title: [The significance of maximal expiratory concentrations of CO2 (MEC CO2) in the negative diagnosis of acute pulmonary embolism in chronic obstructive bronchopneumopathies].
abstract: The aim of this prospective study was to analyse the contribution of the measurement of alveolar arterial gradients of CO2 during forced expiration in the diagnosis of pulmonary emboli occurring in chronic airflow obstruction (COPD) as a result of smoking. The study was carried out on 178 patients: Group 1: 54 subjects without emboli (14 controls, 33 COPD and 7 patients with chest pain); Group 2: 72 patients with proved emboli (49 non COPD, 23 COPD); Group 3: 52 patients COPD presenting with varied non-embolic broncho-pulmonary pathology (pneumonia, bronchospasm, pulmonary oedema, bronchial neoplasm). The diagnosis of pulmonary emboli was confirmed by scintigraphy in patients with non COPD or angiography (in patients with COPD). The maximal fraction of CO2 was measured using a capnologue during a forced expiration which was long and prolonged until residual volume was achieved. The PaCO2 was measured simultaneously by an analysis of arterial blood gases. The D index was calculated according to the formula [(PaCO2-PEM CO2)/PaCO2] x 100. The D index was significantly lower in Group 1 (3.42 +/- 3.8% p < 0.0001) than in Group 2 (20.8 +/- 10%) and Group 3 (17.6 +/- 11.7%) (not significant between Groups 2 and 3). In patients with COPD the specificity and sensitivity and the predicted positive and negative value were 100% for a D limit of 7%. In COPD patients these values were respectively 82, 95, 75 and 96% for a D limit of 7%; on the other hand for a D below 5% the values were 60, 100, 64 and 100% respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Clinique de la Louvière, Lille.
authors.forename: J M
authors.initials: JM
authors.lastname: Grosbois
authors.forename: F
authors.initials: F
authors.lastname: Bart
authors.forename: B
authors.initials: B
authors.lastname: Douay
authors.forename: F
authors.initials: F
authors.lastname: Fortin
authors.forename: J M
authors.initials: JM
authors.lastname: Dernis
authors.forename: B
authors.initials: B
authors.lastname: Wallaert
mesh_terms: D000328:Adult; D000368:Aged; D001984:Bronchial Neoplasms / Q000378:metabolism; D001986:Bronchial Spasm / Q000378:metabolism; D002245:Carbon Dioxide / Q000097:blood / Q000378:metabolism*; D002637:Chest Pain / Q000378:metabolism; D005260:Female; D005540:Forced Expiratory Flow Rates; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000150:complications / Q000378:metabolism*; D008297:Male; D008448:Maximal Expiratory Flow Rate; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation; D011014:Pneumonia / Q000378:metabolism; D011446:Prospective Studies; D011654:Pulmonary Edema / Q000378:metabolism; D011655:Pulmonary Embolism / Q000175:diagnosis* / Q000209:etiology; D012115:Residual Volume; D012680:Sensitivity and Specificity; D012907:Smoking / Q000009:adverse effects
chemical_list: D002245:Carbon Dioxide
vernacular_title: Intérêt de la concentration expiratoire maximale de CO2 (CEM CO2) pour le diagnostic négatif de l'embolie pulmonaire aiguë au cours des bronchopneumopathies chroniques obstructives.