Sleep screen (trolley) study

Disclaimer: This fact sheet is for education purposes only. Please consult with your doctor or other health professional to make sure this information is right for your child.

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What is a sleep screening (trolley) study?

A sleep screening (trolley) study is a simple test that helps identify any sleep problems that your child may have. In this study, we measure the level of oxygen and carbon dioxide in your child's bloodstream using sensors on your child's skin, while they sleep.

The results tell us if further testing (for example a full sleep study) or treatment is needed for your child, or the results may be used to change a treatment your child is already receiving. Your child's doctor will discuss with you what they think should happen after the study.

What happens when you arrive at the hospital?

When you arrive at the hospital, ask the staff at the Enquires Desk for directions to the Sleep Unit. Please make sure you arrive at the Unit before 7pm, so we can prepare your child for the study.

The receptionist in the Sleep Unit will book your child in. You'll have to fill out some paperwork and then the receptionist will show you to the David Read Sleep Unit.

It's important that you stay in the Hospital with your child while they're in for the screening (trolley) study, otherwise we can't complete the study.

When you arrive, the Sleep Unit staff will explain what will happen and show your child the equipment to be used so that they are not frightened. This is also a good opportunity for you to ask any questions you or your child may have about the study.

We will provide dinner for your child. If your child is bottle fed or has a special diet, please ring the Sleep Unit on 9845 1150 by 9am on the day of your study and we will place a special order for them from the kitchen. There is a fridge and microwave in the parent room that you can use if you bring food for yourself from home, or you can purchase dinner at the Hospital cafeteria which is open until 8pm (or 6.30pm on weekends and public holidays).

You and your child will each have a bed to sleep in overnight.

What next?

When your child goes to sleep, the Sleep Unit staff will gently put a sensor on your child's finger or toe to measure oxygen and a sensor onto the skin of their chest or stomach to measure carbon dioxide. The Sleep Unit staff will come into the room every hour to record the numbers on the machine. We try to do this quietly and gently to not disturb you or your child while you sleep.

We will monitor your child for at least 8 hours while they're sleeping. Around 5:30am or 6:00am, we'll gently wake your child and disconnect them from the sensors.

As we need to prepare the space for other patients, we do ask that you get up once we've removed the sensors. We will then take the equipment out of your room and look over the results. The doctor will also take blood from your child's arm in the morning. You are free to go home after this is done.

You need to make a follow-up appointment with your referring doctor or Sleep/Respiratory Doctor to discuss the results of the study.

What do you need to bring?

  • Medicare card with your child's name on it
  • Referral letter from your family doctor (GP)
  • Things that will help your child feel comfortable and go to sleep, such as pillows, toys or books
  • Button-up pyjamas (so we can easily put sensors on your child's skin)
  • Toiletries for you and your child - shower facilities are available
  • If your child is on CPAP or BiLevel therapy then you need to bring all equipment (i.e. CPAP/BiLevel machine, mask and tubing)
  • Medications your child uses or may need
  • Enough infant formula and bottles to last overnight
  • Your own pyjamas and a book, magazines etc.
  • Anything else you and your child may need overnight

Please note there's only enough space for one parent or carer to sleep by the child's bed.


  • Please arrive before 7pm on the day of the study
  • You are free to go home after 6:30am the following morning
  • You need to stay at the Hospital while your child is having the study
  • You will get the study results from the doctor who asked for the test
  • You are responsible for arranging the follow-up appointment with your doctor
  • There is hospital parking available for $16. There is also some free parking available on the street.

If you have any questions before arriving, please call the Sleep Unit on 9845 1150.

The Children's Hospital at Westmead

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