Pharmacology 6 - Prescribing O2 Flashcards
What is FiO2?
The fraction of inspired O2
What is SaO2?
Percentage of oxygen saturation of arterial blood
What is a major problem (especially with trauma patients) of giving high flow oxygen when they have an SaO2 of 100%?
As you fully saturate all haemoglobin with oxygen, you cannot see a change in SaO2 despite there being a change in pO2
What is respiratory failure?
It is defined as a pO2 of less than 8.0kPa. It caused by inadequate gas exchange resulting in hypoxia.
What is hypoxia?
Deficiency of oxygen in the tissues
What is type 1 respiratory failure?What causes this?Examples?
A low pO2 (less than 8.0kPa) with normal or low PaCO2Caused primarily by ventilation/ perfusion mismatche.g. pneumonia, oedema, asthma, emphysema
What is type 2 respiratory failure?What causes this?Examples?
Hypoxia (PaO2 less than 8.0 kPa) and hypercapnia (PaCO2 greater than 6.0kPa)Caused by alveolar hypoventilation, with or without V/Q mismatche.g. asthma, COPD, reduced respiratory drive, neuromuscular disease, kyphoscoliosis, etc.
What is hypoxaemia?
An abnormally low level of oxygen in the blood
What is hypercapnia?
Hypercapnia refers to high pCO2(alveolar)
What is hypercarbia?
Hypercarbia refers to high pCO2(arterial)
Why should you be cautious when giving oxygen to patients with chronic type respiratory failure?
These patients can be in hypoxic drive and therefore are sensitive to high concentrations of inspired oxygen causing them to develop hypercarbia and become acidotic very quickly