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E: WATER |
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Water is an
essential element for survival and a deficiency leads to a multitude
of complications. |
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Daily Fluid replacement is essential |
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Water is a very
essential nutrient, as water is required to transport nutrients and
remove by products from cell metabolism in addition to its effect on
maintaining cardiovascular stability.
Dehydration is a
major problem in patients with a stress response due to increased
evaporative losses. Dehydration is also a major problem with
established malnutrition due to both lack of intake and increased
losses, especially in the elderly due to the inability of aging
kidneys to concentrate urine. These problems combined with a
decrease in thirst sensation result in inadequate hydration. In
addition, more water is needed to process and excrete the necessary
increased calorie and protein intake.
Recommendations
of daily fluid intake are based on caloric intake as well as
replacement of losses. Optimum macronutrient intake in the absence
of inadequate fluid will lead to poor nutrient processing and can
accentuate the degree of dehydration. |
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Water requirements per nutrient intake = 1cc of water per calorie |
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What is the
Importance of Providing Adequate Hydration with Nutrient? |
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Maintain adequate intra-cellular
volume required for cell metabolism. |
Maintain adequate extra-cellular
volume required needed for:
- Transport of O2 and nutrients
to the cell
- Transport of urea and
by-products away from the cell
- Adequate clearance of these
by-products by the kidney
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Having discussed optimum nutrient and micronutrient
support, it is now essentially the importance of maintaining
hydration be addressed. Inadequate hydration will impeded support
by impairing intracellular metabolism as cell volume decreases.
In addition an adequate extra cellular volume is required
for transport of oxygen to the cell and move metabolites away from
the cell.
In addition
metabolites must be excreted which requires adequate renal
clearance. Dehydration impedes renal function. |
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The Problem of Post Burn Water Loss
- Loss of skin integrity
produces a massive loss of water from the wound surface (till
wound closure).
- Hypermetabolism increases
urinary output (water losses) 2 to 3 fold above normal.
- Gastrointestinal losses can be
severe with the presence of diarrhea.
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What are the Fluid (water) Losses
after Burn
- Water loss increases with
wound exposure.
- Increases with increase in
temperature (10% per degree).
- Peaks at eschar separation (2
- 4 liters/day - adult major burn).
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Estimated Surface Water Loss: ml/hr = (25 + %TBS Burn x M2 body
weight) |
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70 kg patient 50% TBS = 3 liter water loss/day |
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Must Add Free Water to keep up with the Losses |
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Treatment: Replace
as free water |
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Decrease Loss by:
Wound Occlusion Dressing (50%) |
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Wound Closure:
Graft, Substitute (80%) |
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Status of Bodily Fluid Water Balance |
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Adequate |
Inadequate |
Excess |
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Urine spec gravity
1.010 - 1.020 |
Urine spec gravity>1.020 Hyperosmolar
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Urine spec gravity>1.010 Hyperosmolar
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Normosmolar state |
Hypernatremia |
Hypernatremia |
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Good turgor non-skinned burn |
Decreased
turgor |
Increasing edema |
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