Respiratory Flashcards
What do you request to be checked in the pleural fluid when sending it away?
pH, protein, lactate dehydrogenase, cytology and microbiology
When do you use Light’s criteria?
This is used when deciding if a pleural effusion has a transudate or exudate cause. Light’s criteria should be applied if the protein level is between 25 and 30.
What are the differences in protein levels between transudate and exudates?
exudates have a protein level of >30 g/L, transudates have a protein level of <30 g/L
Using lights criteria, what defines an exudate?
An exudate is likely if at least one of the following apply;
pleural fluid protein divided by serum protein >0.5
pleural fluid LDH divided by serum LDH >0.6
pleural fluid LDH more than two-thirds the upper limits of normal serum LDH
What might a low glucose in the pleural fluid indicate?
Rheumatoid or TB
What might a raised amylase in the pleural fluid indicate?
Pancreatitis or oesophageal perforation
What would heavily blood stained pleural fluid indicate?
Mesothelioma, TB, Pulmomary embolism
What tests should patients with suspected asthma have?
Fractional exhaled nitrous oxide test and a spirometry with reversibility.
Why do ?asthmatics have a FeNO test?
Nitric oxide is produced by 3 types of nitric oxide synthases (NOS). One of the types is inducible (iNOS) and levels tend to rise in inflammatory cells, particularly eosinophils. Levels of NO therefore typically correlate with levels of inflammation.
Reversibility testing in asthmatics
in adults, a positive test is indicated by an improvement in FEV1 of 12% or more and increase in volume of 200 ml or more
in children, a positive test is indicated by an improvement in FEV1 of 12% or more
What are the common causes of respiratory alkalosis?
Anxiety leading to hyperventilation Pulmonary embolism Salicylate poisoning CNS poisoning CNS disorders (stroke, SAH, encephalitis)
What are the criteria for LTOT?
Offer LTOT to patients with a pO2 of < 7.3 kPa or to those with a pO2 of 7.3 - 8 kPa and one of the following: secondary polycythaemia nocturnal hypoxaemia peripheral oedema pulmonary hypertension
What is a ghon focus?
Small lung lesion, tubercle laden macrophages. This indicates a primary infection with TB
When can the ghon complex develop?
In non-immunocompromised patients, this usually scars over and heals with fibrosis.
In immunocompromised patients, they may develop disseminated disease (miliary TB).
What is Pott’s disease?
It is a form of TB which occurs outside the lung in the vertebral bodies
How do you manage a primary pneumothorax of 2 cm or less?
if the rim of air is < 2cm and the patient is not short of breath then discharge should be considered
otherwise aspiration should be attempted.
If this fails (more than 2cm) insert a chest drain!
How do you manage a secondary pneumothorax of 2cm or less?
Aspiration should be attempted. If this fails (more then 1cm still) patient should be admitted and a chest drain inserted.
A secondary pneumothorax in a >50 patient which is 2cm and/or patient is short of breath, how do you manage?
Insert a chest drain
Clinical features of klebsiella infection?
(Most common in alcoholics).
-currant jelly-like sputum.
They are implicated in many other disorders such as ascending cholangitis. Following pneumonia, patients can develop an empyema. This translates to a ‘bag of pus’. It should not be confused with an abscess as an abscess is a collection of pus inside a newly formed cavity. An empyema is a collection of pus in an already existing cavity such as the pleural space.
What are the common causes of bilateral hilar lymphadenopathy?
Sarcoidosis and TB/ lymphoma
Which condition is associated with high levels of serum ACE?
Sarcoidosis
Why do you see hypercalcaemia in sarcoidosis?
macrophages inside the granulomas cause an increased conversion of vitamin D to its active form (1,25-dihydroxycholecalciferol)
Clinical features of bronchiectasis?
Affected patients may produce large amounts of purulent sputum
Patients may have a history of previous infections (e.g. Tuberculosis, measles), bronchial obstruction or ciliary dyskinetic syndromes e.g. Kartagener’s syndrome
Anaemia
What is wegners granulomatosis?
It is an autoimmune condition associated with a necrotizing granulomatous vasculitis, affecting both the upper and lower respiratory tract as well as the kidneys.
ANCA positive in >90%
NICE guidelines for low-severity and moderate/severe CAP?
Low- penicillin
High (DUAL ANTIBITOTIC)-penicillin + macrolide
NICE recommend considering a beta-lactamase stable penicillin such as co-amoxiclav, ceftriaxone or piperacillin with tazobactam and a macrolide in high-severity community acquired pneumonia
What is Primary ciliary dyskinesia?
dextrocardia or complete situs inversus
bronchiectasis
recurrent sinusitis
subfertility (secondary to diminished sperm motility and defective ciliary action in the fallopian tubes)
What condition is tram-track opacities seen on X-ray?
Bronchiectasis
What range of pH is most likely to respond to NIV?
7.25-7.35
What are the criteria for using NIV?
COPD with respiratory acidosis pH 7.25-7.35*
type II respiratory failure secondary to chest wall deformity, neuromuscular disease or obstructive sleep apnoea
cardiogenic pulmonary oedema unresponsive to CPAP
weaning from tracheal intubation
What is the difference in the FEV1/FEC values in an obstructive and restrictive picture?
Obstructive- FEV1 is significantly reduced and the FVC can be normal or reduced (think x-ray picture) with the overall ratio being reduced.
Restrictive- FEV1 is reduced and the FVC is significantly reduced leaving the overall ratio to be normal or increased.
