People who are themselves sleep apnea patients or know someone who has this condition must have heard of AHI, also known as an apnea-hypopnea index. But do you know what the term entails? Are you aware of what is AHI and the method you can use to calculate it? Those who want to find answers to these queries and would like to know ways to improve AHI are recommended to read further. Here you go!
What is AHI?
To understand what is AHI, let us first discuss sleep apnea and what it means to have this condition.
Sleep apnea is a rest problem where the patient stops breathing while sleeping at night. The pauses in the respiratory process are repetitive and might be a few seconds long. Experts use the term apnea to talk about someone who experiences at least ten seconds long pauses. In contrast, hypopnea is when the patient has a partial blockage in the airway and takes shallow breaths.
The apnea-hypopnea index determines the severity of sleep apnea. In addition, it is used to find out the average number of apnea or hypopnea incidents you have per hour while sleeping. So, patients with 2 AHI experience approximately two incidents of apnea or hypopnea per hour for every hour they are asleep.
How to calculate AHI?
Now that we have understood what is AHI, let us see how we can calculate it. The apnea-hypopnea index can be determined as the sum of the number of apnea and hypopnea episodes divided by the total sleep apnea minutes. The result then needs to be multiplied by 60.
What is the normal AHI?
According to doctors, an AHI of less than 5 is normal, and between 5 and 15 is mild sleep apnea. If your AHI index is between 15 and 30, you have moderate sleep apnea, while 30 or more indicates a severe condition.
Experts suggest that children are not much likely to have sleep apnea episodes. They believe that an AHI of more than one is unusual for kids. So, a child experiencing an AHI higher than 5 should be provided immediate treatment.
You must note that the apnea-hypopnea index changes every night and even at night. It is so because the severity of sleep apnea gets impacted by sleep position, mask fit, weight loss/gain, alcohol consumption, and other lifestyle changes.
Note: Some sleep apnea patients might even be told that AHI higher than 5 is also acceptable as long as they are experiencing fewer symptoms and feeling well-rested in the morning.
What is the target AHI with CPAP treatment?
People who are diagnosed with sleep apnea have many treatment options, including oral devices, continuous positive airway pressure machines, and lifestyle changes. In most cases, doctors recommend their patients to use the CPAP treatment because it is effective. During the therapy, the sleep apnea patient is hooked to the CPAP equipment consisting of a mask and tube. They deliver the air into your lungs and open the blockages in the airway.
Even when you are using the CPAP device, your AHI can change every night. So, aiming for a specific number is not ideal. Instead, you should aim to reduce the average apnea-hypopnea index as you continue with the treatment. Whereas the AHI under five is considered normal, an improvement from the prior results is what matters. So, if you are a patient who has reduced the baseline AHI from 100 apneas every hour to 10, it will still be a case of mild sleep apnea, but the treatment would be considered successful. You might experience a significant decrease in daytime sleepiness, cardiovascular health, and blood pressure.
Your healthcare or sleep professional will determine what is considered a good AHI. A sleep study test known as polysomnography will be conducted to determine the baseline AHI. Then, based on the results, the doctor will set realistic AHI expectations after considering your treatment options.
How can I improve my AHI score?
Only using the CPAP machine may not prove successful in completely eliminating the apnea and hypopnea episodes. In some cases, the AHI might go up even when using the CPAP machine. But do not be disheartened, as luckily, there are some ways you can use to improve AHI:
When you are resting on your back, gravity may work against your airway. It might pull against the soft tissues and cause an increase in the AHI. Patients with positional sleep apnea, are recommended to change to the side-sleep position. Doing so can significantly improve AHI.
Many people prefer consuming alcohol before going to bed as it relaxes their minds. But, sleep apnea patients should avoid this habit if their AHI is increasing. The reason is that alcohol relaxes the muscles in the upper airway and increases the chances of collapse. If that happens, the patient is likely to experience pauses in their breathing.
Get a full face mask:
One common cause of air leakage is an open mouth. If you are one of those sleepers who are in the habit of resting with their mouths open, you will lose the pressure out of the mouth. To avoid this, one solution is to use the chinstrap or full CPAP mask. This will help improve AHI and allow you to rest peacefully.
Replace the mask cushion:
If you have been using the mask for a long time, it is normal that the cushion will wear out and the headgear will stretch. When that happens, the air will start leaking from the mask, which means you won’t get proper air pressure at night. Thus, to improve AHI, you should replace the mask cushion in two to four weeks and your headgear every six months.
Adjust the pressure settings:
People who have been using CPAP equipment for a long time might be able to tell you that CPAP pressure settings change over time. This might occur because of alterations in health status like significant weight loss or gain. In such a case, you should adjust the CPAP pressure settings to improve AHI. But, this should not be done on your own. You should change the settings only under the supervision of a healthcare professional.
Replace the CPAP mask:
In time, your CPAP mask may get out of shape and experience wear and tear. It is possible that the frame stretches, bends, or warps, which may result in improper fit and a bad seal. You should undertake some measures to prevent this before it becomes a problem. One of these includes replacing your mask every three months. Afterwards, you should get a new mask.
Even after trying these solutions, if your AHI still remains elevated, it might be a sign that you have other sleep disorders like central sleep apnea or complex sleep apnea. To treat the issues, you may want to try alternative treatments like BiPAP or auto-CPAP (APAP). These help in ensuring that your therapy can maintain the required oxygen levels.
People with sleep apnea should try decreasing their apnea-hypopnea index to improve their condition. In addition to using the CPAP machine, you can try altering the sleep position, replacing the CPAP cushion, adjusting CPAP pressure settings, using a full face mask, replacing the headgear, and avoiding alcohol consumption before going to bed. These steps will help improve your overall sleep.