Clinical assessment and diagnosis of hypovolemia (dehydration) in children
- Michael J Somers, MD
Michael J Somers, MD
- Associate Professor of Pediatrics
- Harvard Medical School
Fluid therapy is intended to maintain the normal volume and composition of body fluids, and, if needed, to correct any existing abnormalities. In children, the most common abnormality is hypovolemia.
Volume depletion reduces the effective circulating volume (ECV), compromising tissue and organ perfusion. If severe hypovolemia is not corrected in a timely fashion, ischemic end-organ damage occurs leading to serious morbidity, and, in patients in shock, death. (See "Hypovolemic shock in children: Initial evaluation and management".)
The clinical assessment and diagnosis of hypovolemia will be reviewed here. Repletion therapy for hypovolemia is discussed elsewhere. (See "Treatment of hypovolemia (dehydration) in children".)
Volume depletion occurs when fluid is lost from the extracellular space at a rate that exceeds intake. The most common sites for extracellular fluid loss are:
●Gastrointestinal tract (eg, diarrhea, vomiting, bleeding)
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- Risk factors
- VOLUME DEPLETION VERSUS DEHYDRATION
- CLINICAL ASSESSMENT
- Degree of hypovolemia
- Type of fluid lost
- LABORATORY TESTING
- Serum sodium
- - Secretion of ADH
- - Prior fluid replacement
- Serum potassium
- Serum bicarbonate
- Urine sodium
- Urine osmolality and specific gravity
- INFORMATION FOR PATIENTS
- SUMMARY AND RECOMMENDATIONS