C.O.P.D

Chronic Obstructive Pulmonary Disease (C.O.P.D) encompasses chronic bronchitis (“blue bloaters“) and emphysema (“pink puffers“)

Pathophysiology: Inflammation leading to mucus hypersecretion and destruction of alveolar walls. The airway walls become weak and close (or “obstruct”) as patient tries to exhale, trapping air (including CO₂) in the lungs

Risk factors:

1. Smoking
2. Alpha-1-antitrypsin deficiency (genetic)
3. Intravenous Drug Use
4. HIV

Diagnosis:

• Outpatient
  • Pulmonary Function Tests
    • Obstruction diagnosed by: FEV₁/FVC < 0.7
    • No bronchodilator response (<12% increase or <200 mL increase in Tidal Volume)
    • No methacholine response
    • Emphysema: Decrease in DLCO
    • Chronic Bronchitis: Normal DLCO
• Inpatient “Exacerbation” (if patient has known COPD)
  • New cough
  • Change in sputum production (increased amount or change in color)
  • Increase in dyspnea
  • ABG may show increased P_aCO₂ (due to retention) and a low pH, because of the following formula: CO₂ + H₂O <–> H₂CO₃ <–> H⁺ + HCO₃^–

Outpatient Management

• Non-Pharmacologic
  • Smoking cessation
  • Exercise regimen
  • Supplemental Oxygen (target an SpO2 ~88-92)
  • Immunization (Influenza and Pneumococcal)
  • BiPAP (if CO₂ retention)
  • Procedures
    • Lung reduction surgery (especially if emphysematous changes are worse in the upper lobes of the lung)
    • Placement of one-way endobronchial valves to prevent CO₂ retention
    • Lung transplant

• Pharmacologic
  1. SABA or SAMA (Short-Acting Beta-Agonist or Short-Acting Muscarinic Antagonist)
     • Can combine if necessary
     • Can use nebulizers if patients have difficulty with inhalation
     • Ex. albuterol (SABA), ipraptropium (SAMA)
  2. LABA or LAMA (Long-Acting Beta-Agonist or Long-Acting Muscarinic Antagonist)
     • Whichever is started first, other can be added as next step
     • Ex. formoterol, salmeterol (LABAs), tiotropium, aclidinium (LAMAs)
  3. ICS (Inhaled corticosteroids)
     • Ex. Fluticasone, mometasone, budesonide
     • Especially beneficial in patients with peripheral eosinophilia
  4. Antibiotics
     • Macrolides have been shown to decrease frequency of exacerbations (usually Monday, Wednesday, Friday dosing)
  5. Roflumilast
     • Phosphodiesterase-4 Inihibitor
     • Can help prevent re-hospitalization
     • Notable side effect: Diarrhea
  6. Biologic Agents (if asthma-COPD overlap syndrome)
     • Ex. Omalizumab (anti-IgE) vs mepolizumab (anti-IL-5)

Inpatient “Exacerbation” Management

• Investigate underlying cause of exacerbation
  • Chest X-Ray: to rule out alternative diagnosis
  • Respiratory viral panel
  • CBC: Assess for polycythemia, anemia, or leukocytosis
  • EKG: to look for underlying ischemia
  • Consider CTA if concern for PE

• Acute Respiratory Failure
  • Supplemental oxygen
    • Nasal cannula vs heated high-flow
    • BiPAP
    • Intubation if necessary

• Obstruction
  • Continue home long-acting inhalers
  • Start combined albuterol/ipratropium nebulizer scheduled (NOT PRN) q4hours-q6hours

• Inflammation
  • Steroids
    • Typically start with IV methylprednisolone on day 1 (40-120 mg x1 dose)
    • Change to PO prednisone 40 mg qday on the second day (course of 5-10 days)
  • Antibiotics
    • Azithromycin, doxycyline, levofloxacin for anti-inflammatory effects as well as to cover atypical pathogens for a course of 5-7 days