Module Master 5

Respiratory System Primary Functions

Deliver oxygen to body cells and remove carbon dioxide from the body.

Upper Respiratory Tract (URT) Structures

Includes the nose and nasopharynx down to the larynx.

Lower Respiratory Tract (LRT) Structures

Includes the trachea, bronchial tree, and lungs.

Alveoli Function

Site of gas exchange where oxygen diffuses into the blood and carbon dioxide diffuses out.

Gas Exchange Process

Oxygen diffuses across the alveoli into the bloodstream while carbon dioxide diffuses from the blood into the alveoli for exhalation.

Asthma Definition

Recurrent, reversible shortness of breath caused by narrowing of the bronchi and bronchioles.

COPD Definition

Chronic obstructive pulmonary disease consisting of emphysema and chronic bronchitis.

COPD Components

Emphysema and chronic bronchitis.

Emphysema Definition

Disease involving inflammation and destruction of the alveoli that causes irreversible lung damage.

Chronic Bronchitis Definition

Chronic inflammation and irritation of the bronchi with increased mucus production.

Common Pathophysiology of Asthma and COPD

Both obstruct airflow through the airways.

Chemical Mediators Definition

Substances released from mast cells and white blood cells during inflammation and allergic reactions.

Leukotrienes Function

Cause bronchoconstriction, edema, and inflammation and contribute to asthma symptoms.

Asthma Pathophysiology

Bronchospasm, inflammation, edema, and mucus production narrow the airways and obstruct airflow.

Asthma Types

Allergic asthma is triggered by allergens; intrinsic asthma is caused by unknown factors.

Common Asthma Triggers

Respiratory infections, stress, and cold weather.

Emphysema Pathophysiology

Destruction of alveolar walls decreases surface area for gas exchange and causes hyperinflation.

Hyperinflation Definition

Enlargement of air spaces that makes it difficult to expel air from the lungs.

Causes of Emphysema Progression

Air pollution, tobacco smoke, and other respiratory irritants increase inflammation that damages alveolar walls.

Chronic Bronchitis Pathophysiology

Chronic irritation increases thick mucus production that interferes with gas exchange.

Common Manifestations of Chronic Bronchitis

Chronic cough, difficulty breathing, and increased respiratory infections.

Bronchodilators Mechanism

Relax bronchial smooth muscle to dilate the airways and improve airflow.

Anti-inflammatory Respiratory Drugs Purpose

Reduce airway inflammation so bronchodilators work more effectively.

Primary Bronchodilator Drug Classes

Beta-adrenergic agonists, anticholinergics, and xanthines.

Primary Anti-inflammatory Respiratory Drug Classes

Inhaled corticosteroids (ICS) and leukotriene inhibitors.

Beta-Adrenergic Agonists (Bronchodilators) MOA

Stimulate β₂ receptors in the lungs, activating adenylate cyclase to increase cAMP, relax bronchial smooth muscle, and produce bronchodilation.

Beta-Adrenergic Agonists (Bronchodilators) Primary Uses

Used to treat asthma and COPD by improving airflow through bronchodilation.

Beta-Adrenergic Agonists (Bronchodilators) Adverse Effects

Skeletal muscle tremors and increased heart rate.

β₁ vs β₂ Receptor Locations

β₁ receptors are primarily located in the heart, while β₂ receptors are primarily located in the smooth muscle of the lungs.

cAMP Function in Bronchodilation

Increased cAMP relaxes bronchial smooth muscle, producing bronchodilation.

SABA vs LABA

SABA provides rapid bronchodilation for rescue therapy, while LABA provides prolonged bronchodilation for long-term control and should not be used during acute attacks.

Albuterol (Short-Acting β₂ Agonist [SABA]) Uses

Rescue medication for rapid relief of acute bronchoconstriction in asthma and COPD.

Levalbuterol (Short-Acting β₂ Agonist [SABA]) Uses

Rescue medication for rapid relief of acute bronchoconstriction in asthma and COPD.

Salmeterol (Long-Acting β₂ Agonist [LABA]) Uses

Long-term controller medication for asthma and COPD; not used during emergencies.

Formoterol (Long-Acting β₂ Agonist [LABA]) Uses

Long-term controller medication for asthma and COPD; not used during emergencies.

Anticholinergics (Bronchodilators) MOA

Block acetylcholine receptors, preventing bronchoconstriction and reducing mucus secretion to produce bronchodilation.

Acetylcholine Effects in the Lungs

Causes bronchoconstriction and increased mucus secretion.

Anticholinergics (Bronchodilators) Primary Uses

First-line bronchodilator therapy for COPD and used in asthma when additional bronchodilation is needed or other options cannot be used.

Anticholinergics (Bronchodilators) Adverse Effects

Excessive drying of the mouth and upper respiratory passages.

Ipratropium (Short-Acting Anticholinergic) Uses

Prevention of bronchospasm associated with COPD and additional bronchodilation in asthma when needed.

Tiotropium (Long-Acting Anticholinergic) Uses

Long-term prevention of bronchospasm associated with COPD.

Xanthine Bronchodilators MOA

Inhibit phosphodiesterase (PDE), increasing cAMP to relax bronchial smooth muscle and produce bronchodilation.

Phosphodiesterase (PDE) Function

Inactivates cAMP.

Theophylline (Xanthine Bronchodilator) Uses

Long-term prevention of asthma and COPD symptoms; not used for immediate relief because of its slow onset.

Theophylline (Xanthine Bronchodilator) Additional Effects

Decreases specific chemical mediators, including histamine, involved in allergic reactions.

Theophylline (Xanthine Bronchodilator) Adverse Effects

Nausea, vomiting, anorexia, increased heart rate, palpitations, dysrhythmias, increased urination, and increased blood glucose.

Bronchodilator Classes Comparison

β₂ agonists stimulate β₂ receptors, anticholinergics block acetylcholine receptors, and xanthines inhibit phosphodiesterase to increase cAMP.

Bronchodilator Route of Administration

Beta agonists and anticholinergics are commonly administered by inhaler or nebulizer, while theophylline is administered orally.

Reason Inhaled Bronchodilators Have Few Systemic Side Effects

They deliver medication directly to the lungs with minimal systemic absorption.

Long-Term Controller vs Rescue Medications

Rescue medications rapidly relieve acute bronchoconstriction, while controller medications prevent symptoms and maintain long-term disease control.

Inhaled Corticosteroids (ICS) MOA

Stabilize cell membranes, inhibit inflammatory mediators and allergic antibody production, inhibit arachidonic acid activation, and enhance the activity of beta agonists.

Inhaled Corticosteroids (ICS) Primary Uses

Long-term control of persistent asthma and treatment of COPD.

Inhaled Corticosteroids (ICS) Role in Acute Asthma

Not used for acute asthma attacks; systemic corticosteroids are used during acute attacks.

Inhaled Corticosteroids (ICS) Advantages

Inhalation provides chronic control while minimizing systemic side effects.

Inhaled Corticosteroids (ICS) Adverse Effects

Oral thrush and vocal cord disturbances.

Inhaled Corticosteroids (ICS) Patient Teaching

Rinse the mouth after each use to reduce the risk of oral thrush.

Fluticasone (Inhaled Corticosteroid) Uses

Inhaled corticosteroid used for long-term control of asthma and treatment of COPD.

Beclomethasone (Inhaled Corticosteroid) Uses

Inhaled corticosteroid used for long-term control of asthma and treatment of COPD.

Budesonide (Inhaled Corticosteroid) Uses

Inhaled corticosteroid used for long-term control of asthma and treatment of COPD.

Triamcinolone (Inhaled Corticosteroid) Uses

Inhaled corticosteroid used for long-term control of asthma and treatment of COPD.

Mometasone (Inhaled Corticosteroid) Uses

Inhaled corticosteroid used for long-term control of asthma and treatment of COPD.

Leukotriene Inhibitors MOA

Reduce leukotriene activity by either inhibiting leukotriene synthesis or blocking leukotriene-1 receptors.

Leukotriene Inhibitors Primary Uses

Asthma prophylaxis and chronic maintenance; not for acute asthma attacks.

Leukotriene Inhibitors Therapeutic Effects

Reduce bronchoconstriction, mucus production, and inflammation.

Zileuton (Leukotriene Inhibitor) MOA

Inhibits the enzyme required for leukotriene synthesis.

Montelukast (Leukotriene Inhibitor) MOA

Blocks the leukotriene-1 receptor.

Zafirlukast (Leukotriene Inhibitor) MOA

Blocks the leukotriene-1 receptor.

Zileuton (Leukotriene Inhibitor) Adverse Effects

Headache, nausea, dizziness, and insomnia.

Montelukast & Zafirlukast (Leukotriene Inhibitors) Adverse Effects

Headache, nausea, and diarrhea.

Respiratory Anti-inflammatory Drug Classes Comparison

Inhaled corticosteroids broadly suppress airway inflammation, while leukotriene inhibitors specifically block leukotriene-mediated inflammation.

Metered-Dose Inhaler (MDI) Characteristics

Pressurized canister that delivers a reliable, consistent dose of medication as an aerosolized mist.

Dry Powder Inhaler (DPI) Characteristics

Breath-activated device that releases powdered medication only when the patient takes a deep, fast breath.

Nebulizer Characteristics

Uses a machine to convert liquid medication into a fine mist that is inhaled through a mask.

Nebulizer Advantages

Useful for pediatric and elderly patients who may not have the dexterity required to use an inhaler.

Respiratory Medication Delivery Device Comparison

MDIs use a pressurized aerosol, DPIs require a deep, fast inhalation to activate the medication, and nebulizers continuously deliver a fine mist through a mask.

Metered-Dose Inhaler (MDI) Administration Steps

Shake the inhaler, exhale completely, begin inhaling while pressing the canister, continue a slow deep breath, hold the breath for about 10 seconds, then exhale slowly.

Dry Powder Inhaler (DPI) Administration Steps

Open/load the inhaler, exhale away from the device, inhale deeply and quickly through the mouthpiece, hold the breath for about 10 seconds, then exhale slowly and close the inhaler.

Common Medications Available as Metered-Dose Inhalers (MDIs)

Albuterol (Ventolin), ipratropium (Atrovent), and fluticasone (Flovent).

Common Medications Available as Dry Powder Inhalers (DPIs)

Salmeterol (Serevent Diskus), fluticasone (Flovent Diskus), mometasone (Asmanex Twisthaler), and tiotropium (Spiriva HandiHaler).

Common Medications Available as Nebulizer Solutions

Albuterol and ipratropium.

Intermittent Asthma Preferred Treatment

SABA used as needed.

Persistent Asthma Stepwise Treatment

Progress from low-dose ICS to higher-dose ICS and/or addition of a LABA as disease severity increases.

Severe Persistent Asthma Treatment

High-dose ICS + LABA + oral corticosteroid.

Quick-Relief Medication for Asthma

A SABA should always be used as needed for symptoms of shortness of breath.

Indicator That Asthma Therapy Should Be Stepped Up

Needing a SABA more than 2 days per week indicates inadequate asthma control.

COPD Long-Term Controller Therapy

Centers on long-acting β₂ agonists (LABAs) and long-acting anticholinergics.

Role of Inhaled Corticosteroids (ICS) in COPD

Used in combination with a LABA or long-acting anticholinergic; not recommended as monotherapy.

Role of SABA in COPD

Should not be relied upon for regular long-term symptom control.

Asthma vs COPD Drug Therapy

Asthma treatment follows a stepwise approach beginning with SABA and escalating controller therapy, while COPD treatment centers on LABAs and long-acting anticholinergics.

Asthma vs COPD Pathophysiology

Asthma causes reversible airway narrowing from bronchospasm and inflammation, while COPD causes persistent airflow obstruction from emphysema and chronic bronchitis.

Emphysema vs Chronic Bronchitis

Emphysema destroys alveolar walls and reduces gas-exchange surface area, while chronic bronchitis causes chronic bronchial inflammation with excessive mucus production.

Bronchodilators vs Anti-inflammatory Respiratory Drugs

Bronchodilators improve airflow by relaxing airway smooth muscle, while anti-inflammatory drugs reduce airway inflammation and improve long-term disease control.

Metered-Dose Inhaler (MDI) vs Dry Powder Inhaler (DPI)

MDIs deliver medication as a pressurized aerosol, whereas DPIs are breath-activated and require a deep, rapid inhalation.

Problem Set: Three Bronchodilator Classes and Their MOAs

Beta agonists stimulate β₂ receptors to increase cAMP, anticholinergics block acetylcholine receptors, and xanthines inhibit phosphodiesterase to increase cAMP.

Problem Set: Anti-inflammatory Respiratory Drug Classes

Inhaled corticosteroids (ICS) and leukotriene inhibitors.

Systemic vs Inhaled Corticosteroids

Systemic corticosteroids are used during acute asthma attacks and have more systemic adverse effects, whereas inhaled corticosteroids are preferred for chronic control because they minimize systemic adverse effects.

Leukotriene Inhibitors Subclasses

Zileuton inhibits leukotriene synthesis, while montelukast and zafirlukast block leukotriene-1 receptors.

Dry Powder Inhaler (DPI) Patient Teaching

Open/load the inhaler, exhale away from the device, inhale deeply and quickly through the mouthpiece to activate the medication, hold your breath for about 10 seconds, then exhale slowly.

Metered-Dose Inhaler (MDI) Patient Teaching

Shake the inhaler, exhale completely, begin a slow deep inhalation while pressing the canister once, continue inhaling deeply, hold your breath for about 10 seconds, then exhale slowly.

SABA Definition

Short-acting beta agonist.