Q. I'm a physician that has to be present the night of Yom Kippur at the operation of a patient that may be Jewish. I can't refuse being there since I had already accepted doing it in that afternoon, but the time were changed. I will have to daven that night by myself. Do I say Kol Nidrei? Should I try to find three other people?
A. Horav Shlomo Miller's Shlit'a opinion is that you should try you utmost to be replaced by others, explaining the importance of what keeping Yom Kippur means to you, and that for you it is a practical emergency not to attend.
It it cannot be avoided and you assess that you have to attend because the life of the patient is at risk, you should consult a competent Rabbi as to the details of your attendance.
When you daven later even late at night, you do recite Kol Nidrei by yourself and you do not need the presence of a court of three. You likely already said Hataras Nedarim on the eve of Rosh Hashana.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit'a