Virtual reality technology has been used at two Melbourne hospitals during a trial to improve child patients' experience of needle procedures.

A 12-year-old cystic fibrosis sufferer has traded his usual kicking and screaming tantrum during blood tests, for a virtual reality dive in an ocean.

Kai, who requires up to 12 vials of blood to be taken twice a year, dreads the pathology appointments and gets distressed by needles.

That's changed since he's taken part in a trial by Monash Children's Hospital and the Royal Children's Hospital, using VR technology to take youngsters on an ocean adventure during the needle procedure.

"There's nothing worse than seeing your child scared, distressed or in pain, so anything that helps calm them down and minimise pain is a huge win not only for the kids, but also for us as parents," Kai's mum Rachelle Stewart said.

"Seeing Kai totally at ease when having the procedure that would usually result in kicking and screaming was definitely a welcome change."

More than 250 children, aged four to 11, having intravenous cannulation or blood taken in emergency and pathology departments at both hospitals took part in the trial.

The VR sequence shows waves breaking and fish nibbling.

The trial found the use of VR reduced pain by 41-60 per cent, anxiety by 35-45 per cent, and parent-rated distress by up to 75 per cent, with most children wanting to use it again.

Paediatric pain specialist Simon Cohen said the trial demonstrated the benefits of distraction in pain management for children.

"Memory of a previous painful experience has a great influence on the pain experience during subsequent procedures," the Monash Children's Hospital doctor said.

"By improving these experiences, we can help both children and parents who require anxiety-provoking and painful but necessary treatments."

The trial findings have been published in The Journal of Paediatrics, and researchers are hoping to expand the use of VR into other departments and hospitals.