Which of the following statement(s) is/are true concerning methods of nutritional support?

a. Optimal results for enteral feedings are achieved with approximately half of calories supplied as carbohydrate and half as fat

b. Diarrhea is the most common complication of enteral feeds and is due to the high osmolarity of the carbohydrate components

d. Approximately 25–50% of calories should be provided as fat emulsion in patients receiving total parenteral nutrition

Most formulas for enteral feeding range from 1.0 to 2 cal/ml and include 3 to 7% protein. Most of the calories are supplied as glucose or sucrose, so that the solutions have a very high osmolarity. Cramps or diarrhea can result when these high osmolar solutions are placed into the stomach or intestine. Diarrhea is the major complication with most tube feeding formulas. Diarrhea can be minimized by the use of starch or fat as an energy source in tube feedings. This can be supplied as part of the commercial preparation or added in the form of medium chain triglycerides or other oils. The best results are usually achieved by supplying approximately half the calories as carbohydrate and half as fat. In patients receiving total parenteral nutrition, energy source is provided as carbohydrate, fat, and amino acid solutions. Parenteral feeding with carbohydrate is limited by the sclerotic effect of hyperosmolar solutions on veins. Fat is a more efficient energy source and can be given through peripheral veins in concentrations of either 10 or 20%. Most intensivists favor supplementing standard total parenteral nutrition solution with intravenous fat to provide at least 100 grams of fat emulsion each week to preclude fatty acid deficiency. Giving up to 25 to 50% of calories each day as fat emulsion may optimize the delivery of this caloric delivery.