Endocrine Flashcards
ch 34, 35 5 questions
What pancreatic cells secrete glucagon?
Alpha cells
What pancreatic cells secrete insulin and amylin?
Beta cells
What pancreatic cells secrete pancreatic polypeptides (PP cells)?
Gamma cells
What substance do Delta cells secrete?
Somatostatin
What two types of hormones are secreted by the pancreas and what are their functions?
exocrine: aid in digestion (acini cells)
endocrine: in circulation, aid in metabolism (islets of Langerhans)
What 4 substances are secreted by Islets of Langerhans cells?
insulin (60% in beta)
glucagon (25% alpha)
somatostatin
pancreatic polypeptide
What venous structure are endocrine substances secreted into?
Hepatic portal vein
What is insulin and its half life?
insulin is an anabolic hormone that promotes energy storage, it is eliminated by the kidneys and has a rapid half time of about 5 mins
What is the MOA of insulin?
stores energy (glucose) by ^ gluc perm in skeletal m, liver, fat (mostly in skeletal m)
converts gluc to fat to ^ cellular amino acid, K, mg, P
encourages protein synthesis and energy for cellular metabolism
The secretion of insulin encourages the use of _____ for energy and slows the use of ____ and _____.
glucose, fats, amino acids
Why can’t skeletal muscle glycogen be reconverted into glucose?
skeletal muscle lacks the phosphate enzyme needed for this process
___% of glucose eaten in a meal is stored in the _____ as as _____.
60, liver, glycogen
What is the antagonist to insulin?
glucagon
What is the purpose of glucagon, its 1/2 life, and elimination?
Catabolic hormone that promotes energy release from adipose and the liver
3-6 min, elim liver & kidneys
What are the physiological effects of glucagon?
increases myocardial contractility (^cAMP), HR, AV conduction, relaxes biliary sphincter, increases glucose release
What stimulates glucagon secretion?
low BG, stress, sepsis, trauma, Beta agonists, acetylcholine
What inhibits glucagon secretion?
high BG, somatostatin, insulin, free fatty acids, alpha agonists
What is the difference between glucagon and glycogen?
glycogen: inactive, stored glucose
glucagon: hormone that encourages glycogen conversion to glucose (active)
______ causes hypoglycemia because it ______ glucagon secretion
phenylephrine (alpha agonists), inhibits
______ causes hyperglycemia because it ______ glucagon secretion
dobutamine (beta agonists), stimulates
What are some indications for admin of glucagon?
low blood glucose, relax biliary sphincter during ERCP, ^CO postMI, treat BB OD
What is the function of Somatostatin?
regulates/ibihits illiet cell secretion, manages gastric motility, and splenic/GI blood flow.
What is the function of Pancreatic Polypeptides?
inhibits pancreatic exosecretion
What indicates whether an individual has type 1 or 2 diabetes: age or physiology?
underlying physiology
DM1: autoimmune destruction of beta cells, virus genetics, beta destruction
DM2: lack of insulin secretion OR insulin resistance
What is the TX for T1DM and the major complication?
T: insulin
DKA: ^ anion gap, ^ glucose, kussmaul’s, excess ketones
What is the treatment for DKA?
volume resuscitation, insulin, and K replacement after acidosis is corrected (HCO3)
In T2DM, what are the levels of insulin and glucagon?
I: normal to high
G: high/resistant to suppression
What is treatment of T2DM, lab dx, and the complication?
T: weight reduction, dietary changes, oral agents, and/or insulin
L: fastinggluc: >126 randgluc >200
C: Hyperglycemic hyperosmolar state: BS>600
tx: same as DKA
What is the goal of insulin therapy?
<7% A1c, 70-130 premeal glucose, post meal <180 (varies)
What type of insulin is most commonly given in surgery?
short acting insulin
Why are long acting insulins most commonly not given during surgery?
they are a long duration of action and it takes a long time for them to be effective
What insulins are rapid acting? what are their peak, duration, and max actions
lispro (humalog), aspart (novolog), glulisine (apidra)
start of action: 15-30 min
peak: 1-2hr
duration: 3-6hr, max 4-6hr
What is the one and only short-acting insulin? when does it start, peak, and duration of action?
regular insulin
starts: 30min-1hr
peaks: 2-4hr
duration: 3-6hr, max: 6-8
What is the one and only intermediate-acting insulin and its (start, peak, and duration) of effects?
NPH: Neutral Protamine Hagedorn insulin
start: 2-4hr
peak: 8-10hr
duration: 10-18hr max: 14-20hr
Use of what type of insulin can cause increase the risks of protamine reaction?
NPH: Neutral Protamine Hagedorn insulin
What are the two long-acting insulins and their (start, peak, and duration) of effects?
Glargine (Lantus) and detemir (Levemir)
start: 1-2hr
peak: 0
duration: 19-20/24 (L:24, G:20)
What is the half life and elimination of iv insulin?
5-10 min via proteolytic enzyme
What patient metabolizes insulin better: renal or liver failure?
patient with renal failure due to 50% of insulin being metabolized in the liver via first pass
What type of insulin acts most similarly to endogenous insulin?
lispro
What is the ONLY type of insulin that can be given IV?
regular insulin (humulin R)
What is the ultra long acting insulin?
Degludec
What are side effects and drug interactions of insulin?
low BG, allergic reaction, lipodystrophy (site), insulin resistance
interactions: protamine
drugs that counter (epi, glucagon, estrogen), extend, or enhance hypoglycemic effects (MAOIs, tetracyclines, and subcyliates)
What is the indication, moa, and side effects of metformin?
T2DM, PCOS, NFLD
activates adenosine monophos via protein kinase which decreases gluconeogenesis+lysis; deactivates livers ability to activate glucose, also decreases gi glucose absorption
SE: lactic acidosis, AKI, gi intol, liver disease, weight loss, b12 def
What is a major pro and a major con of metformin?
P: does not cause hypoglycemia
C: must be d/ced 48 hours prior to surgery due to interaction with contract dye
What is the indication, moa, and side effects of surlfonylurea?
manages glucose in patients with some Beta cell function
increases release of insulin in beta cells via ATP
SE: hypoglycemia (esp w glyburide)
What is a contraindication of sulfonylurea therapy?
sulfa allergy
What should sulfonylurea be discontinued prior to surgery?
24-48 hours prior
What is a secondary effect of the antihyperglycemic agent, glipizide?
mild diuretic
What drugs work similarly to sulfonylureas by stimulating insulin secretion from beta cells?
Meglitinides: Repaglinide & Nateglinide
What drug class is useful in post meal hyperglycemia?
α-Glucosidase Inhibitors: acarbase and miglitol
What are thiazolidinediones moa and contraindications?
decrease insulin resistance work in 4-12 weeks, increases weight gain from fluid, cannot be used in liver failure
What antihyperglycemic agent causes delayed gastric emptying?
Glucagon-Like Peptide-1 Receptor Agonists: Exenatide & Liraglutide and Pramlinitide
How do Dipeptidyl-Peptidase-4 Inhibitors (end in liptin) work and what is a consideration?
increase insulin release from pancreas. decrease dose in patients with renal failure
When should antihyperglycemic agents be stopped prior to surgery?
48hr prior
What type of insulin is used in insulin pumps?
rapid acting
What complications can occur with periop insulin pump use?
cath occlusion, hypoglycemia, cath dislodgement
How should a insulin pump be managed?
check BG preop, Q1H, and post op. continue basal rate and give boluses accordingly via pump
What hormones are secreted by the hypothalamus?
luteinizing hormone-decreasing hormone
corticotropin-releasing hormone
thryotropin-releasing hormone
prolactin inhibiting and releasing factors
Where is the pituitary gland located and what is it connected to?
lies in the sella turcica at the base of the brain and is connected to the hypothalamus by the pituitary stalk.
What hormones are secreted from the anterior and posterior pituitary gland?
A: FSH, luteinizing hormone, ACTH, TSH, Prolactin, Growth hormone
P: ADH (arginine vasopressin), oxytocin
what does growth hormone (somatotropin) do?
stimulates linear bone growth, anabolic effects, ketogenic, and diabetogenic
What occurs due to excessive growth hormone secretion?
acromegaly, most commonly caused by pituitary adenoma, causes gigantism if prior to puberty
What are anesthesia considerations for patients with acromegaly?
distorted facial feature (difficult to mask), large tongue, teeth, and epiglottis (difficult laryngoscopy), subglottic narrowing and vocal cord enlargement (use smaller tube: difficult ETT placement, turbinate enlargement (risk of epistaxis: avoid nasal intubation), OSA is common, entrapment neuropathies are common, skeletal muscle weakness
What is the primary building block for steroids?
cholesterol
What anesthesia drugs stimulate and inhibit the secretion of prolactin?
Stimulates: metoclopramide, cimetidine, opioids, methyldopa
Inhibits: prolactin, dopamine, l-dopa
What drugs stimulate adrenocorticotropic secretion?
alpha agonists and beta antagonists
What drugs inhibit adrenocorticotropic secretion?
opioids and etomidate
What does TSH do?
accelerates formation of thyroid hormones that manage metabolism
stimulates respiration rate, tremors, and decreases sleep time
Where are the 3 vasopressin receptors?
1: vascular smooth muscle
2: collecting duct of kidney
3. fat
What is SIADH, what causes it, treatment?
excess ADH, low na, low urine na, hypertonic urine
TBI, SAH, cancer, carbamazepine
tx: fluid restrict, hypertonic nacl
What is DI, what causes it, treatment?
deficit in ADH, caused by pituitary surgery, polyuria, low urine osmolarity
tx: DDAVP, vaso, ACE/ARB
dose: vaso- po: 0.3-0.6mg.day, iv: 1-4mcg/day, nasal: 5-40mcg/day
What 3 things does the thyroid secrete?
T3
T4
Calcitonin
What do thyroid hormones do?
controls protein synthesis by activating DNA transcription during cell proliferation, convert alpha receptors to beta receptors, cardiac cholinergic receptors are decreased by thyroid hormones. stimulates iodide pump, iodine and a substrate
What 6 things can cause hyperthyroidism?
Grave’s Disease (autoimmune), most common, Myasthenia gravis (autoimmune), Multinodular goiter, Pituitary Adenoma, Carcinoma, Pregnancy
What lab findings indicate hyper and hypo thyroidism?
hyper: low TSH, high t3, t4
hypo: high TSH, low t3, t4
What are s/s of hyperthyroidism?
weight loss, exophthalmos, high ca2+, htn, tachyarrythmias, afib, high MV
What drugs treat thyroid storm?
Thionamides (Methimazole,
Propylthiouracil, Carbimazole), PTU, potassium iodide, radioactive iodide, propranolol, esmolol, glucocorticoids
What are the 4 B’s of thyroid storm management?
block synthesis
block release
block t4 to t3 conversion ptu
beta blocker
What can thyroid storm mimic?
MH, pheochromocytoma, NMS, light anesthesia
How long does it take PTU to achieve euthyroid state?
6-7 weeks
What drug is contraindicated to treat fever in patients experiencing thyroid storm?
aspirin (dislodge t4 from plasma proteins)
What is an airway concern associated with iodine solutions?
angioedema and laryngeal edema
What are the causes and findings associated with hypothyroidism?
hashimoto’s thyroiditis, iodine def, pituitary dysfntn, neck radiation, thyroidectomy
weight gain, fatigue, lethargy, delayed gastric emptying, large tongue
What are indications for synthetic thyroxine T3 (liothyronine)
thyroid cancer, + surgery and radioiodine, dx to differentiate from thyroid issue, myxedema coma
What are indications for synthetic thyroxine T4 (levothyroxine)
primary hypothyroidism
decreased dose in older adults and increased in pregnancy
T4 has a half-life of 7 to 10 days, hypothyroid patients can miss several days of T4 without consequences.
Tx or suppression of euthyroid goiters, thyrotropin-dependent thyroid cancer
What should occur if a patient presents in myxedema?
cancel surgery because:
delayed gastric emptying increases aspiration risk, causes hypodynamic circulation, increased sensitivity to NMB
What complications are associated with thyroidectomy?
hypothyroid, hemorrhage, tracheal compression, recurrent laryngeal nerve injury, and hypocalcemia
How should emergent surgery in a patient with hyperthyroidism be managed?
beta-blocker potassium iodide glucocorticoid, and PTU
What drugs should be avoided in patients with hyperthyroid?
sympathomimetics, anticholinergics, ketamine, and pancuronium
What do thioamides and beta blockers do in hyperthyroid management?
prevent t4 to t3 conversion
When should potassium iodine be given prior to surgery and what does it do?
10 days prior, reduces synthesis and release of thyroid hormones
What is the therapy of choice for Grave’s disease?
radioactive iodine
How long should euthyroid be maintained prior to an elective surgery?
At least 6-8 weeks
What 5 types of hormones are secreted by the adrenal gland?
androgens
mineralocorticoids
glucocorticoids
catecholamines
peptides
What is Conn’s syndrome and treatment?
high aldosterone
primary: caused by increased aldosterone release, secondary: extrarenal cause
HTN, low K, metabolic acidosis
tx: spironolactone and ACE inhibitors
What are anesthesia considerations for Conn’s syndrome?
sensitive to NMB, dont hypervent or give excess fluids (can cause pulm edema)
What are the effects of cortisol?
increases gluconeogenesis, breaks down protein, mobilizes fatty acids, anti-inflammatory
What is cushing’s syndrome?
excessive cortisol, pituitary adenoma, ACTH syndrome, or endogenous steroids
What is addison’s disease?
low cortisol, autoimmune, HIV or TB
treatment cortisol replacement therapy, fluid replacement D5ns
What are the dosages of steroid replacement for addison’s disease?
acute insuff: 15-30mg cortisol
crisis: hydrocortisone 100mg + 100-200mg/24hr
++ dexamethasone for anti inflammatory and analgesia effects
What are the two types of corticosteroids?
mineral: evoke distal renal tubular reabsorption of Na in exchange for K ions
gluco: anti inflammatory (T&Bcells effects)
Where are mineralocorticoid receptors?
renal distal tubules, colon, salivary glands, hippocampus
Which type of steroid suppresses the HPA axis?
systemic glucocorticoids (due to having both systemic and local immunosuppressant effects)
How do steroids decrease inflammation?
target 11-BHSD which prevents cortisol and cortisone activation
What is the difference between permissive and protection steroid concentrations?
Permissive: low basal rate, allows the body room to react to stressors
Protective: high levels causing anti-inflammatory and immunosuppressive effects
What are the derivatives of synthetic cortisol?
dexamethasone, prednisolone, prednisone, methylprednisolone, betamethasone, triamcinolone, and hydrocortisone
What OTC medication interferes with the absorption of corticosteroids?
oral antacids
How are the synthetic corticosteroids dosed?
based on their equivalence to 20mg of cortisol
dexamethasone and betamethasone are most efficacious
What are in indications for synthetic corticosteroids?
anti-inflammatory, immunosuppression, allergies, asthma, cancer, antiemetic, analgesia, cerebral edema, cardiac arrest
What corticosteroid produces the strongest glucocorticoid effects?
methylprednisolone
Why is dexamethasone better than betamethasone?
B does not have mineralocorticoid effects of cortisol.
D used in cerebral edema, PONV, and inflammation
What is a common indication for triamcinolone?
epidural injections for lumbar disc disease. initially causes mild diuresis
SE: skeletal muscle weakness anorexia, sedation
What are the 2 choice steroids for anti-inflammation? + consideration
prednisolone and prednisone
technically palliative as the underlying cause remains- masks s/s/delaying diagnosis and treatment
What are two indications specifically for dexamethasone?
analgesia and cardiac arrest
What is the dosage for chronic adrenal insufficiency?
25-37.5mg cortisone po
mineralocorticoid (fludrocortisone): 0.1-0.3mg
What are the effects of topical steroids in the setting of an allergic reaction?
decrease cytokines, chemokines, and immune cell recruitment. induces cutaneous vasoconstriction
What are the inhaled corticosteroids and how are they absorbed?
beclomethasone, budesonide, fluticasone, ciclesonide, and triamcinolone. absorbed in oropharyngeal tissues and swallowed
for treatment of asthma, inhaled glucocorticoids should be used in conjunction with:
first line beta2 agonist therapy
What are the indications and dose of iv corticosteroids to treat asthma?
active reactive airway disease, bronchospasm. 1-2mg/kg of cortisol equivalent which is 4-8mg of dexamethasone
When should inhaled corticosteroids for asthma be given prior to surgery?
1-2hrs prior to induction
corticosteroids enhance the effects of ______ agonists.
Beta, 4-6 hrs, decreases risk of bronchospasm
What corticosteroid is first line for antiemetic effects?
dexamethasone. prevents PONV only when administered near the beginning of surgery
was used in conjunction with TIVA as first-line and second-line methods of prophylaxis against PONV, also effective in suppressing chemo induced NV
What is the PONV steroid dose?
4-6mg or 8–10mg (has ceiling dose), lasts up to 24hr
When should glucocorticoids be given to exhibit analgesic effects? what is the MOA?
preop to 30mins prior to induction. inhibit phospholipase enzyme for the inflammatory chain reaction along with the cyclooxygenase and lipoxygenase pathways
When are corticosteroids given for immunosuppression r/t to transplant?
high dose at surgery, eventually taper to small maintenance dose
dose should be increased in the setting of rejection
What steroid and dose should be given to treat post intubation laryngeal edema?
0.1-0.2mg/kg iv dexamethasone (4-6mg)
0.6mg/kg po for peds with croup
When should corticosteroids be given to mom prior to delivering if 24-36 weeks to prevent respiratory distress syndrome?
at least 24 hours prior
T/F dexamethasone should be given for prolonged periods for low-birth weight babies
True- reduces risks of bronchopulmonary dysplasia
How do steroids assist recovery in cardiac arrest?
CA is associated w/ lower cortisol levels, vasoplegia, and myocardial dysfunction
this enhances cardiac function
Why do patients on chronic steroids receive steroids prior to surgery?
due to the suppression of the HPA axis, pt cannot release increased cortisol in response to operative stress
What steroid dose indicates suppression of the HPA axis?
prednisone >20mg for >3 weeks + stress dose
prednisone 5-20mg/day > 3 weeks
dexamethasone is sometimes used for stress dosing
What 3 steroids do not have mineralocorticoid effects?
dexamethasone, betamethasone, and triamcinolone
What are the doses of intraop stress doses of steroids?
minor surgery (carpel tunnel) no replacement
minor stress (hernia repair): 25 mg hydrocortisone or 5 mg methylprednisolone
mod stress (open belly, joint replacement): 50-75 mg/day hydrocortisone x 1-2 days
major stress: 100-150 mg hydrocortisone/day x 2-3 days
What are the side effects of chronic steroid use?
suppression of HPA axis, electrolyte/metabolic changes, osteoporosis, PUD, skeletal m myopathy, central nervous system dysfunc, peripheral blood changes, inhibits norm growth
use of chronic steroids causes increased clearance of what two drug types?
anticoagulants (increases clot risk) and salicylates
What are metabolic changes related to steroid use?
lowk, metabolic alk, edema, weight gain, inhibits glucose use in tissues> leading to high BG (manage w/ diet, insulin +or both), thin skin, osteo
How/what are the CNS effects of steroids?
psychosis, mania, depression (increases with high dose), suicidal tendencies
What is an ophthalmic SE of chronic steroid use?
cataracts
What 3 things regulate calcium?
parathyroid hormone, calcitonin, and vitamin D
What is the treatment for hypercalcemia?
IVF, bisphosphonates, calcitonin, and glucocorticoids (decreases vit D)
What are two SE of bisphosphonates?
Renal injury and jaw osteonecrosis
What are the causes, s/s, and management of hypocalcemia?
rhabdo, pancreatitis, sepsis, burns, fat embolism, recent MTP, hypoalbuminemia, hypomagnesemia, thyroidectomy/neck surgery, or renal insufficiency
s/s: CHF, low BP, arrhythmias, and nm irritability
IV calcium
Where is octreotide secreted and how does it work?
anterior pituitary, inhibits release of growth hormone, increases development of gallstones
What are the clinical uses of of vasopressin?
AVP sens. DI, refract. low BP (esp w/ ACE/ARB use), hem. varices, sepsis, cardiac arrest
What should be given to low BP r/t anaphylaxis OR severe catecholamine deplet. 2/2 resect. of pheocytcromtoma?
vasopressin
what are the 3 causes of hypotension during sepsis and tx?
excessive nitric oxide, +++ renin/ang system, and low lvls of vasopressin
tx: vaso @ 0.01-0.04u/min
___ units of vaso has similar effects to ____ mg of epi in the setting of ventricular fibrillation and PEA
40, 1
What is more effective in treating asystole: epinephrine or vasopressin?
vasopressin
What is the dose of vasopressin for management of bleeding esophageal varices?
20u/5min: decreases hepatic blood flow due to splanchnic vasoconstriction
-can also give vaso directly into superior mesenteric artery
What are the side effects associated with vasopressin?
vasoconstrictive complications, facial pallor, baroreceptor reflex (if major ^^^ in BP), CA constriction (angina), increased peristalsis, low plts
How does oxytocin work and what is the dosage?
prevents uterine atony which decreases hemorrhage, 1-3u/30sec. can cause hypotension
What pressor may be needed if giving large amounts of oxytocin?
phenylephrine
How does previous exposure to oxytocin effect efficiency?
causes downre/desens which results in higher risk of PPH r/t uterine atony
When should synthroid be d/ced prior to surgery?
take the morning of, do not d/c
What are the effects of hyperthyroidism on pt response to meds (esp vasopressin)
increased response
Treatment of hyperthyroidism can cause:
hypothyroidism
What are the effects of thyroid alterations on MAC?
nothing:) same as normal doses
What sympathomimetic should not be used in patients with hypothyroidism?
phenylephrine
How does steroid administration play a role in multimodal anesthetic management?
by decreasing inflammation to site
T/F dexamethasone should be given postop to treat PONV
False, has no effect if given post operatively
What are some anesthesia considerations for the effects of dexamethasone
causes perineal itching (give after induction), decreases need for inhaled anesthetics
endogenous cortisol and synthetic corticosteroids are examples of ________, while aldosterone is an example of a _______.
glucocorticoids, mineralocorticoid- goal: balance na/h2o balance
What is the ONLY type of insulin that can be given both IV and SUBQ?
regular insulin
What 3 drugs counter the hypoglycemic effect of insulin and what 3 drugs extend/enhance the effects?
counter: epi, glucagon, and estrogen
E/E: MAOIs, salicylates, and tetracyclines
What is the most common cardiovascular side effect related to the use of radioactive iodine?
bradycardia
what are the effects of sympathomimetics on thyroid hormones?
greater sensitivity of beta receptors to release T3 and T4 which is why these medications are contraindicated in thyroid storm
due to over responsiveness (HTN)
What is the treatments for acute adrenal crisis?
100mg hydrocortisone + 100-200mg every 24H
(same tx for HPA supp)
Why shouldnt life threatening allergic reactions be treated with corticosteroids?
because the anti inflammatory effect has a delayed onset
How long after after surgery (thyroidectomy,parathy,neck) do patients experience symptomatic hypocalcemia?
within 12-24 hours
What is the dose of oxytocin after giving birth?
10-20u/1000mL
opinion r/t corticosteroid use in anesthesia:
must be aware of both chronic and acute use and proper dosing. MOA r/t surgical stress, anti inflammation, immunosuppression, and analgesia. blood sugar effects.
long term therapy is bad and should be last resort
