Fluid & Electrolyte - Review

Question 1

Infant water content

Answer 1

70-80% water

Question 2

Adult water content

Answer 2

50-60% water

Question 3

Older adult water content

Answer 3

45-55%

Question 4

Body Fluid Compartments: Intracellular

Answer 4

Inside the cells
- 2/3 of fluid in your body is inside cells
- low in Na+
- high in K+

Question 5

Body Fluid Compartments: Extracellular

Answer 5

Outside of the cells
- 1/3 of fluid outside cells
- high in Na+
- low in K+
Edema: that is usually fluid that is in the interstitial space

Question 6

2 components of ECF

Answer 6

1. Plasma (intravascular) - inside the blood
2. Between cells (interstitial and lymph)

Question 7

Transcellular: can become a “third space”

Answer 7

• CSF, GI tract & pleural, synovial, & peritoneal spaces
• ver small compartment. very important. 1L
• when you have extra transcellular fluid it means it was at the expense of fluid in other areas
• ex. acites. that fluid is not available to other parts of the body. not easily transferred to other areas

Question 8

In Liters:
- plasma
- interstitial
- intracellular

Answer 8

3 L
10 L
28 L

Question 9

Hydrostatic and Oncotic Pressure

Answer 9

Arterial end of capillary: hydrostatic pressure exceeds plasma oncotic pressure so the net movement is into the interstitium. Want to send nutrition, oxygen into the tissues. Moves by the gradient
On the venous end: hydrostatic pressure is lower than plasma oncotic and so fluid moves back into the venous system
Oncotic pressure: 25mmHg intravascular, 1 mmHg intersitial. Albumin is the main protein that maintains this pressure. too large to leave capillary
cell water moves through interstitial space and into cells through osmosis

Question 10

Intracellular extracellular ration in preterm neonate

Answer 10

intracellular is quite a bit smaller than the extracellular fluid
The extracellular fluid decreases proportionately as a person gets older

Question 11

Neonates and infants:
ECF
Daily fluid requirement
Daily losses

Answer 11

proportionately higher
higher with little volume reserve -> vulnerable to dehydration
proportionately greater daily losses; more urine output, insensible losses because they breathe faster: more dependent on adequate intake

Question 12

Body surface area of infants
Resp and metabolic rates

Answer 12

larger body surface area - heat loss and water loss
higher respiratory and metabolic rates

Question 13

Kidneys of infants

Answer 13

immature kidneys - inefficicent at excreting waste products. urine is quite dilute. unable to regulate fluid balance. infants can’t concentrate or dilute urine properly. can’t manage acid-base balance with H+ ion concentrations so they are quite vulnerable.

Question 14

Isotonic Dehydration

Answer 14

Electrolyte & water deficits are in balanced proportions
Major loss is from ECT -> hypovolemic shock
Na+ is normal
Losing Na+ and water at the same proportions
Shock is the biggest threat to life

Question 15

what is the most common type of dehydration in children

Answer 15

isotonic dehydration

Question 16

Normal Na+ values

Answer 16

130-150 mEq/L

Question 17

Hypotonic Dehydration

Answer 17

Electrolyte deficit exceeds water deficit
water transfers from ECT to ICF -> shock; bran cells swell
physical signs more severe with smaller fluid losses - because the ECF is moving into the cells.
Brain cells are very vulnerable. can end up with very severe neuro signs like seizures. Losing even more fluid from ECF.
Symptoms are signs of hypovolemia

Question 18

Na + value in Hypotonic dehydration

Answer 18

< 130 mEq/L

Question 19

Hypertonic Dehydration

Answer 19

water loss is excess of electrolyte loss
Fluid shifts from ICF to ECF
Greater degree of water loss for same intensity of physical signs -> shock is less apparent
Seizures more likely
Cerebral changes - may be permanent
Symptoms are less severe for the degree of dehydration which makes it the most severe because it can be missed

Question 20

what is the most dangerous type of dehydration

Answer 20

hypertonic dehydration is most dangerous & requires more specific fluid therapy

Question 21

Na+ value in hypertonic dehydration

Answer 21

Na+ > 150 mEq/L

Question 22

Causes of Hyponatremia

Answer 22

Gain of relatively more water than Na+
Loss of relatively more Na+ than water

Question 23

Gain of relatively more water than Na+

Answer 23

Excessive IV D5W (D5W is 5% dextrose in water. Because it is such a small amount of sugar, when the dextrose gets into the body it is immediately metabolized and once it is metabolized, we are left with only water. So it is like giving free water)
Excessive tap H2O enema
Irrigation of body cavities with distilled H2O
Forced excessive intake of tap H2O

Question 24

Loss of relatively more Na+ than H2O

Answer 24

Diarrhea or vomiting with replacement by tap H2O only instead of fluid containing Na+
They should be taking in some kind of electrolyte solution (pedialyte)

Question 25

Causes of hypernatremia

Answer 25

Loss of relatively more H2O than Na+
Gain of relatively more Na+ than H2O

Question 26

Loss of relatively more H2O than Na+

Answer 26

Diarrhea and vomiting without fluid replacement. Not able to keep water down, not tolerating it.
Diabetes insipidus: pee a lot
Excessive sweating without fluid replacement
High solute intake without adequate H2O

Question 27

Gain of relatively more Na+ than H2O

Answer 27

Inability to communicate thirst
Limited or no access to water
High solute intake without adequate H2O (tube feedings)
Hypertonic saline