Tips for Respiratory???

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Any tips on how to get this respiratory material down memorized? metabolic/respiratory acidosis/alkalosis?:uhoh3:

Oh geez. I just had a test over this today. I wish I had some good tips but I don't. Good luck!

Specializes in ED.

Remember ROME!

Respiratory Opposite

Metabolic, equal

if your normal values are

pH 7.35 - 7.45

PCO2 35 - 45

HCO3 22 - 26

Let's say your ABGs read:

pH = 7.50 - draw an arrow to the right ---->

PCO2 = 30 - draw an arrow to the left

HCO3 = 26 - that is normal so no arrow

Look at how the arrows are going in opposite directions. The pH of 7.5 tells you it is alkalosis. This gives you respiratory alkalosis. Make sense?

Another one?

pH 7.29

PCO2 = 50 ------>

HCO3 = 26 normal

this is respiratory acidosis because the pH is going acidic.

You try....

pH 7.30

PCO2 42

HCO3 20

you should have metabolic acidosis.

your pH of 7.30

PCO2 42 so ------>

HCO3 20

Make sense? I hope this helps.

meredith

Specializes in ED.

Oh, meant to add that I'm not as good at explaining compensated and uncompensated but I can try that another time if you need that too.

I'm just SPENT tonight and need to refuel my brain cells.

m

Thank you soo much Meredith.....Im trying to put this all together.

Specializes in ER, progressive care.

Always remember ROME = Respiratory Opposite, Metabolic Equal.

In respiratory alkalosis, the pH is increased but the pCO2 level is decreased. See how they are opposite? The same goes for respiratory acidosis. The pH is low but the pCO2 is high.

In metabolic alkalosis, both the pH and the HCO3 levels are high. In metabolic acidosis, the pH and HCO3 levels are both low.

Here are six steps to interpreting ABG's:

1. Look at the pH. Is it low or high?

>7.45 = alkalotic.

2. Look at the pCO2. Normal range is 35-45mm Hg (this is easy because if you know the normal range for pH, which is 7.35-7.45, the numbers for normal pCO2 are also 35-45!)

>45 = acidotic.

3. Look at the HCO3. Normal range is 22-26mEq/L.

>26 = alkalotic.

4. Match up the pCO2 & HCO3 with the pH.

If the pCO2 and pH match (both acidotic or alkalotic), then the acid-base disorder is "respiratory."

If the HCO3 and pH match, then the acid-base disorder is "metabolic."

If the pCO2 and HCO3 are moving in opposite directions (one up and one down) and both show acidosis or alkalosis, then you have a mixed-acid-base problem. (Ex. respiratory acidosis and metabolic alkalosis).

5. Dose the pCO2 & HCO3 go in opposite directions? (ex. one indicates alkalosis and the other indicates acidosis)

If so, then there is compensation.

If the pH is within the normal range of 7.35-7.45, then the compensation is "complete."

If the pH is NOT within the normal range of 7.35-7.45, then compensation is "partial."

6. Evaluate the pO2. Normal range is 80-100mm Hg.

pH: 7.46 ---> alkalotic.

HCO3: 29 ---> alkalotic.

pCO2: 55 -----> acidic.

Here the pH and HCO3 match. This is metabolic alkalosis. Notice how the HCO3 is alkalotic and the pCO2 is aciditic. They are going in opposite directions, therefore there is some compensation going on. Since the pH is out of the normal range, you only have partial compensation. Therefore, you have metabolic alkalosis with partial compensation.

pH: 7.51 ---> alkalotic.

HCO3: 23 (normal)

pCO2: 33 ---> alkalotic.

Here the pH and pCO2 match. This is respiratory alkalosis. Since the HCO3 is normal, you have no compensation.

pH: 7.35 ---> normal.

HCO3: 20 ---> acidic.

pCO2: 29 ---> alkalotic.

The pH is normal. It is within the 7.35-7.45 range. Notice how the HCO3 and pCO2 are going in opposite directions - the HCO3 aciditic and the pCO2 is alkalotic. This indicates compensation. Because the pH is within normal range, you have full compensation. To determine if it is a respiratory or metabolic problem, again look at the pH. It's normal. Look at the pCO2. It is alkalotic. Remember ROME = respiratory opposite. if this was respiratory acidosis, your pCO2 would be HIGH, not LOW. Now look at the HCO3. It is low which is acidotic. In ROME, metabolic is equal. You have a lower pH with a lower HCO3 level. The pH is normal, but it is on the lower end of normal, therefore you have metabolic acidosis with full compensation.

It can be confusing at first, but you just have to keep practicing! And knowing your ranges will really help.

pH: 7.35 - 7.45

pCO2: 35 - 45mm Hg

HCO3: 22 - 26mEq/L

pO2: 80 - 100mm Hg

Hope this helps clarify some confusion!!

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