Fluid And Electrolytes Flashcards
Transcellular space
Fluid in specialized cavities like CSF and pericordal area
Intravascular space
Fluid in the vascular space
Interstitial fluid
Fluid surrounding the cell
Developmental differences btwn kids and adults
- inc body surface area to BMI
- higher metabolic rates
- higher body water content
- inc fluid intake and output relative to size
- larger quantities of ECF
- immature kidney rxn
3 elements of water balance
- maintenance—normal ongoing losses of fluids and electrolytes
- deficit—total amt of fluids and electrolytes lost from an illness
- on-going losses—requirement of fluids and electrolytes to replace ongoing losses (from third space loss, blood loss, diarrhea)
What should the amount of water ingested equal roughly…
The amount of urine excreted in a 24h period
Water in food and from oxidation closely approximates…
The amount lost in feces and thru evaporation
Holliday-Segar method
Body weight method to determine fluid requirements–100 mL/first 10 kg, 50 mL/second 10 kg, 20 mL/each kg after; divide by 24 to get hourly requirements
Factors inc maintenance fluid requirements
Fever-temp above 99
Tachypnea
Increased temp of the environment
Burns
Ongoing losses-diarrhea, vomiting, NG tube
output, high output kidney failure.
Diabetic ketoacidosis, diabetes insipidus
Shock
Radiant warmer, phototherapy, under lights
Postop bowel surgery
Factors dec maintenance fluid requirements
• Skin: Mist tent, incubator, swamp bed (premature infants)
• Lungs: Humidified ventilator
• Renal: Oliguria, anuria
• Misc.: Hypothyroidism
• Congestive Heart Failure
• Increased intracranial pressure
• Syndrome of inappropriate antidiuretic hormone (SIADH)
Symptoms of fluid excess
Edema, slow bounding pulse, crackles in lungs, lethargy, hepatomegaly, weight gain, seizures, coma
Causes of excretion failure
- Renal failure
- CHF
- malnutrition
Causes of excess water intake
- excessive oral intake
- hypotonic overload
- plain water enemas
NC for fluid excess
- limit intake
- diuretics
- monitor VS
- monitor neurological status
- seizure precautions
Causes of fluid depletion
- lack oral intake
- abnormal losses from diarrhea, vomit, hyperventilation, burns, hemorrhage
- these causes can dehydrate much faster in kids that adults (ECF is lost first when fluid loss occurs)
Isotonic dehydration
- Electrolyte loss=water loss
- Serum Na in normal range
- about 80% of all dehydration patients
Hypertonic dehydration
- water loss is greater than electrolyte loss
- serum Na is greater than 145 mEq/L (correct slowly)
- about 15% of all dehydration patients
- physically dry rough skin, inc muscle tone
Hypotonic dehydration
- electrolyte loss greater than water loss
- serum Na less than 135 mEq/L
- about 5% of all dehydration pts
Are labs needed for dehydration?
No, look at physical appearance
Oral rehydration therapy
- only for when child is alert, awake, not in shock
- rapid losses over 4-6h, replacement for continuing losses, providing maintenance fluid requirements
Parenteral fluid therapy
Occurs when fluids can’t be orally digested; 3 phases—
1. Initially used to increase ECF quickly
2. Replace, maintain, catch up with fluid losses
3. Introduce oral feedings and gradual correction of total body deficits
Electrolyte amounts
Na 135-150
K 3.5-5
Ca 8.5-10.5
Hyponatremia CM
- Neurogenic (Na < 125
meq/L):Behavior change,
irritability, lethargy,
headache , dizziness,
apprehension - Cardiovascular: Increased
heart rate, decreased
blood pressure, cold,
clammy skin - Muscle cramps
(especially abdomen) - Nausea
Hyponatremia etiologies
- fever
- inc water intake w/o electrolytes
- dec Na intake
- diabetic ketoacidosis
- burns and wounds
- SIADH
- malnutrition
- CF
- renal disease
- V/D/nasogastric suction
Hypernatremia CM
- Intense thirst
- Oliguria
- Agitation
- Flushed skin
- Peripheral and pulmonary
edema - Dry, sticky mucous
membranes - Nausea and vomiting
- Severe CNS symptoms (Serum
Na >150 meq/L):
disorientation, seizure,
hyperirribility when at rest
Hypernatremia etiologies
- Water loss or deprivation
- High sodium intake
- Diabetes insidipus
- Diarrhea
- Fever
- Hyperglycemia
- Renal disease
- Increased insensible loss
Hypokalemia CM
- Muscle: cramps(leg),
weakness - CVS: weak or irregular
pulse, tachycardia,
bradycardia, cardiac
arrythmias, hypotension - GI: ileus or decrease of
bowel movement - CNS symptoms:
irritability, fatigue,
paralysis, weakness
Hypokalemia etiologies
- Stress
- Starvation
- Malabsorption
- Excess loss of fluids
through vomiting,
diarrhea, sweat, n/g tube - Diuretics (furosemide,
ethacrynic acid, thiazide) - IV fluid without
potassium - Corticosteroids
- Diabetic ketoacidosis
Hyperkalemia etiologies
- Increase intake of
potassium - Decrease urine excretion
- Kidney failure
- Metabolic acidosis
- Hyperglycemia
- Potassium-sparing
diuretics - Dehydration (severe)
- Rapid IVF of potassium
- Burns
Hyperkalemia CM
- Irritability, Anxiety
- Twitching
- Hyperreflexia
- Weakness
- Flaccid paralysis
- Nausea, Diarrhea
- Bradycardia
- Cardiac arrest (K >8.5
meq/L) - Apnea, respiratory arrest
Hypocalcemia etiologies
- Inadequate calcium intake
- Vitamin D deficiency
- Renal insufficiency
- Calcium loss (infection,
burns, loop diuretics) - Alkalosis
- Hypoparathyroidism
Hypocalcemia CM
- Nervous system: numbness,
tingling of fingers, toes, nose,
ears, and circumoral area - Hyperactive reflexes, seizure
- Muscle cramps/tetany
- Laryngosplasm
- Lethargy
- Poor feeding in neonates
- Positive Trousseaus and Chvostek’s sign
- Hypotension, Cardiac arrest
Hypercalcemia etiologies
• Milk alkali syndrome (chronic
intake of calcium carbonate,
or milk)
• Excessive IV or oral calcium
administration
• Acidosis
• Prolonged immobilization
• Hypoproteinemia
• Renal disease
• Hyperparathyroidism
• Hyperthyroidism
Hypercalcemia CM
• Lethargy, weakness
• Anorexia, thirst
• Itching
• Behavior changes
• Confusion, stupor
• Nausea, vomiting, constipation
• Bradycardia, cardiac arrest
What are most pediatric maintenance solutions made of?
Dextrose and NaCl
Hypotonic solution
- fewer solutes than Intracellular fluid
- fluid shifts into cells
- for cellular hydration
- 0.45NS, 2.5D5W, .33NS
- watch for dec BP d/t dec blood volume
- not for low BP, inc ICP, stroke, neuro pt, liver, trauma, surgery, burns
Isotonic fluids
- same tonicity as ICF
- NS, LR, D5W
- no fluid shifts
- for fluid and Lyte replacement
- watch from fluid overload, edema, diluted lab values
- no volume overload pts
Hypertonic fluids
- more solutes than ICF
- D51/2, D5NS, D5LR
- fluid shifts OUT of cells
- used for hypovolemia/vascular expansion, inc urine output (postoperative), 3rd spacing, DKA
- watch for hypervolemia, inc NaCl, extravasations, cell dehydration, hyperglycemia
- NO renal or cardiac pts (d/t pulmonary edema), dehydration
Peds infusion pumps
- check rate/amt infused every hour
- never teach kids how to turn off alarms
Mild Dehydration
All looks good but 3-5% weight loss
Moderate dehydration
6-9% wt loss, irritable, alert, thirsty, cap refill slow, slightly inc pulse and RR, normal or low orthostatic hypotension, dry membranes, less than expected tears, small tenting, normal or lightly sunk fontanelle, dec urine flow
Severe dehydration
over 10% wt loss, lethargic, looks sick, delayed cap refill, very fast, thready pulse, fast and deep RR, orthostatic to shock BP, parched membrane, absent tears, sunken eyes, mottled, cool skin, sunken fontanelle, severely dec urine flow
Mild dehydration tx
oral rehydration, add fluid for each stool they have, also maintenance therapy
Moderate dehydration therapy
Same as mild but more fluids
Severe dehydration
IV fluids bolus plus maintenance, can give oral when they are alert
IV Notes
- can put it in the scalp
- can use numbing cream
- get labs when start IV if possible
- always use pump bc safer–less drip factor issues
Normal urine output in kids
1-2 mL/kg/hr
