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