Respiratory System: Disorders of Ventilation and Gas Exchange Flashcards
define four lung volumes: tidal volume, inspiratory reserve volume, expiratory reserve volume, residual volume
tidal volume: volume of air inspired (or exhaled) with each breath
inspiratory reserve volume: the maximum amount of air that can be inspired in excess of the normal VT (tidal volume)
expiratory reserve volume: the maximum amount of air that can be exhaled in excess of normal VT (tidal volume)
residual volume is the approixmately 1200ml of air that always remains in the lungs after forced expiration
define dead space and lung compliance
Anatomic dead space specifically refers to the volume of air located in the respiratory tract segments that are responsible for conducting air to the alveoli and respiratory bronchioles but do not take part in the process of gas exchange itself.
lung compliance refers to the ease with which the lungs can be inflated.
briefly define ventilation perfusion mismatch, including at least one disease process for V>P, or P>V
ventilation/perfusion mismatch is when there is an inequality in either the ventilation or the perfusion in a patient. The gas exchange properties in the lungs depend on matching ventilation and perfusion.
disease V>P—> bronchitits
disease P>V—> COPD, asthma
describe pulmonary function testing
Pulmonary function tests (PFTs) are noninvasive tests that show how well the lungs are working. The tests measure lung volume, capacity, rates of flow, and gas exchange. The person blows into a machine and the machine helps the provider measure the above aspects.
contrast acute bronchitis from chronic bronchitis.
acute bronchitis is short term and resolves within a couple of weeks. Can be seen in children or any population, really.
chronic bronchitis is seen most commonly in middle aged men and is associated with chronic irritation from smoking and recurrent infections. a diagnosis requires the history of a chronic productive cough for at least 3 consecutive months in at least two years.
describe the major differences between the pink puffers and blue bloaters, knowing that in real life, these conditions usually coexist.
pink puffers: people with predominant emphysema, referred to pink puffers because of the lack of cyanosis, the use of accessory muscles, and pursed lip (puffer) breathing.
blue bloaters: people with a clinical syndrome of chronic bronchitis, cyanosis and fluid retention associated with right sided heart failure.
compare and contrast emphysema and bronchitis in the following areas: pathogenesis, pathology, and symptoms.
pathogenesis-emphysema: breakdown of elastin and other alveolar wall components by enzymes.
bronchitis: overproduction and hypersecretion of mucus by goblet cells.
pathology: muscus gland hyperplasia (as seen in the images below) is the histologic hallmark of chronic bronchitis. Airway structural changes include atrophy, focal squamous metaplasia, ciliary abnormalities, variable amounts of airway smooth muscle hyperplasia, inflammation, and bronchial wall thickening.
pathology chronic bronchitis: The pathology of chronic bronchitis includes an inflammatory mononuclear cell infiltrate in the airway wall and a neutrophil influx into the airway lumen.
compare and contrast in emphsyema and chronic bronchitis in the following area: symptoms
symptoms emphysema:
Shortness of breath, especially during light exercise or climbing steps.
Ongoing feeling of not being able to get enough air.
Long-term cough or “smoker’s cough”
Wheezing.
Long-term mucus production.
Ongoing fatigue.
symptoms: chronic bronchitis: Cough, often called smoker's cough. Coughing up mucus (expectoration) Wheezing. Chest discomfort.
how does alpha one antitrypsin refer to the pathogenesis of emphysema?
AAT is an enzyme that protects the lungs from injury. With emphysema, there is no protection and so injury can happen more frequently.
explain why polycythemia occurs with COPD. hint: related to underlying hypoxia
because of the underlying hypoxia, the body thinks that there is not enough red blood cells and stimulates RBC production, (but immature cells) causing polycythemia.
describe the use of oxygen in COPD.
oxygen therapy is prescribed for people with significant hypoxemia (aterial PO less that 55 mmhg). Administration of continous low-flow (1-2 L/minute) oxygen to maintain aterial PO levels between 55 and 65 mmhg decreases dyspena and pulmonary hypertension, along with improving neurophysiologic function and activity tolerance.
discuss the difference (from normal) in the breathing pattern and work of breathing in COPD.
in COPD, the breathing becomes more labored, and because there is less perfusion, more breaths need to be taken to get adequate air supply.
what are clinical signs, diagnosis, and treatment for acute bronchitis?
clinical signs: Coughing with or without mucus, soreness in the chest, Feeling tired (fatigue), Mild headache, Mild body aches
Sore throat.
diagnosis: blood tests, physical exam, pulse ox, cultures of nasal discharge, etc.
treatment: drink fluids, OTC meds to help with pain, wait it out.
in spirometry, describe the FEV 1/FVC ratio.
The FEV1/FVC is a ratio that reflects the amount of air you can forcefully exhale from your lungs. This ratio is often used in diagnosing and monitoring the treatment of lung diseases such as chronic obstructive pulmonary disease (COPD).
normal ratio: 70% to 80%, anything below 70% could indicate COPD and airway limitation.
