Resp Flashcards
Cells producing surfactant?
Type 2 alveolar epithelial cells
FEV1
Volume of gas expired in first second of forced expiration
FVC
Total volume of gas expired on forced expiration
Normal FEV1:FVC?
70-80%
Obstructive vs restrictive FEV1/FVC pattern?
Obstructive is a preserved FVC with a reduced FEV1:FVC - obstruction limits the amount in 1 second but the capacity is not restricted
Restrictive is a preserved FEV1:FVC but with a reduced FVC - they can blow lots of air out but the total capacity is limited
Obstructive vs restrictive airway diseases
Obstructive - asthma/COPD
Restrictive - PF/obesity/neuromuscular/pleural disease
Diffusion impairment in hypoxaemia?
Pulmonary oedema or ILD
Dissociation curve to the right?
High temperature
Acidosis
Hypercapnia
Increased 2,3-GPD - encourages offloading of oxygen to tissues
Altitude
Dissociation curve to the left?
Alkalosis
Low temperature
Hypocapnia
Carboxyhaemoglobin
Foetal haemoglobin
Variable and reversible airflow obstruction?
Asthma
Exhaled nitric oxide concentration in asthma?
Increased, >40 parts per billion
Do this in all suspected asthmas over 17 years
In children only do it if the spirometry is normal/not as expected
Common Ig response in asthmatics?
IgE
Testing for specific IgE responses?
RAST
Monoclonal antibody sometimes used in severe allergic asthma? What does it bind to?
Omalizumab
IgE
Asthma not controlled on SABA?
Add low dose ICS
ASthma not controlled on SABA + ICS?
Add LTRA
Asthma not controlled on SABA + ICS + LTRA?
SABA + ICS + LABA +/- LTRA
Asthma not controlled on SABA + ICS + LABA +/- LTRA?
SABA + MART +/- LRTA
Life-threatening asthma features?
Hypoxaemia
PEFR<33%
Exhaustion
Bradycardia/arrhythmia
Hypotension
Silent chest
Altered consciousness
Poor respiratory effort
Cyanosis
ITU referral in asthma?
Deteriorating PEFR despite Rx
Persistent or worsening hypoxia
Rising CO2
Acidosis
Altered consciousness/exhaustion
Resp arrest
FEV1:FVC in COPD?
<70
FEV1 in COPD?
Classically <80% predicted
Most common exaccerbating organisms in COPD?
H flu - most common
Strep pneumoniae
Less common - staph, moraxella
Score for objective measure of COPR prognosis?
BODE
COPD grades of airflow obstruction (FEV1)
Mild - at least 80%
Mod - 50-79% predicted
Severe - 30-49% predicted
Very severe - <30% predicted
COPD causes
Smoking
A-1 antitrypsin
Coal
Cotton
Cement
Cadmium
Grain
“Asthmatic/steroid responsive” features in COPD
Any previous, secure diagnosis of asthma or of atopy
Higher blood eosinophil count - note that NICE recommend a full blood count for all patients as part of the work-up
Substantial variation in FEV1 over time (at least 400 ml)
Substantial diurnal variation in peak expiratory flow (at least 20%)
Treatment for COPD WITHOUT “Asthmatic/steroid responsive” features”
LABA + LAMA + SABA for bronchodilation
Treatment for COPD WITH “Asthmatic/steroid responsive” features”
LABA + ICS
You can add LAMA
Transplant basic criteria in COPD?
Under 65
FEV1 and DCLO <20%, history of severe hospitalisaton
+/- cor pulmonale despite O2 therapy
Transplant basic criteria in COPD?
Under 65
FEV1 and DCLO <20%, history of severe hospitalisation
+/- cor pulmonale despite O2 therapy
Normal alpha 1 AT genotype?
PiMM
Abnormal alpha 1 AT genotypes?
PiMZ - carrier - may pass on to children but low risk of lung disease in non-smoker
PiSS - 50% A1AT levels
PiZZ - most severe deficiency and most likely to manifest disease - 10% A1AT levels
What is alpha 1 AT?
Protease inhibitor
Effects of A1AT deficiency?
Emphysema, mostly lower lobes
Liver: cirrhosis and HHC in adults, cholestasis in children
LTOT criteria?
pO2 <7.3 on at least two separate occasions
OR
<8.0 with evidence of PHTN, polycythemia, peripheral oedema or nocturnal hypoxaemia
Gram +ve cocci in COPD?
Moraxella
Most common organism in central line infections?
Staph epidermidis