Endocrine (Exam IV) Flashcards
1
Q
What is required for a normal glucose level?
A
A balance between glucose usage, endogenous production, and dietary intake.
2
Q
What is the primary source of glucose production?
A
The liver via glycogenolysis and gluconeogenesis.
3
Q
What percentage of glucose released by the liver is freely metabolized by tissues?
A
75%.
4
Q
What happens 2-4 hours after eating when glucose usage exceeds availability?
A
Endogenous production occurs to maintain a normal plasma glucose level and insulin production diminishes.
5
Q
How does glucagon play a primary role in regulating glucose level?
A
*Stimulating glycogenolysis
*Simulating gluconeogenesis
*Inhibiting glycolysis
6
Q
Which hormones help regulate blood glucose levels?
A
- Glucagon
- Epinephrine
- Growth hormone
- Cortisol
7
Q
What is diabetes mellitus?
A
The most common endocrine disease affecting 1 in 10 adults, resulting from inadequate supply of insulin and/or tissue resistance to insulin.
8
Q
What are the two main types of Type 1 diabetes?
A
- Type 1a DM: Autoimmune destruction of pancreatic β cells
- Type 1b DM: Non-immune absolute insulin deficiency
9
Q
Type 2 DM is also ___________, and results from defects in _____________ and _________________
A
Type 2 DM is also non-immune, and results from defects in insulin receptors and signaling pathways
10
Q
What percentage of all DM cases does Type 1 diabetes account for?
A
5-10%.
11
Q
What is the typical age of diagnosis for Type 1 diabetes?
A
Before age 40.
12
Q
What are some symptoms of hyperglycemia?
A
- Fatigue
- Weight loss
- Polyuria
- Polydipsia
- Blurry vision
- Hypovolemia
- Ketoacidosis
13
Q
What percentage of diabetes cases does Type 2 diabetes account for?
A
> 90%.
14
Q
What are the three main abnormalities seen in Type 2 diabetes?
A
- Impaired insulin secretion
- Increased hepatic glucose release
- Insufficient glucose uptake in peripheral tissues
15
Q
What factors contribute to insulin resistance in Type 2 diabetes?
A
- Abnormal insulin molecules
- Circulating insulin antagonists
- Insulin receptor defects
- Obesity and sedentary lifestyle (acquired)
16
Q
What are the main diagnostic tests for diabetes?
A
- Fasting blood glucose
- HbA1c
17
Q
Levels of A1c and what they indicate
A
Normal: 5.7%
Prediabetes: 5.7-6.4%
Diabetes: >6.5
18
Q
What are the preferred PO antidiabetic drugs?
A
*Metformin-preferred initial drug treatment
*Sulfonylureas
19
Q
How does metformin help with DM?
A
Class: A biguanide
Enhances glucose transport into tissues
↓TGL & LDL levels
20
Q
Sulfonylurea MOA
A
MOA: Stimulate insulin secretion
Enhances glucose transport into tissues
21
Q
What are the side effects of sulfonylureas?
A
- Hypoglycemia
- Weight gain
- Cardiac effects
22
Q
What is the most dangerous complication of long term insulins?
A
Hypoglycemia.
23
Q
Rapid acting insulins
A
Lispro
Aspart
24
Q
Short Acting insulin
A
Regular
25
Basal/intermediate acting insulin
NPH
Lente
26
Long Acting Insulin
Ultralente, Glargine
27
Hypoglycemia Unawarenss
Pt becomes desensitized to hypoglycemia and doesn’t show autonomic sx. Can happen after repetitive hypoglycemia episodes
28
What can hypoglycemia be exacerbated by?
ETOH
metformin
sulfonylureas
ACE-I’s
MAOI’s
Non-selective BB’s
29
What is diabetic ketoacidosis (DKA)?
A complication of decompensated diabetes, often seen in Type 1 triggered by infection/illness, characterized by high glucose levels and ketoacid overproduction.
30
What is the treatment for diabetic ketoacidosis?
* IV volume replacement
* Regular insulin
* Correct acidosis (bicarb)
* Electrolyte supplementation
31
Correction of glucose w/o simultaneous correction of sodium may result in ___________
cerebral edema
32
Regular Insulin Dose for DKA
Loading dose 0.1u/kg + low dose infusion @ 0.1u/kg/hr
33
Main distinguishing factor between HHS and DKA
presence of ketones
34
What characterizes hyperglycemic hyperosmolar syndrome?
Severe hyperglycemia, hyperosmolarity, and dehydration.
35
What are some complications of diabetes?
* Microvascualr
*Nephropathy
* Peripheral neuropathy
* Retinopathy
* Autonomic neuropathy
36
When can kidneys no longer clear K+?
GFR<15-20
37
What percentage of Type 1 diabetes patients develop end-stage renal disease (ESRD)?
30-40%.
38
What is the primary cause of hypothyroidism?
Ablation of the gland by radioactive iodine or surgery.
39
What is myxedema coma?
A rare, severe form of hypothyroidism characterized by delirium, hypoventilation, and hypothermia.
40
What are the symptoms of hyperthyroidism?
* Sweating
* Heat intolerance
* Fatigue
* Insomnia
* Osteoporosis
* Weight loss
41
What is the leading cause of hyperthyroidism?
Graves disease.
42
What is the treatment for Graves disease?
* Antithyroid drugs (methimazole or PTU)
* Iodine therapy for temporary effect
* β-blockers for symptom relief
* Surgery if medical treatment fails
43
What is the normal TSH level?
0.4-5.0 milliunits/L.
44
What is the T4/T3 ratio in thyroid hormones?
10:1.
45
What triggers thyroid storm?
Stress, trauma, infection, medical illness, or surgery.
46
What is the treatment for myxedema coma?
* IV L-thyroxine or L-triiodothyronine
* IV hydration with glucose solutions
* Electrolyte correction
* Supportive care
47
What is the Whipple triad used for in diagnosing insulinoma?
* Hypoglycemia with fasting
* Blood glucose <50 with symptoms
* Symptom relief with glucose
48
What is the most common cause of primary hypothyroidism?
Ablation of the thyroid gland.
49
What are the symptoms of hypothyroidism?
* Cold intolerance
* Weight gain
* Nonpitting edema
* Slow GI function
50
What is the mortality rate associated with a medical emergency involving cold and CNS depressants?
> 50%
51
What is the treatment for a medical emergency involving cold and CNS depressants?
IV L-thyroxine or L-triiodothyronine, IV hydration w/glucose solutions, temperature regulation, electrolyte correction, and supportive care
52
What is frequently required in cases of severe medical emergencies related to cold and CNS depressants?
Mechanical ventilation
53
What causes a goiter?
Lack of iodine, ingestion of goitrogen, or a hormonal defect
54
In most cases, how is a goiter associated with thyroid function?
Compensated euthyroid state
55
When is surgery indicated for a goiter?
If medical treatment is ineffective, and goiter compromises airway or is cosmetically unacceptable
56
What imaging technique must be examined to assess the extent of a thyroid tumor?
CT scan
57
What does dyspnea in upright or supine position predict during general anesthesia?
Airway obstruction
58
What do flow-volume loops indicate regarding obstruction?
Location and degree of obstruction
59
What can an echocardiogram assess in thyroid surgery complications?
Degree of cardiac compression
60
What is a potential complication of thyroid surgery related to the recurrent laryngeal nerve?
Injury may be unilateral or bilateral, temporary or permanent
61
What occurs if there is unilateral recurrent laryngeal nerve injury?
Vocal hoarseness without obstruction, usually resolves in 3-6 months
62
What may bilateral recurrent laryngeal nerve involvement cause?
Airway obstruction and may warrant tracheostomy
63
What can result from inadvertent parathyroid damage during thyroid surgery?
Hypoparathyroidism
64
When do symptoms of hypocalcemia occur postoperatively?
Within 48 hours
65
What complication can a hematoma lead to after thyroid surgery?
Tracheal compression
66
What should be kept at the bedside during the immediate postoperative period following thyroid surgery?
A tracheostomy set
67
What does each adrenal gland consist of?
A cortex and a medulla
68
What hormones are synthesized by the adrenal cortex?
* Glucocorticoids * Mineralocorticoids (aldosterone) * Androgens
69
What hormone does the hypothalamus send to the anterior pituitary?
Corticotropin-releasing hormone (CRH)
70
What does ACTH stimulate in the adrenal cortex?
Production of cortisol
71
What is the role of cortisol in the body?
Helps convert norepinephrine to epinephrine and induces hyperglycemia
72
What effect do cortisol and aldosterone have on sodium and potassium?
Caus sodium retention and potassium excretion
73
What is a pheochromocytoma?
Catecholamine-secreting tumor originating from chromaffin cells
74
What can excess catecholamines from a pheochromocytoma lead to?
Malignant hypertension, cerebrovascular accident (CVA), and myocardial infarction (MI)
75
What is the most common location for pheochromocytomas?
Adrenal medulla (80%)
76
What is the NE:EPI ratio typically secreted by most pheochromocytomas?
85:15
77
What symptoms can occur during a pheochromocytoma attack?
* Headache * Pallor * Sweating * Palpitations * Hypertension * Orthostatic hypotension
78
What diagnostic tests are used for pheochromocytoma?
* 24-hour urine collection for metanephrines and catecholamines * CT * MRI
79
What is the preoperative treatment for pheochromocytoma?
Alpha blocker to lower blood pressure and decrease intravascular volume
80
What is the most frequently used preoperative alpha blocker?
Phenoxybenzamine
81
Why should nonselective beta-blockers not be given before alpha blockers?
Blocking vasodilatory β2 receptors results in unopposed α agonism, leading to vasoconstriction and hypertensive crises
82
What are the two forms of hypercortisolism (Cushing Syndrome)?
* ACTH dependent * ACTH independent
83
What characterizes ACTH-dependent Cushing's?
High plasma ACTH stimulates adrenal cortex to produce excess cortisol
84
What characterizes ACTH-independent Cushing's?
Excessive cortisol production by abnormal adrenocortical tissue that is not regulated by CRH and ACTH
85
What symptoms are associated with hypercortisolism (Cushing Syndrome)?
* Sudden weight gain * Central obesity * Moon face * Ecchymoses * Hypertension * Glucose intolerance * Muscle wasting * Depression * Insomnia
86
What diagnostic test is used for Cushing's syndrome?
24-hour urine cortisol
87
What is the treatment of choice for resectable Cushing's disease?
Transsphenoidal microadenomectomy
88
What is primary hyperaldosteronism characterized by?
Excess secretion of aldosterone due to a tumor (aldosteronoma)
89
What is a hallmark symptom of hyperaldosteronism (Conn Syndrome)?
Spontaneous hypertension with hypokalemia
90
What is the treatment for primary hyperaldosteronism?
Aldosterone antagonist (Spironolactone), potassium replacement, antihypertensives, diuretics, tumor removal, possible adrenalectomy
91
What is the hallmark of hypoaldosteronism?
Hyperkalemia in the absence of renal insufficiency
92
What are the two types of adrenal insufficiency?
* Primary (Addison's disease) * Secondary
93
What causes primary adrenal insufficiency (Addison's disease)?
Autoimmune adrenal gland suppression
94
What is the diagnostic criterion for adrenal insufficiency?
Baseline cortisol < 20 μg/dL and remains < 20 μg/dL after ACTH stimulation
95
What do the parathyroid glands produce?
Parathyroid hormone (PTH)
96
What stimulates the release of PTH?
Hypocalcemia
97
What is primary hyperparathyroidism primarily caused by?
Benign parathyroid adenoma (90%)
98
What are the symptoms of hyperparathyroidism?
* Lethargy * Weakness * Nausea/vomiting * Polyuria * Renal stones * Peptic ulcer disease * Cardiac disturbances
99
What is the treatment for primary hyperparathyroidism?
Surgical removal of abnormal portions of the gland
100
What characterizes secondary hyperparathyroidism?
Compensatory response of parathyroid glands to counteract hypocalcemia
101
What is the most common cause of hypoparathyroidism?
Iatrogenic due to inadvertent removal of parathyroid glands
102
What are the symptoms of chronic hypocalcemia?
* Fatigue * Cramps * Prolonged QT interval * Cataracts * Subcutaneous calcifications * Neurologic deficits
103
What does the pituitary gland consist of?
Anterior pituitary and posterior pituitary
104
What hormones does the anterior pituitary secrete?
* Growth hormone (GH) * Adrenocorticotropic hormone (ACTH) * Thyroid-stimulating hormone (TSH) * Follicle-stimulating hormone (FSH) * Luteinizing hormone (LH) * Prolactin
105
What is acromegaly characterized by?
Excessive growth hormone
106
What is the most common cause of acromegaly?
Anterior pituitary adenomas
107
What is the diagnostic lab test for acromegaly?
Elevated insulin-like growth factor 1 (IGF-1)
108
What are the anesthesia implications of acromegaly?
* Distorted facial anatomy may interfere with mask placement * Enlarged tongue and epiglottis predispose to upper airway obstruction * Increased distance between the lips and vocal cords due to mandible overgrowth
109
What is diabetes insipidus (DI) caused by?
Vasopressin (ADH) deficiency
110
What are the two main types of diabetes insipidus?
* Central/Neurogenic DI * Nephrogenic DI
111
What is the initial treatment for neurogenic diabetes insipidus?
DDAVP
112
What can syndrome of inappropriate ADH result from?
* Intracranial tumors * Hypothyroidism * Porphyria * Lung cancer
113
What is the treatment for severe hyponatremia in syndrome of inappropriate ADH?
Hypertonic saline
