NS480 Unit 3 Energy Needs After Femur Fracture Example

Every Multiplication Shown: A Unit 3 Energy Needs Calculation After a Femoral Shaft Fracture, With a Check on the Stacked Factors

[Student Name]

Purdue University Global

NS480: Medical Nutrition Therapy I

Unit 3 Energy Needs Calculation

[Instructor Name]

[Date]

The patient and his measurements are composite; the predictive equation, the equation review and the nutrition support guideline cited are real.

Patient Data

Raymond is 46. He fractured his right femur in a motorcycle crash and had the bone fixed with an intramedullary rod. On postoperative day 2 he is alert, eating a regular diet, and moving from bed to a bedside chair during two daily therapy sessions. He has no other injuries, no fever and no history of diabetes or kidney disease.

Height: 180 cm, measured on admission. Weight: 88 kg, measured on admission before surgery. Body mass index: 88 divided by 1.80 squared, or 88 divided by 3.24, which is 27.2. His weight is stable by his own report.

Step 1: Resting Energy With Mifflin-St Jeor

The Mifflin-St Jeor equation estimates resting energy expenditure from weight, height, age and sex (Mifflin et al., 1990). In a systematic review of predictive equations, it estimated resting metabolic rate within 10 percent of measured values in more people than the other common equations, in both nonobese and obese adults (Frankenfield et al., 2005). It was developed in healthy people, not in patients after surgery, which matters for the steps that follow.

For men the equation is 10 times weight in kilograms, plus 6.25 times height in centimeters, minus 5 times age in years, plus 5.

1. 10 times 88 equals 880.

2. 6.25 times 180 equals 1,125.

3. 5 times 46 equals 230.

4. 880 plus 1,125 equals 2,005.

5. 2,005 minus 230 equals 1,775.

6. 1,775 plus 5 equals 1,780 kcal per day.

His estimated resting energy expenditure is 1,780 kcal.

Step 2: Applying an Activity Factor

Raymond spends most of the day in bed or a chair, with two therapy sessions. An activity factor of 1.2, commonly used for patients confined to bed with limited movement, is applied.

1,780 times 1.2 equals 2,136 kcal.

Step 3: Applying an Injury Factor

Long-bone fracture and surgery raise energy needs for a period. A factor of 1.25 is applied, within the range often taught for skeletal trauma.

2,136 times 1.25 equals 2,670 kcal.

Step 4: Checking the Stacked Estimate

Two factors multiplied together can inflate an estimate quickly, and the factors themselves come from older studies with wide ranges. As a check, the estimate is compared with a weight-based range. Nutrition support guidance for critically ill adults suggests about 25 to 30 kcal per kilogram per day when indirect calorimetry is not available (McClave et al., 2016). Raymond is not critically ill, so this range is used as an outer check rather than a target.

1. 25 times 88 equals 2,200 kcal.

2. 30 times 88 equals 2,640 kcal.

The stacked estimate of 2,670 kcal sits above even the top of the weight-based range for critically ill patients, which suggests the two factors together have probably overshot the needs of a stable patient eating on a ward.

Step 5: Choosing a Working Estimate

The working estimate is set at 2,300 to 2,400 kcal per day, between the activity-adjusted figure and the stacked figure, and inside the weight-based range. The reasons are that Raymond is mobile, afebrile and eating, so a full trauma factor is unlikely to apply, while bone healing and early rehabilitation do raise needs above simple bed rest. Overfeeding offers no benefit and can raise blood glucose and carbon dioxide production. Underfeeding carries its own risk, slowing wound and bone healing and costing muscle he will need for walking, so the working figure leans toward the middle of the range rather than the bottom.

Step 6: Protein

Protein needs after a fracture are commonly estimated at 1.2 to 1.5 g per kilogram per day to support tissue repair.

1. 1.2 times 88 equals 105.6, or about 106 g.

2. 1.5 times 88 equals 132 g.

The working target is 110 to 130 g of protein per day, spread across three meals and two snacks.

Step 7: Fluid

A common estimate for adults is 30 to 35 mL per kilogram per day. 30 times 88 equals 2,640 mL, and 35 times 88 equals 3,080 mL. The target is about 2,600 to 3,000 mL, adjusted for any changes in his medical status.

Monitoring

Because every step relies on estimates, the plan includes checks. Food intake will be recorded at each meal for three days. Weight will be measured twice a week on the same scale. If he loses more than 2 percent of body weight in a week, or eats less than 75 percent of the target for three days, the estimate and the plan will be revisited. If indirect calorimetry becomes available, it will replace the equations.

Limits of the Calculation

The equation was developed in healthy adults. Activity and injury factors are approximations. Admission weight may include fluid from resuscitation. The final number is a starting point to be adjusted, not a prescription to be followed regardless of what happens.

References

Frankenfield, D., Roth-Yousey, L., & Compher, C. (2005). Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: A systematic review. Journal of the American Dietetic Association, 105(5), 775-789. https://doi.org/10.1016/j.jada.2005.02.005

McClave, S. A., Taylor, B. E., Martindale, R. G., Warren, M. M., Johnson, D. R., Braunschweig, C., McCarthy, M. S., Davanos, E., Rice, T. W., Cresci, G. A., Gervasio, J. M., Sacks, G. S., Roberts, P. R., & Compher, C. (2016). Guidelines for the provision and assessment of nutrition support therapy in the adult critically ill patient. Journal of Parenteral and Enteral Nutrition, 40(2), 159-211. https://doi.org/10.1177/0148607115621863

Mifflin, M. D., St Jeor, S. T., Hill, L. A., Scott, B. J., Daugherty, S. A., & Koh, Y. O. (1990). A new predictive equation for resting energy expenditure in healthy individuals. The American Journal of Clinical Nutrition, 51(2), 241-247. https://doi.org/10.1093/ajcn/51.2.241