OSA Diagnostics: How is Sleep Apnea Diagnosed?
How is Sleep Apnea Diagnosed?
Diagnosis starts with your family physician.
There are a number of factors that contribute to poor sleep and it is important to have a thorough medical assessment, which will typically include:
- Completing an Epworth Sleepiness Questionnaire
- Screening for Sleep Apnea using a portable monitoring device, or a simple pulse oximeter that fits over your finger, both are designed for use in the comfort of your own bed at home.
- A full sleep study (polysomnography) conducted in a hospital-based sleep disorder clinic.
Ask us about our FREE Level 3 Sleep Screening Program.
Your physician may recommend that you use a pulse oximeter to screen for sleep apnea. The test is done with the portable monitor in the comfort of your own bed, usually for one night.
The pulse oximeter measures and records your pulse rate and the level of oxygen in your blood while you sleep. The data is then downloaded into a computer and a software will analyze the data the records the reduction in your blood oxygen levels call the Desaturation Event Index (DEI).
Your physician will consider this information, together with other medical symptoms to decide whether to prescribe therapy or refer you to a Sleep Disorder Clinic for a more complete analysis of your sleep issues.
Overnight PSG study can be intrusive, costly, and requires the involvement of both a technician and an interpretative sleep specialist. Portable sleep apnea diagnostic devices provide an alternative to PSG. These devices use unobserved monitoring in the home.
Level Three Sleep Testing Device records the following signals and measurements:
What is a Full Sleep Study?
Sleep disorders are complex medical conditions. If your physician suspects that you have sleep apnea, or another sleep disorder, they may refer you to a hospital or private sleep disorders clinic. You will first receive a consultation with Physicians who specialize in Sleep Medicine and they will assess your symptoms and determine whether you are a candidate for a full sleep study. If so, you will be scheduled to sleep in the sleep lab to conduct an overnight study. During this time you will be tested using Polysomnogram (PSG), which includes an evaluation of sleep staging, airflow and ventilatory effort, arterial oxygen saturation, electrocardiogram, body position, and periodic limb movements.
Measures of Sleep Apnea
The results of a sleep study will show both the type of sleep apnea, and provide a number of measures of its severity.
The Apnea Index (AHI) is the number of apneas and hypopneas per hour.
- Normal is AHI 0-10 events per hour
- Mild 10-15 events per hour
- Moderate 15-30 events per hour
- Severe 30+ events per hour
The degree and frequency of oxygen desaturations may also be an important parameter to measure to assess risk, particularly in patients who are compromised with other underlying cardiovascular conditions.