anion gap? - 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 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 06-03-2013
USMLE Forums Scout
 
Steps History: Not yet
Posts: 44
Threads: 32
Thanked 0 Times in 0 Posts
Reputation: 10
Default anion gap?

Hi,
If anion gap equation = Na - (Cl + HCO3)
How come the anion gap will INCREASE if we add new acids?
It is supposed that the net anion gap is decreased if we add new acids (as the sum of Cl + HCO3 will increase)
Thanks
Reply With Quote Quick reply to this message



  #2  
Old 06-03-2013
USMLE Forums Addict
 
Steps History: CS Only
Posts: 195
Threads: 28
Thanked 282 Times in 70 Posts
Reputation: 292
Smile

Quote:
Originally Posted by melboghdady View Post
Hi,
If anion gap equation = Na - (Cl + HCO3)
How come the anion gap will INCREASE if we add new acids?
It is supposed that the net anion gap is decreased if we add new acids (as the sum of Cl + HCO3 will increase)
Thanks
Anion gap formula uses measured cations (Na) minus measured anions(cl+hco3). So in metabolic acidosis the acid is an unmeasured cation and when it increases, the measured cations decrease to compensate. Hence a rise in the CALCULATED anion gap.

Note: The actual gap stays the same.

Hope that helps!
Reply With Quote Quick reply to this message
The above post was thanked by:
melboghdady (06-03-2013)
  #3  
Old 06-03-2013
USMLE Forums Addict
 
Steps History: CS Only
Posts: 195
Threads: 28
Thanked 282 Times in 70 Posts
Reputation: 292
Default

Also note in Hyperchloremic Non Anion gap Metabolic acidosis Chloride rises to compensate for a a loss of Bicarb hence there the calculated anion gap stays the same in this case.
Reply With Quote Quick reply to this message
The above post was thanked by:
melboghdady (06-03-2013)



Reply

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
MUDPILES and Normal Anion Gap Acidosis samirde USMLE Step 1 Mnemonics 4 07-25-2011 06:48 AM
Anion gap and non anion gap acidosis Lakshay USMLE Step 2 CK Forum 8 06-10-2011 01:06 PM
Anion gap question INCOGNITO USMLE Step 1 Forum 5 06-07-2011 01:11 PM
can someone please explain anion gap metabolic acidosis? DoctorB USMLE Step 1 Forum 3 03-29-2011 11:31 PM
Anion Gap? lynk USMLE Step 1 Forum 4 06-05-2010 07:59 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)