Distribution of Body Fluids in Pediatrics

Fluid & Electrolyte
GI Alterations

Nursing 355

Maria Rubolino-Gallego

Distribution of Body Fluids in Pediatrics

n Children are more vulnerable than adults to changes in electrolyte balance

n Sensible water loss vs. insensible water loss

n Infants have a higher % of water in their extracellular fluid

n Approx. 40% of body water is in the ECF in a neonate compared with 25% at age 2 and 20% in adults

n Infants and young children unable to verbalize thirst

n Water is located in two major compartments

- Intracellular

- Extracellular

Proportion of water contents:

90% of premature infants

75-80% of full-term infants

60-65% of preschool children

55-60% of adolescents and adults

Review of Mechanisms of Fluid Movement

n Hydrostatic pressure

n Osmotic pressure

n Diffusion-mvmt of molecules from higher conc. to regions of lesser conc.

n Active transport

Water Balance in Infants

n Surface area – greater amounts in premature infants

n Metabolic rate – greater in infants

n Kidney function –immature and unable to concentrate urine

n Fluid requirements – ingest and excrete a greater amount of fluid per kg of body weight

n Little fluid reserve

Fluid and Electrolyte Disorders

n Hyponatremia – less than 150mEq/L

n Causes of this:

n Sxs: HA, dizziness

n Hypernatremia – over 150mEq/L

n Causes of this:

n Sxs: Thirst, oliguria

Assessment of Fluid/Electrolyte Disturbances

n Tissue turgor –

– Poor with dehydration

n Mucous membranes –

– dry to slightly moist

n Vital signs – afebrile to febrile, tachycardia

n Weight changes –

– loss is related to fluid defici

– gain is related to edema or ascites

n Urine volume and concentration – usually diminished to oliguria depending on the severity of fluid deficit

n Specific gravity

– Low due to: fluid excess, sodium deficit

– High due to: fluid deficit, sodium excess

n Sensory changes

– Tingling in fingers and toes

– Abdominal cramps

– Muscles cramps

– Light-headedness

– Nausea

– Thirst

n Neurological changes:

– Hypotonia

– Flaccid

– Weakness

– Hypertonia

– Tremors

– Cramps

– Twitching

Fontanel's – what happens to them?

Dehydration

n Isonatremic – water and electrolytes lost in equal amounts and sodium serum levels is normal (135-145 mEq/L)

n Most common type

n Hyponatremic – Loss of electrolytes greater than water loss, sodium conc. of less than 130

n Hypenatremic –Loss of water greater than electrolytes loss, sodium serum concentration is above 150

n Causes-

Degree of Dehydration

n Mild – 4-5% loss of body weight; fluid volume loss of less than 50 ml/kg

n Moderate – 6-10% loss of body weight; fluid volume loss of 50-90 ml/kg

n Severe – 10% or more loss of body weight; fluid volume loss of 100 ml/kg or more

n Determine percent of dehydration

n 1 ml of body fluid is equal to 1 gm of body weight

Nursing Responsibilities in Children

n History – history of acute and chronic fluid loss, weight of child, stools, vomitus, diapers (wet/stool)

n Clinical observations – lethargy, confusion, or seizures, cry, skin color, fontanel, pulse, respirations, vital signs, tears, mucous membranes

n Laboratory values –

– check sodium, potassium, urine (including specific gravity), calcium

n Monitor I/O’s accurately

n Monitor child’s weight

n Oral Rehydration Therapy (ORT): preferred TX with mild to moderate dehydration

n Examples include Pedialyte, Infalyte, Rehydralyte

n ?Gatorade - high percentage of sugar and carbohydrates

n ORT - 1 teaspoon of ORT every minute to 120ml (4 ounces) every hour

n NEVER GIVE PLAIN WATER WITHOUT ELECTROLYTES

n May lead to water intoxication and edema

n ?BRAT diet, clear liquids etc….

Severe Dehydration
Unable to take fluids

n Parenteral fluid and electrolyte therapy should be initiated

n Goal: prevent shock

n LR or NS is fluid of choice

n Maintenance therapy: add dextrose to the solution/ potassium may also be added

n Potassium may be added once urine is adequate

n Always check dosage – may lead to lethal dose in a child, never IV push, give at a rate no faster than 1 mEq/kg/hr)

Assessment

n History

n General Observation

n Clinical Observation

n Specific tests/procedures

– I/O

– Weight

– Stool, vomitus -frequency, type, amounts, consistency

– Urine output and specific gravity

– Sweating

– Skin

– Fontanel

– VS

– Blood tests including CBC, Electrolytes BUN/Creatnine, blood cultures

Diarrhea

n One of the most common disorders in children

n US, children younger than 5 years old experience 20-35 million episodes of diarrhea per year

n Increase in the frequency, fluidity, and volume of stools

n May be acute or chronic

n Typically called gastroenteritis when caused by infection

n Viral gastroenteritis makes up for approx. 80% of all cases

n Different causes: Bacterial vs. viral vs. parasitic

n Can lead to dehydration, shock, electrolyte imbalance

n Signs/symptoms: skin texture, abdominal cramps, stool changes, heart rate changes, respiratory rate changes

Rotavirus

n Rotavirus - , fecal-oral route, the peak incidence occurs between 7 and 15 months of age, with approximately 0.8 episodes per child per year

n Children become most susceptible after 6 months of age when the protection afforded by maternal antibodies wanes

n By 15 months of age many have developed some protection after primary infection

n Almost all children get rotavirus at least once before they are three years old

Management of Diarrhea

n Restore fluids and electrolytes

n Handwashing

n Avoid beverages high in carbohydrates (Gatorade)

n Oral Rehydration Therapy begin within first 24 hours

n Early reintroduction of feeding

n Rice cereal for younger children

n Breast milk – evidence that it may reduce the duration of diarrhea by approx. half a day

n Eat every 3-4 hours

Management

n Bland foods: complex carbohydrates

– Rice

– Wheat

– Potatoes

– Yogurt

– Cooked vegetables

– Lean meats

– Avoid BRAT diet

Vomiting

n Forcible ejection of stomach contents through the mouth

n Isolated incidents are of little concern, but persistent, prolonged vomiting can be serious

n Occurs frequently in children

n Causes: infections, motion sickness

n Diagnostic tests (if severe): CBC, electrolytes, blood cultures, glucose level, urine analysis

n Types:

– Greenish – bile or obstruction

– Fecal odor – lower intestinal obstruction or peritonitis

– Bright red blood- indicates that the blood has not been in contact with the gastric juices

Treatment of Vomiting

n Detecting and treating the underlying cause

n ORT

n Monitor electrolytes

n Monitor body weight

n IV therapy if severe or prolonged in neonates or young infants

n Antiemetics – Tigan, Phenergan

GI System

n Swallowing is not under voluntary control until 6 weeks

n Stomach capacity

– Newborn 10-20 ml

– 1 week 30-90 ml

– 1 month 90-150 ml

– 1 year 210-360 ml

– 2 years 500 ml

– Adult 200-3000 ml

Prenatal Development

n Gut is formed from the endoderm in the first 4 weeks of embryonic development

n Anatomically development is completed at birth

n Physiologically the neonates GI tract is immature

Disorders of Absorption and Digestion

n Lactose Intolerance

– Absence or deficiency of enzyme (lactase found in the small intestine)

– Unknown cause

– Increased incidence in 50-90% of Asian, Arabs, Jews, African American, and Southern Europeans

– Sxs: frothy diarrhea, abdominal distention and cramping, excessive flatus

– Usually seen by age 3

– Dx with stool which has 1+ or greater sugar or presumptive diagnosis

– Tx with lactose free diet (lacto free or soy formula)

Gastroesophageal Reflux
GERD

n Regurgitation of gastric contents back into the esophagus

n Causes: cerebral palsy, Down syndrome, head injury, obesity, hiatal hernia, also a normal phenomenon

n Typically resolves by 1-2 years of age

n Boys more affected than girls

n Preemies more affected than term infants

GERD

n Pathologic GERD - child can experience weight loss, failure to thrive, abdominal pain, irritability

n DX: Barium swallow, Upper GI study, pH studies, Ultrasound

n Treatment: Dietary alterations, positional changes, medications, surgery

GERD

n Diet: Small, frequent feedings of predigested formulas, frequent burping, thickened formula

n Positioning: 30 degree head elevated prone or right side-lying

n Medications: FDA has not approved them but used frequently with pathologic jaundice: H2 receptor antagonists, PPIs, protonics

Celiac Disease

n The inability to digest gluten

n Failure to thrive by 9-12 months of age

n Gluten in the protein found in wheat, rye, barley, oats

n 1 in 1000 live births in the US

n 80-90% of children have the genetic marker HLA-B8, a known leukocyte antigen complex on chromosome 6

n Sxs: Diarrhea, failure to grow (below 25th percentile), abdominal distention (ascites), vomiting, anemia, muscle wasting

n Usually not seen until at 3-6 months of age

n Dx: serum antigliadin antibody of strip AGA test, single drop of blood and ELISA test is used

n Diagnosis supported with change in diet

n Tx with lifelong dietary management of gluten-free diet

Constipation

n Infrequent and difficult passage of dry, hard stools (assess frequency, intensity, and duration)

n A major concern is encopresis or fecal incontinence

n Symptoms: absence of stool, abdominal pain, cramping

Encopresis

n Soiling usually affects ages 3-7 years

n More likely in boys

n Repeated and involuntary defecation in a child with a normal rectum and colon

n Children often complain that soiling occurs without warning

n Many causes: diet, dehydration, decreased exercise, emotional stress, certain medications, pain from anal fissures, and excessive milk intake

n Dx – enlarged rectum on X-ray and also history

n Enemas to decrease impaction but need to limit this tx until after diagnosis is established

n Tx: diet, exercise

n Stool softeners

n Diet changes

n Increase water, fiber

n Bathroom for 5-10 minutes within 20-30 minutes after eating

n Positive reinforcement, behavioral charts

Congenital Aganglionic Megacolon or Hirschsprung’s Disease

n Absence of ganglion cells in the rectum, cannot pass stool through the rectum efficiently

n More often males than females (4:1)

n Higher incidence with Down’s syndrome

n Can vary from mild to severe (if severe, requires surgery)

n Newborn: mec? in first 24 hours of life

n Sxs: Delayed passage or absence of meconium stool in newborn, chronic constipation and small stool or ribbon-like stools, constipation that has been persistent since the neonatal period

n Tx:stool softeners, rectal irrigations, surgery

Irritable Bowel Syndrome

n Increased motility that leads to spasms and pain

n Stress and emotional factors are thought to be the most common cause

n Infants related to lactase deficiency

n Age 16 to 20 months, school age and adolescents – most common in toddlers and adolescents

n Girls affected more than boys

n Tends to occur in families with a history of other bowel disturbances

n Disorganized contractility leading to diarrhea and constipation

n Dx: Elimination of other major GI conditions

n Management: to reduce symptoms, well balanced, moderate fiber diet

n Avoid carbonated drink beverages

Intussesception

n Invagination of a section of the intestine into the distal bowel that causes obstruction

n 3 months to 6 years – generally affects young children and infants, more common in children with celiac disease or cystic fibrosis

n Cause: unknown, contributing factors: viral infections

n 1 to 4 per 1000 births

n Pediatric emergency

n Sxs: paroxysms of pain, palpable, abdominal mass, vomiting, bleeding, or current jelly stools, sausage shaped abdominal mass

n Dx:Ultrasound, barium enema

n Tx: Hydrostatic reduction with barium or air enema or ultrasound guided enema (if fails, then surgery)

Appendicitis

n Inflammation and infection of the veriform appendix (at the end of the cecum)

n Most common in early adolescence and early adulthood

n In most cases, no known cause

n Uncommon for children but if occurs, most often leads to perforation due to the difficulty in diagnosing

n Sxs:Pain progressing in intensity, McBurney’s, rebound tenderness, N/V, anorexia, diarrhea, constipation, fever, chills

n Dx: Increased WBC

n Tx: Appy, NPO, pain control, antibiotics, no heat, no laxatives, no enema

Inflammatory Bowel Disease

n Chronic inflammation condition of the small or large intestine

n Includes 2 distinct conditions: Chron’s and ulcerative colitis

n Ulcerative colitis – affects only the colon

n Chron’s – can affect all of the GI tract

n Unknown cause, several triggers identified

n Dx: colonoscopy, barium enema

n Sxs: Weight loss, diarrhea, vitamin deficiency, anemia

n Tx: medication – anti-inflammatory, antibiotics, immunosupressive therapy, ASA, steroids

n Meds: Remicade – binds to tumor necrosis factor and will reduce inflammation

n Malnutrition is a common problem

n Remission and exacerbations are common

Necrotizing Enterocolitis
NEC

n Most common GI tract disorder in the neonate

n Necrotic lesions of the mucosa of the small and large intestine

n 1% - 15% of all infants admitted to NICU

n Incidence increases with decreasing gestational age

n S/S: apnea, bradycardia, temperature instability, emesis, bloody stools, visible bowel loops, abdominal tenderness

NEC

n DX: Xray reveals dilated bowel loops, air within the intestinal wall

n Labs: increased or decreased WBCs, decreased platelets, electrolyte imbalances

n Prevention: Breast milk (IgA and IgG), oral immunoglobulin

n Tx: decompression of the GI tract with NG tube, control sepsis, IV fluids, TPN

Pyloric Stenosis

n Circular area of muscle surrounding the pylorus hypertrophies and obstructs gastric emptying

n Most common surgical disorders in early infancy

n 3 in 1000 births

n Males more than females

n Full term infants are affected more often

Pyloric Stenosis

n Progressive projectile, nonbilious vomiting in a previously healthy infant

n Movable, palpable, firm, olive-shaped mass is felt in the RUQ

n DX: vomiting history, Xray, Ultrasound

n TX: Pyloromyotomy (release the obstruction)

Infectious Gastroenteritis

n Caused by a group of viruses, bacteria, or parasites

n High-risk groups – preschools, daycare, long-term care facilities

n Giardia – most common in daycare settings

n Rotavirus – most common in infants and young children

n Most common outpatient infectious diseases in children

n Peak in the summer

n Transmission- fecal-oral, food or water born

n Sxs: diarrhea, vomiting, abdominal pain, fever

n Tx: replace fluids correctly (IV or PO)

Biliary Atresia

n Obstruction or absence of the extrahepatic bile ducts

n Problem originates in the prenatal period (toxins, viruses, chemicals?)

n 1 in 10,00-20,000 births

n Will lead to cellular damage in the liver and eventually to liver failure

n Slightly higher incidence in females over males

n Sxs: child is healthy at birth, light colored stools, hepatomegaly

n Dx:LFTs, PT, PTT

n Tx: hepatic portoenterostomy to allow bile to drain from the liver, liver transplant

Viral Hepatitis

n Caused by different viruses

n Acute or chronic inflammation of the liver

n Hep A – common in daycare settings, highly contagious

n Hep B – perinatal transmission, blood transfusion, exposure to contaminated body fluids (can survive in the dry state for 1 wk)

Hep A

n Sxs: in A are often asymptomatic or mild

n Non-specific: anorexia, malaise, fatigability

n No specific treatment

n Handwashing

n Vaccine developed for this

Hep B

n Sxs

– Anicteric phase (without jaundice):

§ Anorexia

§ N/V

§ RUQ pain

§ Fever

§ Malaise

§ Depression

§ Fatigue

§ Irritability

§ Lasts 5-7 days

Hep B

n Sxs

– Icteric Phase (jaundiced)

§ Jaundice

§ Urticaria

§ Dark urine

§ Light colored stools

Hep B

n Hep B vaccine in infancy

n Recommended to begin vaccination series in the hospital as a newborn