Thoracics Flashcards
Causes of reduced DLCO
Anaemia Pulmonary hypertension Pulmonary fibrosis COPD Diffuse pneumonia
Causes of high DLCO
Pulmonary haemorrhage
Asthma-increased lung vol and inflammation
Cxr upper lung distribution opacities
Sarcoidosis
Silicosis
Langerhan cell histiocytosis
Reactivated TB
Lower zone opacities on plain film
Heart failure
Pulmonary fibrosis
Asbestosis
Pneumonia
FDG in pet stands for
18 fluorodeoxyglucose
Taken up by metabolically active malignant cells and trapped
Sensitivities 95% mediastinal LN malignancy
Spec 80%
False neg in low grade tumours like adenocarcinoma in situ, less than 1cm, carcinoid
What is the role of PET-CT in lung Ca
?
Known or suspected lung cancer staging evaluation
Simultaneously acquired pet and ct images
Higher spec and sens than either alone
Expensive
Radiation
Detects 10-20 percent of patients with known or suspected lung cancer who was otherwise thought to be a candidate for surgery
Still need a tissue diagnosis if positive pet
Role of exhaled nitric oxide levels in asthma?
Noninvasive
Reflects active airway inflammation
Correlates with airway eosinophilia
Assess adherence to therapy
ABPA is from sensitisation to
Aspergillus fumigatus
Diagnose ABPA with-
Elevated serum total and specific aspergillus IgE
Positive skin test to aspergillus fumigatus
Eosinophilia
Also see proximal bronchiectasis
Mucus plugging –> atelectasis
Long term get pulm fibrosis if not controlled
Mechanism of leukotriene modifying drugs eg minteleukast
Modest anti inflammatory and bronchodilator effect
Block receptors or production by inhibiting 5-lip oxygenase
Can cause mood and psych side effects
Causes of increased DLCO
Polycythemia
Asthma
Pulmonary haemorrhage
Left to right shunt
Useful to differentiate asthma from emphysema, evaluate restrictive, early stages pulm hypertension
DLCO USUALLY NORMAL IN CHRONIC BRONCHITIS and TLC NORMAL compared with emphysema where increased
What is a better predictor of survival in copd? Hyperinflation or FEV1?
Hyperinflation
Workup for ILD
ANA, RF
ANCA if suspect vasculitis
Anti-GBM antibodies if suspect
ECG-? pulmonary hypertension suspected
Upper zone predilection ILD
sarcoid pulmonary langerhan cell histiocytosis hypersensitivity pneumonitis silicosis berylliosis RA (necrobiotic nodular form) Ank spond
BAL findings in sarcoidosis
lymphocytosis; CD4:CD8 ratio over 3.5 most specific of diagnosis
COP BAL findings
foamy macrophages
decreased CD4:CD8 ratio
Respiratory disease in RA
pleurisy
+/- effusion
ILD
necrobiotic nodules (non pneumoconiotic intrapulmonary rheumatoid nodules)
Caplan’s syndrome (rheumatoid pneumoconiosis)
pulmonary hypertension secondary to rheumatoid pulmonary vasculitis
organised pneumonia
upper airway obstruction due to crico-arytenoid arthritis
Lung involvement in SLE
-pleuritis +/- pleurisy most common
-atelectasis
pulmonary vascular disease
pulmonary haemorrhage
uraemic pulmonary oede,a
infectious pneumonia
chronic progressive ILD uncommon
lungs in polymyositis/dermatomyositis
ILD in 10% of all these patients
Lung involvement in Sjogren’s
general dryness and lack of airway secretion-->cough and hoarseness Lymphocytic interstitial pneumonia Lymphoma Bronchitis Bronchiolitis obliterans
LAM has what picture on PFTS
obstructive
Upper zone fibrosis predominant
Extrinsic allergic alveolitis Silicosis Sarcoidosis Coal workers pneumconiosis Histiocytosis TB Ank spond
Lower zone fibrosis
IPF
Most CT disorders not ank spond
drug induced: amiodarone, bleomycin, methotrexate
asbestosis
CXR staging of sarcoidosis- 1 to 4… GO!
- BHL
- BHL + infiltrates
- Infiltrates
- Fibrosis
ACE sens 60 spec 70 Hypercalcaemia in 10% May have an ACE role in monitoring disease activity Spirometry: restrictive Biopsy: noncaseating granulomas
Hyperkalaemia- quick run through causes including drug causes.
AKI Drugs: K sparing diuretics, BETA BLOCKERS, ACE, ARB, spiro, ciclosporine, heparin (inhibit aldosterone secretion) Metabolic acidosis Addisons Rhabdo massive blood transfusion
IPF negative prognostic markers
Male age over 50 mod-severe spirometry and DLCO extensive smoking history neutrophilia on BAL extensive honeycomb on HRCT mod-sev dyspnoea on exertion desaturation to below 88% on 6mwt
What is the most powerful tool for reducing cigarette consumption?
Price - in large increments ie 10%
Criteria for diagnosis ABPA- need 6 or more? (8)-
Asthma Fleeting pulmonary shadows Aspergillus precipitans IgE over 1000 RAST for aspergillus Positive skin prick test (type 1) Eosinophilia Central bronchiectasis
Minor criteria are:
- Aspergillus in sputum (DO NOT NEED TO CONFIRM DIAGNOSIS)
- Expectoration black/brown mucus plugs
- Delayed skin reaction to aspergillus Ag (type 3 reaction)
What is a normal residual volume?
About 25% of TLC
If see reduced FVC, could be due to restrictive defect, or could also be due to hyperinflation causing increased residual volume.
What effect does Carboxyhaemoglobin or pCO2 alveolar have on DLCO/
CO will reduce because reduction in diffusion gradient
increase CO2 in alveolus will increase TLCO because reduce PaO2- less competition for binding sites
Classes of CFTR mutation and which one is DF506 and which is G551D?
I - no synthesis CFTR
2- Defective maturation and premature degradation and what is there does not work well- delta F 508
3- Abnormal ion channel regulation eg ATP binding- channels there but not working eg G551D
4- Defective conduction of chloride- some chloride still gets through
5- reduce number of transcripts but the ones there are working
6-accelerated turnover
When can you use Ivacaftor?
For G551D mutation (class 3)- corrects the defect in the existing channel
IMproves FEV1, reduces exacerbation risk, causes weight gain
Which to bugs if colonised in CF cause worse transplant outcomes?
Burkholderia ceppacia Mycobacterium abscessus (not MAC)
What are some different BAL cell patterns? What is normal?
Normal is over 95% alveolar macrophages
CD4/8 over 3.5–>sarcoid
CD4/CD8 under 1 –>hypersensitivity pneumonitis
Eosinophils over 25% in eosinophilic pneumonia, fungal/parasitic
Neuts +++–>in IPF
Lymphocyte predom –>sarcoid, hypersens pneumonitis
Foamy Macrophages, mixed pattern increased cells and ratio under 1–> COP
Primary offender in lung destruction in COPD?
Human leukocyte elastase
Also proteinase 3, macrophage derived matrix metalloproteinases, plasminogen activator, cigarette smoke free radicals
What is the significant of microalbuminuria in COPD?
associated with hypoxaemia independent of other risk factors
What is the significance of centri-acinar, panacinar, distal acinar/paraseptal patterns of emphysema?
Centri- cig smoking with upper lobe predom
Panacinar with homozygoous alpha 1 AT- lower lobe predom
Distal/paraseptal- bullae formation but no obstruction
In mild vs mode to severe emphysema, what is the predominant pathological mechanism?
Mild- bronchiolar disease
Mod-Sev- loss elastic recoil
What predict survival in COPD better- hyperinflation or FEV1?
Hyperinflation
What should be the first step in asthmatics being evaluated for ABPA?
Skin prick test- if neg excludes.
if positive, check IgE and aspergillus precipitins
If positive then do aspergillus specific IgE and G
Why is REM so hard in OSA?
Because lose muscle tone–>collapse airways even more!!
Complications of OSA?
MVA Stroke Hypertension Pulmonary hypertension CAD, arrhythmias, HF Insulin resistance and diabetes TAG up All cause mortality increase 2-3 times if AHI over 30 INDEPENDENTLY of other RF Depression
Where is the respiratory centre located?
Bilaterally in the ventrolateral medulla at the caudal fourth ventricle
Causes of central sleep apnoea?
Basically these patients hyperventilate to drive the CO2 down so that there is no stimulus for sleeping ventilationany more:
Hence oximetry not useful
opioids CCF AF Stroke CKD high altitude treated OSA
**If the CO2 is HIGH it is NOT central apneoa- it is sleep related hypoventilation syndrome. See SUSTAINED hypoxaemia - usually 30% total sleep time
When would you need supplemental oxygen while flying?
If sats 88-95% on room air at sea level, may need
Pressure is equivalent of 2500m altitude equivalent, as if breathing 15% oxygen at sea level- gives normal people paO2 53-64% and sats of 85-91%
Remember that A-a is NORMAL in healthy adults at high altitude.
What is COPD diagnosis based on?
History of exposure to smoke or other noxious agents
or
FEV1/FVC
What factors correlate with COPD mortality?
Degree of hyperinflation reflected by IC/TLC
Poor 6MWT
VO2max
BMI
MMRC dyspnoea scale
BODE score (BMI, degree obstruction, dyspnoea score, exercise score on 6MWT)
Hypoxaemic resp failure
All better than FEV1
When is IGRA unreliable in HIV?
CD4 under 100
What is the worst risk of TB reactivation? Adalimumab, Infliximab, Ertanacept or DMARDS?
Adalimumab worst.
DMARDS not really increase, Tocilizumab (anti IL-6), Abatacept (CD80/86), Anakinra (IL-1) no increase over DMARDs
So just the TNF aplhas really.
Which of the TB bugs are the Isoniazid and Rifampicin most important for?
Isoniazid- first two months for the rapidly multiplying
Pyrazinamide for the slowly multiplying
Rifampicin for the sporadically multiplying
Why should you never add a single drug to a failing TB regiment?
Selects out the resistant clone and makes more resistant.
