Mechanisms of action

How does high flow therapy work?

Nasal high flow confers benefits that conventional therapies cannot

It's a significantly more sophisticated form of respiratory support, that includes the provision of dynamic, positive airway pressure, and reduction of dead space

The airway hydration resulting from heating and humidifying the air is critical to facilitating comfortable treatment but is equally valuable in preserving mucociliary function. This is why it's at the heart (or more accurately lungs) of this therapy. 

As with any treatment, patient comfort is a significant factor. One of the standout features of NHF is the level of respiratory support that can be achieved without the downsides of a mask.

Accelerate your understanding of the mechanisms of NHF 

If you want to be a high-flow pro, i.e., be able to identify which patients will benefit from high flow, knowing the mechanisms of action is the key!

Follow this plan to accelerate your knowledge.

How does nasal high flow work? Learn about the key mechanisms of action for NHF, driven by flow and humidification.
(2 mins) 

Mechanisms in action
Step through each mechanism (below) to see the science that underpins it - watch microscopic cilia beating, lungs expanding, dead space being cleared.


How does High Flow Therapy work? 

An F&P Micro Moment! 

This short video explains the key mechanisms of action of Nasal High Flow, driven by flow and humidification.
(2 mins)  

Click here to see the full series of Micro Moments. #makeyourflowmatter

Dead space reduction increases alveolar ventilation

Clearance of expired air in the upper airways reduces rebreathing of gas high in CO2 and depleted O2, increasing alveolar ventilation.

Dynamic, positive airway pressure increases alveolar ventilation

NHF creates breath and flow-dependent pressure, making inspiration easier and promoting slow, deep breathing on expiration, thereby increasing alveolar ventilation.

Airway hydration maintains mucociliary clearance

Humidity that is integral to Optiflow therapy enables the comfortable delivery of high flows of gas. Optimized humidity emulates the natural balance of heat and moisture in healthy lungs and may promote physiological stability in compromised airways.  

Patient comfort is improved with a cannula

Respiratory support delivered via a mask poses challenges for clinicians and patients. NHF delivered via a cannula promotes patient comfort and may improve compliance.

Supplemental oxygen (if required)

Oxygen delivered via conventional oxygen therapy (COT) is 'bone' dry. Delivering oxygen via NHF therapy allows for oxygen to be optimally humidified eliminating the issues associated with exposure of the vulnerable upper airway to dry gas. Additionally delivering oxygen via NHF gives you confidence in the accurate delivery of blended oxygen. 


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