Emergency Medicine/Pediatric Rehydration

Pediatric Rehydration

• Alex Flaxmanman==

Clinical Eval of Dehydration

• Mild (3–5%): HR nl or ↓, ↓ UO, thirsty, nl PE ==
• Moderate (7–10%): cool and pale, tachy, delayed cap refill, little or no UO, irritable/lethargic, sunken eyes and fontanel, ↓ tears, dry MM, mild skin tenting ==
• Severe (10–15%): cold and mottled, pulse rapid and weak, ↓ BP, no UO, very sunken eyes and fontanel, no tears, parched MM, skin tenting, very delayed capillary refill ==

Oral rehydration

• Pick a fluid (more later) ==
• Mild dehydration- 50 mL/kg within 4 hr ==
• Moderate dehydration- 100 mL/kg over 4 hr ==
• Additional fluids as per clinical condition ==
• Vomiting with the first 2 hrs of ORS → 1 teaspoon q1-2min ==

After Rehydration

• Resume breast feeding, or usual formula/milk ==
• Resume feeding, if appropriate ==

Parenteral Rehydration

• (IVF) ==

Bolus

• 20 ml/kg, over 20 min ==
• Use isotonic fluids- NS or LR ==
• Blood, 5% albumin, plasma ==

End Points

• “Adequate intravascular volume” ==
• Clinical improvement ==
  • ↓ HR ===
  • Normal BP ===
  • Improved tissue perfusion (UO) ===
  • More alert affect ===

Post-acute Treatment

• Must complete initial rehydration ==
• Calculate amount of fluids needed ==
  • Dehydration % ===
  • Maintenance ===
  • Ongoing losses (e.g. cont’d V/D) ===
• Give ½ minus any boluses in first 8 hrs ==
• Give ½ in following 16 hrs ==

Monitoring- Give enough

• Vitals ==
  • Pulse ===
  • BP ===
  • CVP- if critically ill ===
• I/O’s ==
  • Fluid balance ===
  • UO and specific gravity ===
• Physical Exam ==
  • Daily weight ===
  • Clinical signs of depletion or overload ===
• Electrolytes ==

But not too much

• Edema ==
• Pulmonary congestion ==

Calculations- Where to start

• Mild 3–5% → 5% ==
• Moderate 7–10% → 10% ==
• Severe 10–15% → 15% ==

Calculating Deficits

• Water Deficit = % dehydration × weight ==
• Sodium Deficit = Water deficit × 80 mEq/L ==
• Potassium Deficit = Water deficit × 30 mEq/L ==

Maintenance Fluids- Goals

• Prevent dehydration ==
• Prevent electrolyte disorders ==
• Prevent ketoacidosis ==
• Prevent protein degradation ==

Maintenance Fluids- Calculations

• “100/50/20” rule ==
  • 100 ml/kg for up to the 1st 10 kg of body weight* ===
  • 50 ml/kg for up to the 2nd 10 kg of body weight ===
  • 20 ml/kg for up to the 3rd 10 kg of body weight ===
• Max total fluid/day usually 2-2.5L cc ==

Maintenance- Rate

A calculator exists for this calculation.

• “4/2/1” Rule ==
  • 0–10 kg: 4 mL/kg/hr
  • 10–20 kg: 40 mL/hr + 2 mL/kg/hr × (wt-10 kg)
  • >20 kg: 60 mL/hr + 1 mL/kg/hr × (wt-20 kg)

IV Fluids

• NS ==
  • [Na] 154 mEq ===
  • [Cl] 154 mEq ===
• LR ==
  • [Na] 130 mEq ===
  • [Cl] 109 mEq ===
  • [K] 4 mEq ===
  • [Ca] 3 mEq ===
  • [Lactate] 28 mEq ===

Special Cases

• Metabolic Acidosis (RTA, renal insufficiency) ==
  • Replace some NaCl with NaHCO3 or Na-acetate ===
• If acidosis caused by lactic acidosis, be careful giving HCO3 ==
• As correct acid-base problems, watch K ==

Special Cases (cont’d)

• Fever ==
• Premature infants ==
  • Radiant warmers ===
  • Phototherapy ===

Special Cases- Lungs

• ↑ Fluids requirement ==
• Tachypnea ==
• Tracheostomy ==
• ↓ Fluids requirement ==
• Mist tent ==
• Vent ==

Special Cases (cont’d)

• NGT ==
• Surgical drains ==

Special Cases (cont’d)

• Diarrhea dehydration ==
  • Isotonic 60-70% ===
  • Hyponatremic 10-15% ===
  • Hypernatremic 10-20% ===

IVF for Ongoing Losses

• D5 1/4 NS + 15 mEq/L bicarbonate + 25 mEq/L KCl ==
• Replace stool mL/mL every 1–6 hr ==

Summary

• Restore intravascular volume ==
  • NS 20 mL/kg over 20 min (repeat until intravascular volume restored) ===
• Calculate water deficit ==
• Calculate 24-hr water needs ==
• Calculate deficit sodium and potassium ==
• Calculate 24-hr electrolyte needs (Na, K) ==
• Select fluid (based on total water and electrolyte needs). ==
• Give ½ calculated fluid minus boluses during first 8 hrs ==
• Give ½ calculate fluid over the next 16 hrs ==
• Replace ongoing losses as they occur ==