Asthma: Pathophysiology, GINA Management, and Nursing Care

Asthma is one of the most commonly tested respiratory conditions on the NCLEX. This note reviews its pathophysiology, triggers, clinical presentation, diagnostic workup, GINA stepwise treatment, acute exacerbation management, and the nursing priorities that distinguish safe care from a missed life-threatening event.

What Is Asthma?

• A chronic inflammatory disease of the airways characterized by reversible airflow obstruction and airway hyperresponsiveness.
• Inflammation produces bronchoconstriction, mucus production, and airway edema.
• The key feature distinguishing asthma from COPD: airflow obstruction is reversible with bronchodilators.

Pathophysiology

• Inflammatory cells infiltrate airway walls, causing swelling, edema, and narrowing.
• Smooth muscle contraction around airways causes wheezing, chest tightness, and dyspnea.
• Increased mucus production with mucus plugging causes cough and airflow obstruction.
• Chronic inflammation can lead to airway remodeling with irreversible changes.
• Obstruction is most pronounced on expiration, leading to air trapping.
• In life-threatening asthma, the chest may become silent because air cannot move.

Common Triggers

• Allergens: pollen, dust mites, pet dander, mold.
• Environmental: tobacco smoke, air pollution, chemical fumes.
• Respiratory infections, especially viral URIs.
• Exercise (exercise-induced bronchoconstriction).
• Medications: aspirin, beta-blockers, NSAIDs.
• Other: cold air, GERD, emotional stress, obesity.

Clinical Presentation

Symptoms

• Wheezing: high-pitched whistling sound on expiration.
• Dyspnea: shortness of breath, especially with exertion or at night.
• Cough: often worse at night; may be the only symptom in cough-variant asthma.
• Chest tightness: sensation of pressure or constriction.

Signs on Examination

• Tachypnea with increased respiratory rate.
• Tachycardia from stress and beta-agonist medications.
• Prolonged expiration and accessory muscle use.
• Tripod positioning with hands on knees.
• Bilateral expiratory wheezing on auscultation.
• Fine hand tremor from beta-agonist use.

Life-Threatening Asthma Signs

• Silent chest — no air movement.
• Inability to speak in full sentences.
• Cyanosis.
• Confusion, drowsiness, or exhaustion.
• Bradycardia as a late sign.
• Hypotension and SpO₂ < 92%.
• Peak flow < 33% of personal best.

Mnemonic — SILENT: Silent chest, Inability to speak, Low O₂, Exhaustion, Not improving, Tachycardia turning to bradycardia.

Diagnostic Tests

• Spirometry (gold standard): FEV1/FVC ratio < 0.70; ≥ 12% improvement in FEV1 after bronchodilator confirms reversible obstruction.
• Peak flow: monitors severity and response; compared to personal best using zones. Red zone < 50% = emergency.
• Pulse oximetry: SpO₂ < 92% indicates a severe attack; monitor continuously during exacerbation.
• Chest X-ray: may show hyperinflation or be normal; rules out pneumonia or pneumothorax.

Acute Exacerbation Management — OSHIT

• O – Oxygen: give immediately to maintain SpO₂ 94–98%; use high-flow if severely hypoxic.
• S – SABA: inhaled albuterol via nebulizer or MDI is first-line for acute bronchospasm.
• H – Hydrocortisone: IV systemic corticosteroid to reduce inflammation in severe exacerbations.
• I – Ipratropium: added to SABA in severe cases for synergistic bronchodilation.
• T – Theophylline: IV bronchodilator used in life-threatening asthma not responding to other treatments.

GINA Stepwise Approach

Track 1 (preferred) — ICS-formoterol as both controller and reliever

• Step 1: As-needed low-dose ICS-formoterol.
• Step 2: As-needed low-dose ICS-formoterol.
• Step 3: Low-dose ICS-formoterol maintenance + as-needed reliever (MART regimen).
• Step 4: Medium-dose ICS-formoterol maintenance + as-needed reliever.
• Step 5: Add LAMA; consider biologics for severe persistent asthma.

Track 2 (alternative) — ICS daily + SABA PRN

• Step 1: Take ICS whenever SABA is used.
• Step 2: Low-dose ICS daily + SABA PRN.
• Step 3: Low-dose ICS-LABA + SABA PRN.
• Step 4: Medium-dose ICS-LABA + SABA PRN.
• Step 5: Add LAMA; consider biologics.

Key point: SABA-only therapy is no longer recommended for adults and adolescents.

Inhaler Technique

Metered-Dose Inhaler (MDI):

• Shake well and exhale fully.
• Place mouthpiece between teeth and seal lips.
• Begin slow inhalation and press canister once.
• Continue slow, deep breath; hold for 10 seconds.
• Wait 30–60 seconds between puffs.
• Use a spacer when possible for better drug delivery: one puff into spacer, then inhale slowly and deeply.
• Rinse mouth after ICS use to prevent thrush and hoarseness.

Dry Powder Inhaler (DPI):

• Do not shake; load dose and exhale away from device.
• Inhale rapidly and deeply, then hold breath for 10 seconds.

Nursing Care

• Monitor respiratory rate, depth, and effort continuously.
• Auscultate lung sounds for wheezing or diminished sounds.
• Assess oxygen saturation and titrate oxygen to target range.
• Monitor peak flow before and after treatments.
• Assess for accessory muscle use and retractions.
• Position in high-Fowler's to facilitate breathing.
• Administer medications on time; monitor for side effects (tachycardia, tremor).
• Stay with the patient during acute exacerbations.
• Provide emotional support to reduce anxiety.
• Ensure adequate hydration and document all assessments.

Patient Teaching

• Use bronchodilators first, then ICS.
• Rinse mouth after ICS to prevent thrush.
• Know the difference between rescue and maintenance inhalers.
• Use a spacer with MDIs for better delivery.
• Never run out of the rescue inhaler.
• Avoid tobacco smoke and environmental irritants.
• Control dust mites with allergen-proof covers.
• Manage GERD if present.
• Get the annual flu vaccine.
• Use a peak flow meter daily and record readings.
• Recognize early warning signs of exacerbation.
• Follow a personalized asthma action plan.
• Seek help if no relief from rescue inhaler or peak flow < 50%.

Common NCLEX Traps

• SABA-only treatment is no longer recommended for adults and adolescents.
• LABAs should never be used as monotherapy — always combined with ICS.
• Rinsing mouth after ICS prevents oral thrush.
• Silent chest signals life-threatening asthma, not improvement.
• High-dose albuterol can cause hypokalemia.
• Peak flow < 50% = red zone emergency.
• Theophylline therapeutic range: 10–20 mcg/mL.
• Montelukast is for maintenance, not acute attacks.
• Asthma is reversible; COPD is not — a key distinguishing feature.

Key Takeaways

• Asthma is a chronic inflammatory disease with reversible airflow obstruction; reversibility distinguishes it from COPD.
• Diagnose with spirometry: FEV1/FVC < 0.70 and ≥ 12% reversibility after bronchodilator.
• GINA now favors ICS-formoterol (Track 1) for both control and relief; SABA-only therapy is out.
• Manage acute exacerbations with the OSHIT approach: Oxygen, SABA, Hydrocortisone, Ipratropium, Theophylline.
• Recognize life-threatening signs: silent chest, cyanosis, bradycardia, exhaustion, SpO₂ < 92%, peak flow < 33%.
• Core teaching: correct inhaler technique, rinse mouth after ICS, never run out of the rescue inhaler, and follow a written asthma action plan.