COPD Flashcards
COPD
non reversible, long tern deterioation in air flow cuased by damage to lung tissue. this causes obstruction- more difficult to ventilate. prone to infections.
not significantly reversible with bronchodilators.
susceptible to exacerbations (infective)
presentation of COPD
long term smoking chronic SOB cough sputum production wheeze recurrent respiratory infection
MRC dyspnoea scale
This is a 5 point scale that NICE recommend for assessing the impact of their breathlessness:
Grades:
Grade 1 – Breathless on strenuous exercise
Grade 2 – Breathless on walking up hill
Grade 3 – Breathless that slows walking on the flat
Grade 4 – Stop to catch their breath after walking 100 meters on the flat
Grade 5 – Unable to leave the house due to breathlessness
COPD diagnosis
spirometry: obstructive picture
overall lung capacity
FEV1/FVC <0.7
Reversibility test
Beta 2 agonist (salbutamol)
The severity of the airflow obstruction can be graded using the FEV1:
Stage 1: FEV1 >80% of predicted
Stage 2: FEV1 50-79% of predicted
Stage 3: FEV1 30-49% of predicted
Stage 4: FEV1 <30% of predicted
other investigations f COPD
spirometry post-BD CXR BMI FBC mMRC? CAT sputum spO2 SPEF CT chest ECG +/- echo TLco Alpha-1 antitrypsin
CXR (rule out lung cancer) FBC (polycythemia in response to chronic hypoxia) BMI sputum culture ECG (heart function) CT thorax (fibrosis) serum alpha-1-antitrypsin TLCO
COPD long term management
- pneumococcal
- annual flu vaccine
- beta-2-agonist (salbutamol) or short acting antimuscarining (ipatropium bromide)
- if they do not have asthmatic or steroid responsive fetures= LABA and LAMA
if asthmatic/steroid LABA plus ICS (fostair, symbicort)
more severe:
Nebulisers (salbutamol and/or ipratropium)
Oral theophylline
Oral mucolytic therapy to break down sputum (e.g. carbocisteine)
Long term prophylactic antibiotics (e.g. azithromycin)
Long term oxygen therapy at home
exacerbation of COPD
ABG: co2 = carbonic acid = acidic. low PH, raised O2= retaining co2
raised bicarbonate indicates chronically retaining co2
respiratory failures
Low pO2 indicates hypoxia and respiratory failure
Normal pCO2 with low pO2 indicates type 1 respiratory failure (only one is affected)
Raised pCO2 with low pO2 indicates type 2 respiratory failure (two are affected)
oxygen therapy in COPD
too much o2 in someone who is prone to reatining co2 can depress their respiraotry drive.
venturi mask (allows some oxygen to leak out of the side so that normal air can be inhaled too)
Venturi masks deliver 24% (blue), 28% (white), 31% (orange), 35% (yellow), 40% (red) and 60% (green) oxygen.
oxygen saturation
If retaining CO2 aim for oxygen saturations of 88-92% titrated by venturi mask
If not retaining CO2 and their bicarbonate is normal (meaning they do not normally retain CO2) then give oxygen to aim for oxygen saturations > 94%
treatment of COPD exacerbation
at home:
Prednisolone 30mg once daily for 7-14 days
Regular inhalers or home nebulisers
Antibiotics if there is evidence of infection
in hospital:
Nebulised bronchodilators (e.g. salbutamol 5mg/4h and ipratropium 500mcg/6h)
Steroids (e.g. 200mg hydrocortisone or 30-40mg oral prednisolone)
Antibiotics if evidence of infection
Physiotherapy can help clear sputum
severe cases not responding to tx:
IV aminophylline
Non-invasive ventilation (NIV)
Intubation and ventilation with admission to intensive care
Doxapram can be used as a respiratory stimulant where NIV or intubation is not appropriate
obstructive respiratory disease
FEV1/FVC <0.7
COPD
- emphysema
- bronchitis
Bronchiectasis
- classically CF
- recurrent infections
- dilation
- destruction of the muscles and elastin in bronchus
- inflammation of ulceration
type I resp failure
hypoxaemia
low o2
normal co2
hyperaemia is resistant to o2 therapy
O2 failure
resp insufficiency
V/Q mismatch (PE)
do not fix with oxygen
type II resp faliure
hypercapnia low o2 high co2 failure to exchange or remove co2 will correct with oxygen therapy
pump failure (HF) fix with oxygen
COPD in type II respiratory failure: 28% venturi masks, aim for sats of 88-92%
key words
- barrel chested
- green/rusty sputum
- strawberry tongue
- whooping cough
Barrel-Chested = COPD
Greenish/Rusty Sputum= Pneumonia
Strawberry Tongue = Kawasaki Disease
Whooping cough= Pertussis
