Pediatrics: Dehydration and Water Intoxication (Week 6)

Example 2 of Daily Fluid Calculation Child weighs 20kg

100 x 10 for the 1st 10 kg of body weight = 1000 mL 50 x 10 for the 2nd 10 kg of body weight = 500 mL 20 x 0 for the remaining body weight = 0 mL 1000 + 500 + 0 = 1500 mL/24 hr = 63 (62.5) mL/hr

Example 1 of Daily Fluid Calculation Child weighs 32kg

100 x 10 for the 1st 10 kg of body weight = 1000 mL 50 x 10 for the 2nd 10 kg of body weight = 500 mL 20 x 12 for the remaining body weight = 240 mL 1000 + 500 + 240 = 1740 mL/24 hr = 73 (72.5) mL/hr

Example 3 of Daily Fluid Calculation Child weighs 8.5kg

100 x 8.5 for the 1st 10 kg of body weight = 850 mL No further calculations are needed 850 mL/24 hr = 35 (35.41) mL/hr

If the body weight is 11-20kg, what is the amount of fluid per day?

1000ml + 50ml/kg > 10kg

If the body weight is 1-10kg, what is the amount of fluid per day?

100ml/kg

Add ________ mL/kg of fluid for every loose stool or episode of vomiting

10mL/kg

For severe dehydration give _______ mL/kg of oral rehydration for infants ________mL/kg for toddlers, and _________mL/kg for older children.

30 60 90

The ECF diminishes rapidly from approximately ________ of body weight at birth to less than ________ at 1 year of age

40% 30%

Water is the major constituent of body tissues, and the TBW in an individual ranges from what?

45% (in late adolescence) to 75% (in term newborn) of total body weight Preterm: 90%

The degree of dehydration has been described as a percentage of body weight dehydrated: Moderate

5% to 10% in infants and 3% to 6% in older children

For a mildly dehydrated children you will give ____________ of oral rehydration solution, where as a child with moderate dehydration maybe given _____________.

50 mL/kg 100mL/kg

What are the signs of moderate dehydration?

6% to 9% weight loss in infants 6% to 8% weight loss in children Slight tachypnea Slowed Capillary refill between 2 and 4 seconds Possible thirst and irritability Pulse slightly increased with normal to orthostatic blood pressure Dry mucous membranes and decreased tears Eyes are normal to sunken anterior fontanel on infants Oliguria (small amounts of urine)

Fever increases insensible water loss by approximately:

7 ml/kg/24hrs for each degree above 99F

What is hypertonic dehydration?

Water loss > electrolyte loss Fluid shifts from ICF → ECF; most dangerous form of dehydration Caused by increased solute load on kidneys Child becomes hyperosmotic and hypernatremic

What if the patient refuses to drink?

We will administer rehydration ORS via a syringe 2-5mls every ever 2-3mins until they are able to tolerate larger amounts. If the child has emesis, administering small amounts (5mLs) of ORS every 5 minutes or so may help overcome fluid deficit and the emesis will often lessen over time

____________ is the most important determinant of the total fluid loss in infants and young children

Weight

Signs of severe dehydration

Weight loss in infants <10% Weight loss in children 10% pulse is very increased and BP is orthostatic to shock resp rate is hyperpnea intense thirst and behavior is very irritable and lethargic Tears are absent and eyes are sunken cap refill is >4 oliguria or anuria mucus membranes are extremely dry

Can IV administration of fluids be administered immediately without knowing the exact nature of the dehydration or electrolyte levels?

Yes

Oral rehydration management consists of what?

Replacement of fluid loss over 4 to 6 hours, replacement of continuing losses, and provision for maintenance fluid requirements

_______ is a common manifestation of severe depletion of ECF volume, is preceded by _________ and signs of decreased perfusion and tissue oxygenation (by pulse ox reading).

Shock Tachycardia

Maintenance fluids contain both water and electrolyte and can be estimated from?

The child's age, bodyweight, degree of activity, and body temperature.

The rate of metabolism in infancy is significantly higher than adults. why?

They have a larger BSA in relations to the mass of active tissue up until the age of 2

When is parental therapy initiated?

Unable to ingest sufficient amount of fluid and electrolytes Meet ongoing daily physiologic losses Replace previous deficits Replace continuing abnormal losses Typically this patient will be severely dehydrated, vomiting uncontrollably, unable to drink, severe gastric distention

What is hypotonic dehydration?

Occurs when electrolyte loss > water loss Water moves from ECF → ICF to try to achieve equilibrium → worsens ECF volume loss → shock Child becomes hyposmotic and hyponatremic

What can we administer for children who are vomiting?

Ondansetron (Zofran)

How often do we assess VS for a pt with dehydration?

15-30mins

If the body weight is >20kg, what is the amount of fluid per day?

1500ml + 20ml/kg > 20kg

Infants maintain a larger amt of ECF than adult until they reach the age of ________.

2 years

Calculate the child's weight in kilograms for daily maintenance fluid requirements

Allow 100 mL/kg for the first 10 kg of body weight Allow 50 mL/kg for the second 10 kg of body weight Allow 20 mL/kg for the remaining kilograms of body weight

basal metabolic rate (BMR) is derived from standard tables and adjusted for?

Child activity, temperature, and disease state

Nurses should be alert for altered fluid requirements in various conditions. What conditions can decrease the requirements?

Heart Failure syndrome of inappropriate antidiuretic hormone mechanical ventilation after surgery oliguric (urine volume of less than 400 mL) renal failure increased intracranial pressure

Patient outcomes for fluid volume excess?

I and Os are balanced No edema No weight gain No resp distress

When can fluid intoxication occur?

IV water overload Too rapid dialysis Tap water in enemas Feeding of incorrect mixing of formula Excess water ingestion

Who is most vulnerable to becoming water intoxicated and why?

Infants Their thirst mechanismIs not well-developed therefore they're unable to turn off their fluid intake appropriately Administration of inappropriately prepared formula is one of the more common causes of water intoxication (diluting formula too much with water)

An infants BSA (body surface area) is greater than adults due to what?

Infants loose and gain more fluid than adults due to the longer GI tract and they loose more fluid through their skin

TBW is somewhat higher in males than females once maturity is reached. Why?

Mail have a higher body composition, particularly in fat and muscle content

oral rehydration therapy is effective for what typer of dehydration?

Mild to Moderate

_________ is released to promote sodium retention and conserve water in the kidneys.

aldosterone

What type of IV fluids will be administered for a pt with severe dehydration?

an isotonic solution (LRS 0.9% sodium chloride) at a rate of 20ml/kg, IV bolus or over 20 mins

Other predictors of fluid loss include....

change in LOC altered response to stimuli decreased skin elasticity and turgor prolonged cap refill >2 sunken eyes

What influence insensible water loss?

environmental heat humidity skin integrity body temp resp rate

Edema in infants and children can happen where?

extremities face perineum torso abdominal girth measurement changes may be an indicator of edema

Nurses should be alert for altered fluid requirements in various conditions. What conditions can increase the requirements?

fever vomiting diarrhea high-output kidney failure diabetes insipidus diabetic ketoacidosis burns shock tachypnea gastric suctioning phototherapy postoperative bowel surgery (gastroschisis) (a birth defect of the abdominal (belly) wall)

When to use oral rehydration?

for mild cases

In the fetus and premature baby, the largest portion of body water is contained where?

in the ECF

What s/s will be seen in a child with water intoxication?

increased urinary output decrease in sodium irritability somnolence (drowsy) HA N/V diarrhea seizures edema

Insensible losses increase when basal expenditure (the energy needed to carry out fundamental metabolic functions) ________________ by fever or hypermetsabolic state. Then, during hypometabolic states such as hypothyroidism or hypothermia the BMR ________________.

increases decreases

What are the types of dehydration?

isotonic, hypotonic, hypertonic

The degree of dehydration has been described as a percentage of body weight dehydrated: Mild

less than 3% in older children or less than 5% in infants

What is isotonic dehydration?

loss of water with preserved normal effective osmolality of body fluids..

A loss of 50ml/kg is considered _______ A loss of 100 ml/kg is considered _________

mild severe

What should the outcomes be after rehydration is complete

moist mucus membranes sodium and potassium stable voiding (>1ml/kg/h) cap refill of 2 sec or less skin turgor brisk I and Os are balanced

The degree of dehydration has been described as a percentage of body weight dehydrated: Severe

more than 10% in infants and more than 6% in older children

In a ___________________, about 50% of their body fluid is contained within the ECF whereas 30% of _______________ body fluid is contained in with the ECF.

newborn toddlers

Children who ingest excessive amounts of electrolyte - free water develop a decrease in what?

sodium along with CNS symptoms.

ORS enhances and promotes the reabsorption of?

sodium and water

What is insensible water loss?

the amount of body fluid lost daily that is not easily measured, from the respiratory system, skin, and water in the excreted stool.

The minimal amount of fluid loss from the body that can occur is referred to as?

the obligatory water loss. This sets a figure for the minimal amount of fluid intake that is required to maintain total water balance.

Maintenance water requirement means what?

the volume of water needed to replace obligatory fluid loss

Infants are more likely to become dehydrated than adults because?

their kidneys are unable to dilute or or concentrate urine yet. They are more likely to become dehydrated when given concentrated formulas or over-hydrated when given free water or dilute formula

What are some disturbances of select fluid and electrolyte balance?

water depletion water excess hypo and hyper natremia hypo and hyper kalemia hypo and hyper calcemia

Accurate measurements of _________, and ________ and ________ are extremely important

weight, and fluid intake and output

When does dehydration occur?

when the total output of fluid exceeds the total intake, regardless of underlying cause.