Bloody Cough Flashcards
what is massive haemoptysis?
most commonly over 250mls/24 hours
where do 5% of haemoptysis originate from?
pulmonary arterial system: high compliance low pressure system and rest from bronchial arteries (3-8th thoracic levels) high pressure
mechanism of bleeding of bronchial arteries?
inflammation of mucosa, bronchial arteries hypertrophy and proliferate becoming more amenable to erosions and bleeding
other mechanism of bleeding?
necrosis and infarction of lung parenchyma (PE), invasion of blood vessels by tumour, rupture of distended pulmonary capillaries mitral stenosis and LVF, intracavitary anastomoses fungal problems, vasculitis of pulmonary vessels
causesof haemoptysis
lung cancer, kaposi sarcoma, TB, bacterial pneumonias, bronchiectasis, bronchitis cystic fibrosis PE,SLE,
how does cough pathophysiology work?
intake of noxious stimulus causes mechanosensory receptors Adelta fibres and chemosensory fibre c fibres through afferent limb of vagal nerves to botzinger ventral respiratory group in midbrain. efferent part causes muscular contraction leading to intake of air with strain against a closed glottis and forced expiration
common causes of cough
postnasal drip, asthma, GERD, infection, COPD, blood pressure drugs
less common but very important causes of cough?
aspiration, bronchiectasis, bronchiolitis, cystic fibrosis, lung cancer, sarcoidosis and interstitial lung disease
which drugs cause cough?
ACEi and beta blockers
what to ask for haemoptysis?
is it mixed in with sputum, catemenial heamoptysis (periods),features of asthma, how much sputum is produced, fever, chest pain weight loss, rashes joint pain vasculitis,
find risk factor for PE and HIV, travel history, ask about drug history
What is mortality rate of massive haemoptysis?
38%
how does death happen from massive haemoptysis?
asphyxiation ( not getting enough oxygen)
when reassessing when to do bronchoscopy?
unstable, if stable then CT
pathophysiology of TB
airborne droplets inhaled and deposited in terminal airspaces. macrophages ingest bacilli and they replicate within endosomes
transported to regional lymph node
how fast does TB divide?
16-20 hours
what does bacillus not have?
phospholipid outer membrane
what does bacillus not have?
phospholipid outer membrane
histology of TB?
granulomatous inflammation with central necrosis caseation. rim of lymphocytes, fibroblasts and central infected macrophages giant cells and AFBs in granulomas
what stain for tb
ziehl-neelsen stain and auramine rhodamine
OTHER FORMS of TB?
skeletal- 15-30%
genitourinary- pus in urine sterile pyuria
Enteritis- weight loss, diarrhoea, blood in stools
CNS- meningitis, archnoiditis, tuberculoma, spinal cord compression extension of discitis
treatment for TB?
2 months RIPE
followed by isoniazid and rifampicin for 4 months
CNS involvement then 12 months
side effects of pyrazinamide?
joint pain, nausea and vomiting
isoniazid side effects?
peripheral neuropathy, fever, and optic neuritis
ethambutol side effects
peripheral neuropathy, optic neuropathy, hout,
What do you see in inactive or latent TB?
calcified granulomas
what else will you see in TB CT?
tree-in-bud
what is incidence?
how many people develop disease over given time/ number of people at risk of developing disease over given time
what is person time
number of people in the study and the amount of time each person spends in the study
what is an assumption with person time?
assumes disease probability during study period is constant, but often invalid as many chronic diseases increase with age
equation of prevalence and incidence?
prevalence= incidence x disease duration
cohort study?
group of individuals free from disease with an exposure of interest
Strengths of cohort?
more than one disease can be measured
offers some evidence of cause-effect
good when exposure is rare
can calculate incidence and risk
disadvantages of cohort?
loss to follow up
requires large sample long duration and expensive
less suitable for rare disease
less suitable for diseases with long latency
does not eliminate confounding
what is relative risk?
incidence of disease among exposed/ incidence of disease among non-exposed
