Thursday’s strike by 10,000 HSE support staff is set to go ahead after talks at the Workplace Relations Commission ended without agreement.
Leaving today's talks, SIPTU Health Division Organiser Paul Bell acknowledged that Thursday's strike would have an impact on hospital services and patients, and described the current situation as "most serious".
Mr Bell said local strike committees will now engage with local management on contingency arrangements for Thursday.
He said SIPTU regretted any disruption caused to patients and pledged to try to minimise the impact on them.
Asked how patients in hospitals would be affected on Thursday, Mr Bell said a lot of services delivered by support staff which were taken for granted would become apparent - including the feeding of patients, administration, and transportation of patients around hospitals.
He warned that if the dispute is not resolved, five further strikes will take place over the coming weeks.
He insisted the dispute was not just the responsibility of SIPTU but also the responsibility of those who managed hospitals and the Department of Public Expenditure and Reform, who had nothing new to offer today that would enable the union to defer the strike.
As yet it is unclear whether the strike action, which will hit 38 hospitals, will trigger cancellations of patient appointments.
The Health Service Executive had said it would not be commenting until today's talks end but would continue to strive, as far as possible, to have the industrial action averted and to ensure the impact of any action is minimised in respect of people using their services.
A spokesperson for the Minister for Public Expenditure and Reform said: "There are well established procedures under the terms of the PSSA to utilise, to the maximum effect, the industrial relations machinery of the State.
"The employer side remains open to availing of those procedures that are available to the parties and to continuing to engage to prevent industrial action from taking place."
Mr Bell said the job evaluation scheme at the centre of the current dispute had identified that the skill level for support staff had increased significantly over a nine-year period.
He said both the Department of Health and the HSE had accepted the findings of the job evaluations, entitling members to pay rises of up to €3,000.
However, he described it as "deeply concerning" that the Department of Public Expenditure and Reform seemed to think they could pay these monies when they chose, and maybe not until the next national public service agreement in 2021.
Mr Bell warned that SIPTU members would not accept another national agreement like the Public Service Stability Agreement unless the current agreement is honoured in full.