My mother is diabetic age 80 and had pneumonia. pleural effusion showed pus and few mesenthelial cells and high tlc. no bacteria or fungus was detected in the fluid. doc is recommended for surgical removal of the pockets having fluid. is it safe?

There is no invasive procedure that is completely without risk. You must weight the risks and benefits. If the pockets of fluid are left alone, they may become infected and result in an abscess which can cause a blood infection (sepsis). surgery itself also has risks, including anesthesia reactions, infections, bleeding, etc. Discuss the situation carefully with your mom's Dr.