Article    Table of Contents                    Articles citing this article  Services    Send comment/rapid response letter    Notify a friend about this article    Alert me when this article is cited    Add to Personal Archive    Download to Citation Manager    ACP Search                            Get Permissions  Google Scholar    Search for Related Content  PubMed Articles in PubMed by Author:    Ayus, J. C.    Arieff, A. I.    Related Articles in PubMed    PubMed Citation    PubMed

LETTER

Postoperative Hyponatremia

J. Carlos Ayus, MD, and Allen I. Arieff, MD

15 June 1997 | Volume 126 Issue 12 | Page 1005

---

TO THE EDITOR:

We read with interest the study by Steele and colleagues [1] suggesting that near-isotonic fluid infusion could decrease the plasma sodium level in postoperative patients. They have thus confirmed that the phenomenon in which volume expansion in persons with elevated plasma antidiuretic hormone levels results in a substantial quantity of infused NaCl excreted in the urine [2] also applies to persons who have just had surgery. However, these findings should not suggest that infusion of isotonic (154 mmol of NaCl per L) can lead to postoperative hyponatremic encephalopathy. Among 158 postoperative patients with hyponatremic encephalopathy studied at our laboratory and 31 additional patients described between 1935 and 1990, not 1 patient was given isotonic NaCl [3]. Three were given Ringer lactate solution (130 mmol of sodium per L).

Steele and colleagues showed a mean decline in plasma sodium level of only 4 mmol/L, not a dangerous level [1]. Of note, all patients in this study who developed fatal hyponatremic encephalopathy received hypotonic fluid after surgery. The authors have confirmed our previous finding that brain damage from postoperative hyponatremic encephalopathy occurs primarily in women of childbearing age, particularly after gynecologic surgery [4]. Equally important, however, is the fact that these authors have confirmed that in this susceptible population, plasma sodium levels as high as 126 mmol/L can be fatal. It should be pointed out that hyponatremic encephalopathy may occur not only when the hypotonic fluid is administered intravenously but also when it is absorbed by way of the uterine lining during endoscopy-assisted vaginal hysterectomy [5]. In summary, although administration of near-isotonic fluid may lead to a modest decrease in plasma sodium level, clinicians should be aware that the routine use of hypotonic fluids in postoperative patients should be avoided.

Author and Article Information

Top Author & Article Info References

Baylor College of Medicine, Houston, TX 77030
University of California Medical Center, San Francisco, CA 94122

References

Top Author & Article Info References

1. Steele A, Gowrishankar M, Abrahamson S, Mazer CD, Feldman RD, Halperin ML. Postoperative hyponatremia despite near-isotonic saline infusion: a phenomenon of desalination. Ann Intern Med. 1997; 126:20-5.

2. Nolph KD, Schrier RW. Sodium, potassium, and water metabolism in the syndrome of inappropriate antidiuresis. Annu Rev Med. 1980; 31:315-27.

3. Ayus JC, Arieff AI. Brain damage and postoperative hyponatremia: role of gender. Neurology. 1996; 46:323-8.

4. Ayus JC, Wheeler JM, Arieff AI. Postoperative hyponatremic encephalopathy in menstruant women. Ann Intern Med. 1992; 117:891-7.

5. Ayus JC, Arieff AI. Glycine-induced hypoosmolar hyponatremia. Arch Intern Med. 1997; 157:223-6.

About Letters

The Editors welcome submissions for possible publication in the Letters section. Authors of letters should:

•Include no more than 300 words of text, three authors, and five references

•Type with double-spacing

•Send three copies of the letter, an authors' form signed by all authors, and a cover letter describing any conflicts of interest related to the contents of the letter.

Letters commenting on an Annals article will be considered if they are received within 6 weeks of the time the article was published. Only some of the letters received can be published. Published letters are edited and may be shortened; tables and figures are included only selectively. Authors will be notified that the letter has been received. If the letter is selected for publication, the author will be notified about 3 weeks before the publication date. Unpublished letters cannot be returned.

Annals welcomes electronically submitted letters.

This article has been cited by other articles:

				R Guerrero, A Pumar, A Soto, M A Pomares, S Palma, M A Mangas, A Leal, and F Villamil Early hyponatraemia after pituitary surgery: cerebral salt-wasting syndrome Eur. J. Endocrinol., June 1, 2007; 156(6): 611 - 616. [Abstract] [Full Text] [PDF]

				R. M. Belin, B. C. Astor, N. R. Powe, and P. W. Ladenson Smoke Exposure Is Associated with a Lower Prevalence of Serum Thyroid Autoantibodies and Thyrotropin Concentration Elevation and a Higher Prevalence of Mild Thyrotropin Concentration Suppression in the Third National Health and Nutrition Examination Survey (NHANES III) J. Clin. Endocrinol. Metab., December 1, 2004; 89(12): 6077 - 6086. [Abstract] [Full Text] [PDF]

				D Taylor and A Durward Pouring salt on troubled waters Arch. Dis. Child., May 1, 2004; 89(5): 411 - 414. [Full Text] [PDF]

Article    Table of Contents                    Articles citing this article  Services    Send comment/rapid response letter    Notify a friend about this article    Alert me when this article is cited    Add to Personal Archive    Download to Citation Manager    ACP Search                            Get Permissions  Google Scholar    Search for Related Content  PubMed Articles in PubMed by Author:    Ayus, J. C.    Arieff, A. I.    Related Articles in PubMed    PubMed Citation    PubMed