The normal blood sodium level is 135 to 145 milliequivalents/liter (mEq/L)1. Hypernatremia occurs when the patient’s sodium plasma concentration is higher than the normal range of 135-145 mEq/L. Hypernatremia is uncommon in HD patients, with few cased being reported in the literature, and is often iatrogenic when it occurs2,3. Only a few cases of hypernatremia are reported and these cases are often a result of an error in dialysate composition or conductivity measurement error 4–6. The clinical manifestations of hypernatremia are related to the hyperosmolar effect and subsequent water shift from the intracellular into the extracellular space3.  Hypernatremia may result from lack of water intake, water losses in excess of Na+ losses, or from excess Na+ intake or retention. Hypernatremia can mechanistically be classified as 7 ;

  • Hypovolemic hypernatremia: Reduction in total body water and reduction of total body sodium (fluid loss)
  • Dialysate conductivity can be incorrectly sensed as low by the coated conductivity cells (that gets coated by granules from less soluble batch of sodium bicarbonate powder)1
    • At the start of dialysis if an error is made when connecting concentrate containers
    • Euvolemic hypernatremia: Reduction in total body water; total body sodium is normal (fluid loss)
    • Hypervolemic hypernatremia: Total body water is normal; total body sodium is increased (sodium gain).

Causes of intradialytic hypernatremia include the following:

  • The conductivity monitors of the dialysis machine may not be functioning properly, or the conductivity alarm limits may have not been set properly2.
  • Errors in bicarbonate composition or in acid dialysate concentrate can cause hypernatremia 4–6,8
  • Dialysate conductivity can be incorrectly sensed as low by the coated conductivity cells (that gets coated by granules from less soluble batch of sodium bicarbonate powder) 6,8.

Signs and Symptoms

  • Profound thirst
  • Inter-dialytic weight gain (IDWG)
  • Headache
  • Nausea
  • Vomiting
  • Convulsions
  • Coma
  • Hot flushes
  • Weakness

Recommendations for Correction of Hypernatremia 9,10

If severe acute hypernatremia occurs, the dialysis treatment should be stopped. If the cause of hypernatremia was incorrect dialysate, dialysis should be restarted with corrected dialysate sodium concentrations 4–6. Bhosle et al.4, reported a case of iatrogenic severe hypernatremia due to accidental use of inappropriate bicarbonate concentrate. After correcting the dialysis fluid, HD was restarted, and the serum sodium was restored to normal levels within 48 hours.  Similarly, Sandhu et al. 5, reported that readjustment of volumetric dialysate mixing resulting in the reduction of weight gain and blood pressure in 95 HD patients who received higher dialysate sodium due to an error as a result of change in dialysate concentrate, highlighting the importance of checking delivered dialysate sodium, especially after a change in dialysate concentrate. Whereas,  Williams J et al.6, reported five cases of HD patients who were exposed to hypernatric dialysate due to granular and insoluble bicarbonate powder that was resolved with the use of finer bicarbonate powder packaged in a dry and sealed carton. Obialo et al.2 reported two cases of hypernatremia, that were resolved after replacement or calibration of faulty conductivity meters. Continuous renal replacement therapy is the preferred dialysis modality in patients with chronic hypernatremia11.


As a preventive measure, the conductivity of the dialysate should be measured using an independent conductivity meter prior to initiation of dialysis treatment 12.  Additionally, optimal management of fluid and sodium intake in dialysis patients is an effective measure for the prevention of hypernatremia and maintenance of isonatremia 13.


  1. Mayo Clinic. Hyponatremia. Published online 2020. Available from: https://www.mayoclinic.org/diseases-conditions/hyponatremia/symptoms-causes/syc-20373711#:~:text=A normal blood sodium level,Certain medications.
  2. Obialo C, John S, Bashir K. Iatrogenic hypernatremia in hemodialysis patients: A result of erroneous online conductivity monitor and conducvtivity meter reading. Hemodial Int. 2017;21(4):E73-75. Available from: https://pubmed.ncbi.nlm.nih.gov/28272776/.
  3. Sonani B, Naganathan S A-DM. Hypernatremia. [Updated 2020 Aug 26]. StatPearls [Internet] Treasure Isl StatPearls Publ. Available from: https://www.ncbi.nlm.nih.gov/books/NBK441960/.
  4. Bhosale GP, Shah VR. Successful recovery from iatrogenic severe hypernatremia and severe metabolic acidosis resulting from accidental use of inappropriate bicarbonate concentrate for hemodialysis treatment. Saudi J Kidney Dis Transplant. 2015;26(1):107.
  5. Sandhu E, Crawford C, Davenport A. Weight gains and increased blood pressure in outpatient hemodialysis patients due to change in acid dialysate concentrate supplier. Int J Artif Organs. 2012;35(9):642-647.
  6. Williams DJ, Jugurnauth J, Harding K, Woolfson RG, Mansell MA. Acute hypernatraemia during bicarbonate-buffered haemodialysis. Nephrol Dial Transplant. 1994;9(8):1170-1173. Available from: http://www.ncbi.nlm.nih.gov/pubmed/7800220.
  7. Vadi S, Yim K. Hypernatremia due to Urea-Induced Osmotic Diuresis: Physiology at the Bedside. Indian J Crit care Med peer-reviewed, Off Publ  Indian Soc Crit Care Med. 2018;22(9):664-669.
  8. Davenport A. Complications of hemodialysis treatments due to dialysate contamination and composition errors. Hemodial Int. 2015;19 Suppl 3:S30-3.
  9. Nissenson AR, Fine RN. Clinical Dialysis, Fourth Edition. McGraw-Hill Education; 2005.
  10. Ronco C, Bellomo R, Kellum JA. Critical Care Nephrology. Elsevier Health Sciences; 2008. Available from: https://books.google.com/books?id=MdgvSwnlgRgC&pgis=1.
  11. Tinawi M, Bastani B. A mathematical approach to severe hyponatremia and hypernatremia in renal replacement therapies. Semin Dial. 2021;34(1):42-50.
  12. Pittard JD. Chapter 13 – Safety Monitors in Hemodialysis. In: Nissenson AR, Fine RNBT-H of DT (Fifth E, eds. Elsevier; 2017:162-190.e2. Available from: https://www.sciencedirect.com/science/article/pii/B9780323391542000138.
  13. Canaud B, Kooman J, Selby NM, et al. Sodium and water handling during hemodialysis: new pathophysiologic insights and  management approaches for improving outcomes in end-stage kidney disease. Kidney Int. 2019;95(2):296-309.Semin Dial 3:3-4, 1990

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