How to Calculate Enteral Feeding

Enteral feedings are a form of artificial nutrition given to patients who may need bowel rest, cannot feed themselves or are recovering from a surgical procedure on the digestive system. Properly calculating an enteral feeding is vital to the patient's recovery and nutrition. Many forms of enteral feedings are available, which are usually named by the corresponding digestive component they enter. For instance, a naso-gastric feeding is supplied by a tube inserted through the nose down to the stomach; whereas a gastrostomy feeding is administered through a tube inserted directly into the stomach. You must know which type of feeding tube and formula is being used to calculate appropriately.

Instructions

• 1

  Obtain the patient's accurate weight on a medical-grade scale. If required, convert pounds into kilograms by dividing the number of total pounds by 2.2. For instance, 150 pounds divided by 2.2 = 68 kilograms (kg).

• 2

  Estimate the patient's daily caloric, vitamin, protein and other needs. Caloric needs are calculated many ways. One formula is to multiply the patient's body weight in kilograms by a range of 25 to 35 calories for a 24 hour total need. The 68 kg patient x 25 calories = 1700 calorie daily requirement.

• 3

  Factor in the special needs of the patient. For instance, decrease the calories per kilogram to 20, for obese patients -- or choose sugar-free formulas for the diabetic patient. Specialty formulas are available for each age group, as well as special diagnosis, such as renal failure.

• 4

  Look at the calories per milliliter in the ordered formula. Most formulas contains a 1:1 ratio, or one calorie for one milliliter. If the patient requires 1800 calories per day, that equates to 1800 milliliters per day for most commercial formulas.

  Adjust this as necessary, if your formulas concentration varies by dividing the total required calories by the calories per milliliter. For instance, if the formula contains 1.5 calories per milliliter, divide the total number of daily calories by 1.5 to obtain the daily number of milliliters required.

• 5

  Determine the feeding rate in milliliters per hour by dividing the total amount of required milliliers per day by 22 hours. This allows for two hours without feedings, which are used for residual checks, procedures or medication administration. For example, 1800 milliliters per day divided by 22 = 81 ml/hr.

• 6

  Start the enteral feeding at the ordered administration rate. Typically, enteral feedings are initiated between 25 to 50 ml/hr and slowly increased over 4 to 6 hour increments. Check the amount of food left in the stomach -- called a gastric residual -- as ordered, to ascertain if the feeding is being tolerated. A gastric residual greater than 200 ml in the stomach may require stopping the tube feeding.