Endocrine & Metabolic

• The endocrine system is composed of
• various tissues that produce and secrete hormones

• Feedback control is how the tissues know
• when and how much hormone to release

• Negative feedback—when the system detects
• increasing amounts of hormone and limits their release

• Positive feedback when the system detects
• hormone levels are too low and secretes the hormone

Stimulate and regulate hte actions of other tissues-- the target tissues.

Autonomic nervous system.

The hypothalamic-pituitary axis.

• It is less developed at birth than any other body system 
• Hormonal control of many body functions is lacking until 12 to 18 months of age 
• as a result infant ma manifest imbalances in the concentration of fluids electrolytes amino acids glucose and trace substances.

The target gland is stimulated ot secrete additonal hormon.

Anterior and posterior lobes.

Adrenocorticotropic hormone (ACTH)

Thyroid-stimulating hormone (TSH)

Follicle-stimulating hormone (FSH)

Luteinizing hormone (LH)

Growth hormone (GH)

Prolactin

ACTH, TSH, LH, FSH

IT stores and releases antidiureteic hormone (ADH) and oxytocin. Which are synthesized by the hypothalamus.

ADH and oxytocin

THe childs age and stage of puberty.

• Height
• Weight 
• and sexual development using the Tanner stages

• Islets of Langerhans
• Beta cells
• responsible for insulin

Cortisol

lAldosterone

lAndrogen

lEpinephrine

lNorepinephrine

• The SGA babies 
• 1.3-3 per 1000 births

• May
• be asymptomatic

• lJittery,
• poor feeding, lethargy, seizures

• lApnea,
• hypotonia

• lHigh
• pitched cry

lBradycardia

lCyanosis

• lTemperature
• instability

• When asymptomatic treat with breast milk,
• formula or D5W po

lIf lethargic, may require gavage feedings

• lIf glucose < 20-25 mg, IV bolus of D10
• W at 2 ml/kg and continuous IV replacement

lGlucose goal—50 mg or above

• lIf condition persists, a total workup is
• indicated

• Total
• serum calcium below 7.0

• lAt
• risk are babies born to diabetic mothers, SGA, or with history of birth
• asphyxia

• May
• be asymptomatic

lTwitching

lTremors

lIrritable

lJittery

• lEKG
• changes

• lRare
• seizures

• Formula
• feeding may correct

• Oral
• or parenteral supplement

• IV
• calcium is very irritating to veins

Genetic metabolic disorder that results in CNS damage from toxic levels of phenylalanine in the blood.

An autosomal recessive disorder and is manifested in the homozygote (individual who inherited tow identical genes foe a specific trait).

Metabolic alterations begin immediately but signs do not appear until 3 MONTHS

Digestive problems with vomiting!! they may also have a musty or mousy oder to the urine also infatile eczema, hypertonis, hyperactive.

Hypopigmentation of hair skin and irises (commonly blond with light blue eyes) also MR is a long term consequence.

Intellectual impairment (MR)

• Newborn
• screening

• lIf
• baby is less than 3 days old, may have a false negative test

• lPositive
• results are presumptive

For fear of the infant will not have in follow up.

Because any earlier might have a false negative result.  If it is done before 3 days than you should repeat at several days old.

• Guthrie test
• chromatographic 
• fluorometric assay

Immediate restriction of phenylalanine

lLife-long dietary restrictions

• lRESTRICTS protein, avoids meats, cheese,
• fish, eggs, milk, and legumes.

lLow protein bread, cereal, and pasta

• lStaples are vegetables, starches, and
• fruits

• lMay take phenylalanine-free protein
• supplements

Serum Phenylalanine level at 2 to 6 in infants and young children.  2 to 15mg/dl in children older than 12 years

A medication that can lower blood phenylalnine levels.

• Adrenal
• cannot produce glucocorticoid

• lProduces
• androgen excess resulting in decreased glucocorticoid and increased androgen

• lResults
• in ambiguous genitalia of newborn

• l“Salt
• wasting” or low sodium

a defect in the enzymateic pathway of adrenal steroid productions, Diminished glucocorticod production prompts increased ACTH produciton further increasing adrenal androgen excess

• Life-long
• glucocorticoid replacement

• lMay
• require mineralocorticoid with salt wasting features

• lIf
• the child is sick, the replacement dose may be increased and require a
• different mode of delivery

• lGirls
• may require reconstructive surgery for genitalia

• lOngoing
• bone density evaluations

Will waste salt through the kidneys.  "Salt-wating" crissis.

• Hypovolemia
• Hyperkalemia
• 21-hydroxylase deficiency.

Advanced bone age with ultimatie adult short stature.

Elevated 17-hydroxyprogesterone

Teh glucocorticoid dosage is usually double or tripled when the child is ill, has a broken bone or is undergoing a surgical procedure.

admin glucocorticoid parentaerally

Liner growth and signs of early puberty.

a condition in which teh thyroid gland does not produce sufficent thyroid hormoneto meet the bodys metabolic needs.

• Thyroid
• deficit at birth due to absent, underdeveloped, or ectopic thyroid gland

• Incidence
• 1:4000 births

• Detected
• by mandatory newborn screening

• If
• undetected or untreated profound mental retardation

an absent (Aplastic) underdevelped, or ectopic thyroid gland this group of congential defects is reffered to as Thyriod dysgenesis

can cause transient hypothyrodism

Transfer of maternal antibodies to the fetus.

• Skin
• mottling

• lLarge
• fontanel

• lLarge
• tongue

lHypotonia

• lSlow
• reflexes

• lDistended
• abdomen

Jaundice

• lUmbilical
• hernia

lLethargy

lConstipation

• lFeeding
• difficulties

• l“Hoarse
• cry”

• lExcessive
• sleeping

• Life-long
• replacement

• If
• suspected, do not delay treatment

• Teach
• parents symptoms of hypothyroid and hyperthyroid to help with medication
• management.

intellectual impairment

By testing for T4in newborn screening. at 2-6 days old.

Levothyroxine

a condition in which the thyroid galand produces an inadequate amount of thyroid hormone to meet the body's metabolic needs

• The
• child’s thyroid is underproductive

• Multiple
• causes but the most common is Hashimoto’s thyroiditis--an autoimmune response

• Autoantibodies
• cause decreased thyroid production and TSH levels rise—a goiter is common

Hashimoto's thyroiditis and is usually associated with a goiter it is a result of an autoimmune process.

Girls

2-3 years and are often reversible.

An enlarged thyroid gland that occure in response to increased TSH secretion autoimmune attack of the thyroid gland.

an autoimmune condition in which excessive thryoid hormones are produced by an enlarged thyroid gland.  it is most common cause of hyperthyroidism in children.

• Autoimmune
• condition causing excessive thyroid hormone production

• Incidence
• 1 in 5000

• 5x
• more likely in girls

• Peak
• age 11-15 yrs

• If
• undetected or untreated may result in cardiac failure and death

Hypothyroid 

Muscle atrophy

lDecreased pulse


lDelayed skeletal

lDelayed puberty

Hyperthyroid

• Muscle
• weakness

• Increased
• pulse

• High
• blood pressure

Tremor

• Increased
• appetite

lgoiter

Hypothyroidism

• lElevated
• TSH

• Low
• T 4

• lCirculating
• thyroid antibodies

Hyperthyroidism

• lDecreased
• TSH

• lElevated
• T 4

• lPositive
• autoantibodies

• lIncreased
• iodine uptake with scans

Hypothyroidism

• Rx
• replacement

Hyperthyroidism

Antithyroid drugs: propylthiouracil, methimazole

• Oral
• radioactive iodine

Thyroidectomy

Can cause liver toxicity.

• Antithyroid drug therapy
• radioactive iodine
• surgery

10 years old

Lugols solution (Potassium Iodine) give 10-14 dAYS prior to decrease glands vascularity. Calcium levels are monitored after surgery.

an inablitiy to concentrate urine.

Vasopressin also known as Antidiurtic hormone (ADH)

Vasopressin.

Diabetes Insipidus (high and dry)

• Cannot
• concentrate urine vasopressin—ADH deficit

• Underlying—commonly
• hypothalmic
• tumor

DI

• lPolydipsia,
• polyuria, nocturia,
• dehydration

• High
• serum Na

• SIADH
• (low and wet)

lExcessive release of ADH or vasopressin

Underlying—CNS conditions

• Syndrome
• of…SIADH

• lDecreased
• urination, increased urine sp. gravity, fluid retention, weight gain.

• lLow
• serum Na

• Fluid
• balance

lDDAVP

• lUrine
• specific gravity at 1.1010-1.020

• Correct
• cause

• Fluid
• restriction

• IV
• Na

• lSeizure
• precautions if sodium < 125

• Fluids
• synthetic vasopressin DDAVP

• sodium >150 meq/l 
• low urin specific gravity in the abscence of hyperglycemia