Health Ass 4: Endocrine Flashcards

Question

Under which condition might a random plasma glucose test be considered diagnostic for diabetes without requiring a second test for confirmation? A) HbA1c of 6.0% B) Presence of diabetes symptoms and a random plasma glucose ≥ 200 mg/dL C) Fasting plasma glucose of 126 mg/dL D) Two-hour plasma glucose of 140 mg/dL during an OGTT

Answer 1

Correct Answer: B) Presence of diabetes symptoms and a random plasma glucose ≥ 200 mg/dL Rationale: The presence of classic symptoms of hyperglycemia or a hyperglycemic crisis, along with a random plasma glucose level of 200 mg/dL or higher, can be used to diagnose diabetes without the need for a second test.

Answer 2

Correct Answer: B) Laboratory method NGSP certified and standardized to the DCCT assay Rationale: The ADA recommends that the laboratory method used for measuring HbA1c should be NGSP certified and standardized to the DCCT assay to ensure accuracy in diagnosing diabetes.

Answer 3

Correct Answer: D) Peripheral glucose uptake Rationale: Metformin primarily acts by enhancing glucose transport into tissues, improving peripheral insulin sensitivity, and decreasing hepatic glucose production. It does not stimulate insulin secretion nor directly cause β-cell regeneration.

Answer 4

Correct Answer: B) Hypoglycemia Rationale: Sulfonylureas increase insulin secretion, which can lead to hypoglycemia. Other side effects include weight gain and potential cardiac effects due to the risk of prolonged hypoglycemia.

Answer 5

Correct Answer:C) Reducing hepatic and peripheral insulin resistance Rationale: Lifestyle changes such as dietary adjustments and exercise leading to weight loss predominantly work by decreasing body fat, which improves hepatic and peripheral insulin sensitivity, reducing insulin resistance.

Answer 6

Correct Answer: B) Exhaustion of pancreatic β-cell function Rationale: Sulfonylureas stimulate insulin secretion, which can over time lead to β-cell exhaustion. As the disease progresses and β-cell function declines, sulfonylureas become less effective.

Answer 7

Correct Answer: B) Reduction in triglycerides (TGL) and low-density lipoprotein (LDL) cholesterol Rationale: Metformin has been shown to decrease levels of triglycerides and LDL cholesterol, which are beneficial cardiovascular effects beyond its glucose-lowering action. It is not typically associated with weight gain or appetite stimulation; in fact, it may aid in weight loss. Dr. David Sinclair's magic longevity drug.

Answer 8

Correct Answer: D. Thiazolidinediones Rationale: Thiazolidinediones are known to have an additional benefit of improving lipid profiles, particularly pioglitazone, which can be advantageous for patients with DM2 and coexisting dyslipidemia.

Answer 9

Correct Answer: C. Thiazolidinediones Rationale: Thiazolidinediones can lead to fluid retention and are associated with an increased risk of heart failure, which is a significant consideration in the management of DM2, especially in patients with a history of heart failure or other cardiovascular risks.

Answer 10

Correct Answer: B. GLP-1 receptor agonists Rationale: GLP-1 receptor agonists, such as semaglutide and dulaglutide, have been shown to reduce major adverse cardiovascular events, making them suitable for DM2 patients with high cardiovascular risk.

Answer 11

Correct Answer: B. SGLT-2 inhibitors Rationale: SGLT-2 inhibitors have demonstrated renal protective effects, with evidence showing improved renal outcomes in patients with DM2 and nephropathy. And acute kidney injury as a disadvantage.

Answer 12

Correct Answer: A. Rapid acting Rationale: Rapid-acting insulins, such as Lispro and Aspart, are designed to control glucose surges after meals, providing fast glucose control at mealtimes.

Answer 13

Correct Answer: B. No longer has autonomic or neuroglycopenic symptoms of hypoglycemia. Rationale: Repeated hypoglycemic episodes can lead to hypoglycemia unawareness, a condition where the patient becomes desensitized to low blood sugar levels and does not experience the typical warning symptoms, increasing the risk for severe hypoglycemia.

Answer 14

Correct Answer: C. Intramuscular (IM) or intravenous (IV) Rationale: When a patient has altered consciousness due to hypoglycemia, they cannot safely take oral glucose. Therefore, glucose should be administered intramuscularly or intravenously to rapidly increase blood glucose levels. Subcutaneous injection is not used in acute settings due to slower absorption.

Answer 15

Correct Answer: A. Alcohol consumption and use of ACE inhibitors Rationale: Alcohol (ETOH) can inhibit gluconeogenesis, and ACE inhibitors can increase insulin sensitivity, both potentially exacerbating the risk of hypoglycemia. The other options are less likely to cause hypoglycemia or may, in fact, be protective against it.

Answer 16

Correct Answer: C. Glargine (U-300) Rationale: Ultra-long-acting insulins, such as Glargine U-300, have an extended duration of action that can last up to 24 hours or more, providing a steady level of insulin, which is ideal for basal coverage. (note basal technically means intermediate acting)

Answer 17

Correct Answer: B. At the start of meals Rationale: Rapid-acting insulins like aspart and lispro are designed to be taken at mealtime because of their quick onset, matching the body’s immediate insulin needs post ingestion of food. 10-15 min onset, peak 1 hour.

Answer 18

Correct Answer: A. Their peak action time Rationale: Intermediate-acting insulins, such as NPH, have a peak action time where their effect is maximal. When switching from a long-acting insulin that provides a constant level of insulin, this peak must be considered to avoid hypoglycemia.

Answer 19

Correct Answer: C. The time at which insulin is at the highest concentration in the bloodstream Rationale: The peak of insulin action refers to the period when the insulin is at its maximum strength in terms of lowering blood glucose. This is an important consideration for timing insulin administration and anticipating potential hypoglycemia.

Answer 20

Correct Answer: D. Rapid-acting Rationale: Rapid-acting insulins, like lispro or aspart, have a quick onset of action, usually within 10-15 minutes, making them ideal for correcting high blood glucose levels shortly after administration. regular insulin is short acting w/ an onset time of 30 min, peak of 2-4 hr

Answer 21

Correct Answer: C. Osmotic diuresis due to hyperglycemia Rationale: In DKA, the high glucose levels exceed the renal threshold for reabsorption, leading to glucosuria which causes osmotic diuresis, and consequently, hypovolemia.

Answer 22

Correct Answer: C. Infection or illness Rationale: Infections or illness can increase stress hormone levels, which antagonize insulin action, and may precipitate the onset of DKA, especially in patients with DM1.

Answer 23

Correct Answer: C. Free fatty acids and ketone bodies Rationale: DKA involves the excessive production of ketone bodies due to increased lipolysis and free fatty acid metabolism in the liver, driven by insulin deficiency and counterregulatory hormone excess.

Answer 24

Correct Answer: C. Serum pH less than 7.3 Rationale: A serum pH less than 7.3 reflects an acidotic state, which is a hallmark of DKA due to the accumulation of ketoacids in the bloodstream.

Answer 25

Correct Answer: C. Intravenous short-acting insulin bolus Rationale: The initial treatment for DKA involves administering an intravenous bolus of short-acting insulin, usually regular insulin, at a dose of 0.1 units/kg, followed by a continuous infusion to lower blood glucose levels in a controlled manner.

Answer 26

Correct Answer: C. Potassium Rationale: Potassium is often supplemented during the treatment of DKA because insulin therapy promotes the uptake of potassium into cells and the osmotic diuresis associated with hyperglycemia leads to significant potassium losses.

Answer 27

Correct Answer: D. Cerebral edema Rationale: Rapid correction of hyperglycemia without the simultaneous correction of sodium can lead to cerebral edema. During treatment, it is crucial to monitor serum glucose and sodium levels and adjust the rate of glucose correction to reduce this risk.

Answer 28

Correct Answer: B. Correcting metabolic acidosis Rationale: Sodium bicarbonate is used in DKA treatment to correct the metabolic acidosis that results from the overproduction and accumulation of ketoacids in the blood.

Answer 29

Correct Answer: B. Type 2 Diabetes Mellitus over the age of 60 Rationale: HHS typically occurs in older individuals with Type 2 Diabetes Mellitus, evolving gradually over days to weeks, and is characterized by severe hyperglycemia, hyperosmolarity, and dehydration.

Answer 30

Correct Answer: A. Ketosis and fruity breath odor Rationale: Unlike diabetic ketoacidosis (DKA), HHS usually does not involve significant ketosis or the distinctive fruity breath odor caused by ketones, although patients can have some degree of acidosis.

Answer 31

C. Fluid resuscitation and gradual insulin therapy Rationale: The initial management of HHS focuses on fluid replacement to address severe dehydration and hyperosmolarity, followed by gradual insulin administration to correct hyperglycemia, avoiding rapid shifts that may lead to complications such as cerebral edema. fluid resuscitation, insulin bolus + infusion, e-lytes

Answer 32

Correct Answer: C. 30-40% Rationale: Diabetic nephropathy, a serious complication of diabetes, can progress to ESRD, with approximately 30-40% of individuals with DM1 being at risk. 5-10% develop ESRD

Answer 33

Correct Answer: B. Angiotensin-converting enzyme inhibitors (ACE-I's) Rationale: ACE inhibitors are used to slow the progression of proteinuria and the rate of GFR decline in patients with diabetic nephropathy. They have renoprotective effects that go beyond their ability to lower blood pressure.

Answer 34

Correct Answer: B. Hemodialysis (HD) and peritoneal dialysis (PD) Rationale: ESRD may be treated with various forms of dialysis, including hemodialysis and peritoneal dialysis, or ultimately with a kidney transplant - can combine w/ pancreas to prevent recurrence. Insulin therapy and strict glycemic control are important but not sufficient as sole treatments for ESRD.

Answer 35

Correct Answer: D. GFR < 15-20 mL/min Rationale: When the GFR falls below 15-20 mL/min, the kidneys' ability to excrete potassium is significantly impaired, resulting in hyperkalemia and metabolic acidosis.

Answer 36

Correct Answer: B. Pain and temperature perception changes in the toes/feet Rationale: Diabetic peripheral neuropathy typically begins with sensory deficits in the distal extremities, notably the toes and feet, often presenting as changes in pain and temperature perception.

Answer 37

Correct Answer: B. Optimal glycemic control Rationale: Optimal glycemic control is essential in the management of diabetic peripheral neuropathy, as it can slow the progression of neuropathy and potentially improve symptoms. Other treatments, such as NSAIDs, antidepressants, and anticonvulsants, can be used to manage pain and discomfort.

Answer 38

Correct Answer: B. Increased permeability and microaneurysm formation Rationale: Diabetic retinopathy is characterized by microvascular changes that lead to increased permeability, vessel occlusion, and microaneurysms in the retina, directly impacting vision.

Answer 39

Correct Answer: B. Unnoticed mechanical and traumatic injuries Rationale: Ulcers in diabetic peripheral neuropathy often result from mechanical and traumatic injuries that go unnoticed due to sensory deficits. These ulcers can lead to significant morbidity due to recurrent infections and risk of amputation. Loss of small nerve fibers decrease pain/temp perception, causing neuropathic pain

Answer 40

Correct Answer: C. Orthostatic hypotension Rationale: Autonomic neuropathy can damage the vasomotor fibers and baroreceptors, leading to ineffective cardiovascular responses such as orthostatic hypotension, where there's a significant drop in blood pressure upon standing.

Answer 41

Correct Answer: C. Gastroparesis resulting from decreased gastric motility Rationale: Diabetic autonomic neuropathy can cause a reduction in gastric secretions and motility, often leading to gastroparesis, which is characterized by delayed gastric emptying and associated symptoms like nausea, vomiting, and early satiety.

Answer 42

Correct Answer: C. Small, frequent meals and prokinetics Rationale: Treatment of gastroparesis and related symptoms involves improved glucose control, eating small, frequent meals to facilitate gastric emptying, and the use of prokinetic drugs to enhance gastrointestinal motility.

Answer 43

Correct Answer: B. To assess for the presence of silent myocardial ischemia Rationale: Diabetic autonomic neuropathy may blunt the typical symptoms of myocardial ischemia. Therefore, a stress test is indicated to detect any silent ischemic heart disease in diabetic patients, particularly those with additional cardiac risk factors or poor exercise tolerance.

Answer 44

Correct Answer: C. To avoid nephrotoxins and preserve renal blood flow (RBF) Rationale: Diabetic patients are at an increased risk for nephropathy. Adequate hydration helps to preserve renal function by maintaining renal blood flow and avoiding additional renal insults from nephrotoxic agents.

Answer 45

Correct Answer: B. There is a reduction in normal heart rate variability. Rationale: Autonomic neuropathy affects cardiovascular autonomic fibers, leading to decreased heart rate variability, which predisposes patients to perioperative cardiac dysrhythmias and hypotension.

Answer 46

Correct Answer: C. It increases the risk of aspiration pneumonia, regardless of nil per os (NPO) status. Rationale: Gastroparesis can delay gastric emptying, leading to increased gastric contents and volume, which increases the risk of aspiration during anesthesia, regardless of fasting status.

Answer 47

Correct Answer: B. Hypoglycemia with fasting, glucose <50 w/sx, sx relief with glucose Rationale: The Whipple's triad includes symptoms of hypoglycemia with fasting, documentation of low plasma glucose (<50 mg/dL) with symptoms, and relief of symptoms after administration of glucose, which is indicative of an insulinoma.

Answer 48

Correct Answer: B. To inhibit insulin release from beta cells and prevent hypoglycemia Rationale: Diazoxide is used preoperatively in patients with insulinoma because it inhibits insulin secretion from pancreatic beta cells, helping to prevent hypoglycemia before the tumor can be surgically removed.

Answer 49

Correct Answer: D. Surgery Rationale: Surgical removal of the insulinoma is curative, as these tumors are typically benign and isolated. Surgery addresses the underlying cause of the hypoglycemia by removing the tumor. Hypoglycemia can occur intra-op, followed by hyperglycemia once tumor removed. Tight glycemic control is paramount.

Answer 50

Correct Answer: A. Thyroid follicles Rationale: The thyroid follicles, composed of a layer of epithelial cells surrounding a lumen filled with colloid (primarily thyroglobulin), are the fundamental functional units of the thyroid gland where thyroid hormones are synthesized and stored.

Answer 51

Correct Answer: D. Calcitonin Rationale: Parafollicular C cells of the thyroid gland produce calcitonin, a hormone involved in the regulation of calcium and phosphate levels in the blood, counteracting the actions of parathyroid hormone (PTH).

Answer 52

Correct Answer: B. It is responsible for vocal cord movement and protection of the airway. Rationale: The recurrent laryngeal nerve innervates the intrinsic muscles of the larynx, controlling their movement. Injury to this nerve during thyroid surgery can lead to vocal cord paralysis and compromised airway protection. external motor branch of superior laryngeal nerve are in close proximity to the thyroid

Answer 53

Correct Answer: A. Thyroid peroxidase Rationale: Thyroid peroxidase (TPO) is the key enzyme in the thyroid hormone synthesis process, which catalyzes the iodination of tyrosine residues on thyroglobulin and the coupling of iodotyrosines to form thyroid hormones T3 and T4.

Answer 54

Correct Answer: C. Thyroxine-binding globulin Rationale: Thyroxine-binding globulin (TBG) is the primary carrier protein for thyroid hormones in the blood, binding up to 80% of T4. Prealbumin (transthyretin) and albumin also bind thyroid hormones, but to a lesser extent.

Answer 55

Correct Answer: C. To regulate metabolism and stimulate tissue development Rationale: Thyroid hormones play a pivotal role in metabolism, influencing virtually all metabolic processes. They are crucial for growth and development, tissue function, and the metabolism of proteins, carbohydrates, and fats.

Answer 56

Correct Answer: A. Oxidation to iodide in the GI tract Rationale: Dietary iodine is converted into iodide through an oxidation process in the gastrointestinal tract. This iodide is then rapidly absorbed into the bloodstream and transported to the thyroid follicular cells to be used in thyroid hormone synthesis.

Answer 57

Correct Answer: D. It protects against hormone depletion if synthesis is impaired. Rationale: The thyroid gland's large store of hormones and low turnover rate provide a reservoir that can maintain normal levels of thyroid hormones in the bloodstream for a period of time even if new hormone synthesis is disrupted, thus protecting against hypothyroidism.

Answer 58

Correct Answer: A. Thyroid-releasing hormone (TRH) Rationale: Thyrotropin-releasing hormone (TRH) is secreted by the hypothalamus and stimulates the anterior pituitary to release thyroid-stimulating hormone (TSH), which in turn stimulates the thyroid gland to produce thyroid hormones T3 and T4.

Answer 59

Correct Answer: D. High levels of T3 and T4 inhibit TSH release. Rationale: The production of thyroid hormones is regulated by a negative feedback loop. When the levels of T3 and T4 are high, they inhibit the release of TRH from the hypothalamus and TSH from the anterior pituitary, thus reducing thyroid hormone synthesis.

Answer 60

Correct Answer: D. Decreased T3 and T4 synthesis and decreased follicular cell size Rationale: A decrease in TSH results in decreased synthesis of T3 and T4, as well as reduced follicular cell size and gland vascularization, due to the reduced stimulation of the thyroid gland.

Answer 61

Correct Answer: B. To bind to receptors on thyroid cell membranes and enhance T3 and T4 secretion Rationale: TSH binds to specific receptors on the membranes of thyroid cells and stimulates the synthesis and secretion of the thyroid hormones T3 and T4.

Answer 62

Correct Answer: B. Thyroid autoregulation Rationale: The thyroid gland has an autoregulatory mechanism that adjusts the synthesis and release of thyroid hormones to maintain consistent hormone levels, independent of TSH regulation.

Answer 63

Correct Answer: B. To assess the functional state of the pituitary gland in secreting TSH Rationale: The TRH stimulation test is used to evaluate the function of the pituitary gland by administering thyrotropin-releasing hormone and measuring the subsequent secretion of TSH, thereby assessing the pituitary's capacity to respond to hypothalamic input.

Answer 64

Correct Answer: C. It reflects the sensitivity of the hypothalamic-pituitary-thyroid axis to small changes in thyroid hormone levels. Rationale: The normal range of TSH (0.4-5.0 milliunits/L) reflects the tight regulation of thyroid function by the hypothalamic-pituitary-thyroid axis, where even small changes in thyroid hormone levels can lead to significant changes in TSH secretion

Answer 65

Correct Answer: C. The nodule is producing an excess of thyroid hormone. Rationale: In thermal imaging of the thyroid, a "hot" nodule is one that shows increased uptake of the radioactive tracer, indicating "hyperfunctioning" tissue that is producing an excess of thyroid hormone. warm is normal functioning

Answer 66

Correct Answer: C. To determine whether a thyroid lesion is cystic, solid, or mixed in composition Rationale: Ultrasonography is highly accurate (90-95%) in differentiating the physical composition of thyroid lesions, which is critical for determining the nature of the lesion and guiding further diagnostic or therapeutic steps.

Answer 67

Correct Answer: B. Graves' disease Rationale: Graves' disease is an autoimmune disorder and one of the most common causes of hyperthyroidism, characterized by the overproduction of thyroid hormones. major diseases: Graves disease toxic multinodular goiter toxic adenoma

Answer 68

Correct Answer: C. Sweating, heat intolerance, and fatigue Rationale: The symptoms of hyperthyroidism, such as sweating, heat intolerance, and fatigue, are due to the hypermetabolic state induced by excessive thyroid hormones.

Answer 69

Correct Answer: C. Acts directly on the myocardium and peripheral vasculature to cause cardiovascular responses Rationale: T3 has a direct effect on the myocardium and peripheral vasculature, leading to increased heart rate, contractility, and vasodilation, contributing to the cardiovascular manifestations of hyperthyroidism such as tachycardia and palpitations.

Answer 70

Correct Answer: B. Fine tremor of hands Rationale: Fine tremor of the hands is a common neurologic manifestation of hyperthyroidism, often associated with the hypermetabolic state that accelerates various physiologic processes.

Answer 71

Correct Answer: C. Increased heart rate and enhanced contractility Rationale: A hyperdynamic cardiac state in hyperthyroidism refers to increased heart rate (tachycardia) and myocardial contractility, which leads to increased cardiac output.

Answer 72

Correct Answer: B. Frequent bowel movements or diarrhea Rationale: Hyperthyroidism often causes an increase in gastrointestinal motility, resulting in symptoms such as frequent bowel movements or diarrhea.

Answer 73

Correct Answer: C. Emotionally unstable Rationale: Hyperthyroidism can cause various psychological symptoms, including emotional instability, anxiety, and mood swings.

Answer 74

Correct Answer: B. Females, 20-40 years old Rationale: Graves' disease typically occurs in females, with a female-to-male ratio of about 7:1, and most commonly presents in individuals between 20-40 years of age.

Answer 75

Correct Answer: C. Thyroid-stimulating hormone receptor antibody (TSHR-Ab) Rationale: Graves' disease is characterized by the presence of thyroid-stimulating antibodies that bind to and activate the TSH receptors, leading to thyroid growth, increased vascularity, and hypersecretion of thyroid hormones.

Answer 76

C. Exophthalmos Rationale: Ophthalmopathy associated with Graves' disease often manifests as exophthalmos, which is the protrusion of the eyeballs. This can occur in approximately 30% of cases and is due to inflammation and edema in the orbital tissues.

Answer 77

Correct Answer: B. Inspiratory stridor Rationale: Severe enlargement of the thyroid gland in Graves' disease can lead to compression of the trachea, which may present with inspiratory stridor, a high-pitched wheezing sound indicative of airway obstruction. also, dysphagia, globus sensation

Answer 78

Correct Answer: B. Antithyroid medications such as methimazole or propylthiouracil (PTU) Rationale: The initial treatment for Graves' disease typically involves antithyroid medications like methimazole or propylthiouracil (PTU), which help to reduce the production of thyroid hormones.

Answer 79

Correct Answer: C. By impeding the peripheral conversion of T4 to T3 Rationale: Beta-blockers, such as propranolol, are used in the symptomatic management of Graves' disease because they can block the peripheral conversion of T4 to the more active T3, and they provide symptomatic relief from adrenergic symptoms like tachycardia and palpitations.

Answer 80

Correct Answer: C. Hypoparathyroidism Rationale: Complications from thyroid surgery can include hypothyroidism, hemorrhage with tracheal compression, damage to the recurrent laryngeal nerve (RLN), and damage to or inadvertent removal of the parathyroid glands, which can lead to hypoparathyroidism.

Answer 81

Correct Answer: C. When medical treatment has failed to control the disease Rationale: Ablative therapy or surgery is recommended for patients with Graves' disease when medical treatment with antithyroid drugs is not successful in managing the disease, or in cases where rapid control of hyperthyroidism is necessary, such as thyroid storm or in preparation for surgery.

Answer 82

Correct Answer: C. 6-8 weeks Rationale: For elective surgical cases in patients with Graves' disease, it is generally recommended to wait 6-8 weeks to allow for antithyroid drugs to take effect and stabilize thyroid hormone levels.

Answer 83

Correct Answer: C. To evaluate for evidence of tracheal compression or deviation caused by a goiter Rationale: The preoperative assessment of the upper airway in patients with Graves' disease is important to identify any anatomical deviation or compression of the trachea by an enlarged thyroid gland (goiter), which could complicate airway management during surgery.

Answer 84

Correct Answer: B. IV beta-blockers, glucocorticoids, and propylthiouracil (PTU) Rationale: In emergent situations, such as thyroid storm or when urgent surgery is required, intravenous beta-blockers, glucocorticoids, and propylthiouracil (PTU) are administered to quickly control hyperthyroid symptoms and stabilize the patient.

Answer 85

Correct Answer: B. To optimize the thyroid state and minimize the risk of thyroid storm during surgery Rationale: Establishing and optimizing thyroid hormone levels preoperatively in patients with Graves' disease is critical to reduce the risk of perioperative complications, including the potentially life-threatening thyroid storm.

Answer 86

Correct Answer: C. Trauma or infection Rationale: A thyroid storm is a life-threatening exacerbation of hyperthyroidism that can be precipitated by stressors such as trauma, infection, medical illness, or surgery, especially when the hyperthyroid state is not well-controlled.

Answer 87

Correct Answer: C. Thyroid storm can be associated with a history of thyroid disease. Rationale: Differentiation between thyroid storm and malignant hyperthermia is challenging due to similar clinical presentations. However, a history of thyroid disease and specific triggers may help distinguish thyroid storm. Thyroid storm is associated with a history of hyperthyroidism and can occur spontaneously or be precipitated by a stressor, whereas malignant hyperthermia is typically triggered by specific anesthetic agents.

Answer 88

Correct Answer: B. Thyroid storm Rationale: Thyroid storm is a critical condition that can occur postoperatively, especially in patients with untreated or inadequately treated hyperthyroidism who undergo emergency surgery.

Answer 89

Correct Answer: B. Rapid alleviation of thyrotoxicosis and supportive care Rationale: The treatment of thyroid storm focuses on the rapid alleviation of thyrotoxicosis through antithyroid medications, supportive care to stabilize vital functions, and management of the precipitating factors.

Answer 90

Correct Answer: C. 20% Rationale: Despite aggressive treatment, the mortality rate for thyroid storm is high, historically around 20%, due to the severe systemic effects of this condition.

Answer 91

Correct Answer: C. Ablation of the thyroid gland Rationale: The most common cause of primary hypothyroidism in areas with sufficient iodine intake is ablation of the thyroid gland, typically due to treatment for hyperthyroidism with radioactive iodine or surgery.

Answer 92

Correct Answer: D. Idiopathic hypothyroidism Rationale: Idiopathic hypothyroidism, which is often thought to be autoimmune in nature, can be associated with the presence of antibodies that block TSH receptors, leading to decreased production of T3 and T4 despite normal or elevated TSH levels.

Answer 93

Correct Answer: B. Middle-aged women Rationale: Hashimoto's thyroiditis is an autoimmune thyroid disorder more commonly diagnosed in middle-aged women and is characterized by a goitrous enlargement of the thyroid gland and hypothyroidism.

Answer 94

Correct Answer: C. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) Rationale: SIADH, which can present with hyponatremia and fluid overload, is a common extrathyroidal manifestation of hypothyroidism.

Answer 95

Correct Answer: B. Slowing of motor function and prolonged relaxation phase of deep tendon reflexes Rationale: Neurologic manifestations of hypothyroidism include slow speech, general slowing of motor functions, and a prolonged relaxation phase following deep tendon reflexes, reflecting the overall slowing of metabolic processes in the body.

Answer 96

Correct Answer: B. Flattened or inverted T waves Rationale: Hypothyroidism can affect the heart, often leading to specific changes on an ECG, such as flattened or inverted T waves, low-amplitude P waves, and sometimes bradycardia and ventricular dysrhythmias.

Answer 97

Correct Answer: C. Pale, cool, dry thickened skin, nonpitting peripheral edema Rationale: Hypothyroidism can cause a variety of skin changes, including pale, cool, and dry thickened skin, often accompanied by nonpitting peripheral edema, which is commonly referred to as myxedema.

Answer 98

Correct Answer: C. Reduced levels of T3, T4, and TSH Rationale: Secondary hypothyroidism is characterized by low levels of T3 and T4, as well as TSH, indicating a pituitary or hypothalamic origin of the disorder rather than a primary thyroidal defect.

Answer 99

Correct Answer: C. 20% Rationale: Approximately 20% of women over the age of 60 have subclinical hypothyroidism, a condition with an elevated TSH level but normal thyroid hormone levels, which can be associated with an increased risk of coronary artery disease if TSH is greater than 10 milliunits/L.

Answer 100

Correct Answer: B. No response of TSH to administered TRH Rationale: A TRH stimulation test can confirm a pituitary cause of hypothyroidism if there is no increase in TSH levels following the administration of TRH, which would normally stimulate the pituitary to release TSH.

Answer 101

Correct Answer: B. Low T3 & T4 with normal TSH level Rationale: Euthyroid sick syndrome, also known as nonthyroidal illness syndrome, is characterized by abnormal thyroid function tests, like low T3 and T4, in the absence of intrinsic thyroid disease, typically with a normal TSH level. It is seen in critically ill patients and is often a response to acute stress such as surgery, illness, or fasting.

Answer 102

Correct Answer: C) L-Thyroxine Rationale: L-Thyroxine is the synthetic form of the thyroid hormone thyroxine and is the treatment of choice for hypothyroidism. It is essential in perioperative management to ensure euthyroid state and minimize the risk of myxedema coma, which can be precipitated by surgery and anesthesia.

Answer 103

Correct Answer: B) Slower gastric emptying increasing risk of aspiration Rationale: Hypothyroidism can lead to decreased gastrointestinal motility, resulting in slower gastric emptying. This condition increases the risk of aspiration during anesthesia induction. Preoperative fasting guidelines may need to be adjusted, and the use of prokinetic agents may be considered.

Answer 104

Correct Answer: B) Hypodynamic cardiovascular system Rationale: Patients with hypothyroidism often present with a hypodynamic cardiovascular system, characterized by decreased heart rate and cardiac output, which can affect hemodynamic management during anesthesia.

Answer 105

Correct Answer: D) Begin L-thyroxine therapy at least 10 days before surgery Rationale: It is recommended to start L-thyroxine at least 10 days before elective surgery to achieve a euthyroid state and reduce the risks associated with hypothyroidism during surgery. This timeframe allows for adequate stabilization of thyroid hormone levels.

Answer 106

Correct Answer: B) Electrolyte imbalances Rationale: Hypothyroid patients are more prone to electrolyte imbalances, such as hyponatremia, which can be exacerbated by the stress of surgery and anesthesia. Careful monitoring and correction of electrolytes are vital to avoid perioperative complications. If emergent surgery: IV Thyroid replacement along with steroids ASAP

Answer 107

Correct Answer: B) IV L-Thyroxine Rationale: Intravenous L-Thyroxine is the initial treatment of choice for myxedema coma. It can also be supplemented with L-Triiodothyronine in certain clinical situations given the urgent need for the restoration of thyroid hormone levels, considering the high mortality associated with myxedema coma.

Answer 108

Correct Answer: B) Elderly women with a long history of hypothyroidism Rationale: Myxedema coma is most commonly seen in elderly women with a long-standing history of hypothyroidism. This is due to physiological changes associated with aging and a potentially decreased ability to adapt to the hypothyroid state.

Answer 109

Correct Answer: B) Correction of electrolyte imbalances Rationale: Electrolyte imbalances, particularly severe hyponatremia, are common in myxedema coma and must be carefully corrected along with other supportive measures such as mechanical ventilation if required, and stabilization of cardiac and pulmonary systems.

Answer 110

Correct Answer: B) Hypothermia Rationale: Hypothermia is a cardinal sign of myxedema coma due to impaired thermoregulation. Thyroid hormones play a significant role in thermogenesis and metabolism, and their deficiency leads to a decreased heat production.

Answer 111

Correct Answer: C) Usually within 24 hours Rationale: Heart rate, blood pressure, and temperature typically show improvement within 24 hours after initiating appropriate treatment, which includes intravenous thyroid hormone replacement and supportive care. However, complete recovery may take longer and depends on the severity of the condition and promptness of the treatment.

Answer 112

Correct Answer: B) L-thyroxine supplementation Rationale: Most goiters, especially those associated with a compensated euthyroid state, are treated with L-thyroxine supplementation. This treatment can help reduce the size of the goiter by inhibiting thyroid-stimulating hormone (TSH) secretion through the feedback mechanism on the pituitary gland.

Answer 113

Correct Answer: B) Ingestion of goitrogenic substances Rationale: Goiter can be caused by the ingestion of goitrogenic substances found in foods like cassava, or drugs such as phenylbutazone and lithium, which can interfere with thyroid hormone synthesis or release, leading to thyroid gland hypertrophy and hyperplasia.

Answer 114

Correct Answer: C) When medical therapy is ineffective and there are cosmetic or airway concerns Rationale: Surgical intervention for goiter is considered when medical therapy with L-thyroxine is ineffective and if the goiter compromises the airway (AW) or is cosmetically unacceptable to the patient.

Answer 115

Correct Answer: C) Euthyroidism Rationale: Although goiters can occur in various thyroid states, most cases of goiter are associated with a compensated euthyroid state, where the thyroid function tests are within normal ranges despite the gland enlargement.

Answer 116

Correct Answer: B) Hypertrophy and hyperplasia of follicular epithelium Rationale: The enlargement of the thyroid gland in goiter is due to hypertrophy and hyperplasia of the follicular epithelium. This is often a compensatory response to inadequate thyroid hormone production or increased TSH stimulation.

Answer 117

Correct Answer: A) Risk of airway (AW) obstruction during general anesthesia (GA) Rationale: Dyspnea in different body positions in a patient with goiter is suggestive of positional airway obstruction and is an important consideration in the preoperative evaluation, as it may predict airway compromise during anesthesia, necessitating careful airway management.

Answer 118

Correct Answer: B) CT scan Rationale: A CT scan of the neck and thorax is crucial for assessing the extent of a thyroid tumor, its anatomical relationship with surrounding structures, and planning for surgery or other treatments by providing detailed cross-sectional images.

Answer 119

Correct Answer: B) Assess the site and degree of airway obstruction Rationale: Flow-volume loops, performed in both upright and supine positions, are a pulmonary function test used to determine the site and degree of airway obstruction, which can be crucial in preoperative planning for patients with goiter.

Answer 120

Correct Answer: C) Extra-thoracic airway obstruction Rationale: Limitations in the inspiratory limb of the flow-volume loop suggest an extra-thoracic airway obstruction, which is consistent with conditions that compress or narrow the airway outside the thoracic cavity, such as a large goiter.

Answer 121

Correct Answer: B) The degree of cardiac compression by a goiter Rationale: Echocardiography in different positions is useful in assessing the degree of cardiac compression, which can occur with large goiters, and helps to evaluate the impact of the thyroid mass on cardiac structures and function.

Answer 122

Correct Answer: B) 13% Rationale: Morbidity from thyroid surgery, which includes any complications arising from the procedure, approaches 13%. This encompasses a range of possible complications such as recurrent laryngeal nerve injury, hypoparathyroidism, and hematoma.

Answer 123

Correct Answer: B) Voice changes and hoarseness Rationale: Unilateral RLN injury after thyroid surgery most commonly results in hoarseness due to impaired vocal cord movement. Complete airway obstruction is rare with unilateral involvement, and recovery of function generally occurs within 3-6 months if the nerve has not been transected.

Answer 124

Correct Answer: C) In the first 24-48 hours postoperatively Rationale: Symptoms of hypocalcemia can manifest in the first 24-48 hours postoperatively due to inadvertent damage to the parathyroid glands during thyroid surgery. Prompt recognition and treatment of this complication are crucial to prevent severe symptoms.

Answer 125

C) Hematoma causing tracheal compression

Answer 126

Correct Answer: C) Airway obstruction and possible need for tracheostomy Rationale: Bilateral RLN injury is a more serious complication than unilateral injury as it may cause airway obstruction and difficulty coughing, which can be life-threatening and may warrant a tracheostomy.

Answer 127

Correct Answer: C) Inadvertent damage to the parathyroid glands Rationale: Hypoparathyroidism post-thyroidectomy is often the result of inadvertent damage to or removal of the parathyroid glands, leading to hypocalcemia, which typically presents in the first 24-48 hours after surgery.

Answer 128

Correct Answer: C) Observation and readiness to manage potential tracheal compression due to hematoma Also, laryngospasm from hypocalcemia Rationale: After thyroid surgery, there is a risk of hematoma formation that can compress the trachea. Hence, there should be vigilance and readiness to manage this, including keeping a tracheostomy set at the bedside during the immediate postoperative period.

Answer 129

Correct Answer: B) Glucocorticoids, mineralocorticoids, and androgens Rationale: The adrenal cortex synthesizes and secretes glucocorticoids (e.g., cortisol), mineralocorticoids (e.g., aldosterone), and androgens. The adrenal medulla, in contrast, is responsible for the production of catecholamines such as epinephrine and norepinephrine.

Answer 130

Correct Answer: B) Adrenocorticotropic hormone (ACTH) Rationale: ACTH, released from the anterior pituitary gland, stimulates the adrenal cortex to produce cortisol. This is part of the hypothalamic-pituitary-adrenal (HPA) axis.

Answer 131

Correct Answer: B) Increases blood glucose by stimulating gluconeogenesis Rationale: Cortisol induces hyperglycemia, reflecting its role in gluconeogenesis (the formation of glucose from non-carbohydrate sources) and the inhibition of glucose uptake by cells, which helps to provide energy in response to stress.

Answer 132

Correct Answer: A) They cause sodium retention and potassium excretion. Rationale: Cortisol has some mineralocorticoid activity and can contribute to sodium retention, while aldosterone specifically promotes sodium retention and potassium excretion in the kidneys, affecting fluid and electrolyte balance.

Answer 133

Correct Answer: B) In the adrenal medulla Rationale: The adrenal medulla is responsible for the conversion of norepinephrine to epinephrine. This conversion is facilitated by cortisol, which is produced in the adrenal cortex.

Answer 134

Correct Answer: D) Chromaffin cells Rationale: Pheochromocytomas are tumors that secrete catecholamines and arise from chromaffin cells of the sympathoadrenal system, specifically located within the adrenal medulla.

Answer 135

Correct Answer: B) Hypertension, cerebrovascular accident (CVA), and myocardial infarction (MI) Rationale: Excessive catecholamine release from pheochromocytomas can lead to malignant hypertension, which increases the risk of acute cardiovascular events such as stroke (CVA) and myocardial infarction (MI).

Answer 136

Correct Answer: A) 85:15 Rationale: Most pheochromocytomas secrete catecholamines with a predominance of norepinephrine (NE) over epinephrine (EPI) at a ratio of approximately 85:15, which is the inverse of the normal adrenal secretion where epinephrine is more predominant.

Answer 137

Correct Answer: C) 18% Rationale: Approximately 18% of pheochromocytomas occur in the organ of Zuckerkandle, which is a collection of chromaffin cells located at the abdominal aorta bifurcation. The majority, however, are found in the adrenal medulla.

Answer 138

Correct Answer: B) 24-hour urine collection for metanephrines and catecholamines Rationale: A 24-hour urine collection for metanephrines and catecholamines is a key diagnostic test for pheochromocytoma, as it measures the byproducts of catecholamine metabolism, which are typically elevated in this condition.

Answer 139

Correct Answer: D) Ultrasound Rationale: While ultrasound can be used to image the adrenal glands, CT scans and MRI are preferred for their superior detail. I-metaiodobenzylguanidine (MIBG) scintigraphy is a specific type of nuclear medicine scan used to localize catecholamine-secreting tumors like pheochromocytoma.

Answer 140

Correct Answer: C) Headache, sweating, and orthostatic hypotension Rationale: Classic symptoms of pheochromocytoma are often summarized as the '5 Ps': pressure (hypertension), pain (headache), perspiration (sweating), palpitations, and pallor, including orthostatic hypotension due to volume depletion.

Answer 141

Correct Answer: D) Mitral valve prolapse Rationale: While pheochromocytoma can lead to serious cardiac issues such as coronary vasoconstriction, cardiomyopathy, and congestive heart failure due to the effects of excessive catecholamines, mitral valve prolapse is not typically associated with it.

Answer 142

Correct Answer: C) Occasional to frequent, ranging from 1 minute to several hours Rationale: Attacks of pheochromocytoma can range from occasional to frequent and may last from as little as one minute to several hours. They may occur spontaneously or be triggered by factors such as injury, stress, or medications.

Answer 143

Correct Answer: B) To lower blood pressure and decrease intravascular volume Rationale: The preoperative use of an α blocker in pheochromocytoma patients is to lower blood pressure and decrease intravascular volume, which helps prevent intraoperative hypertensive episodes and decreases the risk of myocardial dysfunction due to excessive catecholamine stimulation

Answer 144

Correct Answer: B) Noncompetitive α1 antagonist with some α2-blocking properties Rationale: Phenoxybenzamine is a noncompetitive α1 antagonist that irreversibly binds to the receptor and also possesses some α2-blocking properties. This makes it a long-acting agent suitable for preoperative management of pheochromocytoma.

Answer 145

Correct Answer: C) Treat with a beta-blocker (BB) Rationale: If tachycardia occurs after α blockade, it is appropriate to treat it with a beta-blocker. However, beta-blockers should never be used before adequate α blockade to avoid unopposed α agonism and subsequent hypertensive crisis.

Answer 146

Correct Answer: B) It leads to unopposed α agonism, causing vasoconstriction and hypertensive crises Rationale: Administering a nonselective beta-blocker before α blockade can lead to unopposed α agonism because of the loss of β2-mediated vasodilation. This can result in severe vasoconstriction and hypertensive crises, which are dangerous in patients with pheochromocytoma.

Answer 147

Correct Answer: B) Control hypertension Rationale: CCBs are used in the management of pheochromocytoma primarily to control hypertension. They work by inhibiting the entry of calcium into cells, which reduces the force of contraction of the heart and dilates the arteries. Excessive calcium can trigger catecholamine release from the tumor and contribute to cardiomyopathy, which CCBs help to prevent.

Answer 148

Correct Answer: C) ACTH-independent Cushing’s syndrome has suppressed CRH and ACTH levels due to autonomous cortisol secretion. Rationale: ACTH-independent Cushing’s syndrome is characterized by excessive cortisol production by abnormal adrenocortical tissue that is not regulated by corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH), resulting in suppressed levels of these hormones.

Answer 149

Correct Answer: B) Small cell lung carcinoma Rationale: Acute ectopic ACTH syndrome is most often associated with small cell lung carcinoma, where the cancer cells produce ACTH, leading to ACTH-dependent Cushing’s syndrome.

Answer 150

Correct Answer: C) Adrenocortical tumors Rationale: Benign or malignant adrenocortical tumors are the most common cause of ACTH-independent Cushing's syndrome. These tumors produce cortisol independently of ACTH regulation.

Answer 151

Correct Answer: B) It stimulates the adrenal cortex to produce excessive cortisol. Rationale: In ACTH-dependent Cushing’s syndrome, high levels of plasma ACTH stimulate the adrenal cortex to produce excessive cortisol, leading to the clinical manifestations of Cushing's syndrome.

Answer 152

Correct Answer: C) Suppressed ACTH response Rationale: In ACTH-independent Cushing's syndrome, because the source of excess cortisol is autonomous adrenal cortical tissue, CRH and ACTH levels are typically suppressed. An ACTH stimulation test would not increase cortisol levels further in this scenario.

Answer 153

Correct Answer: C) 24-hour urine cortisol test Rationale: The 24-hour urine cortisol test is used to confirm the diagnosis of Cushing's syndrome as it measures the total cortisol excreted in the urine over a 24-hour period, which is elevated in Cushing's syndrome.

Answer 154

Correct Answer: D) Low plasma ACTH and high cortisol levels Rationale: In Cushing's syndrome, cortisol production can be elevated independent of plasma ACTH levels. In ACTH-independent Cushing's syndrome, cortisol levels are high despite low or suppressed ACTH levels, due to autonomous adrenal cortisol production.

Answer 155

Correct Answer: B) It helps to distinguish between Cushing's disease and ectopic ACTH syndrome. Rationale: The high-dose dexamethasone suppression test is used to differentiate between Cushing's disease (pituitary-dependent Cushing's syndrome) and ectopic ACTH syndrome. Cushing's disease will typically show a response to high-dose dexamethasone with a decrease in cortisol production, whereas ectopic ACTH production (e.g., from a lung tumor) usually will not be suppressed by dexamethasone.

Answer 156

Correct Answer: A) Exophthalmos Rationale: Exophthalmos, or protruding eyes, is not a typical feature of Cushing's syndrome. The classic symptoms of Cushing's syndrome include central obesity with a rounded "moon face," muscle wasting, thinning of the skin with easy bruising (ecchymoses), hypertension, glucose intolerance, and neuropsychiatric disturbances like depression and insomnia.

Answer 157

Correct Answer: C) Immunoradiometric assay Rationale: Reliable measurements of plasma ACTH using immunoradiometric assays are essential when determining whether Cushing's syndrome is ACTH dependent or independent. This assay is particularly sensitive and specific for ACTH, helping to discern the source of hypercortisolism.

Answer 158

Correct Answer: B) Transsphenoidal microadenomectomy Rationale: Transsphenoidal microadenomectomy is the treatment of choice for resectable pituitary microadenomas causing Cushing's syndrome. This approach is minimally invasive and allows for the removal of the tumor through the sphenoid sinus, minimizing brain tissue disruption.

Answer 159

Correct Answer: C) When pituitary irradiation fails or is not an option Rationale: Bilateral total adrenalectomy may be necessary when other treatments, such as pituitary irradiation, fail or are not suitable. This is often the case in ACTH-dependent Cushing's syndrome when the source cannot be controlled, resulting in continued overproduction of cortisol by the adrenal glands.

Answer 160

Correct Answer: B) Blood pressure, electrolyte balance, and blood glucose Rationale: Preoperative evaluation for a patient with Cushing’s syndrome must include careful assessment and stabilization of blood pressure, electrolyte imbalances (especially hypokalemia), and elevated blood glucose levels, as these can significantly impact perioperative risk and anesthetic management.

Answer 161

Correct Answer: C) Risk for pathologic fractures due to osteoporosis Rationale: When positioning a patient with Cushing’s syndrome for surgery, it’s important to consider the increased risk for pathologic fractures due to osteoporosis. Careful positioning and padding are necessary to prevent fractures in these patients who may have fragile bones.

Answer 162

Correct Answer: C) Surgical adrenalectomy Rationale: Surgical removal of the adrenal gland(s), or adrenalectomy, is indicated for Cushing’s syndrome caused by adrenal adenomas or carcinomas to remove the source of excessive cortisol production.

Answer 163

Correct Answer: B) A functional adrenal tumor Rationale: Primary hyperaldosteronism, also known as Conn's syndrome, is most commonly caused by a functional adrenal tumor (aldosteronoma) that secretes aldosterone independently of the usual regulatory mechanisms.

Answer 164

Correct Answer: D) Hypothyroidism Rationale: Primary hyperaldosteronism is occasionally associated with other endocrine disorders, such as pheochromocytoma, hyperparathyroidism, and acromegaly. Hypothyroidism is not commonly associated with it.

Answer 165

Correct Answer: B) Increased serum renin Rationale: Secondary hyperaldosteronism is characterized by the overproduction of aldosterone due to an external stimulus, most commonly increased serum renin, which can be due to conditions such as renal artery stenosis or congestive heart failure.

Answer 166

Correct Answer: A) Hypertension Rationale: One of the main symptoms of hyperaldosteronism is hypertension, which is often accompanied by hypokalemia and metabolic alkalosis. This is due to the effect of aldosterone on the renal tubules, where it promotes sodium retention and potassium excretion.

Answer 167

Correct Answer: A) Hypokalemic metabolic alkalosis Rationale: Hyperaldosteronism typically leads to hypokalemia and metabolic alkalosis. This results from the action of aldosterone increasing sodium reabsorption and potassium excretion in the kidneys, which also leads to the excretion of hydrogen ions, causing alkalosis.

Answer 168

Correct Answer: A) Primary hyperaldosteronism Rationale: Spontaneous hypokalemia in the presence of systemic hypertension is highly suggestive of hyperaldosteronism, particularly primary hyperaldosteronism, where there is excessive aldosterone production leading to increased renal potassium loss and sodium retention, causing hypertension.

Answer 169

Correct Answer: B) Suppressed Rationale: In primary hyperaldosteronism, plasma renin activity is typically suppressed due to the negative feedback mechanism; the high aldosterone level causes sodium retention and hypertension, which decreases the release of renin.

Answer 170

Correct Answer: A) Licorice Rationale: Long-term ingestion of licorice can cause a syndrome that mimics the features of hyperaldosteronism. Licorice contains glycyrrhizic acid, which can inhibit the enzyme 11β-hydroxysteroid dehydrogenase type 2, resulting in features such as hypertension, hypokalemia, and suppression of the renin-angiotensin-aldosterone system (RAAS).

Answer 171

Correct Answer: C) Spironolactone Rationale: Spironolactone is a competitive aldosterone antagonist used in the treatment of hyperaldosteronism. It blocks the effects of aldosterone on the renal tubules, thereby mitigating the potassium loss and hypertension associated with this condition.

Answer 172

Correct Answer: B) Adrenalectomy Rationale: Surgical removal of the adrenal gland, or adrenalectomy, may be the definitive treatment for an aldosterone-producing tumor in hyperaldosteronism. This would eliminate the source of excessive aldosterone secretion and potentially cure the condition.

Answer 173

Correct Answer: C) Hypoaldosteronism Rationale: Hyperkalemia in the absence of renal insufficiency is suggestive of hypoaldosteronism, where there is inadequate production or secretion of aldosterone, leading to decreased excretion of potassium by the kidneys.

Answer 174

Correct Answer: C) Hyperglycemia Rationale: Hyperkalemia may be enhanced by hyperglycemia. High blood sugar can cause a shift of potassium out of cells into the bloodstream, exacerbating the hyperkalemia already present in hypoaldosteronism.

Answer 175

Correct Answer: B) Hyperchloremic metabolic acidosis Rationale: Hypoaldosteronism often leads to hyperchloremic metabolic acidosis due to impaired renal acid secretion and a decrease in sodium reabsorption, which aldosterone normally promotes.

Answer 176

Correct Answer: B) Indomethacin-induced prostaglandin deficiency Rationale: Indomethacin can cause reversible hypoaldosteronism due to its effect on prostaglandin synthesis. Prostaglandins can affect aldosterone secretion, and their deficiency may lead to reduced aldosterone levels.

Answer 177

Correct Answer: C) Liberal sodium intake and administration of fludrocortisone Rationale: Treatment of hypoaldosteronism often includes liberal sodium intake to counteract the loss of sodium due to lack of aldosterone, and fludrocortisone, a synthetic mineralocorticoid, to replace the deficient aldosterone and promote sodium reabsorption and potassium excretion by the kidneys.

Answer 178

Correct Answer: A) Primary adrenal insufficiency Rationale: Primary adrenal insufficiency, also known as Addison's disease, occurs when the adrenal glands are damaged and unable to produce sufficient amounts of glucocorticoids, mineralocorticoids, and androgens.

Answer 179

Correct Answer: C) Autoimmune adrenalitis Rationale: The most common cause of primary adrenal insufficiency in developed countries is autoimmune destruction of the adrenal cortex, which is often referred to as autoimmune adrenalitis.

Answer 180

Correct Answer: B) Aldosterone Rationale: Secondary adrenal insufficiency usually involves only a glucocorticoid deficiency because aldosterone secretion is primarily regulated by the renin-angiotensin system, not by ACTH.

Answer 181

Correct Answer: A) Hyperpigmentation Rationale: Hyperpigmentation is a characteristic finding in primary adrenal insufficiency due to elevated levels of ACTH, which also stimulates melanocytes. This is typically absent in secondary adrenal insufficiency, as ACTH levels are low or normal.

Answer 182

Correct Answer: A) Long-term use of synthetic glucocorticoids Rationale: Long-term use of synthetic glucocorticoids is a common iatrogenic cause of secondary adrenal insufficiency. It can suppress the hypothalamic-pituitary axis, leading to reduced production of CRH and ACTH, and ultimately decreased cortisol production by the adrenal glands.

Answer 183

Correct Answer: C) Adrenal insufficiency Rationale: A baseline cortisol level of less than 20 µg/dL that remains low after ACTH stimulation indicates adrenal insufficiency. This shows that the adrenal cortex is not responding adequately to ACTH, suggesting an impairment of adrenal function.

Answer 184

Correct Answer: B) The adrenal glands show a poor or no increase in cortisol production in response to ACTH Rationale: A positive ACTH stimulation test in the context of adrenal insufficiency means that there is a poor response to ACTH, which is demonstrated by a lack of significant increase in cortisol levels after administration of synthetic ACTH.

Answer 185

Correct Answer: B) Low baseline cortisol level with no response to ACTH Rationale: Absolute adrenal insufficiency is characterized by a low baseline cortisol level and a lack of response (or a minimal increase in cortisol levels) to the ACTH stimulation test. (positive)

Answer 186

Correct Answer: D) Higher baseline cortisol level with a positive ACTH stimulation test Rationale: Relative adrenal insufficiency is indicated when the baseline cortisol level is higher compared to absolute adrenal insufficiency, but there is still a positive ACTH stimulation test indicating inadequate response of the adrenal glands to ACTH.

Answer 187

Correct Answer: C) Steroids Rationale: The treatment for adrenal insufficiency typically involves replacement of the deficient steroids, most commonly glucocorticoids such as hydrocortisone, and in the case of primary adrenal insufficiency, mineralocorticoids such as fludrocortisone are also replaced.

Answer 188

Correct Answer: C) Behind the upper and lower poles of the thyroid gland Rationale: The four parathyroid glands are typically located behind the upper and lower poles of the thyroid gland, where they produce parathyroid hormone (PTH) in response to plasma calcium levels.

Answer 189

Correct Answer: B) Maintain normal plasma calcium levels Rationale: Parathyroid hormone (PTH) is essential in maintaining normal plasma calcium levels. It does so by promoting the movement of calcium across the gastrointestinal tract, renal tubules, and bone.

Answer 190

Correct Answer: B) Hypocalcemia Rationale: Hypocalcemia stimulates the release of PTH as part of a negative feedback mechanism. PTH then acts to correct the low calcium levels by increasing calcium reabsorption and mobilization from bone.

Answer 191

Correct Answer: B) It suppresses PTH synthesis and release. Rationale: Hypercalcemia suppresses the synthesis and release of PTH, reducing its actions on calcium mobilization, absorption, and reabsorption, to help lower plasma calcium levels to normal.

Answer 192

Correct Answer: C) It increases calcium reabsorption. Rationale: PTH acts on the renal tubules to increase calcium reabsorption, which helps to elevate or maintain the plasma calcium level. PTH also increases the excretion of phosphate by the kidneys, preventing the formation of insoluble calcium phosphate, which would otherwise precipitate in tissues.

Answer 193

Correct Answer: A) Benign parathyroid adenoma Rationale: Benign parathyroid adenoma is the most common cause of primary hyperparathyroidism, accounting for approximately 90% of cases.

Answer 194

Correct Answer: D) Hypocalcemia Rationale: Hyperparathyroidism is typically associated with hypercalcemia, not hypocalcemia. Symptoms often related to hyperparathyroidism include sedation, nausea/vomiting, reduced strength and sensation, polyuria, renal stones, peptic ulcer disease (PUD), and cardiac disturbances due to high calcium levels.

Answer 195

Correct Answer: B) Plasma calcium and 24-hour urinary calcium Rationale: The diagnosis of hyperparathyroidism is confirmed by measuring plasma calcium and 24-hour urinary calcium levels. Elevated calcium with high or inappropriately normal PTH levels and increased urinary calcium excretion are indicative of the disease.

Answer 196

Correct Answer: B) Surgical removal of abnormal parathyroid tissue Rationale: The treatment of choice for primary hyperparathyroidism, especially when symptomatic or causing complications, is the surgical removal of the abnormal parathyroid tissue.

Answer 197

Correct Answer: C) Hypocalcemia secondary to chronic renal failure (CRF) Rationale: Secondary hyperparathyroidism is a compensatory response of the parathyroid glands to chronic hypocalcemia, which is commonly seen in conditions such as chronic renal failure (CRF). It is the parathyroid glands' attempt to normalize calcium levels.

Answer 198

Correct Answer: B) It results from a separate disease process that causes hypocalcemia, not from overproduction of PTH. Rationale: Secondary hyperparathyroidism is adaptive and serves to counteract hypocalcemia. It is due to a separate disease process that causes hypocalcemia, like chronic renal failure, so the increased PTH production is a response to this and usually does not produce hypercalcemia.

Answer 199

Correct Answer: B) Administering a phosphate binder Rationale: Treatment for secondary hyperparathyroidism, particularly in the context of renal disease, includes normalizing phosphate levels by administering a phosphate binder. This helps reduce phosphate levels, which can contribute to hypocalcemia and thus drive secondary hyperparathyroidism.

Answer 200

Correct Answer: B) Hypoparathyroidism Rationale: Hypoparathyroidism is characterized by low plasma calcium levels along with low levels of PTH, which is responsible for regulating calcium levels in the body. When PTH is deficient, calcium levels fall, leading to the symptoms associated with hypocalcemia.

Answer 201

Correct Answer: D) Hyperreflexia Rationale: Chronic hypocalcemia is associated with symptoms such as fatigue, cramps, lethargy, cataracts, subcutaneous calcifications, thickening of the skull, and neurologic deficits. Hyperreflexia is typically not a feature of chronic hypocalcemia; it is more commonly associated with conditions that cause hypercalcemia or electrolyte imbalances affecting nerve excitability.

Answer 202

Correct Answer: B) A congenital disorder where PTH is adequate, but kidneys are unable to respond to it Rationale: Pseudohypoparathyroidism is a congenital disorder characterized by a normal or increased PTH level with end-organ resistance, particularly in the kidneys, resulting in features similar to hypoparathyroidism despite adequate levels of the hormone.

Answer 203

Correct Answer: B) Chronic renal failure (CRF) Rationale: Chronic renal failure (CRF) is the most common cause of chronic hypocalcemia. In CRF, the kidneys are less able to convert vitamin D to its active form and excrete phosphate, leading to reduced calcium absorption and retention of phosphate, which further lowers calcium levels.

Answer 204

Correct Answer: C) Calcium and Vitamin D replacement Rationale: The mainstay of treatment for hypoparathyroidism is calcium and vitamin D replacement to correct hypocalcemia and maintain normal serum calcium levels. Vitamin D helps increase calcium absorption from the gut, and calcium supplementation helps directly increase serum calcium levels.

Answer 205

Correct Answer: B) Sella turcica Rationale: The pituitary gland is located within a bony structure called the sella turcica at the base of the brain.

Answer 206

Correct Answer: C) Vasopressin and oxytocin Rationale: Vasopressin (antidiuretic hormone) and oxytocin are synthesized in the hypothalamus and then transported down the pituitary stalk to be stored and released by the posterior pituitary gland.

Answer 207

Correct Answer: C) Osmoreceptor sensing in the hypothalamus Rationale: The stimulus for the release of hormones from the posterior pituitary gland, specifically vasopressin, arises from osmoreceptors in the hypothalamus that sense changes in plasma osmolarity.

Answer 208

Correct Answer: C) Adrenocorticotropic hormone (ACTH) Rationale: Cushing's syndrome is often associated with the hypersecretion of ACTH due to anterior pituitary adenomas. The excess ACTH stimulates the adrenal cortex to overproduce cortisol, leading to the clinical manifestations of Cushing's syndrome.

Answer 209

Correct Answer: A) Anterior pituitary Rationale: The anterior pituitary secretes hormones under the direct control of the hypothalamus through a specialized vascular system known as the hypophyseal portal system. This system allows hypothalamic hormones to regulate the activity of the anterior pituitary gland.

Answer 210

Correct Answer: C) Elevated serum insulin-like growth factor 1 (IGF-1) Rationale: Serum insulin-like growth factor 1 (IGF-1) is elevated in acromegaly and serves as a key diagnostic marker since it reflects the increased secretion of growth hormone (GH), typically due to a pituitary adenoma.

Answer 211

Correct Answer: B) Oral glucose tolerance test (OGTT) with measurement of GH levels Rationale: The oral glucose tolerance test (OGTT) measures plasma growth hormone levels after ingestion of 75g glucose. In healthy individuals, glucose ingestion suppresses GH levels, but in acromegaly, the GH level remains elevated above 1 ng/mL.

Answer 212

Correct Answer: A) Upper airway (AW) obstruction Rationale: The overgrowth of soft tissues in acromegaly can make patients more susceptible to upper airway obstruction due to the enlargement of the airway tissues and structures.

Answer 213

Correct Answer: C) Hoarseness and vocal cord abnormalities Rationale: Hoarseness and abnormal movement of vocal cords, or even recurrent laryngeal nerve (RLN) paralysis, may result from the overgrowth of the surrounding cartilaginous structures in patients with acromegaly.

Answer 214

Correct Answer: C) Transsphenoidal surgical excision of the adenoma Rationale: The first-line treatment for a pituitary adenoma causing acromegaly is usually transsphenoidal surgical excision of the pituitary adenoma. If surgery not feasible, tx is a LA somatostatin analogue

Answer 215

Correct Answer: C) Distorted facial anatomy and upper airway structures may complicate intubation Rationale: Patients with acromegaly may have distorted facial anatomy due to overgrowth of facial bones and soft tissues, including an enlarged tongue and epiglottis. These changes can interfere with the placement of a face mask and visualization of vocal cords during direct laryngoscopy (DL), making airway management more challenging.

Answer 216

Correct Answer: C) Increased distance between the lips and vocal cords complicating intubation Rationale: In acromegaly, an enlarged tongue and epiglottis can predispose to upper airway obstruction and make it difficult to visualize the vocal cords during direct laryngoscopy. The increased distance between the lips and vocal cords due to mandibular overgrowth can further complicate intubation.

Answer 217

Correct Answer: B) Use of a smaller ETT and potential use of video laryngoscopy (VL) or awake fiberoptic intubation Rationale: Due to the potential for difficult airway management in patients with acromegaly, there may be a need for a smaller endotracheal tube (ETT) and advanced intubation techniques such as video laryngoscopy (VL) or awake fiberoptic intubation to secure the airway safely.

Answer 218

Correct Answer: C) It may narrow the glottic opening Rationale: Vocal cord enlargement, which can occur in acromegaly, may narrow the glottic opening. This can complicate intubation by making it difficult to pass the endotracheal tube through the vocal cords and necessitating the use of a smaller diameter tube.

Answer 219

Correct Answer: B) Destruction of posterior pituitary or hypothalamus leading to vasopressin deficiency Rationale: Neurogenic DI reflects a deficiency in vasopressin (antidiuretic hormone, ADH) due to damage or destruction of the posterior pituitary gland or hypothalamus, resulting in the inability to concentrate urine.

Answer 220

Correct Answer: C) By response to desmopressin administration Rationale: Neurogenic and nephrogenic DI are differentiated based on the response to desmopressin, a synthetic analogue of vasopressin. In neurogenic DI, desmopressin will decrease urine output and increase its osmolality, but in nephrogenic DI, the renal tubules are unresponsive to desmopressin, and there is little to no change in urine output or osmolality.

Answer 221

Correct Answer: B) Polydipsia and polyuria Rationale: Both forms of DI present with polydipsia (excessive thirst) and polyuria (high output of poorly concentrated urine), despite increased serum osmolarity, due to the body's inability to conserve water without the effects of ADH.

Answer 222

Correct Answer: B) IV fluids (electrolytes) to offset polyuria Rationale: The initial treatment for DI involves administration of IV fluids (electrolytes) to replace the large urine volume loss due to polyuria and to prevent dehydration.

Answer 223

Correct Answer: A) Urine output (UOP) and serum electrolyte concentrations Rationale: During anesthesia, it is critical to monitor urine output and serum electrolyte concentrations in patients with DI, as they are prone to significant fluid and electrolyte imbalances due to their condition.

Answer 224

Correct Answer: B) Intracranial tumors and hypothyroidism Rationale: SIADH can occur in the presence of various pathologies, including intracranial tumors, hypothyroidism, porphyria, and lung carcinoma, which can cause an inappropriate secretion of antidiuretic hormone (ADH).

Answer 225

Correct Answer: B) Increased urinary sodium and decreased serum osmolality Rationale: In SIADH, the laboratory findings typically include inappropriately increased urinary sodium excretion and a decrease in serum osmolality in the presence of hyponatremia, which is not appropriate for the serum osmolality.

Answer 226

Correct Answer: B) Cerebral edema and seizures Rationale: Abrupt decreases in serum sodium concentration can cause an osmotic imbalance across the blood-brain barrier, leading to cerebral edema and potentially causing seizures.

Answer 227

Correct Answer: C) Demeclocycline Rationale: Demeclocycline is an ADH antagonist that is used in the treatment of SIADH. It reduces the action of ADH on the renal tubules, which can help correct the water retention and hyponatremia seen in SIADH.

Answer 228

Correct Answer: A) Hypertonic saline hypertonic saline @ <8 mEq/L over 24-hrs Rationale: Severe hyponatremia in SIADH may be treated with hypertonic saline, especially when serum sodium is critically low (<120 mEq/L) and/or the patient is symptomatic. The infusion rate should be carefully controlled to avoid overly rapid correction, which can lead to osmotic demyelination syndrome.

Health Ass 4: Endocrine Flashcards

(253 cards)