Respiratory Flashcards
What are the antigens on the influenza virus?
Haemagglutinin and Neuraminidase antigen - they attach to the respiratory epithelium. This is what we develop immunity against.
Features of influenza
fever, limb ache, headache, sore throat, dry cough
Influenza Mx?
paracetamol, bed rest, maintain fluids
What is COPD?
poorly reversible airflow limitation, it is progressive and associated with persistant inflammation in the lungs.
Causes of COPD
smoking, pollution, A1 antitrypsin deficiency
How does smoking cause COPD?
Mucous gland hypertrophy in large airways causes increased neutrophils/macrophages/lymphocytes which release inflammatory mediators that break down connective tissue.
Discuss the 2 pathophysiologies of COPD?
1) CHRONIC BRONCHITIS - airway narrowing with hypertrophy and hyperplasia of mucous secreting glands and oedema. Columnar epithelium –> Squamous.
2) EMPHYSEMATOUS - loss of elastic recoil meaning alveoli close on expiration - airflow limitation and trapping.
What are pink puffers?
Predominant emphysema - breathless, not cyanosed
What are blue bloaters?
Predominant bronchitis - hypoventilate, cyanosed, oedematous, CO2 retention (bounding pulse.)
COPD features?
cough, sputum, wheeze, breathless, years of smokers cough, worse with infections.
COPD signs on examination?
Breathless, increased expiration time, poor chest expansion, lungs hyperinflated, barrel shaped chest, use of accessory muscles.
What cells are involved in COPD inflammation?
Macrophages, neutrophils, CD8 cells.
COPD complications?
cor pulmonale, respiratory failure.
Investigations for COPD?
Lung function test - progressive airflow limitation
CXR - lungs hyperinflated, flat diaphragm
CT - emphysematous bullae
Bloods - polycythaemia?
ABG - hypoxia, hypercapnia
ECG/ECHO
Stages of COPD?
- MILD - Chronic cough. FEV1/FVC <70%, FEV1 > 80%
- MOD - Breathless on exertion, FEV1/FVC <70%, 50%
- Severe - breathless on minimal exertion
- v severe - breathless at rest
What is FEV1 and FVC?
FEV1 = forced volume expired in 1 second FVC = total volume expired FEV1/FVC = ratio to measure airflow limitation - <75% = airflow limitation, >75% = restrictive lung disease
General measures for COPD patients?
STOP SMOKING! influenza and pneumococcal vaccine.
Medical therapy for COPD?
- SABA + SAMA (salbutamol + tiotropium bromide)
- Prednisolone
- O2 therapy - guided by blood gas measurements
Features of a COPD exacerbation?
worsened cough and breathlessness, sputum, wheeze, hypoxia and confusion.
Common cause of a COPD exacerbation?
H.Influenzae
Treatment of an exacerbation of COPD?
- Give O2 (aim for SpO2 of 88-92%)
- Bronchodilators (Salbutamol and ipratropium bromide)
- Prednisolone 40mg
- Co-Amoxiclav
Other: LMWH to avoid DVT, escalate with Aminophylline, ventilate with BiPAP.
What is OSA?
repeated cessation of breathing for >10 seconds due to obstructed upper airway during sleep.
RF for OSA?
obesity, alcohol, hypothyroid
OSA features?
loud snoring, daytime sleepiness
OSA Ix?
measure O2 sats whilst sleeping
OSA Mx?
lose weight, remove tonsils, CPAP whilst sleeping
What is bronchiectasis?
Abnormal and permanent dilation of central and medium sized airways. Results in impaired clearance of bronchial secretions –> poolings which cause secondary bacterial infections and inflammation.
Causes of bronchiectasis?
post infective, CF, AIDS
Features of bronchiectasis?
chronic productive cough, recurrent infections, thick foul sputum, breathless, wheeze
What do you hear on auscultation of a patient with bronchiectasis?
coarse crackles
Ix for bronchiectasis? what would these show?
CXR - dilated bronchi and thickened walls, cysts?
CT - airway dilation, walls thickened, cysts
sputum culture
Mx of bronchiectasis?
stop smoking, physio for sputum clearance
influenza and pneumococcal vaccine
how to manage an exacerbation of bronchiectasis?
resp physio (mucus clearance)
ABx - flucloxacillin
bronchodilators
steroids
What causes CF?
autosomal recessive condition with mutation in CFTR transmembrane protein which is resposible for transporting CL-. Mutation causes increased salt content of the mucus = increased viscosity.
Commonest mutation = deltaF508