Flashcards in Oxygen and Respiratory Failure Deck (25):
How can oxygen travel in the blood?
Bound to haemoglobin or dissolved in the plasma
The amount of gas dissolved in a liquid is proportional to what?
The pressure of the gas
What is SaO2?
Oxygen saturation of arterial blood
What is SpO2?
Oxygen saturation as measured by a pulse oximeter
What is PaO2?
The amount of oxygen dissolved in arterial blood plasma
The amount of oxygen dissolved in the blood is proportional to what?
The partial pressure of oxygen
What does not increase in proportion to the partial pressure of oxygen?
The amount of oxygen bound to haemoglobin
What is FiO2?
Fraction of inspired oxygen- the amount of oxygen a patient is taking in through different oxygen masks
What happens when patients with chronic respiratory failure are given high concentrations of oxygen?
They will develop hypercapnia and become acidotic quickly
What is type 1 respiratory failure?
Low oxygen, normal CO2
What is type 2 respiratory failure?
Low oxygen, high CO2
What signifies chronic respiratory failure?
Differences in bicarbonate value as this takes a few days to show
Why does CO2 retention occur?
Because of V/Q mismatching- perfusion will still be good but ventilation will be poor
What physiological term does CO2 retention work around?
The Haldane effect
What does chronic hypercapnia cause?
Desensitisation of CO2 chemoreceptors and oxygen chemoreceptors become more important
What is the desensitisation of CO2 chemoreceptors known as?
What can hypoxaemia lead to?
Altered mental state, cyanosis, dyspnoea, tachypnoea, arrhythmias
What is perfusion without ventilation known as?
What is ventilation without perfusion known as?
Which is more common, shunting or dead space?
Which diseases is dead space usually found in?
Pulmonary embolism, vasculitis and hypertension
How much oxygen should be given in medical emergencies?
As much as possible
What is the target SaO2 for patients with COPD/obesity/scoliosis/cystic fibrosis?
What should target saturations normally be?