patient returning from a sleep study has a report indicating that his mean ahi is 20 per hour.

by Elsie Mills 4 min read

What is 'AHI' on a Sleep Apnea Test? - Singular Sleep

18 hours ago  · Continuous positive airway pressure (CPAP) therapy to keep the airway open is the recommended treatment option for obstructive sleep apnea. Studies have found that sleeping with a CPAP device can decrease the AHI by 73%. When people with severe OSA use their CPAP devices for at least six hours, their AHI returns to normal levels (below five events per hour). >> Go To The Portal


What does Ahi mean in a sleep study?

The AHI is the number of apneas or hypopneas recorded during the study per hour of sleep. It is generally expressed as the number of events per hour. Based on the AHI, the severity of OSA is classified as follows: Sometimes the Respiratory Disturbance Index (RDI) is used.

How do at-home sleep tests calculate Ahi?

Home sleep tests calculate the AHI based on the total recording time, as opposed to the more precise total sleep time measured in a polysomnogram. As a result, at-home sleep tests often underestimate AHI by about 15%. It is important to note these shortcomings of the AHI, because they can affect treatment.

What is a normal ahi for sleep apnea?

Mild sleep apnea: An AHI of five to 14 events per hour Moderate sleep apnea: An AHI of 15 to 29 events per hour Severe sleep apnea: An AHI of 30 or more events per hour Children are less likely to have sleep apnea episodes.

What does it mean if my AHI is above 1?

Most specialists see an AHI above 1 as unusual for them. A child typically needs treatment if their AHI is higher than 5. If you score moderate or severe on the AHI, you might need to use a CPAP (continuous positive airway pressure) machine while you sleep. With a CPAP, you wear a mask over your nose that’s attached to a machine with a hose.

How many AHI per hour is normal?

An ideal AHI is fewer than five events per hour. That rate is within the normal range. Some sleep specialists aim for one or two events per hour so you're getting better sleep. If the AHI on the sleep study is high, such as 100 events per hour, even lowering it to 10 events an hour may be a big improvement.

What is normal AHI in sleep study?

An AHI less than 5 is considered normal, and some patients with severe sleep apnea may be told by their doctor that they can accept even higher numbers so long as they're feeling more rested each morning, experiencing fewer symptoms and their AHI is progressively decreasing.

What does an AHI of 15 mean?

For an Apnea-Hypopnea Index from 5 to 15 denotes mild sleep apnea. Fifteen to 30 is moderate, while a greater than 30 is considered severe. AHI = sum of the number of apneas (pauses in breathing) plus the number of hypopneas (periods of shallow breathing) occurring, on average, each hour.

What does AHI mean on CPAP?

Apnea Hypopnea Index (AHI) The AHI is the number of apneas or hypopneas recorded during the study per hour of sleep. It is generally expressed as the number of events per hour. Based on the AHI, the severity of OSA is classified as follows: None/Minimal: AHI < 5 per hour. Mild: AHI ≥ 5, but < 15 per hour.

What does average AHI mean?

Apnea-Hypopnea Index (AHI) is a measure of the severity of your sleep apnea. The calculation is a little confusing, but in simple terms it's the average number of apneas or hypopneas you experience per hour of sleep.

What level of sleep apnea requires a CPAP?

All patients with an apnea-hypopnea index (AHI) greater than 15 are considered eligible for CPAP, regardless of symptomatology. For patients with an AHI of 5-14.9, CPAP is indicated only if the patient has one of the following: excessive daytime sleepiness (EDS), hypertension, or cardiovascular disease.

Is sleep apnea a disability?

The Social Security Administration (SSA) no longer has a disability listing for sleep apnea, but it does have listings for breathing disorders, heart problems, and mental deficits. If you meet the criteria of one of the listings due to your sleep apnea, you would automatically qualify for disability benefits.

What is severe sleep apnea?

You're considered to have severe sleep apnea if your breathing stops and restarts more than 30 times an hour. The apnea-hypopnea index (AHI) measures obstructive sleep apnea to determine a range from mild to severe, based on the number of breathing pauses per hour you have while sleeping.

What are the 3 types of sleep apnea?

There are three types of sleep apnea: obstructive, central, and mixed. Obstructive sleep apnea (OSA), the most common, is caused by a blockage of the airway during sleep.

What is considered mild sleep apnea?

“Mild sleep apnea is defined as someone having 5-15 breath-holding or shallow breaths per hour,” Seema Khosla, MD, FCCP, FAASM, and Medical Director at the North Dakota Center for Sleep, tells WebMD Connect to Care. “Mild only refers to this number—it doesn't necessarily mean that someone has minimal symptoms.”

How is AHI calculated for sleep apnea?

To determine AHI, add the total number of apnea events, plus hypopnea events and divide by the total number of minutes of actual sleep time, then multiply by 60. AHI – Apnea Hypopnea Index – The # of apneas and hypopneas per hour.

How is sleep apnea AHI measured?

How Is AHI Measured? The apnea-hypopnea index (AHI) represents the average number of apneas and hypopneas you experience each hour during sleep. To measure it, doctors divide the total number of apneic and hypopneic events5 by the total number of hours you were asleep.

What does AHI mean in sleep?

What Do the Numbers in the AHI Mean? The AHI is the number of times you have apnea or hypopnea during one night, divided by the hours of sleep. Normal sleep: An AHI of fewer than five events, on average, per hour. Mild sleep apnea: An AHI of five to 14 events per hour. Moderate sleep apnea: An AHI of 15 to 29 events per hour.

What is the AHI scale?

The apnea-hypopnea index (AHI) is a scale that tells whether you have a sleep disorder called apnea and, if so, how serious it is. Sleep apnea is when you stop breathing for 10 seconds or more while you’re asleep. A similar disorder, hypopnea, is a partial loss of breath for 10 seconds or longer.

How many events per hour is mild sleep apnea?

Mild sleep apnea: An AHI of five to 14 events per hour. Moderate sleep apnea: An AHI of 15 to 29 events per hour. Severe sleep apnea: An AHI of 30 or more events per hour. Children are less likely to have sleep apnea episodes. Most specialists see an AHI above 1 as unusual for them.

What to do after AHI?

Treatment After a Moderate or Severe AHI Score. If you score moderate or severe on the AHI, you might need to use a CPAP (continuous positive airway pressure) machine while you sleep. With a CPAP, you wear a mask over your nose that’s attached to a machine with a hose.

What is the test that checks your heart rate?

This test is also called polysomnography.

What Is the Apnea-Hypopnea Index (AHI)?

The apnea-hypopnea index (AHI) is a diagnostic tool for determining the presence and severity of obstructive sleep apnea (OSA).

How Is AHI Measured?

The apnea-hypopnea index (AHI) represents the average number of apneas and hypopneas you experience each hour during sleep. To measure it, doctors divide the total number of apneic and hypopneic events 5 by the total number of hours you were asleep. To register as an event, an apnea or hypopnea must last at least 10 seconds or longer.

Understanding the Apnea-Hypopnea Index for Adults and Children

The AHI is measured on a numeric scale. Scores for adults are divided into three categories, which correspond to different levels of OSA severity:

Drawbacks of the AHI

While the AHI can help doctors diagnose OSA, it does not take into account all factors which may point to the severity, or existence, of OSA.

The Impact of OSA Treatment on the AHI

Continuous positive airway pressure (CPAP) therapy to keep the airway open is the recommended treatment option for obstructive sleep apnea. Studies have found that sleeping with a CPAP device can decrease the AHI by 73% 9.

What is a sleep study?

Polysomnography (PSG), popularly known as a ‘sleep study’, has been used for decades to diagnose and evaluate the severity of sleep-disordered breathing. There is a significant increase in the demand for sleep-related evaluations and sleep studies, due to the heightened public awareness of sleep disorders. Sleep-disordered breathing is ...

How often does REM sleep occur?

However, it occupies approximately 25% of the total sleep time. REM sleep cycles occur every 90 to 120 min throughout the night with progressively increasing periods of time. REM sleep is associated with more frequent and longer duration apneas, hypopneas, and severe hypoxemia.

What causes long REM sleep?

Sleep apnea and periodic limb movement of sleep can also lead to long REM sleep latency. Stages of sleep. A sleep study report describes the percentages of various sleep stages. The normal percentage of each stage is reported with the number of total REM Stage sleep cycles recorded overnight.

Why is sleep efficiency low?

A low sleep efficiency percentage could result from long sleep latency and long sleep offset to lights on time with otherwise normal quantity and quality of sleep in between. Many laboratories report total wake time, that is, the amount of wake time during the total recording time in minutes after the sleep onset.

What is stage N1 sleep?

Stage N1 sleep is associated with the transition from wakefulness to sleep and is considered a direct measure of daytime alertness and the subjective refreshing quality of sleep. The quantity and the percentage Stage N1 sleep is an estimate of the degree of sleep fragmentation.

What is the percentage of sleep in stage N2?

Stage N2 sleep predominates the sleep stages with 50% of the total sleep time. It follows the Stage N1 sleep and continues to recur throughout the night. A low percentage of Stage N2 sleep may be a result of sleep fragmentation, increased REM, Stage N3 or a result of obstructive sleep apnea-related arousals.

How much time do you spend in bed?

The amount of time actually spent in bed is an important limiting factor for the total sleep time and sleep stages. A patient who spends only three to four hours in bed cannot reasonably accumulate normal amounts of sleep and may not go to all normal stages and cycles of sleep.

What is the AHI in sleep?

Apnea Hypopnea Index (AHI) The AHI is the number of apneas or hypopneas recorded during the study per hour of sleep. It is generally expressed as the number of events per hour. Based on the AHI, the severity of OSA is classified as follows: Sometimes the Respiratory Disturbance Index (RDI) is used.

Is a person's respiratory disturbance index higher than AHI?

This means a person's RDI can be higher than his or her AHI.

What does it mean to sleep study?

Which means that you’ve spent a night in a polysomnographic laboratory, hooked up to devices that generate an encyclopedic amount of information on what’s going on in your brain and blood, your lungs and limbs.

What is the ratio between sleep time and total recording time?

The ratio between the total sleep time and the total recording time, or TRT, is called the sleep efficiency . People who have significant difficulties in either initiating or maintaining sleep have diminished sleep efficiency , which can be related to various conditions and disorders, including depression. The number of minutes between the time the light is turned out and the person falls asleep is the sleep onset latency. Normally, it takes about 15 minutes to fall asleep. A significantly shorter onset latency–the proverbial falling asleep as soon as your head hits the pillow–might seem desirable, but in fact is an indicator of sleep deprivation. This could suggest a disorder, or it could be just a sign to slow down. Regardless of the demands of work and family, and the enticements of television and the web, you need at least seven and a half hours of sleep a night.

How many stages of sleep do you have?

Sleep Stages. Once you drop off, you should progress through four stages of increasingly deep, dreamless sleep and into a fifth stage during which dreaming–characterized by rapid eye movement–occurs. Over the course of the night, you will cycle repeatedly between Non-REM and REM sleep.

How long does an awakening last?

Arousals and Awakenings. Arousals–interruptions of sleep lasting 3 to 15 seconds– can occur spontaneously or as a result of sleep-disordered breathing or other sleep disorders. Each arousal sends you back to a lighter stage of sleep. If the arousal last more than 15 seconds, it becomes an awakening.

What is the stage of sleep architecture?

The structure of these cycles–poetically known as “sleep architecture”–reveals whether you are getting the restorative sleep you need to feel and be well. Stage 1, the very lightest sleep, should only be 5 percent of the total sleep time, and should only occur at the beginning of the night.

How long does it take to fall asleep?

Normally, it takes about 15 minutes to fall asleep. A significantly shorter onset latency–the proverbial falling asleep as soon as your head hits the pillow–might seem desirable, but in fact is an indicator of sleep deprivation. This could suggest a disorder, or it could be just a sign to slow down.

How many arousals per hour for SDB?

The higher the arousal index, the more tired you are likely to feel, though people vary in their tolerance of sleep disruptions. As few as five arousals per hour can make some people feel chronically sleepy. In the worst cases of SDB, the index can be 100 or more.

What is the AHI scale?

The AHI scale, in chart form, is made up of two columns: AHI and rating. You need to find your AHI score in order to interpret your sleep apnea rating. Here are the AHI values and corresponding ratings you can fall under.

What is the purpose of the AHI scale?

The goal of using the AHI scale is to measure the severity of your sleep apnea.

What is the most important piece of information for sleep apnea?

For sleep apnea test results in particular, one of the most important pieces of information evaluated is the Apnea Hypopnea Index or AHI. If you’re specifically being tested for sleep apnea, you’ll want to know what this diagnostic tool is and how to interpret it.

What are the most common sleep disorders?

Other Sleep Disorders. Besides a sleep apnea diagnosis, you may learn that you have a different type of sleep disorder. Narcolepsy, PLMD (periodic limb movement disorder), RBD (REM behavior disorder) or insomnia are some of the most common ones. These conditions can be treated with medication or even CBT (Cognitive Behavior Therapy).

How can sleep study results be tabulated?

One of the ways your sleep study test results can be tabulated is by a sleep study scoring service. There are several services offered for polysomnograms (PSG) and home sleep tests (HST) that often include sleep physician interpretations. Because the data is compressible and easily transferable, sleep studies may be sent from a sleep center ...

How long does it take to get results from a sleep study?

Sleep Study Results. After your sleep study (polysomnogram or home sleep test) has been performed, there are 8 to 24 hours of data that need to be processed in order for it to be clinically useful. This usually means that the sleep study data will be reviewed by a sleep technologist (RPSGT or RST) and a sleep physician.

Why do sleep studies need to be sent to a sleep lab?

Because the data is compressible and easily transferable, sleep studies may be sent from a sleep center or laboratory to a sleep tech in a different part of the world. The sleep study data is sent and reviewed by a sleep technologist (RPSGT or RST) and a sleep doctor. They are usually contracted for outsource sleep center services.

What is the AHI scale?

The AHI is the measure of how bad the patient’s sleep apnea is. The scale of AHI is: < 5 = normal in an adult. (In a child > 1.5 indicates clinically significant sleep apnea) 5-15 = mild. 15-30 = moderate. > 30 = severe. Now, let’s take this AHI number and break it down a bit.

What is the N1 sleep stage?

Sleep Stages: How much time the patient spent in the different levels of sleep during the study. Non REM sleep stages are referred to as N1, N2 and N3. Here are the “ideal” percentages: N1 is “light sleep” or “transitional sleep.”. This should only account for about 5-10% of the total sleep time.

Can REM sleep cause memory problems?

They may also have muscle pain, or even “fibromyalgia” type symptoms. Second, if they have reduced REM sleep they will feel mentally tired. They may also have memory problems and a “clouded intellect.”. For some of our patients you will be the first one to go over the baseline sleep study with them.

Is REM sleep worse than obstructive sleep apnea?

In REM sleep the muscles have much less tone (some will say paralyzed), and as such obstructive sleep apnea tends to be worse in REM sleep. While there are a lot of things that are fascinating about how sleep works, here are the simple things you need to know and share with your patients.

Factors Affecting AHI Score

Certain factors that can affect your AHI score. So, to reduce your AHI score, it becomes important to know about all these factors and their effect.

How Can I Lower My AHI Score?

As discussed earlier, the AHI score can increase due to a lot of reasons. It can be due to pressure-related factors, sleeping positions, or simply a defect in your CPAP mask, machine, or accessories.

Conclusion

Thus, your AHI score forms an integral part of the CPAP therapy. Try to aim for a score below 5 as that is the most ideal score. Adapt to changes in your pressure and mask, or reduce your alcohol consumption to make your AHI score healthier.