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Thursday, July 25, 2013

More on serious burns



 

Dear Editor:
I read with interest Dr. Koelker's description of burn treatment and had two follow-up questions: why is the issue of fluid replacement at the top of the treatment list, and of such critical importance to a burn victim? What causes the fluid loss that can be fatal?A second question: is it necessary to sterilize any water used before preparing the oral rehydration solution she mentions in the article? Thanks for all you do through SurvivalBlog. Peace to you and yours. - G.R. in Texas

Doc Cindy Replies: Fluid replacement is at the top of the list for several reasons:

1.  Fluid loss is what can kill a person the quickest.
2.  Internal fluid loss is not necessarily apparent, nor is the problem intuitively obvious.
3.  Once kidney damage occurs, it may well be irreversible. 

Other potentially fatal problems set in later.  Lacking gross wound contamination, infection generally takes days to set in.  Hypothermia could occur quickly, but is more easily preventable and is generally reversible.  Burns cause what I usually explain as “internal dehydration.”

People understand dehydration caused by fluid loss or lack of intake, and burns can certainly cause great fluid loss due to constant seepage from the burn.  Of more danger, however, is leakage of fluid from within the blood vessels of the body.  Significant burns cause release of chemicals which cause blood vessels throughout the entire body to become semi-permeable, much like a soaker-hose.  A large amount of fluid can leak out from the blood vessels (the intravascular space) into the space between cells (the extravascular space).  This fluid remains within the body but not the blood vessels and therefore is not useful for maintaining blood flow or blood pressure.  Without sufficient blood flow, the kidneys fail.

On a mechanical note, we could compare this to a closed system that develops an internal leak of, say, lubricating oil or hydraulic pressure.  The fluid may remain within the closed system, but not within the circulating pipes.  Once the pressure drops too low, the system fails, perhaps permanently.  Both “internal” and “regular” dehydration can progress rapidly without proper fluid replacement.  Once kidney failure sets in, without dialysis it is commonly fatal.

As for oral rehydration solution, no, this does not need to be sterile, only appropriate for drinking (potable), whether used orally or rectally.  Normally, oral rehydration solution (water + salt + sugar) would NOT be given intravenously nor via hypodermoclysis.

Todd B., MD comments correctly that it would be difficult to replace fluids completely via hypodermoclysis.  Normally only two sites are used, though perhaps more could be used in a life-threatening emergency.  However, hypodermoclysis does pose an additional problem, that is, the fluid must be absorbed from the extravascular system into the vascular system, and as explained above, the blood vessels become increasingly leaky as time goes on.  This is an additional reason why immediate fluid replacement is so essential.

In today’s world, we think of a single source for fluid replacement, usually intravenous.  In tomorrow’s world, we need to consider multiple potential sources of fluid replacement:  oral, intravenous, hypodermal, rectal.  A combination of methods would likely be necessary with a significant burn.

Can a layperson learn to insert and administer an IV?  I’d say the answer is yes, with careful attention to sterile procedure.  The bigger concern, however, is how much fluid to give, and how quickly, a question I’ll address in a future article. - SurvivalBlog Medical Editor Cynthia J. Koelker, MD

 

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