WEEK 11 Flashcards
What is allergic asthma?
Recurrent reversible airway obstruction with attacks of wheezing, shortness of breath & often a nocturnal dry cough
- airway inflammation, bronchial hyper-resposiveness
What is the pathogenesis of asthma?
activation of Th2 profile of cytokine production in genetically susceptible people
- it attracts eosinophils to mucosal surface
- IL-5 & GMCSF cause eosinophils to produce cysteinyl leukotrienes & release granule proteins
- IgE synthesis promoted & expression of IgE receptors on mast cells & eosinophils
What are important mediators in asthma?
- leukotriene B4 and cysteinyl- leukotrienes IL-4, 5 and 13, and tissue damaging eosinophil proteins
What is used to monitor the treatment of asthma?
Peak expiratory flow rate
- also FEV, O2 sats and arterial blood gases
What are the 5 main classes of drugs used to treat asthma?
- Beta 2 adrenoreceptor agonists
- Anti - inflammatories
- Cysteinyl leukotriene antagonists (LTRA)
- Methylxanthines
- Anti-IgE treatment
Give examples of Beta 2 adrenoreceptor agonsts.
SABA e.g. salbutamol (lasts 3-5 hrs)
LABA e.g. salmeterol (lasts 8-12 hrs)
Give examples of inflammatory mediators. What is their action ?
GLUCOCORTICOIDS e.g. beclometasone, budesonide
- they prevent progression of chronic asthma
- decrease: formation of cytokines, generation of vasodilators and activation of eosinophils
- in deteriorating asthma, oral (prednisolone) or IV (hydrocortisone) can be given
Give an example of a cysteinyl leukotriene antagonist. What is its MoA?
Montelukast
- antagonises only CysLT1 which decreases exercise induced asthma and decreases early and late allergen responses, relaxes airways in mild asthma and decreases acute reactions to aspirin
- is used mainly as an add on to ICS and LABAs
What are methylxanthines? What are they used for?
Theophylline and its derivatives
- theophylline = increases cyclic nucleotides in cell to relax smooth muscle
- uniphyllin orally in addition to steroids for COPD
- rarely it is used IV aminophylline in acute severe asthma
Give an example of an anti-IgE treatment drug.
Omalizumab
What is the steps/process for treating acute severe asthma?
IMMEDIATE TREATMENT (adults)
- O2 (sats kept at 94-98%)
- salbutamol or terbutaline plus ipratropium via nebuliser
- IV hydrocortisone or prednisolone tablets
IF NO IMPROVEMENT IN PT
- IV magnesium sulphate
- switch from nebulised to IV salbutamol or aminophylline
MONITOR BLOOD GASES and PT EXHAUSTION/ALERTNESS
What is ipratropium? What is it used for?
SAMA used for some COPD patients, especially the long acting (LAMA) version - tiotropium
- rarely used in asthma
- used for cough caused by irritant stimuli
- decreases augmentation of mucus secretion and may increase bronchial secretion clearance
- not selective for one muscarinic type
- used for bronchospasm precipitated by beta blockers
- not effective against allergen challenge
What does PICO stand for?
Patient
Intervention
Comparison
Outcome
What is the 3 points for the ‘anatomy’ of a good question?
- Define who the q is about
- Define which option you’re considering (drug treatment) and a possible comparison (placebo or stnd therapy)
- Define desired (or undesired) outcome
What are the 3 types of information resources? (HINT: put in order of importance/priority)
- Systematic Reviews and Meta-analyses
- cochrane reviews, 2ndary sources of info - Clinical practice guidelines
- NICE and SIGN - Original article containing primary research data (RCT)
What is hypothesis construction? What is the difference between a null and alternative hypothesis?
Is one set of data different from another?
NULL = 2 sets of data from same population and NOT different
ALTERNATIVE = 2 sets of data from different population and are different
What are the 2 types of quantitative data? Describe them.
DISCRETE - can only have certain numerical values
CONTINUOUS - don’t have discrete steps
What are the categorical variables? Describe them.
NORMAL (unordered categories)
- male/female, green/blue eyes, alive/dead
ORDINAL (ordered categories)
- objective: heavy, moderate or light drinkers, grade of breast cancer
- subjective: health status questionnaires
What is hypothesis testing? What is the P value? What does a P of 0.1 mean? What value of P means a null hypothesis can be rejected?
Assume null hypothesis and determine the probability that the null hypothesis is correct: P value
P of 0.1 = 10% chance null hypothesis is correct
If P<0.05 then null hypothesis can be rejected as there’s a statistically significant difference
What is a (i) type I (ii) type II error?
(i) Rejecting null hypothesis when it is true (false +ve)
- concluding there’s an effect when there isn’t
(ii) NOT rejecting null when it’s false (false -ve)
- concluding there’s no effect when there is
What is the power of a test?
Its ability to reject a null hypothesis when it is false
- the capacity to detect an effect if one present
What is the pathogenesis of AMI?
Atherosclerotic plaque destabilisation
- rupture or erosion
- platelet adherence and aggregation
- intracoronary coagulation
What are the 4 complications of an acute myocardial infarction?
- ARRHYTHMIA
- bradycardia = heart block
- tachycardia = AF, VT, VF - MYOCARDIAL DEATH
- pericarditis, VSD, free wall rupture, papillary muscle necrosis - LV THROMBUS and EMBOLISATION
- HEART FAILURE
- pump failure
- LV dilatation
- LV aneurysm
How do you know if someone is dead?
- Cessation of the CIRCULATION
- no pulses
- no cardiac activity (no heart sounds or electrical activity) - Cessation of RESPIRATION
- Cessation of CEREBRAL function
- fixed dilated pupils (don’t constrict in response to a light stimulus)