W20 - COPD Flashcards
what is COPD
COPD is the preferred term for patients who were previously diagnosed with chronic bronchitis or emphysema and in place of COLD and COAD
What does COPD stand for
Chronic
Obstructive - (Narrowing of airways)
Pulmonary - (Small airways or alveoli destruction)
Disease
what is COPD characterized by
airflow limitation that is not fully reversible
progressive abnormal inflammatory response of the lungs to noxious particles and gases
what is airflow limitation caused by
mixture of small airway disease and parenchymal destructions
Chronic bronchitis and emphysema
how potent is COPD
third leading cause of death worldwide
what are the risk factors of COPD
smoking environmental genetic factor occupational exposure frequent infections of the airways age >35 socio economical deprivation poor diet
what are the symptoms of COPD
progressive and exertional breathlessness (Dyspnea)
chronic cough
sputum production
wheezing and chest tightness
frequent winter bronchitis
upper respiratory infection
pulmonary hypertension
what are the symptoms of severe COPD
weight loss
anorexia
asymptomatic rib fractures
ankle swelling
depression
anxiety
what factors do we take into account when making a COPD diagnosis
AGE >35
RISK SMOKING
RESPIRATORY SYMPTOMS
TEST AIRFLOW OBSTRUCTION
AGE
RISK
RESPIRATORY
TEST
ARRT
what is bronchitis
inflammation of central airways and smaller airways
hypertrophy and hyperplasia occur to mucus secreting glands and smooth muscle in smaller airways (bronchioles)
These then become obstructed by intraluminal mucus, mucosal oedema and airways wall fibrosis
The obstruction and the mucus increase resistance to airflow and chronic viral and bacterial colonisation in the retained mucus
what is emphysema
persistent inflammation destroys alveoli at the end of small airways.
permanent enlargement of airspaces distal to the terminal bronchiole
accompanied by destruction of their walls
destruction of the parenchyma decrease the area for gas exchange + lung elasticity
hypertrophy of capillaries reduces ability to absorb oxygen and may increase blood pressure
what are the3 stages of pathogenesis of COPD
inflammatory cells and mediators - chronic inflammation
oxidative stress, reactive oxygen and nitrogen species
protease antiprotease imbalance
what are cytokines
redundant secreted proteins with growth, differentiation and activation functions which regulate the nature of immune responses and control immune cell trafficking and the cellular arrangement of immune organs
what are the aims to manage stable COPD
prevent and control symptoms
reduce the frequency and severity of exarcerbations
improve general health status and exercise tolerance
what non pharmacological management should be given
offer treatment and support to stop smoking
offer pneumococcal and influenza vaccinations
offer pulmonary rehab if indicated
co develop a personalised self management plan
optimise treatment for comorbidities
when should inhaled therapies be given
all the above interventions have been offered (if appropriate)
people have been trained to use inhalers and can demonstrate satisfacotry technique
what are inhaled therapies used for
to relieve breathlessness and exercise limitation
what does SABA stand for
short acting beta agonist
what does SAMA stand for
short acting muscarinic agonist
describe the mechanism of action for a short acting beta agonist
upon activation the beta agonist bind to the beta agonist active site, activating adenyl cyclase through G(alpha)s leading to an increase in cAMP levels.
The surge in cAMP activates PKA which phosphorylates myosin light chain kinase to inhibit contraction
PKA also actives the K+ channel inducing membrane hyperpolarization
this countaracts electrical excitation leading to contraction
cAMP inhibits Ca2+ release from intracellular store
All of which aid relaxation of the airway smooth muscle
how do muscarinic 1 receptors help mediate bronchodilation
release of relaxing agent from the respiratory epithelia or pulmonary nerves
what do muscarinic 2 receptors do
found on post ganglionic cholinergic nerves and they provide negative feedback to reduce acetylcholine release
what do muscaric 3 receptors do
found on airway, smooth muscle cells and glads
they mediate bronchoconstriction and mucus secretions
what is the mechanism of action of anticholinergic drugs
block muscarinic acetylcholine receptors causing bronchodilation and reduce mucus secretion
when is the peak affect in SAMA
onset after 20 mins with peak effect with 30 to 60 minutes
what is the duration of SAMA
3 - 6 hours
what is the peak effect of long acting muscarinic drugs
onset of 30-40 mins
peak effect 3 - 4 hours
duration of LAMA
24 hour duration of action
what are the side effects of inhaled anticholinergics drug
Common: dry mouth; arrhythmias;cough;dizziness;headache;nausea
Uncommon: Constipation; dysphonia; glaucoma; palpitations; skin reactions; stomatitis; urinary disorders; vision blurred
what cautions do we have when taking inhaled anticholinergics
tiotropium: can cause arrythmia, heart failure or myocardial infarction
what other treatment options are available
oral corticosteroid
mucolytic drug therapy
long actin phosphodiesterase 4 inhibitor
when is mucolytic drug therapy considered
considered in patients with a chronic cough, productive of sputum
what is the treatment plan
non pharmacological
Saba or Sama
LABA + LAMA or LABA + ICS
LABA + LAMA + ICS
