9. Six Steps for Acid-Base Analysis Step 1. Is there an acidemia or alkalemia?
10. Six Steps for Acid-Base Analysis Step 2. Is the primary process metabolic or respiratory?
11. Six Steps for Acid-Base Analysis Step 3: If the primary process is respiratory, is it acute or chronic?
12. Six Steps for Acid-Base Analysis Step 4: Is there an anion gap? Na + - Cl - - HCO 3 - > 12?
13. Six Steps for Acid-Base Analysis Step 5: Is the respiratory compensation adequate? Expected pCO 2 range = [1.5(measured HCO 3 - )]+8+/- 2
14. Six Steps for Acid-Base Analysis Step 6: Are there any other metabolic disturbances? Corrected HCO 3 - = (Measured HCO 3 - ) + (AG-12)
15.
16. Six Steps for Acid-Base Analysis Step 1. Is there an acidemia or alkalemia? Acidemia
17. Six Steps for Acid-Base Analysis Step 2. Is the primary process metabolic or respiratory? pCO 2 = 10 should drive pH ↑ HCO 3 - = 5 should drive pH ↓
18. Six Steps for Acid-Base Analysis Step 3: If the primary process is respiratory, is it acute or chronic? Skip this step as primary process is metabolic!
19. Six Steps for Acid-Base Analysis Step 4: Is there an anion gap? Na + - Cl - - HCO 3 - > 12? 123 - 99 - 5 = 19 Anion Gap Metabolic Acidosis
20.
21. Six Steps for Acid-Base Analysis Step 5: Is the respiratory compensation adequate? Expected pCO 2 range = [1.5(measured HCO 3 - )]+8+/- 2 [1.5 (5) +8] +/- 2 = [13.5 – 17.5] pCO 2 = 10, therefore it IS a respiratory alkalosis
22. Six Steps for Acid-Base Analysis Step 6: Are there any other metabolic disturbances? Corrected HCO 3 - = (Measured HCO 3 - ) + (AG-12) (5) + (19-12) = 12 Since this does not correct bicarbonate back to normal, there is a non anion gap acidosis
23.
24.
25.
26. Six Steps for Acid-Base Analysis Step 1. Is there an acidemia or alkalemia? Acidemia
27. Six Steps for Acid-Base Analysis Step 2. Is the primary process metabolic or respiratory? pCO 2 = 25 should drive pH ↑ HCO 3 - = 10 should drive pH ↓
28. Six Steps for Acid-Base Analysis Step 3: If the primary process is respiratory, is it acute or chronic? Skip this step as primary process is metabolic!
29. Six Steps for Acid-Base Analysis Step 4: Is there an anion gap? Na + - Cl - - HCO 3 - > 12? 130 - 80 - 10 = 40!! Anion Gap Metabolic Acidosis
30. Six Steps for Acid-Base Analysis Step 5: Is the respiratory compensation adequate? Expected pCO 2 range = [1.5(measured HCO 3 - )]+8+/- 2 [1.5 (10) +8] +/- 2 = [21 - 25] pCO 2 = 25, therefore this is normal respiratory compensation
31. Six Steps for Acid-Base Analysis Step 6: Are there any other metabolic disturbances? Corrected HCO 3 - = (Measured HCO 3 - ) + (AG-12) (10) + (40-12) = 38 Since this over corrects bicarbonate there is a metabolic ALKALOSIS!!
32.
33. Six Steps for Acid-Base Analysis Step 1. Is there an acidemia or alkalemia? Acidemia
34. Six Steps for Acid-Base Analysis Step 2. Is the primary process metabolic or respiratory? pCO 2 = 28 should drive pH ↑ HCO 3 - = 8 should drive pH ↓
35. Six Steps for Acid-Base Analysis Step 3: If the primary process is respiratory, is it acute or chronic? Skip this step as primary process is metabolic!
36. Six Steps for Acid-Base Analysis Step 4: Is there an anion gap? Na + - Cl - - HCO 3 - > 12? 125 - 100 - 8 = 17 Anion Gap Metabolic Acidosis
37. Six Steps for Acid-Base Analysis Step 5: Is the respiratory compensation adequate? Expected pCO 2 range = [1.5(measured HCO 3 - )]+8+/- 2 [1.5 (8) +8] +/- 2 = [18-22] pCO 2 = 28, therefore this is a respiratory acidosis even though the value is below 40!!
38. Six Steps for Acid-Base Analysis Step 6: Are there any other metabolic disturbances? Corrected HCO 3 - = (Measured HCO 3 - ) + (AG-12) (8) + (17-12) = 13 Since this is below the normal range after correction, there is a non anion gap acidosis
39. If data doesn’t make sense, check the validity of your data! 24 (pCO 2 )/(HCO 3 - ) = [H + ] 80 – [H + ] = xx xx should equal the last two digits of the pH. 7. xx