WATER TRAPS FOR OXYGEN TUBING
Terry from Illinois started a very active discussion about water traps on COPD-Support's email list when she reported that she discovered moisture was settling in her oxygen tubing instead of in her water trap. She recently inserted a water trap in her oxygen tubing, having already hooked up her concentrator's humidifier. She was hoping for some relief from nasal dryness. Instead of relief, she was greeted in the morning with post-nasal drip. Terry sparked an active discussion not only about water traps, but also about the related problems of leaks and problematic hose connections. A good number of suggestions were made, but first:
What are Water Traps?
Water traps are inserted into oxygen tubing to trap moisture that condenses in the tubing. The traps themselves vary in size, however most are cylindrical and between 2 and 8 inches long. They are inserted into the tubing between the humidifier and the cannula, preferably towards the cannula end of the hose. They collect the water that develops in the tubing due to condensation. This allows the user to collect and empty the accumulated water. Water traps should be provided by home oxygen providers, especially if you use a humidifier with your concentrator. You may need to ask your oxygen provider for them. They are also available over the Internet without a prescription.
What's the Cause of Moisture in Oxygen Tubing?
Condensation happens when water vapor in the air turns into a liquid. It is the opposite of evaporation. The accumulated moisture can become a breeding ground for bacteria and/or make its way into your cannula and nostrils. Like the beads of moisture that form on the outside of your cold bottle of beer on a hot summer day (because of the difference in temperature between the bottle and the surrounding air), much the same can happen with your tubing…except the moisture is on the inside, and you don't get any beer. The oxygen coming out of your concentrator is warm, but the exact temperature depends on the particular model of your concentrator—some simply run warmer than others. This might explain why Terry didn't have a problem with condensation until she changed concentrators. The temperature of the air coming out of your concentrator is also affected by the temperature of the air that goes into your concentrator, and the location of your concentrator might influence the temperature of the air taken in. The air coming out of the concentrator picks up additional moisture by passing through the concentrator's humidifier. As this warm, humid, oxygenated air travels down the tubing, the moisture will condense and collect on the inside of the tubing when it hits the cooler areas of tubing, usually on the floor. This is called "rain-out." You can see why this is a bigger problem during the winter months, because warm air rises and floors tends to be cooler than the ambient air. Also, some floors, such as tile and wood floors are going to be colder than carpeting. Multistory buildings often pose fewer problems because of their unique heat distribution.
Reducing the Difference in Air Temperatures
The closer in temperature you can make the air coming out of the humidifier to the air temperature on your floor, the less condensation will develop. Having your concentrator in a well-ventilated area, perhaps even in a cooler area of your home, might make a difference. If your concentrator is bottom vented, avoid placing it on plush carpet, or consider putting a hard surface between the concentrator and the carpet. A small, upside down rug with a hard back might do the trick. To equalize the air temperatures, some people recommend filling the humidifier with refrigerated, distilled water, or even adding a couple of distilled ice cubes to bring the humidified concentrator air closer to the temperature of the air on the your floor. Yet others try to avoid the difference in air temperatures by keeping their oxygen hose off the floor with the use of hooks.
How Can I Get Moisture Out of My Tubing?
It takes a long time to dry out a long stretch of tubing. Unless there is air flowing through the tube, the air inside will become stagnant and the tubing will not dry. The easiest and best solution is to replace the tubing. If you decide instead to dry out the tubing, continue to run air through it until I is dry; just be sure that it isn't humidified air.
Among the great suggestions provided to Terry by members (too numerous to mention) are:
- try to put cotton balls in the water trap (just be sure it doesn't decrease airflow)
- check to be sure the water trap does not obstruct airflow (which seems to be a common complaint)
- be sure you are getting a good flow by holding up your cannula to your ear, or near but not touching your moistened tongue or lips
- consider using an airflow valve before the cannula to compensate for any decrease in airflow
- be aware that the humidifier bottle is a common "weak link" in the system. If you are having an airflow problem, check to be sure the humidifier cap is on securely
- a kinked hose, small leak, or a weak connection anywhere in the system can also decrease airflow
- use a liter meter to test the flow coming out of your cannula end of the tubing
And finally, a big thanks to Ann from Nebraska, for her email that led to this article, in which she declares:
“THANKS! Three years on oxygen and I knew ZIP about water traps!"