Advertisement

Hourly variation in urine (Na+K) in chronic hyponatremia related to SIADH: Clinical implication

      Dilute urine may be considered to have an isotonic portion and an electrolyte-free water portion. The proportions of electrolytes-free water and isotonic can be measured by the ratio of effective solutes (principally sodium and potassium, with associated anions) between the plasma and the urine [
      • Furst H.
      • Hallows K.R.
      • Post J.
      • Chen S.
      • Kotzker W.
      • Goldfarb S.
      • et al.
      The urine plasma electrolyte ration: a predictive guide to water restriction.
      ,
      • Grant P.
      • Ayuk J.
      • Bouloux P.M.
      • Cohen M.
      • Cranston I.
      • Murray R.D.
      • Rees A.
      • Thatcher N.
      • Grossman A.
      The diagnosis and management of inpatient hyponatremia and SIADH.
      ]. Restriction of water intake to less than the amount of electrolyte-free water excreted will cause serum sodium to rise.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to European Journal of Internal Medicine
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Furst H.
        • Hallows K.R.
        • Post J.
        • Chen S.
        • Kotzker W.
        • Goldfarb S.
        • et al.
        The urine plasma electrolyte ration: a predictive guide to water restriction.
        Am J Med Sci. 2000; 319: 240-244
        • Grant P.
        • Ayuk J.
        • Bouloux P.M.
        • Cohen M.
        • Cranston I.
        • Murray R.D.
        • Rees A.
        • Thatcher N.
        • Grossman A.
        The diagnosis and management of inpatient hyponatremia and SIADH.
        Eur J Clin Invest. 2015; 45: 888-894
        • Winzeler P.
        • Lengsfeld S.
        • Nigro N.
        • et al.
        Predictors of non-response to fluid restriction in hyponatremia due to the syndrome of inappropriate antidiuresis.
        J Intern Med. 2016; 280: 609-617
        • Cuesta M.
        • Ortola A.
        • Garrahy A.
        • Calle Pascual A.L.
        • Runkle I.
        • Thompson C.J.
        Predictor of failure to respond to fluid restriction in SIADH in clinical practice; time to re-evaluate clinical guidelines.
        Q J Med. 2017; 110: 489-492
        • Decaux G.
        • Mush W.
        Estimated daily urine volume and solute excretion from spot urine samples to guide the therapy of hyponatremia in SIADH.
        J Clin Med. 2019; 8: 1511
        • Bell G.M.
        • Atlas S.A.
        • Pecker M.
        • Sealey J.E.
        • James G.
        • Laragh J.H.
        Diurnal and postural variations in plasma atrial natriuretic factor, plasma guanosine 3’:5’-cyclic monophosphate and sodium excretion.
        Clin Sci. 1990; 79: 371-376
        • Decaux G.
        The syndrome of inappropriate secretion of antidiuretic hormona (SIADH).
        Sem Nephrol. 2009; 29: 239-256
        • Musch W.
        • Thimpont J.
        • Vandervelde D.
        • et al.
        Combined fractional excretion of sodium and urea better predicts response to saline in hyponatremia than also usual clinical and biochemical parameters.
        Am J Med. 1995; 99: 348-355
        • Musch W.
        • Decaux G.
        Utility and limitations of biochemical parameters in the evaluation of hyponatremia in the elderly.
        Intern Urol Neprhol. 2001; 32: 475-493
        • Decaux G.
        • Gankam Kengne F.
        • Couturier B.
        • Musch W.
        • Soupart A.
        • Vandergheynst F.
        Mild water restriction with or without urea for the longrerm treatment of SIADH: can urine osmolality help the choice?.
        Eur J Intern Med. 2018; 48: 89-93