Asthma

Question 1

what is asthma characterised by

Answer 1

dyspnoea, cough and wheeze caused by REVERSIBLE airway obstruction

Question 2

what factors contribute to airway narrowing

Answer 2

bronchial muscle contraction, mucosal swelling/inflammation, increased mucus production

Question 3

symptoms of asthma

Answer 3

intermittent dyspnoea, wheeze, cough (often nocturnal), sputum

Question 4

precipitants of symptoms in asthma

Answer 4

cold air, exercise, emotion, allergens, infection, smoking, NSAIDS, B blockers

Question 5

what is the variation in asthma

Answer 5

diurnal variation in symptoms and peak flow. morning dipping of peak flow

Question 6

questions to ask when assessing asthma

Answer 6

exercise tolerance, sleep disturbance, acid reflux- 40-60% of those with asthma have reflux; other atopic disease; home- pets, feather pillows etc.

Question 7

signs asthma

Answer 7

tachypnoea, audible wheeze, hyperinflated chest, hyperresonant percussion, decr air entry,

Question 8

signs in severe attack

Answer 8

can’t complete sentences, pulse >110bpm, resp rate >25/min, PEF 33-50%

Question 9

signs in life threatening attack

Answer 9

silent chest, confusion, exhaustion, cyanosis, bradycardia, PEF <33%

Question 10

when does PaCO2 rise

Answer 10

near fatal attack. signifies failing respiratory effort

Question 11

tests in acute asthma

Answer 11

PEF, sputum culture, FBC, U and E, CRP, blood culture. ABG- normal or slightly low PaO2 but decr PaCO2 (hyperventilation)

Question 12

tests in chronic asthma

Answer 12

PEF monitor, spirometry. CXR- hyperinflation; skin prick tests could help identify allergen. histamine or methacholine challenge. aspergillus serology

Question 13

differential diagnosis asthma

Answer 13

pulmonary edema, COPD, large airway obstruction, SVC obstruction, pneumothorax, PE, bronchiectasis, obliterative bronchiolitis

Question 14

associated diseases with asthma

Answer 14

acid reflux, polyarteritis nodosa, Churg Strauss syndrome

Question 15

what are the steps in the management of chronic asthma

Answer 15

1- occasional SABA. 2- inhaled steroid (beclametasone). 3- LABA (salmeterol). 4- modified release B agonist. 5- regular oral prednisolone, high dose inhaled steroids

Question 16

how do B agonists work

Answer 16

relax bronchial smooth muscle acts within minutes. salbutamol- inhalation (also PO, IV).

Question 17

side effects B agonists

Answer 17

tachyarrhythmias, decr K, tremor, anxiety.

Question 18

example of long acting B agonist and when can these be useful. side effects

Answer 18

salmeterol, formoterol. nocturnal symptoms, reduce morning dips. SE- same as salbutamol, paradoxical bronchospasm

Question 19

what is the function of corticosteroids

Answer 19

act over days to decrease bronchial mucosal inflammation. inhaled to reduce systemic effects

Question 20

how are oral steroids given

Answer 20

acutely- high dose short course eg prednisolone, and longer term lower dose.

Question 21

MOA aminophylline

Answer 21

inhibits phosphodiesterase so decreasing bronchioconstriction by increasing cAMP levels.

Question 22

what is the problem with aminophylline, and side effects

Answer 22

narrow therapeutic index. arrhythmias, GI upset, fits

Question 23

anticholinergics used in asthma, MOA

Answer 23

decr muscle spasm synergistically with B agonists. ipratropium, tiotropium

Question 24

other drugs used in the management of asthma

Answer 24

cromoglicate, leukotriene receptor antagonists (montelukast), anti-IgE monoclonal antibody (omalizumab)

Question 25

presentation acute severe asthma

Answer 25

acute breathlessness, wheeze

Question 26

differential diagnosis asthma attack

Answer 26

exacerbation COPD, pulm oedema, pulm embolus, anaphylaxis, URT infection

Question 27

immediate treatment in asthma attack

Answer 27

salbutamol nebulised with O2. hydrocortisone IV or prednisolone PO. start O2 if saturations <92%