CPC 3 pleural effusion Flashcards
Clinical examination findings suggesting pleural effusion
Dull percussion Decreased vocal fremitus Decreased breath sounds Decreased vocal resonance. Asymmetrical decreased chest expansion.
Mechanisms for the formation of pleural fluid
Increase hydrostatic pressure Decreased oncotic pressure Increased permeability of pleura Increased pulmonary interstitial fluid Movement from other cavities (peritoneal) Vascular rupture into thorax Rupture of thoracic duct
Does cardiac failure cause right, left or bilateral pleural effusions?
Any of the above, though equal ones are slightly more common.
What are the BTS guidelines for how to manage a pleural effusion?
Take a history, clinical examination and CXR. If a transudative causes is likely from the clinical picture, then treat the cause. If not, or if treatment is unsuccessful, refer to a chest physician.
What are Light’s criteria to diagnose exudative pleural fluid?
Pleural fluid is an exudate if one or more of the following
criteria are met:
Pleural fluid protein divided by serum protein is >0.5
Pleural fluid lactate dehydrogenase (LDH) divided by
serum LDH is >0.6
Pleural fluid LDH >2/3 the upper limits of laboratory
normal value for serum LDH.
Basic rule of thumb to differentiate an exudative from a transudative pleural fluid.
Pleural fluid protein >30 g/l has indicated an exudate and
Common causes of exudative pleural fluid.
Parapneumonic effusions,
Malignancy.
Causes of transudative pleural fluid.
All the failures: LVF liver failure (cirrhotic disease), hypoalbuminaemia and peritoneal dialysis. nephrotic syndrome hypothyroidism.
Also:
PE
mitral stenosis
constrictive pericarditis.
If pleural fluid has NT-proBNP level of >1500, what does this mean?
Suggests cause of transudative effusion is cardiac failure.
What does a pleural fluid pH
Malignant effusion, pleural infection, connective tissue disorder esp rheumatoid arthritis, TB or oesophageal rupture.
If pleural fluid glucose is low what is likely to be the cause?
Infection, arthritis or cancer:
complicated parapneumonic
effusions, empyema, rheumatoid pleuritis and pleural effusions
associated with TB, malignancy and oesophageal rupture
Pleural amylase can be useful when?
in suspected cases of oesophageal rupture or effusions associated with pancreatic diseases.
Microbiology of community acquired pneumonia
Strep spp are more than half.
The rest are Staph aureus, enterobacteriaceae, or anaerobes.
Microbiology of HAP
Staph (25% MRSA)
Gram neg aerobes e.g. E. coli, Pseudomonas and Klebsiella.
Anaerobes.
Routes by which bacteria can enter the pleural space.
1) Across the pleura from the adjacent lung.
2) Via visceral pleural defects of fistulae e.g. in cancer, necrotising pneumonia etc.
3) Haematogenous spread
4) Penetrating injury
5) Spread from mediastinum e.g. oesophageal rupture.
6) Across the diaphragm.
Neutrophils in pleural fluid suggest what condition?
Underlying pneumonia.
Frank pus in pleural fluid suggests what condition?
Empyema
What cells in pleural fluid can mimic malignancy?
Reactive mesothelial cells.
Eosinophils in pleural fluid suggest what condition?
Pneumothorax or haemothorax. Rarely, drug reactions, parasitic infection, pulmonary infection, or Churg-Strauss syndrome.
Lymphocytes in pleural fluid suggest what condition?
Inflammatory disease such as RA,
Infection, including mycobacterial,
Malignancy,
previous CABG.
Usual imaging on presentation of mesothelioma.
Nodular or extensive pleural thickening, large unilateral pleural effusion, contraction of affected hemithorax,
invasion of surrounding structures,
focal pleural plaques.
CT features of an empyema
Lenticular shape Uniform enhancing wall Compression of adjacent lung Obtuse angle with chest wall ‘Split pleura’-separation of pleural layers May have air fluid level
Pleural tumours other than malignant mesothelioma
Mesenchymal including sarcoma
Lymphoma
Usual presentation of mesothelioma
Chest pain and dyspnoea
Bloody pleural effusion
Progress of malignant mesothelioma.
May be locally invasive (similar to lung
cancer)
Nodules –> plaques –> encase lung
Metastasises to nodes and distant sites late
Tissue diagnosis of mesothelioma requires…
Targeted needle biopsy or thoracoscopic biopsy
May need repeated attempt to get confirmation
Histological types of mesothelioma
Epithelioid
Sarcomatoid
Biphasic
Desmoplastic
Prognosis of mesothelioma.
94% die within 2 years of onset of symptoms
Median survival 10 months
Prognosis for epithelioid subtype slightly
better than for sarcomatoid or biphasic types
Benign lung tumours
Hamartoma.
Definition of hamartoma.
A tumour formed of mature
but disorganised elements normally found at
that site.
Key points about a hamartoma.
Circumscribed peripheral ‘coin’ lesion Symptomless, incidental Composed of cartilage, epithelium and connective tissue No malignant potential
Factors predisposing to lung cancer.
SMOKING!!! Urban living Asbestos Radon gas Radiotherapy
Basic division of lung cancers
Non-small cell
Endocrine
Rarities
Types of non-small cell lung cancer.
Adenocarcinoma (common in non-smokers)
Squamous cell carcinoma (nearly half all lung cancers),
Large cell undifferentiated
Types of lung endocrine tumour
Small cell (metastasises early). Large cell neuroendocrine Carcinoid (typical and atypical, NOT related to smoking.)
What age do people present with carcinoid lung cancers? Which type has a better prognosis.
Mean of 50 yrs.
Typical.
Is carcinoid lung cancer common?
No, it makes up less than 1% of lung cancers.
Complications of carcinoid lung cancers.
Bronchial obstruction inc distal collapse, bronchiectasis or pneumonia.
Haemoptysis
Key points about small cell lung cancer (endocrine)
Approx 16% of lung cancer
Metastasises early
Mediastinal lymph nodes often larger than
primary lung tumour
Prognosis for small cell lung cancer (endocrine)
Chemotherapy is the main treatment Only rarely operable Prognosis is poor Approx 3 months untreated 1-2 years with chemo
Key points of squamous cell carcinoma (non-small cell)
40-50% lung cancer and falling Arises on a main or segmental bronchus May cavitate Often directly invades hilar lymph nodes but metastasises late
Precursor lesion for squamous cell carcinoma.
squamous metaplasia
squamous dysplasia
carcinoma in situ
Key points for adenocarcinoma
20-30% of lung cancer and rising proportion Female predilection Lung cancer in non-smokers often adenocarcinoma May be central or peripheral
Precursor lesions for adenocarcinomas
Atypical adenomatous hyperplasia
Adenocarcinoma in situ (‘lepidic’)
Key points of large cell carcinoma
Crosses the non-small cell/endocrine divide.
10-20% lung cancer
No evidence of squamous or glandular
differentiation
Variety of subgroups
Large cell neuroendocrine carcinoma best known
Usually aggressive tumours
Spread of lung cancer: local, lymph and distant
Local: any local structure - if symp chain involved, Pancoast’s. Can also spread to recurrent laryngeal nerve or phrenic nerve.
Lymph: Hilum of lung then mediastinal and supraclavicular. Later, neck and abdominal nodes.
Distant: liver, brain, adrenal, bone, kidney, contralateral lung.
Staging of tumours
T = how big, how much invaded, how far from carina? N = lymphnodes, ipsi or contra. M = contralateral lung, malignant pleural effusion, distant.
