{"uid":"cap_wZl4-5hkSRUm3UcrvrMne","slug":"magent-nrpe-natriuretic-response-prediction-equation-rao-2021-83d168b5","name":"Magent NRPE — Natriuretic Response Prediction Equation (Rao 2021)","description":"Rao 2021 natriuretic response prediction equation from caller-assigned eGFR and BSA, serum and urine creatinine, and urine sodium on a spot sample ~2 h after IV loop diuretic. Na_output_mmol = eGFR*(BSA/1.73)*(SerumCr/UrineCr)*60*3.25*(UrineNa/1000). Poor <50 mmol; suboptimal <100 mmol (includes poor); excellent >150 mmol. magent does not compute eGFR or BSA and does not order a diuretic.","url":"https://api.magentlab.com/api/calc/nrpe","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":["egfr_ml_min_1_73m2","bsa_m2","urine_sodium_mmol_l"],"properties":{"bsa_m2":{"type":"number","description":"Caller-assigned body surface area in m² (0.4-3.5). Paper used Du Bois. magent does not compute BSA."},"creatinine_mg_dl":{"type":"number","description":"Serum creatinine in mg/dL (0.1-20). Provide this or creatinine_umol_l, not both."},"creatinine_umol_l":{"type":"number","description":"Serum creatinine in µmol/L (9-1768). Converted as mg/dL = µmol/L / 88.42. Provide this or creatinine_mg_dl, not both."},"egfr_ml_min_1_73m2":{"type":"number","description":"Caller-assigned eGFR in mL/min/1.73m² (5-200). magent does not compute CKD-EPI (including race-based 2009 CKD-EPI)."},"urine_sodium_mmol_l":{"type":"number","description":"Spot urine sodium in mmol/L (1-300), ~2 h after IV loop diuretic."},"urine_creatinine_mg_dl":{"type":"number","description":"Urine creatinine in mg/dL (1-500). Provide this or urine_creatinine_umol_l, not both."},"urine_creatinine_umol_l":{"type":"number","description":"Urine creatinine in µmol/L (88-44210). Converted as mg/dL = µmol/L / 88.42. Provide this or urine_creatinine_mg_dl, not both."}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"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_PXpsuwJJu7Getsu5KLAFw","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 the predicted spot urine sodium output (mmol) ~2 hours after IV loop diuretic using the Rao 2021 natriuretic response prediction equation, and classifies response as poor, suboptimal, or excellent.","exampleAgentPrompt":"My patient has an eGFR of 42 mL/min/1.73m², BSA of 1.85 m², serum creatinine of 1.6 mg/dL, urine creatinine of 95 mg/dL, and a spot urine sodium of 68 mmol/L collected about 2 hours after IV furosemide — use the Rao 2021 natriuretic response equation to tell me if their diuretic response is poor, suboptimal, or excellent.","exampleUseCases":[{"title":"Assessing diuretic response in decompensated heart failure","prompt":"My heart failure patient got IV bumetanide this morning — their eGFR is 35, BSA is 1.92 m², serum creatinine 1.9 mg/dL, urine creatinine 110 mg/dL, and 2-hour spot urine sodium came back at 55 mmol/L. Can you run the Rao NRPE and tell me whether their natriuretic response is poor, suboptimal, or excellent?"},{"title":"Nephrology consult diuretic resistance workup","prompt":"I'm doing a diuretic resistance workup. Patient has eGFR 28, BSA 1.70 m², serum creatinine 2.3 mg/dL, urine creatinine 78 mg/dL, spot urine Na 40 mmol/L drawn 2 hours post-IV loop diuretic. Run the Rao 2021 natriuretic response prediction and give me the calculated Na output in mmol and the response category."},{"title":"Monitoring serial diuretic responses over admission","prompt":"Compare this to yesterday — today's labs 2 hours after IV torsemide: eGFR 50, BSA 2.05 m², serum creatinine 1.2 mg/dL, urine creatinine 145 mg/dL, urine sodium 120 mmol/L. Calculate the Rao 2021 predicted natriuretic response so I can see if we're improving from yesterday's poor response."}],"resultDescription":"Returns the predicted urinary sodium output in mmol using the formula Na_output_mmol = eGFR × (BSA/1.73) × (SerumCr/UrineCr) × 60 × 3.25 × (UrineNa/1000), along with a categorical classification: poor (<50 mmol), suboptimal (<100 mmol, includes poor), or excellent (>150 mmol).","failureModes":["Missing required parameter (eGFR, BSA, or urine sodium) returns validation error","Both serum creatinine units provided simultaneously (mg/dL and µmol/L) causes conflict error","Both urine creatinine units provided simultaneously causes conflict error","Out-of-range values (e.g. eGFR outside 5–200, BSA outside 0.4–3.5) return validation error","Caller-provided eGFR or BSA is incorrect — endpoint does not validate or recompute these values","Urine sample not collected at ~2h post-diuretic will produce a biologically invalid result without error"],"whenToPreferThis":"Use this endpoint when you need to apply the Rao 2021 NRPE formula specifically — i.e., you already have caller-computed eGFR and BSA and want to classify loop diuretic natriuretic response from a 2-hour spot urine sample. Prefer this over generic urine electrolyte tools when the clinical question is diuretic adequacy in the context of heart failure or volume overload management. Do not use this to compute eGFR or BSA — those must be provided by the caller.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T13:10:21.283Z","isFirstParty":false}