Flashcards in RESPIRATION GONE WRONG Deck (18)
what is type 1 respiratory failure?
PaO2 < 8kPa
PaCO2 < 6kPa
what are the causes if type 1 respiratory failure?
what is type 2 respiratory failure?
hypoxaemia and hypercapnia
PaO2 < 8kPa
PaCO2 > 6kPa
what are the causes of type 2 respiratory failure?
loss of respiratory drive
why should you not give high flow O2 to COPD patients (with type 2 respiratory failure)?
- central chemoreceptors will have reset to accommodate increased paCO2
- the oxygen will then cause further reduction in ventilation as peripheral chemoreceptors are inhibited by the increased O2 - this leads to death from acidosis by hypercapnia
what is hypoxic hypoxia?
low arterial O2 tension in blood
what is anaemic hypoxia?
not enough Hb to carry O2
what is stagnant hypoxia?
blood flow to the tissue is too slow
what is histotoxic hypoxia?
toxic agent prevents cells from using O2
what is A1-1 antitrypsin deficiency?
autosomal recessive mutation to SERPINEA1 gene on chromosome 14 - codes for serum antiprotease to inhibit neutrophil elastases
effects 1 in 10,000
what are the effects of A1-1 antitrypsin deficiency?
early onset emphysema and bronchiectasis
due to damage of elastin that maintains conducting airway structure
there is increased risk of de novo mutation with smoking
what is COPD?
polygenic disease with large environmental influence
it is the umbrella term for chronic bronchitis and emphysema
is an example of airways obstruction - reduced FEV1
what are the effects of emphysema?
it reduces surface area due to destruction and fusing of alveoli
capillaries are lost reducing gas exchange
lack of elastic recoil causes distended thorax
what is the effect of bronchitis?
it obstructs airways due to inflammation and increased mucus
how do you distinguish between asthma and COPD?
use spirometry with and without ventilin inhaler
- COPD is not reversible in the vast majority of cases
what is cystic fibrosis?
autosomal recessive mutation of CFTR
reduced Cl- and HCO3- apical transport - mucus becomes more viscous - leads to poor ventilation and recurrent infections
1 in 25 are carriers
1 in 2500 prevalence
how is cystic fibrosis detected?
through Guthrie heel prick test at birth