{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"corrected-sodium"},"result":{"entity_type":"calculator","id":"corrected-sodium","calculator_id":"corrected-sodium","canonical_url":"https://tttkmbb.com/medical/corrected-sodium","name":"Corrected Sodium Calculator","title":"Corrected Sodium for Hyperglycaemia – Katz (1.6) and Hillier (2.4) Correction Factors","category":"medical","category_name":"Medical & Clinical","tool_name":"calculate_corrected_sodium","featured_mcp_tool":false,"description":"Corrects measured serum sodium for the dilutional effect of hyperglycaemia using the Katz 1.6 mmol/L and Hillier 2.4 mmol/L factors per 100 mg/dL of glucose above 100 mg/dL.","use_when":"A patient has hyperglycaemia (e.g. diabetic ketoacidosis or hyperosmolar state) and you want the sodium that would be measured at a normal glucose.","do_not_use_when":"Glucose is normal (no correction applies) or the hyponatraemia has other causes such as pseudohyponatraemia from lipids or proteins.","inputs":[{"name":"sodium_mmol_l","label":"Measured sodium","type":"number","unit":"mmol/L","required":true,"min":100,"max":200,"description":"Measured serum sodium.","example":130},{"name":"glucose","label":"Glucose","type":"number","required":true,"max":5000,"exclusive_min":0,"description":"Plasma glucose in the unit given by glucose_unit.","example":500},{"name":"glucose_unit","label":"Glucose unit","type":"enum","required":false,"default":"mg_dl","values":[{"value":"mg_dl","label":"mg/dL","aliases":["mg/dl","mgdl"]},{"value":"mmol_l","label":"mmol/L","aliases":["mmol/l","mmol"]}],"description":"Unit of the glucose value (1 mmol/L = 18.016 mg/dL).","example":"mg_dl"}],"outputs":[{"name":"corrected_sodium_katz_mmol_l","label":"Corrected sodium (Katz)","type":"number","unit":"mmol/L","decimals":1,"description":"Sodium + 1.6 per 100 mg/dL glucose above 100."},{"name":"corrected_sodium_hillier_mmol_l","label":"Corrected sodium (Hillier)","type":"number","unit":"mmol/L","decimals":1,"description":"Sodium + 2.4 per 100 mg/dL glucose above 100."},{"name":"glucose_mg_dl","label":"Glucose","type":"number","unit":"mg/dL","decimals":1,"description":"Glucose used in the formula, in mg/dL."},{"name":"correction_katz_mmol_l","label":"Correction applied (Katz)","type":"number","unit":"mmol/L","decimals":1,"description":"Amount added to the measured sodium by the Katz factor."}],"input_schema":{"type":"object","properties":{"sodium_mmol_l":{"description":"Measured serum sodium. Unit: mmol/L.","type":"number","minimum":100,"maximum":200,"examples":[130],"x-unit":"mmol/L"},"glucose":{"description":"Plasma glucose in the unit given by glucose_unit.","type":"number","maximum":5000,"exclusiveMinimum":0,"examples":[500]},"glucose_unit":{"description":"Unit of the glucose value (1 mmol/L = 18.016 mg/dL).","type":"string","enum":["mg_dl","mmol_l"],"default":"mg_dl","examples":["mg_dl"]}},"additionalProperties":false,"required":["sodium_mmol_l","glucose"]},"output_schema":{"type":"object","properties":{"corrected_sodium_katz_mmol_l":{"description":"Sodium + 1.6 per 100 mg/dL glucose above 100. Unit: mmol/L.","type":"number","x-unit":"mmol/L"},"corrected_sodium_hillier_mmol_l":{"description":"Sodium + 2.4 per 100 mg/dL glucose above 100. Unit: mmol/L.","type":"number","x-unit":"mmol/L"},"glucose_mg_dl":{"description":"Glucose used in the formula, in mg/dL. Unit: mg/dL.","type":"number","x-unit":"mg/dL"},"correction_katz_mmol_l":{"description":"Amount added to the measured sodium by the Katz factor. Unit: mmol/L.","type":"number","x-unit":"mmol/L"}}},"formula":"corrected_Na = sodium_mmol_l + factor × (glucose_mg_dl − 100) / 100, with factor 1.6 (Katz) or 2.4 (Hillier); the glucose excess is taken as 0 when glucose ≤ 100 mg/dL; glucose_mg_dl = mmol/L × 18.016","method":"Katz (1973) derived 1.6 theoretically; Hillier (1999) measured 2.4 experimentally and found the effect larger above 400 mg/dL, so both are reported. Results are informational only and not a substitute for clinical judgement or medical advice.","sources":[{"name":"Katz MA (1973) Hyperglycemia-induced hyponatremia – calculation of expected serum sodium depression, N Engl J Med 289:843-844","url":"https://pubmed.ncbi.nlm.nih.gov/4763428/","type":"peer_reviewed","retrieved_at":"2026-09-24"},{"name":"Hillier TA, Abbott RD, Barrett EJ (1999) Hyponatremia: evaluating the correction factor for hyperglycemia, Am J Med 106:399-403","url":"https://www.amjmed.com/article/S0002-9343(99)00055-8/abstract","type":"peer_reviewed","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"Na 130, glucose 500 mg/dL","inputs":{"sodium_mmol_l":130,"glucose":500,"glucose_unit":"mg_dl"},"expected":{"corrected_sodium_katz_mmol_l":136.4,"corrected_sodium_hillier_mmol_l":139.6,"correction_katz_mmol_l":6.4},"url":"https://tttkmbb.com/api/v1/calculate/corrected-sodium?sodium_mmol_l=130&glucose=500&glucose_unit=mg_dl"},{"name":"Na 128, glucose 30 mmol/L","inputs":{"sodium_mmol_l":128,"glucose":30,"glucose_unit":"mmol_l"},"expected":{"corrected_sodium_katz_mmol_l":135.1,"corrected_sodium_hillier_mmol_l":138.6,"glucose_mg_dl":540.5},"url":"https://tttkmbb.com/api/v1/calculate/corrected-sodium?sodium_mmol_l=128&glucose=30&glucose_unit=mmol_l"}],"faq":[{"q":"Which factor should I use?","a":"1.6 is the traditional textbook factor; 2.4 fits experimental data better, particularly when glucose exceeds 400 mg/dL. Reporting both brackets the likely true value."},{"q":"Does the corrected sodium replace the measured value?","a":"No. It estimates what sodium will be once glucose is normalised, which helps judge total-body water and sodium status during treatment."}],"tags":["corrected sodium","hyperglycemia","hyponatremia","dka","sodium correction"],"related":[{"calculator_id":"glucose-unit-conversion","reason":"Convert glucose between mg/dL and mmol/L."},{"calculator_id":"anion-gap","reason":"Assess the acidosis that often accompanies severe hyperglycaemia."}],"links":{"html":"https://tttkmbb.com/medical/corrected-sodium","markdown":"https://tttkmbb.com/medical/corrected-sodium.md","json":"https://tttkmbb.com/medical/corrected-sodium.json","api":"https://tttkmbb.com/api/v1/calculate/corrected-sodium","schema":"https://tttkmbb.com/api/v1/calculators/corrected-sodium","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:48:12Z","next_actions":[{"tool":"run_calculator","calculator_id":"corrected-sodium","reason":"Run Corrected Sodium Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/medical/corrected-sodium.md"}}