Electrolytes - urine, Hyponatremia - etiology, Hyponatremia - metabolism, Postoperative Complications - physiopathology, Isotonic Solutions - therapeutic use, Postoperative Complications - etiology, Uterus - surgery, Hyponatremia - physiopathology, Sodium Chloride - therapeutic use, Electrolytes - blood, Postoperative Complications - metabolism