COPD exacerbation

Objectives


1. Clinical diagnosis of COPD exacerbation
2. Principles of initial management
3. Assessing the clinical response
4. Principles of managing refractory exacerbation


1. Clinical diagnosis of COPD exacerbation

• Patients usually present with increasing SOB.
• If the precipitant is an infection, they may also have productive cough with yellowish sputum, fever, anorexia, pleuritic chest pain
• In patients with advanced COPD there will be
• Features of hyperinflation - Barrel shape, impaired cardiac and liver dullness
• Features of Cor-pulmonale - Elevated JVP, Edema, Tender hepatomegaly
• Generalized wasting
• Look for features of hypoxia - Cyanosis
• Look for features of CO2 retention - Flapping tremors, Bounding pulses

2. Principles of initial management

• These patients need HDU care.
• Patient should be propped up and attached to a monitor.

• Oxygen therapy
• Should be administered cautiously.
• In patients with long standing COPD, especially if they have features of CO2 retention (see above), respiration is driven by hypoxic drive. (Read if you don't understand this concept).
• Therefore target saturation you should attempt to achieve is 88-92% and not more.
• Giving oxygen via venturi devices (28%, 32%) is recommended.
• This also is a common MCQ theme. A patients who's given high flow oxygen gets a saturation of 98% initially and 15 minutes later the patient found unconscious and desaturated.

• Bronchodilators
• Nebulization with beta agonists (salbutamol) and muscaranic antagonists (Ipratropium).

• Steroids
• IV hydrocortisone and Oral prednisolone are equally effective.

• Antibiotics
• Any exacerbation which requires hospitalization are usually treated with an antibiotic.

3. Assessing the clinical response

• If patient is clinically improving, same management can be continued.
• If the response is poor, ABG is the most informative investigation
• Typically long standing COPD patients have
• Acidosis
• Which is respiratory (CO2 high)
• With metabolic compensation (HCO3 also high)
• Bed side CXR may be helpful to detect complications like collapse/consolidation and pneumothorax.

4. Principles of managing refractory exacerbation

• Medications like aminophylline and MgSO4 are not very effective. 
• Best treatment modality is non-invasive ventilation(NIV).
• It is where you deliver oxygen in a high inspiratory and expiratory pressures to maintain the patency of airways.
• To deliver NIV patient should be conscious and cooperative. Usually it's given via a tight fitting mask and in instances where there are facial deformities or the patient is claustrophobic NIV can not be used.
• With NIV if the patient is not improving, or if the patient has contraindications for NIV, intubation and mechanical ventilation is the choice.