Pediatric Fluids, Electrolytes, and Dehydration

What is dehydration in pediatrics?

a potentially harmful reduction in the overall fluid/water in the body which occurs when intake of fluid/electrolytes is less than loss fluid/electrolytes

What are typical causes of dehydration in pediatrics?

• fever

• gastrointestinal losses

• sweating/excessive heat/burns

• polyuria

• imbalance in regulation of sodium/water

In general which pediatric age group does dehydration occur more quickly in?

neonates and infants

What determines the severity of dehydration?

((pre-illness weight - illness weight) / pre-illness weight ) x 100%

What loss of body weight is mild dehydration in infants?

1-5%

What loss of body weight is mild dehydration in older children?

1-3%

What loss of body weight is moderate dehydration in infants?

6-9%

What loss of body weight is moderate dehydration in older children?

4-6%

What loss of body weight is severe dehydration in infants?

> 10%

What loss of body weight is severe dehydration in older children?

>6%

When should you refer a child with concenr for dehydration?

• caution with infants (3-6 months old)

• persistent vomiting

• signs/symptoms of severe hydration requiring IV fluids

• diarrhea/vomiting associated with high fever lasting for several days

• severe abdominal pain or abdominal distension

• bloody diarrhea

• underlying disease or illness that require closer observation with illness

How do you calculate fluid deficit (L)?

% dehydration x pre-illness weight / 100

What is the goal of therapy in dehydration?

restore fluid and electrolyte balance in combination with early introduction of appropriate food and oral liquid, as tolerate

How do you treat mild to moderate dehydration?

oral rehydration therapy in outpatient setting

How do you treat severe dehydration?

intavenous fluids

What is the ORT dosing for mild dehydration?

50 mL/kg over 4 hours, reassess status every 2 hours

What is the ORT dosing for moderate dehydration?

100 mL/kg over 4 hours, reassess status every hour

What is phase 1 of IV fluids for severe dehydration?

10-20 mL/kg/dose of NS or LR over 30-60 mins bolus; can repeat up to 3 times based on symtpoms

What is phase 2 of IV fluids for severe dehydration?

first 8 hours: calculate and replace fluid deficit

next 16 hours: calculate and provide maintenance rate

What are the monitoring parameters for dehydration treatment?

• normalization of blood pressure

• adequate urine output

• improvement in clinical signs and symptoms of dehydration

• normalization of serum electrolytes and other laboratory parameters

What should be in the IVF bag for severe dehydration?

sodium, dectrose, and potassium

Why should sodium be in the IVF bag?

to avoid hyponatremia, sodium shifts

What concentration of sodium should an IVF bag contain?

0.9% normal saline

What concentration of dextrose should an IVF bag contain?

D5W

What concentration of potassium should an IVF bag contain?

20 mEq

When should you use caution adding potassium into an IVF bag?

neonates, renal failure, etc.

How do you calculate maintenance IVF rate?

4-2-1 method:

4 mL/kg/hour if <10kg

40 mL/hr + 2mL/kg/hour x weight -10kg if 10-20 kg

60 mL/hr + 1mL/kg/hour x weight - 20kg if >20kg

What is the MOA of ondansetron?

selective 5-HT3 receptor antagonist, blocks serotonin at peripheral vagal nerve terminals and at central chemoreceptor trigger zone

What is the recommendation for ondansetron for gastroenteritis in pediatrics?

single dose to assist patient in tolerating ORT

What is the age range for ondansetron?

> 6 months old

What is the recommended dose for ondansetron for pediatrics?

0.15 - 0.3 mg/kg/dose

• 8-15 kg: 2 mg/dose

• 15-30 kg: 4 mg/dose

• > 30 kg: 8 mg/dose

What are the available dosage forms of ondansetron?

0.8 mg/mL oral solution; tablet and ODT: 4mg, 8mg; 4mg/2mL injectable solution

What are the ADRs of ondansetron?

risk of QTc prolongation, arrythmias

What are the counseling points for chewable tablets?

chew completely before swallowing; can drink liquids to aid in swallowing, but not required

What are the counseling points of orally disintegrating tablets?

place on top of tongue & allow to dissolve then swallow; do not use liquids to dissolve, no liquids required after; usually takes < 60 seconds

What are examples of probiotics?

lactobacillus rhamnosus GG or saccharomyces boulardii

What is the mechanism of probiotics?

assists in reestablishing normal intestinal flora, suppresses growth of pathogenic microorganisms through lactic acidic resulting in acidic environment

What is the recommendation of probiotics?

low quality of evidence

What is the role of zinc?

not routinely used in developed countries

What is the dose of zinc?

expressed in terms of elemental zinc:

< 6 months: 10 mg/day for 10-14 days

>/= 6 months and children: 20 mg daily for 10-14 days, lower doses of 5-10 mg may be associated with less diarrhea

What are the dosage forms of zinc?

dispensed as zinc sulfate: 50mg and 220mg capsules; 220 mg elemental

What are examples of ORTs?

enfalyte, pedialyte, rehydralyte, ceralyte