Respiratory Flashcards
What gender is idiopathic pulmonary fibrosis more common in?
Men (twice as likely).
What are the criteria for LTOT in COPD patients?
< 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
ABGs results are based on 2 results, 3 week apart
What must be done before offering azithromycin in patients with COPD.
Only offered if having frequent exacerbations despite optimum therapy in patients who DO NOT SMOKE.
Should have CT to exclude bronchietasis.
Sputum cultures for TB and atypical infections e.g. mycoplasma.
LFTs and ECG (prolongs QTc)
What are the features of cor pulmonale?
Features include peripheral oedema, raised jugular venous pressure, systolic parasternal heave, loud P2.
What is the treatment of cor pulmonale?
Loop diuretics +/- LTOT
ACE-inhibitors, calcium channel blockers and alpha blockers are not recommended.
What things improve survival in COPD
smoking cessation - the single most important intervention in patients who are still smoking
long term oxygen therapy in patients who fit criteria
lung volume reduction surgery in selected patients
What happens in ARDS?
Acute respiratory distress syndrome (ARDS) is caused by the increased permeability of alveolar capillaries leading to fluid accumulation in the alveoli, i.e. non-cardiogenic pulmonary oedema.
What are the causes of ARDS?
infection: sepsis, pneumonia massive blood transfusion trauma smoke inhalation acute pancreatitis cardio-pulmonary bypass
What are the criteria for ARDS?
acute onset (within 1 week of a known risk factor)
pulmonary oedema: bilateral infiltrates on chest x-ray (‘not fully explained by effusions, lobar/lung collapse or nodules)
non-cardiogenic (pulmonary artery wedge pressure needed if doubt)
pO2/FiO2 < 40kPa (200 mmHg)
What is the main role of alpha 1 antitrypsan
it is a protease inhibitor
Where is A1AT produced?
liver
What gene is A1AT deficiency located on
chromosome 14
What type of inheritance is A1AT deficiency
autosomal recessive
Outline the genotypes in alpha1 antitrypsan deficiecny
Normal = PiMM
PiSS (50 percent normal levels)
PiZZ (10 percent normal levels)
Patients who manifest the disease phenotypicall usually have PiZZ genotype
What does A1AT defiency result in
Emphysema
Liver cirrhosis
Hepatocellular carcinoma
What type of lung cancer is most commonly associated with cavitating lesions?
Squamous
What is the treatment of OSA
Weight loss
First line in moderate/severe is CPAP overnight
Intra oral devices can be uses if CPAP is not tolerated or in very mild cases
Outline the management of a primary pneumothorax
f 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 (defined as > 2 cm or still short of breath) then a chest drain should be inserted
Outline the management of a secondary pneumothorax
if the patient is > 50 years old and the rim of air is > 2cm and/or the patient is short of breath then a chest drain should be inserted.
otherwise aspiration should be attempted if the rim of air is between 1-2cm. If aspiration fails (i.e. pneumothorax is still greater then 1cm) a chest drain should be inserted. All patients should be admitted for at least 24 hours
if the pneumothorax is less the 1cm then the BTS guidelines suggest giving oxygen and admitting for 24 hours
What is the mechanism of varenicline?
Used to help smoking cessation.
Nicotinic receptor partial agonist.
How does sarcoidosis cause hypercalcaemia
Sarcoidosis mainly causes hypercalcaemia through forming increased concentrations of calcitriol, the active component of vitamin D. This is as a result of increased activity of 1α hydroxylase produced by the sarcoid macrophages.
What is sarcoidosis
multisystem disorder of unknown aetiology characterised by non-caseating granulomas. It is more common in young adults and in people of African descent
Name some characteristic features of sarcoidosis
acute: erythema nodosum, bilateral hilar lymphadenopathy, swinging fever, polyarthralgia
insidious: dyspnoea, non-productive cough, malaise, weight loss
skin: lupus pernio
hypercalcaemia: macrophages inside the granulomas cause an increased conversion of vitamin D to its active form
What is Lofgrens syndrome
acute form of sarcoidosis characterised by bilateral hilar lymphadenopathy (BHL), erythema nodosum, fever and polyarthralgia. It usually carries an excellent prognosis
