In the United States, a voluntary nonsuit is a motion taken by the plaintiff to release one or more of the defendants from liability.
If the plaintiff later settles with the hospital before trial, the resulting nonsuit would end the case as all defendants have been released.
In such circumstances it is functionally equivalent to a motion for a directed verdict or judgment as a matter of law.
[5] A Virginia plaintiff who takes a nonsuit may bring a new action against the same defendant(s) on the same subject matter within six months, regardless of the operation of the Statute of Limitations.
Thereafter it was subsequently ruled that nonsuiting ceased to exist in the High Court of Justice having been wholly displaced by the provisions relating to discontinuance.
This brought nonsuiting to an end in mainstream England and Wales (although one cannot comment for e.g. actions in the High Court of Chivalry).
One therefore presumes nonsuiting no longer exists in Northern Ireland, applying the same principles as in England and Wales.