{"uid":"cap_N32Q0LicrSxJef3AgZ81j","slug":"serum-anion-gap-calculator-emmett-narins-1977-d7cb6f9b","name":"Serum Anion Gap Calculator (Emmett–Narins 1977)","description":"Serum anion gap from sodium, chloride, and bicarbonate, with or without potassium. formula=without_k or formula=with_k is required; magent does not pick one. Deterministic Emmett–Narins 1977 arithmetic with citation. Not a diagnosis, albumin-corrected gap (Figge/Fencl), or delta gap.","url":"https://api.magentlab.com/api/calc/anion_gap","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET","HEAD","DELETE"],"type":"string"},"headers":{"type":"object","additionalProperties":{"type":"string"}},"queryParams":{"type":"object","required":["sodium_mmol_l","chloride_mmol_l","bicarbonate_mmol_l","formula"],"properties":{"formula":{"enum":["without_k","with_k"],"type":"string","description":"without_k (Na - Cl - HCO3) or with_k (Na + K - Cl - HCO3). Required; magent does not pick one silently."},"sodium_mmol_l":{"type":"number","description":"Serum sodium in mmol/L (110-160)."},"chloride_mmol_l":{"type":"number","description":"Serum chloride in mmol/L (70-130)."},"potassium_mmol_l":{"type":"number","description":"Serum potassium in mmol/L (1.5-8.0). Required when formula=with_k. Ignored when formula=without_k."},"bicarbonate_mmol_l":{"type":"number","description":"Serum bicarbonate in mmol/L (2-45)."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":{"type":"json","example":{"path":"/api/calc/anion_gap","count":2,"items":[{"formula":"without_k","citation":{"id":"emmett-narins-1977","doi":"10.1097/00005792-197701000-00002","title":"Clinical use of the anion gap","source":"Medicine (Baltimore). 1977;56(1):38-54","authors":"Emmett M, Narins RG"},"disclaimer":"Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.","sodium_mmol_l":140,"chloride_mmol_l":104,"anion_gap_mmol_l":12,"bicarbonate_mmol_l":24,"formula_expression":"anion_gap_mmol_l = sodium_mmol_l - chloride_mmol_l - bicarbonate_mmol_l"},{"formula":"without_k","citation":{"id":"emmett-narins-1977","doi":"10.1097/00005792-197701000-00002","title":"Clinical use of the anion gap","source":"Medicine (Baltimore). 1977;56(1):38-54","authors":"Emmett M, Narins RG"},"disclaimer":"Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.","sodium_mmol_l":140,"chloride_mmol_l":104,"anion_gap_mmol_l":12,"bicarbonate_mmol_l":24,"formula_expression":"anion_gap_mmol_l = sodium_mmol_l - chloride_mmol_l - bicarbonate_mmol_l"}]}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.005","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.005/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.005","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_1zI_aXIGeVGdqNBriZStq","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.005","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Computes serum anion gap from sodium, chloride, and bicarbonate (with optional potassium) using the Emmett–Narins 1977 formula, returning a deterministic arithmetic result with citation.","exampleAgentPrompt":"Calculate the serum anion gap without potassium using the Emmett–Narins formula for a patient with sodium 138 mmol/L, chloride 100 mmol/L, and bicarbonate 22 mmol/L.","exampleUseCases":[{"title":"Metabolic acidosis workup in the ED","prompt":"My patient in the ER has Na 142, Cl 104, bicarb 18 — can you calculate the standard anion gap without potassium using the Emmett–Narins formula?"},{"title":"ICU electrolyte panel with potassium","prompt":"Run the anion gap with potassium included for an ICU patient: sodium 135, potassium 5.2, chloride 99, bicarbonate 20 mmol/L — use the with_k formula."},{"title":"Automated EMR lab result enrichment","prompt":"For every basic metabolic panel result coming in, calculate the serum anion gap without potassium — Na is 140, Cl is 105, HCO3 is 25 mmol/L — and include the citation for the formula used."}],"resultDescription":"Returns the calculated anion gap value in mmol/L, the formula variant applied (without_k: Na − Cl − HCO3, or with_k: Na + K − Cl − HCO3), and a citation to Emmett & Narins 1977. Does not produce a diagnosis, albumin-corrected gap, or delta gap.","failureModes":["Missing required formula parameter — endpoint requires explicit formula=without_k or formula=with_k","Missing potassium when formula=with_k is specified","Sodium, chloride, or bicarbonate values outside accepted physiological ranges (Na 110–160, Cl 70–130, HCO3 2–45 mmol/L)","Potassium out of range (1.5–8.0 mmol/L) when with_k formula is used","Payment failure (x402) if USDC balance is insufficient"],"whenToPreferThis":"Use this endpoint when you need a deterministic, cited serum anion gap computation from raw electrolyte values and want explicit formula selection (with or without potassium). Prefer it over manual calculation when auditability and citation are important, or when embedding anion gap logic into a clinical decision pipeline. Do not use it if you need albumin-corrected (Figge/Fencl) gap, delta gap, or a diagnostic interpretation — this endpoint returns arithmetic only.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T01:14:15.049Z","isFirstParty":false}