ABGs and EKGs

Daytonite, BSN, RN · Mar 30, 2009

the weblinks with the tutorials on how to analyze abgs are on post #45 of this sticky thread: https://allnurses.com/nursing-student-assistance/pathophysiology-p-microbiology-145201.html - pathophysiology/ a & p/ microbiology/ fluid & electrolyte resources. the weblinks with tutorials for ekg analysis are on post #39 of this sticky thread: https://allnurses.com/nursing-student-assistance/any-good-iv-127657.html - any good iv therapy or nursing procedure web sites.

JGarner37 · Mar 30, 2009

I have also had trouble w/ interpreting EKG's & am still working on that.

The first thing I can tell you for ABG's is know your values.

When given a problem, first look at the pH. Is it acidosis or alkalosis

Then look at the PCO2: is it high or low

Then look at the HCO3: is it high or low

I draw arrows next to the each factor (whether high or low) & then compare my arrows. Follow ROME (Respiratory Opposite Metabolic Equal) meaning in respiratory (acidosis or alkalosis) the pH arrow will be in the opposite direction of the PCO2. If it is metabolic (acidosis or alkalosis), the pH arrow will be the same direction as the HCO3. If either is partially compensated the other value will be off. If it is fully compensated, the pH will be normal and the others will be off. But, even though the pH is within normal limits, you can still tell if it's acidosis or alkalosis. If it's higher than 7.4 (7.41+), it's alkalosis, if it's lower than 7.4, it's acidosis. Then follow the previous steps.

http://www.skillstat.com/Flash/ECGSim531.html

http://www.nhlbi.nih.gov/health/dci/diseases/hhw/hhw_electrical.html

Good luck!

Daytonite, BSN, RN · Mar 30, 2009

http://www.nhlbi.nih.gov/health/dci/diseases/hhw/hhw_electrical.html

This is an inactive link.

JGarner37 · Mar 30, 2009

http://www.nhlbi.nih.gov/health/dci/Diseases/hhw/hhw_electrical.html

This is a little clip of the electrical conduction of the heart & how it relates to the ECG.

ShortStackRN · Mar 30, 2009

Thank you for the info! I'm only having trouble with compensation and partial compensation with ABGs so hopefully some of these will help!

JGarner37 · Mar 31, 2009

If it is fully compensated, the pH will have returned to a normal limit (7.35-7.45) but the other values will be abnormal. For example:

pH: 7.43

PaCO2: 48

HCO3: 36

1) assess the pH. It is normal but >7.40 so it is on the high side of neutral (since it is above 7.40), indicating alkalosis (for this purpose) ↑

2) Assess the PaCO2: it is high ↑

3) Assess the HCO3: It is high ↑

4) follow ROME (respiratory opposite, metabolic equal). Look at your arrows. Since the arrows are going the same direction (equal), we know it is metabolic.

Dx: Fully compensated metabolic alkalosis

____

Partial compensation is only partially compensated because the pH is not back into normal range yet, but the body is working to get it there. In partially compensated, the pH is still outside of the range, & the both of the other values will be off (which indicates partial compensation) because in a regular imbalance, the pH will be off & only one of the other values will be off. In partially compensated, again all 3 are off.

Ex:

pH: 7.33

paCO2: 62

HCO3: 35

Step 1: assess the pH. It is low ↓ (indicating acidosis)

step 2: assess the PaCO2: it is high ↑

step 3: Assess the HCO3: it is high ↑

step 4: look at your arrows & follow ROME. We know it is respiratory because the arrows are opposite (pH v. others). We know that it is partially compensated d/t all of the values being off & we know it is acidosis d/t the low pH.

Dx: Partially comensated respiratory acidosis.

Normally I don't rsepond to these things.. but, I used to have a really hard time w/ this stuff & am hoping I can simplify this. Again, you HAVE to know your values. If you don't know your values, you cannot interpret an ABG. If you still don't get it after reading this & have some time before an exam, buy Fluid & electrolytes made incredibly easy. When I started nursing school, I would guess on these questions because I didn't even know where to start. Now, several semesters after I read the book (now taking critical care) - I still understand it. It helped me a lot. The other thing is once you figure out the steps, practice! If you need clarification on this, let me know. Good luck!