chronic%20obstructive%20pulmonary%20disease
CHRONIC OBSTRUCTIVE PULMONARY DISEASE

Chronic obstructive pulmonary disease (COPD) is an inflammatory respiratory disease characterized by reversible airflow limitation.

The patient usually has chronic cough, sputum production or dyspnea with or without history of risk factors for the disease.

The chronic airflow limitation is caused by a combination of small airways disease and parenchymal destruction.

It is a preventable and treatable disease.

Supportive Therapy

O2 Therapy - Long-term Management

  • Long-term administration of O2 (>15 hours/day) increases survival in patients with chronic respiratory failure
    • O2 therapy may also benefit hemodynamics, hematologic characteristics, exercise capacity, lung mechanics and mental state
  • Given to patients with stage IV (very severe) COPD with the following:
    • PaO2 ≤55 mmHg (7.3 kPa) or SaO2 ≤88% with or without hypercapnia confirmed 2x over a 3-week period or
    • PaO2 between 55-60 mmHg (7.3-8 kPa) or SaO2 88%, if there is evidence of pulmonary hypertension, peripheral edema suggesting congestive heart failure, or polycythemia (hematocrit >55%)
  • Aim is to increase baseline PaO2 to ≥60 mmHg (8 kPa) and/or produce SaO2 ≥90%, thus preserving vital organ function
  • Reassessment using measurement of ABG or oxygen saturation should be conducted 60-90 days after long-term O2 therapy initiation
  • Inappropriate use of O2 therapy may result in respiratory depression
  • Patients must be given adequate instructions about the source of O2 to be used, method of delivery, duration of use, and flow rates to be used for different levels of physical activity (eg at rest, during exercise, during sleep)
  • Patients should be warned to discontinue smoking when prescribed O2

O2 Therapy - Acute Exacerbation of COPD (Hospital Management)

  • Cornerstone of hospital treatment for COPD exacerbations and in patients with chronic respiratory failure
  • Goal of O2 therapy is to maintain SaO2 88-92% without precipitating respiratory acidosis or worsening hypercapnia
  • SaO2 >93% is not advisable as patient may become drowsy from CO2 retention
  • Once O2 is started, ABG must be checked after 30-60 minutes to ensure adequate oxygenation without CO2 retention or acidosis
    • Blood gases must be monitored regularly depending on response to treatment

Hydration & Nutrition (Acute Exacerbation of COPD)

  • Fluid balance and nutritional status must be monitored and maintained at an optimal level

Non-invasive Mechanical Ventilation (NIV) (Long-term Management)

  • May be considered in patients with stable very severe COPD, especially those with pronounced chronic hypercapnia and history of hospitalization, needing assisted ventilation during exacerbations

Mechanical Ventilation (Acute Exacerbation of COPD)
Non-invasive Mechanical Ventilation (NIV)

  • First-line treatment of acute hypercapnic respiratory failure in COPD exacerbation in patients without contraindications
  • Usually employed in patients with ≥1 of the following: Severe dyspnea with signs of respiratory muscle fatigue, and/or increased work of breathing (eg use of accessory muscles, intercostal space retraction), acidosis (arterial pH ≤7.35 and/or PaCO≥6.0 kPa, 45 mmHg), persistent hypoxemia despite supplemental O2 therapy
  • Has been shown to increase pH, reduce PaCO2, reduce severity of breathlessness in the 1st 4 hours of treatment and decrease length of hospital stay, mortality and intubation rate

Invasive Mechanical Ventilation

  • Utilized in patients with the following:
    • Signs and symptoms: Severe dyspnea, apnea with loss of consciousness, gasping for air, <50 beats/minute PR with loss of consciousness, severe ventricular arrhythmias, psychomotor agitation unresponsive to sedatives, altered mental status in spite of aggressive pharmacotherapy, life-threatening hypoxemia unresponsive to NIV
    • Severe hemodynamic compromise unresponsive to hydration and medications
    • Massive aspiration
    • Unable to suction respiratory secretions
    • With contraindications to or failed NIV
    • Impending or previous respiratory or cardiac failure
  • There is a major risk of ventilator-associated pneumonia, barotrauma and failure to wean
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