Diagnosing Obstructive Sleep Apneoa
Sleep apnoea is a serious condition that can have detrimental effects on the sufferer’s health and quality of life. Those with OSA don’t usually spot the signs of the condition themselves. It’s often pointed out to them by a partner, family member, or friend that notices the signs of the condition when they sleep.
What are the signs of obstructive sleep apnoea?
The three main symptoms of OSA are:
- Loud snoring
- Noisy or laboured breathing during sleep
- Repeated gasping or snorting during sleep
Some people with OSA may wake up frequently during the night to urinate. Those with the condition may have no memory of waking. This is because the brain often doesn’t wake sufferers fully, but into a much lighter sleep, in order to reopen the airway. Due to these frequent interruptions to their sleep, OSA is often detected by the way the sufferer feels the next day.
Signs of OSA when awake include:
- Feeling very sleepy during the day
- Poor memory
- Poor concentration
- Headaches (especially in the morning)
- Not feeling refreshed upon waking
- Loss of libido
In order to correctly diagnose sleep apnoea, the patient’s sleep has to be monitored. This can be done at either a sleep clinic, or using a testing device worn at home.
It’s helpful for those that suspect they may have OSA to first fill out the Epworth Sleepiness Scale questionnaire or take the STOPBang test. These tests can help to determine whether the patient is at high risk of the condition. In order to eliminate other potential causes of the symptoms (eg. hypothyroidism), a blood test should be carried out. Once all other potential causes of the symptoms have been ruled out, the patient should be sent to a sleep centre to be assessed for sleep apnoea.
Once at the sleep centre, the patient’s height, weight and neck circumference will be measured. This is because being overweight and having a large neck can increase the risk of developing OSA. Sleep specialists should then arrange for the patient’s sleep to be assessed overnight, either by sleeping in the centre itself, or taking some kit home to use while they sleep.
If the patient is going to be assessed at home, the equipment will monitor their breathing, oxygen levels, heart rate and snoring to highlight any abnormalities. If they are assessed at the sleep centre, a polysomnography will be carried out. During a polysomnography, electrodes are places on the patient’s skin, and sensors are places on their legs and finger. A number of different tests are carried out during the assessment, including:
- electroencephalography (EEG) – to monitor brain waves
- electromyography (EMG) – to monitor muscle tone
- recordings of movements in the chest and abdomen
- recordings of airflow through the mouth and nose
- pulse oximetry – to measure heart rate and blood oxygen levels
- electrocardiography (ECG)– to monitor the heart
How serious is OSA?
The severity of sleep apnoea is measured using the apnoea-hypopnoea index (AHI), which measures how many times per hour the sufferer’s sleep is affected.
- Mild – AHI reading of 5 to 14 episodes an hour
- Moderate – AHI reading of 15-30 episodes an hour
- Severe – AHI reading of more than 30 episodes an hour
How is OSA treated?
Losing weight, cutting down on alcohol, quitting smoking, and getting more exercise have all been shown to improve the symptoms of OSA.
CPAP (Continuous Positive Airway Pressure)
The treatment given on the NHS for sleep apnoea is CPAP. Sufferers are issued with a CPAP machine and mask. The mask is worn at night, and it increases the air pressure in the sufferer’s throat; this ensures that the airway stays open and normal breathing continues. 60% of people discontinue using their prescribed CPAP machine, as they find it uncomfortable and inconvenient to use. However, for people with mild/moderate sleep apnoea, a Mandibular Advancement Device (MAD) can prove just as effective.
Mandibular Advancement Devices (MADs)
If the patient is suffering from mild/moderate sleep apnoea, then a Mandibular Advancement Device such as the Snoreeze Oral Device or the Snoreeze LabFit Oral Device has been proven to be just as effective as a CPAP machine. Oral devices work by moving the lower jaw forward, keeping the airway open so the wearer can breathe easily. The neutral position of the Snoreeze devices resolves snoring for many people, but the easily-adjustable design means that the jaw can be positioned forward to clear the obstructed upper airway. Once the airway is cleared, normal breathing can continue all night and snoring is stopped.