He was a ticking time bomb and is sure had it not been for a quick thinking nurse in a chance encounter the next day, he would be dead.

The 19-year-old had fallen off his skateboard at high speed, hitting his arm and head.

His mates took him straight to Calvary's emergency department in the early hours of February 19 where he waited to be treated for more than 12 hours.

He was eventually treated for a broken wrist and sent home.

Mr Askew's mother Jocelyn had trouble waking him up the next day and he continued to complain of nausea and a splitting headache.

They had an appointment at Canberra Hospital for a follow up on his broken bones, but a nurse noticed his behaviour and told him to head straight for the emergency department.

Within hours he was in emergency brain surgery as doctors worked to contain a brain bleed growing bigger by the hour.

"He was walking talking dead," Ms Askew said.

It is one of two cases the hospital has confirmed it has recently reviewed where a brain bleed or aneurysm was possibly missed.

Calvary have defended its actions saying it tries to minimise the use of CT scans due to concerns about cancer.

Studies have shown a small increase in the risk of cancer linked to CT scans, especially for children and adolescents, which has led to doctors showing caution.

But the hospital conceded it should given Mr Askew written information on monitoring his condition when he got home.

"My son was sitting waiting for 12 hours and 40 minutes with six breaks in the hand and the arm, a smashed cheek bone, fractured skull, acute bleed and nobody picked up anything but the arm," Ms Askew said.

Mr Askew presented at Calvary emergency department at 2am on February 19 with a likely broken arm and visible injuries to his head.

Notes say his first observations were taken about 7.30am and he didn't make it past the waiting room until about 11am when he was treated at the recliner chairs.

The family said he only had one other observation taken during his time at the hospital.

He was discharged about 2pm but given no warnings about the signs to look out for after head trauma.

His family believes he showed signs of head trauma at the hospital; complaining of headaches, face pain, vomiting, a severe headache, confusion and not being able to remember the accident.

They said little attention was paid to his head injury or exploring the possibility of a concussion.

"Nothing was ever really said about my head," Mr Askew said.

He and his mother can think of one likely reason - he was dismissed as being drunk.

Mr Askew had a few drinks the night of the fall, about three over four hours.

On his hospital notes - while no breath or blood test was completed - he was labelled as "intoxicated".

"I can't help but feel they've made a judgement call and that judgement call has then affected the whole following processes and protocol," Ms Askew said.

Mr Askew went to Canberra Hospital the morning after being discharged to see a specialist about his broken arm.

It was here an orthopedic nurse named Rosemary took one look at him - at this stage unsteady on his feet and slurring his words - and told Ms Askew to take him straight to emergency.

He was fast-tracked through, given a CT scan and within an hour was in emergency brain surgery.

"They said the clot was sizeable and needed to be removed straight away and had I not gone to emergency and instead taken him home to return the following day for surgery for the arm he would never have woken up," Ms Askew said.

"There was no could haves or maybes, it was simply he would have died."

In a statement a spokesman for the Calvary Public Hospital Bruce emergency department said closed head injuries could be very complex to diagnose and treat and there is clear recognition of occurrences of delayed diagnosis in the medical literature.

"In recent times, the issue of overuse of CT scanning with an inherent radiation dose and subsequent cancer risk is deeply considered by clinicians and often difficult to balance in young patients," he said.

"There are differing views on the respective benefits and problems arising from either a conservative or intrusive treatment approach, and there is no 100 per cent accurate risk stratification tool to assist in decision making.

"In the presence of head trauma, the Glasgow Coma Scale (GCS) is acknowledged within medicine as a reliable and objective way of recording the conscious state of a person for initial as well as subsequent assessment.

"The score helps indicate potential intracranial pressure changes, an observation further informing clinicians around the appropriateness of attending a head CT.

"The score also has some level of prognostication capacity, with a repeatedly normal coma score being reassuring.

"With respect to the two cases identified, Calvary Emergency Department specialists have met face-to-face with one patient and family members and explained the treatment provided and why that treatment was appropriate given the patient's symptoms at the time of their presentation.

"Whilst our doctors provided this patient with advice about monitoring his wellbeing after he left Calvary and returning if his condition changed, we regret we did not provide the patient with written information about monitoring his own condition and remaining observed by others after leaving Calvary."

The family dispute the hospital followed the protocol, saying only two observations were ever done - the first one five hours after he arrived.

"It wasn't like there was a tiny scratch there was a pretty big graze," Mr Askew's younger sister Kelsey said

"You would be willing to take a chance on someone who has fallen off their skateboard at 44km/h and hit their head?

"As far as it concerns me when they sent him home they sent him home to pretty much die.

"It wasn't just that they didn't do the scan but they didn't seem to do a proper check or consistent observations."

In another case also throughout February, a 33-year-old woman said she presented at Calvary twice with symptoms including headaches, dizziness, nausea, loss of consciousness vomiting and pain in one of her legs.

On one occasion she was treated for potassium deficiency and on the next she waited a number of hours in the emergency room before going home.

Her GP, concerned about her symptoms, later organised a CT scan which showed bruising on the brain.

She went to Canberra Hospital where an MRI revealed she had a brain aneurysm and had emergency surgery that night.

Calvary has confirmed it also reviewed her case.

Mr Askew's family wants to make sure no one else goes through what they have.

They want the matter investigated and any holes in the system revealed.

"I thank God every day that I've still got a son," Ms Askew said.