How are most hormones regulated? Positive or negative feedback loop?
Negative feedback loop
The interactions within the endocrine system constitute the ____________ a major part of the neuroendocrine system that controls reactions to stress and regulates many body processes.
The endocrine system helps regulate: (7)
Chemical composition and volume of interstitial fluid
Metabolism and energy balance
Biological clock or circadian rhythms
Contraction of smooth and cardiac muscle fibers
Some immune system activities
Operations of reproductive system
Does the endocrine system control growth and development?
Thyroid Feedback Loop
The thyroid senses low levels of thyroid hormones ___ and ___ which then responds by releasing what hormone?
T3 and T4
thyrotropin-releasing hormone (TRH)
The TRH (thyroid-releasing hormone) stimulates the pituitary to produce what?
thyroid-stimulating hormone (TSH)
What hormone is released from the hypothalamus?
TRH (thyroid releasing hormone)
What hormone is released from the anterior pituitary gland?
________ stimulates the thyroid gland to secrete the hormone thyroxine (T4) (inactive form) which is converted to triiodothyronine (T3), which is the active hormone that stimulates metabolism.
________ is also produced by the hypothalamus, and has an opposite effect on the pituitary production of TSH, decreasing or inhibiting its release.
The concentration of thyroid hormones (T3 and T4) in the blood regulates the pituitary release of TSH. True or false?
When T3 and T4 concentrations are low, the production of TSH is ______ and vice-versa.
Note: This is known as a negative feedback loop.
T4 and T3 (controlled by TSH) levels peak in the early morning. True or false?
Diurnal peaks in late evening.
What factors influence secreted amounts of T3 and T4? (6)
Gonadal- and adrenal cortical-increased steroids (increase)
Exposure to cold (increase)
Chemicals (dopamine, catecholamines)
What are the functions of T3 and T4? (9)
Regulate protein, fat, and carbohydrate catabolism in cells
Regulates metabolic rate and body heat production
Maintains growth hormone secretion, skeletal maturation
Affects CNS development
Maintains cardiac rate, force, and output
Affects respiratory rate and oxygen utilization
Affects RBC production
Enhances cholesterol excretion in the bile
What type of thyroid condition results in a goiter?
What type of thyroid condition results in exophthalmos?
What are the symptoms of hyperthyroidism? (10)
Nervousness or anxiety
Fatigue and weakness
Weight loss or gain
Hyperdefication or loose stools
What are the signs and symptoms of hyperthyroidism? (5)
Thyroid enlargement (goiter)
Hyperkinesis (state of overactive restlessness)
Eye signs (exophthalmos)
For hyperthyroidism, we would expect the following increase/decrease in labs:
_________ T3 and T4
________ free thyroxine or T4
elevated T3 and T4
elevated free thyroxine or T4
What other labs could you expect for a pt with hyperthyroidism? (5)
Increased alkaline phosphatase
Increased erythrocyte sedimentation rate
What is the treatment for hyperthyroidism? (4)
What are preoperative considerations for pts with hyperthyroidism? (2)
Airway exam is important, especially if a goiter is present.
Ptoptosis will require diligent eye protection.
In an emergency surgery situation, what drugs will we need to have available for a pt with hyperthyroidism? (4)
What are the symptoms of hypothyroidism? (10)
Arthalgias, myalgias, muscle stiffness and cramps
What are the signs of hypothyroidism? (5)
Weight gain (or loss)
Cardiac rub or soft heart tones causes by pericardial effusion
For hypothyroidism, we would expect the following increase/decrease in labs:
_____ Free T4
________ TSH in primary hypothyroidism
_______ or normal TSH in pituitary insufficiency
Decreased free T4
Decreased or normal TSH
What other labs could you expect for a pt with hypothyroidism? (4)
Increased serum cholesterol, liver enzymes, creatine
What is a major complication of severe hypothyroidism?
What are the complications of myxedema coma? (5)
What factors may induce myxedema coma? (4)
infection, cardiac or respiratory
Elderly men are more at risk for myxedema coma. True or false?
How is hypothyroidism treated? (2)
Thyroid hormone replacement--synthetic levothyroxine
Treatment monitored closely with lab values and titrated.
What hormone raises serum Ca++ levels while promoting bone reabsorption?
The following would increase/decrease for pts with hyperparathyroidism:
_______ parathyroid hormone
_______ calcium levels
What are the consequences of hypercalcemia? (7)
What is the most common cause of hyperparathyroidism?
Is parathyroid cancer common?
What are the signs of hypocalcemia? (8)
tingling of lips and hands
muscle and abdominal cramps
positive Chvostek’s and Trousseau’s signs
defective nails and teeth
What condition may common be seen after thyroidectomy, but may only be transient?
What is the treatment for hypoparathyroidism? (4)
IV calcium gluconate
What are the tests for hypocalcemia? (2)
What labs are ordered for parathyroid issues? (6)
What is the most common endocrine disease?
What are long-term complications of diabetes mellitus?(4)
What are the major risks for those with diabetes? (5)
What type of diabetes?
NO insulin production – thought to be an autoimmune destruction of islet cells in pancreas
Note: They become dependent on exogenous insulin.
What type of diabetes?
Relative deficiency in insulin – insulin resistance
Associated findings include – obesity, abnormal insulin levels, strong genetic component
What type of diabetes?
Complicates about 4% of pregnancies
Glucose intolerance that is identified during pregnancy
What are the treatments for DM? (4)
Oral hypoglycemic drugs
What are anesthetic considerations for DM pts? (4)
Autonomic lability (Temp, BP, HR dysfunction)
Silent ischemia or CAD
Inhibited motility of GI
Glucose control--may affect healing
Perform a pregnancy test for any female of childbearing age which is ____-____ YO.
What are 2 major types of pregnancy test?
How accurate are home urine pregnancy tests?
What blood pregnancy test measures the exact amount of hCG in the blood?
quantitative blood test
What blood test gives a simple yes or no answer to whether one is pregnant or not?
qualitative blood test
When are hCG levels at their peak from time of inception?
Surgery is only conducted during pregnancy when it is absolutely necessary for the wellbeing of the mother, fetus, or both. True or false?
All general anesthetic drugs cross the placenta. True or false?
Regional anesthesia is usually preferred in pregnancy when it is practical for the medical and surgical condition. True or false?
What are the most common surgeries for pregnant patients not related to the pregnancy? (3)
surgery for maternal malignancy
Surgery should be done at an institution with neonatal and pediatric services. True or false?
An obstetric care provider with cesarean delivery privileges should be readily available. True or false.
A qualified individual should be readily available to interpret the fetal heart rate patterns. True or false?
What are the cardiovascular changes that occur during pregnancy? (5)
increased blood volume
decreased peripheral resistance
decreased blood pressure
What are the pulmonary changes that occur during pregnancy? (4)
increased tidal volume
What are risks presented by a pregnant patient intra-op? (4)
difficult intubation due to swelling
hyptension due to aortocaval compression
If the fetus is considered pre-viable, it is sufficient to ascertain the fetal heart rate by Doppler before and after the procedure. True or false?
Intraoperative electronic fetal monitoring may be appropriate when all of the following apply: (5)
The fetus is viable.
It is physically possible to perform intraoperative electronic fetal monitoring.
A health care provider with obstetric surgery privileges is available and willing to intervene during the surgical procedure for fetal indications.
When possible, the woman has given informed consent to emergency cesarean delivery.
The nature of the planned surgery will allow the safe interruption or alteration of the procedure to provide access to perform emergency delivery.