Screening (Polygraphy examination)
The main reason for an examination at the sleep laboratory (polysomnography) are sleep disorders, but there are other health problems occurring during the night leading to a necessary stay at the sleep laboratory.
Basically, a polygraphy based on a step-by-step diagnosis according to formalities will be conducted at first; this examination is induced by a family doctor or by a registered doctor, mostly an ENT specialist or a pneumologist.
A screening device to be used at home is given to the patient for the first examination of the nightly sleep routine.
THE FOLLOWING IS EXAMINED DURING THE SLEEP:
The patient will return the device next morning for analysis at the practice and to discuss further therapy. In case there is a suspicion of sleep apnea, a polysomnography at the sleep laboratory will be conducted.
Polysomnography is the core of a comprehensive, medical examination of the sleep. It allows the documentation of the individual sleep phases during an entire night. The polysomnography measures various body functions during the sleep and the simultaneous recording of all signals enables our team to evaluate their interaction.
The first stay at the sleep laboratory lasts between one to three nights. This enables the sleep specialists to determine if a treatment with an airway pressure device can solve the problem after the second night, if a sleep apnea is diagnosed during the first night.
THE FOLLOWING IS MONITORED DURING THE NIGHT:
To conduct all these measurements several electrodes and sensors have to be applied to your body. The preparation for these examinations takes about half an hour.
Firstly, the electrodes for an ECG are applied to your chest with a special, harmless glue. They measure the rhythm of your heartbeat. Secondly, two electrodes are positioned on your lower legs to register the movement of the legs during the night. An elastic belt with a sensing element is strapped around your chest and your stomach measuring the movement of your breath. A further sensor records the position of your body during the night. A pulse oximeter is attached to one of your fingers to measure the oxygen saturation of your blood. The nose glasses record possible snoring noises and the flow of your breath with the help of a recorder.
All additional electrodes are attached to your head. The signals for an EEG, an electroencephalogram, showing your brain waves are derived from your scalp and your forehead. The electrodes for the EOGs, electrooculogram, placed close to your eyes record the movement of your eyes. The signals of the EMG, electromyogram, are derived at your chin measuring the tension of your face muscles. Although completely connected by cables, you can and should be able to move as usual.
You may go home after the diagnosis. The gold standard of the therapy is the nightly CPAP- airway pressure (continuous positive airway pressure). To take home you now have the CPAP device and a hose leading to the mask.
There are various types of ventilation:
offers a constant pressure of ventilation
adjusts the pressure automatically to your needs
pressure is higher at inhalation than at exhalation
This pressure difference is either already preprogrammed and fitted to the breathing intervals of the individual patient or the respiration itself regulates the air pressure.
About 30% of the patients cannot cope with this therapy; other alternatives have to be found for them. The lower jaw protrusion braces are a good solution for many sleep apnea patients.
These braces are inserted during the night and relocate the lower jaw and the tongue to the front including the surrounding soft parts – therefore the upper respiratory system stays open during the sleep and there is no further snoring and no interruptions of the breath.
Further there is the possibility to improve the therapy adherence of an airway pressure therapy with an ENT therapy (e.g. uvulopalatopharyngoplasty-UPPP).
A side position therapy using a dorsal position avoiding vest can be prescribed in case of a side position obstructive sleep apnea syndrome.