Respiratory Failure Flashcards
what are the types of resp failure
Type 1- low P02, normal pCO2
Type 2- low PO2, high pCO2
what happens with bad lungs and hypoxaemia?
hypoxaemia not corrected for (hypoventilation instead of hyper ventilation): low p02 and normal pCO2-> low pO2 and high pCO2.
High pCO2 leads to -> acidosis (H+ from CO2).
define hypoxaemia
low blood in arteries.
hypoxia= insufficient o2 to cells in body
what 3 main reasons to control oxygen therapy for hypoxaemic patients
1) can’t see changes in po2 if o2 sats are high.
2) people that are o2 sensitive- when pO2 rises the pCO2 rises. V/Q mismatching (co2 retention) can cause.
3) even without co2 retention, too much o2= not enough hb sites to bind co2= less blood buffering and lungs are bad so can’t correct.
difference in PO2 and O2 sats
o2 sats is % of hb binding sites occupied. Po2 is partial pressures. P02 is how much the o2 wants to diffuse into cells. Can have high SaO2 but low PaO2.
what is V/Q mismatching
in bad lungs/emphysema some alveoli get poor ventilation= vasoconstriction. Adding PaO2 to these alveoli= vasodilation but the ventilation is still poor (hypoventilation) so this just increases CO2 alveoli pick up which they can’t exhale= >arterial CO2.= CO2 retention.
can low Sao2s be okay?
Yes. In CO2 retention the o2 disassociation curve shifts to right. Many dundee people walking with Sao2 < 80%.
How is acidosis corrected for by body?
Renal HCO3 production to neutralise H+.
what to keep o2 sats at
88%-92%. do not start giving o2 above .
how to treat hypercarbia
control o2 sats + non invasive ventilation to remove co2.
types of hypoxia
circulatory, anaemic, toxic, hypoxaemic hypoxia.
is treating hypoxeamia treating SOB?
no
types of o2 masks
nasal cannula,
variable performance mask/ Hudson- 5-15l/min variable %o2s,
venturi masks,
non rebreathing mask highest %o2
