Urine osmolal gap (urinary NH4+ estimate)
Urine osmolal gap (urinary NH4+ estimate) - a deterministic tool in Sophie Well's Clinical Math & Conversions group.
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What this is
Urine osmolal gap (urinary NH4+ estimate) is one of 230 deterministic tools in Sophie Well's Clinical Math & Conversions group. Urine osmolal gap (urinary NH4+ estimate) - a deterministic tool in Sophie Well's Clinical Math & Conversions group.
When to use it
Use this tool when you need a quick, citable reference. Every calculation runs entirely in your browser - no inputs leave your device, no account is required, no AI is involved. The site enforces a strict Content Security Policy and ships no analytics or third-party CDN.
References
Halperin ML, Goldstein MB, Stinebaugh BJ, Jungas RL. The urine osmolal gap: a clue to estimate urine ammonium in "hybrid" types of metabolic acidosis. Clin Invest Med. 1988;11(3):198-202. Read the source ↗
Worked example: Urine osmolal gap 380 mOsm/kg (calculated osm 220; ~NH4+ 190 mEq/L): a wide gap, consistent with intact urinary ammonium excretion (extrarenal cause, e.g. diarrhea).
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