Understanding ABG's

  1. Hello, I'm new to the world of ITU nursing, in fact i've just finished my 5th shift and am really struggling with understanding ABG's. Can anyone help explain what it all means, please keep it simple
    •  
  2. 20 Comments

  3. by   hrtprncss
    hi there's alot of threads about ABG's if you'd do a search, but here's one link...I'm sure it will help you... http://realnurseed.com/abg.htm scroll down to "Land of ABG's"...hope it helps
  4. by   charlieroe
    Thanx for that link, it's fantastic, really easy to understand!
  5. by   dorimar
    Just remember that CO2 is acid and bicarb is base. CO2 is respiratory and bicarb is metabloic. If they're acidotic, is the CO2 high, or the bicarb low? if they're alkalotic, is the CO2 low or the bicarb high? If they're acidotic, & CO2 is high , it is respiratory acidosis. if they're acidotic and the bicarb is low, then it is metabolic acidosis. If they're alkalotic and the CO2 is low, then it's respiratroy alkalosis. If they're alkalotic and the HCO3 (bicarb) is high, then its metabloic alkalosis. they can be both respiratory & metabolic acidosis, or respiratory and metabloic alkalosis as well. If the pH is heading to nromal or normal with abnomral CO2 or HCO3 then it is compensated.

    Reading this, it sounds as confusing as nursing school makes it. Sorry. It's really simple. Just determine if the'yre acidotic or alkalotic, and then to determine what is causing that, look at the PCo2 and HCO3. PCO2 is respiratory cause. HCO3 is metabolic cause.
    Last edit by dorimar on Oct 17, '05
  6. by   JentheRN05
  7. by   truern
    CharlieRoe, a great online ABG tutorial:

    http://www.maagnursing.com/ABG/index.php

    and this site is very helpful:

    http://www.the-abg-site.com/

    There was also a great thread on allnurses in the last few weeks....you can search for that one

    At www.Ed4Nurses.com they have "6 Easy Steps to ABG Analysis" that was GREAT, but you have to pay to download it. I can't remember offhand what I paid??

    Edited to add: Hi, Jen!! You beat me to it
  8. by   Tiny1Nisolet
    Quote from hrtprncss
    hi there's alot of threads about ABG's if you'd do a search, but here's one link...I'm sure it will help you... http://realnurseed.com/abg.htm scroll down to "Land of ABG's"...hope it helps
    Any suggestions on how to pull this up. I got it this a.m. but I can not get it to load now. I wanted to go over it some more. I thought it was great.
  9. by   zi7027
    thanks for the link to land of ABGs. It has really helped me as a nursing student get a grip of this difficult topic.
  10. by   meandragonbrett
    Check out "Vents and ABGs" at www.icufaqs.org
  11. by   truthtutor
    hi the abg site is a very good site, esp. enjoyed case studies, it informative and very helpful to provide case senarios. ABG's/compensation can be difficult to understand if you are not reguarly working in a critical care setting.
    thanks
  12. by   Burnt2
    Quote from meandragonbrett
    Check out "Vents and ABGs" at www.icufaqs.org
    I second that


    you'll find tons of other helpful info on there as well
  13. by   phiposurde
    Quote from charlieroe
    Hello, I'm new to the world of ITU nursing, in fact i've just finished my 5th shift and am really struggling with understanding ABG's. Can anyone help explain what it all means, please keep it simple
    ****There a technic I saw on a DVD that maybe could help you. It is very simple but don't include everything. As a comparison it would be reading only the rhythm and rate on a 12 lead without Reading all the axis, hemiblock, etcetera. Here goes:
    You woke up one day in a new world. In that world everybody have 3 name: a first name, a middle name and a last name. But you are limited in your choice:
    for first name you can only choose compensated or uncompensated. Middle name respiratory or metabolic and last name acidosis or alkalosis. So you give birth to a baby, in that land baby have ph on the forehead. When they get born you know there first and last name:
    first name, between 7.35-7.45 is compensated otherwise, uncompensated. Then for the last name less then 7.4 acidosis. More then 7.4 Alkalosis. Now you want to know who's the dad of that little one so that you can give him is first name. So you will try to find the dad with the same last name. Remember the other normal CO2:35-45 and HCO3: 22-27/32( in some book). Remember those are text book normal. You have to look the normal with your center. ABG change with altitude.Let do an example:
    ph 7.25 co2: 55 and Hco3: 34
    so our little baby his first name is uncompensated( less then 7,35) and last name acidosis (less then 7.4). Now for his middle name let see who has the same last name. we have the choice between
    Mr. respiratory acidosis( co2 more then 45)
    Mr. metabolic alkalosis.( HCO3 more then 27)
    So the name of our baby is uncompensated respiratory acidosis.

    there an other technique recommended by the ACLS for experienced provider. This one is more complex a little bit. But i find it take in consideration mix metabolic state. It has 6 step:
    1) determine if PH normal( between 7,35-7,45), acidotic or alkalosis
    2)determine if there hypocarbia( CO2 less the 35) or hypercarbia( CO2 more then 45)
    3) 40-Co2( result can be positive or negative)
    4) multiple by 0,008
    5)add to or subs tract from 7,4
    6)if ph greater then the calculated PH there a metabolic alkalosis associated. If it's less ,there a metabolic acidosis associated.
    Example:
    ph 7.30, pco2:80, Po2 58 HCO3:38
    1) acidosis
    2)40-80=-40
    3)-40X .008=-0.32
    4)7,4 - 0.32=7.08
    5)metabolic alkalosis associated
    6)primary resp acidosis with partial metabolic compensation.
    One rule to remember:"compensatory mechanism are unlikely to overcompensate in acid-base abnormalities". Meaning in this case it would be very doubtful that the pt would have retain Co2 to compensate the alkalosis state and therefore transfer to acidosis.

    Hope it help.
  14. by   Sunkyst08
    Thanks so much for that land of ABG's link. That really helps out! i have my respiratory test tomorrow!! 99 days til i graduate!! ) YAAAY!

close