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  #1  
Old 07-24-2011
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ER TBW, ICF and ECF

A 42-year-old man attempts to commit suicide by cutting his radial arteries at the wrist. He is brought to the emergency department within 30 minutes and in time to save his life, but he has lost a large volume of blood. Before resuscitation is initiated, which of the following changes to the volumes of total body water (TBW), intracellular fluid (ICF), and extracellular fluid (ECF) will have occurred?

A. TBW decreased, ICF decreased, ECF decreased
B. TBW decreased, ICF decreased, ECF unchanged
C. TBW decreased, ICF unchanged, ECF decreased
D. TBW unchanged, ICF decreased, ECF unchanged
E. TBW unchanged, ICF unchanged, ECF decreased
F. TBW unchanged, ICF unchanged, ECF unchanged
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  #2  
Old 07-24-2011
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Default c?

c) Decrease of ECF decreases TBW; ICF is unchanged....
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  #3  
Old 07-24-2011
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  • Since there's a lot of blood loss the TBW is decreased. (eliminates options D,E,F).
  • Initially his ECF will be decreased as well & ICF will be unchanged.
  • 30 minutes after the injury - His ECF becomes hypertonic & ICF diffuses to ECM to bring it back to normal levels.
  • Ans: TBW- decreased, ICF-decreased, ECF-unchanged. (option B)

This was a good question. I hope I am right! This was one of those questions I wasn't sure of but I worked it out from the method above.
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  #4  
Old 07-24-2011
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c)
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Old 07-24-2011
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c) Blood loss which is iso-osmotic, so ECF decreases, ICF remains the same, TBW decreased cuz ECF is a component of that.
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Old 07-24-2011
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The question above refers to before resuscitation is started ,and within 30 min of bleeding so compensatory mechanisms of redistribution of fluids have not started,and i think it is
C.decreased tbw,unchanged icf,decreased ecf.
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Old 07-24-2011
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Its C. ECF decresed, TBW decreased as well but ICF unchanged, since its a isotonic loss.
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Old 07-24-2011
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hm i was way off lol
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Old 07-24-2011
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C. TBW decreased, ICF unchanged, ECF decreased

Blood loss = isotonic fluid loss
So TBW is decreased
Fluid will shift form interstitial compartment to the vascular volume as the barrier is porus so ECF is decreased due to blood loss. ECF = interstitial compartment volume+ vascular volume
ICF no change as the volume lost is isotonic so there is no shift in fluid
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Old 07-25-2011
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isotonic loss of fluid so the answer is C
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Old 07-25-2011
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I go with c....
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Old 07-25-2011
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ccccccccccccccccccccc
nice question miss
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  #13  
Old 07-25-2011
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Help C.

Its C. .........................................
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Old 07-25-2011
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I'll go with C.
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Old 07-25-2011
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Answer c ICF unchanged
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  #16  
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Search correct answer

The correct answer is C)

Fluid loss without replacement must decrease TBW. Whole blood is lost from plasma. Early capillary refill comes from interstitial fluid. Volume loss is from ECF only, in that no osmotic gradient is developed when losing whole blood to induce water shifts from ICF.
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  #17  
Old 07-25-2011
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Post C

C. TBW decreased, ICF unchanged, ECF decreased
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