A senior nurse's claims staff were told to walk away from coronavirus patients in cardiac arrest because of protective gear shortages have been denied.
The whistleblower at Glangwili Hospital in Carmarthen claimed staff were told personal protective equipment (PPE) was not available on the ward.
But Hywel Dda University Health Board denied the allegations.
Its chief executive said it had the right supplies in place and was leading the way on coronavirus care.
Speaking anonymously to the i newspaper, the senior nurse said she fears clinicians and patients were being put at risk because only standard surgical masks and plastic aprons were supplied as protection.
Nurses had been told not to intervene should a coronavirus patient require an "aerosol procedure" such as intubation or suffer an emergency such as a heart attack because higher-spec PPE was not available on the ward, she said.
Staff with training to begin interventions were being asked to call for a medical emergency team from elsewhere in the hospital who would be expected to have adequate PPE, she continued.
But the health board's chief executive Steve Moore, who has recently recovered after being infected with coronavirus, said the health board was battling with "challenging" supply chains but had the right equipment in place.
"I completely understand the fear and anxiety at the moment - and I can understand how these things happen," he said.
"We need to deal with those issues and reassure people as far as we can in terms of what's right for them and their patients.
"We could always do with more [PPE] but this is about being ready for the surge - ensuring that we've got the supply chain issues sorted in time for what we expect to be a big increase in the number of cases. Right now, we have the right supplies in place."
Helen Whiley, director of Royal College of Nursing in Wales, said: "Generally there is a problem with the provision of suitable and sufficient personal protective equipment right across Wales.
"Of course there are some issues with its provision in Hywel Dda as well as we're experiencing this across Wales."