• Low flow O2

• Will not interfere with eating, drinking or communication.

• Rate 1-4L O2/ minute

• Delivers fio2 between 24-34%, depending on flow rate of oxygen, respiratory rate and depth of breathing

• Flow rates greater than 4L cause considerable drying of the mucosa and are more difficult to tolerate

Venturi masks are colour coded to denote a fixed FiO2, provided the minimum litres of oxygen on the barrel of the device is given. For example, a red venturi needs a minimum of 10 litres of oxygen to give 40% FiO2. To change the FiO2 you need to change the valve colour and adjust the oxygen. Venturi masks are fixed performance systems, which means the fio2 remains constant and is not effected by respiratory rate and depth of breathing.

• Blue – 24% with 2L O2

• White – 28% with 4L O2

• Yellow – 35% with 8L O2

• Red – 40% with 10L O2

• Green – 60% with 15L O2

This is a variable rate oxygen delivery system, capable of delivering 28% FiO2 up to 98% FiO2. It is better used for patients who will have oxygen requirements > 28% FiO2 for more than 24 hours. As with venturi masks, the delivered FiO2 is dependent on the accurate adjustment of the oxygen l/min as dictated by the blue dial.

Used for short term O2 delivery in critically unwell patients.

Requires a minimum flow of 10-15L of oxygen to deliver 60-85% FiO2.

The reservoir must be filled with oxygen prior to and during its use – hold the green one way valve closed to inflate it before administering to the patient. Whilst in use, the one way valve prevents exhaled air entering the bag and diluting the concentration of oxygen.

Once patients are stabilised, they should be changed to a more suitable method of oxygen delivery such as a humidified circuit. With fiO2 titrated to their target saturations.

HFNO delivers an air/ oxygen blend that can be titrated from 21% -100% FiO2. The inspiratory air/02 mix ranges from 30-60L flow of gas, which can provide a low level of positive end expiration pressure (PEEP). It is heated and humidified and reduces the risk of damage to the nasal mucosa whilst improving mucocilliary clearance.

It has a wide scope of use outside of critical care in the management of type 1 respiratory failure, including pneumonia and post operative atelectasis.

It is well tolerated by patients, easy to apply and is less restrictive to speech and eating/ drinking than oxygen masks.

Risks:

• Confused patients may remove HFNO

• If HFNO treatment fails, it could delay ICU admission

• Facial pressure sore risk

• Cannot be used for transfer – no battery pack

• Aerosol generating procedure (AEG), follow local infection control guidelines and use appropriate PPE

Contraindications:

• Base of skull fracture, epistaxis, recent nasopharyngeal surgery/ facial trauma

CPAP is a mode of respiratory support that uses a tight fitting mask to deliver a set level of PEEP (positive end expiration pressure). PEEP opens up the aveoli and promotes oxygen uptake. It provides the same amount of pressure (PEEP) throughout the inspiration and expiration cycle, which helps keep alveoli open at the end of expiration. It does not provide ventilation, but splints the airways open. It can help improve oxygenation and work of breathing. The FiO2 can be adjusted to the patient’s needs, from 21-100% FiO2.

It is used for type 1 respiratory failure most often due to pulmonary oedema, pneumonia and PE.

Please refer to NIV section for contraindications and management.

NIV (also commonly referred to as BiPAP), is form of non-invasive ventilation. Like CPAP it also provides continuous PEEP (EPAP setting) to keep the alveoli open and improve oxygenation. But it also provides ventilation, by giving additional pressure (IPAP) on inspiration, above the set level of EPAP. This assists with ventilation and helps with the removal of carbon dioxide. NIV is usually triggered by the patient taking their own breath but can be set to deliver breaths if the patient does not take one. It can be provided with and without oxygen, depending on the patient’s requirements.

It is used for type 2 respiratory failure most often due to COPD and diseases that cause respiratory muscles weakness such as motor neuron disease.

Abbreviations:

• PEEP – positive end expiration pressure

• EPAP – Expiration positive airway pressure

• IPAP – Inspiration positive airway pressure

For both CPAP and NIV:

Patient’s started on acute CPAP or NIV need close monitoring and hence this therapy is only provided on the ICU, some HDU’s and some respiratory wards. Staff in these areas have additional training to manage these patients. Outside these areas it can only be provided with support from the critical care outreach team.

Contraindications:

• Pneumothorax

• Low GCS

• Inability to clear secretions

• Patient vomiting

• Orofacial abnormalities

• Recent facial, GI or upper airway surgery

• Bowel obstruction

• Psychological

Before starting CPAP or NIV:

• Ensure patient monitored in an HDU setting on a cardiac monitor

• Consider insertion of an NG tube to decompress the stomach

• Consider inserting an arterial line for frequent ABG monitoring