PAP Pressure Settings vs. CPAP: Differences Explained

CPAP (Continuous Positive Airway Pressure) and APAP (Auto-Adjusting Positive Airway Pressure) are two different types of positive airway pressure used in the treatment of sleep apnea. They differ in the levels of air pressure they release to provide comfort and therapeutic effect. 

Understanding the pressure settings and finding the correct pressure setting for you can  be complicated to begin with but once you find the right pressure setting it can have a significant positive impact on the quality of your sleep and improve your overall health and well-being.

If the pressure settings of your machine are too high then you may experience symptoms such as difficulty breathing, dry mouth or mask leaks. If the pressure is too low then the symptoms of sleep apnea will continue despite using your machine consistently. This includes frequent and loud snoring as well as interrupted and poor quality sleep. 

Therefore, determining the correct pressure setting is essential for managing sleep apnea successfully and ensuring a more comfortable experience.

The difference between the two types of therapy is that APAP machines adjust the pressure setting based on breathing patterns whilst CPAP machines deliver a constant pressure throughout the night, keeping the airways open. Both work using a mask connected to a small machine that pumps air into the airways to reduce the symptoms of sleep apnea.

In this guide we will examine both CPAP and APAP technologies, compare their pressure settings, and discuss the factors to consider when choosing the most suitable option for you. We can help you find the optimal pressure for a good night’s sleep.

Understanding CPAP and APAP Technologies

What is CPAP?

Continuous Positive Airway Pressure (CPAP) is the most commonly prescribed treatment for obstructive sleep apnea (OSA). OSA is when the throat muscles relax during sleep, causing the airways to narrow or collapse resulting in  shallow or interrupted breathing. It is the most common type of sleep apnea. 

A CPAP machine works by delivering a continuous and fixed air pressure level throughout the night, preventing the airway from collapsing so that you can breathe effectively throughout the night. 

The pressure setting for a CPAP machine is determined by your doctor or healthcare provider after carrying out a full analysis of your symptoms. This often includes a sleep study or CPAP titration, where the optimal pressure level is identified to keep your airways open. 

The advantage of CPAP is that the pressure remains consistent throughout the night, regardless of changes in sleep position or stage of sleep. However, some patients may find it uncomfortable or difficult to adjust to the constant pressure level.

What is APAP?

Automatic Positive Airway Pressure (APAP) is a modern and advanced form of positive airway pressure therapy used in the management of OSA. Although CPAP is the gold standard, APAP has become more commonly prescribed because it can adjust to your individual breathing patterns during sleep. 

Unlike CPAP which delivers a fixed pressure, APAP machines use algorithms and sensors to determine the correct air pressure level required throughout the night. It continuously monitors your breathing and responds to changes such as sleep position, stage of sleep, and the occurrence of apneic events like apneas, hypopneas, or flow limitations.

This ensures that you are receiving the exact amount of pressure needed at any given moment, enhancing comfort and efficacy. APAP machines, such as those with ResMed’s AutoSet technology, are particularly beneficial for patients with complex sleep apnea conditions, such as REM-related apnea or positional apnea.

In this case you may require higher pressure settings at certain times in the night and lower settings at others. CPAP therapy cannot adapt to meet these requirements which means that APAP is a highly preferable alternative. 

Comparing APAP and CPAP Pressure Settings

Pressure Flexibility

As you can see there are many differences between APAP and CPAP. One of the most significant differences is the level of flexibility they offer with regards to pressure settings.

CPAP machines deliver a fixed, constant pressure throughout the night, which is determined during an initial sleep study or CPAP titration. The pressure remains the same regardless of changes in sleep position or stage of sleep.

In contrast, APAP machines use sensors and algorithms to automatically adjust the pressure levels as required, and use the minimum pressure necessary. It is ideal for patients with fluctuating sleep patterns or those who experience different levels of airway obstruction throughout the night.

Impact on Sleep Quality

The type of pressure setting used can impact the quality of your sleep. Many patients on CPAP find that the air pressure may be too high or too low. If it is too high then it can cause a range of symptoms such as difficulty breathing, dry mouth, interrupted sleep and general discomfort. 

If the pressure is too low then the airways are likely to collapse resulting in inadequate treatment. In this case you would have to return to your doctor or healthcare provider for a reassessment to determine a better pressure setting for improved results.

With APAP however, the machine is able to provide a personalised therapy which can be more comfortable and help reduce the symptoms of sleep apnea more effectively resulting in better quality of sleep and improved health and well-being. 

Utility in Different Situations

Whether or not CPAP or APAP is more suitable for you depends on your individual health requirements as well as your personal preferences. For patients with consistent sleep patterns and a well-defined airway obstruction, CPAP therapy may be the most effective form of therapy. It is the most established form of PAP and has been used successfully for many decades. It is simple and cost effective and generally easier to use and maintain. Despite advances in medical technology it remains the therapy of choice amongst many patients. 

For patients with complex or variable sleep apnea conditions, such as those with REM-related apnea or positional apnea, APAP may be more effective for managing your symptoms. It can adapt to your changing needs throughout the night providing a higher pressure where necessary or minimum pressure as required. 

It is suitable for patients who experience fluctuating airway obstruction levels throughout the night. It is also preferable for patients who have difficulty adjusting to the higher pressures of CPAP therapy, making the therapy more comfortable and effective for a wider range of patients.

Choosing Between APAP and CPAP: Factors to Consider

Patient-Specific Needs

As mentioned, it is important to consider the individual requirements of the patient. CPAP is suitable for patients with consistent sleep patterns and simple OSA whereas APAP is a preferred alternative for patients with complex or variable OSA. 

With its “auto CPAP pressure settings,” an APAP device can adapt to changes in sleep position, alcohol consumption, or weight fluctuations, which helps provide a personalized approach. This can be achieved with machines such as “ResMed AirSense 11”.

Patients who find it difficult adjusting to fixed high pressures or constant airflow of CPAP may find APAP more comfortable. The dynamic pressure adjustments in APAP machines can help reduce side effects such as mask leaks, aerophagia, and breathing difficulty, providing greater comfort and therapeutic effect.

For pregnant patients, APAP is the preferred form of therapy as it can adjust to the changing needs that occur during pregnancy. Patients can enjoy optimal therapeutic effects without the need for repeated sleep studies.

Doctor’s Recommendation and Prescriptions

Your doctor will be able to recommend the most suitable option for you. Doctors recommend CPAP for patients with CSA or complicated OSA, whereas in patients with simple OSA APAP is the preferred prescription. 

Studies show that both CPAP and APAP are effective for managing the symptoms of sleep apnea. The choice should be determined by taking into consideration the patient’s individual requirements as well as their personal preference.

 Comfort is just as important as effective treatment especially for compliance. If your machine is uncomfortable then it is unlikely that you will use it consistently and this can affect the treatment process and impact your health and well-being. 

In some cases, your doctor may recommend CPAP to begin with however if you are uncomfortable or the treatment is ineffective then you may switch to APAP as necessary. This helps make sure that you receive the most appropriate and comfortable treatment for your specific condition.

Cost and Insurance Coverage

The cost and insurance coverage of CPAP and APAP machines are also important factors to consider. Generally, APAP machines are more expensive than CPAP machines due to their advanced technology and automatic pressure adjustment capabilities. The cost of maintenance and supplies should also be considered.

While the initial cost of an APAP machine may be higher, the dynamic pressure adjustments can sometimes reduce the need for frequent adjustments and additional sleep studies, reducing costs in the long run.

Conclusion

Both CPAP and APAP are effective in the management and treatment of sleep apnea. Which is more suitable for you depends on your individual requirements as well as your personal preferences. CPAP provides constant air pressure throughout the night whereas APAP provides the necessary air pressure depending on your requirements throughout the night.

Your doctor will be able to help you decide which is the most effective form of therapy for your symptoms. They will also take into consideration your personal preferences. It is likely that your doctor may recommend CPAP for simple sleep apnea whilst recommending APAP for more complex cases.

The cost of the machines vary. Due to the advances in technology APAP machines are more expensive than CPAP machines. CPAP machines are simple to use and maintain whilst APAP machines provide a more personalised treatment option. Your doctor will assess your symptoms and help choose the best form of therapy for you.