Expiratory time constants by electrical impedance tomography in hypoxemic and hypercapnic acute lung failure - a feasibility study
| Autor: | Wolfram Windisch, Stephan Strassmann, Stephan H. Bohm, Andreas D. Waldmann, Péter L. Róka, Christian Karagiannidis, Ferenc Ender |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
COPD
Expiratory Time ARDS Lung business.industry respiratory system Pulmonary compliance Critical Care and Intensive Care Medicine medicine.disease respiratory tract diseases Pulmonary function testing Airway resistance medicine.anatomical_structure Anesthesia Poster Presentation medicine Lung volumes business |
| Zdroj: | Intensive Care Medicine Experimental |
| ISSN: | 2197-425X |
| Popis: | During relaxed breathing expiration can be compared to a RC-circuit with R being the airway resistance, C the respiratory system compliance and τ = R∙C the expiratory time constant. For the adult respiratory system, the normal τ is around 0.8 s. Different lung pathologies have different time constants. Two common disease types are the acute respiratory distress syndrome (ARDS) and the chronic obstructive pulmonary disease (COPD). ARDS is characterized by stiff or noncompliant lungs with low compliance and normal or lower resistance which results in shorter τ. COPD is characterized by impaired airflow or high airways resistance and high compliance which results higher τ. τ reveals information about respiratory mechanics and the time required for the lungs to empty. Traditional pulmonary function tests provide global information only. EIT is a non-invasive real-time imaging technology which determines changes of lung volumes on a regional basis assuming that local impedance changes are proportional to local changes in lung volume. Pikkemaat [1] introduced the method to calculate regional τ, what we improved and applied in 10 patients. |
| Databáze: | OpenAIRE |
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