NUTRITIONAL NEEDS

CALCULATION OF NUTRITIONAL NEEDS

Nutritional needs include the need for energy, the need for protein, and the need for hydration, with vitamins and electrolytes part of the essential requirements.

ENERGY NEEDS

Energy requirements are assessed in a variety of ways. The Harris-Benedict formula has for many years been considered the criterion standard for predicting calorie requirements in acutely ill hospitalized patients, although it may overestimate energy needs.

The formula is outlined in the following sample calculations:

HARRIS-BENEDICT FORMULA

• (Basal energy expenditure [BEE]) X (activity factor) X (injury factor) - BEE is estimated by sex using the following formula:

  • Males: 66.5 + 13.8(wt) + 5.0(ht) - 6.8(age)

  • Females: 655.1 +9.6(wt) + 1.8(ht) - 4.7(age)

• Activity factor

  • Chair- or bedbound – 1.2

  • Out of bed – 1.3

• Injury factor

  • Anabolism – 1.5

  • Burn – 1.5-2.1

  • Cancer – 1.1-1.45

  • Closed head injury – 1.3

  • Elective surgery - 1.0-1.1

  • Fever – 1.2 per 1 degree (>37° C)

  • Major surgery - 1.6

  • Mild infection – 1.2

  • Moderate infection – 1.4

  • Multiple long bone fractures – 1.1-1.3

  • Sepsis – 1.2-1.4

  • Starvation – 0.7

  • Low stress – 1.3

  • Medium stress – 1.5

  • High stress – 2.0

PROTEIN NEEDS

The following factors need to be considered when estimating protein needs:

• Metabolic rate

• Body protein reserves

• Calorie intake

• Nutritional status

• Disease state

• Stress associated with critical illness

• Age

Two ways to determine protein needs based on stress levels follow.

FORMULAS BASED ON STRESS

Blackburn's General Guide for Protein Needs Based on Stress Level

Cerra's Guide for Protein Needs Based on Stress Level

Disease States and Protein Requirements

HYDRATION OR FLUID NEEDS

This must be addressed within each nutritional assessment because it effects lab interpretation and nutritional intervention. Several methods exist to determine fluid requirements.

Fluid Requirements