- Clinical science
Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is defined as the acute worsening of respiratory symptoms in a patient with COPD that necessitates additional therapy. The most common trigger of AECOPD is respiratory viral infection. Cardinal symptoms of AECOPD include worsening of dyspnea, increased frequency and severity of cough, and increased volume and/or purulence of sputum. AECOPD is a clinical diagnosis and the diagnostic workup serves primarily to assess the level of severity and evaluate for any underlying trigger and coexisting comorbidities. Management of AECOPD consists primarily of respiratory support, inhaled bronchodilator therapy, and systemic corticosteroids. Antibiotics should be considered in patients with severe AECOPD and patients who are mechanically ventilated. See also “COPD” and “Mechanical ventilation.”
- Viruses: Most cases of AECOPD are caused by respiratory viral infections. 
- Bacterial infections, e.g., Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pneumoniae
- Additional triggers: drugs (e.g., beta blockers), allergens, air pollution, stress
- Risk factors: previous exacerbation, advanced COPD stage 
- Cardinal symptoms of AECOPD 
- Possible additional symptoms
- Signs of severe AECOPD
- AECOPD is a clinical diagnosis (see “Cardinal symptoms of AECOPD”).
- The goals of diagnostic evaluation are to:
- Consider empiric bronchodilator therapy if the diagnosis is unclear.
Testing should not delay urgent treatment in patients presenting with signs of respiratory failure or distress if clinical criteria of AECOPD are met.
- Arterial blood gas: to assess the level of severity
- Microbiological studies
- Additional workup for alternate diagnoses and relevant comorbidities: as guided by clinical suspicion
PaCO2 on blood gas should be interpreted in relation to the patient's baseline because of chronic CO2 retention.
- Chest x-ray
- CTA chest: to rule out pulmonary embolism as directed by pretest probability (see “Wells criteria for PE”)
Spirometry is not routinely recommended in the assessment of AECOPD. 
- Potential uses include:
- Confirming the diagnosis for first-time patients (see “Diagnosis of COPD”)
- Grading the severity of disease for prognostication 
- Interpretation of changes in FEV1: 
- Can predict poor outcomes and treatment failure
- Correlates poorly with the risk of subsequent exacerbations
The following system is recommended to classify AECOPD severe enough to require a hospital visit and is based on clinical and laboratory parameters. For baseline classification, see “COPD classification.” 
|Classification of AECOPD |
|Clinical or laboratory parameter||AECOPD with life-threatening acute respiratory failure||AECOPD with non-life-threatening acute respiratory failure||AECOPD without respiratory failure|
|Respiratory rate|| || |
Accessory muscle use
| || |
Change in baseline mental status
| || |
Degree of hypoxemia
| || |
The overarching goal of treatment in AECOPD is to minimize the impact of the current exacerbation and prevent subsequent exacerbations. 
Approach to the management of AECOPD 
- AECOPD with life-threatening acute respiratory failure
- AECOPD with non-life-threatening acute respiratory failure
AECOPD without respiratory failure
- Oxygen supplementation
- Standard pharmacological treatment (see “ ”)
- Decide outpatient vs. inpatient treatment 
Acute exacerbation of COPD may be a life-threatening emergency. Rapid assessment is recommended to identify patients who require aggressive care and admission to ICU.
- Supplemental oxygen (see “Oxygen therapy”)
- HFNC oxygen therapy: rates up to 60 L/min 
NIPPV is the recommended first-line ventilatory strategy in AECOPD with acute respiratory failure. NIPPV is associated with a decreased need for intubation, decreased hospital length-of-stay, and lower mortality. 
- Indications for NIPPV in patients with AECOPD (only one of the following is required): 
Intubation and mechanical ventilation are especially high-risk and complication-prone procedures in AECOPD, and they are generally used as a last resort (see “High-risk indications for mechanical ventilation”). 
Indications for intubation in patients with AECOPD 
- Respiratory failure
- Altered mental status
- Persistent vomiting
- Large aspiration
- Pulmonary hygiene: persistent inability to clear respiratory secretions
- Hemodynamic instability
- Procedure: See “High-risk indications for mechanical ventilation” and “Ventilation strategy for obstructive lung disease.”
- Postintubation management
Intubation and mechanical ventilation of patients with AECOPD carries a significant risk of periprocedural cardiac arrest due to rapid oxygen desaturation, dynamic hyperinflation, circulatory shock, and/or severe respiratory acidosis! Countermeasures should be taken prior to performing these procedures (see “High-risk indications for mechanical ventilation”).
Pharmacological therapy for AECOPD 
The following are suggested pharmacological treatment combinations based on symptom severity.
- AECOPD without respiratory failure: standard pharmacological treatment
- AECOPD with respiratory failure (non-life-threatening or life-threatening): aggressive pharmacological treatment
Inhaled SABAs (e.g., albuterol, levalbuterol): mainstay of treatment due to their rapid bronchodilator effect
- High-dose inhaled SABA
- Standard dose inhaled SABA: albuterol MDI
- Route of application: There is no difference in effectiveness between MDIs and nebulizers. 
- Consider a nebulizer in patients who are sicker, i.e., unable to effectively use an inhaler.
- MDI is associated with decreased adverse effects and less aerosolization of airborne infectious pathogens. 
- Inhaled LABA (with or without combination inhaled corticosteroid) should be either continued if it has been part of the patient's chronic therapy or started just prior to discharge. 
- Inhaled SABAs (e.g., albuterol, levalbuterol): mainstay of treatment due to their rapid bronchodilator effect
- Anticholinergics: inhaled SAMA (e.g., ipratropium bromide; nebulizer , ipratropium bromide inhaler )
- Combined therapy: ipratropium bromide/albuterol sulfate nebulizer
- Indications: Consider in all patients with AECOPD. 
- Commonly used regimens: 
- Oral agents are equally as effective as IV agents. 
- A 5-day course is usually sufficient for most patients but some patients may benefit from a longer course and/or a steroid taper. 
- Inhaled corticosteroids
The routine use of antibiotics in AECOPD is controversial, but antibiotics are associated with enhanced symptom resolution and a lower risk of treatment failure in patients with moderate to severe AECOPD. 
- Indications for empiric antibiotic therapy in AECOPD (presence of any of the following) 
- Recommended regimen
- Duration of treatment
Adjunctive treatment and supportive care 
- Smoking cessation and counseling
- Supplement vitamin D for confirmed deficiency. 
- Diuretics for fluid overload
- VTE prophylaxis
- Nutritional support
- Treatment of associated comorbidities (e.g., ACS, heart failure, pulmonary embolism)
- Isolation precautions to prevent transmission of suspected respiratory pathogens
- Symptom surveillance and severity assessment, as clinically indicated
- Continuous pulse oximetry
- Serial blood gas monitoring
Indications for hospital admission 
- Acute respiratory failure
- Severe symptoms
- New physical examination signs
- Condition refractory to initial medical treatment
- Significant comorbidity
- Insufficient home/community support system
Indications for ICU admission 
- Life-threatening acute respiratory failure
- Severe dyspnea refractory to aggressive medical treatment
- Hemodynamic instability requiring vasopressors
Clinical decision tools 
The following assessment measures may help to objectively identify patients at risk of poor medical outcomes.
- 3-minute walk test 
|Ottawa COPD Risk Scale (OCRS) |
Evaluation on arrival
Prior intervention for PVD
Prior intubation for respiratory distress
Pulse ≥ 110/min
|Diagnostic test results|| |
Hemoglobin < 10 g/dL
BUN ≥ 34 mg/dL
Serum CO2 ≥ 35 mEq/L
Pulmonary congestion on CXR
|Evaluation after initial treatment|| |
Interpretation: A higher total score corresponds to an increased risk of serious short-term outcomes.
- Supplemental oxygen to maintain target SpO2 88–92%
- Continuous pulse oximetry
- Serial blood gas monitoring
- Trial NIPPV before intubation (if applicable).
- Evaluate for indications for intubation in patients with AECOPD.
- Consider admission to ICU for deteriorating patients.
- Start pharmacological therapy for AECOPD.
- Consider indications for empiric antibiotic therapy in AECOPD.
- Identify and treat the underlying cause.
- Provide supportive care.