ABG Interpretation & Practice

Most ABG interpretation apps name the disorder and stop. This one shows the work — and then checks it. Updated for 2027.

Type pH, PaCO2 and HCO3 and you get the answer named, with the ROME walk-through that got there, one row at a time. Then the app does the part the free calculators leave out: it runs the published expected-compensation formulas — Winter's and its three siblings — against your numbers and says whether the response is the size the primary disorder predicts, or whether a second, concurrent disorder is hiding underneath. Then drill graded cases until the pattern is automatic.

Built for respiratory-therapy and nursing students who have to read an arterial blood gas on an exam and on a floor. No subscription; bought once.

INTERPRET
- The full answer in plain words: "Partially compensated respiratory acidosis," "Fully compensated metabolic alkalosis," and the rest.
- A colour-coded read on each value — red for acid, blue for base — so you can see which one is driving the pH.
- A pH-spectrum bar that marks where your pH sits against 7.35, 7.40, and 7.45.
- The ROME walk-through, one row at a time: pH, then PaCO2, then HCO3, then the primary disorder, then the compensation — the reasoning, not just the label.
- Expected compensation: the range the primary disorder predicts for the responding value, drawn as a band with your measurement marked on it, and the formula it came from printed underneath — Winter's formula for a metabolic acidosis, the published bedside rules for the other three. When your value falls outside the band, the app names the concurrent disorder that would explain it. This is the check that separates a truly compensated gas from a mixed one.
- Every gas you interpret is kept in Recent, on your device — a worksheet you can tap back into. Copy the whole interpretation as text.

DRILL
- Practice endlessly or take a scored test of 5, 10, 20, or 30 cases.
- Read the values, pick the interpretation from four options, and get immediate feedback with the full breakdown.
- Score, streak, best streak, and average time per case, with a graded results screen and a private on-device history.
- Accuracy over time: one point for every day you drill, so you can see yourself getting faster and surer.
- Missed cases come back in a review deck until you get them right.

HONEST BY DESIGN
- A normal pH with opposing abnormal values is read as full compensation, and the app tells you plainly that the same numbers can also mean a mixed disorder. The expected-compensation check narrows that question with the published formula; the clinical picture is what finally settles it, and the app says so.
- The compensation check runs on the Interpret tab only. Practice cases are generated to ROME labels rather than to the expected-compensation bands, so running the check on them would teach from numbers that were never built for it. The Guide says this in as many words.
- Values that can't fit any pattern are flagged "re-check your entry," never force-labelled.
- Every rule, range and formula is standard, published material, cited in the in-app Guide (StatPearls; Berend et al., NEJM 2014; Brandis, Acid-Base Physiology §9.3; the ROME method).

This is student study and exam-prep software, not clinical decision support. It classifies the numbers you enter using textbook rules — it does not diagnose, does not know your patient, and must never be used to guide real care. Always follow your program, your institution's protocols, and a qualified clinician's judgment. Verify every result independently.

- One-time purchase. No subscription, no ads, no in-app purchases.
- Works fully offline. No account, no analytics, no advertising, and no network requests of any kind. Nothing you enter leaves your device.

NCLEX is a registered trademark of NCSBN. This app is not affiliated with or endorsed by NCSBN.