ABGs & Acid/Base Imbalance

NUR XXX

ABG

Arterial Blood Gas & Acid-Base Imbalance

Arterial Blood Gas Tests

What is it used for?

What is it?

What does it measure?

Who needs one?

JW Notes: Unless they've learned about ABG tests elsewhere, I'd start with a little description of what they are and why they're done. I'd use Tooltips or Windows to add more info about each of the above questions... I thought this source was useful: https://medlineplus.gov/lab-tests/arterial-blood-gas-abg-test/

JW Notes: Here, I would introduce the pH scale and what it means. Acid => more H+ than OH-; Base => less H+ than OH- probably also introduce (using pop-ups) what causes blook pH to change. For me... I need to know the reasons behind things, so I would be inclined to go as deep as to say "when CO2 disolves in H2O, it creates HCO3- & H+, and the increase in H+ means more acid means lower pH". For mnemonic devices, I'd share that CO2 + water makes carbonic acid, so more acid means lower pH. ...same for the Base side and bicarbonate (but I haven't looked up those specific chemical reactions yet ;)

pH SCALE

The pH Scale

acidosis

alkalosis

+ info

+ info

Why is Acid?

Why is Base?

+ info

+ info

H+ vs OH-

Mechanics of Balance

Respiratory

Metabolic

JW Notes: here is where I'd share some of the information on (original) slides 4 & 5. what the organ does, what the normal ranges are. In pop-ups, I'd probably get into the details of how this mechanism raises/lowers pH.

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VS

Acid/base imbalance matrix

increased pHdecreased CO2

decreased pH increased CO2

Respiratory Acidosis

Respiratory Alkalosis

decreased pHdecreased HCO3

increased pHincreased HCO3

Metabolic Acidosis

Metabolic Alkalosis

pH

Respiratory acidosis

respiratory rate or depth (hypoventilation)

CO2 retention

arterial pCO2

signs & symptoms

treatment modalities

causes

Respiratory alkalosis

respiratory rate or depth (hyperventilation)

"blow off" CO2

arterial pCO2

signs & symptoms

treatment modalities

causes

metabolic acidosis

pH < 7.35 (Normal is 7.35 - 7.45)

HCO3- < 22 (Normal is 22 - 26)

signs & symptoms

treatment modalities

causes

metabolic alkalosis

pH > 7.45 (Normal is 7.35 - 7.45)

HCO3- > 26 (Normal is 22 - 26)

signs & symptoms

treatment modalities

causes