🔑 Key Learning

  • Clinical signs include tachypnoea, tachycardia, sunken eyes, and dry mucous membranes
  • In infants: red flags include <2 wet nappies in 24 hrs or <60% usual intake
  • Management depends on severity:
    • ORS for mild/moderate dehydration
    • IV fluids for severe cases
  • Maintenance fluids calculated using Holliday-Segar formula
  • Fluid resuscitation: 0.9% sodium chloride 10 mL/kg over <10 mins and reassess

👶 History in Infants

  • Reduced oral intake (<60% of usual feeds)
  • Decreased urine output: <2 wet nappies in 24 hours, or no urine output for 12 hours

👀 Clinical Features

  • Vital signs: Tachycardia, tachypnoea (hypotension is a late sign)
  • Neurological: Lethargy, reduced responsiveness
  • GI/insensible losses: Vomiting, diarrhoea, fever
  • Examination findings:
    • Sunken fontanelle or eyes
    • Reduced skin turgor
    • Dry mucous membranes
    • Pale/mottled skin, cold peripheries (severe)
    • Prolonged capillary refill time

💊 Management Overview

  • A to E assessment
  • Capillary blood glucose
  • Choose between:
    • Oral rehydration solution (ORS) e.g. dioralyte, if tolerated
    • IV fluids if ORS not tolerated or severe dehydration

🧪 Intravenous Fluid Therapy

💧 Routine Maintenance Fluids

  • Indicated when child is NBM or vomiting
  • Fluid choice:
    • > 28 days: 0.9% sodium chloride + 5% glucose
    • <28 days: 10% dextrose +/- additives
  • Holliday-Segar Formula:
    • First 10 kg: 100 mL/kg/day
    • Next 10 kg: 50 mL/kg/day
    • Each kg >20 kg: 20 mL/kg/day
    • E.g. 22kg = 10x100 + 10x50 + 2x20 = 1540ml per 24 hours 
Weight RangeVolume per 24hr
First 10 kg100 mL/kg
Next 10 kg50 mL/kg
Each kg >20 kg20 mL/kg

     

♻️ Replacement Fluids (Dehydration)

  • Replacement corrects a fluid deficit / hypovolaemia
  • Fluid choice: 0.9% sodium chloride + 5% glucose ± K⁺
  • Deficit Calculation:
    • Fluid deficit (mL) = % dehydration × weight (kg) × 10
      • Mild: 5%
      • Moderate-severe: 10%
  • Total Fluids = Maintenance + Deficit

🚨 Resuscitation Fluids

  • For children in shock
  • Bolus: 0.9% sodium chloride 10 mL/kg IV or IO over <10 minutes
  • Reassess after each bolus (HR, CRT, BP)
  • After shock reversal, use 10% dehydration to guide 24hr fluid replacement

📝 Exam Clues & Clinchers

  • Infant with <2 wet nappies in 24 hrs + vomiting/diarrhoea → suspect dehydration
  • Sunken fontanelle, dry mouth, cool peripheries → moderate–severe dehydration
  • First-line resuscitation = 10 mL/kg 0.9% NaCl over <10 minutes