COPD Flashcards
COPD definitions
A condition that makes it harder to breathe due to damage to airways and destruction of lung tissue (parenchyma)
- The collective (and preferred) term for patients with airflow obstruction and inflammation in the lungs, who were previously diagnosed with chronic bronchitis or emphysema
- A preventable condition, which is poorly reversible, and progressive in nature
how is COPD diagnosed
There is no single diagnostic test for COPD
• A clinical judgement, based on history, examination and confirmation of airflow obstruction using spirometry
what is GOLD 1
Mild
FEV1/FVC <0.70
FEV1 > 80% predicited
What is GOLD 2
Moderate
FEV1/FVC <0.70
80% > FEV1 > 50% predicited
what is GOLD 3
Severe
FEV1/FVC <0.70
50% > FEV1 > 30% predicited
What is GOLD 4
Very severe
FEV1/FVC <0.70
FEV1 < 30% predicited or FEV1 <50% predicited plus chronic repsiratory failure
COPD prevalence UK
- 1 million diagnosed with COPD
- Approximately 2 million undiagnosed cases
- 1 in 8 people over 35 y has undiagnosed COPD
comorbidities associated with COPD
CVD, chronic inflammation, CHF, muscle atrophy, osteoporosis, metabolic disease, depression
effect of tabacco on COPD
Tobacco attributable to:
• 73% of COPD mortality in high-income countries
• 40% of COPD mortality in low/middle-income countries
effect of pollution on COPD
Accounts for ~20% of COPD (rises to 31% in “never smokers”
Accounts for ~35% of COPD in low/middle income countries
effet of COPD on exercise
impaired ability ot empty lung during exercise (dynamic hyperinflation)
evidence of PA on COD
hosptial admission shorter
time to death longer
27% reduced risk of death for moderate PA
20-40% reduction of hosptial admission for PA
causes of muscle dysfunctin in COPD
malnutrition hypercapnia hypoxia medicatins disuse/Physical inactivity oxidative stress
objectives of pulmonary rehab
- To control, alleviate and, if possible, reverse the symptoms and pathophysiologic processes leading to respiratory impairment
- To improve quality of life, and attempt to prolong the patient’s life
essential components of pulmonary rehab
- Exercise training
- Education
- Psychosocial/behavioural interventions
- Outcome assessment
practical goals of pulmonary rehab
- Reduce the cost of breathing
- Improve pulmonary function
- Normalise arterial blood gases
- Alleviate dyspnoea
- Increase efficiency of submaximal exercise/tasks
- Improve exercise capacity and ability to perform daily activities
- Correct poor nutrition
- Restore a positive outlook/improve emotional state
- Decrease health-related costs
- Lengthen quality and quantity of life
what should the exercsie program be like
- Use dyspnoea scale first: level 2-3
- HR or VO2 can be used to set exercise intensity from a GXT Caution needed
- Try to exercise at > 50 % peak VO2 Caution and common sense needed
- Circuit based activities of 1-10 min
- Rest intervals allow a greater intensity to be tolerated
- Rest intervals allow for recovery of oxygen saturation
- Aim to accumulate 5-10 min on 3-5 days per week
- 4-12 weeks typically needed for any improvement
- Progression = increase work intervals, then decrease rest periods
effect after 1 month detraining
significant falls in performance
effect of smoking on chronic bronchitis
-reduced size of cila
-reduced cilla mortaility
-increase goblet cells = more mucus
-inflammation - increase endothelial space
-increase size and amount of submucus glands
= reduced size of airway
= more mucus with trapped pathogens and dust
effect of chronic bronchitis on the heart
increased pulmonary artery pressure
increased RV afterload
decreased LV afterload
increased cardiac output
body response to hypoxic tissue
when tissue becomes hypoxic, the blood vessels that perfuse that tissue will vasodilate
hypoxic pulmonary vasoconstriction
when tissue in lungs becomes hypoix - vasoconstriction
not efficient to sned blood to damaged aveolar so VC
effect of hypoxic pulmonary vasoconstriction on heart
increased pulmonary arterial pressure
right ventricle afterload increases
Emphysema and smoking
eleastin reponds to smoking
causes release of free radicals
macrophages release pro-inflammatory cytokies
- signal chemotaxis - neutrophils which release protease which break down the elastin and paracyimal tissue
causes endothelaila dysfunction
endothelial dysfunction in emphysema
cant vasodilate
hypoxic vasoconstriction
decreased perfusion
kidneys response to emphysema
release EPO
increase red blood cells - polycythemia
increases thickness of blood = more likely to clot
air trapping in emphysema
alveolar emptying time relies on expiratory time
insufficent during exercsie
already air in lungs from previous breath
decreased inspiration capacity
reduced breath depth
inpaired ability to empty lungs
worsen length-tension relationship of diaghragm and increases cost of breathing
effect of air trapping on VO2
40% of submax VO2 is due to the cost of breathing
10-15% nromally
what id dynamic hyperinflation
imapired ability to empty lung during exercise
effect of COPD on lung function
resting and dynamic increase end expiratory lung volume so tidal volume is shifted up the pressure-volume curve where there is an increased eleastic loading
= decreased inspiratory reserve volume
overall positive effects
increased lung capacity
increased residual volume
overall negative effects
decreased chest wall compliance increased inspiratty resistnce decreased peak flow rate decreased FVC decreased FEV1
areas for theraupetic targets
anxiety
deconditioning
activity limitation
exacerbatins - smoking
