Diffusion capacity and CT measures of emphysema and airway wall thickness - relation to arterial oxygen tension in COPD patients.

Background: Decreased diffusing capacity of the lung for carbon monoxide (DLCO) is associated with emphysema. DLCO is also related to decreased arterial oxygen tension (PaO2), but there are limited data on associations between PaO2 and computed tomography (CT) derived measures of emphysema and airway wall thickness.

Objective: To examine whether CT measures of emphysema and airway wall thickness are associated with level of arterial oxygen tension beyond that provided by measurements of diffusion capacity and spirometry.

Serial Measurements of Arterial Oxygen Tension are Associated with Mortality in COPD.

Background: Knowledge on factors associated with mortality can help identify patients with COPD that might benefit from close monitoring and intervention. Arterial blood gases (ABGs) are related to mortality, but both arterial tension of oxygen (PaO2) and arterial tension of carbon dioxide (PaCO2) vary over time. The aim of our study was to investigate the association between repeatedly measured ABGs and mortality in men and women with COPD.

Longterm follow-up in European respiratory health studies - patterns and implications.

Background: Selection bias is a systematic error in epidemiologic studies that may seriously distort true measures of associations between exposure and disease. Observational studies are highly susceptible to selection bias, and researchers should therefore always examine to what extent selection bias may be present in their material and what characterizes the bias in their material. In the present study we examined long-term participation and consequences of loss to follow-up in the studies Respiratory Health in Northern Europe (RHINE), Italian centers of European Community Respiratory Health Survey (I-ECRHS), and the Italian Study on Asthma in Young Adults (ISAYA).

Acetazolamide improves oxygenation in patients with respiratory failure and metabolic alkalosis.

Introduction: Coexistent respiratory failure and metabolic alkalosis is a common finding. Acidotic diuretics cause a fall in pH that may stimulate respiration.

Objective: The purpose of the study was to evaluate the effectiveness of short-term treatment with acetazolamide for combined respiratory failure and metabolic alkalosis.

Explained variance for blood gases in a population with COPD.

Introduction: Variation of blood gas levels in chronic obstructive pulmonary disease (COPD) patients has not been extensively reported and there is limited knowledge about predictors of chronic respiratory failure in COPD patients.

Objectives: The aim of this study was to identify predictors of hypoxemia, hypercapnia and increased alveolar-arterial oxygen difference in COPD patients. We hypothesized that prediction of arterial blood gases will be improved in multivariate models including measurements of lung function, anthropometry and systemic inflammation.