The Ryan Report
Ryan Diesem
Home Oxygen Guru – The HO2G Pen
Used Oxygen Equipment: Be Aware of Common Issues
New oxygen equipment can be expensive. As we’ve seen these last several years, equipment providers and insurance companies are becoming more selective on the oxygen devices they provide and pay for. This puts an onus on the user to acquire equipment on their own if they want a specific device or if they want to supplement their current equipment (like buying extra tanks). If you or someone you know is an oxygen user, chances are you’ve considered the possibility of purchasing your own equipment from a second-hand source. The aim of this month’s article is to provide some guidance in this endeavor.
I personally feel it is in the buyer’s best interest, when going into the purchase of a used device, to assume that no matter what the seller says, the device does not currently operate to specifications. The buyer should not assume that the seller is fully aware of what the device is supposed to do and/or that the device can still do what it’s supposed to do. For concentrators, especially, when a seller says something along the lines of, ‘It’s barely been used and has just been sitting in the closet for the last year,’ red flags should immediately go up – a concentrator is more susceptible to performance degradation when it isn’t used on at least a semi-regular basis. Some retailers do specialize in refurbishing and reselling equipment, and in those cases the comfort level in buying a device from these organizations can be higher, but potential buyers still should place the burden of proof of operation on the seller before purchasing the equipment.
There are some tools you can equip yourself with if you want to do some spot checking of device performance on your own, although some products may not always be feasible to purchase for limited use. One device every oxygen user should think about owning is an oxygen liter meter. These small, pen shaped devices allow the user to connect straight oxygen tubing (i.e., not a cannula) to the liter meter to check the oxygen flow rate coming 
from the device and make sure it matches the flow setting. These are relatively inexpensive – around $20 to $25 – and come in configurations measuring various flow ranges, up to 15 LPM. For most users, a meter with a range of 0 LPM to 8 LPM will suffice. One important limitation: Liter meters should only be used to measure flow from oxygen devices providing continuous flow. For those with pulse oxygen devices, the pulsemeter is designed to measure pulse output from a device. (Full disclosure: Valley Inspired Products initially manufactured and sold this product. We no longer do.) Pulsemeters are more expensive, around $125 to $150, and can only be used with single lumen pulse oxygen systems (i.e., systems with only one tubing connection), but can measure pulse output within +/- 2 mL. Be aware that not all manufacturers publish their pulse specifications, so depending on the device you may have to research what volume to expect. Lastly, for oxygen concentrators there is a handheld oxygen analyzer, manufactured by Salter Labs, that many home oxygen providers utilize in the field that can measure oxygen purity. When measuring oxygen purity, if the device is not delivering 87 percent or above, it is out of specification. However, this is a very expensive product, $450 to $600 depending on the model! If you are interested in finding out the purity of a device but do not want to buy an analyzer, chances are a local oxygen equipment provider will have an oxygen analyzer on hand, so it could be worth inquiring about bringing the device in for measurements before agreeing to a purchase.
For the various types of oxygen equipment that are out there, here are some things you will want to keep in mind and/or ask about before purchasing:
Portable Concentrators: As mentioned, any POC that has been sitting around unused for a long period of time should raise a red flag. When concentrators remain unused, their ability to generate high purity oxygen may become compromised. Smaller POCs may be more susceptible to this than larger POCs due to lesser sieve material available to separate oxygen. Ask to operate the device at its highest setting for a significant amount of time – at least an hour – to make sure low purity alarms do not sound. Even then, it is possible the device has suffered some performance loss, but is not quite out of alarm specification. Tread carefully in these cases. Ask where the device was stored when not in use – cold or especially humid areas would also be a red flag. Ask about how much battery life the owner was getting when operating the device. Ask if the device was ever serviced, such as having sieve beds and filters replaced. Make sure all of the accessories you would need are included, like AC and DC power supplies, carrying bags and straps.
Stationary Concentrators: Because of the amount of sieve material in stationary concentrators, they aren’t as susceptible to loss in purity as POCs are, but the same questions will still apply. If you have access to a handheld oxygen analyzer, checking purity here is also advised. Ask to see how many hours are on the device – some concentrators will have rolling numbers easily visible. The more hours there are, the chances that output pressure – and thus flow– are impacted, so using a liter meter to measure the oxygen flow rate with extended tubing (25 to 50 feet) at the concentrator’s full range of settings is highly advised. Listen to the device running to see if you can hear any odd sounds from the com- pressor or exhaust that you don’t normally hear with a concentrator. Uneven sounds could mean pressure regulation or leak issues within the unit.
Regulators/Conserving Regulators: Thankfully, regulators tend to be pretty solidly constructed devices with minimal moving parts to be of concern. You will want to check on the inside of the connection yoke (where you place the cylnder stem in) to be sure that the brass/rubber washer is intact.
If possible, have a full cylinder avail- able to place the regulator on and operate the regulator as normal, listening for leak (hissing), making sure flow is coming out at all settings (use a liter meter to check flow rate, if available), and note that the pressure gauge is displaying tank pressure. Check that the flow setting dial moves naturally. Ask if the device has ever been dropped and check for an unnatural shape of the yoke.
Oxygen Cylinders (including home filling cylinders): Make sure the cylinder is green (in the U.S. at least; oxygen tanks are white internationally) with the correct pin index – bring a regulator to verify it will connect. Check the valve stem for any
deformities and if the tank is empty, open/close the valve to be sure the valve does not stick. If you are buying tanks to fill at home, make sure the tank is the exact type for your home fill system – each manufacturer has its own cylinders that you cannot use with other systems. If the tanks have regulators/conserving regulators preattached, check for flow and operating leak at all settings if possible.
A list of websites provides a source where the measuring equipment mentioned can be found, just search for the name listed or contact the company directly.
Oxygen Liter Meter: www.thecpapshop.com www.tri-anim.com
Pulsemeter: www.wairproducts.com www.mountainairemedical.com
Salter Labs Handheld Oxygen Analyzer:
I hope everyone had a great holiday season and that 2018 is off to a great start!
Ryan Diesem is Research Manager at Valley Inspired Products, Apple Valley, MN. Contact Ryan at [email protected] com with questions or comments.