If a person loses consciousness during the month of Ramadan, they must observe as many qaza fasts as the number of days they remained unconscious.
If the person loses consciousness during the day, after making the intention to fast, it is not mandatory to perform qaza for that day’s fast as the fast is considered valid because the intention was made.
However, if they lose consciousness before making the intention to fast, they must perform qaza for that day’s fast as well.