Perioperative fluids and electrolytes.
D000223:Adaptation, Psychological; D000367:Age Factors; D000368:Aged; D006801:Humans; D009751:Nutritional Requirements; D011182:Postoperative Care; D011229:Preanesthetic Medication; D011300:Preoperative Care; D014882:Water-Electrolyte Balance; D014883:Water-Electrolyte Imbalance / Q000517:prevention & control