From the Guidelines
A full face mask typically delivers oxygen at concentrations ranging from 40% to 60%. For most standard full face masks, the delivered oxygen percentage is approximately 50-60% with oxygen flow rates of 8-10 liters per minute 1. The percentage of oxygen delivered can vary depending on the flow rate and the patient's breathing pattern. Higher flow rates can increase this percentage slightly, while lower flow rates will deliver less oxygen. The mask's fit also affects oxygen delivery, with a looser fit allowing more room air to enter and reducing the oxygen percentage received by the patient. Some key points to consider when using a full face mask include:
- The mask delivers a medium concentration of oxygen, higher than nasal cannulas but lower than non-rebreather masks 1
- The oxygen concentration can be adjusted by changing the flow rate between 5 and 10 L/min 1
- Flows of less than 5 L/min can cause increased resistance to breathing and a build-up of carbon dioxide within the mask 1
- Full face masks are suitable for patients with type 1 respiratory failure but not for those with type 2 respiratory failure 1
From the Research
Oxygen Delivery via Full Face Mask
- The percentage of oxygen delivered via a full face mask can vary depending on the specific device and flow rate used.
- A study published in BMC Anesthesiology 2 found that the addition of a surgical face mask over a Hudson mask resulted in an increased available oxygen concentration, with concentrations ranging from 27% to 38% at flow rates of 2-8 L/min.
- Another study published in Critical Care Medicine 3 found that a Tusk mask could deliver high concentrations of inspired oxygen, with PaO2 levels increasing to 330.0+/-68.9 torr (44.0+/-9.2 kPa) in normal subjects and 378.4+/-61.7 torr (50.4+/-8.2 kPa) in patients with interstitial lung disease.
- A study published in the Lancet 4 described a method for delivering controlled oxygen therapy at a concentration of 60% using a mask with a volume of 300 ml and a flow rate of 30 L/min.
- However, it's worth noting that the specific percentage of oxygen delivered via a full face mask can depend on various factors, including the type of mask, flow rate, and patient's respiratory status, and may not always be explicitly stated in the available research.
Factors Affecting Oxygen Delivery
- Flow rate: The flow rate of oxygen can affect the concentration of oxygen delivered via a full face mask, with higher flow rates generally resulting in higher oxygen concentrations 2, 3.
- Mask type: The type of mask used can also affect the concentration of oxygen delivered, with some masks designed to deliver higher concentrations of oxygen than others 3, 4.
- Patient's respiratory status: The patient's respiratory status, including their lung function and breathing pattern, can also affect the concentration of oxygen delivered via a full face mask 3, 5.