Aged Amino Acids--therapeutic use Burns--surgery Cost-Benefit Analysis Enteral Nutrition Glucose--therapeutic use Glutamine--therapeutic use Human Growth Hormone--therapeutic use Humans Muscle, Skeletal--physiology Nitrogen--metabolism Nutritional Support Parenteral Nutrition Parenteral Nutrition, Total Postoperative Care Premedication Proteins--metabolism Surgical Procedures, Operative Treatment Outcome Weight Loss Wound Healing