Portable Oxygen Concentrators 101

Basics: there are two types of portable oxygen concentrators; one type only does Pulse Dose and the other does both Pulse Dose and Continuous Flow.

When a doctor writes an order for oxygen in Liters/LPM (liters per minute), that implies Continuous Flow oxygen and not Pulse Dose. The reason for this is that LPM is literally measuring the flow of oxygen over the course of one minute. A machine that does Pulse Dose outputs the oxygen in puffs, or “on-demand.” It’s not flowing continuously, but only when the patient inhales and triggers the machine. So a Pulse Dose machine will never truly deliver liters per minute, because it is not able to. The Pulse Dose only machines give the “puffs” an arbitrary number to coincide with the size of the puff. A single puff is actually measured in terms of the volume, or size, of the puff. To clarify, think of the puff as if it were a drop of water instead. The pulse dose setting is measuring the size of the drop, as opposed to how quickly it’s running down the window pane.

A question that we hear often at AMSR is whether or not it is OK to use a Pulse Dose machine at night while sleeping. Pulse Dose machines are recommended for daytime use only. There are typically two reasons for this: 1) most people mouth-breathe when sleeping or 2) their breath is so shallow that it is not enough to trigger the machine to give them the puff. So, more than likely, the patient would not get enough O2 over the course of the night.

If a doctor wants the patient to have a POC that can be used at night, then it needs to be one that does continuous flow, which is measured in liters per minute (LPM). A unit that only Pulses should only be used while awake, with a stationary unit for night use at home.

So, if the doctor wants you or your loved one to use a Pulse Dose unit, he needs to write the prescription to indicate that; otherwise, you’ll have to get a unit that does continuous flow.

At American Medical Sales & Repair, we will always take the time to qualify our patients for the appropriate oxygen delivery device. We believe that our customer’s should always come first, because when you breathe easier, we breathe easier.

About Scott Ridl: Scott joined American Medical Sales and Rentals in 2008 as a Web Manager and Content Writer. He is a writer and designer. He is extensively trained on oxygen therapy products from leading manufacturers such as Inogen, Respironics, Chart, Invacare, ResMed and more. Scott works closely with respiratory therapists and oxygen specialists to educate the community about oxygen therapy products, COPD, asthma and lung diseases. He writes weekly columns and is passionate about educating the community on oxygen therapy and respiratory issues.

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