Brainscape's Knowledge GenomeTM

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


See full index

Medicine 1 VCS860 > Parathyroid Disorders > Flashcards

Parathyroid Disorders Flashcards

1
Q

Calcium homeostasis

Ionized Calcium

A

this is the physiologically active fraction and ionized calcium is maintained within a fairly narrow range.

This fraction 44-50% of total calcium in the normal patient

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

Calcium Homeostasis

Bound Calcium

A

typically bound to albumin in serum

Inactive form of calcium

50-55% of total calcium in the normal patient

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

Calcium Homeostasis

Complexed calcium

A

accounts for less than 1-2% of total calcium.

In chronic renal failure, retention of sunstances such as citrate and oxalate tht form calcium complexes elevate the total calcium without affecting ionized calcium

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

parathyroid Hormone

A

principle hormone that affects IONIZED CALCIUM

secreted by the parathryoid glands, which are in proximity to the thyroid gland.

Dogs and Cats have 4 parathyroid glands.

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

Parathyroid Hormone Effects

A

decreases renal calcium excretion

Increases renal phosphorous excretion

Increases calcium and phosphorous mobilization from bone

Stimulates production of 1.25-dihydroxycholecalciferol (VitD). increases bone calcium and phosphorous via enhanced intestinal uptake and bone mobilization

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

Primary Hyperparathyroidism

A

occurs in both dogs and cats

in dogs, among the common causes of sever hypercalcemia.

In cats, primary hyperparathyroidism is uncommon

In both species, primary hyperparathyroidism is typically caused by a single parathyroid adenoma

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

Priamry Hyperparathyroidism

Diagnosis

A

confrimed by documenting elevated serum PTH and ionized calcium

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

Hyperparathyroidism is characterized by

A

HYPERCALCEMIA

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

Clinical signs of Hypercalcemia

A

often mild or absent

GI: common - anorexia, vomiting, constipation; Less common - Pancreatitis

Renal: PU/PD, possible stranguria/pollakiuria form stone formation

CNS: mental dullness, obtundation, coma, shivering, twitching, seizures

Muscle: Weakness

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

Calcitonin

A

Hormone released by the thyroid gland that reduces blood calcium levels

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

Differential diagnosis: Hyperparathyroidism

Hypercalcemia of malignancy

A

MOST COMMON cause in dogs

Tumors commonly associated with hypercalcemia include: Lymphosarcoma, Multiple Myeloma, Apocrine gland Carcinoma, leukemias, mammary gland carcinoma, thymoma,

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

Differential diagnosis: Hyperparathyroidism

Hypercalcemia of malignancy

Diagnosis

A

dependent on appropriate imaging/FNA/Biopsy procedures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Differential diagnosis: Hyperparathyroidism

Idiopathic Hypercalcemia in Cats

A

Mild to moderate hypercalcemia that occurs in young/middle-aged cats

Ionized calcium is increases

NO ABNORMALITIES in PTH, PTH-rp, VitD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Differential diagnosis: Hyperparathyroidism

Hypervitaminosis D

A

Typically hypercalcemia is present with hyperphophotemia in VitD toxicosis

Cholecalciferol rodenticide is a mojor cause of this disorder.

Toxicosis becomes severe within 48-72 hours,

Other sources: dermatologic ointments for people, over-supplementation of a patient with hypoparathyroidism, cestrum diurnum (daily blooming Jessamine) toxicosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Differential diagnosis: Hyperparathyroidism

Hypoadrenocortisism

A

serum calcium willbe increased in 30-50% of dogs/cats

Typically correlates well with serum potassium levels,

Not clinically important

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

Differential diagnosis: Hyperparathyroidism

Chronic Renal Failure

A

Renal secondary hyperparathyroidism is a well-recognized phenomenon in chronic renal failure

results as a suppression of ionized calcium form the presence of hyperphophatemia

THESE PATIENTS NEVER HAVE ELEVATED IONIZED CALCIUM

total calcium may be elevated, not physiologically important to the patient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Differential diagnosis: Hyperparathyroidism

Miscellaneous

A

bacterial/fungal osteomyelitis

blastomycosis

histoplasmosis

Schistosomiasis

Coccidiodomycosis

Sepsis

hypothermia

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

Differential diagnosis: Hyperparathyroidism

Laboratory error:

A

Lipemia

Hemoconcentration

hemolysis

ALL can falsely elevate serum total calcium

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

Hyperparathyroidism

Physical Examination

A

PE often unremarkable

Occasionally, careful palpation of hte neck may reveal a nodule

20
Q

Hyperparathyroidism

Diagnostic Imaging

A

Parathyroid nodule detected by ultrasound of hte neck is supportive, but not diagnostic for hyperparathyroidism.

Nodules may only be found after surgical exploration

21
Q

Hyperparathyroidism

Laboratory Evaluation

A

Chemistry: elevation in total calcium and ionized calcium levels, Phosphorous is low

22
Q

Hyperparathyroidism

Laboratory Evaluation

Inconsistent with Hyperparathyroidism

Cytopenia

A

suppressiono fone or more cell types (RBC, WBC, Platelets) on the CBC may be associated with bone marrow infiltration in patitents with leukemia or lymphosarcoma

23
Q

Hyperparathyroidism

Laboratory Evaluation

Inconsistent with Hyperparathyroidism

Serum Globulin Level

A

marked elevations with multiple myeloma and some lymphomas

24
Q

Hyperparathyroidism

Laboratory Evaluation

Inconsistent with Hyperparathyroidism

BUN/Creatinine

A

Can be elevated in chornic renal failure, secondary to renal mineralization from prolonged hypercalcemia

or prerenal form PU with depressed fliud intake

25
Q

Hyperparathyroidism

Laboratory Evaluation

Inconsistent with Hyperparathyroidism

Phosphorous

A

Important to measure in all hypercalcemia cases

Usually low or low-normal as a result of increased PTH, PTH-rp

Hyperphophatemia without azotemia is more suggestive for VitD toxicosis or there nonparathyroid causes

26
Q

Hyperparathyroidism

Laboratory Evaluation

Inconsistent with Hyperparathyroidism

Potassium and Sodium Concentrations

A

Hyperkalemai and hyponatremia in combination suggest hypoadrenocorticism

27
Q

Medical therapy for severe hypercalcemia

any cause

A

treat:

dehydration

azotemia

cardiac arrhythmias

severe neurologic dysfunciton

weakness

28
Q

Acute therapy of hypercalcemia

Useful in all cases

A

fluid therapy

0.9% NaCl

saline diuresis promites renal calcium loss

29
Q

Acute Therapy for Hypercalcemia

Useful in some cases

Furosemide

A

increases renal calcium excretion along with enhanced sodium excretion.

inhibits Ca2+ resorption in the loop of henle.

30
Q

Acute therapy for hypercalcemia

useful in some cases

Glucocorticoids

A

if possible, avoid the use of GC until a diagnosis has been established.

GC decreases calcium resporption from bone, decreases intestinal Ca2+ absorption, increase renal Ca2+ excretion

31
Q

Primary Hypoparathyroidism

A

occurs in dogs and cats but is much less common than Hyperparathyroidism

32
Q

Major causes of Hypoparathyroidism

A

lumphocytic parathyroiditis, iatrogenic damage/removal of the parathyroid gland during thyroid surgery, as complication of parathyroidectomy for hyperparathyroidism

33
Q

Hypoparathyroidism is characterized by

A

HYPOcalcemia

34
Q

Hypocalcemia

A

infrequently recognized problem in dogs and cats

increases tissue excitabliity in nervous and muscle tissue.

signs are caused by a decrease in ionized calcium concentrations

35
Q

Effects of Hypocalcemia

A

peripheral neuromuscular signs - tetany (prolonged muscle spasm)

Cardiac signs - poor cardiac systolic function, cardiac dilation, bradycardia. Prolonged S-T, Q-T segments

Neurologic sings - extrapyramidal neurologic syndromes and increased intracranial pressure

Ocular - papilledema

36
Q

Other causes of Hypocalcemia

A

chronic renal fialure

acute pancreatitis

puerperal tetany (Eclampsia)

Intestinal malabsorption

Nutritional hypoparathyroidism

Acute renal fialure from Ethylene Glycol Toxicity

Iatrogenic phosphate toxicity

37
Q

Hypocalcemia due to hypoabluminemia

A

serum total calcium is often decreased in patients with hypoabluminemia.

bound pool of calcium is decreased

38
Q

How to correct calcium measurement with hypoalbumiemia

A

corrected calcium = measured total Ca + (3.5-albumin)

39
Q

Hypoparathyroidism

Physical Exam

A

nervousness

seizures

muscle cramping or pain (usually rear limbs)

Focal muscle fasiculation / twitching

Ataxia, stiff gait

Intense facial rubbing, biting / licking at paws

Aggression

Panting

Weakness

Inappetence. listlessness, depression

40
Q

Hypoparathyroidism

Diagnostic imaging

A

Generally not used to make a diagnosis

41
Q

Hypoparathyroidism

Laboratory Evaluation

A

Most obvious finding ishte presence of severe hypocalcemia on the serum biochemistry profile.

Measurement of ionized calcium may be helpful to confirm hypocalcemia when the total calcium is not obviously low.

Phosphorous level is elevated

42
Q

Results consistent with a diagnosis of Primary Hypoparathyroidism

A

decreased serum PTH, decreased ionized and total calcium. VIt D levels typically low

43
Q

Comparison with Hypercalcemia disorders

A
44
Q

Treatment of Hypoparathyroidism

Emergency therapy

A

intravenous calcium

given IV slowly over 10-20 minutes

Monitor ECG during administration and briefly discontinue infusion if bradycardia develops

45
Q

Treatment of Hypoparathyroidism

Maintenance therapy

Immediate

A

Repeated IV bolus injections NOT recommended

Continuous IV infusion

SQ calcium: AVOID if possible

46
Q

Treatment of Hypoparathyroidism

Maintentace therapy

long term

A

vitamin D2

Dihydrotachysterol (DHT)

Calcitriol

Oral calcium supplementation

Medicine 1 VCS860 (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions