Oxygen and Respiratory Failure Flashcards
What is the difference between type 1 and type 2 respiratory failure?
Type 1 - Short of oxygen
Type 2 - Short of oxygen AND too much carbon dioxide.
What problem can type 1
respiratory failure lead to?
Type 2 respiratory failure
What is hypoxaemia?
Low oxygen in the blood
What is the pathway of primary hypoxaemia in good lungs?
The Tidal volume and respiratory rate increases.
Normal pO2 levels and low pCO2 levels (good)
What is the pathway of primary hypoxaemia in bad lungs?
Low O2 and normal pCO2 (type 1 respiratory failure)
This can then lead to Low pO2 and High pCO2 (type 2 respiratory failure)
What bad thing can happen after primary hypoxaemia with good lungs?
It change into type 1 respiratory failure
What does high C02 cause in the lungs?
Acidosis
How does the body reduce acidosis?
Liver increases HCO3 to balance out pH
After the liver fixes acidosis, how can this change?
There could be an infection in which causes CO2 to be very high and so causes acidosis again.
What is more important? lack of oxygen or too much carbon dioxide?
Lack of oxygen - worry about too much CO2 later
How common is type 2 respiratory failure?
Very common
What is wrong with doctors giving patients oxygen?
They are poisoning them as the oxygen does more harm than good in certain situations.
Why is giving patients maximum oxygen bad?
This is because a patient’s oxygen saturation can can still show 100% even if their lungs have become damaged (low oxygen) - can’t see when patient is getting worse.
Why must oxygen be prescribed?
It counts as a drug and a patient will not get it if not prescribed
What is the first rule when prescribing oxygen?
Only give oxygen if the risk/benefit ratio is in the favor of oxygen.
What’s the problem with people who are sensitive to oxygen?
The CO2 levels can rise significantly when their O2 is increased. This can cause acidosis and life threatening.
What is the frequency of COPD patients retaining CO2 and are oxygen sensitive?
1 in 5
What are examples of diseases that can cause type 2 respiration?
Cystic fibrosis, kyphoscoliosis and morbid obesity.
What is V/Q mismatching?
This is when a patient has emohysema/COPD/Chronic lung disease and it leads to poor ventilation. This causes hypoxic vasoconstriction (V) and poor perfusion (Q) so V=Q. When there is oxygen it makes the perfusion good but ventilation still bad and so Q doesn’t equal V! this means alveolar pCO2 increases and it can’t be exhaled due to poor ventilation.
What is the haldane effect?
Oxygen can displace CO2 from haemoglobin
What is the Bohr effect?
High concentrations of CO2 prevent O2 binding to haemoglobin