Severe hypovolemia must be treated rapidly with intravenous (IV) boluses of isotonic saline Once circulating volume is adequate, further treatment of hypovolemia will depend on the serum sodium Overly rapid correction of hypo- or hypernatremia can lead to serious central nervous system (CNS) complications Treatment of severe hyperkalemia is aimed at stabilizing the myocardium to prevent arrhythmias and enhancing movement of potassium into the intracellular space Metabolic acidosis is primarily treated by attempting to correct the underlying cause Acute kidney injury (AKI) may lead to severe fluid and electrolyte disturbances that require emergent intervention regardless of the underlying etiology The management of many causes of AKI is supportive in nature Nephrotic syndrome is often steroid responsive in children Chronic kidney disease (CKD) may go unrecognized prior to presentation to the ED RELATED CHAPTERS Signs and Symptoms Abdominal Distension: Chapter 12 Coma: Chapter 17 Dehydration: Chapter 22 Diarrhea: Chapter 23 Edema: Chapter 25 Hematuria: Chapter 36 Hypertension: Chapter 37 Pain: Abdomen: Chapter 53 Pain: Back: Chapter 54 Pain: Dysuria: Chapter 57 Rash: Papulosquamous Eruptions and Viral Exanthems: Chapter 70 Respiratory Distress: Chapter 71 Seizures: Chapter 72 Urinary Frequency: Chapter 78 Vomiting: Chapter 81 Weakness: Chapter 82 Weight Loss: Chapter 83 Dermatologic Urgencies and Emergencies: Chapter 88 Medical, Surgical, and Trauma Emergencies Endocrine Emergencies: Chapter 89 Gastrointestinal Emergencies: Chapter 91 Hematologic Emergencies: Chapter 93 Metabolic Emergencies: Chapter 95 Rheumatologic Emergencies: Chapter 101 Abdominal Trauma: Chapter 103 Genitourinary Trauma: Chapter 108 Genitourinary Emergencies: Chapter 119 Transplantation Emergencies: Chapter 125 DEHYDRATION/HYPOVOLEMIA CLINICAL PEARLS AND PITFALLS Oral rehydration is the treatment of choice for mild to moderate dehydration In moderate to severe hypovolemia, isotonic crystalloid should be given IV in 20 mL/kg boluses until intravascular volume has been restored Subsequent volume repletion strategies will be determined by serum sodium levels Current Evidence Volume depletion occurs frequently in children and is a common finding in patients presenting to the ED Hypovolemia refers to a decrease in the effective circulating volume, which can occur with salt and water loss or water loss alone By definition, the term dehydration refers to water loss alone, but the terms hypovolemia and dehydration have been used interchangeably in the clinical literature Children are at greater risk for hypovolemia than adults due to several factors: gastroenteritis with significant volume loss occurs at a higher frequency in children; children have a higher surface area-to-volume ratio resulting in greater insensible losses; and children may be less able to access adequate fluids to replenish losses given their developmental limitations Goals of Treatment Hypovolemia leads to a reduction in the effective circulating volume, which may compromise tissue and organ perfusion Significant hypovolemia must be recognized and corrected rapidly in order to prevent hypoperfusion and ischemic end organ damage and progression to hypovolemic shock, which is associated with significant morbidity and mortality Fluid therapy is aimed at correcting existing abnormalities and maintaining normal volume and composition of body fluids Hypovolemia may be associated with other electrolyte abnormalities or acid–base disturbances Specific treatment will depend on associated abnormalities, particularly hyponatremia or hypernatremia Clinical Considerations Clinical recognition Concern for volume depletion should be raised in any patient presenting to the ED with a history of increased fluid losses or poor oral intake Young children or children with developmental delay may also be at increased risk due to inability to communicate their needs and lack of access to fluid intake in response to thirst Triage considerations Children with a history or appearance suggestive of hypovolemia should be assessed in a timely manner to evaluate their degree of hypovolemia and potential need for rapid intervention While oral rehydration therapy (ORT) may be appropriate for mild to moderate dehydration, children with severe hypovolemia require rapid resuscitation with IV isotonic crystalloid Clinical assessment The initial assessment of a child with hypovolemia should include a medical history and thorough physical examination A careful history should establish the cause of hypovolemia, duration of illness, and approximate volume and composition of fluid taken in as well as urine output Potential causes of increased insensible losses, such as fever and tachypnea, should be considered The physical assessment should include an accurate weight A change in weight from a recent healthy baseline, if available, would provide the most accurate objective account of the degree of depletion Assessment of intravascular volume should include the pulse quality and rate, blood pressure, hydration of mucous membranes, skin turgor and perfusion, mental status, and activity Mild hypovolemia (3% to 5% volume loss) may be associated with minimal or absent clinical signs Moderate hypovolemia (6% to 9% volume loss) will have clinical signs apparent, which may include tachycardia, orthostatic blood pressure changes, dry mucous membranes, and delayed capillary refill time Several dehydration scores (Gorelick score, WHO score, and clinical dehydration score) have been proposed to aid in estimating degrees of dehydration based on clinical findings, with mixed results A systematic review of published data reported by Steiner et al revealed that the most useful individual signs for predicting 5% hypovolemia in children were delayed capillary refill time,