In this post are excerpts from Chapter 5: Management of Exacerbations of the GOLD 2017 guidelines:
Summary
- Exacerbation of COPD is defined as an acute worsening of respiratory symptoms that result in additional therapy.
- Exacerbations of COPD can be precipitated by several factors. The most common causes are respiratory tract infections.
- The goal of treatment of COPD exacerbations is to minimize the negative impact of the current exacerbation and to prevent subsequent events.
- Short acting inhaled beta agonists, with or without short acting anticholinergics, are recommended as the initial bronchodilators to treat an acute exacerbation.
- Maintenance therapy with long acting bronchodilator should be initiated as soon as possible before hospital discharge.
- Systemic corticosteroids can improve lung function (FEV1), oxygenation and short recovery time and hospitalization duration. Duration of therapy should be 5 to 7 days.
- Antibiotics, when indicated, can shorten recovey time, reduce the risk of early relapse, treatment failure, and hospitalization duration. Duration of therapy should be 5 – 7 days.
- Methylxanthines are not recommended due to increased side effect profiles.
- Noninvasive mechanical ventilation should be the first load of ventilation used in COPD patients with acute respiratory failure who have no absolute contraindications because it improves gas exchange, reduces the work of breathing and the need for innovation, decreases hospitalization duration and improve survival.
- Following exacerbation, appropriate measures for exacerbation prevention should be initiated [see chapters 3 and four of the 2017 guidelines].
COPD exacerbations are defined as an acute worsening of respiratory symptoms that result in additional therapy.
They are classified as:
- Mild (treated with short acting bronchodilator only, SABDs)
- Moderate (treated with SABDs plus antibiotics and/or oral corticosteroids) or
- Severe (patient requires hospitalization or visits the emergency room). Severe exacerbations may also be associated with acute respiratory failure.
Exacerbations are mainly triggered by respiratory viral infections although bacterial infections and environmental factors such as pollution and ambient temperature may also initiate and/or amplify these events. The most common virus isolated is human rhinovirus (the cause of the common cold) and can be detected for up to a week after exacerbation when associated with viral infections, exacerbations are often more severe, last longer, and precipitate more hospitalization, as seen during the winter.
During a COPD exacerbation symptoms usually last between 7 to 10 days, but some events may last longer. At eight weeks, 20% of patients have not recovered to their pre-exacerbation state. It is well-established that COPD exacerbations contribute to disease progression. Disease progression is even more likely if recovery from exacerbations is slow. Exacerbations can also cluster in time and once a COPD patient experiences an exacerbation, they will show increased susceptibility to another event.
Some COPD patients are particularly susceptible to frequent exacerbations (defined as to or more exacerbations per year, and these patients have been shown to have worse health status and morbidity then patients with less frequent exacerbations. Patients at high risk of frequent exacerbations can be recognized across all disease severity groups and the strongest predictor of the patient’s future exacerbation frequency is the number of exacerbations they have had in the prior year.
Treatment Setting
The clinical presentation of COPD exacerbation is heterogenous, thus we recommend that in hospitalized patients the severity of the exacerbation should be based on patient’s clinical signs and recommend the following classification.
No respiratory failure: respiratory rate: 20 to 30 breast; no use accessory respiratory muscles; no change in mental status; hypoxia improved with supplemental oxygen given via Venturi mask 28 to 35% inspired oxygen (FI 02); no increase in PaCO2.
Acute respiratory failure – non-life-threatening: respiratory rate greater than 30 breast per minute; using accessory respiratory muscles; no change in mental status; hypoxemia improved with supplemental oxygen via Venturi mask 35 to 40% FI02; hypercarbia, PaCO2 increased compared with baseline or elevated 50 to 60 mmHg.
Acute respiratory failure – life-threatening: respiratory rate greater than 30 breast per minute; using accessory respiratory muscles; acute changes in mental status; hypoxemia not improve with supplemental oxygen via Venturi mask or requiring FIO2 greater than 40%; hypercapnia i.e., PaCO2 increased compared with the baseline or elevated greater than 60 mmHg for the presence of acidosis (pH less than or equal to 7.25).
Potential indications for hospital assessment
- Severe symptoms such as sudden worsening of resting dyspnea, high respiratory rate, decreased oxygen saturation, confusion, drowsiness.
- Acute respiratory failure.
- Onset of new physical signs (e.g., cyanosis, peripheral edema).
- Failure of exacerbation to respond to initial medical management.
- Presence of serious comorbidities (e.g., heart failure, newly occurring arrhythmias, etc.).
- Insufficient home support.
Management of severe but not life-threatening exacerbations
- Assess severity of symptoms, blood gases, chest radiographs.
- Administer supplemental oxygen therapy, obtain serial arterial blood gases, venous blood gas and pulse oximetry measurements.
- Bronchodilators:
- Increased doses and/or frequency of short acting bronchodilators.
- Combine short acting beta two agonists and anticholinergics.
- Consider use of long-acting bronchodilators when the patient becomes stable.
- Use spacers are air-driven nebulizers when appropriate.
- Consider oral corticosteroids.
- Consider antibiotics (oral) when signs of bacterial infection are present.
- Consider noninvasive mechanical ventilation (NIV).
- At all times:
- Monitor fluid balance.
- Consider subcutaneous heparin or low molecular weight heparin for thromboembolism prophylaxis.
- Identify and treat associated conditions (e.g., heart failure, arrhythmias, pulmonary embolism etc.).
Long-term prognosis following hospitalization for COPD is for, with a five-year mortality rate of about 50%.
Summary for the management of exacerbations:
- Short acting beta two agonists, with or without short acting anticholinergics are recommended as the initial bronchodilators to treat an acute exacerbation.
- Systemic corticosteroids can improve lung function (FEV1), oxygenation and short recovery time and hospitalization duration. Duration of therapy should be no more than 5 to 7 days.
- Antibiotics, when indicated, can short recovery time reduce the risk of early relapse, treatment, and hospitalization duration. Duration of therapy should be 5 -7 days.
- Methylxanthines are not recommended due to increased side effect profiles.
- Non-invasive mechanical ventilation should be the first mode of ventilation used in COPD patients with acute respiratory failure.
NIV should be the first mode of ventilation used in COPD patients with acute respiratory failure who have no absolute contraindications because it improves gas exchange, reduces work of breathing, and the need for intubation, decreases hospitalization duration and improve survival.
Pharmacologic Treatment
The three classes of medications most commonly used for COPD exacerbations are bronchodilators, steroids, and antibiotics.
Bronchodilators:
- It is recommended that short acting inhaled beta agonists, with or without short acting anticholinergics, are the initial bronchodilators for acute treatment of COPD exacerbation.
Glucocorticoids:
Data from studies indicate systemic glucocorticoids in COPD exacerbations short recovery time and improve lung function (FEV1). They also improve oxygenation, the risk of early relapse, treatment failure, and the length of hospitalization. A dose of 40 mg prednisone per day for five days is recommended. Therapy with oral prednisone is equally effective to intravenous administration.
Antibiotics:
A systematic review of placebo-controlled studies has shown in a biotics reduce the risk of short-term mortality by 77% treatment failure by 53% and you imperialist by 44%. The review provides evidence to treat moderately or severely ill patients with COPD exacerbations and increased cough and sputum with antibiotics. These data are supported by more recent RCTs in patients with diagnoses of moderate COPD.
In summary, antibiotics should be given to patients with exacerbation of COPD who have three cardinal symptoms: increasing dyspnea, sputum volume, and sputum purulence; have two of the cardinal symptoms if increased purulence of sputum is one of the two symptoms; or require mechanical ventilation (invasive or noninvasive). The recommended of antibiotic therapy is 5 to 7 days.
Usually initial empirical treatment is an aminopenicillin with clavulanic acid, macrolide, or tetracycline.
The route of administration (oral or intravenous) depends on the patient’s ability and the pharmacokinetics of the antibiotic, although it is preferable that antibiotics be given orally. Improvements in dyspnea and sputum purulence suggests clinical success.
Respiratory Support
Oxygen Therapy:
This is a key component of hospital treatment of exacerbation. Supplemental oxygen should be titrated to improve the patient’s hypoxemia with the target saturation of 88 to 92%. Once oxygen is started, blood gases should be checked frequently to ensure satisfactory oxygenation without carbon dioxide retention and/or worsening acidosis. A recent study demonstrated that venous blood gas to assess bicarbonate levels and pH is accurate when compared with arterial blood gas assessment. [GOLD 2017 states that additional data are needed to support that study]
Indications for respiratory or medical intensive care unit admission:
- Severe dyspnea that responds inadequately to initial emergency therapy.
- Changes in mental status (confusion, lethargy,coma).
- Persistent or worsening hypoxemia (PaO2 of less than 40 mmHg and/or severe/worsening respiratory acidosis (pH less than 7.25) despite supplemental oxygen and the noninvasive relation.
- Need for invasive mechanical ventilation.
- Hemodynamic instability – – need for vasopressors.
Noninvasive Mechanical Ventilation:
The use of noninvasive mechanical ventilation (NIV) is preferred over invasive ventilation (intubation and positive pressure ventilation) and the initial mode ventilation the treatment acute respiratory failure in patients hospitalized for acute exacerbations of COPD. . . . NIV has been shown to improve oxygenation and acute respiratory acidosis ID, NIV increases pH and decreases the PaCO2. NIV also increases respiratory rate, work of breathing and severity of breathlessness but also decreases complications such as ventilator associated pneumonia, and length of stay. Most importantly, mortality and innovation rates are reduced by this intervention.
Indications for noninvasive mechanical ventilation (NIV)
At least one of the following:
- Respiratory acidosis (PaCO2 of greater than or equal to 45 mmHg and arterial pH of less than or equal to 7.35).
- Severe dyspnea with clinical signs suggestive of respiratory muscle fatigue, increased work of breathing, or both, such as use of respiratory accessory muscles, paradoxical motion of the abdomen, or retraction of the intercostal space.
- Persistent hypoxemia despite supplemental oxygen therapy.
Indications for invasive mechanical ventilation
- Unable to tolerate NIV or NIV failure.
- Status post respiratory or cardiac arrest.
- Diminished consciousness, psychomotor agitation inadequately controlled by sedation.
- Passive aspiration or persistent vomiting.
- Persistent inability to remove respiratory secretions.
- Severe hemodynamic instability without response to fluids and vasoactive drugs.
- Severe ventricular or supraventricular arrhythmias.
- Life-threatening hypoxemia in patients unable to tolerate NIV.
When patients meet discharge criteria, it is important that appropriate follow up is arranged and that all the interventions that reduce the frequency of COPD exacerbations have been initiated.
Resources
(1) The Global Initiative For Chronic Obstructive Lung Disease has published GOLD 2017 Global Strategy for the Diagnosis, Management and Prevention of COPD[Download link to PDF] and the POCKET GUIDE TO COPD DIAGNOSIS, MANAGEMENT, AND PREVENTION: A Guide for Health Care Professionals 2017 REPORT [Link is to the PDF]
