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3. Thyroid disorders in children-1.pptx

  1.  1. Goitre  Is an enlargement of the thyroid gland  May be congenital or acquired  Thyroid function may be normal –euthyroid  Underactive – hypothyroid  Overactive – hyperthyroidism  Enlargement is usually 2° to ↑sed pituitary secretion of TSH but may in certain cases, be due to an infiltrative process that may be either inflammatory or neoplastic
  2.  The commonest causes are due to transplacental transmission of factors that interfere with fetal thyroid fxn from the mother to the fetus  Maternal antithyroid drugs  Maternal iodine exposure  Maternal hyperthyroidism ( grave’s d’se)  Others– thyroid teratoma, endemic iodine def., thyroid hormone biosynthesis defect
  3.  Is simple euthyroid  Multinodular  Acute thyroidism  Grave’s dse  Antithyroid chemical exposure.  Iodine intoxication  Anti- thyroid drugs:
  4.  Hypothyroidism Is rare in children 1 in 4000 infants Is a serious threat to mental development Affects newborns and children
  5.  Occurs when there is insufficient secretion of thyroid hormone  Present from birth  Is the most common – 90% of all the infant hypothyroidism  Occurs when part of the fetal thyroid system fails to develop correctly . Sometimes the gland do not descent fully into the proper place.  Or thyroid underdevelopment
  6.  Athyrosis – absent gland Transient hypothyroidism 10% of cases is temporary Usually because the mother has been treated of grave’s disease or hyperthyroidism It can last from days to months
  7.  Children and adolescents are affected  Is an autoimmune thyroid disease e.g. Hashmoto’s disease  Is common at puberty and in girls than boys Diagnosis  HighTSH & low thyroxine 4 is hypothyroidism  PKU-- Phenylketonuria diagnostic of galactoseamia
  8.  X-ray of the bones– end of bones appear underdeveloped  Scan of the thyroid gland– will show malformed, improperly located or absent thyroid gland
  9.  Puffy face  Swollen tonque  Hoarse cry  Cold extremities  Mottled skin  Poor feeding  Thick coarse hair that goes low on the forehead, large fontanel  Prolonged jaundice, poor feeding, cons
  10.  Umbilical hernia  Lethergic – sleeps most of the time  Persistent consitpation, bloated or full to touch  Low body temperatures  Poor development  Permanent mental retardation  IQ is below 80  ADHD (attention deficit hyperactivity disorder) in older children
  11.  Oral thyroxine ( evothyroxine)  Dose 10-15 micro gram/ kg daily  Ensure normal growth & devpt Prognosis  Treatment is cheap, simple, and available. Most of them recover fully  Cretinism is an old term for the state of mental and physical retardation resulting from hypothyroidism due to iodine deficiency
  12.  Thyrotoxicosis refers to the clinical physiological and biochemical findings that result when tisssues are exposed to excess thyroid hormones  Causes  Excess thyroid stimulation  Grave’s disease,  neonatal thyrotoxicosis  Pituitary thyroid hormone resistance
  13.  Hyperactivity  Poor concentration, altered mood, insomnia  Heat intolerance  Weight loss  Diarrhoea  Menstrual irreqularities  Hyper pyrexia
  14.  Is a complex autoimmune disorders with both genetic and environmental factors contributing to susceptibility.  Clinical features Diffuse goitre Exophthalmos Ptosis Eye lid lag
  15.  Thyroid function test – HighT3 &T4 and low TSH  Thyroid antibody screen TREATMENT  Antithyroid drugs –carbimazole or propylthioracil –for 12 to 24 months  propranolol
  16.  The adrenal gland is composed of 2 endocrine tissues:  the medulla and  the cortex  Cortisol deficiency decreases negative feedback on the hypothalamus and pituitary, leading to increased secretion of ACTH
  17.  1° adrenal insufficiency may be caused by genetic conditions that are not always manifested in infancy and by acquired problems such as autoimmune conditions.
  18.  inborn errors of steroid biosynthesis,  sepsis,  adrenal hypoplasia congenita, and  adrenal hemorrhage.
  19.  Primary adrenal insufficiency leads to cortisol and often aldosterone deficiency.  Adrenal insufficiency presents with  Hypoglycemia  ketosis.  Ketosis is aggravated by anorexia, nausea, and vomiting,
  20.  Hyperkalemia,  hyponatremia, and  hypoglycemia are prominent presenting signs of adrenal insufficiency in infants.  Ketosis is not consistently present because infants generate ketones less well than do older children.  Hyperpigmentation usually takes weeks or months to develop, and  orthostatic hypotension is difficult to demonstrate in infants.
  21.  Cortisol deficiency -:  decreases cardiac output and vascular tone; catecholamines such as epinephrine have ↓ inotropic and pressor effects in the absence of cortisol.  manifested as orthostatic hypotension & shock
  22.  Aldosterone deficiency, →  hypovolemia.  Hypotension and decreased cardiac output  hyponatremia.  hyperkalemia
  23.  The onset is usually more gradual and is characterized by muscle weakness, malaise, anorexia, vomiting, weight loss, and orthostatic hypotension.  Hyperpigmentation is often but not necessarily present.  Hypoglycemia and ketosis are common, as is hyponatremia.  Hyperkalemia tends to occur later in the course of the disease in older children than in infants. Thus, can be easily confused with gastroenteritis or other acute infections.
  24.  Salt craving is seen in primary adrenal insufficiency with mineralocorticoid deficiency.  Fatigue, myalgias, fever, eosinophilia, lymphocytosis, hypercalcemia, and anemia may be noted with glucocorticoid deficiency
  25.  Hypoglycemia, ketosis, hyponatremia, and hyperkalemia .  An electrocardiogram is useful for quickly detecting hyperkalemia in critically ill Acidosis is frequently present, and the blood urea nitrogen level is elevated if the patient is dehydrated.
  26.  Iatrogenic secondary adrenal insufficiency (caused by chronic glucocorticoid administration) is best avoided by use of the smallest effective doses of systemic glucocorticoids for the shortest period of time.  Patients with anatomic lesions of the pituitary should be treated indefinitely with glucocorticoids. Mineralocorticoid replacement is not required.  In patients with panhypopituitarism treating cortisol deficiency may cause freewater excretion thus unmasking central diabetes insipidus.
  27. CAH is an autosomal recessive disorders of cortisol biosynthesis Cortisol deficiency increases secretion of corticotropin (ACTH), which in turn leads to adrenocortical hyperplasia and overproduction of intermediate metabolites.
  28. Depending on the enzymatic step that is deficient, there may be signs, symptoms, and laboratory findings of mineralocorticoid deficiency or excess; incomplete virilization or premature puberty in affected males; and virilization or sexual infantilism in affected females
  29.  is the result of abnormally high blood levels of cortisol or other glucocorticoids. This can be iatrogenic or the result of endogenous cortisol secretion, due either to an adrenal tumor or to hypersecretion of corticotropin (adrenocorticotropic hormone [ACTH]) by the pituitary (Cushing disease) or by a tumor
  30.  Bilateral adrenal hyperplasia Hypersecretion of corticotropin (Cushing disease) Ectopic secretion of corticotropin Exogenous corticotropin Adrenocortical nodular dysplasia Pigmented nodular adrenocortical disease (Carney complex) Tumor Carcinoma Adenoma
  31.  May be as early as 1 year  The face is rounded, with prominent cheeks and a flushed appearance (moon facies). Generalized obesity .  In children with adrenal tumors, signs of abnormal masculinization occur frequently;  there may be hirsutism on the face and trunk,  pubic hair,  acne,  deepening of the voice, and  enlargement of the clitoris in girls.
  32.  Growth is impaired, with length ˂ 3rd percentile,.  Hypertension is common & may → heart failure.  An ↑ susceptibility to infection →fatal sepsis.  In older children - Pubertal development may be delayed, or amenorrhea in girls past menarche.  Weakness, headache, and emotional lability may be prominent.  Hypertension and hyperglycemia usually occur;  hyperglycemia may progress to frank diabetes.  Osteoporosis is common, →pathologic fractures.
  33.  Cortisol levels in blood are normally elevated at 8 A.M. and decrease to less than 50% by midnight  Elevated nighttime salivary cortisol levels  Urinary excretion of free cortisol is increased.  A single-dose dexamethasone suppression test is often helpful; (a dose of 25–30 μg/kg (maximum of 2 mg) given at 11 P.M. results in a plasma cortisol level of less than 5 μg/dL at 8 A.M. the next morning in normal individuals but not in patients with Cushing syndrome.
  34.  A glucose tolerance test is often abnormal despite elevated levels of insulin.  Levels of serum electrolytes are usually normal, but potassium may be decreased, especially in patients with tumors that secrete ACTH ectopic
  35.  1. Obesity, Children with simple obesity are usually tall, whereas those with Cushing syndrome are short or have a decelerating growth rate.  2. generalized glucocorticoid resistance. Affected patients may be asymptomatic or exhibit hypertension, hypokalemia, and precocious pseudopuberty; these manifestations are caused by increased mineralocorticoid and adrenal androgen secretion in response to elevated ACTH levels.  3. Pituitary adenoma
  36.  Transsphenoidal pituitary microsurgery is the treatment of choice in pituitary Cushing disease in children.  success rate with follow-up of less than 10 yr is 60–80%.  Low postoperative serum or urinary cortisol concentrations predict long-term remission in the majority of cases.  Relapses are treated with re-operation or pituitary irradiation.
  37.  Cyproheptadine, a centrally acting serotonin antagonist that blocks ACTH release, has been used to treat Cushing disease in adults; remissions are usually not sustained after discontinuation of therapy. This agent is rarely used in children.  If a pituitary adenoma does not respond to treatment laparoscopically do Adrenalectomy
  38.  sepsis,  pancreatitis,  thrombosis,  poor wound healing, and sudden collapse, particularly in infants with Cushing syndrome.  increased bone density occur, but bone density remains abnormal and adult height is often compromised.
  39.  Pheochromocytomas, catecholamine- secreting tumors, arise from chromaffin cells.  90% arise from the adrenal medulla; however, tumors may develop anywhere along the abdominal sympathetic chain and are likely to be located near the aorta at the level of the inferior mesenteric artery or at its bifurcation.
  40.  Pheochromocytoma may be inherited as an autosomal dominant trait. In affected families, the ages of patients at the time of diagnosis have varied from the 1st to 5th decades of life;  more than half the patients have had multiple tumors.  Pheochromocytomas may also be associated with other syndromes such
  41.  Result from excessive secretion of epinephrine and norepinephrine.  All patients have hypertension at some time.  The hypertension in children is more often sustained rather than paroxysmal, in contrast to adults.  During attacks, the patient complains of headache, palpitations, abdominal pain, and dizziness; pallor, vomiting, and sweating also occur.
  42.  In severe cases, precordial pains radiate into the arms; pulmonary edema and cardiac and hepatic enlargement may develop.  Symptoms may be exacerbated by exercise.  The child has a good appetite but because of hypermetabolism does not gain weight, and severe cachexia may
  43.  Growth failure may be striking.  The blood pressure may range from 180 to 260 mm Hg systolic and from 120 to 210 mm Hg diastolic, and the heart may be enlarged.  Ophthalmoscopic examination may reveal papilledema, hemorrhages, exudate, and arterial constriction.
  44.  The urine may contain protein, a few casts, and occasionally glucose.  Gross hematuria suggests that the tumor is in the bladder wall. Polycythemia is occasionally observed.  The diagnosis is established by demonstration of elevated blood or urinary levels of catecholamines and their metabolites.
  45.  Various causes of hypertension in children must be considered, such as  renal or renovascular disease;  coarctation of the aorta;  hyperthyroidism;  Cushing syndrome;  Neuroblastoma,  ganglioneuroblastoma, and ganglioneuroma frequently produce catecholamines.  Secreting neurogenic tumors
  46.  Removal of these tumors results in cure, but the operation is very high risk.  Careful preoperative, intraoperative, and postoperative management is essential. Preoperative α- and β-adrenergic blockade and fluid loading are required.  Because these tumors are often multiple in children, a thorough transabdominal exploration of all the usual sites offers the best opportunity to find them all.
  47.  Appropriate choice of anesthesia and expansion of blood volume with appropriate fluids during surgery are critical to avoid a precipitous drop in blood pressure during operation or within 48 hr postoperatively.  Manipulation and excision of these tumors result in marked increases in catecholamine secretion that increase blood pressure and heart rate. Surveillance must continue postoperatively.