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23 Cards in this Set
- Front
- Back
Where is the pituitary gland located? What is it attached to? |
- Located at the base of the brain in the bony cavity of the sphenoid bone (sella turcica) - It is the size of a pea (500 mg) and attached to the overlying hypothalamus by the hypophyseal stalk (pituitary stalk) |
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How much of the pituitary is the anterior pituitary? What does it secrete? |
- The anterior pituitary is 80% of the pituitary gland - It secretes 6 hormones: * Growth Hormone * Adrenocorticotrophic hormone (ACTH) * TSH * FSH * LH * Prolactin |
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What stimulates or inhibits the release of anterior pituitary hormones to act on target organs? |
- The hypothalamic–pituitary–adrenal axis (HPA axis) - Hormones from the hypothalamus - Closed loop negative feedback |
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What are causes of hyposecretion in the pituitary? |
- Pan hypopituitarism is the most common response (generalized pituitary dysfunction) instead of one specific hormone reduced -Causes: * Tumor * Postpartum shock (Sheehan's syndrome) * Irradiation * Trauma * Hypophysectomy |
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What is the treatment for a pituitary tumor? |
Transsphenoidal resection |
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What medications may a pt. need preop when they are awaiting transsphenoidal resection? |
- Thyroid replacement - Corticosteroid coverage |
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If the pt. develops diabetes insipidus intraoperatively, what medication will you use to treat this? |
- Vasopressin |
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Will you deep extubate a pt. having a transphenoidal resection? |
- No, the pt. needs to be awake so a neurological exam can be performed
- Prepare the pt. preoperatively for this as well as explain that they will have nasal packing and this will be uncomfortable. They will have to breathe through their mouth |
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What is dwarfism a result of ? Are these individuals at risk for a difficult airway? What is the treatment for dwarfism? |
- Hyposecretion of growth hormone (GH) - Yes these individuals are often at risk for a difficult airway - These individuals receive human growth hormone |
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What causes hypersecretion of the anterior pituitary? |
- Pituitary adenomas that may over-secrete: * Prolactin * ACTH * GH |
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What are treatments for prolactin-secreting tumors? |
- Bromocriptine (dopamine agonist) - Microsurgical removal |
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What is the difference between gigantism and acromegaly? |
- Acromegaly: Produced by sustained hypersecretion of GH after adolescence.
- Gigantism: Hypersecretion of GH before puberty (before closure of growth plates). |
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What is the treatment for over-secretion of GH? |
- Microsurgical removal of tumor - Octreotide - Bromocriptine - Gland irradiation |
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What are airway considerations for a patient with gigantism or acromegaly? |
- Facial deformities, large nose hinder masking - Macroglossia, enlarged thyroid, hypertrophy of epiglottis, overgrowth of soft tissue in upper airway→difficult DL
- Subglottic narrowing, vocal cord enlargement→ use of smaller ETT.
- Turbinate enlargement precludes nasal intubations. |
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What are intraop considerations for oversecretion of GH? |
- Thyroid replacement - Steroid coverage - Close monitoring of glucose and electrolytes - Awake extubation- predisposed to airway obstruction |
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Which hormones does the posterior pituitary secrete? How are these hormones secreted? |
- Antidiuretic hormone (Vasopressin or ADH) - Oxytocin - The posterior pituitary is composed of terminal neuron endings that originate in the hypothalamus - ADH and oxytocin are synthesized in the hypothalamus and stored in the posterior pituitary |
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True or False. Nephrogenic DI can have multiple causes such as: x-linked inherited trait, hypercalcemia, hypokalemia, medication-induced nephrotoxicity, Ethanol, Phenytoin, Chlorpromazine, or Lithium |
True. Nephrogenic DI is the inability of renal collecting duct receptors to respond to ADH |
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True or False. Neurogenic DI is hypersecretion of ADH and is caused by headtrauma, neurosurgical procedures, infiltrating pituitary lesions, brain tumors. |
False. Neurogenic DI is hyposecretion of ADH |
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True or False. There are many factors related to surgery that increase ADH release. |
True. ADH is stimulated by: * Pain * Stress * Nausea * Decreased BP * Decreased blood volume * Various medications (morphine, nicotine) * Angiotensin II * Positive pressure ventilation * Increased serum osmolarity * Increased plasma sodium ion concentration |
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What is the treatment for DI? |
- Vasopressin (Arginine vasopressin/ AVP) at 0.5-15 U/hr - DDAVP(Arginine Desmopressin): 0.3 µg/kg IV over 15-30 min or2-4 µg/ day in two divided doses. - Both vasopressin and DDAVP cause:Splanchnic vasoconstriction. Increased smooth muscle contractility. |
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True or false. Besides low urine output, surgical patients with SIADH exhibit delayed awakening from anesthesia |
True |
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What are treatments for SIADH? |
- Fluid restriction - Slow IV infusion of 3% hypertonic solution - IV Lasix - Demeclocycline (tetracycline antibiotic) |
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How many types of MEN syndrome are there? |
There are 3 types: - MEN 1 * Wermer's syndrome: Consists of pancreatic, pituitary, and parathyroid tumors - MEN IIa * Sipple’s syndrome: Medullary thyroid cancer, parathyroid adenoma, pheochromocytoma - MEN IIb * Mucosal neuroma syndrome: Medullary thyroid tumor, pheochromocytoma, neuromas of the oral mucosa, marfanoid habitus |