Kyran's death in 2013 has been thrust into sharp focus this week with news that a five-year-old boy died hours after he was sent home from Hornsby Ku-ring-gai Hospital.

The circumstances surrounding the boy's death are still being investigated, and Fairfax Media is not suggesting he was misdiagnosed, or his parents' concerns were overlooked.

The case has however raised questions about what parents and carers can do if they are worried their child is getting sick and not getting the medical attention they need.

In NSW, a rapid response program called REACH is designed to enable families to speak up and call for help if a patient is deteriorating while they are in hospital.

Introduced in 2013, the Days have since been working with the NSW Clinical Excellence Commission (CEC) to improve REACH, which stands for "Recognise, Engage, Act, Call, Help is on its way".

"Listening to the parent should be the No.1 rule," Naomi Day said.

"Babies and children don't have a voice, they can't put their hands up and say 'Mummy, something is seriously wrong'. But parents know every little thing about their child. Every cry," she said.

Parents worried their child is getting sicker can:

The program- the NSW equivalent to Queensland's Ryan's Rule - has been implemented in roughly half of the state's hospitals, including Hornsby Ku-ring-gai Hospital and the Sydney Children's Hospital Network. The CEC want to see the program adopted at all NSW public hospitals.

Naomi and Grant Day believe Kyran's death could have been prevented if such an escalation process had been available to them.

"He was a beautiful little boy and he was taken away from us and he shouldn't have been," Naomi said.

The Days had initially trusted the gastroenteritis diagnosis, but when Kyran deteriorated overnight, Naomi knew something was seriously wrong.

"I picked him up and he lay on my chest, something he never did. He was moving his head from side-to-side, and was dazed and very lethargic. He was normally quite loud but he was quiet ???"

"I just had a feeling. You just know when there is something seriously wrong," she said.

Naomi alerted a nurse but was told to wait for the doctor to come in the morning.

"Having your child in that condition and having no one listen to you when you know something is really wrong ??? I have never felt so alone in my life," she said.

Kyran was later diagnosed with intussusception, a condition where the bowel folds on itself.

"To follow everyone to emergency and see your son laying there with 50 million tubes coming out of him and at least 10 doctors there, I just collapsed," Naomi said.

He was flown to Sydney Children's Hospital where he was declared brain dead.

"It breaks my heart and it makes me angry," Naomi said.

"That's what we are fighting for," Grant said. "We did everything within our power to make sure this didn't happen again because Kyran's death was preventable."

The REACH program is not limited to paediatric patients. The escalation system is available to all patients and their families at all participating hospitals.

"Part of the escalation process is making parents and caregivers comfortable so they can raise their hand if they are worried about their child and if there is something wrong," Grant said.

Sharing the Days' story has allowed the CEC to extend the REACH program across NSW, said Dr Bernadette Eather, CEC director of patient safety.

"Parents will know best and we want to acknowledge that and give them the opportunity to speak up when they are worried. They are often in the best position to recognise early signs of deterioration," Dr Eather said.

Every paediatric unit across the state, as well as the main wards and emergency department at participating hospitals should have REACH brochures available and posters on their walls that set out the steps and display the unique rapid response number.

Patients should also be told about the program when they are admitted from an emergency department, Dr Eather said.

"It's about raising your hand and calling for help if you are worried. If they are not getting the action they think is appropriate they can escalate to get a rapid response," she said.

Every time REACH is activated, the hospital should conduct a review and debrief staff to learn from the experience and improve upon it.

Incident reporting data found "deficiencies in patient monitoring" was the second most common classification for root cause analyses in NSW.