We are facing some dilemma with a patient and would like to ask for your advice: a 75 year old woman, hypertensive , diabetic, scheduled for an elective knee arthroplasty . She uses at home Hydralazyne, Olmesartan, vidagliptin, rosuvastatin and hydrochlorotiazide. She has a history of splenectomy some years ago, but she doesn`t know why. She thinks it is because she had a "low white blood cell count", as she explains. Her lab exams show 500.000 platelets and Na= 127mEq/l. Renal function ok. Otherwise normal except for glucose 138. The question is: should we continue with elective surgery? Should the Na be corrected before surgery? What would be the lowest safe sodium limit for an elective procedure?