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Treatment of hypovolemia (dehydration) in children in resource-abundant settings

Treatment of hypovolemia (dehydration) in children in resource-abundant settings
Literature review current through: Jan 2024.
This topic last updated: Jun 05, 2023.

INTRODUCTION — Fluid therapy maintains the normal volume and composition of body fluids and, if needed, corrects any existing abnormalities. In children, the most common abnormality requiring fluid therapy is hypovolemia or dehydration, often related to vomiting and diarrhea from gastroenteritis. Clinically, it is useful to divide fluid therapy into repletion therapy and maintenance therapy.

Repletion therapy replaces any current existing water and electrolyte deficits, replaces any ongoing abnormal losses, and returns the patient to a normal volume and electrolyte status.

Maintenance therapy replaces the expected ongoing losses of water and electrolytes from normal physiologic processes and maintains normal volume and electrolyte status (calculator 1 and calculator 2). (See "Maintenance intravenous fluid therapy in children".)

Volume depletion reduces the effective arterial blood volume (also called effective circulating volume [ECV]), which refers to that part of the arterial volume that perfuses the tissues. If severe hypovolemia is not corrected in a timely fashion, ischemic end-organ damage may occur and, with profound or persistent hypovolemia, shock and death may ensue.

The treatment of hypovolemia in children will be reviewed here. Related content can be found in the following topic reviews:

(See "Clinical assessment of hypovolemia (dehydration) in children".)

(See "Hypovolemic shock in children in resource-abundant settings: Initial evaluation and management".)

(See "Management of complicated severe acute malnutrition in children in resource-limited settings", section on 'Dehydration'.)

GENERAL PRINCIPLES — Repletion therapy in hypovolemic children is based on two steps:

The first step involves emergent correction of severe or marked moderate hypovolemia, ensuring a return of adequate intravascular volume and avoiding tissue damage. This is primarily provided with intravenous (IV) fluids in developed countries, although successful emergent oral rehydration therapy (ORT) has also been documented. (See 'Emergency fluid repletion phase' below.)

The second step finishes repletion of fluids and electrolyte losses in children initially treated with emergent IV fluid therapy, and is the only fluid therapy required in patients with mild to mildly moderate hypovolemia. The second step can be completed either intravenously or by ORT. (See 'Secondary fluid repletion phase' below.)

When repleting a hypovolemic child, several questions must be answered:

Does the child require emergency therapy?

By what route (oral or IV) should the fluid be delivered?

What kind of fluid should be given?

What fluid volume should be given initially and then in follow-up?

How quickly should the fluid in each step be given?

Once the child has been repleted, ongoing maintenance fluid is needed to replace ongoing losses of water and electrolytes, which is discussed separately. (See "Maintenance intravenous fluid therapy in children".)

EMERGENCY FLUID REPLETION PHASE — Rapid volume repletion is required in children with severe hypovolemia. Clinical assessment of hypovolemia is based upon physical signs that reflect the status of the effective arterial blood volume and include pulse, blood pressure, and skin turgor (table 1). If known, changes in weight and urine output from baseline values are also helpful in assessing the degree of volume depletion. (See "Clinical assessment of hypovolemia (dehydration) in children", section on 'Estimating degree of hypovolemia'.)

Degree of hypovolemia — Although the degree of hypovolemia is a continuum, hypovolemia is divided into clinical categories primarily for management decisions. (See "Clinical assessment of hypovolemia (dehydration) in children", section on 'Estimating degree of hypovolemia'.)

Severe hypovolemia — Severe hypovolemia (defined as volume depletion ≥10 percent) presents with decreased peripheral perfusion with a capillary refill of greater than three seconds, cool and mottled extremities, lethargy, and, in its worst manifestation, with hypotension or even frank shock (table 1). (See "Clinical assessment of hypovolemia (dehydration) in children".)

With severe hypovolemia with actual or evolving circulatory compromise, emergent intravenous (IV) fluid therapy should begin with rapid infusion of 20 mL/kg of isotonic saline. The child should be reassessed during and after the saline bolus, and similar isotonic fluid infusions should be repeated as needed until adequate perfusion is restored [1]. If IV access is not readily obtainable, intraosseous rehydration is an effective alternative [2]. (See "Intraosseous infusion".)

A more detailed discussion of the treatment of hypovolemic shock can be found elsewhere. (See "Hypovolemic shock in children in resource-abundant settings: Initial evaluation and management".)

Moderate hypovolemia — In patients with more moderate forms of hypovolemia, it remains uncertain whether IV rehydration should be given, and if so, how rapidly. For children with marked moderate hypovolemia (eg, estimated volume depletion >7 percent), especially if they have been unable to take oral fluids, emergent fluid administration may be appropriate. In most cases, a bolus of 10 mL/kg is given over 30 to 60 minutes with reassessment to decide on administration of a repeat IV bolus versus transition to oral therapy. In some cases of moderate hypovolemia, initial oral rehydration therapy may be sufficient to correct moderate dehydration, and no emergent repletion therapy is necessary. (See 'Oral rehydration therapy' below.)

In a Canadian trial of 226 children with hypovolemia due to gastroenteritis, there was no difference in the status of hydration two hours after initial IV fluid intervention between patients who were rapidly rehydrated (60 mL/kg) versus those who were treated with the standard 20 mL/kg over one hour [3]. Both groups received 0.9 percent saline. However, a major limitation of this study was the inconsistent and imprecise assessment of hydration [4]. As a result, patients with mild hypovolemia who may not even require IV rehydration may have been included, which may have led to a biased outcome.

Type of fluid — Isotonic crystalloid is recommended for emergent volume resuscitation in pediatric patients [1]. Isotonic saline (0.9 percent saline solution or normal saline) is the isotonic solution of choice to restore the circulatory volume. Rapid administration of hypotonic or hypertonic crystalloid solutions for emergent volume expansion can result in serious complications, including dysnatremias, cerebral edema, and, in children with marked hyponatremia, cerebral demyelination [5,6]. (See 'Therapy according to serum sodium' below.)

The use of hypotonic or hypertonic crystalloid solutions for the purpose of emergent volume resuscitation is never recommended in pediatric patients.

Dextrose is generally not added to normal saline solution. In a clinical trial of 188 children (age range six months to six years), the administration of 5 percent dextrose added to normal saline solution did not lower the rate of hospitalization compared with the standard use of normal saline solution without dextrose [7]. Children who received the dextrose-containing solution had a greater reduction in serum ketone levels, though these levels were still markedly abnormal and there was no difference between the two groups in degree of metabolic acidosis. Until further studies show that the addition of dextrose provides a significant clinical benefit without adverse effect, normal saline without dextrose is the recommended solution for emergent volume resuscitation.

Although balanced isotonic solutions (ie, lactated Ringer's) have been proposed as alternatives for initial treatment of hypovolemia in children, data to support their use are lacking. Most of the studies examining this question were done in intensive care or operating room settings, which limits their generalizability to initial rehydration for the typical child [8]. Further studies are needed to see if there are clinically meaningful differences in outcomes between balanced isotonic solutions and isotonic crystalloid [9].

Crystalloid versus colloid — Although isotonic saline-based crystalloid solutions and colloid-containing solutions have been used historically to replace extracellular fluid deficits, isotonic crystalloid solution (ie, isotonic saline) is preferred. Some clinicians have advocated the administration of a colloid-containing solution (such as 5 percent albumin or hydroxyethyl starch [hetastarch]) because of two theoretical advantages over crystalloid repletion [10]:

Plasma volume expansion is achieved more rapidly because more of the colloid solution remains in the vascular space, as opposed to saline, two-thirds of which equilibrates into the interstitium.

Risk of pulmonary edema is decreased because diminished intravascular oncotic pressure from dilutional hypoalbuminemia will not occur.

However, numerous controlled trials and systematic meta-analyses have failed to demonstrate either of these theoretical benefits in adults. Although no such data are available in children other than high-risk neonates, the same principles probably apply throughout childhood [11-13]. As a result, an isotonic saline solution is the treatment of choice in treating extracellular fluid losses in all age groups. Possible mechanisms for lack of benefit are discussed elsewhere. (See "Treatment of severe hypovolemia or hypovolemic shock in adults", section on 'Normal saline (crystalloid)'.)

In children with decreased effective arterial blood volume related to low intravascular oncotic pressure, as in nephrotic syndrome or severe sepsis, it may be useful to use colloid-containing solution (such as albumin) to restore perfusion. In these specific settings, salt-poor albumin is administered at a dose between 0.5 and 1 g/kg, and is discussed separately. (See "Symptomatic management of nephrotic syndrome in children", section on 'Patients with edema and intravascular hypovolemia' and "Evaluation and management of edema in children", section on 'Intravenous albumin infusion'.)

SECONDARY FLUID REPLETION PHASE — After severe volume depletion has been corrected with intravenous (IV) fluid, fluid repletion can continue with either continued IV fluid or oral rehydration therapy (ORT).

Oral rehydration therapy — Oral rehydration therapy (ORT) is the preferred treatment for children with mild to moderate hypovolemia or as the 2nd phase of repletion therapy in children with severe hypovolemia after effective arterial blood volume has been restored by the administration of emergent fluid therapy [14]. In a meta-analysis that compared ORT with traditional IV rehydration, the overall failure rate with ORT (defined as the need to revert to IV therapy) was only 3.6 percent, without an increased incidence of iatrogenic hyponatremia or hypernatremia [15].

ORT involves the administration of frequent small amounts of fluid by spoon or syringe. Advantages of ORT include lower cost, elimination of the need for IV line placement, and involvement of the parents/caregivers in a rehydration process they can continue at home and utilize in future illnesses. A full discussion on oral rehydration therapy is found elsewhere in the program. (See "Oral rehydration therapy".)

Intravenous rehydration therapy — Indications for continued IV therapy include:

Inability of the child to take ORT (eg, alteration in mental status, ileus, or anatomic anomaly)

Inability of the caretaker to provide ORT

Failure of ORT to provide adequate rehydration (eg, persistent vomiting)

Severe electrolyte problems in clinical setting where ORT cannot be closely monitored or electrolytes frequently assessed

The type of IV repletion fluid that is given in this second step of fluid therapy varies with the serum sodium concentration. During the second fluid phase, in addition to completing repletion, fluid and electrolytes to replace any abnormal ongoing losses as well as maintenance fluids and electrolytes must be given (table 2) (calculator 1 and calculator 2). (See "Maintenance intravenous fluid therapy in children".)

Therapy according to serum sodium — The sodium content of fluid and the rate of correction are dependent upon the serum sodium concentration defined as:

Hyponatremia − serum sodium less than 130 mEq/L

Isonatremia − serum sodium between 130 and 150 mEq/L

Hypernatremia − serum sodium greater than 150 mEq/L

The factors that contribute to the final serum sodium at presentation (the composition of the fluid that was lost, the type of fluid intake, and the ability to excrete water during the illness) are discussed separately. (See "Clinical assessment of hypovolemia (dehydration) in children", section on 'Serum sodium'.)

The majority of cases of hypovolemia caused by gastroenteritis are isonatremic, and fluid repletion can be performed in a few hours in the pediatrician's office or emergency department [16-18]. However, when hypovolemia is associated with significant hyponatremia or hypernatremia, or when hypovolemia and associated alterations in serum sodium have evolved slowly, attention also must be paid to the rate of correction of the serum sodium concentration to avoid excessive shifts of water out of (hyponatremia) or into (hypernatremia) the brain that can lead to serious neurologic complications [19]. (See "Manifestations of hyponatremia and hypernatremia in adults".)

Volume repletion is based upon calculation and replacement of water and sodium losses. The water deficit is best estimated from the fall in body weight from baseline, which is usually not exactly known. The sodium deficit is equal to the deficit per liter in serum sodium (SNa) multiplied by the volume of distribution of the osmotic effect of sodium, which is the total body water (TBW):

Na deficit = [TBW(n) x 140 mEq/L] - [TBW(c) x SNa]

where TBW(n) is the normal TBW and TBW(c) is the estimated current TBW.

The TBW in most children is approximately 60 percent of body weight. However, the proportion of body weight is higher in smaller children and infants, especially low birth weight premature infants whose TBW is approximately 80 percent of the total mass (figure 1). The TBW(c) would be the difference between TBW(n) and the fluid loss. (See "General principles of disorders of water balance (hyponatremia and hypernatremia) and sodium balance (hypovolemia and edema)", section on 'Total body water' and "Clinical assessment of hypovolemia (dehydration) in children".)

So, for a 10 kg child with a 10 percent hypovolemic loss, the following calculations can be made:

TBW(n): 0.6 x body weight = 6 L

Total fluid deficit: 10 percent of 6 L = 0.6 L

TBW(c): TBW(n) - fluid loss = 6-0.6 L = 5.4 L

Isonatremia — In patients with isonatremic hypovolemia, the above calculation can be simplified because the serum sodium concentration is close to 140 mEq/L for both the normal and current states. In addition, the difference between the two TBW states is the fluid deficit.

Na deficit = [TBW(n) - TBW(c)] x 140 mEq/L

IV therapy would consist of replacement of the fluid deficit with isotonic saline. The serum sodium concentration should not change substantially with repletion therapy, as sodium and water are given in proportion.

Hyponatremia — Hyponatremia in hypovolemic children is usually caused by the intake of hypotonic solutions. Some or most of the free water in these solutions cannot be excreted because hypovolemia also enhances the secretion of antidiuretic hormone (ADH), thereby increasing renal water reabsorption. In addition, ADH secretion due to other nonosmotic stimuli including pain, nausea and vomiting, stress, and hypoglycemia can be seen in children with hyponatremia and gastroenteritis [20]. (See "Hyponatremia in children: Etiology and clinical manifestations".)

Most hypovolemic children have mild to moderate hyponatremia (defined as serum sodium >125 mEq/L and asymptomatic) and can be treated with isotonic saline alone, similar to therapy for isonatremia (see "Hyponatremia in children: Evaluation and management", section on 'Treatment'). Isotonic saline will correct the volume depletion and raise the serum sodium at the same time. The increase in serum sodium will occur in two stages:

The serum sodium will rise because the sodium concentration in the infused isotonic saline (154 mEq/L) is higher than that in the extracellular fluid.

This will be followed by a further increase in serum sodium, as volume repletion will remove the hypovolemic stimulus to the secretion of ADH, thereby allowing urinary excretion of the excess water.

Another factor that can promote correction of the hyponatremia is the administration of potassium to a patient who is also hypokalemic. Potassium is the major intracellular solute and is as osmotically active as sodium. Thus, in a hypovolemic patient who also is hypokalemic, the addition of 40 mEq of potassium into each liter of isotonic saline allows for intracellular potassium repletion and movement of intracellular sodium to the extracellular fluid. The resulting increased intracellular osmolality due to potassium repletion also leads to water movement into the cells. Potassium can be added with the establishment of good urinary flow, adequate renal function, and ability to closely monitor serum potassium concentration. (See "Overview of the treatment of hyponatremia in adults".)

Symptomatic hyponatremia — Symptomatic hyponatremia is one of the rare clinical settings in children in which hypertonic (3 percent) saline is used (sodium concentration of 513 mEq/L compared with 154 mEq/L in 0.9 percent or isotonic saline). In the child with seizures or altered mental status, correction of hyponatremia should not be delayed. In these patients, 3 to 5 mL/kg of 3 percent saline is the suggested initial therapy. (See "Hyponatremia in children: Evaluation and management", section on 'Acute symptomatic hyponatremia' and "Hyponatremia in children: Evaluation and management", section on 'Chronic hyponatremia with severe symptoms'.)

After the initial hypertonic saline infusion, plasma sodium should be measured and, if seizures are ongoing, the infusion should be repeated. Once the acute CNS symptoms have abated, the ongoing sodium correction should be tailored so that the total daily correction including the hypertonic saline bolus is less than 12 mEq/L [21].

The primary problem with symptomatic hyponatremia is evolving cerebral edema, and the risk of morbidity from delayed therapy is greater than the risk of complication from too rapid correction and osmotic demyelination. As a result, aggressive initial correction is indicated for the first three to four hours (or until the symptoms resolve) at a rate not to exceed a rise in serum sodium of 2 mEq/L per hour [22-24]. Often, an initial goal is to raise the serum sodium by 5 mEq/L over the first several hours.

After the resolution of symptoms, fluid management is determined by calculating the deficits of sodium and water as noted above.

Hypernatremia — Hypernatremia in hypovolemic patients results from the loss of free water due to increased insensible losses because of fever or sweating, urinary concentrating defects, as in diabetes insipidus, or relatively dilute diarrheal fluid (sodium plus potassium concentration less than that in the plasma), as occurs in most cases of gastroenteritis. These deficits must be accompanied by inadequate fluid intake that would otherwise prevent a free water deficit. (See "Clinical assessment of hypovolemia (dehydration) in children", section on 'Serum sodium' and "Hypernatremia in children", section on 'Etiology'.)

Children with a serum sodium concentration above 155 mEq/L who are corrected too rapidly are at greatest risk of neurologic sequelae, particularly seizures [25,26]. This adverse response to therapy primarily occurs when the hypernatremia is corrected too rapidly at a rate exceeding 0.7 mEq/L per hour [26]. In comparison, no neurologic sequelae appear to occur if the plasma sodium concentration is lowered at a rate of ≤0.5 mEq/L per hour [27]. (See "Hypernatremia in children", section on 'Treatment'.)

Thus, the goals of therapy in children with hypovolemia and serum sodium above 155 mEq/L are correction of the volume deficit and gradual correction of the hypernatremia at a rate of less than 12 mEq/L per day (less than 0.5 mEq/L per hour). The overall fluid deficit in hypernatremic hypovolemia is a combination of the free water deficit that raised the serum sodium and an isotonic fluid deficit from the abnormal volume losses (which may be large in children with gastroenteritis and minimal in children with diabetes insipidus who have mainly free water loss).

Estimation of the free water deficit (essentially the amount of free water that would have to be lost to produce the observed elevation in serum sodium) is based upon the serum sodium and the estimated current TBW (see "Treatment of hypernatremia in adults" and "Treatment of hypernatremia in adults", section on 'Derivation of the water deficit formula'):

Free water deficit = Current TBW [(SNa/140) - 1]

Suppose, for example, a 10 kg child (TBW 0.6 times body weight) has a 1 L fluid loss and a serum sodium concentration of 156 mEq/L. The following calculations can be made:

Total fluid deficit = 10 percent of 10 kg = 1000 mL

Free water deficit = 6 L [(156/140 mEq/L) - 1] = 686 mL

Isotonic loss = Total fluid deficit - water deficit = 314 mL

During the emergent fluid phase, the patient received a 20 mL/kg bolus of normal saline (200 mL), replacing all but 114 mL of the isotonic fluid loss. (See 'Emergency fluid repletion phase' above.)

Subsequent therapy to replace water loss would include the water deficit (686 mL), the remainder of the isotonic fluid loss (114 mL), plus ongoing excess fluid losses (eg, diarrhea, vomiting, or urinary losses in diabetes insipidus) and the patient's maintenance fluid requirements. (See "Maintenance intravenous fluid therapy in children".)

The water deficit is replaced over more than 36 hours so that the serum sodium would be lowered at a rate below 0.5 mEq/L per hour. The serum sodium concentration must be monitored to ensure that the actual decrease is consistent with the therapeutic plan. (See "Hypernatremia in children", section on 'Treatment'.)

Therapy based on isotonic saline infusion — If the hypovolemic child requires hospitalization and IV therapy, an alternative method to fluid therapy recommends the use of isotonic saline for repletion of fluid losses at an initial dose of 20 to 40 mL/kg over two to four hours [28]. Maintenance fluid rates, again using isotonic saline, would be initiated when the patient became euvolemic.

This approach was suggested to prevent hospital-acquired hyponatremia associated with the administration of IV hypotonic fluids in the setting of significant ADH release [29,30]. Such hyponatremia occurs when hypotonic fluid is administered in the presence of ADH, which is released in response to nonosmotic stimuli such as significant hypovolemia, pain, or anxiety [20]. In this clinical setting, the use of isotonic saline would prevent the development of hyponatremia. Administration of isotonic saline also simplifies the treatment regimen by eliminating the need to calculate sodium and water losses. (See "Causes of hypotonic hyponatremia in adults".)

In one study of children admitted with hypovolemia caused by gastroenteritis, patients were assigned randomly to receive either hypotonic or isotonic IV fluid [31]. The administration of hypotonic solution (0.45 percent saline) did not alter the mean sodium level of children who were hyponatremic (from 132 to 133 mEq/L), but decreased the mean sodium level of children who were initially normonatremic (from 137 to 135 mEq/L). The use of isotonic solution increased mean serum sodium levels of initial hyponatremic patients (from 132 to 134 mEq/L), but there was no change in mean sodium levels in the initial normonatremic patients (from 137 to 138 mEq/L). The degree of hypovolemia was not assessed at the time of admission nor was a standardized infusion protocol used, making it difficult to draw firm conclusions about the full ramifications of this study. Moreover, the clinical significance of these small changes in sodium in normonatremic children is unclear.

Nonetheless, the use of isotonic saline infusions as the basis for fluid therapy has been recommended as a safe and effective option for hospitalized children with hypovolemia from gastroenteritis. Such an approach should not be used to formulate therapy in children with hypernatremia who need free water replacement or in those with other significant electrolyte abnormalities [32].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Fluid and electrolyte disorders in children".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

Basics topics (see "Patient education: Dehydration in children (The Basics)" and "Patient education: Rotavirus infection (The Basics)")

Beyond the Basics topics (see "Patient education: Acute diarrhea in children (Beyond the Basics)" and "Patient education: Nausea and vomiting in infants and children (Beyond the Basics)")

SUMMARY AND RECOMMENDATIONS

Goals of fluid therapy – Fluid therapy maintains the normal volume and composition of body fluids and, if needed, corrects any existing abnormalities. (See 'Introduction' above and 'General principles' above.)

Emergency repletion – The first step in treatment of hypovolemia is to correct severe volume depletion with intravenously administered isotonic fluids based on the child’s degree of hypovolemia. Clinical assessment of hypovolemia is based on physical signs that reflect the status of the effective arterial blood volume and include pulse, blood pressure, and skin turgor (table 1). (See 'Emergency fluid repletion phase' above and "Clinical assessment of hypovolemia (dehydration) in children".)

Severe hypovolemia – For children with severe hypovolemia (defined as volume depletion ≥10 percent), intravenous (IV) fluid therapy should begin with rapid infusion of 20 mL/kg of isotonic saline. The bolus may be repeated based on continued assessment of the child.

Moderate hypovolemia – For children with marked moderate hypovolemia (eg, estimated volume depletion >7 percent), especially if they have been unable to take oral fluids, emergent fluid administration may be appropriate. In most cases, a bolus of 10 mL/kg of isotonic saline is given over 30 to 60 minutes, with reassessment to decide on administration of a repeat IV bolus versus transition to oral therapy.

Continued repletion – The second step is to finish repletion of fluids and electrolytes and to begin replacement of ongoing losses, either with oral rehydration therapy or IV fluids (table 2) (calculator 1 and calculator 2).

Oral rehydration therapy – Oral rehydration therapy (ORT) is the preferred treatment for children with mild to moderate hypovolemia or as the 2nd phase of repletion therapy. ORT involves the administration of frequent small amounts of fluid by spoon or syringe. (See 'Oral rehydration therapy' above.)

Intravenous rehydration therapy based on serum sodium – For children who are unable to take or tolerate ORT, whose caregivers are unable to provide ORT, or who have severe electrolyte abnormalities requiring frequent assessment, we use IV rehydration. The sodium content of fluid and the rate of correction are dependent upon the serum sodium concentration, defined as:

-Hyponatremia − serum sodium <130 mEq/L. (See 'Hyponatremia' above.)

-Isonatremia − serum sodium 130 to 150 mEq/L. (See 'Isonatremia' above.)

-Hypernatremia − serum sodium >150 mEq/L. (See 'Hypernatremia' above.)

Volume repletion is based upon calculation and replacement of water and sodium losses. The water deficit is best estimated from the fall in body weight from baseline, which is usually not exactly known. The sodium deficit is equal to the deficit per liter in serum sodium (SNa) multiplied by the volume of distribution of the osmotic effect of sodium, which is the total body water (TBW) (see 'Therapy according to serum sodium' above):

-Na deficit = [TBW(n) x 140 mEq/L] - [TBW(c) x SNa]

where TBW(n) is the normal TBW and TBW(c) is the estimated current TBW.

The TBW in most children is approximately 60 percent of body weight. However, the proportion of body weight is higher in smaller children and infants, especially low birth weight premature infants whose TBW is approximately 80 percent of the total mass (figure 1). The TBW(c) is the difference between TBW(n) and the fluid loss.

Intravenous rehydration therapy with isotonic fluids – Alternatively, isotonic fluids can be used in most otherwise healthy children for repletion of fluid losses at an initial dose of 20 to 40 mL/kg over two to four hours. Maintenance fluid with isotonic saline is initiated when the patient became euvolemic. (See 'Therapy based on isotonic saline infusion' above.)

ACKNOWLEDGMENT — The UpToDate editorial staff acknowledges Erin E Endom, MD, who contributed to an earlier version of this topic review.

  1. Management of shock. In: Pediatric Advanced Life Support Provider Manual, Chameides L, Samson RA, Schexnayder SM, Hazinski MF (Eds), American Heart Association, Subcommittee on Pediatric Resuscitation, Dallas 2011. p.85.
  2. Rouhani S, Meloney L, Ahn R, et al. Alternative rehydration methods: a systematic review and lessons for resource-limited care. Pediatrics 2011; 127:e748.
  3. Freedman SB, Parkin PC, Willan AR, Schuh S. Rapid versus standard intravenous rehydration in paediatric gastroenteritis: pragmatic blinded randomised clinical trial. BMJ 2011; 343:d6976.
  4. Nager AL. Intravenous rehydration in paediatric gastroenteritis. BMJ 2011; 343:d7083.
  5. Jackson J, Bolte RG. Risks of intravenous administration of hypotonic fluids for pediatric patients in ED and prehospital settings: let's remove the handle from the pump. Am J Emerg Med 2000; 18:269.
  6. Ayus JC, Arieff AI. Hyponatremia and myelinolysis. Ann Intern Med 1997; 127:163.
  7. Levy JA, Bachur RG, Monuteaux MC, Waltzman M. Intravenous dextrose for children with gastroenteritis and dehydration: a double-blind randomized controlled trial. Ann Emerg Med 2013; 61:281.
  8. Lehr AR, Rached-d'Astous S, Barrowman N, et al. Balanced Versus Unbalanced Fluid in Critically Ill Children: Systematic Review and Meta-Analysis. Pediatr Crit Care Med 2022; 23:181.
  9. Florez ID, Sierra J, Pérez-Gaxiola G. Balanced crystalloid solutions versus 0.9% saline for treating acute diarrhoea and severe dehydration in children. Cochrane Database Syst Rev 2023; 5:CD013640.
  10. Rackow EC, Falk JL, Fein IA, et al. Fluid resuscitation in circulatory shock: a comparison of the cardiorespiratory effects of albumin, hetastarch, and saline solutions in patients with hypovolemic and septic shock. Crit Care Med 1983; 11:839.
  11. Wilkes MM, Navickis RJ. Patient survival after human albumin administration. A meta-analysis of randomized, controlled trials. Ann Intern Med 2001; 135:149.
  12. Finfer S, Bellomo R, Boyce N, et al. A comparison of albumin and saline for fluid resuscitation in the intensive care unit. N Engl J Med 2004; 350:2247.
  13. Perel P, Roberts I. Colloids versus crystalloids for fluid resuscitation in critically ill patients. Cochrane Database Syst Rev 2011; :CD000567.
  14. Practice parameter: the management of acute gastroenteritis in young children. American Academy of Pediatrics, Provisional Committee on Quality Improvement, Subcommittee on Acute Gastroenteritis. Pediatrics 1996; 97:424.
  15. Gavin N, Merrick N, Davidson B. Efficacy of glucose-based oral rehydration therapy. Pediatrics 1996; 98:45.
  16. Moineau G, Newman J. Rapid intravenous rehydration in the pediatric emergency department. Pediatr Emerg Care 1990; 6:186.
  17. Rahman O, Bennish ML, Alam AN, Salam MA. Rapid intravenous rehydration by means of a single polyelectrolyte solution with or without dextrose. J Pediatr 1988; 113:654.
  18. Reid SR, Bonadio WA. Outpatient rapid intravenous rehydration to correct dehydration and resolve vomiting in children with acute gastroenteritis. Ann Emerg Med 1996; 28:318.
  19. Strange K. Regulation of solute and water balance and cell volume in the central nervous system. J Am Soc Nephrol 1992; 3:12.
  20. Neville KA, Verge CF, O'Meara MW, Walker JL. High antidiuretic hormone levels and hyponatremia in children with gastroenteritis. Pediatrics 2005; 116:1401.
  21. Sterns RH, Cappuccio JD, Silver SM, Cohen EP. Neurologic sequelae after treatment of severe hyponatremia: a multicenter perspective. J Am Soc Nephrol 1994; 4:1522.
  22. Berl T. Treating hyponatremia: damned if we do and damned if we don't. Kidney Int 1990; 37:1006.
  23. Karp BI, Laureno R. Pontine and extrapontine myelinolysis: a neurologic disorder following rapid correction of hyponatremia. Medicine (Baltimore) 1993; 72:359.
  24. Sterns RH. Severe symptomatic hyponatremia: treatment and outcome. A study of 64 cases. Ann Intern Med 1987; 107:656.
  25. Finberg L. Hypernatremic (hypertonic) dehydration in infants. N Engl J Med 1973; 289:196.
  26. Kahn A, Brachet E, Blum D. Controlled fall in natremia and risk of seizures in hypertonic dehydration. Intensive Care Med 1979; 5:27.
  27. Blum D, Brasseur D, Kahn A, Brachet E. Safe oral rehydration of hypertonic dehydration. J Pediatr Gastroenterol Nutr 1986; 5:232.
  28. Holliday MA, Friedman AL, Segar WE, et al. Acute hospital-induced hyponatremia in children: a physiologic approach. J Pediatr 2004; 145:584.
  29. Hoorn EJ, Geary D, Robb M, et al. Acute hyponatremia related to intravenous fluid administration in hospitalized children: an observational study. Pediatrics 2004; 113:1279.
  30. Moritz ML, Ayus JC. Prevention of hospital-acquired hyponatremia: a case for using isotonic saline. Pediatrics 2003; 111:227.
  31. Neville KA, Verge CF, Rosenberg AR, et al. Isotonic is better than hypotonic saline for intravenous rehydration of children with gastroenteritis: a prospective randomised study. Arch Dis Child 2006; 91:226.
  32. Schwartz R. Comments from another student of Gamble and Darrow on fluids. Pediatrics 1996; 98:314.
Topic 6103 Version 36.0

References

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