Medical AINephrology
Cited, interpretable calculators relevant to nephrology. Each tool shows its formula, how to measure every input, the interpretation bands, and the sources it stands on. Editorial navigation, not medical advice.
Calculators in this specialty
The anion gap (sodium minus chloride and bicarbonate) screens for and characterises metabolic acidosis. Because albumin is the main unmeasured anion, a low albumin masks a real gap, so this tool also reports an albumin-corrected value.
The Cockcroft-Gault equation estimates creatinine clearance in mL/min from age, body weight, sex, and serum creatinine. It predates BSA-indexed eGFR equations and is not adjusted to 1.73m2, but it remains the estimate referenced in many drug labels, so it is still used for renal dose adjustment.
About 40% of total calcium is albumin-bound, so a low albumin lowers measured total calcium without changing the physiologically active ionised fraction. This tool adjusts total calcium for albumin in US or SI units. Where accuracy is critical, measure ionised calcium directly.
The 2021 CKD-EPI creatinine equation estimates glomerular filtration rate from serum creatinine, age, and sex, dropping the race coefficient used in earlier versions. The result is reported per 1.73m2 of body surface area and maps onto the KDIGO GFR categories used to stage chronic kidney disease.
FENa is the percentage of filtered sodium that ends up in the urine. In oliguric acute kidney injury a value below 1% points to prerenal azotemia (kidneys avidly reabsorbing sodium in response to hypoperfusion), while a value above 2% suggests intrinsic tubular injury such as acute tubular necrosis. It was derived in selected oliguric patients and is unreliable in several common situations, most notably diuretic use.
Calculated serum osmolality is estimated from sodium, glucose, and urea (BUN). When a measured osmolality is available, the osmolar gap (measured minus calculated) screens for unmeasured osmoles. A large gap with metabolic acidosis raises concern for toxic alcohols (methanol, ethylene glycol).
Winters formula predicts the PaCO2 the lungs should reach to compensate for a primary metabolic acidosis. Comparing the measured PaCO2 against the expected range tells you whether compensation is appropriate or a second respiratory disorder is present.
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01 Educational purpose
Medical AI is an information and reference tool intended for educational use only. The answers it returns are not medical advice, diagnosis, or treatment. Always consult a qualified doctor or healthcare professional with any question concerning a medical condition.
02 Professional use
Medical AI is designed for use by practicing clinicians. It is not intended for direct patient use and is not a substitute for professional clinical judgment. Apply your own training and current guidelines to every decision an answer informs.
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04 Information currency
Medical knowledge evolves rapidly. Citations carry their publication date, so consult the primary source and the most recent clinical guideline before acting on anything material.