Selection of flow rate and concentration of oxygen generator.
by len king on Nov 28, 2022
Oxygen flow rate: This is easy to understand and represents the oxygen flow rate per minute of the oxygen generator. For example: when you inhale oxygen, adjust the flow meter to 5L/min, then the oxygen flow you are currently inhaling is 5L/min.
Oxygen concentration: refers to the oxygen concentration of the oxygen generator. Many people think that only the greater the oxygen flow, the more oxygen we can inhale. In fact, there is no problem with this kind of thinking, but there are many oxygen generators on the market at present, when the oxygen flow is increased, the oxygen concentration will drop. Therefore, the effective oxygen concentration actually inhaled into the lungs cannot achieve the therapeutic effect.
What do these two mean for a patient? For patients with lung diseases that require long-term oxygen inhalation, such an oxygen generator whose oxygen concentration decreases as the oxygen flow increases is of little therapeutic significance.
For example, the most common people who need long-term oxygen inhalation are patients with chronic obstructive pulmonary disease (COPD). The oxygen concentration in our daily air is 21%. In general, the effective oxygen concentration in the lungs of COPD patients needs to be 29% to 35% after inhaling oxygen, and it is stable and continuous to have the effect of treating the disease. We have a calculation method. When using a nasal oxygen tube to inhale oxygen, the effective oxygen concentration reaching the lungs of such patients = 21% + 4% × the oxygen flow rate of the oxygen generator × the oxygen concentration of the oxygen generator.
Assuming that the oxygen concentration of our home oxygen generator is stable at 90%, in order to ensure a certain effective oxygen concentration reaching the lungs, the oxygen flow of the oxygen generator needs to be maintained at 2 to 4 liters.
Conversely, for example, if the effective oxygen concentration in the lungs of a COPD patient needs to be 29% to 35% after inhaling oxygen, and the oxygen concentration of the oxygen generator will decrease as the flow rate increases, then the oxygen generator will be turned on to 2L/min , The oxygen concentration is 50%, applying the formula, the effective oxygen concentration reaching the lungs is: 25%. Open to 3L/min, the oxygen concentration is 40%, applying the formula, the effective oxygen concentration reaching the lungs is: 25.8%. This is far from enough for the effective oxygen concentration of 29%-35% required by the disease.
Therefore, from this point of view, the oxygen generator needs to have a stable oxygen concentration when selecting it, and it should not decrease with the adjustment of the flow rate. If an oxygen generator decreases the oxygen concentration as the oxygen flow increases, it is of little significance for disease treatment.