What is the management of dehydration?

Management of Dehydration

Dehydration management requires immediate assessment of severity followed by oral rehydration solution (ORS) as first-line therapy for mild-to-moderate cases (50-100 mL/kg over 2-4 hours), while severe dehydration demands immediate intravenous isotonic crystalloid boluses of 20 mL/kg until hemodynamic stability is achieved, with nutrition maintained throughout treatment. 1, 2, 3

Initial Assessment and Severity Classification

Determine dehydration severity through physical examination:

• Mild dehydration (3-5% fluid deficit): Increased thirst, slightly dry mucous membranes 1, 2
• Moderate dehydration (6-9% fluid deficit): Loss of skin turgor, dry mucous membranes 1, 2
• Severe dehydration (≥10% fluid deficit): Severe lethargy or altered consciousness, prolonged skin tenting, hypovolemic shock 1, 2, 3

Most reliable clinical indicators include rapid/deep breathing, prolonged skin retraction time, decreased perfusion, and capillary refill time (though fever and age affect this measurement). 1, 2 Sunken fontanelle and absence of tears are less reliable. 1

Treatment Algorithm by Severity

Mild Dehydration (3-5% Fluid Deficit)

Administer reduced osmolarity ORS (50-90 mEq/L sodium, total osmolarity <250 mmol/L) at 50 mL/kg over 2-4 hours. 1, 2 Acceptable commercial products include Pedialyte, CeraLyte, and Enfalyte/Infalyte. 1

Ongoing replacement after each stool:

• Children <2 years: 50-100 mL ORS 4, 2
• Older children: 100-200 mL ORS 4, 2
• Adults: As much as desired 4, 2

Moderate Dehydration (6-9% Fluid Deficit)

Administer ORS at 100 mL/kg over 2-4 hours using the same formulation as mild dehydration. 1, 2 If the patient cannot tolerate oral intake, use nasogastric administration at 15 mL/kg body weight/hour for infants unable to drink but not in shock. 4, 2

Severe Dehydration (≥10% Fluid Deficit)

This is a medical emergency requiring immediate action:

1. Administer IV isotonic crystalloid (lactated Ringer's or normal saline) boluses of 20 mL/kg body weight 1, 3
2. Continue boluses until pulse, perfusion, and mental status normalize 1, 3
3. Once stabilized, transition to ORS for remaining deficit replacement 1, 3

Special consideration: Malnourished infants require smaller-volume, frequent boluses of 10 mL/kg due to reduced cardiac capacity. 3

For infants in shock, use nasogastric tube only if IV equipment is unavailable. 4, 2

Reassessment and Monitoring

Reassess hydration status after 3-4 hours and adjust treatment based on current degree of dehydration. 4, 2 Monitor patient weight and clinical signs throughout therapy. 2

For patients with renal or cardiac compromise, monitor serum osmolality and perform frequent cardiac, renal, and mental status assessments to avoid iatrogenic fluid overload. 1

The induced change in serum osmolality should not exceed 3 mOsm/kg/h during fluid replacement. 1

Nutritional Management During Treatment

Do not delay feeding—"resting the bowel" through fasting is contraindicated and delays recovery. 4, 1, 2

For infants:

• Continue breastfeeding throughout the illness 1, 2, 3
• If formula-fed, dilute with equal volume clean water until diarrhea stops 4

For children >4-6 months:

• Provide freshly prepared foods (cereal-bean or cereal-meat mixes with vegetable oil) 4, 2
• Offer food every 3-4 hours (more frequently for younger children) 4, 2
• After diarrhea stops, provide one extra meal daily for a week 4, 2

Resume age-appropriate diet during or immediately after rehydration is complete. 1, 2

Ongoing Fluid Replacement

Replace ongoing losses with ORS until diarrhea and vomiting resolve: approximately 10 mL/kg for each watery stool and 2 mL/kg for each vomiting episode. 3

Encourage increased intake of locally available fluids that prevent dehydration (cereal-based gruels, soup, rice water). 4, 2

Critical Pitfalls to Avoid

Do not use soft drinks, apple juice, or Gatorade for rehydration—these have inappropriate electrolyte composition and high osmolality that may worsen dehydration. 4, 1, 2, 3

Anti-diarrheal agents are contraindicated for treatment of diarrheal disease. 4, 2 Avoid antimotility drugs (e.g., loperamide) in children <18 years. 2

Antimicrobial drugs are contraindicated for routine treatment of uncomplicated watery diarrhea unless specific indications exist (cholera, shigella dysentery, amoebic dysentery, acute giardiasis). 4

When to Switch to IV Therapy

Transition from ORS to IV rehydration if:

• Severe dehydration, shock, or altered mental status present 1
• Paralytic ileus develops 1
• Patient cannot tolerate oral/nasogastric intake 1
• ORS therapy fails after adequate trial 1

Evidence supporting ORS: A meta-analysis of 17 RCTs involving 1,811 pediatric patients demonstrated no clinically important differences between ORS and IV therapy in rehydration success, weight gain, electrolyte abnormalities, or diarrhea duration, supporting ORS as the safer first-line approach. 1

Adjunctive Therapies

Consider only after adequate hydration is achieved:

• Ondansetron may facilitate oral rehydration tolerance in children >4 years with vomiting 2
• Probiotic preparations may reduce symptom severity and duration 2
• Oral zinc supplementation for children 6 months to 5 years in areas with high zinc deficiency prevalence 2