On this page
Quick Reference
Overview and Recommendations
Background
- •Define an acute exacerbation (AECOPD) as a clinical event characterized by increased , cough, or sputum production beyond daily variations that requires a change in therapy.
- •Recognize the primary triggers, which include respiratory viruses (Rhinovirus is most common, followed by Influenza and RSV), bacterial pathogens (Nontypeable Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis), and environmental pollutants.
- •Understand the clinical impact of exacerbations, which drive the "multidimensional progression" of , often leading to a permanent loss of lung function and increased risk of future cardiovascular events for up to 6 months post-discharge.
- •Classify exacerbations by severity based on the required intervention: Mild (treated with short-acting bronchodilators only), Moderate (requires oral corticosteroids and/or antibiotics), and Severe (requires hospitalization or emergency department evaluation).
- •Identify high-risk phenotypes, such as patients with frequent exacerbations (≥2 per year), those with underlying frailty, or those with comorbid , all of whom face significantly higher mortality and readmission rates.
Evaluation
- •Suspect AECOPD in any patient with known COPD presenting with the Anthonisen triad: increased dyspnea, increased sputum volume, and increased sputum purulence.
- •Ask about the prodromal phase, specifically looking for subtle increases in cough or changes in sputum color that preceded the acute escalation of symptoms.
- •Examine the patient for signs of respiratory distress, including accessory muscle use, paradoxical chest wall movement, and the presence of new wheezing or crackles on auscultation.
- •Obtain immediate and target an initial saturation of 88–92% while awaiting further diagnostic testing.
- •Order an Arterial Blood Gas (ABG) for any patient with SpO2 <92%, significant respiratory distress, or altered mental status to identify acute (pH <7.35 and PaCO2 >45 mmHg).
- •Perform Point-of-Care Ultrasound (POCUS) using the EMERALD-US protocol to rapidly differentiate AECOPD from (look for B-lines) and pneumonia (look for consolidation).
- •Rule out pulmonary embolism (PE) in patients with unexplained exacerbations, pleuritic chest pain, or dyspnea out of proportion to clinical signs, using D-dimer or CT (CTPA).
- •Order a Chest X-ray (CXR) to screen for concomitant pneumonia, which occurs in approximately 48.7% of hospitalized AECOPD cases, or to rule out a .
- •Check admission blood eosinophil counts; levels <100 cells/µL are associated with higher inpatient mortality and may suggest a lower likelihood of response to corticosteroids.
- •Utilize serum procalcitonin (PCT) to guide antibiotic therapy; consider withholding antibiotics if PCT <0.1 ng/mL and strongly encourage them if PCT >0.25 ng/mL.
- •Obtain an ECG and NT-proBNP to screen for acute cardiovascular events (CVEs), such as new-onset or left ventricular dysfunction, which are common during the acute phase.
- •Apply the 5-item CERT checklist to confirm the diagnosis; a score of ≥2 moderate-to-severe items is considered positive for an exacerbation.
Management
- •Administer short-acting β2-agonists (SABA) such as Salbutamol 2.5–5 mg via nebulization every 1–4 hours as needed for rapid bronchodilation.
- •Combine SABA with a short-acting muscarinic antagonist (SAMA) like Ipratropium bromide 0.5 mg every 4–6 hours, as the combination is superior to monotherapy in reducing hospitalizations.
- •Prescribe systemic corticosteroids to improve FEV1 and shorten hospital stay; the standard regimen is Prednisone 40 mg orally once daily for exactly 5 days.
- •Consider nebulized Budesonide 2 mg every 6 hours as an alternative to systemic steroids if the patient has contraindications to oral/IV glucocorticoids or to reduce systemic side effects.
- •Initiate empiric antibiotics for patients with increased sputum purulence or those requiring mechanical ventilation; first-line options include Amoxicillin/Clavulanate 875/125 mg BID or Azithromycin 500 mg on day 1 followed by 250 mg daily for 5 days.
- •Maintain controlled oxygen therapy to a target SpO2 of 88–92%; avoid high-concentration oxygen which can worsen hypercapnia via the Haldane effect and ventilation-perfusion mismatch.
- •Initiate Non-Invasive Ventilation (NIV) for patients with respiratory acidosis (pH <7.35) or persistent dyspnea despite medical therapy; start with BiPAP at IPAP 10–12 cm H2O and EPAP 4–5 cm H2O.
- •Monitor ABG within 1–2 hours of starting NIV; if pH remains <7.30 and the patient is not improving, escalate to intensive care for possible .
- •Utilize High-Flow Nasal Oxygen (HFNO) as a comfortable alternative to NIV in patients with mild-to-moderate hypercapnic respiratory failure (pH 7.25–7.35).
- •Avoid the use of morphine for anxiety in patients with concomitant COPD and heart failure; midazolam is preferred if sedation is absolutely necessary for NIV tolerance.
- •Transition the patient to long-acting bronchodilators, such as Tiotropium 18 µg daily or Salmeterol 50 µg BID, before hospital discharge to prevent early recurrence.
- •Implement early mobilization and rehabilitation, such as using a pedal exerciser during the hospital stay, to improve muscle strength and balance.
- •Provide nutritional support for malnourished patients, specifically high-protein supplements containing beta-hydroxy-beta-methylbutyrate (HP-HMB) twice daily.
- •Refer patients with significant functional impairment or slow gait speed to rapid access rehabilitation (RAR) programs upon discharge.
- •Ensure a follow-up appointment within 1–2 weeks of discharge to assess the Assessment Test (CAT) score and adjust maintenance therapy.
Board Review — High Yield
- •Anthonisen Criteria — Diagnosis requires increased dyspnea, sputum volume, and sputum purulence.
- •Target SpO2 — 88–92% is the goal to prevent worsening hypercapnia and acidosis.
- •REDUCE Trial — Established that 5 days of systemic corticosteroids is non-inferior to 14 days for AECOPD.
- •Eosinophils — Low admission counts (<100 cells/µL) are a marker of poor prognosis and reduced steroid response.
- •NIV Indications — pH <7.35 and PaCO2 >45 mmHg; it reduces the need for intubation and decreases mortality.
- •Rhinovirus — The most frequently identified viral trigger for acute exacerbations.
- •Procalcitonin — A validated tool to reduce unnecessary antibiotic use; withhold if <0.1 ng/mL.
- •Pulmonary Embolism — Found in up to 25% of patients hospitalized with unexplained COPD exacerbations.
Deep Dive — Evidence Details
Definition, Synonyms, and Classification
- ▸AECOPD is defined by a sustained worsening of respiratory symptoms beyond daily variation that necessitates a change in medication [5].
- ▸The severity of an exacerbation is classified by the level of healthcare utilization (Mild: SABA only; Moderate: Antibiotics/Steroids; Severe: Hospitalization) [5].
- ▸Exacerbations are key drivers of COPD progression and have a multidimensional impact on patient prognosis and quality of life [3].
An acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a clinical event characterized by a sustained worsening of the patient's respiratory symptoms—specifically , cough, and/or production—that is beyond normal day-to-day variations and necessitates a change in regular medication [5]D. These episodes are no longer viewed as mere epiphenomena but as critical events in the natural history of that drive disease progression, impair quality of life, and significantly worsen the long-term prognosis [3]D.
Synonyms and Alternate Names
While " " (AECOPD) is the standard clinical term, several other descriptors are used in literature and practice:
- COPD Flare-up: A common patient-facing term used to describe the acute worsening of symptoms.
- Clinical Decompensation of COPD: Often used to describe the physiological breakdown of compensatory mechanisms during an event [3]D.
- Acute-on-Chronic Respiratory Failure: Specifically refers to severe exacerbations where gas exchange is significantly compromised.
- Unscheduled Medical Consultation: A definition often used in clinical trials to capture events requiring urgent care [1].
Clinical Phases of an Exacerbation
Understanding the temporal trajectory of an exacerbation is essential for timing interventions. The clinical course is generally divided into five distinct phases:
- Prodromal Phase: The period immediately preceding the acute event, often characterized by subtle increases in cough or a change in the color of .
- Progressive (Acute) Phase: The period of active worsening where symptoms escalate beyond the patient's baseline, often triggered by viral or bacterial pathogens [2]D[6]D.
- Nadir: The point of maximal physiological impairment and symptom severity. This is the stage where the risk of is highest.
- Plateau Phase: A period where symptoms have stabilized following medical intervention (e.g., prednisone 40 mg daily) but have not yet begun to improve.
- Recovery Phase: The gradual return to the patient's pre-exacerbation baseline. It is important to note that not all patients return to their previous level of lung function, contributing to the "multidimensional progression" of the disease [3]D.
The Evolution of Definitions
The definition of AECOPD has shifted from purely symptom-based criteria to healthcare-utilization-based criteria. The Anthonisen criteria, established in 1987, focus on three cardinal symptoms: increased , increased sputum volume, and increased sputum purulence [1]. In contrast, the GOLD (Global Initiative for Chronic Obstructive Lung Disease) definition is more pragmatic, defining an exacerbation by the intensity of the medical intervention required [5]D.
Clinicians must recognize that healthcare-utilization definitions may be confounded by a patient's access to care rather than the underlying pathophysiology [5]D. For instance, a patient with severe biological inflammation who cannot access a clinic may be misclassified as having a "mild" exacerbation simply because they did not receive a prescription for or [1].
Classification by Severity
The current standard for classifying the severity of an exacerbation is based on the level of intervention required to stabilize the patient [5]D.
| Severity Grade | Clinical Definition | Requirement |
|---|---|---|
| Mild | Symptoms manageable with increased dosage of regular medications | Treated with short-acting bronchodilators (SABA) only |
| Moderate | Symptoms requiring escalation of therapy beyond bronchodilators | Treated with SABA plus and/or oral |
| Severe | Symptoms requiring urgent or emergent medical evaluation | Requires hospitalization or emergency room visit; may involve acute |
Etiological Variants and Pathotypes
Exacerbations are not homogeneous; they are driven by diverse triggers that influence the microbial community structure within the lungs [6]D.
| Variant Name | Key Distinguishing Feature | Associated Pathogens/Factors |
|---|---|---|
| Viral Exacerbation | Often preceded by upper respiratory symptoms; high seasonal prevalence | Human Rhinovirus (HRV-A, B, or C) is most common [2]D |
| Bacterial Exacerbation | Characterized by increased sputum purulence and volume | H. influenzae, S. pneumoniae, or opportunistic pathogens like Ralstonia mannitolilytica [4]D[6]D |
| Fungal/Mixed | Often seen in severe, hospitalized cases; involves complex microbial dynamics | Aspergillus species or diverse fungal communities identified via ITS DNA sequencing [6]D |
| Environmental | Triggered by non-infectious insults | Pollution, particulate matter, or cold weather |
| Type | Criteria | Clinical Significance |
|---|---|---|
| Type I (Severe) | Presence of all 3: Increased dyspnea, sputum volume, and sputum purulence | Highest likelihood of bacterial infection; strongest indication for antibiotics [1] |
| Type II (Moderate) | Presence of any 2 of the cardinal symptoms | Intermediate risk; antibiotics indicated if purulence is one of the symptoms |
| Type III (Mild) | Presence of 1 cardinal symptom plus at least one: URTI in last 5 days, fever, increased wheeze, or increased heart/respiratory rate | Lowest likelihood of bacterial etiology |
Etiology and Triggering Factors
- ▸Respiratory infections (viral and bacterial) are the primary triggers for AECOPD.
- ▸Rhinovirus is the most common viral trigger, while H. influenzae is the most common bacterial isolate.
- ▸Viral infections are detected in approximately 41.2% of severe exacerbations.
- ▸Bacterial involvement is predicted by sputum purulence and fever in about 50% of cases.
- ▸Influenza vaccination significantly reduces the incidence of AECOPD.
- ▸HFNO is clinically noninferior to NIV in managing COPD exacerbations with respiratory acidosis.
- ▸RSV-ARI in older adults increases the long-term risk of subsequent COPD exacerbations.
Overview of Triggers
Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are primarily triggered by respiratory infections, which account for a significant proportion of hospitalizations [13]. These events are characterized by an acute worsening of respiratory symptoms, often necessitating escalated support such as high-flow nasal oxygen (HFNO) or noninvasive ventilation (NIV) [8][9]. While infections are the predominant cause, environmental factors and comorbidities also play critical roles in triggering these episodes [11][114].
Viral Pathogens
Respiratory viruses are a major driver of AECOPD, particularly in community-managed cases where they are causally associated with symptom onset [22].
- Incidence and Detection: Viral infections are detected in approximately 41.2% of severe AECOPD cases requiring emergency department visits or hospitalization [29]D. Multiplex PCR panels have improved detection rates, identifying viruses in nearly half of some cohorts [12][29]D.
- Common Viral Agents: The most frequently isolated virus is Rhinovirus, followed by Respiratory Syncytial Virus (RSV) and Influenza [29]D. RSV-related acute respiratory illnesses (RSV-ARI) in patients aged ≥50 years are associated with significant long-term risks, including subsequent COPD exacerbations and heart failure hospitalizations [114].
- Influenza: Influenza infection is a critical trigger; predictors of influenza PCR positivity in AECOPD patients include higher body temperature and lower lymphocyte counts [26]D. Influenza vaccination has been shown to significantly reduce the frequency of acute respiratory illnesses and AECOPD episodes over a 1-year period [15].
- COVID-19: The SARS-CoV-2 pandemic introduced a new cohort of acute respiratory failure (ARF). While COVID-19 itself triggers exacerbation-like states, the associated infection control measures (masking, social distancing) led to a worldwide reduction in other respiratory infections, which in turn decreased the incidence of exacerbations in other chronic lung diseases like idiopathic pulmonary fibrosis [119].
Bacterial Pathogens
Bacterial involvement is established in approximately 50% of severe AECOPD cases [117].
- Common Pathogens: The most prevalent bacterial isolates include Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, and Staphylococcus aureus [10][116]. In smokers, H. influenzae remains the most common pathogen [10].
- Diagnostic Indicators: Bacterial involvement is often predicted by the presence of purulent sputum and hyperthermia [117]. The Streptococcus pneumoniae urinary antigen test is positive in approximately 17.1% of AECOPD hospitalizations, rising to 20.6% when concomitant pneumonia is present [14].
- Concomitant Pneumonia: Pneumonia is often considered a distinct entity from simple AECOPD. Patients with pneumonia and COPD (PCOPD) typically present with higher levels of C-reactive protein (CRP) and longer hospital stays compared to those with ECOPD alone [120].
Comorbidities and Systemic Factors
Exacerbations are frequently complicated or triggered by extrapulmonary conditions:
- Cardiovascular Links: Acute respiratory failure in COPD often overlaps with acute cardiogenic pulmonary edema (ACPE) [9][11]. Chronic bronchitis and acute respiratory infections are also identified as independent risk factors for ischemic stroke [121].
- Immunocompromised States: Patients with HIV-1 infection who develop acute respiratory distress syndrome (ARDS) or severe respiratory failure face higher mortality rates than non-infected counterparts, with a median CD4 count of 75 in severe cases [115].
- Smoking: Active smoking increases the risk of respiratory tract infections by altering the epithelial cell surface, facilitating bacterial colonization by pathogens like H. influenzae [10].
Economic and Clinical Impact
AECOPD represents a massive economic burden on healthcare systems. In regions like Madrid, respiratory diseases causing acute respiratory failure are among the primary reasons for prehospital emergency medical service (EMS) utilization [11]. Clinical trials such as RENOVATE have demonstrated that for COPD patients with respiratory acidosis, HFNO is noninferior to NIV regarding the risk of intubation or death within 7 days, though cost-minimization analyses suggest varying economic impacts depending on the specific ARF subgroup [8][9].
| Pathogen Type | Specific Agents | Prevalence/Notes |
|---|---|---|
| Viral | Rhinovirus, RSV, Influenza, Coronavirus | Detected in ~41% of severe cases [29]D |
| Bacterial | H. influenzae, S. pneumoniae, M. catarrhalis | Found in ~50% of severe cases [117] |
| Atypical | Mycoplasma pneumoniae, Chlamydia pneumoniae | Less common; often identified via serology [12] |
Diagnosis and Workup
- ▸High-flow nasal oxygen (HFNO) is noninferior to NIV for COPD exacerbations with respiratory acidosis regarding 7-day intubation/death rates.
- ▸Point-of-care ultrasound (POCUS) provides 100% sensitivity for pleural effusion and interstitial lung disease in acute dyspnea.
- ▸Frailty is a potent independent predictor of in-hospital mortality in AECOPD (HR 2.25).
- ▸Vibrating mesh nebulizers (VMN) achieve better drug deposition than jet nebulizers during non-invasive ventilation.
- ▸Gait speed <0.8 m/s at discharge predicts poor outcomes in hypercapnic respiratory failure survivors.
- ▸Dexamethasone 8 mg/d prevents acute mountain sickness in COPD patients traveling to high altitudes.
Clinical Presentation and Early Detection
Acute exacerbations of COPD (AECOPD) are characterized by increased airway obstruction, mucus production, and air trapping, which manifest as changes in lung acoustics [56]D. Computerized adventitious respiratory sounds (ARS) have been shown to change significantly during the acute phase compared to stable states, potentially serving as a tool for monitoring recovery [56]D. Early recognition is critical; the 14-item EXACT diary and the 5-item CERT checklist are both validated tools for identifying exacerbations, with the CERT checklist providing a more patient-centered, binary approach (positive if ≥2 items are rated moderate/severe) [43]D.
Laboratory Investigations and Biomarkers
Standard workup includes inflammatory and hemostatic markers. Patients with AECOPD exhibit significant alterations in clot microstructure, specifically a higher fractal dimension (df), indicating increased thrombogenicity compared to stable COPD [44]D.
- Eosinophil Counts: Admission blood eosinophil counts are prognostic; however, in a large retrospective study, they were not independently associated with inpatient mortality or 1-year death after adjusting for acute illness markers [47]D.
- Procalcitonin (PCT): In the ICU setting, using a PCT-guided algorithm to initiate or stop antibiotics was found to be noninferior to standard therapy regarding 3-month mortality, though it did not significantly reduce antibiotic exposure in severe cases [35].
- Viral Screening: Respiratory viruses are detected in approximately 41.2% of severe AECOPD cases, with rhinovirus and influenza being common [29]D. Predictors of influenza PCR positivity include higher body temperature, lower malignancy rates, and higher white cell counts [26]D.
Imaging and Point-of-Care Ultrasound (POCUS)
While chest X-ray remains a standard first-line investigation, Point-of-Care Ultrasound (POCUS) offers high diagnostic accuracy. POCUS has demonstrated 100% sensitivity and specificity for diagnosing pleural effusion and interstitial lung disease, and 92.3% sensitivity for pneumonia in dyspneic patients [45]D. Artificial Intelligence (AI) models are increasingly used to support diagnosis in hospitalized patients, though clinicians must be wary of systematic biases; image-based AI explanations may help mitigate but not entirely eliminate diagnostic errors [32].
Physiological Assessment and Risk Stratification
Functional and physiological markers are essential for prognosis. Frailty is a significant independent predictor of in-hospital mortality (Hazard Ratio 2.25 in validation cohorts) [39].
- Gait Speed: A gait speed of <0.8 m/s at hospital discharge is associated with a higher risk of death or readmission in survivors of acute hypercapnic respiratory failure [50]D.
- Sarcopenia: Acute sarcopenia, defined by dynamic changes in muscle quantity (e.g., bilateral anterior thigh thickness) and handgrip strength, can be triggered by the stress of an exacerbation [46]D.
- Cardiac Risk: The Get With the Guidelines-Heart Failure (GWTG-HF) risk score, while designed for heart failure, correlates with B-type natriuretic peptide levels and may assist in identifying comorbid cardiac risk during AECOPD [53]D.
Respiratory Support and Monitoring
For patients with respiratory acidosis (pH <7.30 and PaCO2 >6.0 kPa), prehospital non-invasive ventilation (NIV) guided by arterial blood gas analysis has been shown to improve early physiological outcomes compared to standard medical treatment [123]. In the hospital, NIV can be delivered via Pressure Support Ventilation (PSV) or Adaptive Support Ventilation (ASV), with both modes showing similar feasibility in exploratory studies [38].
High-flow nasal oxygen (HFNO) is an alternative to NIV. The RENOVATE trial established that HFNO is noninferior to NIV regarding the rates of endotracheal intubation or death at 7 days in COPD patients with respiratory acidosis [9]. Furthermore, asymmetrical HFNC interfaces may reduce respiratory muscle work (diaphragm thickening fraction) more effectively than symmetrical interfaces at high flow rates (60 L/min) [122].
Special Considerations: Altitude and Medication Delivery
Patients with COPD (GOLD 1-2) traveling to high altitudes (3,100 m) are at risk for Acute Mountain Sickness (AMS). Dexamethasone (8 mg/d) significantly reduces the incidence of AMS and altitude-related adverse health effects in this population [34]. For medication delivery during NIV, vibrating mesh nebulizers (VMN) are more effective than jet nebulizers, providing superior pulmonary deposition of radiolabeled bronchodilators [33].
| Condition | Sensitivity | Specificity | Accuracy |
|---|---|---|---|
| Interstitial Lung Disease | 100% | 100% | 100% |
| Pleural Effusion | 100% | 100% | 100% |
| Pneumonia | 92.3% | 93.9% | 93.7% |
| COPD/Asthma | 87.5% | 96.8% | 94.9% |
Differential Diagnosis
- ▸Acute heart failure is a primary differential; POCUS and NT-proBNP are key diagnostic tools [60, 45].
- ▸Pulmonary embolism prevalence in unexplained AECOPD is approximately 16-25% [57, 129].
- ▸CRP and procalcitonin help differentiate AECOPD from comorbid pneumonia [128].
- ▸RSV and influenza are significant viral triggers with long-term morbidity [114].
- ▸Beta-blockers should generally be continued in COPD patients with heart failure or IHD [126].
- ▸Malnutrition significantly increases mortality risk; nutritional supplementation may improve outcomes [59].
The differential diagnosis of an acute exacerbation of COPD (AECOPD) is broad, as many acute respiratory and cardiovascular conditions present with similar symptoms of increased dyspnea, cough, and sputum production. Accurate differentiation is critical, as comorbid conditions frequently coexist and significantly impact clinical outcomes [58][61][124].
Cardiovascular Conditions
Acute heart failure (AHF) and acute cardiogenic pulmonary edema (ACPE) are the most frequent mimics and comorbidities of AECOPD [58][61].
- Diagnostic Differentiation: Bedside point-of-care ultrasound (POCUS) is highly effective; the presence of a 'comet-tail sign' (B-lines) suggests interstitial lung disease or pulmonary edema rather than isolated COPD [60][45]D. POCUS has demonstrated 100% sensitivity and specificity for diagnosing pleural effusion and interstitial lung disease in acute dyspnea [45]D. Additionally, N-terminal pro-brain natriuretic peptide (NT-proBNP) levels are significantly higher in AHF compared to AECOPD [60].
- MicroRNA Signatures: Research into circulating microRNAs (miRNAs) has shown that levels are decreased in AHF patients compared to healthy controls, whereas no significant changes in these specific miRNA levels were observed in patients with AECOPD [127].
- Clinical Impact: Patients with comorbid COPD and AHF are often older, have a higher burden of diabetes and hypertension, and face a higher risk of all-cause and respiratory-related readmission [61][125]C. Interestingly, while beta-blockers are sometimes withheld in COPD, evidence suggests they may improve survival in patients with underlying ischemic heart disease or heart failure even during an exacerbation [126].
Pulmonary Embolism (PE)
Pulmonary embolism is a critical differential, especially in 'unexplained' exacerbations where no clear infectious trigger is found [57].
- Prevalence: Systematic reviews indicate that PE may be present in approximately 16% to 25% of patients hospitalized with AECOPD [57][129].
- Clinical Presentation: PE should be suspected when dyspnea is out of proportion to clinical signs of airway obstruction. Long-term follow-up of PE patients shows that nearly 18.3% to 21.9% maintain abnormal functional capacity (measured by 6-minute walking distance) at 12 months post-event [71]D.
Infectious Mimics
- Pneumonia: Differentiating AECOPD from community-acquired pneumonia (CAP) is essential. Inflammatory markers such as C-reactive protein (CRP) and procalcitonin (PCT) are typically higher in patients with CAP+COPD compared to those with AECOPD alone [128]. The ratio of CRP to neopterin (NPT) has also been studied as a tool to distinguish these states [128].
- Respiratory Syncytial Virus (RSV) and Influenza: Viral infections are common triggers. Hospitalization for RSV-related acute respiratory illness in adults ≥50 years is associated with long-term risks of subsequent COPD exacerbations and heart failure hospitalizations, similar to or exceeding risks seen with influenza [114].
Other Considerations
- Malnutrition: Malnourished older adults (Subjective Global Assessment class B or C) hospitalized for AECOPD have a high risk of readmission. Specialized high-protein oral nutritional supplements containing beta-hydroxy-beta-methylbutyrate (HP-HMB) have been shown to reduce post-discharge mortality in this population [59].
- Medication Safety: In patients with ACPE and comorbid COPD, the use of midazolam for anxiety has been associated with fewer serious adverse events compared to morphine [58]. Furthermore, clinicians must be vigilant for potentially inappropriate medications (PIMs); studies show a high prevalence of PIMs in elderly patients hospitalized for AECOPD, which may complicate the clinical course [91]D.
- AI in Diagnosis: Emerging AI models can assist in diagnosing hospitalized patients, though clinicians must remain aware of potential systematic biases in these models that could affect diagnostic accuracy [32].
| Tool | AECOPD Findings | Acute Heart Failure Findings |
|---|---|---|
| POCUS | A-lines (normal lung sliding) | B-lines (comet-tail sign) [60][45]D |
| NT-proBNP | Low/Normal | Elevated [60] |
| miRNA | No significant change | Decreased levels [127] |
| CRP/PCT | Mildly elevated | Usually normal (unless pneumonia) [128] |
Management: Pharmacological Therapy
- ▸A 5-day course of systemic corticosteroids is non-inferior to a 14-day course for AECOPD management [81].
- ▸Procalcitonin levels <0.1 ng/ml identify patients who likely do not benefit from antibiotic therapy [75].
- ▸Vibrating mesh nebulizers provide better drug deposition than jet nebulizers during non-invasive ventilation [33].
- ▸Nebulized budesonide is an effective alternative to systemic methylprednisolone with fewer side effects [74].
- ▸Roflumilast reduces exacerbation frequency when added to LABA therapy in severe COPD [130].
- ▸Poor sleep quality (PSQI >5) is a significant predictor of COPD exacerbation risk [77].
Bronchodilator Therapy
Short-acting bronchodilators remain the cornerstone of management for acute exacerbations of COPD (AECOPD) [73]. While short-acting β2-agonists (SABA) are the primary treatment in the emergency department, the addition of short-acting anticholinergics like ipratropium bromide to terbutaline has been evaluated in hypercapnic patients requiring non-invasive ventilation (NIV); however, evidence suggests this combination may not significantly reduce hospital or ICU admission rates compared to terbutaline alone [73].
For delivery methods during NIV, vibrating mesh nebulizers (VMN) have demonstrated superior pulmonary deposition and distribution of radiolabeled aerosols compared to jet nebulizers (JN) [33]. In stable patients, long-acting bronchodilators such as tiotropium and salmeterol are used for prevention; tiotropium has been shown to be effective in reducing the risk of exacerbations and related hospitalizations [80]. The efficacy of these long-acting agents does not appear to be significantly influenced by ADRB2 polymorphisms (Arg16Gly and Gln27Glu) [78]. In the acute setting, the once-daily LABA indacaterol (150 μg or 300 μg) has been investigated for its rapid onset; while it provides bronchodilation, clinicians must monitor for transient decreases in PaO2, a known effect of β2-agonists that can be potentially dangerous during an exacerbation [79][84].
Corticosteroid Administration
Systemic corticosteroids improve clinical outcomes in AECOPD, but the optimal duration is a subject of significant clinical refinement. The REDUCE trial established that a short-term (5-day) course of systemic glucocorticoids (40 mg prednisone) is non-inferior to a conventional 14-day course regarding clinical outcomes and re-exacerbation rates, while significantly decreasing total steroid exposure [81]. In critically ill patients admitted to the ICU, retrospective data also support that short-course therapy (≤5 days) does not increase treatment failure (defined as need for intubation or NIV) compared to extended tapers [101]D.
Nebulized budesonide has emerged as a viable alternative to systemic methylprednisolone, offering similar clinical efficacy with a potentially reduced risk of systemic side effects [74]. For specific environmental triggers, dexamethasone (8 mg/d) has been shown to prevent acute mountain sickness and altitude-related adverse health effects in patients with GOLD grade 1-2 COPD traveling to high altitudes (3,100 m) [34].
Antibiotic Stewardship and Biomarkers
Procalcitonin (PCT) is a valuable biomarker for guiding antibiotic therapy in AECOPD. In patients with low serum PCT values (<0.1 ng/ml), studies indicate no significant benefit from antibiotic treatment, suggesting that antibiotics can be safely withheld in these cases [75]. In the ICU setting, using a PCT-based algorithm to guide the initiation or cessation of antibiotics was found to be non-inferior to standard therapy regarding 3-month mortality, potentially reducing unnecessary antibiotic exposure [35].
Adjunctive Therapies and Long-term Management
Phosphodiesterase-4 (PDE4) inhibitors, specifically roflumilast (500 μg), significantly reduce the risk of exacerbations when added to long-acting β2-agonists (LABA) in patients with severe COPD and a history of frequent exacerbations [130]. Nutritional status is a critical prognostic factor; in malnourished hospitalized older adults (SGA class B or C), a high-protein oral nutritional supplement containing beta-hydroxy-beta-methylbutyrate (HP-HMB) has been evaluated to improve post-discharge outcomes [59].
Other factors influencing exacerbation risk include sleep quality, with poor sleep (Pittsburgh Sleep Quality Index >5) serving as a predictor for future exacerbation events [77]. While vitamin D and marine omega-3 fatty acids are under investigation for their role in reducing respiratory exacerbations, definitive large-scale trial results are pending [76]. Finally, physical interventions such as exercise using a pedal exerciser during hospitalization can reduce disability by improving muscle strength and balance in frail older patients [82].
| Strategy | Duration | Evidence Level | Clinical Outcome |
|---|---|---|---|
| Short-course (REDUCE) | 5 Days | 1b | Non-inferior to 14 days; reduced steroid load [81] |
| Conventional | 14 Days | 1b | Standard guideline duration [81] |
| Nebulized Budesonide | Variable | 1b | Similar efficacy to systemic methylprednisolone [74] |
| ICU Taper | ≤5 Days | 4 | No increase in treatment failure vs >5 days [101]D |
Management: Respiratory Support
- ▸NIV is the first-line treatment for AHRF in COPD, with a target initiation time of < 60 minutes.
- ▸HFNO is clinically noninferior to NIV for COPD exacerbations and offers a more cost-effective profile.
- ▸Weak cough (SCSS ≤ 3) and malnutrition (protein ≤ 58 g/L) are major predictors of NIV failure.
- ▸Vibrating mesh nebulizers are more effective than jet nebulizers for bronchodilator delivery during NIV.
- ▸Short-course corticosteroids (≤ 5 days) are sufficient for most critically ill COPD patients on ventilation.
- ▸Persistent acidosis (pH < 7.30) at 2 hours does not always necessitate intubation if clinical improvement is present.
Non-Invasive Ventilation (NIV)
Non-invasive ventilation remains the first-line respiratory support modality for patients with acute hypercapnic respiratory failure (AHRF) due to COPD exacerbation [131]. While clinical practice often mirrors randomized trial findings, real-world data suggests that timely application is critical; national audits indicate that while overall mortality has decreased, the proportion of patients receiving NIV within 60 minutes of admission has declined, potentially impacting outcomes [97]D.
Models of Care and Settings
NIV can be successfully implemented across various hospital settings, including general wards, high-dependency units (HDU), and intensive care units (ICU). A prospective study found no significant difference in clinical outcomes between these models when corrected for disease severity, suggesting that a general ward with a 1:4 nurse-to-patient ratio may be non-inferior to more intensive settings for appropriate patients [100]D. Furthermore, NIV has been shown to be feasible and effective in general medical wards even for patients with severe respiratory acidosis (pH < 7.26), provided the staff is experienced [132]C. In the prehospital setting, NIV guided by arterial blood gas analysis has been investigated to improve early physiological outcomes, though logistical constraints remain a challenge [123].
Predictors of Success and Failure
NPPV failure (defined as the need for endotracheal intubation or death) occurs in approximately 21.1% of cases [105]D. Key independent risk factors for failure include:
- Weak cough strength: A semiquantitative cough strength score (SCSS) ≤ 3 [105]D.
- High disease severity: APACHE II score > 19 [105]D.
- Malnutrition: Total protein levels ≤ 58 g/L [105]D.
- Anemia: The presence of anemia is an independent predictor of mortality in patients requiring NIV for AHRF [95].
- Functional Status: Lower gait speed at discharge is associated with higher rates of readmission or death [50]D.
Notably, a "delayed response"—where severe respiratory acidosis (pH < 7.30) persists after the first 2 hours of NIV—does not necessarily mandate immediate intubation if other clinical improvements are noted, as many of these patients eventually stabilize [102]D.
Ventilation Modes and Adjuncts
While Pressure Support Ventilation (PSV) is standard, Adaptive Support Ventilation (ASV) is a feasible alternative with similar rates of NIV failure and patient comfort [38]. During NIV, the delivery of bronchodilators is more efficient when using a vibrating mesh nebulizer (VMN) compared to a standard jet nebulizer, resulting in superior pulmonary deposition [33].
High-Flow Nasal Oxygen (HFNO)
High-flow nasal oxygen (HFNO) is increasingly utilized as an alternative to NIV. The RENOVATE trial established that HFNO is noninferior to NIV regarding the rates of endotracheal intubation or death at 7 days in COPD patients with respiratory acidosis [9]. From an economic perspective, HFNO is associated with lower direct costs compared to NIV, primarily due to reduced equipment and monitoring requirements, supporting its use in cost-minimization strategies [8].
Recent interface innovations include asymmetrical HFNC, which has been shown to reduce respiratory muscle work of breathing (measured via diaphragm thickening fraction) similarly to conventional symmetrical interfaces in COPD patients [122].
Invasive Mechanical Ventilation and Prognosis
Invasive ventilation is reserved for patients failing NIV or those with immediate contraindications. In critically ill patients, the duration of corticosteroid therapy remains debated; however, evidence suggests that a short course (≤ 5 days) is as effective as extended tapers in preventing treatment failure (reintubation or NIV reinstitution) [101]D. Comorbidities significantly influence outcomes; for instance, in patients with concomitant COVID-19, age and male sex are strong predictors of adverse prognosis and the need for mechanical ventilation [7]. In patients with acute heart failure complicating COPD, the early use of NIV in the emergency department has been associated with improved 30-day survival [99]D.
| Risk Factor | Threshold/Criteria | Odds Ratio for Failure |
|---|---|---|
| Cough Strength | SCSS ≤ 3 | 8.1 |
| Disease Severity | APACHE II > 19 | 3.8 |
| Nutritional Status | Total Protein ≤ 58 g/L | 2.8 |
| Acidosis | pH < 7.30 after 2h | Variable (Delayed Response) |
Prognosis and Long-term Outcomes
- ▸In-hospital mortality in AECOPD is strongly predicted by frailty, age ≥80, and low albumin levels.
- ▸Suboptimal peak inspiratory flow (≤60 L/min) is a major risk factor for 30-day and 90-day readmission.
- ▸Gait speed at hospital discharge is a simple but effective predictor of death or readmission in AHRF survivors.
- ▸Viral infections, particularly RSV and rhinovirus, significantly complicate the prognosis of severe AECOPD.
- ▸Delayed response to NIV (persistent acidosis at 2 hours) does not necessarily indicate treatment failure if clinical improvement occurs within 48 hours.
- ▸COPD patients are at increased risk for adverse outcomes when hospitalized for COVID-19 or heart failure.
Mortality and In-Hospital Outcomes
Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are associated with significant in-hospital mortality and long-term morbidity. In older populations (aged ≥80 years), predictors of in-hospital mortality include lower albumin levels, higher blood urea nitrogen (BUN), and lower functional status as measured by the Activities of Daily Living (ADL) Hierarchy scale [112]D. Frailty is a critical independent prognostic factor; older patients with frailty exhibit significantly higher in-hospital mortality rates, a relationship that may be partially mediated by laboratory indicators [39].
Respiratory viral infections are detected in approximately 41.2% of severe AECOPD cases requiring hospitalization, with rhinovirus being the most common [29]D. The presence of viral infection, particularly when associated with higher C-reactive protein (CRP) levels, is linked to worse clinical outcomes [29]D. Furthermore, patients hospitalized for respiratory syncytial virus (RSV)-related acute respiratory illness (ARI) face a higher risk of subsequent COPD exacerbations and all-cause mortality compared to those without ARI [114]. In the context of the COVID-19 pandemic, COPD has been identified as a significant predictor of adverse composite outcomes, including ICU admission and mechanical ventilation [7].
Readmission Risks and Functional Predictors
Hospital readmission is a frequent and costly complication of AECOPD. The 30-day and 90-day readmission rates are influenced by both clinical and functional parameters. Suboptimal peak inspiratory flow (sPIF), defined as ≤60 L/min, is significantly associated with higher rates of both COPD-specific and all-cause readmissions, as it impairs the effective delivery of medications via dry powder inhalers (DPIs) [133].
Functional mobility at the time of discharge is a potent predictor of long-term stability. Patients surviving acute hypercapnic respiratory failure (AHRF) who exhibit slower gait speeds at discharge have a higher risk of death or readmission [50]D. Comorbidities also play a major role; for instance, patients hospitalized for heart failure who have comorbid COPD have a higher burden of respiratory-related readmissions compared to those without COPD [61]. Interestingly, while Medicare's Hospital Readmissions Reduction Program (HRRP) provides financial incentives to reduce readmissions, hospitals appear more responsive to aggregate penalty amounts than to condition-specific incentives [111]D.
Impact of Respiratory Support and Pharmacotherapy
The choice of respiratory support significantly influences short-term prognosis. Non-invasive ventilation (NIV) remains the first-line modality for acute respiratory failure (ARF) in AECOPD [131]. While early response to NIV is typical, a "delayed response"—defined as clinical improvement within 48 hours despite persistent severe respiratory acidosis (pH <7.30) after the first 2 hours—can still lead to successful outcomes in over 50% of cases [102]D. High-flow nasal oxygen (HFNO) has been evaluated as a noninferior alternative to NIV regarding intubation or death at 7 days across various ARF groups, including COPD [9].
In the emergency department (ED) setting, the use of NIV for patients with concomitant acute heart failure and COPD has shown benefits in short-term survival [99]D. Prehospital initiation of NIV guided by arterial blood gas analysis has also been explored to improve early physiological outcomes, though logistical constraints remain [123]. Regarding ventilation modes, adaptive support ventilation (ASV) appears to be a feasible alternative to pressure support ventilation (PSV) during NIV, with similar rates of treatment failure [38].
Pharmacological interventions during the acute phase also impact recovery. While short-course corticosteroid regimens (≤5 days) are generally as effective as extended tapers in critically ill patients, dosing strategies remain variable [101]D. For patients with COPD traveling to high altitudes (3,100 m), dexamethasone (8 mg/d) has been shown to reduce the incidence of altitude-related adverse health effects [34]. Additionally, herbal combinations such as HL301 have demonstrated efficacy in reducing Bronchitis Severity Scores (BSS) in patients with acute exacerbations of chronic bronchitis [109].
| Category | Predictor | Impact on Outcome |
|---|---|---|
| Functional | Gait Speed (Slow) | Increased death/readmission [50]D |
| Functional | sPIF ≤60 L/min | Higher 30/90-day readmission [133] |
| Clinical | Frailty | Higher in-hospital mortality [39] |
| Clinical | Age ≥80 years | Higher mortality, need for post-acute care [112]D |
| Laboratory | Low Albumin / High BUN | Increased in-hospital death [112]D |
| Comorbidity | Heart Failure | Increased respiratory-related readmission [61] |
Guidelines and Resources
- ▸AECOPD is characterized by irreversible airflow limitation and dynamic pulmonary hyperinflation, requiring specialized ventilation strategies [113].
- ▸The Chinese Society of Critical Care Medicine uses a modified Delphi criteria (Grades A-E) for mechanical ventilation guidelines [113].
- ▸Antibiotic use in COPD reactivations should be rationalized to prevent resistance, focusing on high-risk groups and those with significant co-morbidities [87].
- ▸Diagnosis of AECOPD is primarily clinical and must be distinguished from acute bronchitis and community-acquired pneumonia [87].
- ▸Rational use of diagnostic resources is a core tenet of modern inter-society consensus guidelines [87].
International and Regional Consensus Guidelines
The management of Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) is governed by evidence-based protocols designed to standardize care and improve clinical outcomes. Recent updates from the Chinese Society of Critical Care Medicine and the Argentine Society for Infectious Diseases emphasize the need for rational resource utilization and specialized ventilation strategies [113][87].
Mechanical Ventilation Strategies (2007 Chinese Guidelines)
Mechanical ventilation in AECOPD requires a distinct approach compared to other respiratory failures due to the underlying pathophysiology of irreversible airflow limitation and dynamic pulmonary hyperinflation [113]. The Chinese Society of Critical Care Medicine developed a comprehensive guideline using a modified Delphi criteria, categorizing evidence into five grades (A through E) to optimize clinical results [113].
Key considerations for mechanical ventilation in AECOPD include:
- Dynamic Hyperinflation Management: Strategies must account for the increased risk of intrinsic positive end-expiratory pressure (PEEPi) and its impact on hemodynamics and lung injury [113].
- Categorization of Evidence: The guidelines utilize a hierarchy where Grade A represents the highest level of clinical certainty, ensuring that ventilation parameters are based on robust clinical trials [113].
- Clinical Goal: The primary objective is to bridge the patient through the acute phase of respiratory failure while minimizing ventilator-associated complications [113].
Management of Respiratory Infections and Antibiotic Stewardship
Intersociety consensus guidelines, such as those issued by the Argentine Society for Infectious Diseases, provide frameworks for the management of COPD reactivations and acute bronchitis [87]. These guidelines aim to promote the rational use of diagnostic and therapeutic resources to combat antibiotic resistance and improve patient safety [87].
Diagnostic Criteria and Definitions
AECOPD (or reactivation) is defined as a sustained worsening of the patient's condition from the stable state, which is beyond normal day-to-day variations and is acute in onset [87]. It is critical to differentiate this from acute bronchitis (AB), which occurs in patients without underlying pulmonary disease and is typically viral in origin [87].
Antibiotic Indications
While AB is generally treated symptomatically, antibiotics are specifically indicated in AECOPD when certain criteria are met to ensure efficacy and prevent overuse [87]. High-risk groups requiring careful management include:
- Immune-compromised hosts [87].
- Patients with chronic respiratory or cardiac diseases [87].
- Elderly patients presenting with significant co-morbidities [87].
Rational Resource Utilization
Both guidelines emphasize that the diagnosis of AECOPD should be clinical, often requiring the exclusion of community-acquired pneumonia (CAP) through appropriate imaging and physical examination [87]. The goal of these resources is to provide clinicians with practical, updated tools to manage the high morbidity and mortality associated with COPD globally [113][87].
| Guideline Source | Focus Area | Evidence Grading System | Key Objective |
|---|---|---|---|
| Chinese Society of Critical Care Medicine [113] | Mechanical Ventilation | Modified Delphi (Grades A-E) | Improve clinical results in AECOPD ventilation |
| Argentine Society for Infectious Diseases [87] | Respiratory Infections | Intersociety Consensus | Rational use of diagnostic/therapeutic resources |
References
- [1]
Effing TW, Kerstjens HAM, Monninkhof EM et al.. “Definitions of exacerbations: does it really matter in clinical trials on COPD?” Chest (2009). PMID: 19736196 ↗
L2bTRIAL_NONRANDOMCited in: Definition, Synonyms, and Classification - [2]
Gandhi A, Walsh EE, Formica MA et al.. “Factors associated with symptomatic rhinovirus infection in patients with COPD.” Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology (2012). PMID: 22999488 ↗
L5OTHERCited in: Definition, Synonyms, and Classification - [3]
Soler-Cataluña JJ, Martínez-García MÁ, Serra PC. “[Multidimensional impact of COPD exacerbations].” Archivos de bronconeumologia (2010). PMID: 21316556 ↗
L5REVIEW_NARRATIVECited in: Definition, Synonyms, and Classification - [4]
Huang T, Xu Z, Xu A et al.. “In-depth comparative pathogenome, virulome, and resistome analysis of an extensive drug resistant Ralstonia mannitolilytica strain isolated from blood.” Microbial pathogenesis (2024). PMID: 39306054 ↗
L5OTHERCited in: Definition, Synonyms, and Classification - [5]
Makris D, Bouros D. “COPD exacerbation: lost in translation.” BMC pulmonary medicine (2009). PMID: 19178701 ↗
L5OTHERCited in: Definition, Synonyms, and Classification - [6]
Su J, Liu HY, Tan XL et al.. “Sputum Bacterial and Fungal Dynamics during Exacerbations of Severe COPD.” PloS one (2015). PMID: 26147303 ↗
L5OTHERCited in: Definition, Synonyms, and Classification - [7]
Figliozzi S, Masci PG, Ahmadi N et al.. “Predictors of adverse prognosis in COVID-19: A systematic review and meta-analysis.” European journal of clinical investigation (2020). PMID: 32726868 ↗
L2aSR_OBSCited in: Etiology and Triggering Factors, Diagnosis and Workup, Management: Pharmacological Therapy, Management: Respiratory Support, Prognosis and Long-term Outcomes - [8]
Beck da Silva Etges AP, Marcolino MAZ, Bianchini L et al.. “Economic analysis of high-flow nasal oxygen compared with noninvasive ventilation in patients with acute respiratory failure: results from the RENOVATE randomized clinical trial.” Respiratory medicine (2025). PMID: 40744283 ↗
L1bRCTCited in: Etiology and Triggering Factors, Management: Respiratory Support - [9]
Maia IS, Kawano-Dourado L, Tramujas L et al.. “High-Flow Nasal Oxygen vs Noninvasive Ventilation in Patients With Acute Respiratory Failure: The RENOVATE Randomized Clinical Trial.” JAMA (2025). PMID: 39657981 ↗
L1bRCTCited in: Etiology and Triggering Factors, Diagnosis and Workup, Management: Respiratory Support, Prognosis and Long-term Outcomes - [10]
Pasqua F, Biscione G, Crigna G et al.. “Prulifloxacin in the treatment of acute exacerbations of COPD in cigarette smokers.” Therapeutic advances in respiratory disease (2008). PMID: 19124373 ↗
L2bTRIAL_NONRANDOMCited in: Etiology and Triggering Factors - [11]
Cintora-Sanz AM, Horrillo-García C, Quesada-Cubo V et al.. “Prevalence and Economic Impact of Acute Respiratory Failure in the Prehospital Emergency Medical Service of the Madrid Community: Retrospective Cohort Study.” JMIR public health and surveillance (2025). PMID: 39819841 ↗
L2bCOHORTCited in: Etiology and Triggering Factors - [12]
Ko FW, Ip M, Chan PK et al.. “A one-year prospective study of infectious etiology in patients hospitalized with acute exacerbations of COPD and concomitant pneumonia.” Respiratory medicine (2008). PMID: 18573648 ↗
L2bCOHORTCited in: Etiology and Triggering Factors - [13]
van Geffen WH, Bruins M, Kerstjens HA. “Diagnosing viral and bacterial respiratory infections in acute COPD exacerbations by an electronic nose: a pilot study.” Journal of breath research (2016). PMID: 27310311 ↗
L2bTRIAL_NONRANDOMCited in: Etiology and Triggering Factors - [14]
Nishimura K, Nishimura T, Oga T. “Streptococcus pneumoniae urinary antigen test and acute exacerbations of chronic obstructive pulmonary disease.” COPD (2012). PMID: 22452423 ↗
L2bTRIAL_NONRANDOMCited in: Etiology and Triggering Factors - [15]
Menon B, Gurnani M, Aggarwal B. “Comparison of outpatient visits and hospitalisations, in patients with chronic obstructive pulmonary disease, before and after influenza vaccination.” International journal of clinical practice (2008). PMID: 18284444 ↗
L2bTRIAL_NONRANDOMCited in: Etiology and Triggering Factors - [16]
Clancy RL, Cripps AW. “An Oral Whole-Cell Killed Nontypeable Haemophilus influenzae Immunotherapeutic For The Prevention Of Acute Exacerbations Of Chronic Airway Disease.” International journal of chronic obstructive pulmonary disease (2019). PMID: 31695359 ↗
L5REVIEW_NARRATIVECited in: Etiology and Triggering Factors, Management: Pharmacological Therapy - [17]
Leung JM, Tiew PY, Mac Aogáin M et al.. “The role of acute and chronic respiratory colonization and infections in the pathogenesis of COPD.” Respirology (Carlton, Vic.) (2017). PMID: 28342288 ↗
L5REVIEW_NARRATIVECited in: Etiology and Triggering Factors - [18]
Ritchie AI, Farne HA, Singanayagam A et al.. “Pathogenesis of Viral Infection in Exacerbations of Airway Disease.” Annals of the American Thoracic Society (2015). PMID: 26595727 ↗
L5REVIEW_NARRATIVECited in: Etiology and Triggering Factors - [19]
Sasaki T, Nakayama K, Yasuda H et al.. “A new strategy with proton pump inhibitors for the prevention of acute exacerbations in COPD.” Therapeutic advances in respiratory disease (2011). PMID: 21285157 ↗
L5REVIEW_NARRATIVECited in: Etiology and Triggering Factors - [20]
Papaetis GS, Anastasakou E, Orphanidou D. “Chlamydophila pneumoniae infection and COPD: more evidence for lack of evidence?” European journal of internal medicine (2009). PMID: 19782917 ↗
L5REVIEW_NARRATIVECited in: Etiology and Triggering Factors - [21]
Cazzola M, Rogliani P, Curradi G. “Bacterial extracts for the prevention of acute exacerbations in chronic obstructive pulmonary disease: a point of view.” Respiratory medicine (2008). PMID: 18164190 ↗
L5REVIEW_NARRATIVECited in: Etiology and Triggering Factors - [22]
Hutchinson AF, Ghimire AK, Thompson MA et al.. “A community-based, time-matched, case-control study of respiratory viruses and exacerbations of COPD.” Respiratory medicine (2007). PMID: 17822891 ↗
L3bCASE_CONTROLCited in: Etiology and Triggering Factors - [23]
Greenberg SB. “Rhinovirus and coronavirus infections.” Seminars in respiratory and critical care medicine (2007). PMID: 17458772 ↗
L5REVIEW_NARRATIVECited in: Etiology and Triggering Factors - [24]
Footitt J, Johnston SL. “Cough and viruses in airways disease: mechanisms.” Pulmonary pharmacology & therapeutics (2009). PMID: 19480062 ↗
L5REVIEW_NARRATIVECited in: Etiology and Triggering Factors - [25]
Black PN, McDonald CF. “Interventions to reduce the frequency of exacerbations of chronic obstructive pulmonary disease.” Postgraduate medical journal (2009). PMID: 19351641 ↗
L5REVIEW_NARRATIVECited in: Etiology and Triggering Factors - [26]
Chen CYJ, Yew MS, Abisheganaden JA et al.. “Predictors of Influenza PCR Positivity in Acute Exacerbations of Chronic Obstructive Pulmonary Disease.” International journal of chronic obstructive pulmonary disease (2022). PMID: 35023911 ↗
L5OTHERCited in: Etiology and Triggering Factors, Diagnosis and Workup - [27]
Oliveira A, Quach S, Alsubheen S et al.. “Rapid access rehabilitation after exacerbations of COPD - A qualitative study.” Respiratory medicine (2021). PMID: 34260976 ↗
L5OTHERCited in: Etiology and Triggering Factors, Diagnosis and Workup, Prognosis and Long-term Outcomes - [28]
Schneider CV, Strnad P. “SARS-CoV-2 infection in alpha1-antitrypsin deficiency.” Respiratory medicine (2021). PMID: 34010739 ↗
L5OTHERCited in: Etiology and Triggering Factors - [29]
Jang JG, Ahn JH, Jin HJ. “Incidence and Prognostic Factors of Respiratory Viral Infections in Severe Acute Exacerbation of Chronic Obstructive Pulmonary Disease.” International journal of chronic obstructive pulmonary disease (2021). PMID: 33994783 ↗
L5OTHERCited in: Etiology and Triggering Factors, Diagnosis and Workup, Prognosis and Long-term Outcomes - [30]
Nolen LD, Seeman S, Desnoyers C et al.. “Respiratory syncytial virus and influenza hospitalizations in Alaska native adults.” Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology (2020). PMID: 32334281 ↗
L5OTHERCited in: Etiology and Triggering Factors - [31]
Dauchy C, Bautin N, Nseir S et al.. “Emergence of Aspergillus fumigatus azole resistance in azole-naïve patients with chronic obstructive pulmonary disease and their homes.” Indoor air (2018). PMID: 29082624 ↗
L5OTHERCited in: Etiology and Triggering Factors - [32]
Jabbour S, Fouhey D, Shepard S et al.. “Measuring the Impact of AI in the Diagnosis of Hospitalized Patients: A Randomized Clinical Vignette Survey Study.” JAMA (2023). PMID: 38112814 ↗
L1bRCTCited in: Diagnosis and Workup, Differential Diagnosis - [33]
Galindo-Filho VC, Alcoforado L, Rattes C et al.. “A mesh nebulizer is more effective than jet nebulizer to nebulize bronchodilators during non-invasive ventilation of subjects with COPD: A randomized controlled trial with radiolabeled aerosols.” Respiratory medicine (2019). PMID: 31170543 ↗
L1bRCTCited in: Diagnosis and Workup, Management: Pharmacological Therapy, Management: Respiratory Support - [34]
Furian M, Lichtblau M, Aeschbacher SS et al.. “Efficacy of Dexamethasone in Preventing Acute Mountain Sickness in COPD Patients: Randomized Trial.” Chest (2018). PMID: 29909285 ↗
L1bRCTCited in: Diagnosis and Workup, Management: Pharmacological Therapy, Prognosis and Long-term Outcomes - [35]
Daubin C, Valette X, Thiollière F et al.. “Procalcitonin algorithm to guide initial antibiotic therapy in acute exacerbations of COPD admitted to the ICU: a randomized multicenter study.” Intensive care medicine (2018). PMID: 29663044 ↗
L1bRCTCited in: Diagnosis and Workup, Management: Pharmacological Therapy - [36]
Jaeger D, Duchanois C, Duarte K et al.. “Performance of an ultrasound diagnostic algorithm for acute dyspneic patients in the emergency department: an EMERALD-US protocol.” BMJ open (2025). PMID: 40784781 ↗
L2bTRIAL_NONRANDOMCited in: Diagnosis and Workup, Differential Diagnosis - [37]
Jin J, Zhang H, Li D et al.. “Effectiveness of Xin Jia Xuan Bai Cheng Qi Decoction in treating acute exacerbation of chronic obstructive pulmonary disease: study protocol for a multicentre, randomised, controlled trial.” BMJ open (2019). PMID: 31784433 ↗
L2bTRIAL_NONRANDOMCited in: Diagnosis and Workup, Prognosis and Long-term Outcomes - [38]
Sehgal IS, Kalpakam H, Dhooria S et al.. “A Randomized Controlled Trial of Noninvasive Ventilation with Pressure Support Ventilation and Adaptive Support Ventilation in Acute Exacerbation of COPD: A Feasibility Study.” COPD (2019). PMID: 31161812 ↗
L1bRCTCited in: Diagnosis and Workup, Management: Respiratory Support, Prognosis and Long-term Outcomes - [39]
Li L, Wang L, Zhang L et al.. “Frailty and in-hospital mortality in older patients with acute exacerbation of COPD: A real-world prospective cohort study.” Respiratory medicine (2024). PMID: 38763445 ↗
L2bCOHORTCited in: Diagnosis and Workup, Prognosis and Long-term Outcomes - [40]
Cortegiani A, Longhini F, Carlucci A et al.. “High-flow nasal therapy versus noninvasive ventilation in COPD patients with mild-to-moderate hypercapnic acute respiratory failure: study protocol for a noninferiority randomized clinical trial.” Trials (2019). PMID: 31331372 ↗
L2bTRIAL_NONRANDOMCited in: Diagnosis and Workup, Management: Respiratory Support, Prognosis and Long-term Outcomes - [41]
Zhen G, Jing J, Fengsen L. “Traditional Chinese medicine classic herbal formula Xiaoqinglong decoction for acute exacerbation of chronic obstructive pulmonary disease: A systematic review protocol.” Medicine (2018). PMID: 30593152 ↗
L2aSR_OBSCited in: Diagnosis and Workup, Prognosis and Long-term Outcomes - [42]
Hu WP, Lhamo T, Zhang FY et al.. “Predictors of acute cardiovascular events following acute exacerbation period for patients with COPD: a nested case-control study.” BMC cardiovascular disorders (2020). PMID: 33302869 ↗
L3bCASE_CONTROLCited in: Diagnosis and Workup, Prognosis and Long-term Outcomes - [43]
Gloeckl R, Jones PW, Kroll D et al.. “Can Patient Education Lead the Way? Head-To-Head Comparison of EXACT and CERT for Early Recognition of Acute COPD Exacerbations.” Respirology (Carlton, Vic.) (2026). PMID: 41320645 ↗
L5OTHERCited in: Diagnosis and Workup - [44]
Pillai S, Lawrence M, Zaldua JC et al.. “Alterations in clot microstructure in acute exacerbations of COPD.” Respiratory research (2025). PMID: 41254616 ↗
L5OTHERCited in: Diagnosis and Workup - [45]
Hamza Yousef MS, Al Azizi HM, Fouad MM. “Point of care ultrasound as a bedside diagnostic tool in acute dyspnea patients in emergency department for timely management.” Respiratory medicine (2025). PMID: 41237919 ↗
L5OTHERCited in: Diagnosis and Workup, Differential Diagnosis - [46]
Welch C, Bravo L, Gkoutos G et al.. “Establishing Predictors of Acute Sarcopenia: A Proof-Of-Concept Study Utilising Network Analysis.” Aging and disease (2024). PMID: 39012665 ↗
L5OTHERCited in: Diagnosis and Workup - [47]
Echevarria C, Steer J, Prasad A et al.. “Admission blood eosinophil count, inpatient death and death at 1 year in exacerbating patients with COPD.” Thorax (2023). PMID: 37487711 ↗
L5OTHERCited in: Diagnosis and Workup, Management: Pharmacological Therapy - [48]
Zhang Y, Ren L, Sun J et al.. “Increased Serum Soluble Interleukin-2 Receptor Associated with Severity of Acute Exacerbation of Chronic Obstructive Pulmonary Disease.” International journal of chronic obstructive pulmonary disease (2021). PMID: 34522094 ↗
L5OTHERCited in: Diagnosis and Workup, Prognosis and Long-term Outcomes - [49]
Peng L, Han L, Li XN et al.. “The Predictive Value of microRNA-134 and microRNA-1233 for the Early Diagnosis of Acute Exacerbation of Chronic Obstructive Pulmonary Disease with Acute Pulmonary Embolism.” International journal of chronic obstructive pulmonary disease (2020). PMID: 33116466 ↗
L5OTHERCited in: Diagnosis and Workup, Differential Diagnosis - [50]
Karege G, Zekry D, Allali G et al.. “Gait speed is associated with death or readmission among patients surviving acute hypercapnic respiratory failure.” BMJ open respiratory research (2020). PMID: 32561512 ↗
L5OTHERCited in: Diagnosis and Workup, Management: Respiratory Support, Prognosis and Long-term Outcomes - [51]
Miró Ò, Takagi K, Gayat E et al.. “CORT-AHF Study: Effect on Outcomes of Systemic Corticosteroid Therapy During Early Management Acute Heart Failure.” JACC. Heart failure (2019). PMID: 31521676 ↗
L5OTHERCited in: Diagnosis and Workup, Management: Pharmacological Therapy, Prognosis and Long-term Outcomes - [52]
Pulido Herrero E, García Gutiérrez S, Antón Ladislao A et al.. “Chronic obstructive pulmonary disease assessment test: usefulness for monitoring recovery and predicting poor course of disease after exacerbations.” Emergencias : revista de la Sociedad Espanola de Medicina de Emergencias (2019). PMID: 30656869 ↗
L2bTRIAL_NONRANDOMCited in: Diagnosis and Workup, Prognosis and Long-term Outcomes - [53]
Suzuki S, Yoshihisa A, Sato Y et al.. “Clinical Significance of Get With the Guidelines-Heart Failure Risk Score in Patients With Chronic Heart Failure After Hospitalization.” Journal of the American Heart Association (2018). PMID: 30371158 ↗
L5OTHERCited in: Diagnosis and Workup - [54]
Ladjemi MZ, Martin C, Lecocq M et al.. “Increased IgA Expression in Lung Lymphoid Follicles in Severe Chronic Obstructive Pulmonary Disease.” American journal of respiratory and critical care medicine (2019). PMID: 30339768 ↗
L5OTHERCited in: Diagnosis and Workup - [55]
Labaki WW, Xia M, Murray S et al.. “NT-proBNP in stable COPD and future exacerbation risk: Analysis of the SPIROMICS cohort.” Respiratory medicine (2018). PMID: 29957287 ↗
L5OTHERCited in: Diagnosis and Workup - [56]
Oliveira A, Rodrigues J, Marques A. “Enhancing our understanding of computerised adventitious respiratory sounds in different COPD phases and healthy people.” Respiratory medicine (2018). PMID: 29724394 ↗
L5OTHERCited in: Diagnosis and Workup - [57]
Aleva FE, Voets LWLM, Simons SO et al.. “Prevalence and Localization of Pulmonary Embolism in Unexplained Acute Exacerbations of COPD: A Systematic Review and Meta-analysis.” Chest (2017). PMID: 27522956 ↗
L2aSR_OBSCited in: Differential Diagnosis - [58]
Domínguez-Rodríguez A, Hernandez-Vaquero D, Suero-Mendez C et al.. “Effects of MIdazolam versus MOrphine in acute cardiogenic pulmonary edema and chronic obstructive pulmonary disease: An analysis of MIMO trial.” The American journal of emergency medicine (2023). PMID: 37703629 ↗
L1bRCTCited in: Differential Diagnosis - [59]
Deutz NE, Matheson EM, Matarese LE et al.. “Readmission and mortality in malnourished, older, hospitalized adults treated with a specialized oral nutritional supplement: A randomized clinical trial.” Clinical nutrition (Edinburgh, Scotland) (2016). PMID: 26797412 ↗
L1bRCTCited in: Differential Diagnosis, Management: Pharmacological Therapy - [60]
Prosen G, Klemen P, Štrnad M et al.. “Combination of lung ultrasound (a comet-tail sign) and N-terminal pro-brain natriuretic peptide in differentiating acute heart failure from chronic obstructive pulmonary disease and asthma as cause of acute dyspnea in prehospital emergency setting.” Critical care (London, England) (2011). PMID: 21492424 ↗
L2bTRIAL_NONRANDOMCited in: Differential Diagnosis - [61]
Gulea C, Zakeri R, Quint JK. “Impact of chronic obstructive pulmonary disease on readmission after hospitalization for acute heart failure: A nationally representative US cohort study.” International journal of cardiology (2019). PMID: 31101544 ↗
L2bCOHORTCited in: Differential Diagnosis, Prognosis and Long-term Outcomes - [62]
Cao YQ, Dong LX, Cao J. “Pulmonary Embolism in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease.” Chinese medical journal (2018). PMID: 29998894 ↗
L5REVIEW_NARRATIVECited in: Differential Diagnosis - [63]
Neesse A, Jerrentrup A, Hoffmann S et al.. “Prehospital chest emergency sonography trial in Germany: a prospective study.” European journal of emergency medicine : official journal of the European Society for Emergency Medicine (2012). PMID: 21817908 ↗
L2bCOHORTCited in: Differential Diagnosis - [64]
Fu X, Zhong Y, Xu W et al.. “The prevalence and clinical features of pulmonary embolism in patients with AE-COPD: A meta-analysis and systematic review.” PloS one (2021). PMID: 34473738 ↗
L2aSR_OBSCited in: Differential Diagnosis - [65]
Ege MR, Guray U, Guray Y et al.. “Acute heart failure with accompanying chronic obstructive pulmonary disease: should we focus on beta blockers?” Herz (2012). PMID: 22699995 ↗
L2bTRIAL_NONRANDOMCited in: Differential Diagnosis - [66]
Nakamura K, Alba GA, Scheske JA et al.. “A 57-Year-Old Man With Insidious Dyspnea and Nonpleuritic Chest and Back Pain.” Chest (2016). PMID: 27502992 ↗
L4CASE_REPORTCited in: Differential Diagnosis - [67]
Mantuani D, Nagdev A. “Three-view bedside ultrasound to differentiate acute decompensated heart failure from chronic obstructive pulmonary disease.” The American journal of emergency medicine (2013). PMID: 23380088 ↗
L4CASE_REPORTCited in: Differential Diagnosis - [68]
Bertoletti L, Couturaud F, Sanchez O et al.. “Pulmonary Embolism and Chronic Obstructive Pulmonary Disease.” Seminars in thrombosis and hemostasis (2023). PMID: 36108648 ↗
L5REVIEW_NARRATIVECited in: Differential Diagnosis - [69]
Hüfner A, Dodt C. “[Ermergency diagnostics and therapeutic management of acute dyspnea].” Medizinische Klinik, Intensivmedizin und Notfallmedizin (2015). PMID: 26407960 ↗
L5REVIEW_NARRATIVECited in: Differential Diagnosis - [70]
Hüfner A, Dodt C. “[Definition, primary examination and differential diagnostics in acute dyspnea].” Medizinische Klinik, Intensivmedizin und Notfallmedizin (2015). PMID: 26335293 ↗
L5REVIEW_NARRATIVECited in: Differential Diagnosis - [71]
Farmakis IT, Valerio L, Barco S et al.. “Functional capacity and dyspnea during follow-up after acute pulmonary embolism.” Journal of thrombosis and haemostasis : JTH (2024). PMID: 37652350 ↗
L5OTHERCited in: Differential Diagnosis - [72]
Cerullo M, Yang K, Joynt Maddox KE et al.. “Association Between Hospital Private Equity Acquisition and Outcomes of Acute Medical Conditions Among Medicare Beneficiaries.” JAMA network open (2022). PMID: 35486398 ↗
L5OTHERCited in: Differential Diagnosis - [73]
Beltaief K, Msolli MA, Zorgati A et al.. “Nebulized Terbutaline and Ipratropium Bromide Versus Terbutaline Alone in Acute Exacerbation of Chronic Obstructive Pulmonary Disease Requiring Noninvasive Ventilation: A Randomized Double-blind Controlled Trial.” Academic emergency medicine : official journal of the Society for Academic Emergency Medicine (2019). PMID: 30156361 ↗
L1bRCTCited in: Management: Pharmacological Therapy - [74]
Ding Z, Li X, Lu Y et al.. “A randomized, controlled multicentric study of inhaled budesonide and intravenous methylprednisolone in the treatment on acute exacerbation of chronic obstructive pulmonary disease.” Respiratory medicine (2016). PMID: 27888990 ↗
L1bRCTCited in: Management: Pharmacological Therapy - [75]
Wang JX, Zhang SM, Li XH et al.. “Acute exacerbations of chronic obstructive pulmonary disease with low serum procalcitonin values do not benefit from antibiotic treatment: a prospective randomized controlled trial.” International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases (2016). PMID: 27155210 ↗
L1bRCTCited in: Management: Pharmacological Therapy - [76]
Gold DR, Litonjua AA, Carey VJ et al.. “Lung VITAL: Rationale, design, and baseline characteristics of an ancillary study evaluating the effects of vitamin D and/or marine omega-3 fatty acid supplements on acute exacerbations of chronic respiratory disease, asthma control, pneumonia and lung function in adults.” Contemporary clinical trials (2016). PMID: 26784651 ↗
L1bRCTCited in: Management: Pharmacological Therapy - [77]
Geiger-Brown J, Lindberg S, Krachman S et al.. “Self-reported sleep quality and acute exacerbations of chronic obstructive pulmonary disease.” International journal of chronic obstructive pulmonary disease (2015). PMID: 25759571 ↗
L1bRCTCited in: Management: Pharmacological Therapy - [78]
Rabe KF, Fabbri LM, Israel E et al.. “Effect of ADRB2 polymorphisms on the efficacy of salmeterol and tiotropium in preventing COPD exacerbations: a prespecified substudy of the POET-COPD trial.” The Lancet. Respiratory medicine (2014). PMID: 24461901 ↗
L1bRCTCited in: Management: Pharmacological Therapy - [79]
Rogliani P, Ora J, Ciaprini C et al.. “Effect of indacaterol on arterial blood gases in patients suffering from acute exacerbation of COPD.” Respiratory medicine (2014). PMID: 24238769 ↗
L1bRCTCited in: Management: Pharmacological Therapy - [80]
Anzueto A, Niewoehner DE, Leimer I et al.. “A post hoc pooled analysis of exacerbations among US participants in randomized controlled trials of tiotropium.” Respiratory medicine (2013). PMID: 23969305 ↗
L1bRCTCited in: Management: Pharmacological Therapy - [81]
Leuppi JD, Schuetz P, Bingisser R et al.. “Short-term vs conventional glucocorticoid therapy in acute exacerbations of chronic obstructive pulmonary disease: the REDUCE randomized clinical trial.” JAMA (2013). PMID: 23695200 ↗
L1bRCTCited in: Management: Pharmacological Therapy - [82]
Torres-Sánchez I, Valenza MC, Cabrera-Martos I et al.. “Effects of an Exercise Intervention in Frail Older Patients with Chronic Obstructive Pulmonary Disease Hospitalized due to an Exacerbation: A Randomized Controlled Trial.” COPD (2017). PMID: 27715322 ↗
L1bRCTCited in: Management: Pharmacological Therapy, Management: Respiratory Support - [83]
Rohde GG, Koch A, Welte T. “Randomized double blind placebo-controlled study to demonstrate that antibiotics are not needed in moderate acute exacerbations of COPD--the ABACOPD study.” BMC pulmonary medicine (2015). PMID: 25623589 ↗
L1bRCTCited in: Management: Pharmacological Therapy, Management: Respiratory Support - [84]
Segreti A, Fiori E, Calzetta L et al.. “The effect of indacaterol during an acute exacerbation of COPD.” Pulmonary pharmacology & therapeutics (2013). PMID: 23578980 ↗
L1bRCTCited in: Management: Pharmacological Therapy - [85]
Postma DS, Anzueto AR, Jenkins C et al.. “Factor analysis in predominantly severe COPD: identification of disease heterogeneity by easily measurable characteristics.” Respiratory medicine (2013). PMID: 23953956 ↗
L2aSR_OBSCited in: Management: Pharmacological Therapy - [86]
Vermeersch K, Gabrovska M, Deslypere G et al.. “The Belgian trial with azithromycin for acute COPD exacerbations requiring hospitalization: an investigator-initiated study protocol for a multicenter, randomized, double-blind, placebo-controlled trial.” International journal of chronic obstructive pulmonary disease (2016). PMID: 27099485 ↗
L5OTHERCited in: Management: Pharmacological Therapy - [87]
Lopardo G, Pensotti C, Scapellato P et al.. “[Inter-society consensus for the management of respiratory infections: acute bronchitis and chronic obstructive pulmonary disease].” Medicina (2013). PMID: 23570768 ↗
L1cGUIDELINECited in: Management: Pharmacological Therapy, Guidelines and Resources - [88]
Yang L, Li M, Shu J et al.. “A Risk Prediction Model for Prolonged Length of Stay in Patients with Acute Exacerbations of Chronic Obstructive Pulmonary Disease: A Retrospective Study of 225 Patients in a Single Center in Kunming, China.” Medical science monitor : international medical journal of experimental and clinical research (2022). PMID: 35136009 ↗
L2bCOHORTCited in: Management: Pharmacological Therapy - [89]
Walters JA, Tan DJ, White CJ et al.. “Systemic corticosteroids for acute exacerbations of chronic obstructive pulmonary disease.” The Cochrane database of systematic reviews (2014). PMID: 25178099 ↗
L2aSR_OBSCited in: Management: Pharmacological Therapy - [90]
Whittaker Brown SA, Braman S. “Recent Advances in the Management of Acute Exacerbations of Chronic Obstructive Pulmonary Disease.” The Medical clinics of North America (2020). PMID: 32505256 ↗
L5REVIEW_NARRATIVECited in: Management: Pharmacological Therapy, Management: Respiratory Support - [91]
Komagamine J. “Prevalence of potentially inappropriate medications at admission and discharge among hospitalised elderly patients with acute medical illness at a single centre in Japan: a retrospective cross-sectional study.” BMJ open (2018). PMID: 30030316 ↗
L5OTHERCited in: Management: Pharmacological Therapy - [92]
Naderi N, Assayag D, Mostafavi-Pour-Manshadi SM et al.. “Long-term azithromycin therapy to reduce acute exacerbations in patients with severe chronic obstructive pulmonary disease.” Respiratory medicine (2018). PMID: 29724384 ↗
L5OTHERCited in: Management: Pharmacological Therapy - [93]
Su VY, Yang KY, Yang YH et al.. “Use of ICS/LABA Combinations or LAMA Is Associated with a Lower Risk of Acute Exacerbation in Patients with Coexistent COPD and Asthma.” The journal of allergy and clinical immunology. In practice (2018). PMID: 29432960 ↗
L5OTHERCited in: Management: Pharmacological Therapy - [94]
Kelly AM, Holdgate A, Keijzers G et al.. “Epidemiology, treatment, disposition and outcome of patients with acute exacerbation of COPD presenting to emergency departments in Australia and South East Asia: An AANZDEM study.” Respirology (Carlton, Vic.) (2018). PMID: 29394524 ↗
L5OTHERCited in: Management: Pharmacological Therapy, Management: Respiratory Support - [95]
Ergan B, Ergün R. “Impact of anemia on short-term survival in severe COPD exacerbations: a cohort study.” International journal of chronic obstructive pulmonary disease (2016). PMID: 27536089 ↗
L2bCOHORTCited in: Management: Respiratory Support - [96]
Corrêa TD, Sanches PR, de Morais LC et al.. “Performance of noninvasive ventilation in acute respiratory failure in critically ill patients: a prospective, observational, cohort study.” BMC pulmonary medicine (2015). PMID: 26559350 ↗
L2bCOHORTCited in: Management: Respiratory Support - [97]
Jayadev A, Stone R, Steiner MC et al.. “Time to NIV and mortality in AECOPD hospital admissions: an observational study into real world insights from National COPD Audits.” BMJ open respiratory research (2019). PMID: 31423314 ↗
L5OTHERCited in: Management: Respiratory Support - [98]
Comellini V, Pacilli AMG, Nava S. “Benefits of non-invasive ventilation in acute hypercapnic respiratory failure.” Respirology (Carlton, Vic.) (2019). PMID: 30636373 ↗
L5REVIEW_NARRATIVECited in: Management: Respiratory Support - [99]
Miró Ò, Martínez G, Masip J et al.. “Effects on short term outcome of non-invasive ventilation use in the emergency department to treat patients with acute heart failure: A propensity score-based analysis of the EAHFE Registry.” European journal of internal medicine (2018). PMID: 29572091 ↗
L5OTHERCited in: Management: Respiratory Support - [100]
Parker K, Perikala V, Aminazad A et al.. “Models of care for non-invasive ventilation in the Acute COPD Comparison of three Tertiary hospitals (ACT3) study.” Respirology (Carlton, Vic.) (2018). PMID: 29224257 ↗
L5OTHERCited in: Management: Respiratory Support - [101]
Poon T, Paris DG, Aitken SL et al.. “Extended Versus Short-Course Corticosteroid Taper Regimens in the Management of Chronic Obstructive Pulmonary Disease Exacerbations in Critically Ill Patients.” Journal of intensive care medicine (2020). PMID: 29161935 ↗
L5OTHERCited in: Management: Respiratory Support - [102]
Lemyze M, Bury Q, Guiot A et al.. “Delayed but successful response to noninvasive ventilation in COPD patients with acute hypercapnic respiratory failure.” International journal of chronic obstructive pulmonary disease (2017). PMID: 28579772 ↗
L5OTHERCited in: Management: Respiratory Support - [103]
Song Y, Chen R, Zhan Q et al.. “The optimum timing to wean invasive ventilation for patients with AECOPD or COPD with pulmonary infection.” International journal of chronic obstructive pulmonary disease (2016). PMID: 27042042 ↗
L5REVIEW_NARRATIVECited in: Management: Respiratory Support - [104]
Pisani L, Corcione N, Nava S. “Management of acute hypercapnic respiratory failure.” Current opinion in critical care (2016). PMID: 26627537 ↗
L5REVIEW_NARRATIVECited in: Management: Respiratory Support - [105]
Fan L, Zhao Q, Liu Y et al.. “Semiquantitative cough strength score and associated outcomes in noninvasive positive pressure ventilation patients with acute exacerbation of chronic obstructive pulmonary disease.” Respiratory medicine (2014). PMID: 25459451 ↗
L5OTHERCited in: Management: Respiratory Support - [106]
Brill SE, Wedzicha JA. “Oxygen therapy in acute exacerbations of chronic obstructive pulmonary disease.” International journal of chronic obstructive pulmonary disease (2014). PMID: 25404854 ↗
L5REVIEW_NARRATIVECited in: Management: Respiratory Support - [107]
Ongel EA, Karakurt Z, Salturk C et al.. “How do COPD comorbidities affect ICU outcomes?” International journal of chronic obstructive pulmonary disease (2014). PMID: 25378919 ↗
L5OTHERCited in: Management: Respiratory Support - [108]
Lindenauer PK, Stefan MS, Shieh MS et al.. “Outcomes associated with invasive and noninvasive ventilation among patients hospitalized with exacerbations of chronic obstructive pulmonary disease.” JAMA internal medicine (2014). PMID: 25347545 ↗
L5OTHERCited in: Management: Respiratory Support - [109]
Park MJ, Rhee CK, Kim YH et al.. “Efficacy and safety of HL301 in the treatment of acute bronchitis and acute exacerbation of chronic bronchitis: a phase 2, randomized, double-blind, placebo-controlled, multicenter study.” Current medical research and opinion (2017). PMID: 28277874 ↗
L1bRCTCited in: Prognosis and Long-term Outcomes - [110]
Mir T, Uddin M, Khalil A et al.. “Mortality outcomes associated with invasive aspergillosis among acute exacerbation of chronic obstructive pulmonary disease patient population.” Respiratory medicine (2022). PMID: 34959147 ↗
L5OTHERCited in: Prognosis and Long-term Outcomes - [111]
Hoffman GJ, Yakusheva O. “Association Between Financial Incentives in Medicare's Hospital Readmissions Reduction Program and Hospital Readmission Performance.” JAMA network open (2020). PMID: 32242906 ↗
L5OTHERCited in: Prognosis and Long-term Outcomes - [112]
Spannella F, Giulietti F, Cocci G et al.. “Acute Exacerbation of Chronic Obstructive Pulmonary Disease in Oldest Adults: Predictors of In-Hospital Mortality and Need for Post-acute Care.” Journal of the American Medical Directors Association (2019). PMID: 30826270 ↗
L5OTHERCited in: Prognosis and Long-term Outcomes - [113]
Chen W, Qing-yuan Z. “[Guideline for mechanical ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease (2007)].” Zhongguo wei zhong bing ji jiu yi xue = Chinese critical care medicine = Zhongguo weizhongbing jijiuyixue (2007). PMID: 17767816 ↗
L1cGUIDELINECited in: Guidelines and Resources - [114]
Singer D, Wang Y, La EM et al.. “Long-term Clinical Outcomes After Hospitalization for Acute Respiratory Illness Due to Respiratory Syncytial Virus.” Clinical infectious diseases : an official publication of the Infectious Diseases Society of America (2026). PMID: 41432364 ↗
L3bCited in: Etiology and Triggering Factors - [115]
Nirappil FJ, Maheshwari A, Andrews J et al.. “Characteristics and outcomes of HIV-1-infected patients with acute respiratory distress syndrome.” Journal of critical care (2014). PMID: 25466320 ↗
L3bCited in: Etiology and Triggering Factors - [116]
Hui DS, Ip M, Ling T et al.. “A multicentre surveillance study on the characteristics, bacterial aetiologies and in vitro antibiotic susceptibilities in patients with acute exacerbations of chronic bronchitis.” Respirology (Carlton, Vic.) (2011). PMID: 21299688 ↗
L3bCited in: Etiology and Triggering Factors - [117]
Nseir S, Cavestri B, Di Pompeo C et al.. “Factors predicting bacterial involvement in severe acute exacerbations of chronic obstructive pulmonary disease.” Respiration; international review of thoracic diseases (2008). PMID: 18547944 ↗
L2bCited in: Etiology and Triggering Factors - [118]
Homma T, Kawahara T, Mikuni H et al.. “Beneficial Effect of Early Intervention with Garenoxacin for Bacterial Infection-Induced Acute Exacerbation of Bronchial Asthma and Chronic Obstructive Pulmonary Disease.” International archives of allergy and immunology (2019). PMID: 30759444 ↗
L2bCited in: Etiology and Triggering Factors - [119]
Ohteru Y, Kakugawa T, Kakugawa M et al.. “Impact of the COVID-19 pandemic on acute exacerbation of idiopathic pulmonary fibrosis: a nationwide observational study in Japan.” Respiratory investigation (2025). PMID: 41253080 ↗
L3bCited in: Etiology and Triggering Factors - [120]
Boixeda R, Bacca S, Elias L et al.. “Pneumonia as comorbidity in chronic obstructive pulmonary disease (COPD). Differences between acute exacerbation of COPD and pneumonia in patients with COPD.” Archivos de bronconeumologia (2014). PMID: 25443591 ↗
L2bCited in: Etiology and Triggering Factors - [121]
Piñol-Ripoll G, de la Puerta I, Santos S et al.. “Chronic bronchitis and acute infections as new risk factors for ischemic stroke and the lack of protection offered by the influenza vaccination.” Cerebrovascular diseases (Basel, Switzerland) (2008). PMID: 18728360 ↗
L3bCited in: Etiology and Triggering Factors - [122]
Lapanan C, Schreiber AF, Wongtirawit N et al.. “The effects of asymmetrical versus symmetrical high-flow nasal cannula on respiratory muscle activity in acute hypoxaemic respiratory failure and chronic obstructive pulmonary disease: A randomised crossover study.” Pulmonology (2026). PMID: 42345563 ↗
L1bCited in: Diagnosis and Workup - [123]
Brendel JH, Andersen LW, Skaarup SH et al.. “Prehospital Use of Non-Invasive Ventilation for Acute Respiratory Failure due to Acute Exacerbation of Chronic Obstructive Pulmonary Disease. A Randomised Trial.” Acta anaesthesiologica Scandinavica (2026). PMID: 42219224 ↗
L1bCited in: Diagnosis and Workup - [124]
Fisher KA, Stefan MS, Darling C et al.. “Impact of COPD on the mortality and treatment of patients hospitalized with acute decompensated heart failure: the Worcester Heart Failure Study.” Chest (2015). PMID: 25188234 ↗
L3bCited in: Differential Diagnosis - [125]
Parissis JT, Andreoli C, Kadoglou N et al.. “Differences in clinical characteristics, management and short-term outcome between acute heart failure patients chronic obstructive pulmonary disease and those without this co-morbidity.” Clinical research in cardiology : official journal of the German Cardiac Society (2014). PMID: 24718849 ↗
L4Cited in: Differential Diagnosis - [126]
Stefan MS, Rothberg MB, Priya A et al.. “Association between β-blocker therapy and outcomes in patients hospitalised with acute exacerbations of chronic obstructive lung disease with underlying ischaemic heart disease, heart failure or hypertension.” Thorax (2012). PMID: 22941975 ↗
L3bCited in: Differential Diagnosis - [127]
Ovchinnikova ES, Schmitter D, Vegter EL et al.. “Signature of circulating microRNAs in patients with acute heart failure.” European journal of heart failure (2015). PMID: 26345695 ↗
L3bCited in: Differential Diagnosis - [128]
Pizzini A, Lunger F, Sahanic A et al.. “Diagnostic and Prognostic Value of Inflammatory Parameters Including Neopterin in the Setting of Pneumonia, COPD, and Acute Exacerbations.” COPD (2017). PMID: 28548632 ↗
L3bCited in: Differential Diagnosis - [129]
Bahloul M, Chaari A, Tounsi A et al.. “Incidence and impact outcome of pulmonary embolism in critically ill patients with severe exacerbation of chronic obstructive pulmonary diseases.” The clinical respiratory journal (2014). PMID: 24612880 ↗
L3bCited in: Differential Diagnosis - [130]
Hanania NA, Calverley PM, Dransfield MT et al.. “Pooled subpopulation analyses of the effects of roflumilast on exacerbations and lung function in COPD.” Respiratory medicine (2013). PMID: 24120253 ↗
L1bCited in: Management: Pharmacological Therapy - [131]
Ozsancak Ugurlu A, Habesoglu MA. “Epidemiology of NIV for Acute Respiratory Failure in COPD Patients: Results from the International Surveys vs. the "Real World".” COPD (2017). PMID: 28636452 ↗
L1bCited in: Management: Respiratory Support - [132]
Fiorino S, Bacchi-Reggiani L, Detotto E et al.. “Efficacy of non-invasive mechanical ventilation in the general ward in patients with chronic obstructive pulmonary disease admitted for hypercapnic acute respiratory failure and pH < 7.35: a feasibility pilot study.” Internal medicine journal (2015). PMID: 25684643 ↗
L4Cited in: Management: Respiratory Support - [133]
Loh CH, Peters SP, Lovings TM et al.. “Suboptimal Inspiratory Flow Rates Are Associated with Chronic Obstructive Pulmonary Disease and All-Cause Readmissions.” Annals of the American Thoracic Society (2017). PMID: 28406710 ↗
L3bCited in: Prognosis and Long-term Outcomes