Fluid Replacement; Half or Normal Saline? - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 2 CK Forum

USMLE Step 2 CK Forum USMLE Step 2 CK Discussion Forum: Let's talk about anything related to USMLE Step 2 CK exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 08-24-2012
USMLE Forums Guru
 
Steps History: 1+CK+CS
Posts: 460
Threads: 278
Thanked 166 Times in 81 Posts
Reputation: 176
Question Fluid Replacement; Half or Normal Saline?

Hi all:

In patients who are hypernatremic dehydrated over a period of time, shouldn't we use 0.45% saline to gradually replace the osmolarity?

In kaptest m000826 patients with hypernatremic dehydration and orthostatic hypotension, why do we give normal saline? is it because of " orthostatic hypotension"?

so, when do we give 0.45%saline and when do we give normal saline?

Thank you!
Reply With Quote Quick reply to this message



  #2  
Old 08-24-2012
K06100's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 730
Threads: 90
Thanked 460 Times in 289 Posts
Reputation: 470
Default

me too had this confusion...plzz somebody shed sum light on this......
__________________
Try Not To Become A Man Of Success But A Man Of Value.
Reply With Quote Quick reply to this message
The above post was thanked by:
cingulate.gyrus (08-26-2012)
  #3  
Old 08-24-2012
tyagee's Avatar
USMLE Forums Master
 
Steps History: ---
Posts: 1,365
Threads: 648
Thanked 591 Times in 355 Posts
Reputation: 601
Default

volume deficits are corrected first. and then electrolytes.
if patient vitals are not stable, correct them with normal saline . once vitals are stable, correct electrolyte abn.here by giving half normal saline.
orthostatic hypotension means 15-20 % fluid loss ! and if that was peds q, it means moderate dehydration !
sorry, i dont have any source to cite to.
Reply With Quote Quick reply to this message
The above post was thanked by:
chienpolska (08-26-2012), cingulate.gyrus (08-26-2012), K06100 (08-24-2012)
 
  #4  
Old 08-25-2012
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 623
Threads: 111
Thanked 424 Times in 264 Posts
Reputation: 434
Default

Quote:
Originally Posted by chienpolska View Post
Hi all:

In patients who are hypernatremic dehydrated over a period of time, shouldn't we use 0.45% saline to gradually replace the osmolarity?

In kaptest m000826 patients with hypernatremic dehydration and orthostatic hypotension, why do we give normal saline? is it because of " orthostatic hypotension"?

so, when do we give 0.45%saline and when do we give normal saline?

Thank you!
I think we give normal saline,because as the patient is dehydrated and hypernatremic, so normal saline will be hypotonic as compared to hypertonic plasma,with time by normal saline slowly hypernatremia will be corrected and fluid will start moving into intracellular compartment,hence we can deal with both dehydration and hypernatremia,then we can use 0.45% saline.

I have read it somewhere else.
Reply With Quote Quick reply to this message
  #5  
Old 08-25-2012
Hitman's Avatar
USMLE Forums Master
 
Steps History: Not yet
Posts: 928
Threads: 17
Thanked 539 Times in 375 Posts
Reputation: 549
Default

well i have read in uw that only use normal saline for correction of dehydration and will also correct electrolytes ....dont ever use half normal saline or dextrose as they leave the intravascular system and dont contribute to volume ........ after correcting defects continue on dextrose as maintenance not half normal saline ( its of no use to kids )
Reply With Quote Quick reply to this message
The above post was thanked by:
chienpolska (08-26-2012), cingulate.gyrus (08-26-2012)
  #6  
Old 08-25-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 851
Threads: 88
Thanked 710 Times in 380 Posts
Reputation: 720
Default

choosing between half saline(.45%) and normal saline(.9%) for treatment of hypernatremia .Now to deal with this remember half saline is Hypotonic which will drop the serum saline at very fast pace and risking central pontine myelolysis.
Whereas normal saline is isotonic to plasma and it will bring down sodium at an optimal rate without any risks.
So whenever treating hypernatremia(whichever the cause) always use normal saline which may sound as a hypertonic solution but its not ,its Isotonic to plasma .
__________________
"Don't Forget they need us too"
Reply With Quote Quick reply to this message
The above post was thanked by:
anomali (08-25-2012), chienpolska (08-26-2012), cingulate.gyrus (08-26-2012), salem (08-24-2016), XpaezX (08-26-2012)
  #7  
Old 08-26-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 720
Threads: 217
Thanked 552 Times in 309 Posts
Reputation: 562
Default

Quote:
Originally Posted by step_enhancer View Post
choosing between half saline(.45%) and normal saline(.9%) for treatment of hypernatremia .Now to deal with this remember half saline is Hypotonic which will drop the serum saline at very fast pace and risking central pontine myelolysis.
Whereas normal saline is isotonic to plasma and it will bring down sodium at an optimal rate without any risks.
So whenever treating hypernatremia(whichever the cause) always use normal saline which may sound as a hypertonic solution but its not ,its Isotonic to plasma .
Central pontine myelinolysis occurs with correction of Hyponatremic rapidly..Not for correction of hypernatremia ...
Reply With Quote Quick reply to this message
The above post was thanked by:
step_enhancer (08-26-2012)
  #8  
Old 08-26-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 720
Threads: 217
Thanked 552 Times in 309 Posts
Reputation: 562
Default

In correction of hyponatrimia free water clearence is calculated and corrected over 24 hrs ..NS has 0 free water so how will it correct hypernatremia..

I think the answer is 1/2 NS..
Reply With Quote Quick reply to this message
  #9  
Old 08-26-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 851
Threads: 88
Thanked 710 Times in 380 Posts
Reputation: 720
Default

Quote:
Originally Posted by step_enhancer View Post
choosing between half saline(.45%) and normal saline(.9%) for treatment of hypernatremia .Now to deal with this remember half saline is Hypotonic which will drop the serum saline at very fast pace and risking central pontine myelolysis.
Whereas normal saline is isotonic to plasma and it will bring down sodium at an optimal rate without any risks.
So whenever treating hypernatremia(whichever the cause) always use normal saline which may sound as a hypertonic solution but its not ,its Isotonic to plasma .
I am so sorry ,Huge mistake .If half saline is used to treat hypernatremia it will drop serum sodium at a very fast rate and sodium is exchanged with free water.Further water will flow into brain cells causing them to swell .This can lead to cerebral edema ,potentially resulting in seizures, permanent brain damage, or death.So normal saline is used to prevent rapid correction of hypernatremia

Central pontine myelolysis occurs with Rapid correction of hyponatremia
__________________
"Don't Forget they need us too"
Reply With Quote Quick reply to this message
The above post was thanked by:
cingulate.gyrus (08-26-2012), XpaezX (08-26-2012)
  #10  
Old 08-27-2012
shahzaib123456's Avatar
USMLE Forums Veteran
 
Steps History: 1+CK+CS
Posts: 218
Threads: 4
Thanked 135 Times in 70 Posts
Reputation: 145
Star Normal Saline

Volume deficit (hypovolemia) without a doubt is treated with normal saline.
0.45% saline, or 3% saline are used for electrolyte deficits causing acute signs/symptoms..e.g hyponatremia leading to seizures is treated with 3% saline.
__________________
Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will spend its whole life believing that it is stupid ~Albert Einstein
Reply With Quote Quick reply to this message



Reply

Tags
Electrolytes-

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Fluid Replacement in Pyloric Stenosis! tyagee USMLE Step 2 CK Forum 18 07-02-2012 12:11 PM
IV Fluid Replacement meanmr.mustard USMLE Step 2 CK Forum 3 11-03-2011 10:38 AM
When to give saline and half strenght saline! kemoo USMLE Step 2 CK Forum 0 06-06-2011 09:49 AM
How come normal saline for DKA if Chloride causes metabolic acidosis? Dry815 USMLE Step 1 Forum 2 05-24-2011 11:17 AM
Pay half now, half later on your Step 2 CK Review Course! DrInTraining USMLE Step 2 CK Forum 1 02-22-2011 04:39 AM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)