Respiritaory Flashcards
Causes of fibrosis / ILD?
Idiopathic:
- IPF
Exposure related:
- Asbestosis, silicosis, coal miners lung
Alergic related:
- chronic hypersensitivity pneumonitis
Autoimmune related:
- RA, systemic sclerosis
Medication:
- BLeomycin (most damaging, almost all get ILD), trimethoprim, methotrexate
Sarcoidosis
Causes of bronchiectasis?
CF and non CF causes
Non CF causes can be divided into focal and diffuse pattern
- Focal: Forign body, local cancer causing obstruction
- Diffuse:
-> Infective: cecurrent pneumo as child
-> Autoimmune: CVID, Primary cilliary dyskinesia
-> CTD: RA
Causes of cavitating lung lesion?
Infective:
- TB, aspergilosis
Infiltrative:
- Sarcoidosis
Autoimmune:
- GPA, RA
Malignant:
- Squamouse cell carcinoma, cavitating pul mets
Vascular:
- PE infarction
Causes of clubbing?
Cardiac causes such as cyanotic heart disease
Resp causes such as CF, bronchiectasis, IPF, lung cancer, Lung abscess
Hepatic causes such as cirrhosis with cardiopulmonary syndrome
(COPD does not cause clubbing in isolation)
Causes of an obstructive defect on PFTs?
COPD / alpha 1 antitripsin deficiency
Ashthma
Bronchiectasis or CF
Bronchiolitis
Causes of obstructive defect with and without reversibility?
Reversible
- Asthma
- COPD (can be reversible or not fully reversible)
Non reversible:
- Bronchiectasis / CF
- COPD
Causes of restrictive defect on PFT?
Parynchymal disease:
- ILD (which can be due to numerous aetiologies)
Neuromuscular disease
- Myopathies
- Neuropathies
- NMJ disease
Congestive cardiac failure
Obesity (functional restriuction)
What are the cutoffs for PFTs (including spirometry, DLCO, lung volumes)?
- FEV1/FVC ratio <0.7 (70%) indicates obstruction
- FEV1 <0.8 (80%) is reduced
- FVC <0.8 (80%) is reduced
Post bronchodilator response >10% change in FEV1 OR - FVC is significant reversibility - DLCO <0.8 (80%) is reduced
- TLC <80% is reduced (consistent with restriction), >120% is increased (consistent with hypoerexpansion)
- RV <80% is reduced (consistent with restriction), >120% is increased (consistent with gas trapping)
Dont worry about KCO
How to interpret PFTs?
Look at FEV1/FVC ratio pre bronchodilator (not the percentage as this would be a percentage of a ratio):
- if <0.7 then obstruction. If >0.7 then not obstruction
Then look a t FEV1 and FVC pre bornchodilator percentage
- If Either or both are <0.8 then this is reduced and may suggest restriction
Then look at post bronchodilator FEV1 and FVC:
- If there is a >10% change in EITHER or BOTH then this is significant reversibility
(By now you should know obstructive with or without reversibility, or restrictive without evidence of obstruction, or mixed)
Then look at DLCO.
- If <0.8 then reduce. THere are many causes
Then look at lung volumes:
- If TLC <0.8 and restrictive spiro then confirms restriction
- If TLC and RV >120% and obstructive then indicates hyperexpansion and gas trapping
What CTD cause ILD?
What autoimmune screen for ILD patients?
Most common CTD causes:
- RA (either via methotrexate or directly)
- Systemic sclerosis
Other CTD causes:
- Idiopathic inflamatory myopathies (dermatomyositis, Polymyositis, antisynthetase syndrome)
- SLE
- Sjrogens syndrome
Antibody panel:
- RA: RF, anti-CCP
- Systemic scerlosis: anti-SCL 70 (ant topoisomerase), anti RNA polymerase
- Dermatomyositis and polymyositis: anti jo1 (mainly), but also anti SRP and anti Mi2
- SLE: anti dsDNA, anti smith, anti-U1 RNP
- Sjrogerens - Anti Ro, anti La
Causes of apical fibrosis? Causes of basal fibrosis?
Apical:
- Exposure related: Silicosis
- Sarcodiosis
Basal:
- IPF
- CTD related (RA and systemic sclerosis)
- Drugs (methotrexate included)
What are teh two types of systemic sclerosis and which one causes ILD?
Limited cutaneous systemic sclerosis (formally CREST)
Diffuse cutaneous systemic sclerosis (causes ILD)
Features of CREST (limited cutaneous systemic sclerosis)?
Calcinosis
Raynauds
Esophageal dysmotility
Sclerodactyly
Telangectaia
What is systemic sclerosis sine scleroderma?
This is rare systemic scleropsis subtype without skin manifestation, but with the usual internal organ manifestations (inc ILD) and raynauds
Signs of systemic sclerosis?
Hands / nails:
- Puffy fingers (early inflam changes) or sclerodactyly (fibrosis phase) with fissures and scars
- Nail fold capileries
- Raynauds
- Digital ulcers
Face:
- Telangectasia on face chest and arms
- Perioral furrowing
- Microstomia (three finger rule)
- Beaked nose
Lung:
- ILD
- Pul HTN
- Features of cardiomyopathy
Renal:
- HTN (need to check BP)
- GN (need to check urinalysis for protinuria)
Other:
- Calcinosis affecting digits and extensor surfaces of limbs. Can cause chalky white discharge
ILD findings on HRCT?
ILD findings on CXR?
HRCT:
- UIP (Most common, associated with IPF) - honeycombing and nodular reticular changes with traction bronchiectasis and bronchioliectasis. Has a basal and subpleural predominance
- NSIP (second most common, associated with CTD) - subpleural sparing ground glass changes
CXR:
- Widespread reticular or nodular reticular changes throughout both lung feild, without evidence of Fluid overload
Differentials of a wet and dry cough?
Superative lung conditions:
- Bronchiectasis / CF
- COPD (mainly bronchitis)
- Acute processes (wont be present in exam):
-> Infection (CAP, IECOPD, IEILD, IE Asthma)
Causes of dry cough:
- ILD
- Asthma
- Lung cancers / smokers (unless ass COPD)
