Our veteran clinicians share their tips for success for oxygen therapy


Today's Clinician

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Thelma Brooks

Thelma has been a respiratory therapist for 25 years and has been helping respiratory & CPAP patients at Apria for 14 years. When she's not working, Thelma loves spending her time with family and friends, traveling, and shopping.

Q. My portable oxygen unit will sometimes say “low oxygen,” what causes this? 


A. “Low oxygen” can occur on portable oxygen concentrators when the oxygen concentration drops. There are a few things you can do to troubleshoot when this happens. First, check the tubing (nasal cannula) to make sure that there isn't a blockage that would restrict airflow. Second, it is very important that the filters are cleaned per manufacturer guidelines. Check your machine manual to determine if the columns need to be replaced. If you've tried these and the error message continues, contact your local branch to speak with one of our respiratory therapists.

Q. Does my home oxygen concentrator have a filter that needs to be changed? 


A. Yes! These filters are pulling in air and particles from the environment, which leads to a buildup of dust and debris, so cleaning them is critical. Home oxygen concentrators have two filters, a hepa filter and a cabinet filter. The cabinet filter (which is foam) is what will need to be cleaned once per week. Depending on your machine, you can find the cabinet filter on the back or side of the machine, behind a small door. Once the filter is removed, you can clean it by rinsing it under water and setting on a paper towel to dry. Before putting the clean filter back in the device, make sure that it's completely dry. Check your machine's manual for how often you need to replace the hepa filter; you can find machine manuals on

Q. How do I know the settings or liters of air on my concentrator? Mine has just been set for me, how do I know it’s correct? 


A. Oxygen concentrators have a flow meter on the front of the device that commonly ranges from 0.5 to 5 liters per minute, however some models go up to 10 liters per minute. The flow meter will have a flow control knob or dial with a gauge or tube that shows the flow setting. The center of the indicator ball should be on the line next to the flow prescribed by your doctor. Patients can also call their local Apria branch or their physician to ask what the prescribed liter flow should be set at. 

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