Airway Equipment

Question 1

What is a nasal cannula?

Answer 1

Used for mild hypoxia and in non-acute situations

Delivers 24-30% O2 (maximum flow rate of 4L/min)

Tubing is placed around patient’s face with prongs positioned at nostrils

Tubing can be secured behind the patient’s head or around their ears

Caution(s)

– high flows will dry and irritate nasal passages

– does not allow close control of FiO2

Question 2

What is a Hudson Mask?

Answer 2

Used in mild hypoxia and non-acute situations

Delivers 30-40% O2 (flow rate 5-10L/min)

Mask is positioned over the patient’s nose and mouth with the elastic strap behind their head

Caution – does not allow close control of FiO2

Question 3

What is a reservoir mask?

Answer 3

Used for acutely unwell patients

Aims to provide high FiO2 concentrations as the oxygen is inhaled from the reservoir alongside the oxygen source

Delivers approximately 70% O2 when used with a 15L flow rate

Mask fits over the patient’s nose and mouth and can be secured to the face using elastic straps

Ensure the reservoir bag has filled by temporarily obstructing the valve before positioning on the patient

Caution – the mask is not tightly sealed so some entraining of surrounding air is unavoidable. It is therefore not a true fixed performance device.

Question 4

What is a venturi mask?

Answer 4

Designed to deliver constant FiO2 regardless of patient’s respiratory rate and flow pattern

Often used in patients with chronic obstructive pulmonary disease (COPD)

Fits over the patient’s nose and mouth like a Hudson mask

Details of required flow rate and percentage oxygen delivery are detailed on the coloured fittings:

Flow rate required–> (L/min)/FiO2 delivered:

• Blue –> (2-4)/24%
• White–> (4-6)/28%
• Yellow–>(8-10)/35%
• Red–> (10-12)/40%
• Green–> (12-15)/60%

Question 5

What is humidified oxygen?

Answer 5

• Standard oxygen gases have a drying effect on the mucous membranes that can result in airway damage, heat and fluid loss. Humidified oxygen reduces this effect and can assist in breaking down a patient’s respiratory secretions, making them easier to clear.
• Most effective when the gas reaching the alveoli is at body temperature (37ºC) with a relative humidity of 100%
• Oxygen is passed through a humidifying device producing sterile vapour before travelling in “Elephant” tubing to a face mask covering the patient’s nose and mouth
• Caution – water can pool in oxygen tubing. This needs to be drained regularly.