---

Clinical Reference Guide: Bronchial Asthma Management

---

1. Definition and Pathophysiology

• Airway smooth muscle bronchoconstriction
• Mucosal edema from vascular permeability
• Mucus hypersecretion
• Eosinophilic/neutrophilic airway inflammation
• Airway remodeling in chronic disease

---

2. Risk Factors and Triggers

• Fishman's Pulmonary Diseases, p. 799

---

3. Diagnosis

Clinical Features

• Episodic wheezing, dyspnea, chest tightness, cough (often nocturnal)
• Symptoms variable and reversible
• Cough-variant asthma: chronic cough as the sole manifestation, with airway hyperresponsiveness

Spirometry (Key Diagnostic Test)

• FEV1/FVC ratio reduced (obstructive pattern)
• Bronchodilator reversibility: FEV1 improvement ≥12% and ≥200 mL after SABA
• FEV1 - normal between attacks in mild asthma; strong predictor of decline in asthma control at low values
• PEF variability >20% diurnally supports diagnosis

Validated Control Assessment Tools

• Asthma Control Test (ACT)
• Asthma Control Questionnaire (ACQ)
• Asthma Therapy Assessment Questionnaire (ATAQ)

Differential Diagnosis (Before Stepping Up Therapy, Exclude)

• COPD / ACO (asthma-COPD overlap)
• Vocal cord dysfunction / inducible laryngeal obstruction
• GERD-related cough
• Heart failure
• Chronic rhinosinusitis / postnasal drip
• Bronchiectasis

---

4. Classification of Severity (NHLBI, Adults ≥12 years)

• Textbook of Family Medicine 9e, p. 465

GINA Control Classification (for ongoing monitoring)

1. Controlled - step down or maintain therapy
2. Partly controlled - consider stepping up
3. Uncontrolled - step up until symptom control achieved
4. Exacerbation - treat per acute exacerbation algorithms

• Fishman's Pulmonary Diseases, p. 810

---

5. Chronic (Long-Term) Management - Stepwise Approach

GINA Track 1 (Preferred - ICS-Formoterol as Reliever)

GINA Track 2 (Alternative - SABA Reliever)

Key principle: Using ICS-formoterol as reliever (Track 1) reduces exacerbation risk compared with SABA reliever. Check adherence likelihood before choosing Track 2.

• Washington Manual of Medical Therapeutics, p. 331; Murray & Nadel's, p. 1447

Before Stepping Up Therapy - Check for:

1. Non-adherence to ICS (associated with increased exacerbations, lung function decline, hospitalization, death)
2. Incorrect inhaler technique
3. Ongoing allergen/irritant exposure
4. Comorbidities: obesity, sinonasal disease, GERD, OSA, depression
5. Alternative diagnosis

---

6. Pharmacological Agents

6a. Short-Acting Beta-2 Agonists (SABAs)

• Drugs: Albuterol (salbutamol), levalbuterol
• Mechanism: Bind beta-2 receptors → increased intracellular cAMP → airway smooth muscle relaxation; also reduce vascular permeability and inflammatory mediator release
• Onset: Rapid; peak action 60-90 min
• Use: Rescue/reliever therapy; also pre-exercise prophylaxis (5-10 min before)
• Caution: >2 uses/week = sign of inadequate control; overuse → receptor desensitization

6b. Long-Acting Beta-2 Agonists (LABAs)

• Drugs: Salmeterol, formoterol, vilanterol, indacaterol (ultra-LABA)
• Use: Always in combination with ICS for chronic management; NEVER as monotherapy
• Formoterol: Shorter onset - useful both as maintenance and reliever (in ICS-formoterol regimens)
• Benefit: Improve lung function, reduce symptoms, reduce exacerbation frequency

6c. Inhaled Corticosteroids (ICS) - Cornerstone of Treatment

• Drugs: Beclomethasone, budesonide, fluticasone, ciclesonide, mometasone
• Mechanism: Suppress airway inflammation; reduce eosinophilic infiltration; decrease mucus secretion
• Starting dose (low-to-moderate): e.g., beclomethasone 200 µg BID
• Key point: Poor adherence to ICS is the most common modifiable risk factor for exacerbations

6d. Long-Acting Muscarinic Antagonists (LAMAs)

• Drug: Tiotropium
• Use: Add-on at Step 4-5 for inadequately controlled asthma on ICS-LABA
• Benefit: Improves lung function and reduces exacerbations as add-on to ICS-LABA

6e. Leukotriene Modifiers

• Drugs:
  • Montelukast (10 mg/day adults; 4-5 mg children) - LTD4 receptor antagonist
  • Zafirlukast (20 mg BID) - LTD4 receptor antagonist
  • Zileuton (1200 mg SR BID) - 5-lipoxygenase inhibitor
• Mechanism: Block bronchoconstriction, mucosal edema, mucus hypersecretion mediated by cysteinyl leukotrienes
• Special indication: Aspirin-exacerbated respiratory disease (AERD) - occurs in ~5-10% of asthmatics
• Note: Less effective than ICS alone but orally administered; approved for children (montelukast from 12 months)

6f. Methylxanthines

• Drug: Theophylline
• Use: Last-line option only; historical utility
• Caution: Narrow therapeutic window; numerous drug interactions; cardiotoxicity and seizures at toxic levels

6g. Cromolyn / Nedocromil

• Mast cell stabilizers; useful prophylactically in exercise-induced and allergen-triggered asthma
• Limited role in modern management
• Katzung's Basic and Clinical Pharmacology, 16th ed., pp. 555-565; Murray & Nadel's, pp. 1450-1453

---

7. Biologic Therapies (Step 5 - Severe Refractory Asthma)

• Reduce exacerbation frequency (omalizumab reduced hospitalizations by 88%)
• Enable reduction in oral corticosteroid dose
• Improve FEV1 and quality of life
• Best results in patients with repeated exacerbations, high OCS burden, poor lung function
• Katzung, pp. 560-563; Murray & Nadel's, pp. 471-480

---

8. Management of Acute Exacerbations

Definition

Risk Factors for Severe/Fatal Exacerbation (High-Alert Patients)

• History of near-fatal asthma requiring intubation/mechanical ventilation
• Hospitalization or ED visit for asthma in the past year
• Recent oral corticosteroid use (or recent discontinuation)
• Not currently on ICS
• Overuse of SABAs (>1 canister/month)
• Poor adherence; no written asthma action plan
• Comorbid psychiatric disease or food allergy with asthma

Severity Assessment in ED/Acute Setting

• Physical exam: accessory muscle use, ability to complete sentences, respiratory rate, heart rate
• Oxygenation: SpO2; target ≥92%
• PEF or FEV1: classify exacerbation severity
• ABG: mild hypoxemia + respiratory alkalosis; rising PCO2 in absence of improvement = impending respiratory failure
• CXR: if pneumothorax suspected; rarely shows causative findings

Pharmacologic Treatment - Acute

• Mild-Moderate: Albuterol 2-6 puffs via MDI with spacer OR 2.5 mg nebulized, every 20 min until improvement
• Severe: Albuterol 2.5-5 mg q20min + ipratropium bromide 0.5 mg q20min via nebulizer
  • Alternative: Continuous nebulized albuterol 10-15 mg/hour (requires telemetry)
  • Ipratropium added at initiation is associated with physiologic improvements and reduced hospitalization rate; benefit does not persist after admission
• Levalbuterol can substitute but no significant efficacy/side effect advantage over racemic albuterol in adults

• Administer promptly to all patients with exacerbation
• Dose: Prednisone 40-60 mg daily (oral is as effective as IV in equivalent doses)
• Begin taper only after objective improvement (usually 36-48 hours, or PEF >70%)
• Standard course: 7-14 day prednisone taper + initiate ICS at start of taper
• ED discharge: Prednisone 40 mg/day x 5-7 days (with ICS initiation or increase)
• For severe/history of respiratory failure: slower taper

• IV MgSO4 2 g over 20 min: for severe exacerbations refractory to standard therapy after 1 hour
• Acutely improves lung function; most effective in severe, life-threatening exacerbations

• Heliox-driven albuterol nebulization (helium:oxygen 70:30) for severe exacerbations refractory to standard treatment >1 hour
• Reduces turbulent airflow; improves aerosol delivery

• Last-line in acute setting; high toxicity; limited benefit over standard therapy

• Adjunct in status asthmaticus; standard for anaphylactic asthma
• SC/IM 0.5 mg in adults

Indications for Hospital Admission

• Failure to respond to initial treatment (3 SABA treatments q20min x 60-90 min)
• Persistent dyspnea with PEF <70% of baseline after 30-60 min
• Recent hospitalization, failure of aggressive outpatient therapy, prior life-threatening attack
• Rising PCO2 / impending respiratory failure

Hospitalization Threshold is Low for:

• Recent prior hospitalization
• Failed aggressive outpatient management with OCS
• Previous life-threatening attack
• Washington Manual, pp. 335-337; Murray & Nadel's, pp. 610-625; Rosen's Emergency Medicine, pp. 1731-1760

---

9. Brittle Asthma (Special Situation)

• Type I: Sustained chaotic PEF variability daily despite appropriate treatment
• Type II: Well-controlled baseline, but abrupt unpredictable falls in PEF - potentially catastrophic/sudden death
• Management: Maximal ICS therapy often inadequate; consider SC epinephrine autoinjector; allergen avoidance education; medical ID bracelet

---

10. Special Populations

Exercise-Induced Bronchoconstriction (EIB)

• Stimulus: Airway dehydration → increased osmolarity → mediator release (histamine, leukotrienes, prostaglandins)
• Prophylaxis: SABA 5-10 min before exercise (first-line); ICS strongly recommended; LABA + ICS if ICS alone insufficient
• Alternatives: Cromolyn, montelukast, ipratropium before exercise

Cough-Variant Asthma

• Chronic cough as sole presentation; nocturnal predominance; confirm with methacholine challenge
• Treat as standard asthma; rule out ACE inhibitors, GERD, postnasal drip, inducible laryngeal obstruction

Aspirin-Exacerbated Respiratory Disease (AERD)

• Occurs in ~5-10% of asthmatics
• Triad: Asthma + chronic rhinosinusitis with nasal polyposis + NSAID/aspirin sensitivity (COX-1 inhibition)
• Avoid all NSAIDs; leukotriene modifiers are particularly effective

Occupational Asthma

• Remove from sensitizer exposure; standard treatment; monitor PEF at work and away from work

---

11. Non-Pharmacological Management

• Trigger identification and avoidance: allergen removal (house dust mite reduction lowers AHR), occupational agents, smoke
• Influenza vaccination: recommended for all adult asthmatics; Pneumovax for adults 19-64 with chronic illness including asthma (CDC recommendation)
• Weight management: obesity is a comorbidity that worsens control
• Treat comorbidities: sinonasal disease, GERD, OSA, depression

---

12. Patient Education and Monitoring

• Use handheld peak flow meter in relation to personal best PEF
• Green zone (>80% personal best): Well controlled
• Yellow zone (60-80%): Caution - increase reliever, consider OCS
• Red zone (<60%): Medical emergency - immediate bronchodilator + seek care

• Nature of disease; inflammatory vs. bronchospastic components
• Correct inhaler technique (most critical modifiable factor)
• Controller vs. reliever distinction
• Trigger recognition and avoidance
• When to escalate therapy / seek emergency care
• Self-administration of OCS in written action plan
• Fishman's Pulmonary Diseases, pp. 812-813

---

13. Monitoring and Follow-Up

---

14. Summary: Quick-Reference Card

---

---