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Electrolyte Imbalances in Children
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- Describe the physiological characteristics in infants that
affect adjustments to alterations in fluid and electrolyte balance.
- Discuss factors that may result in acid-base imbalances in
- Outline a nursing plan to maintain fluid and electrolyte
balance in a child with diarrhea.
- Describe the various degrees of dehydration and how to
assess for these children.
- Differentiate between isotonic, hypotonic and hypertonic
dehydration in children.
- Discuss the therapy of oral rehydration and the nursing
You have studied adults for most of the year. When you are caring for children,
especially infants and young children, it is important to be aware that there are some
significant differences in their ability to maintain fluid and electrolyte balance.
Look at the following chart to see what those differences are and their clinical
Kidneys - Infants and young children are unable to to concentrate or
dilute urine as well as adults and also unable to conserve or excrete sodium as well.
||Infants are more likely to become
dehydrated more quickly. Given an episode of gastroenteritis, their bodies do not
conserve fluid well and the loss of intake and increased output produce exaggerated
effects. On the other hand, children who are given an overload of fluid are also
unable to compensate well and can easily get into cardiac overload.
- An infant has a greater surface area to body mass than an adult therefore insensible
loss (sweating) can be greater. Metabolism is also greater because of the larger
mass of active tissue.
||Infants with fevers will have greater fluid
loss from sweating than older children. During a fever the infant's metabolism will
also climb which will increase the fluid loss through the respiratory system. Children are
prone to illnesses that involve fluid losses and fevers.
|Metabolic Rate - Infants
generally have a high metabolic rate which makes replacement of water and electrolytes and
||Given an already high metabolism, the
addition of illness (fever, infection) casues the to produce increased wastes via
metabolism. The immature kidneys may have difficulty filtering large amounts of wastes.
|Total Body Water -
Proportionately, infants and small children have greater percentages of body water which
is replaced by fat and muscle in the older child/adult. Until about the age of 2,
one-half of the total body water (TBW) is extracellular.
||Infants and children are prone to illnesses
that increase water losses.
|Intake and Output -
Children take in and exrete a larger amount of fluid proportionately than an older child.
Because the daily exchange of ECF is high in the infant, there is little fluid
||Dehydration during vomiting or diarrhea
happens quickly because there is a smaller reserve of fluid in the infant.
Illnesses that produce fluid and electrolyte
losses in children
Diarrhea can causes dehydration, electrolyte imbalances and metabolic acidosis.
Infants and young children are more prone to the deleterious effects of diarrhea
than older chidlren. This is most likely due to their immature systems.. There
are many causes for diarrhea which inlcude bacterial, viral and parasitic pathogens.
We also know that antibiotics, ear infections, respiratory infections and urinary
tract infections are also associated with diarrhea. Remember infants are generally
at high risk for ear infections due to the shape and angles of their eustachian tube. They
are also exposed to viral and bacterial infections with siblings and at daycare.
Diarrhea also occurs in areas of inadequate sanitation, crowding, poor water sources and
areas where contaminated milk is served.
- Rotavirus - is one type of virus that causes diarrhea, especially in young children.
It is commonly characterized by explosive, green, watery, foul smelling diarrhea.
It is a common cause of diarrhea in the child care setting. Rotavirus
infection usually occurs during the winter months. Some children have no symptoms of
rotavirus infection while others may have severe vomiting, watery diarrhea and fever.
Rotavirus is highly contagious via direct contact with the virus (fecal-oral).
Often, another child or adult touches a surface that has been contaminated and then
touches his or her mouth. The daycare setting with multiple diaper changes and natural
child - child contact increases the possibility of group illness.
Vomiting is common in childhood (especially related to minor GI viral infections) and
becomes a problem when adequate intake of fluid and electrolytes does not accompany the
illness. Causes of vomiting are diagnosed by the history of the espisodes,
color/amount/character of the vomitus, and pain involved.
Assessing for Dehydration
Table 28-7 is an excellent source for learning the
signs and symptoms of dehydration in an infant or young child. Areas for you to
- Progression of symptoms from mild to moderate dehydration
- Physical assessment of each of the symptoms
Types of Dehydration and Clinical Implications
|Type of Dehydration
|Isotonic Dehydration - electrolyte and water losses
happen in equal proportions .
Most common type of dehydration
|The greatest threat to the child is hypovolemic shock
because most of the fluid loss is from the extracellular compartment. Treatment
would be IV fluids
|Hypotonic dehydration - greater electrolyte deficit than
water deficit. This can happen with diuretic therapy, renal failure, presence of
antidiurtetic hormone or excessive tube drainage, bleeding, vomiting and diarrhea.
Fluid shifts to the intracellular spaces rapidly and the body perceives itself to
be in shock much faster than with isotonic dehydration
*Giving children large amounts of electrolyte free solution (water) to replace diarrhea.
*Giving IV solutions without Na+ to the patient who is NPO
*Tap water enemas
*Children with cystic fibrosis who secrete large amount of Na+ in their sweat
|Hypertonic dehydration - greater water loss than
||*Most dangerous because shock symptoms are less apparent. Yet fluid
deficit is occuring. Seizures and neurological imbalances can occur.
*When insensible loss from the skin ans repsiratory tract is high
*Any clinical condition that depletes the body of water
Estimating Fluid Requirements
In caring for children with fluid and electrolyte imbalances, you will need to
monitor their intake and output carefully. How do you know when
"encouraging" fluids, how much is fair, good or excellent? Why are IV
rates set at 17 cc/hour or 42 cc/hr?
One such way to estimate body fluid requirements is using the following formula.
||Volume of maintenance fluid
|Child weighing 1 - 10 kg
|Child weighing 11 - 20 kg
||Needs 1,000 cc + 50cc/kg over 10 kg
|Child weighing greater than 20 kg
||Needs 1,500 cc + 20cc/kg over 20 kg
Therefore, a child weighing 5 kg. would need 100 X 5 = 500cc/24 hours
A child weighing 15 kg would need 1000 + (50cc X 5kg) = 1000 + 250 = 1250cc/24 hours
A child weighing 24 kg would need 1500 + (4kg X 20cc) = 1500 + 80 = 1580cc/24 hours
Can you figure out how much IV fluid the child would get each hour if the child were
Or how many bottles/cups of fluid the child needs that is not NPO?
Remember, children who are not experiencing illness
tend to drink enough or respond to thirst cues adequately to prevent themselves from
becoming dehydrated. Illnesses that tend to make children more prone to dehydration
fibrosis (increased respiratory effort, increased metabolism, increased mucous
controlled diabetes (polyuria).
Oral rehydration is recommended for mild to moderate
dehydration. The goal of oral rehydration is to gradually increase fluids starting
with very small amounts. This allows the child to get used to the fluids and
decreases the chance of vomiting. Withholding fluids and food for 24 hours is no
longer recommended. We now know that infants and small children dehydrate too
rapidly to encourage the withholding of fluids. But remember, replacement is with
small amounts - amounts that can get absorbed even before reaching the stomach so as not
to stimulate vomiting.
Fluids used to orally rehydrate children are electrolyte based. A few common
guidelines to follow are:
- Use of an oral rehydration solution like Pedialyte is the best
- Ongoing stool losses should be replaced 1:1 with an oral
- Children who are vomiting can be given 5-10cc every 1-5 minutes so
that fluids can be absorbed without stimulating vomiting
- NO LONGER RECOMMENDED
1. BRAT diet (banana, rice, applesauce and toast) - little nutritional value, high
carbohydrate and low in electrolytes
:2. Pop, jello, fruit juices - high carbohydrate, low nutritional value and high
3. Caffeinated drinks - have a mild diuretic affect