Chronic Obstructive Pulmonary Disease (COPD) (notes) Flashcards
Oxygenation
the process of oxygen diffusing passively from the alveolus to the pulmonary capillary, where it binds to hemoglobin in red blood cells or dissolves into the plasma. Insufficient oxygenation is termed hypoxemia
Oxygen delivery
the rate of oxygen transport from the lungs to the peripheral tissues.
Oxygen consumption
the rate at which oxygen is removed from the blood for use by the tissues.
Oxygen saturation
the percentage of hemoglobin that is bound to oxygen.
Hypoxemia
is defined as an abnormally low level of oxygen in the blood – PaO2 on an ABG
Ventilation
The exchange of air between the lungs and the atmosphere so that oxygen can be exchanged for carbon dioxide in the alveoli
Gas exchange
involves delivering oxygen to the tissues through the bloodstream and expelling wastes and gases, such as carbon dioxide, during expiration. The respiratory system depends on the cardiovascular system for perfusion, or blood flow through the pulmonary system.
COPD- Chronic obstructive pulmonary disease
Preventable and treatable; includes diseases that cause airflow obstruction
Chronic bronchitis
- Defined as the presence of cough and sputum production for atleast 3 months in each of 2 consecutive years.
- The bronchus is narrowed and has impaired airflow due to inflammation, excess mucus production, and potential smooth muscle constriction (bronchospasm).
- Constant irritation causes the mucus-secreting glands and goblet cells to increase in number, leading to increased mucus production which reduces ciliary function.
- The patient is more susceptible to respiratory infections as the alveolar macrophages are altered due to damaged/fibrosed bronchioles.
Emphysema
- Pathological term that describes an abnormal distention of the airspaces beyond the terminal bronchioles and destruction of the walls of the alveoli.
- Progresses slowly over years.
- As the walls of the alveoli are destroyed, the alveolar surface area in direct contact with the pulmonary capillaries continually decrease.
- Leads to dead space and impaired oxygen diffusion – leading to hypoxemia. Impaired oxygen and CO2 exchange results from destruction of the walls of over distended alveoli
COPD Risk factors
- primary smoking
- secondary smoking
- Increased age
- Occupational exposure – dust, chemicals
- Indoor and outdoor pollution
- Genetic abnormalities – including a deficiency of alpha₁ antitrypsin, an enzyme inhibitor that normally counteracts the destruction of lung tissue by certain other enzymes
Emphysema Signs & Symptoms
- Anorexia with weight loss
- Crackles and wheezing on inspiration
- Hyper-resonance
- Malaise
- Mental status changes with increased CO2
- Accessory muscle use for breathing
- Barrel chest
- Chronic cough with or without sputum production
- Clubbed fingers or toes
- Decreased breath sounds
- Decreased chest expansion
- Decreased tactile fremitus
- Dyspnea of exertion
- Tachypnea
Chronic bronchitis Signs & symptoms
- Cor pulmonale and peripheral edema
- Polycythemia
- Prolonged expiration
- Thick copious mucus production
- Weight gain
- ## cyanosis-
- Accessory muscle use for breathing
- Barrel chest possible
- Chronic cough with or without sputum production
- Clubbed fingers and toes
- Decreased breath sounds
- Decreased chest expansion
- Decreased tactile fremitus
- Dyspnea on exertion
- Tachypnea
What questions will you ask when taking a history?
- Risk factors?
- Smoking?
- PMH for allergies, nasal polyps,
- Eating and sleeping habits?
- Quality of life?
- Comorbidities present
- What medications. Do they help?
COPD Assessment
- What position are they sitting in?
- Pulse, Respiratory rate
- Character of respirations
- Accessory muscle use
- Prolonged exhaling?
- Central cyanosis
- Peripheral edema?
- Coughing?
- Clubbing of the fingers?
- Breath sounds – clear, diminished, distant, wheezes
