COPD Flashcards
what is COPD
non-reversible, long term deterioration in airflow caused by damage to lung tissue
difficulty ventilarting lungs and prone to infectoin
when to suspect COPD
long term smoker SOB cough sputum production wheeze recurent resp infections
MRC dyspnoea scale: Grade 1
breathless on strenuous exercise
MRC dyspnoea scale: Grade 2
breathless walking uphill
MRC dyspnoea scale: Grade 3
breathless on flat
MRC dyspnoea scale: Grade 4
stop to catch breath after 100m on flat
MRC dyspnoea scale: Grade 5
unable to leave house to due breathlessness
diagnosing COPD
based on clinical picture + spirometry
COPD spirometry
obstructive picture: FEV1/FVC <0.7
no dramatic response to reversibility testing
severity of airflow obstruction: stage 1
FEV1 >80%
severity of airflow obstruction: stage 2
FEV1 50-79%
severity of airflow obstruction: stage 3
FEV1 30-49%
severity of airflow obstruction: stage 4
FEV1 < 30%
other Ix
CXR FBC BMI sputum culture ECG, ECHO CT
long term Mx stepladder
- SABA or short acting muscarinic
- no steroid response: LABA + LAMA
steroid response: LABA + ICS
long-term Mx options for severe cases
neubulisers theophyline oral muclytic therapy prophylacitc antib at home oxygen therapy
when to use long-term O2 therapy
chronic hypoxia
polycythemia
cor pulmonale
when not to use long term O2 therapy
if they smoke (fire hazard)
COPD exacerbation
acute worsening of symptoms: cough, SOB, wheeze, sputum
usually triggered by viral or bacterial infection
ABG: acidosis with raised PCO2
suggest they are acutely retaining
respiratory acidosis
ABG: raised bicarbonate
indicates they chronically retain CO2 (kidneys produce more bicarb to balance acidic CO2)
in acute exacerbation kidneys can’t keep up and still become acidotic
t1 resp failure
low pO2 and normal PCO2
t2 resp failure
low PO2
raised pCO2
oxygen therapy consideration in COPD
too much O2 in chronic retainer can depress resp drive - slow down RR and retain more CO2
venturi masks
deliver specific percentage of oxygen
% can be carefully controlled
If retaining CO2 aim for O2 sats of…
88-92% titrated by venturi mask
if not retaining CO2 and normal bicarbonate (don’t chronically retain) aim for sats of…
> 94%
medical treatment of exacerbation: at home
prednisolone 30mg OD
regular inhaler/neb
antibx if infection
medical treatment of exacerbation: in hosp
nebulised bronchodilator
steroids
antib
physio
medical treatment of exacerbation: severe. non responsive
IV aminophyline
NIV
intubate
doxapram
what should patients with frequent exacerbations be offered
corticosteroids
antibiotics (advise only to be used if purulent sputum)
