eMedicine Specialties > Pediatrics: Cardiac Disease and Critical Care Medicine > Critical Care

Dehydration: Differential Diagnoses & Workup

Author: Lennox H Huang, MD, Associate Chair (Clinical), Assistant Professor, Department of Pediatrics, McMaster University School of Medicine; Interim Chief of Pediatrics, McMaster Children's Hospital
Coauthor(s): Krishnapriya R Anchala, MD, MS, FAAP, Assistant Professor, Department of Pediatrics, Division of Pediatric Emergency Medicine, McMaster University; Dan L Ellsbury, MD, Consulting Staff, Pediatrix Medical Group of Iowa; Consulting Staff, Department of Pediatrics, Neonatology Intensive Care Unit, Mercy Medical Center of Des Moines; Caroline S George, MD, Associate Professor, Consulting Staff, Department of Pediatrics, Division of Critical Care Medicine, University of Minnesota Medical School
Contributor Information and Disclosures

Updated: Nov 3, 2009

Differential Diagnoses

Acidosis, Metabolic
Hypernatremia
Adrenal Insufficiency
Hypochloremic Alkalosis
Alkalosis, Metabolic
Hypoglycemia
Bowel Obstruction in the Newborn
Hypokalemia
Burns, Thermal
Hyponatremia
Congenital Adrenal Hyperplasia
Intestinal Malrotation
Dehydration
Intestinal Volvulus
Diabetes Insipidus
Intussusception
Diabetic Ketoacidosis
Neonatal Sepsis
Diarrhea
Oliguria
Eating Disorder: Anorexia
Pyloric Stenosis, Hypertrophic
Enteroviral Infections
Shock
Fluid, Electrolyte, and Nutrition Management of the Newborn
Shock and Hypotension in the Newborn
Gastroenteritis
Small-Bowel Obstruction
Hyperkalemia

Workup

Laboratory Studies

No definitive laboratory test for dehydration is available. Laboratory data are generally not required if the etiology is apparent and mild-to-moderate dehydration is present.

With severe dehydration, the following laboratory studies are suggested: 

  • Serum sodium should be determined because hyponatremia (<130 mEq/L) and hypernatremia (>150 mEq/L) require specific treatment regimens.
  • Potassium may be elevated (eg, congenital adrenal hyperplasia, renal failure) or low (eg, pyloric stenosis, alkalosis).
  • Chloride may be low in pyloric stenosis (eg, hypochloremic, hypokalemic, or metabolic alkalosis).
  • Poor tissue perfusion in dehydration results in production of lactic acid. Bicarbonate is consumed as lactic acid levels increase. In diabetic ketoacidosis (DKA), ketoacids also consume bicarbonate. Bicarbonate levels can also be reduced because of loss of bicarbonate in diarrheal stools. Low bicarbonate levels have been correlated with increased severity of dehydration in some studies. 
  • Glucose may be dangerously low because of poor intake or extremely elevated in DKA.
  • BUN and creatinine levels may be elevated because of renal hypoperfusion.
  • Urine specific gravity may be elevated in patients with dehydration but should not be relied on because it is not an accurate diagnostic test for dehydration.5 Further caution should be used in the setting of diabetes insipidus, in which the urine is dilute with low specific gravity, even in patients who are dehydrated.
  • Urinalysis may show findings of DKA (eg, ketones, glucose).
  • Electrolyte analysis of any fluid that is lost (eg, urine, stool, gastric fluid) can be performed to further refine the composition of replacement fluids after providing acute fluid resuscitation.

Procedures

  • Intravenous line
    • If severe dehydration is present, peripheral intravenous line insertion may be difficult. The preferred sites for initial insertion attempts include the basilic and cephalic veins in the antecubital fossa and the saphenous veins near the ankle. Transillumination of the insertion site with a fiberoptic light source may be used to facilitate locating the desired vein.
    • If peripheral intravenous access cannot be rapidly achieved (<90 s) in a child with severe dehydration and shock, intraosseous cannulation should be attempted. If the child is not in extremis, more time may be taken to establish central venous access percutaneously (eg, femoral, subclavian, internal, external jugular).
  • Intraosseous line: Intraosseous cannulation can be easily and rapidly achieved in children younger than 6 years. Specially designed intraosseous infusion needles or Jamshidi-type bone marrow aspiration needles may be used. Short large-bore spinal needles may also be used but often bend during placement. The ideal site of insertion is the anteromedial surface of the tibia, 1-3 cm below the anterior tibial tuberosity. Care must be taken to avoid injury to the physeal growth plate.
  • Orogastric/nasogastric tube: An orogastric/nasogastric tube may be inserted to facilitate enteral rehydration in children with mild-to-moderate dehydration. These tubes should be considered to assist in the nutritional recovery of children who are critically ill or severely dehydrated.

More on Dehydration

Overview: Dehydration
Differential Diagnoses & Workup: Dehydration
Treatment & Medication: Dehydration
Follow-up: Dehydration
References
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References

  1. [Guideline] Goldman RD, Friedman JN, Parkin PC. Validation of the clinical dehydration scale for children with acute gastroenteritis. Pediatrics. Sep 2008;122(3):545-9. [Medline].

  2. Steiner MJ, DeWalt DA, Byerley JS. Is this child dehydrated?. JAMA. Jun 9 2004;291(22):2746-54. [Medline].

  3. Colletti JE, Brown KM, Sharieff GQ, Barata IA, Ishimine P. The Management of Children with Gastroenteritis and Dehydration in the Emergency Department. J Emerg Med. Apr 2 2009;[Medline].

  4. Parkin PC, Macarthur C, Khambalia A, Goldman RD, Friedman JN. Clinical and Laboratory Assessment of Dehydration Severity in Children With Acute Gastroenteritis. Clin Pediatr (Phila). Jun 1 2009;[Medline].

  5. Steiner MJ, Nager AL, Wang VJ. Urine specific gravity and other urinary indices: inaccurate tests for dehydration. Pediatr Emerg Care. May 2007;23(5):298-303. [Medline].

  6. Atherly-John YC, Cunningham SJ, Crain EF. A randomized trial of oral vs intravenous rehydration in a pediatric emergency department. Arch Pediatr Adolesc Med. Dec 2002;156(12):1240-3. [Medline].

  7. Hartling L, Bellemare S, Wiebe N, Russell K, Klassen TP, Craig W. Oral versus intravenous rehydration for treating dehydration due to gastroenteritis in children. Cochrane Database Syst Rev. Jul 19 2006;3:CD004390. [Medline].

  8. [Best Evidence] Freedman SB, Adler M, Seshadri R, Powell EC. Oral ondansetron for gastroenteritis in a pediatric emergency department. N Engl J Med. Apr 20 2006;354(16):1698-705. [Medline].

  9. Uhlig U, Pfeil N, Gelbrich G, et al. Dimenhydrinate in children with infectious gastroenteritis: a prospective, RCT. Pediatrics. Oct 2009;124(4):e622-32. [Medline].

  10. Adrogue HJ, Madias NE. Hypernatremia. N Engl J Med. May 18 2000;342(20):1493-9. [Medline].

  11. Bellemare S, Hartling L, Wiebe N, et al. Oral rehydration versus intravenous therapy for treating dehydration due to gastroenteritis in children: a meta-analysis of randomised controlled trials. BMC Med. Apr 15 2004;2:11. [Medline].

  12. Bender BJ, Ozuah PO, Crain EF. Oral rehydration therapy: is anyone drinking?. Pediatr Emerg Care. Sep 2007;23(9):624-6. [Medline].

  13. Bhatnagar S, Bahl R, Sharma PK, et al. Zinc with oral rehydration therapy reduces stool output and duration of diarrhea in hospitalized children: a randomized controlled trial. J Pediatr Gastroenterol Nutr. Jan 2004;38(1):34-40. [Medline].

  14. Choice Study Group. Multicenter, randomized, double-blind clinical trial to evaluate the efficacy and safety of a reduced osmolarity oral rehydration salts solution in children with acute watery diarrhea. Pediatrics. Apr 2001;107(4):613-8. [Medline].

  15. Dale J. Oral rehydration solutions in the management of acute gastroenteritis among children. J Pediatr Health Care. Jul-Aug 2004;18(4):211-2. [Medline].

  16. Duggan C, Fontaine O, Pierce NF, et al. Scientific rationale for a change in the composition of oral rehydration solution. JAMA. Jun 2 2004;291(21):2628-31. [Medline].

  17. Duggan C, Refat M, Hashem M, et al. How valid are clinical signs of dehydration in infants?. J Pediatr Gastroenterol Nutr. Jan 1996;22(1):56-61. [Medline].

  18. Duke T, Molyneux EM. Intravenous fluids for seriously ill children: time to reconsider. Lancet. Oct 18 2003;362(9392):1320-3. [Medline].

  19. Fonseca BK, Holdgate A, Craig JC. Enteral vs intravenous rehydration therapy for children with gastroenteritis: a meta-analysis of randomized controlled trials. Arch Pediatr Adolesc Med. May 2004;158(5):483-90. [Medline].

  20. Gorelick MH, Shaw, KN, Murphy, KO. Validity and reliability of clinical signs in the diagnosis of dehydration in children. Pediatrics. 1997;May;(5):99:E6. [Medline].

  21. Holliday M. The evolution of therapy for dehydration: should deficit therapy still be taught?. Pediatrics. Aug 1996;98(2 Pt 1):171-7. [Medline].

  22. Holliday MA, Friedman AL, Segar WE, et al. Acute hospital-induced hyponatremia in children: a physiologic approach. J Pediatr. Nov 2004;145(5):584-7. [Medline].

  23. Holliday MA, Friedman AL, Wassner SJ. Extracellular fluid restoration in dehydration: a critique of rapid versus slow. Pediatr Nephrol. May 1999;(4):292-7. [Medline].

  24. Hoorn EJ, Geary D, Robb M, et al. Acute hyponatremia related to intravenous fluid administration in hospitalized children: an observational study. Pediatrics. May 2004;113(5):1279-84. [Medline].

  25. King CK, Glass R, Bresee JS, et al. Managing acute gastroenteritis among children: oral rehydration, maintenance, and nutritional therapy. MMWR Recomm Rep. Nov 21 2003;52(RR-16):1-16. [Medline].

  26. Miyasaka K, Shimizu N, Kojima J. Recent trends in pediatric fluid therapy. Methods Find Exp Clin Pharmacol. May 2004;26(4):287-94. [Medline].

  27. Moritz ML, Ayus JC. Preventing neurological complications from dysnatremias in children. Pediatr Nephrol. Aug 4 2005;[Medline].

  28. Moritz ML, Ayus JC. Prevention of hospital-acquired hyponatremia: a case for using isotonic saline. Pediatrics. Feb 2003;111(2):227-30. [Medline].

  29. Moritz ML, Manole MD, Bogen DL, Ayus JC. Breastfeeding-associated hypernatremia: are we missing the diagnosis?. Pediatrics. Sep 2005;116(3):e343-7. [Medline].

  30. Murphy C, Hahn S, Volmink J. Reduced osmolarity oral rehydration solution for treating cholera. Cochrane Database Syst Rev. 2004;CD003754. [Medline].

  31. Nager AL, Wang VJ. Comparison of nasogastric and intravenous methods of rehydration in pediatric patients with acute dehydration. Pediatrics. Apr 2002;109(4):566-72. [Medline].

  32. Nalin DR, Hirschhorn N, Greenough W, et al. Clinical concerns about reduced-osmolarity oral rehydration solution. JAMA. Jun 2 2004;291(21):2632-5. [Medline].

  33. Ozuah PO, Avner JR, Stein RE. Oral rehydration, emergency physicians, and practice parameters: a national survey. Pediatrics. Feb 2002;109(2):259-61. [Medline].

  34. Phin SJ, McCaskill ME, Browne GJ, Lam LT. Clinical pathway using rapid rehydration for children with gastroenteritis. J Paediatr Child Health. Jul 2003;39(5):343-8. [Medline].

  35. Playfor SD. Hypotonic intravenous solutions in children. Expert Opin Drug Saf. Jan 2004;3(1):67-73. [Medline].

  36. Reid SR, Bonadio WA. Outpatient rapid intravenous rehydration to correct dehydration and resolve vomiting in children with acute gastroenteritis. Ann Emerg Med. Sep 1996;28(3):318-23. [Medline].

  37. Santosham M, Keenan EM, Tulloch J, et al. Oral rehydration therapy for diarrhea: an example of reverse transfer of technology. Pediatrics. Nov 1997;100(5):E10. [Medline].

  38. Sarnaik AP, Meert K, Hackbarth R, Fleischmann L. Management of hyponatremic seizures in children with hypertonic saline: a safe and effective strategy. Crit Care Med. 1991;Jun;19(6):758-62. [Medline].

  39. [Best Evidence] Spandorfer PR, Alessandrini EA, Joffe MD, et al. Oral versus intravenous rehydration of moderately dehydrated children: a randomized, controlled trial. Pediatrics. Feb 2005;115(2):295-301. [Medline].

  40. Wathen JE, MacKenzie T, Bothner JP. Usefulness of the serum electrolyte panel in the management of pediatric dehydration treated with intravenously administered fluids. Pediatrics. Nov 2004;114(5):1227-34. [Medline].

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Further Reading

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Keywords

dehydration, negative fluid balance, diarrheal illness, diarrhea, isonatremic dehydration, hypernatremic dehydration, hyponatremic dehydration, end organ failure, cerebral edema, gastroenteritis, cystic fibrosis, diabetes mellitus, treatment, diagnosis

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Contributor Information and Disclosures

Author

Lennox H Huang, MD, Associate Chair (Clinical), Assistant Professor, Department of Pediatrics, McMaster University School of Medicine; Interim Chief of Pediatrics, McMaster Children's Hospital
Lennox H Huang, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Physician Executives, Canadian Medical Association, Ontario Medical Association, and Society of Critical Care Medicine
Disclosure: Nothing to disclose.

Coauthor(s)

Krishnapriya R Anchala, MD, MS, FAAP, Assistant Professor, Department of Pediatrics, Division of Pediatric Emergency Medicine, McMaster University
Krishnapriya R Anchala, MD, MS, FAAP is a member of the following medical societies: American Academy of Pediatrics, Canadian Medical Association, and Ontario Medical Association
Disclosure: Nothing to disclose.

Dan L Ellsbury, MD, Consulting Staff, Pediatrix Medical Group of Iowa; Consulting Staff, Department of Pediatrics, Neonatology Intensive Care Unit, Mercy Medical Center of Des Moines
Dan L Ellsbury, MD is a member of the following medical societies: American Academy of Pediatrics
Disclosure: Nothing to disclose.

Caroline S George, MD, Associate Professor, Consulting Staff, Department of Pediatrics, Division of Critical Care Medicine, University of Minnesota Medical School
Caroline S George, MD is a member of the following medical societies: American Academy of Pediatrics and Society of Critical Care Medicine
Disclosure: Nothing to disclose.

Medical Editor

G Patricia Cantwell, MD, Associate Clinical Professor, Department of Pediatrics, University of Miami; Director of Pediatric Critical Care Medicine, Miller School of Medicine, Jackson Children's Hospital
G Patricia Cantwell, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Emergency Physicians, American Heart Association, American Trauma Society, National Association of EMS Physicians, Society of Critical Care Medicine, and Wilderness Medical Society
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from financial planner; Avanir Pharma Stock Investment from financial planner ; WebMD Salary and stock Employment and investment from financial planner

Managing Editor

Barry J Evans, MD, Assistant Professor of Pediatrics, Temple University Medical School; Director of Pediatric Critical Care and Pulmonology, Associate Chair for Pediatric Education, Temple University Children's Medical Center
Barry J Evans, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Chest Physicians, American Thoracic Society, and Society of Critical Care Medicine
Disclosure: Nothing to disclose.

CME Editor

Mary E Cataletto, MD, Associate Director, Division of Pediatric Pulmonology, Winthrop University Hospital; Professor of Clinical Pediatrics, State University of New York at Stony Brook; Director of Children's Sleep Services, Winthrop University Hospital
Mary E Cataletto, MD is a member of the following medical societies: American Academy of Pediatrics and American College of Chest Physicians
Disclosure: Shering Plough Pharmaceuticals Honoraria Consulting

Chief Editor

Timothy E Corden, MD, Associate Professor of Pediatrics, Co-Director, Policy Core, Injury Research Center, Medical College of Wisconsin; Associate Director, PICU, Children's Hospital of Wisconsin
Timothy E Corden, MD is a member of the following medical societies: American Academy of Pediatrics, Phi Beta Kappa, Society of Critical Care Medicine, and Wisconsin Medical Society
Disclosure: Nothing to disclose.

 
 
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