High flow oxygen therapy (HFOT)

High flow oxygen therapy is a form of respiratory support used in the hospital where oxygen, often in conjunction with compressed air and humidification, is delivered to a patient at rates of flow higher than that delivered traditionally in oxygen therapy.

Traditional oxygen therapy is up to 16 L/min and high flow oxygen therapy is up to 60 L/min.1

High flow oxygen therapy is usually delivered using a blender connected to a wall outlet, a humidifier, heated tubing and nasal cannula.  

High flow oxygen therapy reduces the work of breathing2

This warm, humidified constant flow improves gas exchange and reduces work of breathing. 3

High flow oxygen therapy in acute respiratory failure

High flow oxygen therapy is commonly used on patients with acute respiratory failure (ie, hypoxemic respiratory failure) in the hospital system. Patients are usually in ICU or high dependency wards, and require assistance with respiration to stabilise breathing and control blood gases.

High flow oxygen therapy in chronic conditions

Humidified high flow oxygen therapy has been used successfully in COPD, bronchiectasis, end-stage cancer and do-not-intubate patients.3

High flow oxygen therapy is intended to: 2

  • Eliminate most of the anatomic dead space
  • Create a reservoir with high FiO2 in the nasal cavity
  • Improve gas exchange
  • Significantly reduce the work of breathing

Other positive effects of high flow oxygen therapy (with humidification): 2

  • Using humidified (warmed) gas keeps mucus more fluid and aids airway recovery (eg, after surgery)
  • Reduced respiratory rate
  • Less dyspnoea (laboured breathing or shortness of breath / breathlessness) and mouth dryness, and greater overall comfort
  • Ease of set-up – easier to fit a nasal cannula than an oxygen mask
  • Low level of patient compliance needed (sedation possible but not required)
  • Patients say it is very comfortable and allows them to communicate

ResMed’s AcuCare™ High Flow Nasal Cannula

The AcuCare High Flow Nasal Cannula provides high flow oxygen therapy for adult patients with acute respiratory failure. It is designed to deliver continuous oxygen therapy up to a maximum flow of 60 L/min.

The AcuCare High Flow Nasal Cannula is for single-patient use (maximum seven days) in the hospital/clinical environment. It has been designed to provide superior comfort and ease of use to patients requiring high flow oxygen therapy.



Lindenauer PK et al. Outcomes associated with invasive and noninvasive ventilation among patients hospitalized with exacerbations of chronic obstructive pulmonary disease. JAMA Intern Med. Dec 1, 2014;174(12):1982–93.


Dysart K et al. Research in high flow therapy: mechanisms of action. Respir Med. 2009 Oct;103(10):1400-5.


Gotera C et al. Clinical evidence on high flow oxygen therapy and active humidification in adults. Rev Port Pneumol. 2013; 19(5):217–227.