Endocrinology Flashcards
1
Q
diabetes mellitus
A
- Fasting blood sugar over 126 mg/dL
- or
- Non-fasting blood sugar over 200 (Sporadic hyperglycemia, usually during illness or after steroids, is common in children)
- HbA1C > 6.5% is suggestive, but needs to be confirmed with hyperglycemia.
- Positive result on glucose tolerance test- Rarely done in pediatrics.
2
Q
type 1 DM
A
- Insulin deficiency
- Low C-peptide
- Autoimmune destruction of pancreatic β cells
- Most common endocrine problem in children
- 1 in 300-500 people under 18 years of age
- Postprandial hyperglycemia is first finding
- Prone to ketosis with more complete insulin deficiency
- Higher rates in Caucasian populations
- Associated with other autoimmune illness (ex. thyroid disorders, Celiac)
- Clinical presentation:
- Polyuria
- may manifest as enuresis
- Polydipsia
- Polyphagia
- often with paradoxical weight loss
- Dehydration/ketosis
- abdominal pain
- vomiting
- worsening mental status/fatigue
- breath & sweat ketosis
- Polyuria
- Diabetic Ketoacidosis (DKA) – most kids who have type 1 present in DKA
- Metabolic Acidosis: arterial pH < 7.3, bicarbonate <15 mEq/L
- Ketosis: Ketones in blood (>3mmol/L) or urine (moderate-large)
- Hyperglycemia >200 mg/dL
- Often the presenting diagnosis for T1DM.
- Leading cause of morbidity and mortality in children with T1DM
- Laboratory Findings
- Elevated glucose level
- Electrolytes:
- Anion Gap
- Hyponatremia (Can be exaggerated by high glucose)
- Potassium will be falsely normal/high (Total body low)
- Renal dysfunction if long standing
- Urinalysis – very cheap and easy test! One of the most useful tests!
- glycosuria
- ketones
- You should NEVER see ketones in urine in a normal kid
- ketones
- low pH
- Auto-antibodies and insulin-like growth factor (not needed in the initial period)
- “Honeymoon” period often follows original diagnosis where the pancreas is still able to produce a significant amount of insulin.
- First presentation of DKA is often set off by acute illness. The stress of illness causes the body to require more insulin than is needed for it’s basal function.
- Long term treatment goals:
- glucose control
- insulin regimen
- diet
- Avoid complications in chronic management
- renal failure
- visual impairment
- cardiovascular disease
- iatrogenic hypoglycemia
- ketosis during dehydrating circumstances
- glucose control
3
Q
diabetic ketoacidosis
A
- Treatment of DKA
- IV Fluid Rehydration
- Often helps reduce acidosis and glucose levels
- Must be done gently. Rapid or excessive IV fluid repletion can cause cerebral edema and be fatal.
- Careful electrolyte restoration.
- Monitor electrolytes carefully and replete.
- Restoration of anabolic state
- Insulin- restores euglycemia and halts ketone production
- You would never use hypertonic saline because the kid is actually isotonic, it just looks like they aren’t
- IV Fluid Rehydration
4
Q
type II DM
A
- Insulin Resistance
- hyperinsulinemia
- reduced sensitivity to insulin
- Gradual onset of symptoms
- DKA presentation uncommon due to presence of insulin
- Growing more common in younger ages
- correlation with worsening of American obesity epidemic
- Risk factors for type II diabetes:
- Family history
- Ethnicity (African American and Latino populations at higher risk)
- Weight
- Polycystic ovarian syndrome
- Diagnosis
- random glucose concentration > 200mg/dl
- fasting plasma glucose > 126 mg/dl
- glucose tolerance testing
- 2-hour plasma glucose > 200 mg/dl
- glycated hemoglobin (HgbA1C) is used as a screening test (and is used for diagnosis in adults)
- Co-moribidities
- dyslipidemia
- hypertension
- obesity
- Treatment: Glucose control and lifestyle modification
- lifestyle
- diet
- exercise
- metformin
- reduces hepatic glucose production
- increases sensitivity to insulin
- reduces intestinal glucose absorption
5
Q
neonatal hypoglycemia
A
- Very common in first 3 days of life, as metabolic needs outstrip energy stores
- In neonates, serum level <40 mg/dL is abnormal (we think) however some lower values in the 1st 4 hours of life may be normal.
- If symptomatic with low glucose this is ALWAYS abnormal
- Jittery, lethargic, seizures
-
Differential diagnosis
- Hyperinsulinism (infant of diabetic mother)
- Causative illness (shock, heart failure, liver dysfunction)
- Intoxication (alcohol), drug effects
- Inadequate substrate (SGA, poor feeding)
- Counter-regulatory hormone deficiency
- metabolic disorder inhibiting normal response
- gluconeogenesis
- glycogenolysis
- fatty acid oxidation
- organic acid metabolic disorder
- galactosemia
- Management
- Give glucose:
- Feed the infant for mild to moderate hypoglycemia
- Give IV glucose for severe, persistent or symptomatic illness
- Normal hypoglycemia should resolve in 24-48 hours, if it persists additional workup should be considered:
- “Critical Sample” – Send blood and urine when hypoglycemic to assess the insulin and metabolic response
- Give glucose:
6
Q
adrenal gland
A
- Endocrine organ that produces hormones important for salt homeostasis, stress response, and sexual characteristics.
7
Q
congenital adrenal hyperplasia
A
- Family of disorders that is caused by inactivity of key enzymes involved in adrenal hormone production.
- These disorders result in decreased production of cortisol. As a result there is an increased release of CRH and ACTH that leads to adrenal hyperplasia.
- The 3 most common are:
- 21-hydroxylase deficiency
- 11-beta hydroxylase deficiency
- 17-alpha hydroxylase deficiency
8
Q
21-hydroxylase deficiency
A
- By far the most common form of CAH.
- Presents with virilized genitalia in females. Males may not have a detectable phenotype.
- Internal genitalia will be normal. Which is why ultrasound is useful to demonstrate presence of uterus and ovaries in virilized females.
- Tested for on the state genetic screen.
- Babies generally present with vomiting, lethargy and in salt-wasting crisis.
- Labs will show low sodium levels from salt wasting due to lack of aldosterone.
- Treatment: glucocorticoid, mineralocorticoid replacement and possible surgical correction of external genitalia.
9
Q
Addison disease
A
- Primary adrenal insuficiency
- Autoimmune destruction of adrenal cortex
- glucocorticoid and mineralocorticoid deficiencies
- Episodes of shock during severe illness
- Treated with oral glucocorticoids and mineralocorticoids
10
Q
Adrenal crisis
A
- An emergency to be aware of in any patient who has adrenal insufficiency.
- Can present with hypotension, lethargy, and shock.
- In times of stress or illness the body has an increased cortisol need that people with AI cannot compensate for.
- People with AI need stress dose steroids during these times. Anyone with known AI should have a “sick plan”.
11
Q
panhypopituitarism
A
- The pituitary gland produces 7 hormones that are integral in the function of the body.
- Anterior: TSH, ACTH, FSH, LH, GH, Prolactin
- Posterior: ADH, Oxytocin
- Loss of the pituitary gland can occur due to trauma or shock that compromises the blood supply.
- in children, special attention paid to growth hormone replacement
- thyroxine replacement
- glucocorticoid replacement
- diabetes insipidus (free water loss, hypernatremia) is treated with desmopressin
- attention to sex hormone replacement depending on age & gender
12
Q
thyroid organogenesis
A
- thyroid develops from 3rd and 4th pharyngeal pouches starting in the 4th week of gestation
- by the 7th week the thyroid has migrated and the thyroglossal duct degenerates
13
Q
congenital hypothyroidism
A
- during first two weeks of life
- large fontanelles
- hypothermia
- poor feeding
- prolonged jaundice
- beyond 1 month of age
- darkened, mottled skin
- labored breathing
- diminished stool frequency
- lethargy
- after 3 months
- umbilical hernia
- infrequent, hard stools
- dry skin with carotenemia
- macroglossia
- generalized swelling (myxedema)
- 90% due to thyroid dysgenesis: athyreosis, ectopia, or hypoplasia
- Generally diagnosed via Newborn screening in the US and usually treated before symptomatic.
- Symptomatic infants adopted from other countries may present for care.
- False positive newborn screens are seen particularly in premature infants.
14
Q
acquired hypothyroidism
A
- 6 months to 3 years:
- deceleration of linear growth
- umbilical hernia
- dry skin with carotenemia
- macroglossia, hoarse cry
- During childhood:
- Goiter
- delayed eruption of teeth, shedding of primary teeth
- muscle weakness, pseudohypertrophy
- infrequent, hard stools
- precocious sexual development: breast development or enlarged testes without sexual hair
- generalized swelling (myxedema) – may cause weight gain
15
Q
causes of acquired hypothyroidism
A
- Hashimoto’s (autoimmune) thyroiditis
- AKA lymphocytic thyroiditis
- Most common cause
- drug-induced hypothyroidism via medications
- in breastmilk
- lithium, propylthiouracil (PTU), methimazole
- endemic goiter (iodine deficiency)
- irradiation
- excision
