Exam #2 Fluids and Electrolytes Flashcards
What are some differences between adults and children?
- Their fluid requirements
- Ability to manage fluids
- the smaller and younger we are, the more water and saline is in our body.
- Longer GI tract in relation to body size.
- Immature kidneys
- Higher metabolic rate due to increased respirations and HR
Immature immune system, results in more fevers and increases metabolic rate more
TNA is one of the most routine surgeries for children
Under general anesthesia
takes about 15 - 20 min
outpatient surgery
Normal for blood tinged vomit, as long as not bright red and excessive.
have to pee and drink before you go home
Adults and Adolescents are made up of _____% normal saline.
55%
Infants are made up of ____% normal saline.
75%
Little premies in the NICU are made up of _____% normal saline.
85%
The other important thing to remember is where the water is located.
Our fluid is located in the extracellular space and our intracellular space.
Extracellular fluid is
blood within the vessels
CSF
Synovial fluid ect….
any water that is outside of the cells
It is EASY to lose
Intracellular Fluid is
water that is inside of the cell.
It is protected by the cellular membrane.
It is harder to lose and tends to stay where it is supposed to stay.
ECF electrolyte
sodium – 135 – 145 mEq/L
and chloride
ICF electrolytes
potassium and magnesium –
K+ – 3.5 – 5.0 mEq/L
Mag – 1.5 – 2.2 mEq/L
How much of an infants body weight is ECF?
ECF 40%
By the time they reach adolescent age, they will have only 20% of their body weight as extracellular.
This is why infants lose fluid volume quicker because the majority of their fluid volume is ECF.
ECF is easier lost because it is NOT protected by the cell membrane.
How much of an infants body weight is ICF?
ICF 35%
It is important to remember which electrolytes compose the water because dehydration is directly related to where our sodium and chloride is.
true
Extracellular fluid has the sodium
Most of Intracellular fluid is mainly potassium
This does not mean that it does not pass the cell membrane.
What makes kids so special?
they are composed of more water
the smaller they are, the more water they are made up of
they have different vital signs, smaller they are the faster they breathe.
babies have immature kidneys
What are the 2 ways that we lose water?
sensibile water loss
Insensible water loss
What is sensible water loss?
peeing and pooping.
Things that can be measured
What is insensible water loss?
It is what we lose through skin and respirations.
How much insensible water loss occurs through the skin?
2/3
How much insensible water loss occurs through respirations?
1/3
So for insensible water loss in a child that breathes faster than an adult…..they are going to lose more water.
also, there is more body surface area in smaller babies available compared to the amount of our weight the smaller the baby is.
This makes a huge difference in preterm babies.
They have a lot of skin compared to their core muscle and fat.
Where as if you get a big guy, they have less skin compared to their core muscle and fat.
We get more insensible water loss the smaller the baby is
true
The thing about babies and infants is they have premature kidneys.
This means that they are not as great at concentrating their urine as much as it needs to be concentrated.
They also pee more than bigger guys
Because of their fast heart rate and because they are growing so fast they have a higher metabolic rate.
This causes them to lose more water than adults.
Then we have GI tract, so in relationship to their body size, they have a longer GI tract, and it is faster.
so they tend to poop more than adults. Especially when they are infants.
The other thing to remember, especially with infants and the younger population, is that they have an immature immune system.
So they get sick more often,
they have fevers more
which increases metabolic rate and causes more fluid loss.
Things that cause water loss in an children and infants:
Could be multiple….
Higher skin surface area
More ECF
Longer GI Tract
Immature Kidneys
Immature Immune system (FEVERS)
Higher metabolic rate from increased RR and HR
So to maintain this hydration, this equality of intake and output, our body has a wonderful system that it produces.
When we get thirsty, it means that we have had a little bit of fall in our blood volume.
Which is a rise in blood osmolarity.
When there is a rise in our blood osmolarity…what happens next?
It stimulates the pituitary to produce ADH.
What does ADH do?
It makes us stop peeing and holds onto water.
If you have a rise in your blood osmolarity, and you get thirsty…
If you do not drink and become more dehydrated it will cause what?
A decrease in blood flow to the kidneys.
What happens when you have a decreased blood flow to your kidneys?
The kidneys will release renin
What is renin?
Renin is a type of hormone that produces angiotensin.
What is angiotensin?
Angiotensin is a vasoconstrictor.
Angiotensin also stimulates the release of Aldosterone.
What does aldosterone do?
Aldosterone holds onto sodium
So if you are holding onto sodium within your system, then by osmosis….you are going to pull in more water.
released from the adrenal cortex
Daily fluid calculations =
100ml
50ml
20ml
Hourly Fluid Calculations =
4ml
2ml
1ml
always check the maintenance rate so that kids don’t die.
remember that kids playing are too busy to stop and take a drink.
teach parents to make them stop and drink
So when you are talking to families about what the childs daily fluid requirements are,
we must remember that the smaller the kid, the greater amount of fluid they need.
If your patient isn’t moving, if they are just in the bed and they have IV fluids going but do not have an increased metabolic demand…..
they are fine…
That is called maintenance fluids.
If the patient has fever, vomiting, bleeding out or anything like that…..we have to give more than maintenance fluids….
when they have a fever, they have a higher metabolic rate…
so the maintenance rate has to be increased.
the rule is that for every 1 degree F the patients temperature rises….you have to add 7ml/kg/day to maintenance rate.
Fever increases insensible water loss by approximately 7ml/kg/24 hours for every 1 degree F rise in Temp above 37.2oC (99oF)
Children have a tendency to become more highly febrile than adults
What is the normal urine output for infants and toddlers?
2 - 3 ml/kg/hr