THYROID Zelne Zamora DNP RN THYROID HORMONE Hormones

THYROID Zelne Zamora, DNP, RN

THYROID HORMONE Hormones Thyroxine (T 4) Triiodothyronine (T 3) Calcitonin or Thyrocalcitonin Regulated by negative feedback mechanism

Thyroid 2 types of cells Parafollicular cells – calcitonin Follicular cells – composed of iodine atoms Thyroxine (T 4) Triiodothyronine (T 3)

THYROID HORMONE Amino acids containing iodine molecules T 4 has four iodine atoms, T 3 has three Stored and bound to proteins until needed then released into bloodstream T 4 T 3

THYROXINE HORMONE T 4 Relatively weak hormone Regulates body metabolism Thermal regulation Regulation of physical and mental development

TRIIODOTHYRONINE T 3 Five times more potent then T 4 More rapid metabolic action Present in much smaller quantities

THYROCALCITONIN Secreted in response to high plasma levels of calcium Lowers calcium by increasing bone deposition Not as important due to parathyroid

NEGATIVE FEEDBACK Hypothalamus Thyrotropin releasing hormone (TRH) Anterior pituitary Thyroid stimulating hormone (TSH) Thyroid gland Thyroid hormones (T 3, T 4)

NEGATIVE FEEDBACK

NORMAL SECRETION Sufficient protein and iodine Thyroid functioning properly Anterior pituitary functioning properly Thyroid releasing hormone (TRH) from hypothalamus

HYPERTHYROIDISM Overactivity of the thyroid gland Increase of thyroid hormone

ETIOLOGY Primary Problem with the thyroid itself Autoimmune: Graves’ disease Toxic multinodular goiter Single toxic nodule: Plummer’s disease

ETIOLOGY Secondary Pituitary tumor Hyperfuncion of pituitary gland Results in increased TSH Negative feedback mechanism dysfunction

CLINICAL MANIFESTATIONS ↑ basal metabolic rate (BMR) ↑ heat production ↑ appetite ↑ bodily processes Warm and soft skin

CLINICAL MANIFESTATIONS Agitated Irritable Nervous Insomnia Hyperactivity Muscle weakness

CLINICAL MANIFESTATIONS Goiter Enlargement of gland Dermopathy Thickening and discoloration of skin Subcutaneous tissue

CLINICAL MANIFESTATIONS Exophthalmos Abnormal protrusion of eyes Interventions HOB elevated Low Na diet Tape eyes at night Sunglasses Diuretics

DIAGNOSTIC FINDINGS Increase T 3 & T 4 TSH Primary: decrease Secondary: increase ↑ radioactive iodine uptake test (RAIU) ↑ serum thyroid antibodies

DIAGNOSTIC FINDINGS Radioactive Iodine Uptake Test (RAIU) Radioactive Iodine Tracer Detects radiation given off by tracer Precautions

DIAGNOSTIC FINDINGS Fine-needle aspiration biopsy Evaluate thyroid masses Detect malignancy

NURSING DIAGNOSIS Discomfort r/t heat intolerance Activity intolerance r/t muscle fatigue, inability to rest Weight loss r/t intake < metabolic needs

RADIOACTIVE IODINE THERAPY Radioactive Iodine 131 I concentrated in thyroid gland Destroy overactive thyroid cells Hyperthyroid to hypothyroid state Thyroid storm

ANTITHYROID MEDICATIONS Propylthiouracil (PTU), Methimazole (Tapazole) Blocks hormone synthesis or release Prevents iodine and tyrosine combining Decreases

ANTITHYROID MEDICATIONS Side Effects Mild GI irritation Rash Agranulocytosis

SURGICAL MANAGEMENT Subtotal thyroidectomy 75 -80% of thyroid tissue removed Total Thyroidectomy cancer

PREOPERATIVE INTERVENTIONS Antithyroid medications PTU, Methimazole Iodine Lugol’s solution or Saturated Solution of K+ Iodide

PREOPERATIVE INTERVENTIONS Beta blocker Propanolol Control HR and BP ↓ Cardiac Workload Optimum nutrition Rest

POSTOPERATIVE INTERVENTIONS Airway Laryngeal edema, nerve damage, tracheal compression HOB elevated Tracheostomy tray at bedside O 2 and suction Assess voice quality

POSTOPERATIVE INTERVENTIONS Hemorrhage Vital signs Check behind neck Support head to decrease tension on suture line

POSTOPERATIVE INTERVENTIONS Hypocalcemia Injury or removal of parathyroid Numbness, tingling Muscle twitching Cardiac arrhythmias Chvostek and Trousseau sign

POSTOPERATIVE INTERVENTIONS Hypocalcemia 1 -7 days post-op Notify MD immediately Calcium gluconate Seizure precautions O 2 and suction Tracheostomy tray at bedside

COMPLICATIONS Cardiac Tachycardia Atrial fibrillation CHF Thyroid storm

THYROID STORM Acute episode of thyroid overactivity Commonly occurs in Grave’s disease Signs and symptoms are amplified

PRECIPITATING FACTORS Surgery Infection or sepsis Trauma MI or PE Radioactive iodine Inadequate prep for thyroid surgery

CLINICAL MANIFESTATIONS High fever Severe tachycardia Cardiac dysrhythmias Severe HTN Nausea, vomiting, diarrhea Dehydration

CLINICAL MANIFESTATIONS Extreme irritability Agitation Delirium Confusion Coma

INTERVENTIONS Identify cause and treat Antithyroid drugs K+ iodide Beta blockers Propanolol

INTERVENTIONS Digoxin Tylenol (not ASA) Cooling blankets IV fluid Oxygen

HYPOTHYROIDISM Under activity of the thyroid Decrease thyroid hormone

ETIOLOGY Primary Autoimmune: Hashimoto’s thyroiditis Nodules Secondary Pituitary tumors Pituitary surgery Tertiary Hypothalamic disorders Iatrogenic Radioactive Iodine ablation Thyroidectomy Amiodarone Lithium Interferon

CLINICAL MANIFESTATIONS ↓ BMR ↓ heat production ↓ appetite ↑ weight Generalized nonpitting edema Goiter development

CLINICAL MANIFESTATIONS Generalized nonpitting edema Goiter development Pallor, dry, cold skin Thick, brittle nails

CLINICAL MANIFESTATIONS Brittle hair Hoarseness Slowed movements Muscle cramps Delayed recovery phase of DTR

CLINICAL MANIFESTATIONS Impaired concentration Lethargic Mood changes Depression Changes in personal relationships

DIAGNOSTIC FINDINGS Decrease T 3 & T 4 TSH Primary: increase Secondary: decrease Anti-thyroid peroxidase antibodies: Hashimoto thyroiditis

NURSING DIAGNOSIS Depression r/t fatigue or weight gain Discomfort r/t cold intolerance Alteration in selfimage r/t change in physical appearance Constipation r/t decrease peristalsis secondary to decrease BMR Activity intolerance r/t fatigue and muscle weakness

INTERVENTIONS Thyroid hormone replacement Levothyroxine (Synthroid) Taken on an empty stomach Caution when substituting with generics

INTERVENTIONS Levothyroxine (Synthroid) Side effects similar to s/s hyperthyroidism elderly population or cardiac disease: angina, palpitations

INTERVENTIONS Keep patient warm Prevent constipation Pace activities Avoid sedatives, narcotics, anesthetics

COMPLICATIONS Coronary artery disease Hypertension Myocardial Infarction Congestive Heart

MYXEDEMA COMA Extreme manifestation of hypothyroidism Systemic decompensation Women > men Cold weather

PRECIPITATING FACTORS Hypothermia Stroke Heart failure Infection Metabolic disturbances Trauma GI bleeding Acidosis Hypoglycemia Hypercalcemia

CLINICAL MANIFESTATIONS Mental status changes Hypothermia < 94°F Hypoventilation Hypoxemia Hypercapnia

CLINICAL MANIFESTATIONS Bradycardia Hypotension Decreased peristalsis

INTERVENTIONS Intravenous Levothyroxine Supportive care for symptoms Monitor for heart failure Treat cause

CRETINISM Deficiency of thyroid hormone during fetal life Defective physical development Mental retardation Some effects reversed with immediate treatment Treat with daily doses of T 4

GOITER Hyperthyroidism: Graves’ disease Hypothyroidism: Hashimoto’s thyroiditis

GOITER Euthyroid: iodine deficiency Compensated hypothyroidism More common in underdeveloped countries “Goiter belt” in Northwest, Midwest & Great Lakes Region

TREATMENT Supplementary iodine SSKI Thyroid replacement hormone Subtotal thyroidectomy

QUESTIONS