Positional Therapy

Positional apnoea is a specific form of sleep apnoea. The definition used in clinical practice, known as the Cartwright criterion, is a supine AHI at least twice the AHI in other positions. It is not a rare case: the literature places a positional component in a large share of apnoea patients, depending on the population studied and the threshold used.

For these patients, sleeping on the side or the front markedly reduces the number of apnoeas, sometimes below the pathological threshold of an AHI under 5. It is one of the few forms of sleep apnoea where a change in night-time behaviour can complement, or even replace, CPAP.

When should you suspect positional apnoea?

• Sleep study: your report shows a supine AHI clearly above the lateral AHI. For example 25/h on the back against 5/h on the side.
• What your partner notices: loud snoring only on the back, far quieter on the side.
• Variable symptoms: marked daytime tiredness on some mornings, much less on others, depending on the night's position.
• Mild to moderate apnoea (overall AHI between 5 and 30/h): this is the range where the positional component weighs most. Above 30, CPAP generally remains essential.

Ask your doctor for the supine AHI and the lateral AHI from your last sleep study. That is the key figure for knowing whether positional therapy can work for you.

The Night Shift Sleep Positioner: how it works

The Night Shift is a compact device worn on the back of the neck, like a soft collar. An accelerometer detects the body's position in real time.

• When you roll onto your back: the device gives a gentle, progressive vibration, imperceptible at first, rising if you stay supine.
• The principle: the vibration triggers the reflex to turn back onto the side, rather like a partner nudging you, without aiming to wake you.
• Gradual learning: over a few weeks, the body learns to avoid the supine position.

The Night Shift also records night-time data: time spent supine, snoring loudness, sleep quality. A useful follow-up tool to show your doctor.

What the clinical study shows

The figures below come from the study run by Advanced Brain Monitoring, the manufacturer, in patients with positional apnoea. They describe that specific population, not apnoea patients in general:

• A median AHI reduction of 79 % among responders.
• 83 % of participants with positional apnoea saw their AHI fall by more than half.
• 73 % reached an AHI below 10/h on therapy.
• Less sleep fragmentation and fewer desaturation episodes, with reduced daytime sleepiness in a majority of participants.

The device is FDA cleared for the treatment of positional apnoea.

Positional therapy or CPAP: which one?

• Pure positional apnoea, mild to moderate, with a normal lateral AHI: positional therapy on its own may be enough, under medical supervision.
• Mixed apnoea with a positional component: positional therapy alongside CPAP can reduce the pressure needed and improve comfort.
• Severe apnoea with no positional component, AHI above 30 and similar in every position: CPAP remains essential, and positional therapy changes little.
• When travelling: useful as a complement for one or two nights without CPAP, to limit how much the sleep degrades.

Important: never stop CPAP without medical agreement, even if positional therapy seems to be working. A fresh sleep study while using the Night Shift is the only way to validate stopping.

Compatibility with other treatments

The Night Shift works alongside:

• CPAP: simultaneous use is no problem, the neck device does not interfere with the mask.
• A mandibular advancement device: also compatible.
• Hypoglossal nerve stimulation (Inspire implant): confirm compatibility with your surgeon, depending on the model.

See also: the complete sleep apnoea guide, snoring and sleep apnoea, CPAP masks for side sleepers.