Urine specific gravity as a diagnostic tool for dehydration in children

  • Kalis Joko Purwanto Department of Child Health, Gadjah Mada University Medical School/Dr. Sardjito Hospital, Yogyakarta, Central Java
  • Mohammad Juffrie Department of Child Health, Gadjah Mada University Medical School/Dr. Sardjito Hospital, Yogyakarta, Central Java
  • Djauhar Ismail Department of Child Health, Gadjah Mada University Medical School/Dr. Sardjito Hospital, Yogyakarta, Central Java
Keywords: urine specific gravity, dehydration, refractometer


Background Using clinical judgment to diagnose dehydration can be highly subjective. To diagnose dehydration, it would be ideal to have an accurate, inexpensive, objective and easy-to-perform diagnostic tool. In cases of dehydration, plasma osmolality rises, causing an increase in antidiuretic hormone (ADH) secretion. The increased ADH reduces urine production and increases urine osmolality. Previous studies have show that urine osmolality correlates well to urine specific gravity. We investigated if urine specific gravity can be a reliable and objective detennination of dehydration status.

Objective To assess the accuracy of using urine specific gravity as a diagnostic tool to determine dehydration status of children with diarrhea.

Methods We conducted the study in the pediatric ward of Sardjito Hospital from September 2009 to December 2009. Using a refractometer we measured urine specific gravity from patients with diarrhea. This measurement was then compared to a standard of acute body weight loss, with dehydration defined as weight loss of 5% or more. The cut-off value for defining dehydration using specific gravity measurements was detennined by a receiver-operator curve (ROC).

Results Out of 61 pediatric patients who were recruited in this study, 18 (30%) had dehydration as defined by a body weight loss of 5% or more. Based on the ROC, we determined the cut off  value for urine specific gravity to be 1.022. Using this value, urine specific gravity was 72% sensitive (95% CI 52 to 93), and 84% specific (95% CI 73 to 95) in determining dehydration status.

Conclusion Urine specific gravity is less accurate than clinical judgment in determining dehydration status in children with diarrhea.


1. Wathen JE, MacKenzie T, Bothner JP. Usefulness of the serum electrolyte panel in the management of pediatric dehydration treated with intravenously administered fluids. Pediatrics. 2004;114:1227-34.
2. Indonesian Ministry of Health. Indonesia: Country profile 2007. Jakarta: Center for Data and Information, Indonesian Ministry of Health. 2008.
3. Tambunan SM, Soenarto 55, Juffrie M. Uji diagnostik dehidrasi menurut manajemen terpadu balita sakit [Thesis]. [Yogyakarta]: Gadjah Mada University; 2006.
4. Kahigwa E, Schellenberg D, Schellenberg jA, Aponte J], Alonso PL, Menendez C. Inter-observer variation in the assessment of clinical signs in sick Tanzanian. Trans R Soc Trop Med Hyg. 2002;96:162-6.
5. World Health Organization. Management of severe malnutrition: a manual for physicians and other senior health workers. Geneva: World Health Organization; 1999.
6. Bhattacharya SK. Therapeutic methods for diarrhea in children. World J Gastroenterol. 2000;6:497-500.
7. GuytonAC, Hall jE. Text book of medical physiology. 9th ed. Philadelphia: WB Saunders Company; 1996; p. 439-47.
8. Rowe MI, Lloyd DA, Lee M. Is the refractometer specific gravity a reliable index for pediatric fluid management? J Pediatr Surg. 1986;21:580-2.
9. Leech 5, Penney MD. Correlation of specific gravity and osmolality of urine in neonates and adults. Arch Dis Child. 1987;62:671-3.
10. Benitez OA, Benitez M, Stijnen T, Boot W, Berger HM. Inaccuracy in neonatal measurement of urine concentration with a refractometer. J Pediatr. 1986;184:613-6.
11. Stuempfle KJ, Drury DG. Comparison of three methods to assess urine specific gravity in collegiate wrestlers. J Athl Train. 200 3;38:315-9.
12. Chadha V, Garg U, Alon US. Measurement of urinary concentration: a critical appraisal of methodologies. Pediatr Nephrol. 2001;16:374-82.
13. Vasquez 5, Mueller S. Refractometer calibration, use and maintenance. USA (CA): University of California Cooperative Extension Fresno County; 2001.
14. Teach SJ, Yates EW, Feld LG. Laboratory predictors of fluid deficit in acutely dehydrated children. Clin Pediatr.1997;36:395-400.
15. 5u 5B, Lin KH, Chang HY, Lee CW, Lu CW, Guo HR. Using urine specific gravity to evaluate the hydration status of workers working in an ultra-low humidity environment. J Occup Health. 2006;48:284-289.
How to Cite
Purwanto K, Juffrie M, Ismail D. Urine specific gravity as a diagnostic tool for dehydration in children. PI [Internet]. 30Oct.2010 [cited 1Mar.2024];50(5):269-3. Available from: https://paediatricaindonesiana.org/index.php/paediatrica-indonesiana/article/view/996
Received 2016-11-01
Accepted 2016-11-01
Published 2010-10-30