00:00 / 00:00
Acute respiratory distress syndrome
Pulmonary changes at high altitude and altitude sickness
Congenital pulmonary airway malformation
Superior vena cava syndrome
Apnea of prematurity
Meconium aspiration syndrome
Neonatal respiratory distress syndrome
Sudden infant death syndrome
Transient tachypnea of the newborn
Alpha 1-antitrypsin deficiency
Idiopathic pulmonary fibrosis
Restrictive lung diseases
Apnea, hypoventilation and pulmonary hypertension: Pathology review
Cystic fibrosis: Pathology review
Deep vein thrombosis and pulmonary embolism: Pathology review
Lung cancer and mesothelioma: Pathology review
Obstructive lung diseases: Pathology review
Pleural effusion, pneumothorax, hemothorax and atelectasis: Pathology review
Pneumonia: Pathology review
Respiratory distress syndrome: Pathology review
Restrictive lung diseases: Pathology review
Tuberculosis: Pathology review
0 / 14 complete
0 / 5 complete
croup p. 167
cystic fibrosis p. 58
Haemophilus influenzae p. , 140
bronchitis p. 698
bronchitis and p. 698
Bronchitis means inflammation of the bronchial tubes in the lung, and it’s said to be chronic when it causes a productive cough—which means produces mucus—for at least 3 months each year for 2 or more years.
These two are different in that chronic bronchitis is defined by clinical features, like a productive cough, whereas emphysema is defined by structural changes—specifically enlargement of the air spaces.
That being said, they often coexist, probably because they share the same major risk factor — smoking.
Other risk factors for chronic bronchitis include exposure to air pollutants like sulfur and nitrogen dioxide, exposure to dust and silica, as well as genetic factors like having a family history of chronic bronchitis.
With COPD, the airways become obstructed, and the lungs don’t empty properly, and that leaves air trapped inside the lungs.
This reduction is especially noticeable in the first second of air breathed out in a single breath, called FEV1—forced expiratory volume (in one second), which typically is reduced even more than the FVC.
A useful metric therefore is the FEV1 to FVC ratio, which, since the FEV1 goes down even more than FVC, causes the FEV1 to FVC ratio to go down as well.
Alright so say normally your FVC is 5 L, and your FEV1 is 4 L, your FEV1 to FVC ratio would end up being 80%.
Now, someone with COPD’s FVC might be 4 L instead, which is lower than normal, but the volume of air that he or she can expire in the first second is only 2 L, so not only are both these values lower, but their ratio is lower as well—and this is a hallmark of COPD.
All that had to do with air breathed out right? Conversely, for air going in, the TLC, or total lung capacity, which is the maximum volume of air that can be taken in or inspired into the lungs, is actually often often higher because of the air trapping.
Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Cookies are used by this site.
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.