Around 10,000 people whose hospital outpatient appointments were cancelled due to Hurricane Ophelia on Monday may have to wait weeks to get a re-scheduled date.
The cancellations, which were called for safety reasons to prevent public patients having to make journeys in hazardous conditions, could result in extra clinics being laid on in some cases to help clear the backlog, Damien McCallion, the HSE's national director of emergency management, said yesterday.
He said other patients who had appointments with mental health and other services will have to be re-scheduled.
Health services continued to face disruption yesterday, although all outpatient clinics went ahead.
Some waiting list patients awaiting planned surgery had their operations put back because of a lack of beds.
Hospitals were under pressure to free up beds that were occupied by patients who could not be discharged due to the storm.
Mr McCallion said some hospitals opened closed beds and this helped to relieve overcrowding in hospital A&E departments.
The emergency departments were busy in the afternoon as patients, who held off seeking medical care on Monday, attended services yesterday.
Ambulance services in some areas of the country faced difficulties due to fallen trees and road blockages caused by the storm. This led to delays in some cases.
Mr McCallion said homecare services were also disrupted and some patients who needed medical equipment that was powered by electricity had to be moved to community hospitals after electricity supplies were affected.
In the run up to the storm, home care and other staff had tried to visit as many people as possible who rely on home visits in counties which were on "red" alert.
Five hospitals were in areas that suffered electricity blackouts and had to revert to their generators.
The Irish Blood Transfusion Service called for extra blood donations in Dublin to offset the shortfall in supply following the cancellation of all clinics on Monday.
"Cancellation of blood donation clinics on Monday led to a shortfall of approximately 500 donations," said operations director Paul McKinney.
Clinics were back to normal yesterday, with the exception of a scheduled clinic in Donegal which was closed. It will be open today.
"We have some extra bed capacity open in our D'Olier Street and Stillorgan clinics for the rest of the week to help make up the shortfall."
Meanwhile, the Irish Nurses and Midwives Organisation said yesterday it will "not tolerate employers deducting pay or insisting that employees take annual leave as a result of having to stay away from work on Monday due to the hurricane".
David Hughes, deputy general secretary, said: "The decision to declare a red weather warning was to save lives. The Taoiseach himself indicated that he was appealing to private employers to act reasonably where employees adhered to that warning. It is regrettable employers are now seeking to penalise nurses and midwives who adhered to the warning."