Clinical physiology and functional imaging
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Clin Physiol Funct Imaging · Jul 2006
Comparative StudyNasal symptoms, airway obstruction and disease severity in chronic obstructive pulmonary disease.
Chronic obstructive pulmonary disease (COPD) is characterized by inflammation of the lung in association with airflow obstruction. There is increasing evidence of upper airway involvement in COPD and we have reported that this nasal inflammation is proportional to that in the lung. Given recognized relationships between lower airway inflammation and spirometric indices such as the Forced Expiratory Volume in one second (FEV(1)), we hypothesized that there may be a relationship between nasal obstruction and FEV(1) in COPD. We also sought to investigate relationships between nasal symptoms and nasal patency in COPD. ⋯ The degree of nasal airway obstruction in COPD reflects the impairment to pulmonary airflow, and is greater in the presence of chronic nasal symptoms. This study provides further evidence of pan-airway involvement in COPD.
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Clin Physiol Funct Imaging · Jul 2006
Measurement of expired carbon dioxide, oxygen and volume in conjunction with pretest probability estimation as a method to diagnose and exclude pulmonary venous thromboembolism.
The classical alveolar pCO(2)-pO(2) relationship predicts that pulmonary embolism (PE) causes a low ratio of pCO(2)/pO(2) at end expiration. Our purpose was to define a simple protocol to collect expired pCO(2)/pO(2) to diagnose PE. Emergency department patients with suspected PE were enrolled. Clinical pretest probabilities for PE were estimated prior to diagnostic testing using the Canadian score and clinicians' unstructured estimate. Patients provided three 30-s periods of tidal breathing, separated by three deep exhalations. Expired pCO(2), pO(2) and breath volume were measured. All patients underwent standardized objective testing for PE including 90-day follow-up. Diagnosis (PE+) required anticoagulation for image-proven PE within 90 days. ⋯ This preliminary work demonstrates that the end-tidal pCO(2)/pO(2) averaged from 30 s of breathing can produce clinically relevant likelihood ratios for the diagnosis and exclusion of PE.