[Androide89]

If a man is found after wandering the desert and has sweated excessively he looses hypotonic fluid thus he becomes hypovolemic hypertonic. So wouldn't you treat him with hypotonic fluid to bring his values back to normal. It says in kaplan to treat him with isotonic saline. I was taught to replace the fluid that is lost (ex. hypotonic fluid). Is there any general rule to the type of fluid replacement treatments for these kind of disorders because I keep getting confused? thanks

 

[Seetal]

hi

i just checked the notes, u are right. sweating causes loss of hypotonic fluid. but perhaps giving isotonic fluid is always first choice. when it doesnt work u may give colloids (hypotonic).

im not sure. but yeah i feel the need for isotonic fluid in a dehydrated patient is to ensure the rapid infuse of colloid wont cause him to become hypervolemia n cause other complications (namely renal)

 

[Seetal]

woohooo!!

i found this while trying to answer ur renal O2 query.

Normal (isotonic) saline {0.9%) approximates plasma tonicity (POsm). It is Infused in patients to maintain the blood pressure when there is a significant loss of sodium-containing fluid (e.g., blood loss, diarrhea, sweat). As expected, some ofthe normal saline enters the Interstitial compartment
and some remains in the vascular compartment, the latter being responsible for the increase in blood pressure. Other solutions that are used that are more expensive include Ringer's lactate and 5% albumin (remains in the vascular compartment).

found this in goljan rapid review page 56.

jst to add:

my anesthesiology lecturer reminded us that first-line of treatment should always be isotonic saline, if it doesnt work then u go ahead with colloids. this is because most of the time patients come in with burns, diarrhea n dehydration n we cannot assume they have lost Na until the lab results return.

 

[Androide89]

thanks alot, yeah i think you're right no matter what kind of fluid loss disorder it is you first give isotonic saline to normalize patient's blood pressure than you can give the exact type of fluid they lost (for example in excessive sweating hypotonic fluid) via slow drip IV to normalize osmolarity =)

 

[ashishkabir]

Hmm - okay - so we're saying here that we shouldn't go by "give them what they lost" but instead give them normal saline and the body will adjust?

If it then doesn't adjust, we give them what they're missing? So in this instance after we finish a bag of normal saline, we would find something more hypotonic to give? It'd be great if we could find a flowchart or something like that to follow depending on what situation the patient comes in with...

 

[drmodi44]

our main aim in fluid replacement is to maintain normal BP...for which we need fluid that mostly contribute to Intravascular compartment...

Normal saline is such a fluid...as it is isotonic...if we give hypotonic fluid like .45%saline or 5% dextrose... it will rapidly diffuse in interstitial n intracellular compartment....so less contribution towards intravascular compartment....

better to give NS first..once the pt. is hemodynemically stable...u can correct osmolarity based on etiology....

 

[Seetal]

yes kushboo is rite

basically we have to understand that giving dextrose or a colloid solution might cause the a pulling of fluid from the intracellular space IF the patient doesnt have loss of protein or natrium. so we give NS first., then as soon as lab results are in n looking at ptt's condition, IF needed we infuse dextrose instead. thats what the anesthesiologist said. when in emergency we must think life saving first. n NS does this (even if he lost protein, NS will hold him alive for a bit. better than giving dextrose n cause more damage)

 

[ashishkabir]

That does make sense - keep the volume up first... Thanks for following up guys!