If this was a one off incident then the patients should have been terminated by renal tech and told to come back later. I wonder why did they not do it. Or did you as a maintenance engineer not find out how long will it take the power to restore and so could not tell them to take necessary steps.
If it is a regular feature, it is the engineer's (your) responsibility to get the DG/UPS repaired and if required pressurise the management to invest for better equipment. You are not aware how awakening a technical / service report can be if it strongly recommends hazards.
I had an issue relating dialysis machine in a rural area as the quality of water from RO was not good enough. I mentioned in the report 'Any harm to the patient will not be our responsibility till we are satisfied that the RO is repaired and we have seen the lab reports.' Within a week the RO was replaced.
All dialysis machines I saw had atleast a battery backup to keep the blood pump running for minimum 45 mins. This time is sufficient to terminate the procedure.
