Patients are dying in ambulances and waiting rooms due to overcrowded emergency departments at North Wales hospitals, say “shocking” letters written by concerned doctors.

In a desperate appeal to Betsi Cadwaladr University Health Board bosses, doctors working at emergency departments at Ysbyty Gwynedd, Ysbyty Glan Clwyd and Wrexham Maelor warned that overcrowding is causing patients to wait up to 24 hours to be assessed.

The letters also say staff are being subjected to abuse due to widespread inefficiencies and call out the “dangerous” practice of keeping patients on trolleys in corridors and crowded waiting rooms during a pandemic.

Doctors describe an incident this summer in which a patient died in an ambulance after waiting two hours for treatment outside a hospital.

However, according to the letters, that death is likely to be the tip of the iceberg.

The letters – which were written in June this year and in December 2020 – were obtained by a Freedom of Information request and passed to the Local Democracy Reporting Service.

In one of the letters, doctors say that “our medical and nursing leadership has failed to address patterns of behaviour that cripple efficiency – that have not evolved for decades”.

They say the overcrowding problem has been compounded by Covid, but explain that it predates the pandemic and follows Betsi being taken out of special measures in November last year after five years.

Special measures can be placed on health boards when external support is needed and patients’ care standards are not being met.

In one of the letters, doctors say: “Our departments have become routinely crowded to the point where delivering even the most fundamental aspects of Emergency Medicine such as rapid ambulance offload, triage, early assessment and investigations, and time critical interventions in sepsis, stroke, cardiac care, major trauma and resuscitation are compromised.

“This is causing identifiable patient harm and mortality with deaths occurring in our waiting rooms, ambulances, and out in the community that are attributable in significant part to delays caused by crowding.

“These catastrophic incidents are currently reviewed in isolation by each site, and we have no evidence or assurance that lessons are being learned over the wider health economy.”

The letter from December 2020 says the health board has been issued with at least a dozen regulation 28 notices, which are interventions by the coroner to improve public safety.

The notices highlight overcrowding and “the lack of meaningful progress on this by the health board”.

Doctors claim overcrowding of emergency departments affects the most vulnerable patients, particularly children and those with mental health problems, dementia or learning disabilities.

They say compassionate assessment of patients requires space, time and unhurried staff.

According to the letter, others put at increased risk were those suffering from self-harm or domestic violence.

The letter from June, which is addressed to Betsi chief executive Jo Whitehead and chairman Mark Polin, reveals that 12-hour waits are common and 24-hour waits increasingly common.

On hearing that a patient had died while waiting in an ambulance, Aberconwy MS Janet Finch-Saunders called for an inquiry.

“It’s absolutely disgraceful, but it is just one of many stories I’m hearing,” she said.

“I’m at my wit’s end with this health board. We’ve had chief executive after chief executive. Each one comes in promising these improvements. I actually believe that senior management are to blame.

“We need an independent inquiry into the non-workings of the health board. The management have been promising to sort this out. I believe it is top-heavy on management and not enough resources are going into front-line staff.

“I’ve been meeting GPs from across the constituency, and they are at the end of their tether. They are so fed up with the way things are.

“They are all overworked. They are having to fill in the void of some of the failings of the health board.”

Clwyd West MS Darren Millar said: “These shocking letters expose the appalling situation in our emergency departments across North Wales.

“The working environment for NHS staff is clearly unacceptable as is the risk being posed to patients who arrive at our hospitals in need of urgent care.

“The leadership of the Betsi Cadwaladr University Health Board must get to grips with these challenges to ensure that patients and staff have access to the support that they need.”

Dr Nick Lyons, the executive medical director at Betsi Cadwaladr University Health Board, said: “I understand the stress, pressure and workload our staff are under, and we need to ensure that colleagues are supported to do their jobs to the best of their ability.

“As with the NHS as a whole, our services are under significant pressure at the moment, which is leading to unprecedented demand on our emergency services.

“There are ongoing challenges to discharge many patients from hospital to suitable accommodation or care services, which impacts flow through the entire hospital system, and on our ability to bring patients into and through the emergency department in a timely manner.

“Our priorities are to continue to improve patient flow in order to release capacity for admissions from the emergency departments and ensure patients receive the best possible care throughout the pandemic and over the winter period.

“We are improving staffing numbers and their skills in our Minor Injury Units and increasing the availability of community care for our frail and elderly patients, as well as continuing to work with our Local Authority partners to try to reduce delayed transfers of care.

“We do ask the public to help us; patients who do not need full emergency hospital treatment may find that they can get appropriate advice and care from other NHS services, including our minor injuries units and local pharmacies.

“Please visit the BCUHB website or contact NHS 111 for advice if you are unsure where to go.