From the Guidelines
Oxygen delivery systems for intensive care unit patients should prioritize high-flow nasal oxygen (HFNO) therapy for managing acute hypoxemic respiratory failure, as it offers improved patient comfort and physiologic advantages compared to conventional oxygen therapy and noninvasive ventilation, as suggested by the American College of Physicians guideline from 2021 1.
Overview of Oxygen Delivery Systems
Oxygen delivery systems for intensive care unit patients include several options based on the patient's needs and severity of respiratory compromise. These options can be categorized into low-flow, high-flow, and non-invasive ventilation systems.
- Low-flow systems:
- Nasal cannulas deliver 1-6 L/min of oxygen with FiO2 of 24-44%
- Simple face masks provide 5-10 L/min with FiO2 of 35-60%
- High-flow systems:
- Non-rebreather masks deliver 10-15 L/min with FiO2 up to 90%
- High-flow nasal cannula (HFNC) systems provide heated, humidified oxygen at rates of 30-60 L/min with precise FiO2 control
Recommendations for Oxygen Delivery
The use of HFNO is recommended over conventional oxygen therapy and noninvasive ventilation for hospitalized adults with acute hypoxemic respiratory failure, as it reduces the work of breathing and improves patient comfort, as stated in the guideline from the American College of Physicians 1.
- For patients requiring higher oxygen concentrations, non-rebreather masks or HFNC systems should be considered
- For patients with more severe respiratory failure, non-invasive ventilation options such as Continuous Positive Airway Pressure (CPAP) and Bilevel Positive Airway Pressure (BiPAP) may be necessary
Selection of Oxygen Delivery System
The selection of the appropriate oxygen delivery system depends on the patient's oxygenation needs, work of breathing, risk of respiratory failure, and underlying condition, with the goal of maintaining adequate tissue oxygenation while minimizing complications such as oxygen toxicity and ventilator-associated pneumonia, as discussed in the BTS guideline for oxygen use in adults in healthcare and emergency settings from 2017 1.
- The choice of oxygen delivery device should be based on the patient's individual needs and the availability of equipment
- The flow rate and FiO2 should be adjusted to achieve the desired target saturation, taking into account the patient's condition and response to treatment.
From the Research
Oxygen Delivery Systems for ICU Patients
- Oxygen therapy can be delivered using low-flow, intermediate-flow (air entrainment mask), or high-flow devices 2
- High-flow nasal cannula oxygenation (HFNCO) delivers oxygen flow rates of up to 60 L/min and has been evaluated for its effect on clinical outcomes, such as improvement of respiratory distress, the need for intubation, and mortality 2
- High-flow nasal prongs (HFNP) offer considerable performance capabilities and may sufficiently meet all oxygen therapy requirements for non-intubated intensive care patients 3
- Conventional oxygen therapy can be delivered via nasal prongs, face mask, venturi mask, or non-rebreather mask, while high flow nasal cannula (HFNC) produces a higher flow of FiO2 4
- Non-invasive ventilation (NIV) and continuous positive pressure support (CPAP) are also used for respiratory support in ICU patients 4, 5
Types of Oxygen Delivery Devices
- Low-flow oxygen devices, such as nasal cannulae and simple face masks 2, 3
- Intermediate-flow devices, such as air entrainment masks 2
- High-flow devices, such as high-flow nasal cannulae (HFNC) and high-flow nasal prongs (HFNP) 2, 3, 5
- Non-invasive ventilation (NIV) devices, such as bilevel positive airway pressure (BiPAP) and continuous positive airway pressure (CPAP) 4, 6
Clinical Outcomes and Safety
- HFNCO has been shown to improve respiratory distress and reduce the need for intubation and mortality in some studies 2
- HFNP has been found to be feasible, safe, and cost-effective for non-intubated intensive care patients 3
- The safety and efficacy of HFNC compared to other oxygen delivery devices, such as low-flow oxygen and NIV, are still uncertain due to limited and low-quality evidence 6