COPD & Respiratory Failure Flashcards
What is COPD?
How can exacerbations be reduced?
- Fixed airway obstruction, with little-to-no response to inhaled steroids.
- Characterised by persistent respiratory symptoms and airflow limitation due to airway and / or alveolar abnormalities, usually caused by significant exposure to noxious particles or gases.
- Exacerbations ar reduced with steroids.
- Management is based on symptoms control.
- FEV declines, inexrably.
What are the types of inhaler therapy used in COPD?
Broadly speaking, what is their mechanism of action?
- There are 3 kinds
- LABA - Salmeterol, Fomoterol
- LAMA - Triotropium
- ICS - Beclomethasone, Fluticasone, Budesonide
- Bronchodilators relax smooth muscle, improve airflow and improve breathlessness.
- Inhaled steroids reduce inflammation, and so exacerbation.
Describe the stepwise pharmacological management of COPD.
- LABA or LAMA
- ICS
- LABA or LAMA (whatever wasn’t used in first step)
- Usually:
- Prednisolone
- Aminophylline
- Oygen
- Nebulisers
What are the stimulatory and inhibitory factors in the development of pathology associated with COPD?
- There must be a host factor which modifies the initial noxious stimulus.
- Not everyone who smokes gets lung inflammation and people who don’t smoke get lung inflammation.
Describe the pathophysiology of COPD.
- Alveolar walls become obliterated.
- The larger alveolar sacs are not good for gas exchange.
- They also cause hyperinflation of the lungs and for this reason the chest is hyper-resonant upon percussion.
What are the treatment goals in COPD?
-
Reduce the symptoms
- Improve symptoms, exercise tolerance and health status.
-
Reduce the risk
- Disease progression, exacerbation and mortality.
Dscribe the prognosis of a COPD patient.
- Disease progression
- Rate of decline according to FEV%
What are the clinical features of COPD?
- Chronic cough +/- phlegm
- Chronic SOB
- Colds ‘go to the chest’
Describe the use of pulmonary function tests in COPD.
-
Spirometry
- Obstructive = FEV/FVC <0.70
- Predicted FEV:
- <30% = very severe
- 30-50% = severe
- 50-80% = moderate
- >80% = mild
-
Lung volumes
- Gas trapping causes increased residual volume, increased total lung capacity; RV/TLC.
-
Gas transfer
- Decreased TLCO
- Decreased VA
- Decreased KCO
-
Oxygen saturation and desaturation
- Prescribe O2 to maintain between 88-92%
Describe the use of imaging in the diagnosis of COPD.
- CXR is specific, but not sensitive.
- CT is very sensitive, but carries ‘risk’.
- Neither should be the main driver for the diagnosis.
- Imaging is variable with emphysema, but poorly corelated with FEV.
- Extensive emphysema can exist with normal FEV.
- Severe FEV can co-exist with minimal emphysema on CT.
- Useful in advanced disease to review non-COPD disease - bronchiectasis, fibrosis, cancer.
What are the goals of COPD assessment?
To determine:
- The level of airflow limitation
- The impact of disease on the patient’s health status
- The risk of future events (exacerbations, hospital admissions, or death)
In order to guide therapy.
Describe group A management of COPD.
Describe group B management of COPD.
Describe group C management of COPD.
Describe group D management of COPD.
How is treatment escalated based on symptoms and risk in COPD?
- Go to the right along the x axis if the patient is more breathless.
- Go up the y axis if they have greater risk.
- You should escalate in this order.
Describe the prescription of oxygen therapy for COPD patients.
