Does every patient who snores need to have a sleep study?
This is a question I often get asked by dentists.
Consider a patient like Jane.
Reason for attending; Problematic snoring-sleeping in a separate bedroom to partner.
History: Not tired or sleepy, Epworth Sleepiness Score of only 2. No witnessed apnoeas and no medical comorbidity. BMI in the normal range.
Jane wants an oral appliance, can’t see why she should do a sleep study and the dentist is unsure how to proceed.
Well, I can tell you that sleep physicians I speak with say that if a patient regularly snores, and particularly if it’s loud, this is a sign of obstruction and requires to be assessed with a sleep study, irrespective of the symptoms.
According to Dr Marcus McMahon, a Melbourne based sleep and respiratory physician:
“Symptoms of sleep apnoea have been shown to be poorly predictive of sleep apnoea severity, and the only way to ascertain the true severity of sleep-disordered breathing is to do an objective assessment of their sleep using a sleep study”.
In our clinic, we have seen many non-symptomatic patients who snore, and when a sleep study is done we are regularly surprised to see the presence of significant sleep apnoea.
Over the years it has also become obvious to me that there is not necessarily a good correlation between the degree of symptoms and the severity of sleep apnoea. There are many patients who are extremely tired and sleepy yet have mild sleep apnoea, while others with severe sleep apnoea do not report being sleepy.
There could be many reasons for this including how busy and active a patient is and how much they “run on adrenaline”. Tiredness is very subjective and for some people may seem almost normal if it’s been present over the longer term
There is also the assumption, even by some GPs, that you need to be overweight to have sleep apnoea. Excessive weight is only one contributing factor, and at our clinic, we find that around 30% of patients who have significant sleep apnoea are within the normal weight range. There are many other, often more important causes including anatomical and physiological factors.
Many people also mistakenly believe that just because no one has seen them stop breathing they couldn’t have sleep apnoea. The reality is that much of sleep apnoea can involve partial, not full obstructions in which there is a 50%, or more, interference with airflow. These partial obstructions, called hypopnoeas, are mostly not observed – yet can have a similar impact as full obstructions.
Another point to consider is that if the patient hasn’t had a sleep study you might be treating the snoring well enough with an oral appliance, however, you won’t know whether unrecognised, underlying sleep apnoea is controlled.
Another important consideration is that if the patient thinks their appliance is only for snoring they may not use it when sleeping alone. Even with mild sleep apnoea, your patient could be having over 120 obstructions per night. If they know they are dealing with sleep apnoea, the patient will understand the importance of regular use of their appliance.
So in summary the medical consensus is to organise a sleep study for all patients who habitually snore.
by Dr Harry Ball
BDSc LDS (Melb) M Counsel. (Lat.) Grad Dip Counsell. & HS (La.)
Past co-chairperson dental sleep medicine council of the Australasian Sleep Association.
Co-Director SleepWise Clinic
For details of the next Dental Sleep Institute training program: “Oral Appliance therapy for Snoring Sleep Apnoea & Bruxism” visit the program page here.