Biomedical subjects

A Sharara

Publications and source records attributed to A Sharara.

2 recordsLinked to original sources

PubMed1998

Bronchoalveolar lavage causes decrease in PaO2, increase in (A-a) gradient value and bronchoconstriction in asthmatics.

The aims of this study were to (1) record the changes of (arterial oxygen partial pressure) PaO2, (arterial carbon dioxide partial pressure) PaCO2, (percentage saturation of haemoglobin with oxygen in arterial blood) SaO2 and alveolar-arterial (A-a) oxygen gradiant resulting from bronchoalveolar lavage (BAL) in asthmatic and normal subjects; (2) measure changes in forced expiratory volume in 1 s (FEV1), vital capacity forced (FVC) associated with BAL; and (3) assess possible predictive factors for the degree of hypoxaemia and impairment of spirometry resulting from BAL. Bronchoscopy and BAL (150 ml) were performed in 24 asthmatics and 15 healthy subjects. Serial arterial blood samples (radial artery) were obtained in all subjects: T1 and before T2 after local anaesthesia; T3 at end of bronchoscopy; T4 after BAL and 5 min, 15 min, 1 h, 2 h, 8 h and 24 h (T5-T10) after the procedure, FEV1 and FVC were measured immediately before and 5 min afer bronchoscopy. Baseline PaO2 was lower in asthmatics (10.2 +/- 0.8 kPa) than in healthy subjects (10.8 +/- 0.8). Both groups showed a significant decrease in PaO2, and a significant widening in (A-a) oxygen tension gradiant at T3-9, with respect to T1 (P < 0.05). PaO2 reached a significantly lower value in asthmatics (7.1 +/- 0.6 kPa) than in HS (7.7 +/- 0.5; P < 0.05). In asthmatics, FEV1, FVC and the ratio FEV1/FVC decreased significantly after BAL (P < 0.001). In healthy subjects, FEV1 and FVC decreased significantly (P < 0.001), whereas FEV1/FVC did not. The fall in FEV1 after BAL was significantly greater in asthmatics (32.4 +/- 10.0%) than in healthy subjects (17.7 +/- 4.6; P < 0.001). Severity of asthma, basline FEV1 or initial PaO2 did not predict the degree of hypoxaemia or the fall of FEV1. It is concluded that BAL causes more severe hypoxaemia and a greater decrease in FEV1 in asthmatics compared to healthy subjects, strongly supporting the recommendation of special caution and careful monitoring when BAL is undertaken in asthmatics.

Analysis of Variance↗

PubMed1997

Induced sputum to assess airway inflammation: a study of reproducibility.

BACKGROUND: Infiltration of the airways mucosa with activated inflammatory cells appears to be a major factor in the pathogenesis of asthma and other airway diseases. Examination of sputum provides a direct method to investigate airway inflammation non-invasively. OBJECTIVES: The aim of the present study was to evaluate the reproducibility of cell counts on cytospins and fluid phase (eosinophil cationic protein, ECP) measurements in a selected portion of induced sputum. We aimed to confirm the validity of the tecnique by comparing measurements between stable asthmatics, allergic rhinithis and healthy subjects. METHODS: Sputum was induced with hypertonic saline (4.5%) twice within one week in 53 stable asthmatics, 16 subjects with seasonal rhinitis (out of the pollen season), and 19 healthy subjects. Reproducibility was examined within sample (two different plugs of the same sample) between sample (two specimens of induced sputum obtained within one week) and between examiners on stable subjects taking into account sample size, number of examinations per patients and Confidence Interval (CI) of the estimates. RESULTS: We have found that the method is highly reproducible within sample and between examiners for all types of cells and fluid phase measurements of ECP. It is reproducible between sample for eosinophils, macrophages, neutrophils and ECP, but not for lymphocytes and weakly for epithelial cells. Sputum from asthmatics, in comparison with the sputum of healthy subjects and subjects with rhinitis had higher eosinophils (asthmatics: 12.2% +/- 12.9, rhinitis: 0.4 +/- 0.8, normals: 0.4 +/- 0.7 (%) and ECP (asthmatics: 827 +/- 491 microg/L, rhinitis: 127 +/- 82 normals: 157 +/- 203). No significant differences were found between healthy subjects and subjects with rhinitis. Eosinophil counts were inversely correlated with FEV1 (r = -0.37) expressed as percentage of predicted, but not significantly correlated with PC20 methacholine (r = -0.28) or blood eosinophils (r = 0.26). CONCLUSIONS: The importance of this study is the confirmation, within important statistical guidelines for a study of reproducibility, that the methods examined are reproducible and valid.

Adult↗