Acid-Base & Laboratory
Laboratory values frequently need adjusting before they mean what they appear to mean. This group interprets arterial blood gases into a primary acid–base disorder with the reasoning shown step by step, calculates the anion gap with optional correction for hypoalbuminaemia, corrects calcium and phenytoin for a low albumin, derives the absolute neutrophil count from the white cell differential, and computes mean arterial pressure. Reference intervals shown here are conventional values; your own laboratory's ranges take precedence.
Arterial blood gas interpreter
Determine the primary acid–base disorder from pH, pCO₂, and bicarbonate, with a step-by-step account of how the conclusion was reached.
Anion gap
Calculate the serum anion gap, with optional correction for hypoalbuminaemia.
Corrected calcium for albumin
Adjust a total serum calcium for a low albumin, so that the result reflects the physiologically active fraction.
Corrected phenytoin for albumin (Sheiner–Tozer) High-risk
Adjust a total phenytoin concentration for hypoalbuminaemia, with a separate variant for significant renal impairment.
Absolute neutrophil count (ANC)
Calculate the absolute neutrophil count from the white cell count and the percentages of segmented neutrophils and bands.
Mean arterial pressure (MAP)
Calculate mean arterial pressure from systolic and diastolic blood pressure.
High-consequence calculations in this group
These carry a greater risk of harm if the result is wrong or misapplied. Each states its own limits on its page; read them before acting on a number.
- Corrected phenytoin for albumin (Sheiner–Tozer) — Adjust a total phenytoin concentration for hypoalbuminaemia, with a separate variant for significant renal impairment.
Where to go next
- Practice problems — one worked problem for every calculator, solutions hidden until you open them.
- Reference tables and formula sheet — every constant and conversion factor used here, with citations.
- All 58 calculators — the full index, filterable by category.
Other categories
Also known as
ABG · blood gas · acid base · acidosis · alkalosis · pH · pCO2 · bicarbonate · winters · anion gap · AG · metabolic acidosis · MUDPILES · albumin corrected anion gap · corrected calcium · calcium albumin · hypocalcaemia · hypocalcemia · ionised calcium · payne · phenytoin · corrected phenytoin · sheiner tozer · free phenytoin · dilantin · albumin · ANC · absolute neutrophil count · neutropenia · segs · bands · clozapine monitoring · febrile neutropenia · MAP · mean arterial pressure · perfusion pressure · sepsis · vasopressor · blood pressure