Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Clin Med Exam 3 > Diseases of the pituitary II - Comeau > Flashcards

Diseases of the pituitary II - Comeau Flashcards

1
Q

what hormones does the anterior pituitary release?

A
  • Growth Hormone (GH)
  • Prolactin (PRL) – for females for lactation
  • Adrenocorticotropic Hormone (ACTH)
  • Thyroid-stimulating Hormone (TSH)
  • Luteinizing Hormone (LH)
  • Follicle-stimulating Hormone (FHS)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what hormones does the posterior pituitary release?

A
  • Antidiuretic Hormone (ADH)

- Oxytocin – helps with giving birth (parturition) and lactation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is diabetes insipidus?

A

deficiency in vasopressin (ADH) from posterior pituitary (central DI)

OR

insensitivity to ADH (nephrogenic) - kidneys not responding to normal amount of ADH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the function of ADH? & what does deficiency of it mean?

A
  • ADH causes water preservation by the kidneys

- Deficiency of ADH means body does not hold onto water large amount of dilute urine produced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

when there is high amount of water in the blood, what is the urine output?

A

high b/c kidney starts to get rid of the excess water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

when there is low amount of water in the blood, what is the urine output?

A

low b/c kidney holds onto the water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

where is ADH created and excreted?

A

created by hypothalamus & excreted by posterior pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is diabetes insidious defined by?

A

passage of large volumes (>3L/24hr) of dilute urine (<300 mOsm/kg)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

2 major causes of diabetes insipidus?

A

central - decr secretion of ADH

nephrogenic - kidneys are not responding to normal amount of ADH (don’t reabsorb water)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

primary central DI vs secondary central DI?

A

Primary - no identifiable lesion on MRI of pituitary or hypothalamus (~1/3 cases)

Secondary - some type of damage to hypothalamus or pituitary stalk by trauma, infection, bleed, tumor, infarction (majority of cases)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

causes of primary central DI?

A

idiopathic (30%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

causes of secondary central DI?

A
  • Malignant or benign tumors of the pituitary (25%)
  • Cranial Surgery (20%)
  • Head Trauma (16%)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

nephrogenic causes of DI?

A
  • Lithium toxicity
  • Hypercalcemia (a lot of calcium in blood can cause kidney damage)
  • Demeclocycline – when treating this can cause diabetes insipidus
  • Steroids
  • Ofloxacin, methicillin
  • Pregnancy (Transient)
  • Renal disease (infection, amyloidosis, ATN, multiple myeloma)
  • Congenital
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

signs & symptoms of diabetes insipidus?

A

Clinical manifestations are caused by absence of ADH:

  • Polyuria
  • Polydipsia (b/c getting rid of all your water d/t polyuria)
  • Nocturia
  • Daily urinary output ranges from (3-20 liters/day)
  • Dehydration
  • Hypotension
  • Hypernatremia (increased Na+ in blood)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

diff dx for diabetes insipidus

A

-Diabetes Type I (similar symptoms)
-Hypercalcemia (% decreased kidney function can cause polyuria)
-Hypokalemia (can cause polyuria)
-Sickle cell anemia
-Psychogenic polydipsia
-Pregnancy Induced
(can occur in third trimester where circulating enzyme destroys vasopressin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

evaluation of diabetes insipidus?

A
  • 24hr urine collection (to see if having large amount of urine volume)
  • urinalysis
  • serum electrolytes & glucose
  • plasma and urine osmolality
  • ADH
  • water deprivation test +ADH
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

in diabetes insidious what will the serum Na & serum glucose be?

A

serum Na - HIGH

serum glucose - normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

in diabetes insidious what will the plasma and urine osmolality be?

A

Plasma osmolality – HIGH

Urine osmolality – LOW

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

in diabetes insidious what will the ADH be?

A
  • Central – LOW (b/c primary)

- Nephrogenic – HIGH (b/c body senses need more ADH and secretes more ADH, but kidneys not responding)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

for the water deprivation + ADH test, what will the results be for:

Central DI?
Nephrogenic DI?

A

Central DI – if urine osmolality increases to 750mOsm/kg
-In central DI, if you give them ADH that they’re lacking, their kidneys respond to it

Nephrogenic – no change
-If patient has nephrogenic cause of DI (more ADH), and give them ADH, won’t respond b/c already have ADH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what imaging will you do if you suspect central DI?

A

MRI of pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

txt for diabetes insipidus for severe symptoms?

A

Hypotonic solution D5W - reserved for pt with severe symptoms; need to reduce their serum sodium

must monitor electrolytes every 4-6hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

txt for central diabetes insipidus?

A

Desmopressin (DDAVP) Intranasal

  • Form of ADH
  • Kidneys working, problem in brain – just give patient back the ADH that’s not being secreted
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

txt for nephrogenic diabetes insipidus?

A

HCTZ – Diuretic that blocks reabsorption of Na+ into the kidneys will excrete Na

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is SIADH?

A

Syndrome of Inappropriate Antidiuretic Hormone

excessive release of antidiuretic hormone from the posterior pituitary gland

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what does excessive release of ADH cause?

A
  • renal tubule absorption of water and decrease urinary output
  • Causes water retention
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what does SIADH result in?

A
  • dilutional hyponatremia and low serum osmolality (b/c have so much water in the blood, the relative amount of salt to water is low)
  • Hyponatremia may be severe
  • Most common cause of hyponatremia in hospitalized patients
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what is the urine output and urine osmolality like in SIADH?

A

Decreased urinary output with increased urine osmolality

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

etiology of SIADH?

A
  • Head trauma
  • Malignancy (small cell lung cancer, pancreatic cancer)
  • Meningitis
  • Drugs (e.g, cyclophosphamide, clofibrate)
  • After pituitary surgery
  • Neurologic disorders
  • Psychiatric disorders
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

signs & symptoms of SIADH?

A

Symptoms are primarily the result of hyponatremia due to water intoxication

  • HA
  • N/V
  • Seizures
  • AMS
  • LOC
  • Asymptomatic – if development is gradual
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what determines the extent of symptoms of SIADH?

A

severity and onset of hyponatremia determine extent of symptoms (normal Na is 135-140)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

dx of SIADH

A

(Urine OSM HIGH & Plasma OSM LOW)

-Urinalysis – specific gravity is high
-Urine sodium – high
-Urine osmolality – high
-BMP – serum sodium low
-BUN – low
-Serum osmolality – low
ADH
-CT Head/MRI
-CXR
-CT Abd/Pelvis - ?malignancy b/c small cell lung cancer is common for this condition

33
Q

txt of SIADH if asymptomatic?

A
  • Restrict Fluid <1.5L/day
  • Discontinue offending medications
  • Demeclocycline – potent inhibitor of ADH (causes DI by increasing output of dilute urine)
34
Q

txt of SIADH if symptomatic (seizures, altered)?

A

3% NaCl (hypertonic solution)

  • Do not increase Na >0.5-1mEQ/L/hr
  • Check hourly serum sodium levels
  • Neuro critical care consult
35
Q

what is psychogenic polydipsia?

A
  • Clinical disorder characterized by polyuria and polydipsia
  • Common occurrence in inpatients with psychiatric disorders

NOT pathologic problem - happens clinically when patients have psychiatric disorders and drink a ton of fluid and urinate out a tone of fluid

Hyponatremia in these patients can progress to acute water intoxication

36
Q

management of psychogenic polydipsia? rule out what?

A

fluid restriction, behavioral and pharmacologic modalities

WANT TO RULE OUT PATHOLOGIC CAUSES BEFORE SAY IT’S RELATED TO THEIR PSYCHATRIC DISORDER

37
Q

what are the most common causes of dwarfism?

A

familial (genetic) and delayed (constitutional) growth -> both non-pathologic

38
Q

what is the goal of evaluation of dwarfism?

A

Goal of evaluation is to identify those children with pathologic causes and further evaluate growth trajectory and intervene when appropriate

39
Q

what is the height of dwarfism defined as?

A

height that is 2 standard deviations (SD) below mean for child of that sex and age

40
Q

what is the most common bone dysplasia in humans?

A

Achondroplasia

41
Q

what are the categories of Dwarfism? (HINT: 2)

A

proportionate dwarfism & disproportionate dwarfism

42
Q

what conditions are proportionate dwarfism?

A

Uniformed stunting of growth

Pituitary Dwarfism – GH hormone Deficiency Syndromes

Laron Syndrome

43
Q

what is uniformed stunning of growth caused by?

A

Caused by many metabolic/hormonal syndromes (e.g., Hypothyroidism, Turner’s Syndrome, nutritional deficiency, psychogenic hypopituitarism)

44
Q

what conditions are disproportionate dwarfism?

A

Achondroplasia (most common)

Sponydyloepiphyseal Dysplasia

Diastrophic dysplasia

45
Q

symptoms of Achondroplasia?

A

-Normal torso, short limbs
-Enlarged skulls
-Central apnea, obstructive apnea, and hydrocephalus
(central apnea b/c of oversized skull, the airway features can be abnormal)
-Difficult airway

46
Q

what is achondroplasia caused by?

A

autosomal dominant gene mutation that affects bone formation

shown to be associated w/advanced paternal age

47
Q

define sponyloepiphyseal dysplasia and what are the symptoms?

A
  • Adult height usually varying from slightly under 3 feet to slightly over 4 feet
  • Shortened trunk, barrel chest, club feet, cleft palate, severe osteoarthritis
  • SED is associated with a variety of medical problems, mainly orthopedic
48
Q

define diastrophic dysplasia and what are the symptoms?

A

-Rare, Autosomal Recessive

  • Shortened forearms and calves
  • Limited ROM
  • Cleft palate
  • Deformed Hands/Feet
  • At birth causes swelling of the pinna in the auricle of the ear
49
Q

how do you diagnose disproportionate dwarfism?

A

-Usually clinical diagnosis based on physical exam findings
-May do genetic testing
-May perform skeletal x-rays
(usually don’t do unless concerned about the patient)

50
Q

what is diagnostic if concerned about dwarfism?

A

skeletal x-rays

don’t usually perform unless concerned about the patient

51
Q

what is the treatment of disproportionate dwarfism?

A

Symptomatic relief:

  • Tracheotomy
  • Cleft palate repair
  • Leg braces
  • Back Braces
  • Club foot surgery
52
Q

what is pituitary dwarfism caused by?

A
  • GH deficiency (isolated deficiency)
  • Deficiency in growth hormone releasing hormone (GHRH)

-Can also occur with sellar and parasellar tumors that destroy the pituitary gland itself

53
Q

what is it imperative to do if suspected growth failure?

A

undertake detailed testing based on auxologicl criteria (study of human growth)

54
Q

signs & symptoms of pituitary dwarfism?

A
  • Severe postnatal growth failure
  • Delayed bone age
  • Hypoglycemia
  • Prolonged jaundice
  • Micropenis, high pitched voice, increase body fat, short stature
55
Q

what is the first step in diagnosing pituitary dwarfism?

A

The first step is to evaluate for other causes of growth failure, including chronic systemic disease, hypothyroidism, Turner syndrome (in girls), and skeletal disorders

56
Q

what do you do if there is no evidence of other causes for growth abnormality in pituitary dwarfism?

A

Order 3 diagnostic tests:

  • Insulin-like growth factor 1 (IFG-1)
  • Insulin-like growth factor binding protein 3 (IGFBP-3)
  • Bone age (skeletal imaging)
57
Q

when would you perform a GHD provocative test for pituitary dwarfism?

A

If serum concentrations of GH, IGF-1, and IGFBP-3 are low, clinical suspicion of GHD is high and nutritional deficiencies are excluded, provocative testing is required to confirm diagnosis

58
Q

what is the GHD provocative testing for pituitary dwarfism?

A
  • An agent that will normally provoke a pituitary to release a burst of GH
  • Blood is drawn @ 15 min intervals over one hour
  • Agents used (arginine, levodopa, clonidine, glucagon)

If serum concentrations of GH, IFG-1, and IGFBP-3 remain low, diagnosis can be confirmed

59
Q

why should an MRI be obtained in the evaluation of pituitary dwarfism?

A

MRI should also be obtained in the evaluation to rule out structural cause of GHD

60
Q

what is Laron syndrome?

A
  • Most common known cause of genetically mediated growth hormone insensitivity
  • Caused by mutations in GH receptor gene, unable to bind to receptor
  • causes severe postnatal growth failure
  • GH levels are normal or high (b/c body is stimulating GH)
61
Q

what are the GH levels like in Laron Syndrome?

A

GH levels are normal or high (b/c body is stimulating GH)

62
Q

clinical features of Laron Syndrome?

A

small head circumference, characteristic facies with saddle nose and prominent forehead

  • Delayed skeletal maturation
  • Small genitalia and testes
  • Short limb length compared with trunk length, and abnormal body composition
  • Osteopenia and obesity
63
Q

Turner syndrome cause?

A

missing X chromosome

64
Q

what is important to consider in females with short stature?

A

Turner syndrome

65
Q

what may be the only presenting symptoms of Turner syndrome?

A

short stature

66
Q

what are symptoms of Turner syndrome?

A

webbed neck, cubitus valgus, madelung deformity of the forearm

67
Q

why is important to promptly diagnosis Turner syndrome?

A
  • important b/c of associated cardiovascular, renal, and endocrine abnormalities, which may require treatment, including growth hormone therapy
  • Requires chromosomal analysis
68
Q

what is the treatment for pituitary deficient GH dwarfism?

A

Growth Hormone - replacing GH b/c deficient

69
Q

what is the treatment for Laron syndrome?

A

IGF-1 – b/c IGF is a growth hormone, problem isn’t that we don’t have growth hormone, but there is a mutation of the receptor so give IGF-1 to try and replace the GH

70
Q

what is Sheehan syndrome?

A

Infarction (death) of the Pituitary after postpartum hemorrhage
-Sower onset, but can be observed immediately postpartum with massive hemorrhage causing infarction immediately postpartum (less common)

71
Q

epidemiology of Sheehan syndrome?

A
  • Uncommon in developed countries

- Common cause of hypopituitarism in underdeveloped countries

72
Q

Signs & symptoms of severe Sheehan Syndrome (severe hypopituitarism)?

A

-Lethargy
-Anorexia
-Weight loss
-Inability to lactate during first days/weeks after delivery
(b/c once deliver baby, prolactin is released by the pituitary and if pituitary is dead then can’t lactate)

73
Q

is overt diabetes insidious rare in Sheehan syndrome?

A

no, it’s rare

74
Q

signs & symptoms of less severe Sheehan syndrome (less severe hypopituitarism)?

A
  • failure of postpartum lactation
  • failure to resume menses in the weeks/months after delivery
  • loss of sexual hair
  • milder fatigue, weight loss, anorexia
75
Q

what is the most immediate lab to determine when diagnosing Sheehan syndrome?

A

Corticotropin (ACTH) - MOST IMMEDIATE LAB TO DETERMINE B/C NEED TO EVALUATE ADRENAL INSUFFICIENCY IMMEDIATELY
(AM serum cortisol x2, abnormal cortisol -> low BP)

76
Q

other labs to determine when diagnosis Sheehan syndrome?

A

-Thyrotropin (TSH)
(Total thyroxine (T4) & triiodothyronine (T3) uptake or free T4)

  • Prolactin – serum prolactin level
  • Anti-diuretic hormone (ADH) – ADH level

Growth Hormone

  • Serum insulin-like growth factor 1 (IGF-1)
  • Growth hormone stimulation test

Gonadotropin

  • Men – serum total testosterone x 2 (8am to 10am) and Luteinizing hormone (LH)
  • Women – estradiol and follicle-stimulating hormone (FSH)
77
Q

diagnosis of Sheehan Syndrome?

A

Postpartum hypopituitary laboratory profile

  • must evaluate for adrenal insufficiency immediately
  • other hormonal deficiencies can be evaluated 4-6 weeks later

MRI

  • early abnormalities may be seen - enlargement/ischemia
  • late changes of small pituitary with normal size sella and eventually an empty sella (necrosis - looks like pituitary is not there)
78
Q

treatment of Sheehan Syndrome?

A

Treat for hormone deficiencies

  • Must treat for adrenal insufficiency
  • Other hormonal deficiencies can be related 4-6 weeks later

Prolactin deficiency results in inability to breast feed, but no treatment is available

If do have pregnant lady that has this syndrome make sure immediately that their blood volume is repleted and that they aren’t going to go into adrenal insufficiency – replacing cortisol is very important

79
Q

follow-up for Sheehan syndrome?

A
  • Continued monitoring for hormone deficiencies

- Monitor medical therapy

Clin Med Exam 3 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions