Resting energy expenditure

Equations are available to estimate resting energy expenditure (Table 57-6). The result should be multiplied by a factor to correct for stress or activity level based on clinical judgment. 

The present chapter deals with calculations associated with calories, nitrogen, protein-calorie percentage, parenteral hyperalimentation, and resting energy expenditure (REE) calculations including REE assessments for geriatric and pediatric populations. 

Note The resting energy expenditure (REE) is also referred to as basal energy expenditure and abbreviated as BEE. 

TABLE 11.2. Formulae for Resting Energy Expenditure (REE) Calculations. 

Food intake is one side of the body weight equation energy expenditure is the other. One aspect of energy expenditure is our basal metabolic rate. That is the rate of which we consume energy when at rest. Basal metabolic rates vary significantly from person... 

Table 2.4 Empirical formulae for the calculation of resting energy expenditure of men and women with worked examples Harris Benedict (1919) for adults...

Table 2.7 Percentage increase in resting energy expenditure in trauma, fracture, sepsis, burns or fever...

Table 2.8 Metabolic rate of different organs or tissues in an adult human and contribution of the different organs and tissues to whole-body resting energy expenditure, (REE) in an adult male, female and a six month old child...

The Na ion concentration within the cell is maintained low, due to activity of an enzyme known as the Na+/K+ ATPase. This enzyme/carrier is present in the plasma membrane. It is an antiport system that transports three Na+ ions out of the cell and two K+ ions into the cell, for each molecule of ATP that is hydrolysed (Figure 5.10). It is responsible for maintaining a low Na+ ion concentration but a high K+ ion concentration within the ceU. Its constant activity in many it not all cells requires constant ATP hydrolysis, which accounts for more than 10% of the resting energy expenditure of an adult. 

The quantitative importance of each pathway varies from one tissue to another and from one protein to another. Although hydrolysis of the peptide bonds does not involve ATP, the various processes of protein degradation require considerable expenditure of energy, possibly more than is required for protein synthesis. It is not suprising, therefore, that protein turnover contributes at least 20% to resting energy expenditure (basal metabolic rate). 

MJ - the highest level that has ever been reported. It is Peripheral fatigue about seven times the resting energy expenditure of normal adult males (see Table 2.4). 

A decrease in muscle mass occurs normally during ageing (known as sarcopenia) and decreases resting energy expenditure so that less food is required. 

The resting energy expenditure is almost the same at both 12 and 60 hour starvation (about 310 kJ/hour). 

During the flow phase there is a marked increase in energy expenditure and oxygen consumption. To satisfy this, the cardiac output is increased, from a resting value of about 5 litres per minute, by two fold during mild trauma, or as much as threefold in severe trauma or sepsis. Resistance to blood flow in peripheral arteries decreases, which can lead to... 

Thermic effect of food The production of heat by the body increases as much as thirty percent above the resting level during the digestion and absorption of food. This effect is called the thermic effect of food or diet-induced thermogenesis. Over a 24-hour period, the thermic response to food intake may amount to five to ten percent of the total energy expenditure. 

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