Easy way to remember ABG's?

This is how I learned it...

ROME:

Respiratory= Opposite:
· pH is high, PCO2 is down (Alkalosis).
· pH is low, PCO2 is up (Acidosis).

Metabolic= Equal:
· pH is high, HCO3 is high (Alkalosis).
· pH is low, HCO3 is low (Acidosis).

HTH,
B.

thank you for that!!!

Wish I had asked last year when we were doing ABGs. I had the hardest time trying to remember. Thanks for sharing!!

This is how I learned it too.

We just went over this today in lecture, and my instructor made it SOOOOO simple.

Draw a grid like a tic-tac-toe board. Label the columns across the top Acid, Normal, and Alkalotic. Down the left side label the rows pH, PaCO2, and HCO3. Fill in the grid....first row is <7.35, 7.35-7.45, and >7.45. Those are values for pH. Then fill in the second row with >45, 35-45, and <35. Those values are for PaCO2. The last row is <22, 22-26, and >26. Those represent HCO3. Okay, now look at your ABG lab report. Say the pH was 7.49, the PaCO2 was 48, and the bicarb was 37. Tie in those values in your grid. You should have 7.49 under alkalotic, 48 under acid, and 37 under alkalotic. Look at the pH first to see if it's acidic, normal, or alkalotic. The next value in the same column will tell you if it's respiratory or metabolic (PaCO2 reflects respiratory, and HCO3 reflects metabolic). It's as simple as which column has two values in it

Acid Normal Alk
_____________________________________
pH <7.35 7.35-7.45 >7.45
_____________________________________
PaCO2 >45 35.45 <35
_____________________________________
HCO3 <22 22-26 >26

Then you can get into whether or not it's compensated

I've attached a "tic-tac-toe" type handout I made for my students when I teach ABG's. Hope this helps

This is the formula I use and it hasn't failed me yet! I thought I would hate ABG's ended up loving them when I learned to tic-tac-toe!

I have an easy way that does NOT rely on remembering which is up and which is down but DOES require a little math.

It is a rule of thumb.

For every 1 millimeter change in the PCO2 the PH will change by .01 in the opposite direction.

So, if the center of normal for PH is 7.40 and the centre of normal for PCO2 is 40 then if your PCO2 rises to 60 you would expect the PH to be 7.2. If it is not then you have some metabolic compensation occuring.