Fluids and electrolytes Flashcards
Sources of fluid loss
- Insensible losses
- Urinary
- Fecal
Insensible losses in kids: %
2/3 through skin (kids skin is a higher % than of their body mass
1/3 through respiratory tract (kids have an increased RR)
Why are kids more susceptible to rapid fluid depletion before age 2? What kind of fluid are kids more likely to lose?
Children maintain a larger amount of ECF until about 2 years
Kids are more likely to lose ECF
Why do infants and children less than 2 lose a greater proportion of fluid each day? (4)
- Greater amount of BSA causes increase in insensible losses
- Increased metabolic rate: More fluid needed for metabolism
- Greater amount of metabolic wastes excreted by kidney
- Glomeruli tubules and nephrons of kidney are immature and unable to conserve H20
% H20:
- Infants
- Adults
75% in infants
55-65% in adults
Solutes in ECF (4)
Sodium
Bicarbonate
Cloride
Calcium
Solutes in ICF (4)
Potassium
Magnesium
Calcium
Phosphorus
How do you calculate the daily requirements for a kid?
Weight in kg:
- 100 mL/kg for first 10kg
- 50 mL/kg for second 20 kg
- 20 mL/kg for remainder of weight in kg
(To obtain rate per hour, divide total amount by 24 hours)
Urine output:
- Infants and toddlers
- Preschool / young school age
- Older school age / ados:
- Infants and toddlers
>2-3 mL/kg/hr - Preschool / young school age
>1-2 mL/kg/hr - Older school age / ados:
0. 5-1.0 mL/kg/hr
Serum sodium:
- Hypotonic Dehydration
- Isotonic Dehydration
- Hypertonic Dehydration
HYPO: 150 mEq/L
What should you watch for with isotonic dehydration?
Hypovolemic shock
What should you watch for with hypotonic dehydration?
SIDAH: Syndrome of inappropriate ADH secretion
Four causes of SIDADH
- Bacterial meningitis
- Head injury
- Tumor
- Lasix meds
** Associated with hypotonic dehydration
Indication of isotonic solution
Treatment of vascular dehydration; replaces sodium chloride
Action of hypotnoic solution
Hydrates cells, pulls fluid from vascular space into cellular space.
Action of Hypertonic solution
Draws fluid into interstitial space, leading to increased extracellular volume both in vascular and interstitial space
Action of isotonic solution
Hydrates extracellular compartment, replaces fluid volume without disrupting the intracellular and interstitial volumes
Indication of hypotonic solution
Tx Hypertonic dehydration
Indication of hypertonic solution (2)
Tx of hypotonic dehydration
Tx of circulatory collapse
What happens to vital signs with isotonic dehydration? (2)
- Elevation in Temp
* Elevation in HR-
What happens to vital signs with Hypertonic Dehydration? (2)
- Elevation in Temp
* Elevation in HR
What happens to vital signs in Hypotonic Dehydration? (2)
- Hypertension (fluid retention) Edema
* Might not see huge increase in CO
Why is Pedialyte a better choice than cola, apple juice, gatorade or chicken broth to re-hydrate? (5)
- Lower carbs than other bevs listed
- Lower sodium than chx broth
- Good source of potassium
- Most basic
- Lowest osmolarity
Serum Potassium…
- in Hypokalemia
- in Hyperkalemia
- Hypo: Less than 3.5 mmol/L
* Hyper: Greater than 5.8 mmol/L
Causes of Hypokalemia (4)
- Increased K+ excretion
- Decreased K+ intake
- Loss of K+
- Metabolic Alkalosis
Causes of Hyperkalemia (4)
- Massive cell death (sickle cell, leukemia, cancers)
- Excessive or too rapid K+ infusion
- Metabolic acidosis
- Decreased K+ excretion (renal failure)
What disorder causes hyperkalemia initially, then hypokalemia
- Diabetes (Type I): Causes HYPERkalemia initially, then HYPOkalemia because of diuresis
What are hypokalmic patients at risk for? What should you watch for?
Dig toxicity
- Bradycardia
- Cardiac arrythmias
- Vomiting
How to treat Hyperkalmia (7)
- Manage underlying condition
- Lasix (K+ wasting)
- Kayexalate
- IV Bicarbonate
- Peritoneal dialysis (if renal failure)
- Manage diet
How does Kayexalate work?
PO, binds to K+ and excreted in stool
How does IV bicarbonate work?
Drives K+ back into cell
What should you be careful of in administering K+ by IV?
*Make sure patient has good urine output before adding K+ to bag.
(80% of K+ is lost through urine, so lack of urine output could cause hyperkalemia.)
*Also, concentrated potassium causes a person to go into VTach.
What type of patient is at risk for hyperkalemia?
Burn patients
What might be the cause of a high K+ count in a baby?
Squeezing heel on a heel stick –> Lyse cells –> Inaccurately high K+ count
5% weight loss is ___ dehydration
10% weight loss is ____ dehydration
15% weight loss is ____ dehydration
Mild
Moderate
Severe
How do you calculate a patient’s dehydration weight loss?
Original weight minus present weight
Divided by original weight
Two of the following factors indicate >5% dehydration:
- Capillary refill > 2 seconds
- Absent tears
- Dry mucus membranes
- Ill appearance
Treatment of mild dehydration (<5%)
- 3 things
- Rehydrate with ORS (50mL/kg over 4 hours)
- Replace ongoing losses with ORS
- Age-appropriate diet after rehydration
Treatment of moderate dehydration (5-10%)
- 3 things
- Rehydrate with ORS (100mL/kg over 4 hours)
- Replace ongoing losses with ORS
- Age-appropriate diet after rehydration
Treatment of severe dehydration (>10%)
- Four things
- IV resuscitation with normal saline or Ringer Lactate (20-40 mL/kg for one hour) – re-assess and repeat if necessary
- Begin Oral Replacement Therapy when pt is stable
- Replace ongoing losses with ORS
- Age-appropriate diet after rehydration
What causes diarrhea?
Abnormal intestinal H20 and electrolyte transport
Acute diarrhea:
- Most common in kids under 5 years
* Less than 14 days (self-limiting)
Acute diarrhea: 5 causes
- Bacterial infection (eg food poisoning)
- Gasteroenteritis
- Abx
- Laxatives 2/2 anorexia nervosa
- Upper Resp Tract infections
Chronic Diarrhea
Longer than 14 days
5 causes of chronic diarrhea
- Irritable Bowel Syndrome
- Inflammatory Bowel Disease (Chrones, Ulcerative Colitis)
- Food allergy
- Lactose intolerence
- Malabsorption syndrome
What is the name for Chronic diarrhea in an infant? What is the cause?
Intractable diarrhea of infancy
* Acute infectious diarrhea that was not managed adequately
What is the name for chronic diarrhea in children? Most common cause?
Chronic non-specific diarrhea
** Common cause: Apple juice! (Also diet soda, food sensitivities)
Four etiologies that cause diarrhea:
- Rotavirus (immunization possible)
- Bacteria (Salmonella, Sigella, Campylobacter)
- Parasite: Cryptosporidium
- Abx
Labs to check w diarrhea:
- Urine specific gravity
- CBC
- Serum electrolytes
- Creatinine and BUN (elevated with dehydration)
