Temperature
The air temperature plays a key role when discussing humidification. At any given temperature air can hold a specific amount of water vapor. Basically the higher the temperature the more capacity the air has to hold water vapor.
Relative Humidity
Relative humidity is the ratio of actual water vapor in the air compared to how much water vapor the air is capable of holding (its capacity). Relative humidity's unit of measure is %.
Absolute Humidity
Absolute humidity is a measurement of actual water vapor content per volume of air, measured in milligrams of water vapor per liter of air {mg H20/L}.
Dew Point
The temperature level where a fully saturated gas begins to condense. (This is often referred to as rain out in a patient circuit.)
In the example below, the water vapor content per liter of air (absolute humidity) is identical in both cases @ 44mg H20 / L. However, the 37 degree C cube must have a relative humidity level of 100% to enable 44 mg H20 to be present when compared to a 67% relative humidity level at the higher temperature level of 45 degrees C. The warmer the temperature the greater its capacity for holding water vapor.
Difference between Cool Pass-over & Heated Humidification
Cool pass-over style humidifiers allow the air flow to pass over a pool of water and subsequently pick up water vapor by free evaporation. Typically the larger the surface area of the pool of water the more water vapor the air stream can pick up. This is why Respironics' LX Humidifier and the new REMstar Pass-over Humidifier provide additional humidification capabilities vs. a non-heated canister-type water chamber with minimal surface area.
The REMstar Heated Humidifier is also a pass-over style humidifier but it is heated. Heated pass-over style humidifiers are much more efficient at providing humidification simply by increasing the water temperature, which increases water vapor production vs. free humidification (see picture below). By increasing the water temperature, additional energy is added to the individual molecules, allowing more of them to transform from the liquid state. As a result, the heated humidifier has the capability to provide additional water vapor to the air stream vs. a typical cool pass-over design.
Bacteria and the Chamber
Heated humidification produces molecular water vapor (.0001 microns in size) that is too small to transport bacteria into the air stream that is delivered to the patient. If small amounts of bacteria are present in the chamber there is little risk to the patient. Bacteria requires a carrier and molecular water vapor cannot provide this mechanism.
Note: The humidifier chamber does offer good conditions for colonization by micro-organisms such as bacteria. This has been demonstrated over the years with other respiratory devices. This fact highlights the importance of proper and frequent cleaning of the humidifier chambers.
Distilled water vs. tap water
Most tap water contains various minerals. When a pool of water is heated and evaporated, these minerals are left behind and may cause discoloration to the aluminum plate and plastic housing of the humidifier chamber. It may adversely affect the longevity of the chamber. Distilled water has been purified and will not generate mineral residue upon evaporation and may extend the usable life of the chamber.
Comfort Tips
Respironics has developed unique product features to make positive airway pressure more comfortable to use, such as C-Flex, ramp, humidification, and Comfort Series masks.
C-Flex
C-Flex lowers the pressure at the beginning of exhalation when many people find therapy most uncomfortable. The amount of pressure relief is based on your breathing pattern and your C-Flex setting. With three C-Flex settings, you have the ability to select a greater or lesser degree of pressure relief that is right for you.
Your device should be set up with a preset C-Flex setting. You can try other settings by simply pressing the C-Flex button on the front of your device. You may also change the C-Flex setting using the control buttons and display screen. Press the right arrow to scroll to the C-Flex settings page. A screen with three C-Flex settings will appear. Use the C-Flex or plus and minus buttons to increase or decrease the setting. Press the stop/start button to save your setting and return to the mail menu.
Note: If C-Flex is not enabled on your device, talk to your doctor or home care provider about activating it.
Ramp
Ramp is a comfort feature on all M Series devices. Ramp allows you to keep the air pressure low when you are trying to fall asleep. And then it automatically and gradually increases the air until your prescription level is reached. Many users find that using ramp makes it easier to fall asleep. You activate the ramp by pressing the ramp button on the front of your device. Most of the PAP devices allow you to set the starting ramp pressure to the level you find most comfortable. And if you wake up in the middle of the night and have a hard time falling back to sleep, you can activate ramp again by simply pressing the ramp button.
Humidification
The humidifier is another piece of equipment that will make your therapy more comfortable Heated or unheated humidification can reduce discomfort associated with common CPAP conditions such as dry mouth, nasal irritation or congestion.
To make humidification even more comfortable, we’ve made the M Series humidifiers even easier to use. The M Series humidifier features a new easy-turn dial to get the right setting, and it doesn’t need to be reset during the night if therapy is temporarily suspended. Plus, the redesigned “hidden” water chamber is easier to use and easier to fill and delivers continuous humidification throughout the night.
Comfort Series Masks
Comfort with your therapy is closely tied with the kind of mask you use. When you find a mask that is comfortable, you have the best chance to enjoy the full benefit of therapy. Respironics Comfort Series line offers a variety of styles, features, and sizes designed to fit many different facial profiles and user preferences. Sometimes getting a better mask fit is as easy as adjusting the headgear – especially if it’s too tight. Adjusting to your mask means learning to accept its presence. It may take some time, so be patient and stick with it.
Regular use means living a longer and healthier life!
It is very important to get comfortable with your device so regular, all-night positive airway pressure sessions become part of your nightly routine. People who regularly use positive airway pressure therapy feel healthier and more alert. So make a commitment to accept therapy as part of your life and use your device each night. The more you know about your treatment and sleep apnea, the better prepared you will be to live a longer, healthier, and more productive life.
Travel Tips
The M Series Sleep system is easy to pack up and carry along when you travel. The standard carrying case holds the M Series sleep system with integrated humidification. The tubing and mask can be packed in the collapsible front pocket of the carrying case. Optional travel accessories are available for purchase.
How to Prepare for Travel
Traveling with the integrated humidification platform
To prepare for travel (this includes travel to and from the physician or homecare provider):
- Unplug the device and pack the cord and power supply in the front compartment of the carry case.
- Verify that the humidifier water chamber is empty and completely dry to prevent water from spilling in the device during travel. You may want to place the humidifier water chamber in the collapsible front pocket of the carrying case with your mask and accessories in case you do not have time to dry the humidifier properly.
Traveling without the integrated humidification platform
To prepare for travel:
- Unplug the device and remove the water chamber.
- Remove the tubing and swivel from the outlet port on the back of the device.
- Disengage the device from the humidification platform.
- Disconnect the power supply from the humidification platform.
- Remove the Air Outlet Port from your carry case (located in the front corner pouch in your carrying case) and place it on the back of the device where the tubing is connected. Gently snap it into place. You will be unable to connect the patient breathing circuit to the device if this Air Outlet Port is not present.
- Pack the power supply, adapter cord and device in the carry case.
Airport Travel
At most airports, security personnel is familiar with sleep apnea devices. If they are not, there is a marking on the bottom of the device that clearly states it is a medical device.
International Travel
The power supply works on voltages from 100 to 240 AC. You may need an international plug adapter to make your power cord work in different countries.
Boat or Motor Home Travel
If you plan to travel by boat or motor home, Respironics offers a 12-volt DC power cord that can be used to operated Respironics’ CPAP systems for which AC power is not available. The cord plugs into a standard cigarette lighter socket found in most automotive vehicles. These can be purchased separately here at EasyCPAP.com.
Elevation Changes
Sometimes you change elevation as you travel. The REMstar Pro, REMstar Auto, BiPAP Plus and BiPAP Auto automatically adjust to these changes in altitude. You must adjust the altitude setting manually on the REMstar Plus.
Travel Accessories
Travel Cases
For those who prefer not to travel with their humidifier, Respironics offers a compact travel case for the CPAP unit and a lightweight zippered pouch for your mask and accessories. These items will fit nicely into your luggage. The case and accessory bag are available for purchase separately or as a travel pack. Please contact your provider for more information.
Power Accessories
Respironics offers several power accessories to enable regular use of your therapy system when away from home. All of these items can be purchased separately here at EasyCPAP.com.
- 12 Volt DC Cord to operate Respironics’ CPAP systems when AC power is not available. The cord plugs into a standard cigarette lighter socket found in most automotive vehicles.
- DC Battery Adapter Cable for use with any 12 VDC deep cycle marine-type battery. Note, the battery adapter must be connected to either the DC Interface Module or the DC Cord to enable operation.
- Portable Battery Pack provides up to 26 hours of operation and can be recharged in approximately 10 hours or less with the 12V universal battery charger. The entire system is easily transported in a carrying case. The charger and battery may be purchased as a system or separately.
REMstar Humidifier Water Chamber 
