2.2 Pulmonology & Respiratory Care

Pulmonology & Respiratory Care

Asthma (GINA Guidelines)

The Global Initiative for Asthma (GINA) guidelines represent a paradigm shift in asthma management by moving away from short-acting beta-agonists (SABA) alone for rescue therapy. Relying solely on SABAs increases the risk of severe exacerbations, downregulates beta-receptors, and is associated with asthma-related mortality. Instead, GINA recommends Inhaled Corticosteroid (ICS) therapy for all patients with asthma to address underlying inflammation.

The preferred reliever therapy across all steps of asthma severity in adults and adolescents is a combination of a low-dose ICS and formoterol (a fast-onset, long-acting beta-agonist, LABA). This approach, known as Single Maintenance And Reliever Therapy (SMART), ensures that the patient receives anti-inflammatory treatment every time they require symptom relief.

• Step 1 and 2: As-needed low-dose ICS-formoterol.
• Step 3: Low-dose ICS-formoterol as maintenance AND as-needed reliever.
• Step 4: Medium-dose ICS-formoterol as maintenance AND as-needed reliever.
• Step 5: High-dose ICS-formoterol, plus consideration for add-on therapies such as LAMA (tiotropium) or biologic agents.

Acute Asthma Exacerbations: Management in the ED involves repeated doses of SABA (albuterol) and ipratropium bromide (only in the ED setting, not for chronic use). Systemic corticosteroids (e.g., prednisone 40-50 mg daily for 5-7 days) should be initiated within 1 hour of presentation for moderate to severe exacerbations. IV magnesium sulfate (2 grams over 20 minutes) is considered for severe, life-threatening exacerbations unresponsive to initial treatments to induce smooth muscle relaxation.

Targeted Biologic Therapies for Severe Asthma: Biologics target specific inflammatory pathways and are reserved for severe, uncontrolled asthma at Step 5.

• Omalizumab: A monoclonal antibody that binds to IgE. Indicated for moderate-to-severe allergic asthma. Dosing is based on baseline serum IgE levels and body weight. Carries a black box warning for anaphylaxis.
• Mepolizumab, Reslizumab, and Benralizumab: Interleukin-5 (IL-5) antagonists that deplete eosinophils. Indicated for severe eosinophilic asthma. Eosinophil counts (typically >150-300 cells/µL depending on the drug) must be documented prior to initiation.
• Dupilumab: An IL-4 receptor alpha antagonist that inhibits both IL-4 and IL-13 signaling. It is highly effective for patients with severe eosinophilic asthma or those dependent on oral corticosteroids.

Specific Phenotypes: Aspirin-Exacerbated Respiratory Disease (AERD) is characterized by the triad of asthma, chronic rhinosinusitis with nasal polyps, and sensitivity to aspirin/NSAIDs. Leukotriene receptor antagonists (LTRAs) like montelukast, or biologics like dupilumab, are highly beneficial.

Chronic Obstructive Pulmonary Disease (COPD - GOLD Criteria)

COPD is characterized by persistent, largely irreversible airflow limitation. The GOLD guidelines classify severity using a combined assessment of spirometry (GOLD 1 to 4) and symptom burden/exacerbation history. Symptom assessment utilizes the Modified Medical Research Council (mMRC) dyspnea scale or the COPD Assessment Test (CAT). The updated ABCD assessment tool merged groups C and D into a single Group E, emphasizing the clinical importance of exacerbation history.

• Group A (mMRC 0-1, CAT < 10; 0-1 moderate exacerbations): Any bronchodilator (SABA, SAMA, LABA, or LAMA).
• Group B (mMRC ≥ 2, CAT ≥ 10; 0-1 moderate exacerbations): LABA plus LAMA combination is strictly preferred over monotherapy to improve symptom burden and lung function.
• Group E (Any symptoms; ≥2 moderate exacerbations or ≥1 exacerbation leading to hospitalization): LABA plus LAMA. If blood eosinophils are ≥ 300 cells/µL, a triple therapy consisting of ICS + LABA + LAMA is highly recommended to reduce exacerbation frequency.

ICS Use in COPD: Unlike asthma, ICS monotherapy is strictly contraindicated in COPD due to a lack of efficacy in preventing lung function decline and a significantly increased risk of pneumonia. ICS should only be used in combination (triple therapy) in patients with a history of recurrent exacerbations and elevated blood eosinophils (≥ 300 cells/µL, or > 100 cells/µL with ≥ 2 exacerbations).

Chronic Exacerbation Prevention: For patients with severe COPD and chronic bronchitis phenotype who continue to have exacerbations despite optimal inhaler therapy, add-on options include:

• Roflumilast: A PDE-4 inhibitor that reduces lung inflammation. It is contraindicated in moderate-to-severe liver impairment. Key adverse effects include severe diarrhea, significant weight loss (requiring routine weight monitoring), and psychiatric adverse events (anxiety/depression).
• Azithromycin: Chronic daily or three-times-weekly macrolide therapy reduces exacerbations through its anti-inflammatory and immunomodulatory properties. Monitor for QTc prolongation and hearing loss.

Acute Exacerbation of COPD (AECOPD): Treated with short-acting bronchodilators, systemic corticosteroids (prednisone 40 mg daily for 5 days), and antibiotics if the patient exhibits all three cardinal symptoms (increased dyspnea, increased sputum volume, and increased sputum purulence), or two symptoms if one is purulence, or if requiring mechanical ventilation. Standard empiric antibiotics (macrolides, doxycycline, or amoxicillin/clavulanate) target H. influenzae, S. pneumoniae, and M. catarrhalis. Non-invasive positive pressure ventilation (NIPPV) is the preferred ventilatory support for acute respiratory failure associated with AECOPD.

Inhaled Delivery Devices and Technique: Selecting the correct device is as critical as selecting the correct medication, as up to 70% of patients use their inhalers incorrectly.

Adverse Effects of Inhaled Therapies:

• ICS: Oropharyngeal candidiasis (thrush), dysphonia, and cough. Patients must be counseled to rinse their mouth and spit after use. Systemic effects (bone loss, cataracts) are rare at low-to-medium doses.
• LABA/SABA: Tachycardia, tremor, and hypokalemia (due to intracellular potassium shift).
• LAMA/SAMA: Anticholinergic effects such as dry mouth (most common), urinary retention, and increased intraocular pressure. Caution in BPH or narrow-angle glaucoma.