The female patient called 999 but became violent when the crew arrived.
The woman struck out at a member of the crew, hitting her on the face and kicking her. When a second crew member tried to help, she sustained an arm injury.
A spokesperson for the ambulance service said attacks like this are happening on an "almost daily" basis.
In this instance, the spokesperson said, the two ambulance workers were stood down from their shift, which led to reduced cover in the "significantly rural area in and around Enniskillen" from 23:00 BST on Thursday until 08:00 BST on Friday.
Only one crew member remained to cope with calls in the area.
The police were called to deal with the incident.
Two ambulance workers, both women, have been attacked while attending to a patient in Trillick, County Tyrone.