Simple sugars increases the osmotic effect in the intestine by pulling water into the colon, thereby increasing diarrhea and subsequent fluid/electrolyte loss Drinks high in glucose: apple juice, sodas, jello water.
Potassium is only added to an IV after the patient has voided to avoid hyperkalemia in a child with little or no urinary output
9yr old wt 20 Kg = 1500ml/day 6 mo old wt 8Kg= 800ml/day 36mo old wt. 18 Kg= 1400ml/day 3yr old wt 28Kg=1660ml/day 18yr old wt 50Kg= 2100ml/day Adult > 50Kg= 2-3L/day
Chvostek’s Sx: p 755 tap the skin lightly in front of the ear (over the facial nerve), if the corner of the mouth draws up, d/t muscular contraction, + Chvostek’s Sx. Trousseau’s Sx: + if carpal spasm after BP cuff inflated ~ 3min.
3 paragraphs of text that review this concept and pull the content together with clinical application: 1) risk factor assessment 2) exam several body systems: cardiovascular, respiratory, neurological 3) look for factors that alter intake, retention, and loss of fluids and electrolytes 4) consider growth and development to realize problems most common to the age group. 5) clinical assessment: wt, fluid balance, vascular volume (BP, HR), interstitial volume (edema?), mentation, DTR’s, muscle irritability, GI function, cardiac rhythm, assess electrolyte levels.
Alterations in Fluid,
ECF/ICF ratio varies with age
Neonates and infants have proportionately
larger ECF vol
Infants: high daily fluid requirement with
little fluid reserve; this makes the infant
vulnerable to dehydration.
Fluid Loss; Infants and <2yr.
excretion is via the urine, feces, lungs and
have greater daily fluid loss than older child
more dependent upon adequate intake
greater about of skin surface (BSA),
therefore greater insensible loss.
respiratory and metabolic rates are higher
therefore, dehydrate more rapidly
Mechanism to Restore balance
kidney: conserves water, regulates
<2yr kidneys immature
less able to conserve or excrete water and
greater risk for acid/base imbalances
Will use the SG norm: 1.005-1.015
Fluid Volume Imbalances
Dehydration: loss of ECF fluid and sodium.
Caused by: vomiting, diarrhea, hemorrhage,
burns, NG suction.
Manifested by wt loss, poor skin turgor, dry
mucous memb., VS changes, sunken fontanel
Fluid overload: excess ECF fluid and excess
interstitial fluid volume with edema.
Causes: fluid overload, CHF.
Manifested by wt.gain, puffy face and extremities,
How can the nurse determine if the child is
mildly dehydrated vs moderately
Mild Dehydration: by history.
hard to detect because the child may be
alert, have moist mucous membranes and
normal skin turgor.
Wt loss may be up to 5% of body weight.
The infant might be irritable; the older child
might be thirsty
vital signs will probably be normal
Capillary refill will most likely be normal
Urine output may be normal or sl less
dry mucous membranes; delayed cap refill
>2 sec; Wt loss 6-9% of body weight
irritable, lethargic, unable to play, restless
decreased urinary output: <1ml/kg/hr; dark
urine with SG > 1.015 (in child >2yr)
HR increased, BP decreased. Postural vital
wt loss > 10% body weight
rapid weak pulse with BP low or
undetectable; RR variable and labored.
dry mucous membranes/parched; sunken
decr or absent urinary output.
Cap refill >4sec
Types of Dehydration and Sodium
Sodium may be:
Isotonic Dehydration or Isonatremic
Loss of sodium and water are in proportion
Most of fluid lost is from extracellular component
Serum sodium is normal (130-150mEq/L) Harriet
Lane Handbook, 2000.
Most practitioners consider below 135 and above 148 a
more conservative parameter (138-148)
Most common form of dehydration in young children from
vomiting and diarrhea.
Hypotonic or Hyponatremic
Greater loss of sodium than water
Serum sodium below normal
Compensatory shift of fluids from extracellular to
intracellular makes extracellular dehydration
Caused by severe and prolonged vomiting and
diarrhea, burns, renal disease. Also by treatment
of dehydration with IV fluids without electrolytes.
Hypertonic or Hypernatremic
Greater loss of water than sodium
Serum sodium is elevated
Compensatory shift from intracellular to
extracellular which masks the severity of
water loss (dehydration) delaying signs and
symptoms until condition is quite serious.
Caused by concentrated IV fluids or tube
Common viral form of diarrhea
All ages but 3 mo-2yrs most common
Virus remains active;
10 days on hard, dry surfaces
4 hrs on human hands
1 wk on wet areas
Incubation period 1-3 days
Symptoms: mild/mod fever, stomach ache,
frequent watery stools (20/day)
Treatment: prevention! Hand washing and
isolation of the infected child.
Fluid rehydration for diarrhea, advanced to
bland diet for older children
Breast milk for the infant who BF
Clinical Management for
Blood may be drawn to assess electrolytes,
BUN and Creatinine levels
an IV may be placed the same time
Oral Rehydration Solution is the treatment
of choice for mild-moderate dehydration
1-3 tsp of ORS every 10-15min to start (even if
50ml/Kg/Hr is the goal for rehydration.
Why are drinks high in glucose
avoided during rehydration?
Answer to why high glucose drinks are
Recommended foods during
starches, cooked fruits & vegetables,
soups, yogurt, formula, breast milk.
BRAT diet used to be recommended, but
recent research has shown no difference
than return to normal diet with some
attention to lactose containing foods,
depending upon the child’s response.
Used for severe dehydration or in the child
who will not/cannot tolerate ORS
Half 24hr maintenance plus replacement
given within first 6-8hr (in ER) to rapidly
expand the intravascular space. Usually a
normal saline bolus.
slower IV rate for the remainder of the first
nurse records IV vol infused hourly
Rehydration and IV solution
Why is the child initially rehydrated with a
normal saline bolus and not an IV solution
Answer to rehydration and IV solution
Which of the following IV solutions
D5 ½ NS
All but D5 W
See IV solutions table B & B p. 733
Calculation of intravenous fluid
see pg 735 B&B, Box 23-5.
For the 1st 10 Kg, replace at 100ml/Kg
for the second 10 Kg, replace at 50ml/Kg
for >20kg, replace at 20ml/Kg
Example of Maintenance Fluid
Your patient is a 10 yr old weighing 35 Kg.
You want to determine this patient’s 24hr
maintenance fluid needs:
for the first 10 Kg give 100ml/Kg = 1000ml
for the second 10 Kg: 50ml/Kg = 500ml
for the remaining 15 Kg (35-20Kg) , replace
at 20 ml/Kg = 20 (15) = 300ml
1000 + 500+ 300= 1800ml/day.
How much fluid should this patient get
1800 ml / 24 hrs = 75 ml/hr.
Therefore, if the patient were NPO and not
taking in fluids from any other source, the IV
should be running at 75ml/hr.
If there is a deficit that also needs to be
replaced, the IV rate may be slightly higher
for a defined period of time.
If the patient is receiving fluids from other
sources, these need to be accounted as well
Practice Problems for Calculating 24hr
Fluid Maintenance and the hourly IV rate
A 9 yr old patient who weighs 20 Kg.
A 6 mo old baby who weighs 8 Kg
An 24mo old toddler who weighs 18 Kg
A 3 yr old preschooler who weighs 28 Kg
An 18 yr old who weighs 50 Kg
assess dependent limbs if ambu or sacrum
ascites; periorbital edema; rings too tight
pitting edema for degree of swelling
daily wt and strick I and O
elevation/change position Q2hr/ protect skin
distraction to deal with discomfort and
limitations of edema.
Electrolytes usually gained and lost in
relatively equal amounts to maintain
Imbalance caused by:
Abnormal route of loss (vomiting/diarrhea) can
disturb electrolyte balance
Disproportionate IV supplementation
Disease states: renal dis.
Excess serum sodium in relation to water
Too concentrated infant formula
Not enough water intake
Clinical manif: thirst, lethary, confusion
Seizures occur when rapid or is severe.
SG concentrated 1.020-1.030
Lab test: serum sodium
Treatment: hypotonic IV solution
Excess water in relation to serum sodium
Most common sodium imbalance in
Infants vulnerable to water intoxication:dilute
form, excess pool water, poorly developed thirst
mech so cont to drink and can’t excrete excess
Clinical manif: decreased level of
consciousness d/t swelling of brain cells.
Anorexia, headache, muscle weakness,
decreased DTR’s, lethargy, confusion or coma.
Seizures occur when rapid or severe.
SG dilute: 1.000-1.0005
Lab tests: serum sodium
Treatment: hypertonic solution.
Excess serum potassium
excess K intake from IV overload, blood
transfusion, rapid cell death (hemolytic crisis,
large tumor destruction from chemo rx, massive
trauma, metabolic acidosis from prolonged
diarrhea and in DM when insulin levels are low
Insulin drives K back into the cells
decreased K loss from Renal insufficiency
Clinical manif: all are related to muscle dysfunction:
hyperactivitiy of GI smooth muscle: intestinal cramping and
Weak skeletal muscles
Cardiac arrhythmias (tachycardia, prolonged QRS, peaked T
waves: also AV block and VTach).
Lab test: serum potassium
Treatment: correct underlying condition (take K out of the IV)
dialysis (peritoneal or hemo), Kayexalate (po or enema), K
wasting diuretics, IV calcium, bicarbonate, insulin and glucose.
Low potassium diet.
Decreased serum potassium
Causes: diarrhea and vomiting, ingestion of
large amts black licorice, diuretics, osmotic
diuresis (glucose in urine as in DM), NPO
without K replacement in IV, NG Sx,
Also in nephrotic syndrome, cirrhosis, Cushing
Syndrome, CHF (to be covered elsewhere)
Clinical manif: muscle dysfunction
Slowed GI smooth muscle resulting in abdominal
distention, constipation and paralytic ileus
Skeletal muscles are weak; may effect respiratory
Cardiac arrhythmias: hypokalemia potentiates
Lab test: serum potassium
Treatment: oral and/or IV potassium, diet rich in
Needs vit D for efficient absorption; most of Ca is
stored in the bones.
Causes: bone tumors that cause bone
destruction, chemo rx release Ca from the bones;
immobilization causes loss from the bones
(usually excreted) but if kidneys can’t clear it,
hypercalcemia results, increased intake (milk-
Clinical manif: Ca imbalances alter
neuromuscular irritability with non-specific
Constipation, anorexia, N/V, fatigue, skeletal muscle
weakness, confusion, lethargy.
Renal calculi, cardiac arrhythmias
HyperCa increases Na and K excretion leading to polyuria
Rx: serum Ca, Ionized Ca, fluids, Lasix, steroids, dialysis.
Decreased serum calcium
Causes: decreased intake of Ca and/or Vit D
(adolescents are vulnerable d/t fad diets and the
deficit cannot be made up later, increasing risk for
Limited exposure to sunlight, premature infants and dark
skinned people at increased risk to inadeq. Vit D and
therefore decreased Ca absorption.
Parathyroid dysfunction, multiple transfusion (Citrate binds
Calcium), steatorrhea (as in pancreatitis and Cystic
Fibrosis) binds Calcium in the stool.
Clinical Manif:acute situation related to increased
muscular excitability: tetany. +Chvostek’s Sx, +
In children: Twitching, cramping, tingling around
the mouth or fingers, carpal/pedal spasms.
In infants: tremors, muscle twitches, brief tonic-
clonic seizures, CHF.
Laryngospasm, seizures and cardiac arrhythmias
in severe situations.
Hypocalcemia (cont 2)
In children and adolescents, chronic
hypocalcemia more common, manif. By
Lab tests: serum Ca; bone density study
Rx: oral and/or IV Ca, Ca rich diet
Excess in Mg.
Imbalances characterized by
Causes: impaired renal function, Mag
Sulfate given perinatally to treat eclampsia,
increased use of laxatives, enemas,
antacids, IV fluid additives.
Decreased serum Mg.
Stored in cells and bones
Causes: prolonged NPO without
replacement, chronic malnutrition, chronic
diarrhea, short bowel syndrome,
malabsorption syndromes, steatorrhea,
multiple transfusions, prolonged NG Sx,
Clinical manif: increased neuromuscular
excitability (tetany). Hyperactive reflexes,
skeletal muscle cramps, twitching, tremors,
cardiac arrhythmias, seizures.
Lab: serum Mg along with Ca and K.
Rx: po/IV Magnesium admin and treating
underlying cause of imbalance.
Critical Thinking: Clinical Evaluation
of Fluid and Electrolyte Imbalance
B & B p. 757
How can you evaluate children
appropriately for fluid and electrolyte
imbalance without thinking through the
clinical manifestations of every possible
disorder, one after the other?
Fluid and Electrolyte Worksheet
Use the fluid and electrolyte worksheet to
help review some of the major concepts of
fluid and electrolyte imbalance.
Acid Base Balance
normal arterial blood pH: 7.35-7.43 (in
Acidosis < 7.35 : too much acid
Alkalotic > 7.43 : too little acid
pCO2 reflects carbonic acid status: 40 +- 5
HCO3- reflects metabolic acid status:
24 +- 4
caused by decr respir effort
build up of CO2 in the blood
pH decr or normal; pCO2 incr.
Symptoms manifested: confusion, lethargy,
HA, incr ICP, coma, tachycardia,
Management of Respiratory
Incr ventilatory rate
Clinical Conditions that cause
conditions associated with decreased
respiratory drive, impaired gas
exchange/air trapping, ie:
head trauma, general anesthesia, drug
overdose, brain tumor, sleep apnea,
mechanical under ventilation, asthma,
croup/epiglottitis, CF, atelectasis, MD,
caused by hyperventilation
CO2 is being blown off
pH incr : pCo2 decr
Symptoms: dizziness, confusion,
neuromuscular irritability, paresthesias in
extremities and circumoral, muscle
cramping, carpal or pedal spasms.
Management of Resp. Alkalosis
First determine if oxygenation is adequate,
if not, you don’t want to slow the RR.
Determine the cause and correct it:
Causes of hypervent: hypoxemia, anxiety,
pain, fever, ASA toxicity,
meningitis/encephalitis, Gram - sepsis,
Ipecac is no longer recommended for
treatment of ingestions.
caused by a loss of bicarbonate (HCO3)
therefore, is an incr of acids in the blood
pH decr or moving towards normal
pCo2 decr ; HCO3 decr
Symptoms: Kussmaul respirations = incr
rate and depth as compensation
confusion, hypotension, tissue hypoxia,
cardiac arrhythmias, pulmonary edema.
Management of Metabolic Acidosis
Identify and treat underlying cause
In severe case may give IV NaHCO3 to incr
pH, or insulin/glucose.
Causes of MA for gain of acid: ingestion of
ASA, antifreeze, oliguria, RF, HAL, DKA,
starvation or ETOH KA, lactic acidosis
Loss of HCO3: maple syrup urine disease,
caused by loss of H+ or HCO3 retention
HCO3 incr with probable incr in pH, incr
Symptoms:weak, dizzy, muscle cramps,
twitching, tremors, slow shallow resp.,
Management of Metabolic Alkalosis
correct underlying cause; facilitate renal
excretion of HCO3.
admin NS, K+ if hypokalemic, replace loss
of fluids, prec for Sz, monitor I and O and
Causes: prolonged vomiting, ingestion of lg
quantities of bicarb, antacids, loss of NG
fluids, hypokalemia from prolonged diuretic
use, multiple blood transfusion with citrate.
ABG Basic (Uncompensated)
Resp Acidosis: low pH and high PaCO2
Resp Alkalosis: incr pH and low PaCO2
Metab Acidosis: low pH and nl PaCo2;
Metab Alkalosis: high pH; nl PaCO2 ; high
ABG Analysis with Compensation
Resp Acidosis: HCO3 will incr, pH will
approach nl; PaCO2 will still be increased
Resp Alkalosis: HCO3 will decr, pH will
approach nl; PaCO2 will still be decreased
Metab Acidosis: PaCO2 will decr, pH will
approach nl; HCO3 will still be decreased
Metab Alkalosis: PaCO2 will incr, pH will
approach nl; HCO3 will still be increased