What are the treatment approaches for moderate and severe dehydration?

Treatment Approaches for Moderate and Severe Dehydration

Reduced osmolarity oral rehydration solution (ORS) is the first-line therapy for moderate dehydration, while isotonic intravenous fluids such as lactated Ringer's or normal saline should be administered immediately for severe dehydration, shock, or altered mental status. 1

Assessment of Dehydration Severity

Before initiating treatment, it's crucial to assess the degree of dehydration:

Moderate Dehydration (6%-9% fluid deficit):

• Loss of skin turgor
• Tenting of skin when pinched
• Dry mucous membranes
• Sunken eyes
• Decreased urine output

Severe Dehydration (≥10% fluid deficit):

• Severe lethargy or altered consciousness
• Prolonged skin tenting (>2 seconds)
• Cool and poorly perfused extremities
• Decreased capillary refill
• Rapid, deep breathing (sign of acidosis)
• Weak or absent pulse
• Low blood pressure

Treatment Algorithm

For Moderate Dehydration:

1. Oral Rehydration Therapy (ORT):

   • Administer reduced osmolarity ORS containing 50-90 mEq/L of sodium 1
   • Give 100 mL/kg over 2-4 hours 1
   • Initially provide small volumes and gradually increase as tolerated
   • Reassess hydration status after 2-4 hours

2. If oral intake is inadequate:

   • Consider nasogastric administration of ORS for patients who cannot tolerate oral intake or refuse to drink adequately 1

3. Replacement of ongoing losses:

   • Replace each watery stool with 10 mL/kg of ORS
   • Replace each episode of emesis with 2 mL/kg of fluid 1

For Severe Dehydration:

1. Immediate IV rehydration (medical emergency):

   • Administer boluses (20 mL/kg) of isotonic fluids (lactated Ringer's or normal saline) 1
   • Continue boluses until pulse, perfusion, and mental status normalize
   • May require two IV lines or alternate access sites in critical situations

2. Monitoring:

   • Continue IV rehydration until pulse, perfusion, and mental status normalize
   • Consider central venous pressure monitoring and urinary catheter in severe cases 1
   • Aim for urine output >0.5 mL/kg/h 1

3. Transition to oral rehydration:

   • When level of consciousness returns to normal, remaining deficit can be replaced orally 1
   • Frequently reassess hydration status to monitor adequacy of replacement therapy

Maintenance Phase

After successful rehydration:

1. Fluid maintenance:

   • Continue to replace ongoing losses with ORS until diarrhea and vomiting resolve 1
   • Administer maintenance fluids appropriate for age and weight

2. Dietary management:

   • Resume age-appropriate usual diet during or immediately after rehydration 1
   • Continue breastfeeding in infants throughout the diarrheal episode 1
   • For older children and adults, foods like starches, cereals, yogurt, fruits, and vegetables are recommended 1
   • Avoid foods high in simple sugars and fats

Adjunctive Therapies

1. Antimotility agents:

   • Should not be given to children <18 years with acute diarrhea 1
   • May be given to immunocompetent adults with acute watery diarrhea after adequate hydration 1
   • Avoid in inflammatory diarrhea or diarrhea with fever at any age

2. Antiemetics:

   • Ondansetron may be given to children >4 years and adolescents to facilitate oral rehydration when vomiting is present 1

3. Probiotics:

   • May be offered to reduce symptom severity and duration in immunocompetent patients 1

4. Zinc supplementation:

   • Beneficial in children 6 months to 5 years in areas with high prevalence of zinc deficiency 1

Common Pitfalls to Avoid

1. Delaying treatment for severe dehydration - this is a medical emergency requiring immediate IV fluids
2. Overhydration in elderly patients with heart or kidney failure - monitor closely during fluid administration 1
3. Using antimotility drugs inappropriately - avoid in children and in inflammatory diarrhea
4. Neglecting ongoing losses - continue to replace stool and vomit losses throughout treatment
5. Rapid correction of hypernatremic dehydration - aim for slow decrease in plasma sodium (<0.5 mmol/L/h) to avoid seizures 2

By following this structured approach to rehydration therapy based on the severity of dehydration, clinicians can effectively manage patients with moderate to severe dehydration while minimizing complications and improving outcomes.