Oxygen Flashcards
What is a type 1 respiratory failure
- this is when the partial pressure of oxygen in the blood is below 8kPa
what is type 2 respiratory failure
- this is when the partial pressure of carbon dioxide is >6.1kPa and the partial pressure of oxygen is less than 8 kPa
How must a simple face mask be used
= 5-10l/min
= delivered oxygen concentration of 40-60%
- not the best intimal oxygen delivery device
what should a nasal cannulae not be used above
- should not be used above 6l/min as there is a significant risk of drying out the airways
what are the advantages and disadvantages of a nasal cannulae
Advantage
- more comfortable
Disadvantage
- can cause nasal irritation
- cannot determine the actual FiO2 that is given to the patient
When are venturi masks used
- when there is a risk of hypercapnic respiratory failure
When is a high concentration reservoir mask used
- mainly used if a patient has a critical illness such as trauma or cardiac arrest
- flow rate is 15l/min
What is high flow humidified oxygen
- this system can deliver a flow rate between 2-60l/min and oxygen concentration between 21-100%
- has a small positive airway pressure effect to reduce the work of breathing
When is CPAP used
- CPAP is a type of ventilatory support
when should a repeat ABG be done if the patient is at risk of hypercapnia respiratory failure
- this must be done within 30-60 minutes of starting or any change in oxygen delivery
How does the high concentration reservoir bag work
- fills with oxygen from the wall when connected to the flow meter
- patient will be able to breathe in the oxygen contained within this bag
- face mask - connected to the reservoir bag via the connector
- the fitting of the mask can be adjusted by the nose clip and the adjustable straps
- there are two exhalation ports on each side where air leaves so it cannot be rebreathed
- connector stops this as it is a one way valve
what is the key thing you should do with the reservoir bag
- do not put the oxygen bag on the patient until the reservoir bag has been sufficiently inflated
- the oxygen the patient breathes in comes from the bag and it must be inflated first
What do oxygen saturations represent
- they represent how much of the saturated the haemoglobin within the body is with oxygen e.g. how much of the haemoglobin is bound with oxygen as a percentage
What are the two main ways to measure oxygen saturations
- pulse oximetery - SpO2
- ABG - SaO2
What is hypoxaemia
- this is when the partial pressure of oxygen in the blood is low