More than half of high-risk patients undergoing surgery do not receive good care, according to a study which paints a “disturbing” picture of some NHS services.

Too many patients are put back on general wards after surgery rather than being sent to critical care, thereby increasing their risk of death, the damning report said.

Experts from the National Confidential Enquiry into Patient Outcome and Death also said a significant number of hospitals are not well equipped for dealing with surgical patients, whether high or low risk.

Data was collected for more than 19,000 patients across 300 UK hospitals.

A case review also examined 829 high-risk patients (who make up about 10 per cent of patients who have surgery in the UK) in detail.

In the general population, about 1 per cent of people can be expected to die after undergoing surgery but this rises to 10 per cent to 15 per cent of high-risk patients.

In the study, almost 20 per cent of high-risk patients whose surgery was planned were not seen in a pre-assessment clinic, which led to higher death rates among this group.

And only 22 per cent of high-risk patients were sent to critical care following surgery. Among those patients who were sent to other wards and where experts believed this was the wrong decision, the death rate more than three times higher.

“It seems shocking that 74 high risk non-elective patients went to a ward after surgery and died there with no escalation to critical care,” the report said.

“Of the 165 high risk patients who died, 80 were never admitted to critical care.”

Even those patients who were eventually moved to critical care had a higher chance of dying than those who went there straight after surgery.

NHS medical director Professor Sir Bruce Keogh said: “The vast majority of operations performed by the NHS are safe and successful, but all patients, especially those at high risk, should receive good care and all the information that they need about their treatment - anything less is simply unacceptable.”

But the Royal College of Surgeons said its own studies had uncovered similar concerns.

Its president Professor Norman Williams said: “It is now time for government to grasp the nettle and ask hospitals to routinely provide publicly available evidence on how they manage high-risk cases.”