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Workflow Playbook
Connect ABG acid-base interpretation with oxygenation, cardiac output, and vascular resistance calculations for structured clinical checking.
Hubs
Begin with the ABG rather than with a single alarming number. Confirm pH, PaCO2, bicarbonate, base excess, temperature, and units. Use bicarbonate-pH conversion when a value must be cross-checked, then calculate the anion gap and compare the observed compensation with Winter's formula. A mismatch can suggest a mixed disorder, but the result still needs clinical correlation.
When oxygenation is the question, document FiO2 and barometric assumptions before using the alveolar gas equation. The A-a gradient compares alveolar and arterial oxygen, while the P/F ratio summarizes PaO2 relative to FiO2. Oxygen content adds hemoglobin and saturation context; dead-space and shunt estimates require their own assumptions and should not be treated as interchangeable severity scores.
Fick cardiac output depends on oxygen consumption and arterial-venous oxygen content difference. Cardiac index adjusts flow for body surface area, while stroke volume, ejection fraction, and rate-pressure product answer different questions. Mean arterial pressure, SVR, and PVR are meaningful only when pressure, flow, and unit conventions are explicit.
These calculators support education and checking. They do not replace clinician judgment, direct measurement, or decisions about diagnosis and treatment.
Workflow playbook
Convert pH and bicarbonate if needed, calculate anion gap, and use base excess and Winter's formula to check metabolic and respiratory compensation.
Estimate alveolar gas and ventilation, then compare arterial oxygen using the A-a gradient, P/F ratio, oxygen content, dead-space fraction, or shunt equation as supported by the data.
Calculate Fick cardiac output when oxygen consumption and content data are available, then derive index, stroke volume, ejection fraction, or rate-pressure product from appropriate inputs.
Record mean arterial pressure and calculate systemic or pulmonary vascular resistance only with the corresponding flow, pressure, and unit conventions documented.
Start with pH, PaCO2, and bicarbonate or base excess; then assess alveolar oxygen, A-a difference, P/F ratio, content, dead space, or shunt when oxygenation is the question.
Use Fick data for cardiac output, stroke volume and heart rate for cardiac index, or blood pressure and resistance inputs for SVR and PVR.
A calculated abnormality may reflect assumptions, timing, unit errors, or poor measurements, so do not interpret it in isolation.