Cardiac arrests in hospitals could be prevented if doctors recognise and act on early warning signs more quickly, a health watchdog has said.

More than a third (38%) of cardiac arrests in acutely ill patients could be avoided by improving their assessment and response to deterioration, researchers finds.

Experts from the National Confidential Enquiry into Patient Outcome and Death (NCEPOD) criticised senior doctors for failing their patients by not supporting junior colleagues.

Almost half (47%) of patient assessments when they reached hospital was not good enough, the NCEPOD report shows, and warning signs that a patient was deteriorating and may suffer a cardiac arrest were seen in three-quarters of cases.

The study, Time To Intervene?, finds that warning signs were not picked up in 35% of those patients, not acted on in 56% and not communicated to senior doctors in 55%.

Report author and NCEPOD lead clinical co-ordinator Dr George Findlay said: "The recognition of acute illness, response to it and escalation of concerns to consultants when patients are deteriorating is not happening consistently across hospitals.

"Senior doctors must be involved in the care-planning process for acutely ill patients at an earlier stage and support junior doctors to recognise the warning signs when a patient is deteriorating."

Improved decision-making is also needed for when CPR (cardiopulmonary resuscitation) should be given to a patient and when it should not, known as DNACPR (do not attempt cardiopulmonary resuscitation).

Dr Findlay said: "The lack of senior input fails patients by both missing the opportunity to halt deterioration and also by failing to question if CPR will actually improve outcome."

Even when a DNACPR decision had been made it was not always followed, and 52 patients underwent CPR despite their explicit DNACPR decision, the report finds.

Dr Findlay said performing CPR is the default decision doctors take where no explicit alternative exists, but pointed out: "This does not excuse lack of clarity around the role of CPR for individual patients. CPR status must be considered and recorded for all acute admissions, if not on initial admission then at the first consultant review."

NCEPOD chairman Bertie Leigh said: "In nearly half of all the cases we reviewed there was a failure to formulate an appropriate care plan on admission and a failure, often over several days, to find out what the patient's wishes were, and to carry them out.

"We are at a crossroads. All of us need to recognise and accept the limits of what can be achieved in medicine to the benefit of the patient and a ceiling of treatment described and agreed with the patient wherever possible.

"Doctors should only administer CPR where a patient has consented, or if the doctor is satisfied it is in the patient's best interests."

A Department of Health spokesman said: "Assessment and follow-up monitoring of a patient's condition when they are in hospital is obviously a critical part of delivering high-quality patient care. We expect doctors to ensure that patients are assessed effectively on admission and that changes in their condition are closely monitored.

"It is critical that hospitals have processes in place for junior doctors to escalate their concerns to senior colleagues, and for senior doctors to work with junior colleagues on recognising the warning signs of cardiac arrest at an early stage."