Enter a blood gas and this page walks you to the acid-base disorder step by step. It uses the ROME trick. Respiratory means pH and CO₂ move Opposite ways. Metabolic means pH and HCO₃ move Equal, that is, the same way. Load a practice case with one tap.
Enter the values
Type in any ABG, or load a practice case. Normal values: pH 7.35–7.45 · CO₂ 35–45 · HCO₃ 22–26.
7.35–7.45
35–45 mmHg
22–26 mEq/L
pH
7.40
Normal
CO₂ · Respiratory
40
Normal
HCO₃ · Metabolic
24
Normal
How to read it with ROME: first decide if the pH is acidotic (<7.35) or alkalotic (>7.45). Then check which number moved which way. If the CO₂ moved the opposite way to the pH, one up and one down, the problem is Respiratory. That is the O in ROME. If the HCO₃ moved the same way as the pH, both up or both down, the problem is Metabolic. That is the E. If the other number has shifted too, that shift is compensation.
Interpretation
Two organs set the pH. The lungs hold the CO₂ weight, which is acid. The kidneys hold the HCO₃ weight, which is base. The beam below tips toward whichever side is heavier, and the arrow on the scale shows where the pH lands.