Pulmonary-Function Tests
| Autor: | George L. Kemp |
|---|---|
| Rok vydání: | 1969 |
| Předmět: |
business.industry
Dead space General Medicine Carbon Dioxide respiratory system Alveolar hypoventilation Alveolar–arterial gradient Respiratory Function Tests Hypoxemia Pulmonary function testing Pulmonary Alveoli Anesthesia Hyperventilation cardiovascular system Breathing medicine Humans medicine.symptom Pulmonary Embolism business Perfusion circulatory and respiratory physiology |
| Zdroj: | JAMA: The Journal of the American Medical Association. 207:2105 |
| ISSN: | 0098-7484 |
| DOI: | 10.1001/jama.1969.03150240125033 |
| Popis: | To the Editor:— The article "Pulmonary-Function Tests" which appeared inThe Journal( 206 :2302, 1968) contains the following statement: "The level of arterial Pco 2 is governed solely by the alveolar ventilation. Elevated Pco 2 means alveolar hypoventilation, and reduced Pco 2 , alveolar hyperventilation." Such a statement ignores the ventilation to perfusion relationship in which a reduction in perfusion may commonly increase functional dead space, shuntlike effects, hypoxemia, and finally CO 2 retention. Ventilation-perfusion problems must be distinguished from alveolar hypoventilation, which caused decreased alveolar Po 2 together with increased arterial Pco 2 . While it is true that a diffusion barrier for CO 2 is for practical purposes almost nonexistent as compared to O 2 , the perfusion of alveoli has an important role in relationship to CO 2 elimination. This fact has clinical importance in the evaluation of pulmonary emboli in which the alveolar Pco 2 levels may be reduced |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|