Obstructive Lung disease Flashcards
(37 cards)
What is the ratio of FEV1:FVC supposed to be for a Lung disease to be classed as Obstructive
Less than 70%
Peak excitatory flow rate can be used to determine if obstructive lung disease is present, True/False?
True
What are the different classifications of PEFR in diagnosing obstructive lung disease?
Normal: 80-100% of best
moderate fall: 50-80% of best
Marked Fall:
What conditions does obstructive airway disease consist of?
Chronic bronchitis, emphysema and asthma
what conditions does COPD consist of?
Chronic bronchitis and emphysema
What causes bronchial asthma?
Type 1 hypersensitivity in airways. Mast cells degranulate and release chemotactic molecules and spasmogens, which cause constriction of the airway
What separates asthma from COPD?
Asthma airway obstruction is considered reversible (comes in attacks), and can either go away spontaneously or if treated with salbutamol
What is the aetiology of COPD?
Smoking, pollution, occupational hazards (dust), alpha-1-antiprotease deficiency (antitrypsin)
What is the clinical definition of chronic bronchitis?
A cough which is productive of sputum most days in at least 3 consecutive months for 2 or more years
What is the pathological definition of emphysema
an increase beyond the norm in the volume of aispaces distal to the terminal bronchiole arising either from dilatation or destruction of their walls without obvious fibrosis
what is an acinus?
the area where the terminal bronchiole is surrounded by alveoli
clinical definition of asthma?
widespread narrowing of airways that changes either spontaneously or as a result of therapy
what genetic factors contribute to development of asthma?
atopy
What are some occupations that carry an increased risk of developing asthma?
spray painters, welders, food workers, cleaners
what are some causes of wheezing illness by airflow obstruction?
inhaling a foreign body, inspiratory stridor, tumour
What are some symptoms of asthma?
wheeze, panting, dry, exertional cough
How would asthma be diagnosed?
Spirometry to check if obstruction is present, if so then full pulmonary function test takes place
What does doing a full pulmonary function test check for?
Checks the Lung volumes, which will show an increase of over 30 percent in the residual volume and total lung capacity by up to 30 percent due to gas trapping
how would you differentiate between asthma and another respiratory disease using a pulmonary function test?
check response to B2 agonist: 15 mins post 400 micrograms of inhaled salbutamol or 15 mins post 2.5-5mg nebulised salbutamol, if there is significant reversibility ; >200ml FEV1 and FEV1 >15% baseline
what would you do if an obstruction was still present after a B2 agonist had been administered?
Check the response of the airway to oral corticosteroids
what is the most potent asthma treatment and when would it be prescribed?
inhaled corticosteroids, if asthma is disrupting a patient’s sleep
if the airway is still obtructed after oral corticosteroids have been prescribed, what would you give the patient?
0.6mg/kg prednisolone for 14 days
If a patient’s lung function is normal in clinic but they are suspected of being asthmatic, what would you look for?
Variability in peak flow, which can be shown by getting the patient to use a peak flow meter twice a day for 2 weeks, you would expect to see morning/nocturnal dips and 20% variability in asthmatics
what other investigations could be used to try and diagnose asthma
Bronchial provocation - checking the responsiveness of airways to metacholine and histamine and possibly nitrous oxide, which are smooth muscle dilators, skin prick testing for atopy
