Respiratory Pharmacology: Asthma Management

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Questions and Answers

What are common triggers for extrinsic asthma?

Pollen and pet dander (correct)

Respiratory infections

Exercise and smoke

Cold air and stress

What role do IgE antibodies play in extrinsic asthma?

They trigger an immune response to allergens (correct)

They create mucus in the airways

They help oxygenate blood

They suppress inflammation

Which symptom is commonly associated with an early phase response of extrinsic asthma?

Chest tightness (correct)

Epithelial cell injury

Increased mucus production

Heightened airway responsiveness

What characterizes the late phase response in extrinsic asthma?

Recruitment of additional inflammatory cells Signup and view all the answers

Which of the following is NOT a characteristic of intrinsic asthma?

Caused by allergens like pollen Signup and view all the answers

What physiological change occurs during a viral respiratory infection related to intrinsic asthma?

Damage to epithelial cells Signup and view all the answers

Which symptom could indicate a late phase response of extrinsic asthma?

Shortness of breath Signup and view all the answers

Which mediators are released during an extrinsic asthma early phase response?

Histamine and leukotrienes Signup and view all the answers

What is primarily responsible for the activation of mast cells during an allergic response?

Cross-linking of IgE antibodies Signup and view all the answers

Which mediators are released by mast cells during degranulation?

Histamine, leukotrienes, and prostaglandins Signup and view all the answers

What effect does the activation of eosinophils have on the airway epithelium?

It damages the airway epithelium Signup and view all the answers

What is airway remodeling in the context of chronic asthma?

Structural changes leading to thickened airway walls Signup and view all the answers

Which of the following most accurately describes extrinsic asthma?

Often correlates with a family history and allergic disorders Signup and view all the answers

What is a common feature of both intrinsic and extrinsic asthma?

Involves airway inflammation Signup and view all the answers

What is the primary role of Beta 2 adrenergic receptors in airway physiology?

Increase bronchodilation Signup and view all the answers

Which statement accurately describes the role of the parasympathetic nervous system in airway function?

It causes continuous bronchoconstriction Signup and view all the answers

How do prostaglandins contribute to the symptoms of asthma?

By promoting bronchoconstriction Signup and view all the answers

What is a common clinical presentation in a patient experiencing an asthma attack?

Increased respiratory rate and wheezing Signup and view all the answers

What is one of the consequences of chronic inflammation in asthma?

Development of fibrosis and airway remodeling Signup and view all the answers

How does inflammatory mediators contribute to bronchoconstriction?

They are released by mast cells and promote inflammation Signup and view all the answers

What is the difference between asthma and status asthmaticus?

Status asthmaticus involves a prolonged, severe asthma attack that doesn’t respond to treatment Signup and view all the answers

Which medication class is primarily used to facilitate airway dilation during an asthma attack?

Beta 2 agonists Signup and view all the answers

How does end tidal monitoring assist in assessing asthma patients?

It helps detect carbon dioxide levels in exhalation Signup and view all the answers

Which of the following is NOT a common asthma trigger?

High humidity levels Signup and view all the answers

Study Notes

Topic/Respiratory Pharmacology

Topic: Pathophysiology and management of reactive airway disease
Objectives:
- Review airway physiology
- Explain the inflammatory process and how it contributes to bronchoconstriction
- List asthma triggers
- Describe the clinical presentation of an asthma patient
- Explain how end tidal monitoring is beneficial in monitoring a patient suffering from an asthma attack
- Differentiate between asthma and status asthmaticus
- Explain best evidence-based treatment for asthma including the roles of beta 2 agonists, anticholinergics, steroids, and sympathomimetics
NOCP:
- Conduct respiratory system assessment and interpret findings
- Conduct oximetry testing and interpret findings
- Conduct end tidal carbon dioxide monitoring and interpret findings
- Follow safe process for responsible medication administration
- Administer medication via inhalation
- Provide care to patients experiencing signs & symptoms involving respiratory system

Physiology of Airway Disease – Asthma

Review of Airway Physiology:
- Air moves through upper airways (mouth, nose) into lower airways (trachea, bronchioles, alveoli)
- Trachea and upper bronchi have cartilage, lower airways have smooth muscle allowing for contraction and relaxation
- Alveoli are the site of gas exchange
- Airways are innervated by autonomic nervous system with parasympathetic & sympathetic stimulation
- Normally parasympathetic stimulation (vagus) overrides sympathetic, resulting in a slight bronchoconstriction.
- Exercise increases need for airflow, inhibiting vagal bronchoconstriction and increasing sympathetic bronchodilation

Inflammatory Mediators

Mast cells release chemicals that cause inflammation.
Mast cells are immune cells found in tissues throughout the body, near blood vessels, nerves, skin, lungs, and digestive tract.
- Allergic reactions : Histamine, heparin released in allergic response
- Immune defense; Act as sentinels, detecting and responding to harmful pathogens
- Wound healing and tissue repair : Contribute to wound healing and angiogenesis
- Regulation of blood flow : Release histamine, increasing blood flow in immune responses and healing

Clinical Significance

Mast Cell Activation Syndrome (MCAS): Mast cells release too many chemicals leading to chronic and systemic issues.
Anaphylaxis: Severe, potentially life-threatening reaction involving widespread mast cell activation and histamine release

Key Roles of Mast Cells in Asthma

Release of Mediators: Mast cells release histamine, leukotrienes, prostaglandins causing inflammation, bronchoconstriction, increased mucus
Bronchoconstriction: Histamine, other mediators constrict airway smooth muscles leading to breathing difficulty.
Inflammatory Response: Mast cells contribute to early-phase and late-phase response, allergen exposure, inflammation, and hyperresponsiveness
Recruitment of Other Immune Cells: Mast cells attract other immune cells (eosinophils & T cells) amplifying inflammatory response, contributing to chronic asthma

Asthma - Intrinsic vs. Extrinsic

Extrinsic Asthma (Allergic Asthma):
- Onset in childhood & adolescence
- Family history common
- Often associated with other allergic disorders
- Attacks related to specific allergens (pollen, mold, pet dander, foods)
- Immune response involves IgE antibodies recognizing allergens
- Most common type of asthma (60-90%)

Asthma Symptoms

Wheezing, coughing, chest tightness, difficulty breathing
Attacks can vary from mild to severe episodes
Variation in onset time
Worse at night

Asthma and the Role of ETCO2

Mechanism: Asthma is ventilation problem, not oxygenation
Airway constriction: Prolonged expiration, wheezing, turbulent airflow
Carbon dioxide buildup: Air trapped in alveoli, fatigue, inability to exhale completely
Capnography: Reflects real-time CO2 elimination during exhalation, helping assess severity
ETCO2 levels: Typically 35-45 mmHg; In asthma, it may fall initially as respiratory rate increases to compensate for CO2 overload but then rises with worsening respiratory failure (over 100 mmHg)

Status Asthmaticus

Severe asthma attack unresponsive to standard treatment
Progressive complication, life-threatening
Inflammation and mucosal plugging increase airway hyperreactivity
Symptoms include exhaustion, decreased alertness, hypoxia, cyanosis, absence of breath sounds
Requires aggressive treatment

Beta 2 Agonists

Mechanism: Beta-2 agonists stimulate beta-2 adrenergic receptors in bronchial smooth muscles relaxing them enabling better airflow.
Actions: Bronchodilation, inhibits bronchoconstricting agent release, enhances mucociliary clearance.
Salbutamol (albuterol): Common beta-2 agonist, quick onset of action, often preferred as rescue medication.

Corticosteroids (Dexamethasone)

Mechanism: Decreasing inflammation.
Actions: Enhancing surfactant levels and improving pulmonary circulation

Anticholinergics (Ipratropium Bromide)

Mechanism: Antagonist to muscarinic acetylcholine receptors, inhibiting bronchoconstriction and secretions.
Actions: Slower onset but longer duration of action. Often used as maintenance treatment.

Immunoglobulins (IgE)

Role: Immune response component, antibodies responding to allergens
Clinical relevance: When allergens bind to IgE antibodies on mast cells, it initiates a cascade of inflammation and bronchoconstriction.

Medication Administration: MDI/NEB/IM

Specific medications: salbutamol, epinephrine, dexamethasone
Routes MDI, NEB, & IM
Dosage: Weight-based dosage calculations, and consideration for contraindication
Procedure: Specific step-by-step instructions for each administration method

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Description

This quiz focuses on the pathophysiology and management of reactive airway diseases, particularly asthma. It covers airway physiology, inflammatory processes, common triggers, and the clinical presentation of asthma patients. Additionally, it reviews evidence-based treatments and the benefits of monitoring methods such as end tidal carbon dioxide measurement.