Thank you for your query.
I am sorry to learn about the turn of events and the death of your sister. I shall try to address all your concerns:
1. Following cardiac surgery
sudden death can occur due to arrhythmias (electrical malfunction of the cariac tissue). However the extent of the pocket of pus shall have to considered too.
2. Blood reports can be normal and do not tell the extent of infection.
3. In superficial pockets of pus the method of removing the pus was correct. Yes, it is a painful procedure.
4. Negligence on the part of doctors is a debatable issue. Infection post surgery is a big issue with the medical fraternity and there are a number of causes for it. Unfortunately it is not possible to enumerate them here.
I hope I have answered your query to your satisfaction.
Rajiv K Khandelwal