Acute Exacerbations of COPD

Exacerbations of chronic obstructive pulmonary disease (COPD) are defined as a sustained worsening of the patient's symptoms from his or her usual stable state that is beyond normal day-to-day variations, and is acute in onset. Commonly reported symptoms are worsening breathlessness, cough, increased sputum production and change in sputum colour.¹

• Most community-acquired infections are due to Streptococcus pneumoniae and Haemophilus influenzae, and less commonly Moraxella catarrhalis.
• Staphylococcus aureus may be the cause during the influenza season. Infection with Pseudomonas aeruginosa may also cause exacerbations of COPD.
• Known viral causes of exacerbations of COPD include rhinoviruses, influenza, parainfluenza, coronavirus, adenovirus and respiratory syncytial virus.
• Common pollutants such as nitrogen dioxide, particulates, sulphur dioxide and ozone may also trigger exacerbations.

Exacerbations of COPD can be associated with the following symptoms:¹

• Increased dyspnoea
• Increased cough; increased sputum purulence and increased sputum volume
• Upper airway symptoms (e.g. colds and sore throats)
• Increased wheeze and chest tightness
• Reduced exercise tolerance
• Fluid retention
• Increased fatigue
• Marked respiratory distress with dyspnoea and tachypnoea, acute confusion, increased cyanosis, peripheral oedema

Other causes of similar symptoms in patients with COPD are:¹

• Pneumonia
• Pneumothorax
• Left ventricular failure/pulmonary oedema
• Pulmonary embolus
• Lung cancer
• Upper airway obstruction
• Pleural effusion
• Recurrent aspiration

The following signs are features of a severe exacerbation:¹

• Marked dyspnoea
• Tachypnoea
• Purse lip breathing
• Use of accessory muscles (sternomastoid and abdominal) at rest
• Acute confusion
• New onset cyanosis
• New onset peripheral oedema
• Marked reduction in activities of daily living

In patients with an exacerbation managed in primary care

• Sending sputum samples for culture is not recommended in routine practice because empirical therapy is effective and should be prescribed promptly if the sputum is purulent.
• Pulse oximetry is of value if there are clinical features of a severe exacerbation.

In all patients with an exacerbation referred to hospital

• A chest x-ray should be obtained.
• Arterial blood gas tensions should be measured and the inspired oxygen concentration must be recorded.
• An ECG to exclude comorbidities.
• Full blood count, renal function and electrolyte concentrations.
• A theophylline level should be measured in patients on theophylline therapy at admission.
• If sputum is purulent, a sample should be sent for microscopy and culture.
• Blood cultures should be taken if the patient is pyrexial.

Most patients with an exacerbation of COPD can be managed at home but a few need hospital treatment. Recent trials have shown that about 30% of patients referred for hospital admission could be successfully treated at home with immediate or early supported discharge and nurse led home care.¹ The decision whether to refer to hospital involves:

• An assessment of the severity of symptoms (degree of breathlessness, presence of cyanosis or peripheral oedema and the level of consciousness).
• The presence of co-morbidities.
• Whether or not the patient is already receiving long term oxygen therapy.
• The level of physical functioning.
• The patient's ability to cope at home.
• Patients should be admitted if:¹
  • Their condition worsens.
  • Symptoms are not being adequately controlled.
  • Oxygen saturation levels are falling.
  • The patient's social circumstances warrant admission.

Drugs

According to the NICE guidelines the principles of treatment are:¹

• High-dose short acting bronchodilators (inhalers used with a spacer device are as effective as nebulisers). There is no evidence that the degree of bronchodilation achieved with ipratropium bromide is greater than that using a short-acting beta₂-agonist for patients with acute exacerbations of COPD.²
• Oral steroids:
  • Prednisolone 30 mg daily for seven to 14 days (for all patients with a significant increase in breathlessness unless contraindicated).
  • There is no advantage in more prolonged corticosteroid therapy.
  • Osteoporosis prophylaxis should be considered in patients requiring frequent courses of oral corticosteroids.
• Antibiotics:
  • Only if the sputum is purulent or there are signs of consolidation. Initial empirical treatment should be amoxicillin, erythromycin or a tetracycline. Some pneumococci and Haemophilus influenzae strains are tetracycline-resistant and approximately 15% of H. influenzae strains are amoxicillin-resistant.
  • Always take account of any guidance issued by local microbiologists.
  • When sputum has been sent for culture, the appropriateness of antibiotic treatment should be checked against laboratory culture and sensitivities when they become available.¹
• Oxygen should be given to maintain SaO₂ above 90%. NICE guidelines state that oxygen should be prescribed for patients who are breathless during an exacerbation even in the absence of oximetry or blood gases.¹
• Intravenous theophylline has only a minor role in management and its use is appropriate in a minority of patients. It should only be used as an adjunct to the management if there is an inadequate response to high dose bronchodilators and oral steroids. Blood theophylline levels should be carefully monitored and great care is required to avoid toxicity, especially for potential interactions with other drugs if the patient has been on oral theophylline.
• Respiratory stimulants: doxapram should only be used when non-invasive ventilation is either unavailable or considered inappropriate.¹
• Non-invasive positive pressure ventilation (NPPV) should be used as the treatment of choice for persistent hypercapnic ventilatory failure during exacerbations despite optimal medical therapy. NPPV reduces the risk of intubation and in-hospital mortality.³
• Invasive ventilation and intensive care: age, FEV₁, functional status, BMI, requirement for oxygen when stable, co-morbidities and previous admissions to intensive care units should be considered when assessing suitability for intubation and ventilation. Neither age nor FEV₁ should be used in isolation when assessing suitability.
• Physiotherapy using positive expiratory pressure masks should be considered for selected patients, to help with clearing sputum.

• Spirometry should be measured in all patients before discharge.
• Advanced discharge planning helps to reduce the risk of readmission. Discharge planning involves an assessment of the patients fitness for discharge and assessment of their needs once back in the community.
• Patients (and their carers) should be given appropriate information to enable them to fully understand the correct use of medications, including oxygen, before discharge. Arrangements for follow-up and home care (e.g. visiting nurse, oxygen delivery, referral for other support) should be made before discharge.
• Pulmonary rehabilitation should be arranged as appropriate.

• Studies of a cohort of patients observed in the community have shown that symptoms and peak expiratory flow rates recover slowly after an exacerbation.
• The median for recovery of symptoms was 7 days.
• Recovery of PEFR to baseline was complete in 75% of patients at 35 days and 93% at 91 days.¹
• A retrospective audit of 1400 admissions to hospital in the UK with an exacerbation of COPD has shown that 34% were re-admitted and 14% had died within 3 months.¹
• Patients experiencing frequent exacerbations have more rapid lung function decline.¹

• Appropriate influenza immunisation and pneumococcal immunisation.
• Optimal control of stable COPD and relevant co-morbidities (e.g. diabetes mellitus, ischaemic heart disease).
• Patients should have a self-management plan, which should include appropriate action at the first sign of an acute exacerbation.