olfactory after methyl bromide lesion with those undergoing respiratory metaplasia in order to identify stem cells that restore lesioned epithelium as olfactory. Ventral olfactory epithelium is at particular risk for metaplasia after lesion and patches of it are rendered acellular by methyl bromide exposure. In contrast, globose basal cells (GBCs, marked by staining with GBC-2) are preserved in surrounding ventral areas and uniformly throughout dorsal epithelium, which consistently and completely recovers as olfactory after lesion. Over the next few days, neurons reappear, but only in those areas in which GBCs are preserved and multiply. In contrast, parts of the epithelium in which GBCs are destroyed are repopulated in part by Bowman's gland cells, which pile up above the basal lamina. Electron microscopy confirms the reciprocity between gland cells and globose basal cells. By 14 days after lesion, the areas that are undergoing metaplasia are repopulated by typical respiratory epithelial cells. As horizontal basal cells are eliminated from all parts of the ventral epithelium, the data suggest that GBC-2(+) cells are ultimately responsible for regenerating olfactory neuroepithelium. In contrast, GLA-13(+) cells may give rise to respiratory metaplastic epithelium where GBCs are eliminated. Thus, we support the idea that a subpopulation of GBCs is the neural stem cell of the olfactory epithelium.

Administration, Inhalation↗