Masks are an integral part of CPAP therapy. The mask used in therapy performs the vital function of facilitating the flow of air such that your airway is kept open during sleep. However, although it is absolutely essential, the CPAP mask is often a source of difficulty for patients. Selecting the right mask is a complex task which requires a solid familiarity with masks as well as a general understanding of CPAP therapy.
The central purpose of the mask is to produce a stable and secure seal around the nose and mouth of the patient. The seal ensures that air does not leak outside of the mask and therefore guarantees that the therapy system remains effective. Masks are available in a variety of sizes; they also come with a range of materials (silicone cushions, gel cushions, etc.) and add-ons. Patients should be able to have a personalized and comfortable fit whatever their head size and facial structure.
Below is a brief outline of the three types of masks used in CPAP therapy. This outline will provide a foundation that patients can use to inform their selection process.
Nasal masks are the most common type of mask used in therapy. Nasal masks offer several valuable benefits for patients and should satisfy patient expectations in the majority of cases. Nasal masks feature a small cushion which rests over the nose; the cushion is removable and can be replaced when it becomes worn from use. In general, nasal masks are able to produce a stable and effective seal more easily than other masks because they cover less area - nasal masks simply cover the nose as opposed to the entire face. Typically, nasal masks include removable headgear and also Velcro straps that permit manual adjustment.
Nasal Pillows Masks
Nasal pillows masks are the least obtrusive masks of the three masks. These designs feature a set of small pillows that sit just below the nares; in the nasal pillow, air is channeled through the nares rather than the mouth. Nasal pillow masks are often attractive to patients because they are less bulky and cumbersome when compared to nasal masks and full face masks. However, it is important to note that, despite their modest size, nasal pillows masks can cause irritation to the nares. Under certain circumstances, nasal pillows masks can be a perfect choice, but they do not necessarily offer superior comfort over other masks in all cases.
Full Face Masks
Full face masks are principally intended for patients who are chronic mouth breathers. Full face masks cover the most area of any mask - they cover the nose and the patient's mouth. Although full face masks are useful for preventing mouth breathing, they are relatively more difficult to seal because they cover a larger area. Many people falsely believe they require a full face mask because they occasionally open their mouth during sleep (specifically as a result of apneas); however, full face masks are typically required only by those who have a substantial nasal-septal condition. Patients who experience minor mouth breathing do not necessarily require a full face mask.
The only other people who stand to benefit from full face masks are patients who sport a mustache. Nasal masks don' seal well against facial hair, so if you don' want to shave, full face might be right for you.
One of the most common concerns among patients is the level of comfort they can expect from their mask. Masks have to be worn at all times during CPAP therapy, otherwise no benefits can be conferred to patients; for this reason it is understandable that the matter of comfort would be near the top of the list of patient concerns. Mask size, cushion material and mask tightness are perhaps the three most significant variables which determine the level of comfort experienced by patients. Fortunately, patients have a measure of choice and can alter each of these factors in order to maximize their comfort.
Whether a given mask feels sufficiently comfortable depends greatly on how patients adapt to the cushion being used. Cushions are typically made of either a gel-based material or silicone; they are also usually available in a range of sizes. It is nearly impossible to predetermine whether a gel cushion or silicone cushion is more appropriate for a given patient; in nearly all instances patients will need to partake in a "trial and error" procedure before they can determine which type of material is optimal. Fortunately, both are sufficiently comfortable for the majority of CPAP users.
In general, gel cushions have a greater ability to produce a customized fit: the gel material is moldable and will adapt to the unique facial contours of each individual patient. However, though it is more malleable, patients occasionally find that gel cushions have to be regularly adjusted in order to maintain a desirable fit and to prevent mask leakage. Silicone cushions are typically softer, lighter and less pliable than gel cushions. Though they are not as adaptable as gel cushions, silicone cushions require less frequent adjustment and are designed to remain in a fixed position throughout therapy.
Both types of cushions have the potential to offer a comfortable experience for patients. In many cases the individual preference for the particular feel of one type of material over the other accounts for which material is used. We recommend that patients experiment with each type of material in order to make an informed decision.
The headgear is an important part of every mask system. Headgear is typically composed of multiple straps which are manually adjustable and allow patients to create an individualized fit. Headgears come in a wide variety of designs - some cradle the top of the head, some wrap around the back of the head, others fit around the lower part of the neck and so forth. The purpose of the headgear is to increase stability and maximize fitness; when used properly the headgear should improve comfort for patients, although it can be a source of discomfort for those who dislike the feel of the straps against their face. If patients can tolerate the texture of the straps, however, the headgear should not cause discomfort.
The other major source of discomfort for patients is mask tightness. Oftentimes patients create an overly tight fit in order to guarantee that they do not experience mask leakage during therapy. Although they may successfully prevent leakage by doing so, they risk compromising their desired comfort level as a consequence. Moreover, on some of the newer masks - particularly the 'inflatable seal' designs - an overly tight fit can actually cause a seal disruption, when the inflated cushion slips off the desired contact point. If patients spend sufficient time and energy it is usually possible to create a fit which is not overly tight and also capable of preventing mask leakage.
Patients have a wide variety of CPAP masks to choose from. Competitors in the CPAP mask market have developed a variety of products which differ in type, style, material and level of comfort. For this reason, it is not at all uncommon for patients to be overwhelmed by the number of options of available. This article will provide several general suggestions which will make navigating the mask selection process easier for patients.
The guiding principle underlying the mask selection process focuses on maximizing seal quality and comfort: patients should always choose a mask which will provide them with a comfortable seal which is highly stable and leak resistant. Successful therapy is not possible without a quality seal and so this must be a central concern for patients.
CPAP Mask Types
The first step patients should undertake when choosing a mask is to determine which type of mask is appropriate for them. There are three types of masks: nasal, nasal pillows and full face masks. By far the most commonly used type is the nasal mask. Nasal masks will be suitable for the vast majority of patients. Nasal masks have a high rate of success in creating a stable, secure seal. The principal reason for this success rate is because nasal masks only cover the nose rather than the entire face; having less area to cover makes achieving a desirable seal relatively easy. Unless they have some special circumstance - such as an inability to breathe through the nose -- patients should obtain a nasal mask.
Nasal pillows masks are smaller and less cumbersome than nasal masks, however creating a desirable seal with nasal pillows is generally more difficult when compared with nasal masks. One of the main reasons patients gravitate toward nasal pillows has to do with comfort: the nasal pillows are placed just below the nose and have less direct contact with the face. If wearing a nasal mask presents a serious comfort issue then nasal pillows may be a correct option.
Full face masks cover the nose and mouth and are worn least often by patients. Full face masks are mainly intended for "mouth breathers" who need a remedy for such breathing. Patients who truly need a full face mask generally have a nasal-septal issue which prevents them from breathing properly through their nose. Full face masks should generally be avoided by those without such an issue because creating a quality seal with these masks is relatively more difficult.
CPAP Mask Sizes
The next step is to identify the size which will provide a secure fit for the patient in question. At the outset, most patients are unaware of what size mask and cushion they require. Determining the correct size will generally involve a bit of trial and error. Patients should be mindful of the fact that some mask frames require a corresponding cushion size which means that they will need to procure a new frame if they wish to choose a different size of cushion. On our site, we do offer sizing guides for all of our masks, which can help give you a better idea of the right size for your particular facial structure.
CPAP Mask Comfort
After determining type and identifying size, patients then need to think about their comfort preferences. Patients can maximize their level of comfort in a number of ways: they can select a specific kind of headgear style, cushion material or mask structure. Patients can opt for a "butteryfly design" such as the one found on the Mirage FX Nasal Mask by ResMed; or they can select a less obtrusive headgear such as the headgear for the Swift FX Nano Nasal Mask which is also manufactured by ResMed.
Cushions are generally available in two kinds of material: gel and silicone. The majority of masks feature a silicone-based cushion. Both gel and silicone cushions have the potential to provide a comfortable experience for patients; whether a patients selects and uses gel or silicone is based ultimately on pure individual preference. Gel is typically able to mold more easily around the specific facial contours of each patient while silicone is often considered softer. Patients interested in a gel cushion should consider the well-known ComfortGel Blue Nasal Mask by Respironics and those interested in silicone should try the Pico Nasal Mask by Respironics.
Patients may need to experiment with different masks before deciding which kind of structure fits their needs. For instance, patients may suppose a large forehead pad is desirable but later realize they prefer a less obtrusive design. Patients may think that a chin strap is necessary but then realize that it is superfluous. In nearly all cases a certain amount of trial and error is expected.
Along with masks, machines are a central piece of equipment in CPAP therapy. Though highly sophisticated and stocked with a plethora of impressive features, the machines used in CPAP therapy are simple to operate and offer a hassle free experience for patients. The function of the machine is straightforward - the machine delivers air at various levels of pressure through the tube and mask and down into your airway. This artificial stream of air will prevent the periodic stoppages which occur in patients who have sleep disordered breathing.
There are three main types of machines used in CPAP therapy: the standard CPAP machine, bi-level machines and auto machines (also referred to as APAP machines). Each one of these machines is functionally different and designed to address specific patient requirements. Below is a brief sketch of each machine and its particular characteristics.
Fixed Pressure CPAP Machines
The standard CPAP machine will supply an air current at a fixed pressure level manually set by your physician. While these pressure levels can be adjusted if your therapeutic needs change, you should not change the pressure level yourself. The majority of fixed pressure CPAP devices have a relatively narrow pressure range -- usually between 4-20cm -- and are unable to accommodate patients who require very high pressure levels. Standard CPAP machines have a variety of comfort features; the exact features will depend of the specific model and brand, but nearly all standard CPAP devices include some type of pressure relief function, leak compensation, ramp function and data management capability. Standard machines come with tubing, filters, power supply, an instruction booklet and a travel bag.
Unlike standard machines, bi-level devices deliver two separate pressure levels during therapy: one pressure level is delivered during inhalation and another is delivered upon exhalation. Moreover, bi-level machines have a wider pressure range than standard machines - most bi-level devices offer up to 25cm or 30cm, and some reach 40cm. These are the most significant differences between bi-level devices and standard devices. Just as with standard machines, bi-level devices come with pressure relief technology, leak compensation, altitude adjustment, ramp function and data management. They also include all of the other equipment necessary to begin therapy.
Patients should be aware that the term BiPAP is often mistakenly used interchangeably with the term bi-level. BiPAP actually refers specifically to the bi-level devices produced by Philips Respironics.
Auto machines - also commonly referred to as APAP machines - have the ability to automatically adjust pressure levels during therapy so that patients receive optimal levels at all times. Auto machines are highly convenient and provide patients with individualized therapy on a consistent basis. As with bi-level machines, auto machines have pressure ranges which are somewhat wider when compared with standard CPAP machines. They include a similar set of comfort features as the bi-level and standard machines as well as all of the required secondary equipment.
In addition to the comfort features which are generally always included with every machine, certain machines also include other advanced features. These advanced features, such as automatic start and stop, will be discussed in the next installment.
CPAP machines include a wide variety of comfort and performance features which serve to maximize outcomes and enhance the overall patient experience. Several basic features, such as pressure relief and leak compensation, are included with nearly every CPAP machine, while other features generally only come with specific models and brands. Below is a list of features which are frequently found in machines of every type (that is, standard, bi-level and auto).
Most CPAP machines come with some form of pressure relief technology. The principal purpose of pressure relief is to increase general comfort. Different machines boast different features, but all have the same basic operation: the level of pressure is decreased during exhalation and then elevated back to its previous level upon inhalation. Various brands trademark their pressure relief functions differently - Philips Respironics has Flex technology, while ResMed calls theirs Expiratory Pressure Relief - but they all serve the same basic purpose.
Mask leakage is a common occurrence in CPAP therapy. Though preventable with effort, mask leakage will likely occur in most therapy systems at some point. Leakage is detrimental to therapy because it prevents patients from receiving their prescribed pressure levels. Most machines - including almost all of the newer models - include some type of leak compensation to help correct leakage. Depending on the model and brand, machines will either feature automatic or manual leak compensation. Leak compensation takes account of mask leakage and adjusts pressure to ensure that patients receive optimal levels during therapy.
The majority of CPAP machines will include either automatic or manual altitude adjustment. Altitude adjustment is ideal for mobile patients who routinely travel for business or pleasure. Altitude adjustment enables the machine to account for differences in altitude and helps maintain consistent pressure levels as a consequence. Most altitude adjustment functions are able to account for altitudes up to 8,000 feet above sea level.
The ramp function is a valuable comfort feature which allows patients to fall asleep before taking notice of the pressure levels generated by the machine. The ramp feature temporarily delays the onset of pressure for a specified period of time; most ramp functions give the option to delay for up to 45 minutes. Ramp also allows you to ease into your prescribed pressure level: pressure starts low at the beginning, gradually rising until it reaches your desired level. This function is particularly useful for beginning patients who have yet to become fully acclimated to the pressure levels of CPAP therapy.
Automatic Start and Stop
Though not as common as other, more basic features, a considerable number of CPAP machines include automatic start and stop functionality. Automatic start and stop technology enables the machine to begin operating immediately after the first breath into the mask is taken and cease operating as soon as the mask is removed. Automatic start and stop technology is a convenience feature as well as an energy conservation feature. Not all patients like automatic start and stop, and if you don' find it to your liking, it can be turned off easily in the patient menu.
Alongside standard CPAP machines and auto machines, bi-level machines are one of the three primary types of devices designed to treat sleep disordered breathing. Whether a bi-level machine is suitable for a given patient depends entirely on their particular circumstances. This article is meant to illuminate bi-level machines and provide a summary of their origin, purpose and functionality.
New sleep apnea patients often assume that bi-level devices were created specifically to meet the needs of persons suffering from central sleep apnea; this is a mistaken assumption. Bi-level machines were actually initially developed so that multiple pressure levels could be used within a single therapy session. Prior to pressure relief technology, standard CPAP machines operated at a fixed level of pressure throughout the entire course of therapy; patients would manually set their pressure level and this level would remain unchanged during therapy. Bi-level machines enabled the machine to operate at varying pressure levels within a single session: bi-level machines would reduce pressure during exhalation and then increase pressure following inhalation.
Although bi-level machines have the capacity to operate at various pressure levels during therapy, this function is now more commonly found on APAP machines. Current standard CPAP machines and auto machines commonly have advanced pressure relief technologies which rival those installed in most bi-level devices.
As the previous section makes clear, bi-level devices occupy a somewhat less robust position within the marketplace in view of recent developments in CPAP and auto machines. However, bi-level machines still have the capacity to deliver exceptional results and may be ideal for certain patients. Bi-level machines typically have a greater pressure range than other machines: nearly all have up to 25cm pressure and many have 30cm. In the near future bi-level machines may be equipped with pressure as high as 40cm. The greater pressure range of bi-level machines means that patients usually receive more desirable pressure levels (and therefore superior outcomes) when compared with other devices.
Patients who wish to receive therapy which is maximally personalized should consider a bi-level auto machine. Bi-level auto machines combine the technologies of both bi-level and auto devices and are able to deliver a highly customized experience. The algorithms within bi-level auto machines are exceptionally advanced: these machines actually have the ability to "adapt" to the specific sleep disordered breathing issues possessed by each individual patient. Bi-level auto machines will detect events and will deliver idealized pressure in response to the particular needs of the patient. In short, bi-level auto machines are the best option for patients who wish to have a highly personalized therapy experience.
Humidification is a highly valuable addition to the CPAP therapy system. Using a humidifier will add a considerable amount of comfort to your experience by preventing or alleviating many of the negative side effects which can accompany therapy. The majority of CPAP machines include a preinstalled humidifier; others require a humidifier to be procured separately.
Human beings have an inbuilt humidification system: when we breathe our sinuses naturally humidify the incoming air and this sustains the lungs. However, our own natural humidification system is not designed to deal with the additional airflow generated by the therapy machine. The CPAP humidifier acts as a supplement to our own ability to humidification system by warming and moistening the incoming air from the machine. In turn, this artificial humidification helps prevent nasal congestion, nasal irritation, nasal dryness and sore throat.
The basic design of the humidifier is quite straightforward: humidifiers have a small water chamber which usually has a water storage capacity sufficient for slightly more than a single session of therapy: typically they have a slot which is meant to connect to your tubing and generally they have a control or dial which can make adjustments. In most cases the water chamber can be removed from the humidifier, which makes filling and maintaining the humidifier quite simple.
Humidifiers are very easy to operate: they are easy to switch on and easy to adjust. In fact, many humidifiers are able to make adjustments automatically so patients will not have to bother with their device at all. Auto adjusting humidifiers will detect changes in the surrounding environment and alter humidity levels accordingly; this ensures that incoming airflow is properly humidified regardless of external temperature or humidity fluctuations.
Rainout is one of the most common issues associated with humidification. Rainout occurs when condensation builds up within the tubing and prevents the humidifier from functioning properly. There are a number of means patients can utilize to help eliminate (and prevent) rainout: patients can attach a tubing cover, obtain heated tubing or obtain a humidifier which naturally protects against rainout. Heated tubing not only helps prevent rainout but also contributes to superior humidification in general. Certain humidifiers - notably certain models by Philips Respironics - detect ambient temperature and automatically make adjustments specifically in order to reduce and eliminate rainout.
As will be discussed in greater detail in a later section, waterless humidification is utilized by smaller, more compact travel CPAP machines. Waterless humidification uses Heat Moisture Exchange (HME) filters which literally humidify the airflow using the patient's own breath: the HME filters capture moisture during exhalation and then recycle it upon inhalation. The upside of waterless humidification is that it allows patients to avoid carrying the bulky equipment associated with traditional humidifiers; the downside is that waterless humidification is less effective than traditional humidification.
ResMed and Respironics - two of the top CPAP manufacturers - have developed heated breathing tubes designed for use with their latest CPAP machines. The heated tubes are an ergonomic addition to therapy, ferrying warm air from the humidifier to your lungs while helping to reduce nasal congestion and rainout. While not necessary, patients who particularly dislike rainout will like using heated tubing.
Waterless humidification is an alternative to traditional water-based humidification systems which uses moisture from a patient's own breath to humidify incoming airflow. Travel CPAP machines, such as the Z1 CPAP Travel Machine by Human Design Medical and the Transcend CPAP Travel Therapy System by Somnetics, utilize waterless humidification in order to remain smaller and more compact than stationary CPAP devices. Waterless humidification, though convenient, is known to have a somewhat lower effectiveness rate when compared with traditional humidification and so patients should be aware of its possible shortcomings.
The functionality of waterless humidification is fairly straightforward: waterless humidification systems use special Heat Moisture Exchange (HME) filters which capture moisture from exhalation and recycle it back during inhalation. This recycled moisture captured by the HME filter ensures that incoming air is humidified. HME filters (such as the HME filter for Transcend CPAP systems) are simple to install and remove. Heat moisture exchange filters have a lifespan between one week and one month; patients should always change their HME filter immediately if they detect even a small drop in general performance.
Because waterless humidification is much simpler than water-based humidification it has fewer controls and fewer comfort features. Hence, patients will not be able to make the same sort of subtle adjustments they normally can make with traditional water-based humidifiers. It is important that patients have realistic expectations as to the comfort typically afforded by a waterless system: waterless humidification systems will provide a basic level of comfort but generally cannot rival the performance of devices with more advanced capability.
Waterless humidification is a convenient innovation which allows travel machines to offer the comforts of humidification without altering their modest size. However, since it is less sophisticated than water-based humidification, waterless humidification systems are not able to provide advanced comfort levels and typically have a lower effectiveness rate. By some estimates, waterless humidification systems have roughly a fifty percent effectiveness rate compared to regular water-based humidifiers.
Managing patient data is one of the most important components of CPAP therapy. In order to derive the most benefits from therapy, patients should be diligent in recording, analyzing and sharing their vital statistical information with their physician. Using a memory card (also commonly referred to as a data card or an SD card) is remarkably simple: the memory card connects to a PC and enables patients to easily analyze their information and share it remotely with their physicians and healthcare professionals. Along with the memory card, patients can also obtain a memory card reader as well as data management software for their PC; these additional tools assist in the overall data management process.
The vast majority of CPAP machines require a memory card in order to upload and transfer therapy information. However, several recent machine models have been equipped with wireless data storage and transfer systems. Memory cards are still widely used and remain relevant for the majority of patients.
The memory card does not actually record the therapy data: the therapy data is recorded by the CPAP machine automatically and stored on the memory card, until it can be transferred to a PC. The amount of data which can be stored varies between CPAP machines. Some machines are able to record and save several years of therapy information. Machines generally have the ability to store different types of information; usually these types are distinguishable based on their level of complexity. Machines which store multiple types of data typically can hold greater quantities of simpler data and smaller quantities of more complex data.
For example, the S9 Escape CPAP machine from ResMed is able to store a diverse range of therapy information; it is able to record data on leakage, sleep quality, usage and so forth. It is also capable of providing a detailed 365 day report which can be shared with a physician quite easily.
Uploading and Transferring Data
The primary function of the memory card is to upload therapy data to a computer so that it may be analyzed and transferred to a physician, sleep specialist or other healthcare professional. After the therapy information is collected by the memory card and uploaded to a PC it can be instantaneously shared with a physician via email. The physician can then analyze the data and provide feedback which can be used to optimize subsequent performance. In order to read the data stored on the memory card using a PC, patients will need to obtain a memory card reader. It is critically important that patients share their data and communicate with their physician on a regular basis as these are means to improve therapy results.
One more important note about memory cards: most major CPAP manufacturers - including ResMed, DeVilbiss, and Respironics - make and carry memory cards compatible with their machines. These cards are sufficient for use, but you do not need to use a manufacturer's card with your machine: any card of the correct size will do, regardless of the manufacturer.
Data management is an essential component of an effective CPAP therapy system. One of the primary tasks of data management is transferring recorded therapy information to a physician or healthcare provider for the purpose of receiving feedback. CPAP machines have the ability to record and save large quantities of complex information which can in turn be used to produce highly sophisticated data reports; physicians can review and analyze such reports and deliver feedback which patients can use to achieve superior therapy outcomes.
Physical and Wireless Transfer
CPAP machines automatically record data once patients begin their therapy routine. In order to access this data for detailed analysis patients will need to have a memory card and card reader. Patients can use the memory card and card reader to examine their information on a personal computer. What's more, the memory card is required in order for patients to deliver data to a physician or healthcare provider.
Transferring therapy data is quick and easy. It can be accomplished in one of two ways: patients can physically deliver their therapy information by handing over their memory card directly to the recipient, or they can deliver their information wirelessly over the internet. The majority of patients today elect to transfer their therapy information wirelessly given that this is the faster of the two transfer methods.
The real benefit of transferring therapy data derives from integrating feedback from the physician or healthcare provider into the therapy routine. After reviewing the report prepared by the physician patients can make the adjustments which are necessary to improve their outcomes - that is, they can adjust their pressure levels, alter their humidification, utilize their ramp function and so forth. Data management is a cyclical process: patients record and transfer their therapy data and then incorporate feedback into their routine, and then patients record their upgraded therapy routine and the cycle continues.