Week 5 - Restrictive and Obstructive Lung Disease Flashcards
4
What does TLCO measure?
Measures how well oxygen and carbon dioxide are transferred between the alveoli (air sacs) and the blood in the pulmonary capillaries
How does KCO differ from TLCO?
KCO is TLCO that is adjusted for alveolar volume - i.e. measures the transfer of CO in alveoli that are ventilated.
Both are reduced by V/Q mismatch conditions.
KCO is not diminished by extra thoracic restrictive conditions -whereas TLCO is - therefore helps you distinguish the cause.
Why does the FEV1:FVC ratio increase in restrictive lung disease?
Restrictive lung disease - lungs are smaller - therefore FVC decreases, but less than FEV1 - therefore ration increases.
What can cause restriction to the lungs?
Damage to the parenchyma (inflammation and fibrosis) - e.g. pulmonary fibrosis, sarcoidosis, pneumoconiosis
Pleural disease (P Eff, pneumo/haemothorax, calcification, mesothelioma)
Obesity
Chest wall disease (NMD, palsy, kyphosis/scoliosis)
In lung fibrosis - where is the primary site of injury?
The interstitium - between the cells and basement membrane - thickens and stiffens = reduced transfer of O2
What are the RF for lung fibrosis?
How can Sx for lung fibrosis present?
SOB - worsening progressively
Cough
Fatigue
Weight loss
Crackles
How can you differentiate an AI cause for lung fibrosis?
AI / Collagen vascular - can also have difficulty swallowing, cold hands, joint pains, weight loss, skin rash
What are the clinical signs of lung fibrosis?
Clinical signs à ↑ RR, Tachypnoea, Dyspnoea, Clubbing, CVS - ↑ JVP, perip oedema, loud P2 heat (signs of cor pulmonale). Low O2 sats – desats on exertion.
If AI can have – RA, skin changes (telangiectasia, Raynaud’s), joint signs, eye signs
What is it called when we dont know what is causing fibrosis of the lungs?
Idiopathic pulmonary fibrosis (IPF)
M>F
What is the average length of surivival from diagnosis of IPF?
2.5-3.5 years
Often sudden exacerbation (infection) & decline – dramatic decrease in LF à death
What does honeycombing and bronchial dilation on CT suggest?
IPF
What does spirometry show in IPF?
What Rx is given for IPF?
Symptomatic
Antifibrotic
Palliative (if young poss transplant)
What investigations can you do to investigate whether a P has pulmonary fibrosis or not?
Bloods - FBCs, U&Es, AI screen
CXR
HRCT
Spirometry
TLCO and KCO
What type of respiratory failure is caused by pulmonary fibrosis?
T1
Which type of pulmonary fibrosis is associated with AI or collagen vascular disease?
Non-Specific Interstitial Pneumonia
(is actually pneumonitis not a pneumonia)
How does NSIP differ from IPF in terms of Ps?
Younger Ps affected
Not associated with smoking
M = F (whereas in IPF - M>F)
Extensive ground glass changes, small lungs and reticule-nodular changes on imaging suggests?
NSIP
Which collagen-vascular diseases can cause NSIP?
Scleroderma
RA
SLE
Why is it important to distinguish IPF from NSIP?
NSIP has a better prognosis and responds to anti-inflammatories whereas IPF won’t.
How is NSIP managed?
Which drugs can cause pulmonary fibrosis?
Amiodarone
Nitrofurantoin
Bleomycin
+ more
Erythema nodosum
Bilateral hilar lymphadenopathy
A P with
SOB
Cough
Fever
Night sweats
Weight Loss
Arthralgia
Reduced appetite
Myalgia
Anterior uveitis
Lymphadenopathy
Erythema Nodosum
Bilateral hilar lymphadenopathy
Could have?
Pulmonary sarcoidosis
DDs = TB, Vasculitic conditions, lymphoma
What is sarcoidosis?
Multisystem granulomatous disease – unknown aetiology (thought poss infection, dusts, minerals, beryllium, congenital – may be immune response to inhaled antigen)
Creates non-caseating granulomas – often in multiple organs. Primarily affects the lungs
May resolve spontaneously
OR may progress to pulmonary fibrosis
What is the average of age of sarcoidosis?
20-50
What types of sarcoidosis can you have?
Acute (Loefgren’s), chronic and asymptomatic
What finding in the bloods that can suggest sarcoidosis?
Hypercalcaemia
Abnormal LFTs
Which other organ systems can be affected by sarcoidosis?
Pretty much any
How is sarcoidosis diagnosed?
Clinical + radiological + histological features
How is pulmonary sarcoidosis staged by CXR?
0-IV
0 = normal lungs
IV = bad lungs
Non-caseating epithelioid-cell granulomas + multi-nucleated cells with asteroid bodies, Schumann bodies and bifringent crystalline particles + minimal necrosis - suggests what?
Sarcoidosis
Why do you get hypercalcaemia and hypercalciuria in sarcoidosis?
Vit D is increased by macrophages in the granulomas => inc Ca
What is the outcome of sarcoidosis?
How is sarcoidosis managed?
Pleural effusion
How much pleural fluid is produced and cycled through the pleura each day?
1L
What types of fluid can you get in the pleural space?
Transudate
Exudate
How can you differentiate between transudate and exudate?
Exudate =
Fluid protein : serum protein > 0.5
Fluid LDH : serum LDH >0.6
Fluid LDH - >2/3rds ULN of normal serum LDH
Therefore - exudate is high in protein and LDH
Transudate =
Fluid protein : serum protein <0.5
Fluid LDH : serum LDH <0.6
Fluid LDH < 2/3rds ULN of normal serum LDH
What causes exudate in the pleura?
Malignancy
Infection
AI disease
Chylothorax (blocked lymphatics)
What causes transudate in the pleura?
Congestive cardiac failure
Low albumin - often caused by nephrotic syndrome or liver failure
What are the clinical signs of pleural effusion?
What are the RF for spontaneous pneumothorax (i.e. primary pneumothorax)?
Tall and thin
Asthma
Collagen vascular disease
What can cause secondary pneumothorax?
COPD
Pulmonary fibrosis
Cystic fibrosis
How is pleural effusion managed?
What can cause chest wall disease?
What can cause mixed obstructive and restrictive lung disease?
Smoking = emphysema and pulmonary fibrosis
Pulmonary sarcoidosis
Obesity in smokers
When is TLC reduced and when is it increased?
TLC = reduced in restrictive disorders
Increased in obstructive disorders (air trapping)
What do the following all do to TLCO?
- V/Q mismatch
- PE
- Emphysema
- Interstitial lung disease
- External lung restriction
Decrease TLCO
What does inc pul capillary BV (e.g. high cardiac output, polycythaemia, pulmonary haemorrhage) do to TLCO?
Increases it
What is KCO used to differentiate?
Can differentiate whether restriction is intra or extrathoracic. If extra-thoracic restriction, KCO is not reduced (but TLCO will be).
