What flow rate in L/min is commonly associated with a high gain in FiO2 using a nonrebreathing mask?

A nonrebreathing mask is designed to deliver high concentrations of oxygen to patients who require significant respiratory support. This type of mask works by providing a reservoir bag that fills with oxygen, allowing the patient to inhale more oxygen-rich air compared to other delivery systems.

The flow rate of 10-15 L/min is considered optimal for a nonrebreathing mask because it ensures that the reservoir bag remains inflated during the patient's inhalation. This high flow rate is essential for achieving a high fractional inspired oxygen concentration (FiO2), typically ranging from 60% to 90%. If the flow rate is too low, the reservoir bag can deflate during inhalation, mixing room air with the oxygen delivered and decreasing the effectiveness of oxygen therapy.

Flow rates lower than 10 L/min would not provide enough oxygen to fill the reservoir bag adequately, leading to a lower FiO2, which is why the other options, with their lower flow rates, would not achieve the desired high gain in FiO2 associated with a nonrebreathing mask. Therefore, the flow rate of 10-15 L/min is crucial for maximizing oxygen delivery and meeting the therapeutic needs of patients with acute respiratory distress or other medical conditions requiring high levels of supplemental oxygen.