We have previously discussed the use of positional devices for the treatment for sleep apnea. These devices are the equivalent of (and possibly the result of) this wives' tale: sew a tennis ball into the back of your shirt and wear it to bed to stop snoring. Positional devices act in a similar way as the tennis ball – they make it so that laying on the back during sleep is uncomfortable. This type of treatment is effective because when an individual with sleep apnea lies on their side, it makes it less likely that the airway will be blocked, and thus, apneas and hypopneas (small apneas) become less likely. But what about those who simply can’t sleep on their sides? What about the back-sleepers who lie miserably with their positional device? There may be hope the back-sleepers in the form of new positional therapy: semi-recumbent sleep (sleeping at a 45 degree angle on the back). Why might this position work? Fluid shifts from the legs to the head during the night (which slightly swells the neck area and increases the risk for apneas), and an elevated head might prevent this fluid shift.
This theory was tested in individuals with sleep apnea and a diagnosis of heart failure. Thirty individuals were recruited, and these research participants underwent a sleep study while lying flat on their back and also while sleeping in a semi-recumbent position. Their apnea severity was evaluated during each night.
It was found that in the semi-recumbent position, the average apnea-hypopnea index (AHI) was about 18, but it was about 30 while the group was on their back (much more severe). Additionally, the index measuring how much time is spent with minimal oxygen in the blood (caused by apneas) decreased from about 22 to 13 events per hour. Finally, sleep stage percentage was quantified to see whether there was more deep, refreshing sleep during one of the two nights. During the night lying completely on the back, a lighter stage of sleep (NREM2) was about 50%. On the other hand, NREM2 was 40% while the participants were in a semi-recumbent position, meaning there was more deep sleep.
So how might we put this knowledge to use? Of course, the best thing one can do for their apnea is to be treated with CPAP or a treatment as effective as CPAP (e.g. an oral device for some individuals). However, for those who are unable to use their prescribed treatment and also have a difficult time sleeping on their side, propping oneself in a semi-recumbent position can be very helpful for reducing apneas.
Source: Basoglu, O. K., Keskin, B., Tasbakan, M. S., & Gurgun, C. (2015). Effect of Semi-recumbent Sleep Position on Severity of Obstructive Sleep Apnea in Heart Failure Patients. Journal of Cardiac Failure.