I'm gonna teach you the easiest way I've ever learned---been a labor nurse for 3 years and learned this just last week. All you care about are these numbers- 10--60--12 in regards to
pH--PCo2--HCo3 respectively. If the pH is above 7.10 you don't care about the gas because it's a normal value- you can call it normal and move on with your life. If the pH is below 7.10, you move on to the next two numbers. If the pH is below 7.10 and the PCo2 is above 60, you know there is a respiratory component but you want to rule out mixed acidosis so you need to look at the HCo3. If its below 12, it's normal so you know you have respiratory acidosis. If pH is below 7.10, PCo2 is below 60 but HCo3 is above 12 what do you have? Metabolic acidosis. And finally of pH is below 7.10, PCo2 is above 60 and HCo3 is above 12, you have Mixed acidosis. I hope this helps. You can PM me if you need more clarification.