Sleep apnea is a type of sleep disordered breathing.
Sleep apnea is the cessation of breathing during sleep. There are 3 main types of sleep apnea – Obstructive, Central and Mixed Sleep Apnea. The most common form is Obstructive Sleep Apnea. Central and Mixed Sleep Apnea generally require a referral to a Sleep Specialist.
Obstructive Sleep Apnea (OSA) is the cessation of breathing during sleep caused by a blockage of the upper airway, generally due to the collapsing of the soft tissue in the back of the throat. These events can happen numerous times during the night.
During these OSA events the body is still attempting to breathe, but due to the collapsed airway air cannot easily pass through. Obstructions can cause a partial blockage (a hypopnea), or a full blockage (an apnea). These obstructions last a minimum of 10, and often last as long as 30 seconds, and in severe cases can last much longer.
OSA events are coupled with a sudden drop in oxygen saturation levels in the blood, sometimes by as much as 40 percent or more in severe cases. These drops in blood oxygen levels are accompanied by a change in brainwaves – called an arousal – the body’s natural reaction to what it perceives as a type of suffocation. An arousal then interrupts sleep briefly to bring breathing back to normal. These OSA induced arousal events can happen many times every hour, from as little as 5 times per hour (considered mild OSA) to above 30 times per hour (considered severe OSA). In extreme cases arousals have been known to occur over 60 times per hour.
These events significantly fragment sleep patterns. This sleep interruptions, not unsurprisingly, result in excessive levels of daytime tiredness, and in some cases also increased urination during the night, headaches and waking with “brain fog”.
- Waking with brain fog
- Excessive daytime tiredness
- Snoring - usually loud and frequent with periods of silence when airflow is blocked or reduced.
- Snorting, gasping or choking sounds as the airway opens up again
- Increased night-time urination
- Difficulty with efficiency of medications for certain other medical conditions
- Erectile dysfunction
Any person of any age can have sleep apnea, but the chance of developing sleep apnea increases after middle age. The American Academy of Sleep Medicine (AASM) states that:
- About 24 percent of men and nine percent of women have the breathing symptoms of OSA with or without daytime sleepiness.
- OSA with resulting daytime sleepiness occurs in at least four percent of men and two percent of women
- About 80 percent to 90 percent of adults with OSA don’t even know they have it, and remain undiagnosed.
The following groups are at an increased risk of having, or developing, OSA:
- People who are overweight (Body Mass Index of 25 to 29.9), or obese (Body Mass Index of 30 and above)
- Men and women with large neck sizes (> 17 inches / 43.2 centimetres or more for men, >16 inches/ 40.6 cm or more for women)
- Middle-aged and older men, and post-menopausal women
- People with abnormalities of the bony and soft tissue structure of the head and neck
- People with large tonsils and adenoids
- Anyone who has a family member with OSA
- People suffering from nocturnal nasal congestion
- Adults and children with Down Syndrome
- Some ethnic minorities
- People with certain endocrine disorders
OSA is classified into 3 groups based on the Apnea Hypopnea Index (AHI). The AHI is the average number of times that at person has apneas or hypopneas combined per hour of sleep. This is determined through a sleep study. The 3 levels of OSA are as follows:
- Mild OSA – an AHI range of 5-15 (per hour of sleep)
- Moderate OSA – an AHI range of 15-30
- Severe OSA – an AHI range of more than 30
As sleep is such an integral part of the proper functioning of our bodies, the flow on effects of sleep apnea are quite significant. Below are just some of the effects of OSA, beyond just waking tired:
- Fluctuating oxygen levels
- A heart rate that is elevated
- Harder to manage blood pressure
- Increased risk of stroke
- Higher rate of death due to heart disease
- Higher likelihood of pre-diabetes or diabetes, and harder to treat diabetes
- Difficulty concentrating
- Mood instability
- Increased risk of being involved in a motor vehicle accident
- Disturbed sleep of the bed partner
Once an individual has been diagnosed with sleep apnea by undergoing a sleep study, usually in their home but also in some circumstances in a sleep lab, various treatment options are available. The following are different methods of treating sleep apnea, but some are more suited to particular types of sleep apnea than others.
CPAP therapy is the gold standard for treating moderate and severe sleep apnea, and it is also an easy solution for people with mild sleep apnea and for those who just want to stop snoring. This therapy is delivered using a CPAP machine and mask which you wear while you sleep. The CPAP machine delivers a steady stream of pressurised air that supports and keeps your airway open. Most CPAP machine manufacturers produce models that are able to be used for travel and at home allowing you to receive your therapy wherever you need it.
Oral appliances, usually referred to as Mandibular Advancement Splints (MAS), can be used to treat mild to moderate OSA. MAS devices are very similar to mouth guards which secure the lower jaw to the upper jaw during sleep in a way that allows air to more easily pass through. There are temporary MAS devices, and permanent MAS devices which require a mould of one’s teeth.
Both temporary and permanent MAS devices are used only while sleeping. The advantage of a temporary splint is that it is a simple and cost-effective way to determine the appropriateness of a MAS in resolving your snoring or sleep apnea. Temporary splints usually last 1-2 years and then users often progress to a permanent splint that involves a dentist with a background in sleep medicine.
MAS devices are popular with people who are unable to get used to CPAP therapy.
The surgical option is used in limited cases where treatments such as MAS and CPAP therapy have not been successful in treating sleep apnea, and when there is an obvious anatomical issue in the throat. Surgery is performed by an Ear, Nose and Throat (ENT) surgeon. Surgery usually involves removal or reduction of the tissue from the soft palate, uvula, tonsils, adenoids or tongue. Surgery may also involve adjustment of some of the bone structures of the face in more complex cases.
Patients may require multiple surgeries and the solution may also not be permanent. The most common surgery for sleep apnea is a uvulopalatopharyngoplasty (UPP) which reduces the size of the soft palate and can involve the removal of tonsils or adenoids. An adenotonsillectomy is the usual surgical solution for children who suffer from sleep apnea.
CPAP machines are still the preferred solution in the vast majority of OSA cases.
Positional therapy is used for people who have mild sleep OSA that is directly caused by an adverse sleeping position. This basically entails sleeping on one’s side rather than one’s back, which is where sleep apnea is usually worst. Positional therapy only works if there is little to no OSA when sleeping on the side. Raising the head of the bed also helps in some cases.
As OSA is significantly correlated with weight, positive changes to lifestyle are advised. Implementation of the following in most cases reduces the level of OSA:
- Weight loss, and regular exercise
- Ceasing smoking
- Ceasing or reducing alcohol consumption