Fluid Replacement in Dengue

WHO Grading - Quick Reference

1. Dengue Fever (DF) - Outpatient Oral Therapy

• Oral rehydration solution (ORS), fruit juices, and electrolyte-containing fluids - preferred over plain water, as plain water does not replace electrolytes lost from fever and vomiting
• Caution: Glucose-containing fluids may exacerbate hyperglycaemia in diabetics and during physiological stress
• Paracetamol for fever; dose interval not less than 6 hours. Tepid sponging for persistent high fever
• Avoid aspirin, ibuprofen, and all NSAIDs - they aggravate gastritis, bleeding, and aspirin may precipitate Reye's syndrome
• IV fluids indicated only if persistent vomiting or refusal to feed

2. DHF Grades I & II - IV Fluid Algorithm

• Reduce IV crystalloid stepwise: 6 ml/kg/h → 3 ml/kg/h (2-4 h) → 1.5 ml/kg/h (2-4 h)
• Discontinue IV after 24-48 hours

• Increase to 10 ml/kg/h crystalloid for 2 hours, reassess

• Blood transfusion: 10 ml/kg whole blood or 5 ml/kg packed RBCs
• After improvement: step down to 10 → 6 → 3 ml/kg/h, discontinue after 24-48 h

3. DHF Grade III (Compensated Shock) - IV Fluid Algorithm

• Step down: 10 ml/kg/h → 6 ml/kg/h (2-4 h) → 1.5 ml/kg/h (2-4 h)
• Discontinue IV after 24-48 hours

• Give IV colloid OR crystalloid 10-20 ml/kg over 1 hour
• Colloids used: Dextran 40 or degraded gelatine polymer (polygeline)

• Blood transfusion: 10 ml/kg whole blood or 5 ml/kg packed RBCs
• If still refractory hypotension → check ABCS (Acidosis, Bleeding, Calcium/electrolytes, Sugar)
• If VS still not improving → IV inotropes with crystalloid maintenance by Holliday-Segar formula

4. DHF Grade IV (Profound Shock / DSS)

• Same algorithm as Grade III but shock is more profound (undetectable BP/pulse)
• Oxygen to all patients in shock - mandatory
• IV crystalloid resuscitation initiated immediately on hospitalization
• If already received ~1000 ml IV fluid and no improvement: switch to colloidal solution (Dextran 40/haemaccel) or, if Hct is declining, fresh whole blood 10-20 ml/kg/h
• For persistent shock with declining Hct despite colloid - suspect internal bleeding; give fresh whole blood 10 ml/kg/h routinely as a precaution

5. Indications for Red Cell Transfusion

1. Overt blood loss ≥10% of total blood volume - give whole blood or components
2. Refractory shock despite adequate IV fluids with declining Hct
3. Replacement volume: 10 ml/kg body weight at a time; obtain coagulogram first
4. If fluid overload is present: use packed cells instead of whole blood

6. Types of IV Fluid - What to Use

Note: In cases of acidosis, Ringer's lactate (hyperosmolar solution) should NOT be used.

7. Monitoring Parameters

• Haematocrit: Serial monitoring every hour in shock; daily from day 3 until afebrile for 1-2 days
• Platelet count: Drop in platelets + rise in Hct = early warning for DHF
• Vital signs and urine output: Every hour in DHF grades III/IV
• Improvement defined as: Hct falls, pulse rate and BP stabilise, urine output rises
• No improvement / deterioration: Hct or pulse rate rises, pulse pressure falls below 20 mmHg, urine output falls

8. Key Principles - Summary

• Fluid therapy is entirely supportive - no specific antivirals exist for dengue
• The goal is to bridge the plasma leakage phase (typically 24-48 hours during defervescence) without causing fluid overload
• Over-resuscitation is as dangerous as under-resuscitation - fluid overload causes pulmonary oedema, particularly once plasma reabsorption begins (recovery phase)
• IV fluids should be discontinued within 24-48 hours of clinical improvement
• NSAIDs and aspirin are absolutely contraindicated in all dengue grades
• DSS patients require ICU admission