Avoid CPAP rainout

Humidification is key to CPAP comfort for so many patients. As we discussed in our blog about why to use a CPAP humidifier, humidified air helps us avoid dry mouth and cold-air related damage to our sensitive lung tissues. However, humidification can cause one uncomfortable side effect: rainout. Below, we’ll discuss how CPAP rainout occurs and how you can avoid it.

What is rainout?

CPAP rainout occurs when heated air cools in your tubing and reaches your mask as water, causing you to get a damp face. It’s an uncomfortable sensation that can wake patients from their sleep due to the feeling of water on their face and/or the gurgling in the tube that condensation can sometimes cause. Once awake, some patients can experience anxiety, particularly those prone to feeling claustrophobic.

Here are some simple steps to avoid rainout in the future:

  • Heated tubing (recommended): Since rainout is caused by heated air cooling in your tubing, a heated tube can sustain that air’s optimum temperature until it reaches your mask. Most heated tubes feature copper wiring that keeps the air inside the tube warm (see ResMed’s ClimateLine™ tubing).
  • A tube jacket: If you already have tubing, you can ask your sleep specialist or home medical equipment (HME) supplier about a standard tubing wrap that keeps the air inside it warm. This is particularly helpful in very cold rooms.

Adjustments are key

Having a CPAP humidifier and heated tubing is half the battle, but it’s still important to set the right temperature levels for both to ensure that your air is heated – but not too heated. If the water chamber is set too high or your tube is too hot, the air can lack or lose its moisture and re-pose the risk of you experiencing dry mouth.

Your doctor or HME can help you set the temperature of your tubing and the level of humidification that your water chamber is producing to achieve your own target relative humidity.

Automated adjustments are better

There is even technology that automatically changes tubing temperature by itself to maintain the humidity level you’ve selected. One example is ResMed’s Climate Control, which constantly monitors the temperature of the air in your mask, and how it’s affected by room temperature and humidity levels. When needed, it simultaneously adjusts your humidifier and tubing levels to keep it constant. This technology is included in all our S9™ and Air Solutions CPAP machines.

This blog post contains general information about medical conditions and potential treatments. It is not medical advice. If you have any medical questions, please consult your doctor.

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