Simple face mask (Hudson mask) can deliver maximum FiO2 of:-
**Core Concept**
A simple face mask, also known as a Hudson mask, is a type of respiratory mask used to deliver supplemental oxygen to a patient. The maximum fraction of inspired oxygen (FiO2) that can be delivered using a simple face mask is limited by the concentration of oxygen in the air that can be inhaled by the patient.
**Why the Correct Answer is Right**
The maximum FiO2 that can be delivered using a simple face mask is approximately 60% because the patient can only breathe in a limited amount of oxygen from the mask. This is due to the fact that the mask cannot generate a pressure greater than atmospheric pressure, and the patient's respiratory rate and tidal volume also play a role in determining the FiO2. The concentration of oxygen in the air is typically around 21%, and the remaining 79% is nitrogen. When a patient inhales through a face mask, they can only take in a small percentage of oxygen above the ambient concentration.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the maximum FiO2 that can be delivered using a simple face mask is not 80%. While high-flow oxygen therapy can deliver FiO2 above 60%, a simple face mask is not designed for this purpose.
**Option B:** This option is incorrect because the maximum FiO2 that can be delivered using a simple face mask is not 40%. This concentration is too low to be of therapeutic benefit in most cases.
**Option C:** This option is incorrect because the maximum FiO2 that can be delivered using a simple face mask is not 90%. This concentration is not achievable with a simple face mask and would require a more advanced oxygen delivery system.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that the maximum FiO2 that can be delivered using a simple face mask is limited, and patients requiring higher concentrations of oxygen may require alternative oxygen delivery systems, such as nasal cannulas or Venturi masks.
**Correct Answer:** D. 60%