When is oxygen primarily delivered during continuous oxygen therapy?

Oxygen is primarily delivered during the first half of inspiration in continuous oxygen therapy because this timing maximizes the amount of oxygen that reaches the patient's lungs and subsequently enters the bloodstream. During the initial phase of inhalation, the airways are expanding, allowing for an efficient flow of oxygen into the alveoli, where gas exchange occurs. This method is particularly effective when ensuring that the patient receives the appropriate concentration of oxygen needed for therapeutic effects.

Delivering oxygen during the entire inhalation phase can also be effective, but focusing on the first half allows for a more controlled and consistent distribution of oxygen when patients are actively drawing air into their lungs. This approach aligns well with the natural patterns of breathing, taking advantage of the dynamics of lung inflation.

In contrast, delivering oxygen only at the end of expiration or during expiration would not provide the same level of immediate benefit, as these phases do not coincide with inhalation and would result in wasted oxygen delivery at times when the patient is not actively drawing in air. Similarly, delivering oxygen evenly throughout inhalation might dilute the inspired gas, potentially leading to less effective treatment. Therefore, focusing on the initial inhalatory effort is more beneficial for patients requiring continuous oxygen therapy.