My father had coronary artery bypass surgery for diabetes and hypertension 2 weeks ago and is still in the intensive care unit. Currently, his white blood cell count is increasing, he has no fever, many tests have been done but no infectious microorganisms have been found, and despite being given strong doses of broad-spectrum antibiotics, he has not responded to antibiotics. I would like to ask why his white blood cell count is high 2 weeks after surgery and how to treat it?