Endocrine Flashcards
chemistries related to endocrine
electrolytes and hormones
electrolytes related to endocrine
Na: hyponatremia seen in renal failure, vomiting, diarrhea, use of diuretics, excessive ADH, CHF, water toxicity, excessive fluid administration
K+: hyperkalemia seen in adrenal cortical hypofunction, late stage renal failure, and acidosis
hormones related to endocrine
thyroxine (T4) functions: increases cell metabolism, affects growth/development, reproduction, resistance to infection
triiodothyronine (T3): produced by thyroid gland through deiodination of T4, has more biologic activity
TSH: helps sustain thyroid gland and stimulates it to produce T3 and T4
TRH (thyrotropin-releasing hormone): triggers TSH release
glucagon: increases serum sugar concentration
insulin: decreases serum sugar concentration
common endocrine diseases
thyroid (hyper/hypo), diabetes mellitus, hyperadrenocorticism, hypoadrenocorticism
hyperthyroidism basics
common in cats
98% of cases are caused by benign functional thyroid adenoma, 2% of cases are caused by malignant thyroid carcinoma
hyperthyroidism feedback loop
hypothalamus produces TRH (thyrotropin-releasing hormone) — TRH stimulates pituitary gland to release TSH — TSH stimulates thyroid gland to produce T3/T4 — T3/T4 go into the serum
hyperthyroidism CS
weight loss, polyphagia, vomiting, diarrhea, polydipsia, tachypnea, hyperactivity, dyspnea, aggression, thickened nails
metabolism is increased so you will most likely see an angry/hyperactive cat that is losing weight and eating a ton
hyperthyroidism dx
total T4 (measures all T4 in body: bound and unbound), free T4 (best!!, measures only unbound T4), T3 suppression test, TRH stim test
hyperthyroidism tx
thyroidectomy (careful not to mess with parathyroid gland –> hypocalcemia
radioactive iodine, meds (methimazole decreases production of T3/T4, pill or transdermal 2 times a day), diet (Hill’s y/d iodine free diet)
anything outside of surgery or radioactive iodine needs B/W done every 2-3 weeks for 3 months, then annual or bi-annually
hypothyroidism basics
common in dogs
autoimmune - body attacking thyroid gland causing decreased T3/T4 production or can be idiopathic
hypothyroidism CS
decreased activity levels, increased body weight, skin/haircoat changes (alopecia, hair thinning, hyperpigmentation), tragic facial expression, reproductive failure (no heat), bradycardia, megaesophagus
hypothyroidism dx
total T4, free T4, TSH levels, TRH stim test
total T4 is ideal and confirm with free T4
sick euthyroid syndrome
patient could show a decreased T4 on blood work if animal is sick but the animal doesn’t have hypothyroidism
confirm by doing another T4 when animal is healthy
what is an important thing to know about medicine for hypothyroidisim?
human hypothyroid meds are in mcg but dog hypothyroid meds are in mg
can not give a dog human meds!!
hypothyroidism tx
supplement thyroid hormones
Levothyroxine
do bloodwork every 6 weeks for 6-8 months then annually or bi-annually
do bloodwork 6 hours after patient takes a pill
diabetes mellitus (DM) basics
disorder of fat, carbs, and protein metabolism caused by absolute or relative insulin deficiency
beta cells secrete insulin
alpha cells secrete glucagon
type 1: pancreas doesn’t produce insulin
type 2: cells don’t respond to insulin properly
often seen concurrent with pancreatitis
diabetes cell insulin mechanics
when there is glucose floating through the blood, pancreas beta cells secrete insulin — insulin binds to an insulin receptor on a cell and the cell becomes more permeable to glucose — glucose from the bloodstream can now flow into the cell and give it energy to perform its functions in the body
diabetes CS
polyphagia, polyuria, polydipsia, sweet breath, weight loss, lethargy, cataracts (dogs)
can see plantigrade stance in cats (will be on flat feet on hindlegs, whole part of leg distal to hock will be flat on ground) – caused by weakness in muscle tissue = diabetic neuropathy
normal blood glucose level
70-140 mg/dL
diabetes dx
blood sample
can’t tell you which type of diabetes
make sure to spin the sample right after it clots in serum separator tube so the cells don’t eat up all the glucose and lead to false negative
diabetes tx
insulin SQ BID, titrated to effect
types of insulin: rapid absorbed - R on label, regular insulin
intermediate acting - NPH, N, or Lente “L” on label
long acting - U or PZI on label
glucose curve
used to monitor blood glucose levels, measures fructosamine levels
prick for blood or do blood draw
take baseline — eat — insulin — test every 2-4 hours
glucose curve should go down, hit nadir, then climb back up
one curve is complete when it hits nadir
insulin not working anymore when the curve climbs back up
client education for diabetes
teach client proper dose and how to admin insulin, proper storage/mixing of insulin, diet and when to admin, when not to admin
diabetic ketoacidosis (DKA) basics
when carbs aren’t available cells will go after fats/protein which makes ketones as a byproduct
liver normally keeps ketones in check but excessive amounts leads to DKA
