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Sleep Tests

Routine/Diagnostic Study

Your first sleep study will most likely be a diagnostic study. This involves you coming into the Sleep Centre in the evening. You will get changed into your pyjamas and then the technician will prepare you for the study. Electrodes (a small metal cup on the end of a wire) will be attached to your scalp and face. The electrodes are held in place with either paste or glue on the scalp and tape on the face.

Leads are also attached to your chest to monitor your heart (electrocardiogram, ECG) and your legs (to monitor leg movements). Elasticised bands are placed around your chest and abdomen to detect breathing movement and a probe is put on your finger to measure oxygenation. The skin is cleaned with a degreasing lotion and sometimes areas with too much hair (chest) have to be shaved.

Once this initial setup is completed you can watch TV or read until you are ready to go to bed. The leads are long enough that you can sleep in any position you wish.

CPAP (Continuous Positive Airway Pressure) Trial

Treatment for sleep apnoea (stopping breathing during sleep) involves the use of a nasal CPAP (Continuous Positive Airway Pressure) machine. A mask is fastened over the person's nose with head straps and fastened to prevent air escaping. Depending on the severity of the sleep apnoea, different air pressures may be needed by different people. The first trial of the CPAP machine in the Sleep Disorders Centre is to introduce the sleep apnoea sufferer to the machine and determine the pressure they need to prevent the throat from becoming blocked.

The setup for the CPAP Trial involves all the same leads as the diagnostic study. The
technicians will increase the pressure of the machine until the person stops snoring and they are breathing without obstruction.

A CPAP machine involves the motor unit, to which a tube is attached. This tube is flexible and runs from the machine to the patient. There is a soft mask, which fits snugly over the persons nose and is held in place by a rigid mask and straps. The tube attaches to the rigid mask and it is through this tube that air is blown into the throat.

The soft masks come in different styles and sizes so that you can find one to suit your own needs. The straps and masks also have different styles.

There are other accessories available to make the machine easier to use, such as a humidifier.

MSLT (Multiple Sleep Latency Test)

This test is conducted during the day and usually follows immediately after a routine study. You get up at your usual time, but no later than 7:30am, get dressed and have breakfast (you may want to bring a button up shirt as you have to put your clothes on over the leads).

At around 9 - 9:30am you lie down in a quiet dark room for twenty minutes to see whether or not you fall asleep. After twenty minutes you get up and can watch TV or read or do some work until the next nap which is at around 11 - 11:30am. There are at least four naps finishing at around 3:30pm.

Depending on the results of these four naps you may need to stay for a fifth nap at about 5pm. During the test you are not allowed to have any caffeine as this will affect your sleep.

Follow Up

There are some people who need to have follow-up sleep studies, MSLT's and CPAP trials for various reasons (example: to check the pressure of the CPAP machine). These follow-up studies are the same as the original study.