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*
Hypermetabolism: an increase in Energy
Utilization
*
Severe Catabolism: rapid
erosion of Lean Mass, critical to body structure
and function
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The
metabolic abnormalities will be discussed first beginning
with the fundamentals, then expand the knowledge base.
The
first fundamental problem is a persistent increase in
body metabolism or hypermetabolism which increases
energy utilization thereby increasing energy demand.
The
second problem is severe catabolism or tissue
breakdown and protein degradation. The lean body mass
compartment contains the body protein is eroded which means
loss of muscle, visceral protein, collagen and proteins
required for organ structure and
cell function.
Metabolism
and Burn Injury (Key Definitions)
ENERGY: CAPACITY
TO DO
WORK
ENERGY
PRODUCTION:
defined in terms of standard ENERGY
units produced per time, or OXYGEN
CONSUMED per time
as O2
is used to make ENERGY
ENERGY
CONSUMPTION
- energy used/time (e.g.. Kcal/hr or ml O2/min)
KILOCALORIE
- standard measure of the quantity of ENERGY
obtained from nutrients (often referred to as a Calorie)
(e.g. One gram Carbohydrate
produces 3.3 Kcal)
KEY
DEFINITIONS
In
order to proceed further we need to understand the terminology
used in describing metabolism. The term energy simply means
the capacity to do work. In terms of the body any activity or
cell function requires work or energy to perform.
Energy
production
is a term used to quantify the
amount of energy generated over time. Since 95% of the oxygen
used is for energy production, oxygen consumed can also be
used as a measure of energy as can the Kilocalorie (Calorie).
Energy
consumed
again quantifies the energy used. Energy consumed, in the form
of oxygen used or Calories burned is used to determine the
patients nutrient requirements.
A
Kilocalorie
is
the measure of energy used to describe the available energy in
specific nutrients when metabolized. Different nutrients
contain different
quantities of potential energy.
When discussing calories, required in nutritional support, one
is still dealing with the fundamental concept of energy.
Calorie
is a term used interchangeably with Kcal.
Key
Definitions
METABOLISM:
Sum (body) total of all
chemical reactions required for cell function - an energy
requiring process
METABOLIC
RATE: rate of metabolic
activity defined in terms of energy consumed per time (e.g.
Kcal/hr)
BASAL
METABOLIC RATE: amount
of ENERGY expended at complete rest (available in standard
charts) age, sex, size dependent
HYPERMETABOLISM:
increase in metabolic
rate above normal for a
specific activity level
ANABOLISM:
Constructive Metabolism:
new tissue formation with protein synthesis.
CATABOLISM:
Destructive
Metabolism: tissue degradation with protein breakdown
  
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