The high coronavirus rate mean's Ireland's health service is battling to keep the levels of care, according to the chief executive.
Paul Reid confirmed there were 650 coronavirus patients receiving some level of critical care on Sunday morning.
Some 214 people with the virus were in intensive care units and a further 436 on advanced respiratory support.
Mr Reid said: "Our teams are battling to hold the levels of care that we value and to save lives. 650 Covid-19 patients are now receiving levels of critical care.
"214 in ICU and 436 on advanced respiratory support. It is not an emergency department crisis now, but it's probably more critical than that."
In total there were 1,914 people in hospital with Covid-19 on Sunday morning.
There were 80 admissions to hospital and 47 discharged in a 24-hour period.
Saturday saw a further 77 deaths and 1,910 new cases of Covid-19 were confirmed by the Department of Health.
It said 76 of these deaths occurred in January, one happened last month.
The median age of those who died was 84 years and the age range was 43 to 98.
Of the new cases, 710 were in Dublin, 150 in Cork, 103 in Meath, 102 in Limerick, 86 in Louth, and the remaining 759 cases are spread across the remaining counties.
Ireland's 14-day incidence rate per 100,000 population is now 955.
The chief medical officer, Dr Tony Holohan, on Saturday said Ireland was starting to flatten the curve thanks to people adhering to public health measures.
"Through the solidarity shown by families and communities across the country in recent weeks, we are beginning to flatten the curve of Covid-19 infection," he said.
"Each individual effort to follow the public health advice is making an impact, but we can only continue this positive trend and drive down incidence in the community by continuing to stay at home and avoid meeting or mixing with others in our social circle."
He urged people to all behave as though they are infectious and minimise close contacts with others. He also stressed that if you do have symptoms it was important to self-isolate immediately.
