Relatives of Llandough Hospital patients are being urged to use a new service if they're concerned about deteriorating.
The Call 4 Concern initiative allows families to seek immediate help if they're worried that primary healthcare staff have failed to recognise or respond to a patient's deterioriating condition.
The Cardiff and Vale University Health Board says the service is available for familes who have spoken to the ward-based team caring for their patient, but wish to exercise their right for an independent review.
It's also available to relatives of patients at the University Hospital of Wales in Cardiff.
A CAVUHB spokesperson said: "Families are likely to identify signs of deterioration or change in condition much quicker than healthcare professionals, and if this is the case, early intervention is important to ensure patients get the right healthcare support to improve outcomes."
"Patients or their loved ones are encouraged to utilise Call 4 Concern if they have spoken with the team caring for the patient, and still feel concerned that action is not being taken to support the patient."
"By contacting Call 4 Concern, a nurse practitioner from the Patient at Risk Team will be able to support by conducting a review of the patient and implement any appropriate action."
The service aligns with Martha's Rule, which allows patients and families to seek an urgent review if their condition - or that of a loved one - is deteriorating and they feel their concerns are not being listened to.
It's being rolled out in hospitals across England following the death of Martha Mills, who died from sepsis following a cycling accident in 2021. An inquest heard the 13 year-old could have survived if she had been admitted to intensive care, following concerns from her family.
The scheme has yet to be formally introduced in Wales, although a similar Call4Concern service has already been introduced at a North Wales hospital - Ysbyty Gwynedd in Bangor.
The Patient at Risk team can be accessed by calling 07974 285294.