Endocrine Flashcards
(56 cards)
1
Q
Preop assessment components?
A
- Dx of proposed procedure
- Medical Hx –Review of systems
- Current medications- herbs, minerals, PRn meds
- Allergies
- Physical exam
- Airway Exam
- Lab findings
- Surgical Hx – previous complications
- ASA status
- Consent
2
Q
What is the thyroid gland? Role?
A
Gland:
- Two lobes connected by an isthmus
- 4 parathyroid glands located posteriorly
- Superior larngeal nerve – external branch and RLN (recurrent laryngeal nerve) transverses the boarder
- Produces – T4 (thyroxine - prohormone) and T3 (triiodothyronine - active)
Role:
- Cell differentiation
- Organogenesis
- Thermogenesis
- Metabolic homeostasis
3
Q
What is the HPA axis for thyroid hormone release?
A
- Homeostasis disturbed, low T3/T4 detected at hypothalamus or low body temperature
- hypothalamus releases TRH
- Goes to anterior pituitary to release TSH
- TSH goes to thyroid gland to release T3/T4
- Normal homeostasis maintained with normal T3/T4 and normal body temp
4
Q
Difference between T3/T4?
A
T3
- Active
- 30 mcg/day
- 10% by gland (80% kidney/liver)- peripheral conversion in kidney and liver
- 3-4x’s as potent
- 1 day
T4
- Inactive
- 80 mcg/day- 2-3 x the amount of T3
- Solely by gland
- Potent
- 7 days- keep in mind people can still have s/s hyperthyroidism up to one week after surgery
5
Q
Causes of hyperthyroidism?
A
- Primary
- Graves disease (autoimmune disorder)- tricks receptor to thinking it’s TSH
- Toxic adenoma (gland overgrowth from lack of iodine)
- Multinodular goiter (genetics/lack of iodine)- Similar to toxic adenoms but can have genetic component too
- Secondary- something besides the thyroid causing excess T3/T4 to be made
- TSH secreting pituitary adenoma
- Tertiary
- Amiodarone toxicity
6
Q
S/S Hyperthyroidism?
A
- Neuro
- Anxiety & fatigue
- Ophthalmology
- Exophthalmos
- CV
- HTN, tachycardia, atrial fibrillation, & increased CO
- GI
- Diarrhea and weight loss
- Renal
- Hypercalciuria
- MS
- Muscle weakness
- Goiter
- Weight loss
7
Q
What with Free T4, free T3 and TSH be on labs for graves disease, multinodular goiter, and toxic nodules?
A
- Graves Free T4/T3 elevated, TSH down; TSH antibody present; RAIU diffuse uptake
- Mulinodular T4/T3 elevated, TSH down; RAIU areas of increased and decreased uptake
- Toxic nodule T4/T3 elevated; TSH down; RAIU focal uptake
8
Q
Potential treatment hyperthyroidism?
A
- Anti-thyroid drugs (Inhibits thyroid hormone synthesis)
- Methimazole or Propylthiouracil (PTU) – takes 6 -8 weeks
- Iodine inhibiting drugs (prevent hormone release)
- Potassium iodine
- Steroids (prevents conversion of T4 to T3/decrease secretion)
- Decadron 6 mg
- Hydrocortisone 100 mg
- Beta blockers (block adrenergic stimulation)
- Propranolol (prevents conversion of T4 to T3)
- Esmolol- blocks sympathetic, rapid on/off
9
Q
Anesthesia implications for hyperthyroidism
A
- most important goal is to make the patient euthyroid before surgery-can take 6-8 weeks
- Adequate depth of anesthesia to limit SNS activation
- Avoid medications that stimulate SNS
- Ketamine, pancuronium, ephedrine, or anticholinergics
- HR goal: < 85 bpm
-
Excellent airway exam
- X-ray or CT to evaluate airway compression
- Regional is excellent alternative (avoid adding epinephrine to solution)- avoid epi more theoretical risk with systemic absorption
- Eye protection
- Temperature monitoring – may need to cool
10
Q
S/S and differntial for thyroid storm?
A
Thyroid Storm
- Life-threatening emergency
- Response to stress
- Hyperpyrexia
- Tachycardia
- Myocardia ischemia
- Alterations in consciousness- difficult to see periop
Differential
- Light anesthesia
- Pheochromocytoma
- Neuroleptic malignant syndrome
- Malignant hyperthermia
11
Q
Treatment thyroid storm
A
- IV fluids
- Propylthiouracil via NGT
- Sodium iodide
- Hydrocortisone
- Propranolol/esmolol
- Cooling blanket
- Acetaminophen
- Meperidine
- Digoxin
12
Q
Primary and secondary causes for hypothyroidism?
A
Primary
- Hashimoto thyroiditis (autoimmune)
- Surgical removal of thyroid
- Severe iodine depletion
- Neck radiation
Secondary
- Pituitary disfunction
- Hypothalamic dysfunction
13
Q
s/s hypothyroidism?
A
- Neuro
- Fatigue, memory impairment, depression, or emotional liability
- CV
- Bradycardia, HTN w/ narrowed pulse pressure, or pericardial effusion
- Low voltage EKG
- Prolonged PR, QRS & QT interval
- Resp
- Need thyroid hormone for surfactant production
- Decreased response to hypoxia and hypercarbia
- Optho
- Blurred vision
- Renal
- SIADH – water retention
- Musculoskeletal
- Hyporeflexia
- Large tongue
- Cold intolerance
- Goiter
14
Q
Lab diagnosis of hypothyroidism?
A
- Primary hypothyroidism- TSH elevated, T4 low
- Subclinical TSH elevated; T4 normal
- Secondary TSH normal or low; T4 low
15
Q
Treatment for hypothyroidism?
A
- Hormone replacement with Synthroid
- Be careful with replacement – patient with CAD may not tolerate sudden increase in heart rate
16
Q
Anesthesia considerations with hypothyroidism?
A
- Little reason to postpone elective surgery with mild/moderate hypothyroidism
- Surgery should be postponed with severe hypothryoridism
- Maintain medications up to morning of surgery
- Cardiovascular changes are often the earliest changes
- Get EKG
- Cortisol deficiency is possible – atrophy of gland
- May need replacement therapy- need cortisol for stress response
- Maybe sensitive to sedatives
- Large tongue may lead to difficult airway
- Goiter may compress airway
17
Q
What is a myxedema coma? s/s?
A
- Extreme hypothyroidism
- Medical emergency
- 25 -50% mortality
- Coma
- Hypoventilation
- Hyponatremia (SIADH)
- CHF- incrase fluid retention can cause CHF
- Bradycardia
- Maybe precipitated by surgery, trauma, or infection
18
Q
Treatment myxedma coma?
A
- Tracheal intubation and controlled ventilation
- Levothyroxine 200 -300 mg IV- monitor HR, if CAD, don’t want to increase their HR too high
- Hydrocortisone 100 mg
- Keep warm
- Replace electrolytes as needed
19
Q
What is the parathyroid? Functions?
A
- 4 small endocrine glands located on the back of the thyroid gland
- Chief cells
- Produces parathyroid hormone
- Principal regulator of calcium and phosphate homeostasis
Functions:
- Increases osteoblast activity – increase calcium and phosphorous levels in circulation
- Increases renal tubular reabsorption of calcium
- Stimulates the synthesis of 1,25-dihydroxycholecalciferol (active Vit D)- causes intestine to absorb more Ca
- Increased phosphate excretion- if phophate lowered then Ca can increase because Ca binds to phosphate
20
Q
Role of calcium in body?
A
Regulating heart rate, muscle contraction, nerve impulse, strong bones & teeth, blood clotting, & regulating heart rate
- Total body calcium
- 99% in skeleton
- 1% in blood
- 45% bound to proteins like albumin and globulins- as albumin go down, calcium goes down. need to use albumin corrected Ca level
- 55% unbound ionized
- 45% ionized –ACTIVE form
- 10% complexed with bicarbonate, phosphate, or citrate
21
Q
What is the homeostasis of blood calcium level?
A
- Elevated calcium levels detected
- thyroid releases calcitonin
- calcitonin allows blood calcium levels to fall
- if calcium falls too low, parathyroid detects
- parathyroid releases PTH
- PTH allows blood calcium levels to rise
22
Q
Primary and secondary causes of hyperparathyroidism?
A
- Primary
- Parathyroid adenoma or hyperplasia
- Multiple endocrine neoplasm
- Secondary
- Vitamin D deficiency
- Kidney disease (decreased Vit D conversion)
- Intestinal malabsorption syndrome
23
Q
S/S Hyperparathyroidism?
A
- Neuro
- Mental status changes – delirium, psychosis, or coma
- CV
- Hypertension, ECG changes (prolonged PR, short QT & wide T waves), & arrhythmias
- GI
- N/V, constipation, & pancreatitis
- Renal
- Stones (r/t excess calcium), polyuria, polydipsia, impaired renal concentrating ability, & dehydration
- Musculoskeletal
- Muscle weakness and osteoporosis
24
Q
Diagnosis hyperparathyroidism?
A
- Total calcium: > 10.4 mg/dl
- Ionized calcium: > 1.5 mmol./L; >6 mg/dL
- Elevated PTH
- Increased 1,25 Vit D
- Decreased Phosphate
25
Hyperparathyroidism treatment?
* Mild **(10.4 – 11.5 mg/dl)**
* IV normal saline (dilution) & loop diuretics (reduce reabsorption)
* Moderate **(\> 11.5 mg/dl)**
* Continue normal saline & loop diuretics
* Bisphosphonates (inhibit osteoclasts)
* Calcitonin ( inhibits osteoclasts)
* Chloroquine (inhibits Vit D conversion)
* Mithramycin (Inhibits osteoclasts)
* Toxic side effects – thrombocytopenia, hepatic & renal toxicity, azotemia
* Severe
* Dialysis
26
Anesthesia management for hyperparathyroidism?
* Low threshold to get EKG
* No evidence that a specific anesthetic drug or technique has advantages over another
* Scheduled
* No special monitors usually required
* Emergency
* A-line (*frequent lab draws)*, central line, & Foley
* Unpredictable response to neuromuscular blockade
* May require decreased dosing & frequent monitoring
* Careful positioning- *osteoporosis*
27
Primary and secondary causes hypoparathyroidism?
* Primary
* Parathyroid surgery (removal for hyperparathyroidism)
* Accidental removal during thyroid surgery
* Secondary
* Suppression (severe hypomagnesemia, burns, or sepsis)
* Vitamin D deficiency
* Renal failure (hyperphosphatemia)
* Idiopathic hypoparathyroidism (congenital)
* Acquired hypoparathyroidism (autoimmune disease)
* Genetic (DiGeorge Syndrome)
* Heavy metal damage (copper)
28
S/S hypoparathyroidism?
* Neuro
* Anxiety, depression, or psychosis
* CV
* Hypotension, ECG changes (prolonged QT interval), CHF
* Resp
* Apnea or laryngeal spasms
* Neuromuscular
* Tetany
* Chvostek’s
* Trousseau’s
* Paresthesia
29
Diagnosis hypoparathyroidism?
* Total calcium: \< 8.5 mg/dl
* **_Ionized calcium : \< 4.0_**
* Increased phosphate
* Decreased PTH
* Decreased 1,25 Vitamin D
30
What is trousseau's sign?
* Induction of carpopedal spasm by inflation of sphygomomanometer above SBP for 3 min
* Response- carpopedal spasm characterized by:
* adduction of thumb
* flexion of metacarpopharlangeal joints
* extension of the interphalangeal joints
* flexion of wrist
31
What is chvostek's sign?
* Contraction of ipsilateral facial muscles elecited by tapping the facial nerve just anterior to the ear
* Reponse: twitching of the lip to spasm of all the facial muscles
32
Treatment of hypoparathyroidism? symptomatic v asymptomatic?
**Symptomatic**
* Intravenous Calcium
* Calcium gluconate 10 -20 mls of 10% solution (90 mg elemental calcium)- *preferred method of admin*
* Calcium chloride 10 ml’s of 10% solution (273 mg elemental calcium)- *caustic to veins if given peripherally*
* Intravenous magnesium
* Magnesium 2 -4 mg IV
**Asymptomatic**
* Oral calcium supplements
* Oral vitamin D supplements
33
Anesthesia management of hypoparathyroidism?
* Low threshold to get EKG
* No evidence that a specific anesthetic drug or technique has advantages over another
* Correct calcium and magnesium – have symptoms under control prior to anesthesia
* Judicious use of albumin or large amounts of blood products- *will bind Ca and decrease ionized calcium present*
* Avoid respiratory alkalosis – (decreases ionized calcium)
34
S/S hyperglycemia?
* Polydipsia
* Polyphagia
* Polyuria
* Weight loss
* Irritability
* Recurrent infections
* Visual changes
* Paresthesia
* Lethargy/fatigue
35
Diagnosis of diabetes?
* Hgb A1C \> 6.5%
* Fasting glucose \>126 mg/dL
* 2-hour glucose \> 200 mg/dL
36
Classifications of diabetes?
* Type I (5 -10%)
* T-cell mediated destruction of the beta cells
* Type II (80 – 90%)
* Deficiency in production or insensitivity in peripheral tissue or both
* Gestational (3-5% of pregnancies)
* Body becomes less sensitive to insulin
* Diabetes due to other causes (surgery, drug, or diseases)
* Stress response, steroids, or Cushing's/acromegaly
* *pre-diabetic in 3:1 ratio with normal diabetes. tons of prediabetics*
37
Type 1 vs type 2 diabetics?
Type I
* Requires exogenous insulin
* Usually normal/thin
* Autoimmune mediated
* Symptomatic
* FBS: 300 – 500 mg/dl
* Suppressible by insulin
* Unresponsive to oral medications
* Prone to ketoacidosis and hypoglycemia
Type II
* Non-insulin dependent
* Usually obese/sedentary
* Gland/receptor problem
* Maybe asymptomatic
* FBS: 150 -300 mg/dl
* High levels of glucagon
* Can be both responsive and resistant to insulin
* Responsive to oral hypoglycemics
* Prone to hyperglycemia hyperosmolar nonketotic acidosis
38
Onset, peak duration of rapid, short, intermediate and long acting insulins? SQ admin
* Rapid Acting (Lispro/Aspart)
* O: 15-30 M; P: 30 – 90 M; DOA 3-5 H
* Short (regular)
* O: 30 -60 M; P: 2 -5 H; DOA: 4 – 6 H
* Intermediate (NPH)
* O: 1 – 4 M; P: 4 -14 H; DOA: 10 -20 HR
* Long Acting (Glargine/Detemir)
* O: 1 -2 H; P: None; DOA: 24 hours
39
Drugs used to treat Type 2 DM?
* Acarbose (Precose)
* Alpha-glucosidase inhibitor
* Diarrhea
* Meglitinide (Repaglinide)
* Increase insulin release (ATP dependent K+ ATPase pump)
* Hypoglycemia
* Biguanide (Metformin)
* Decrease gluconeogenesis
* **N/V/D; Lactic acidosis (high doses – Hold 24 hours?)***- Some hospitals may not hold. lactic acidosis is theoretical risk and not seen commonly?*
* Sulfonylureas (Glyburide)
* Increase insulin release (ATP dependent K+ ATPase pump)
* Hypoglycemia and weight gain
* Thiazolidinediones (Rosiglitazone)
* PPAR receptor agonist (Increase fatty acid storage – decrease insulin resistance)
* Heart failure/Death
* Dipeptidyl Peptidase-4 inhibitors (Sitagliptin)
* Headache, leg swelling, ANGIOEDEMA
40
Goals of periop diabetes managmeent?
* Optimal perioperative glucose target is unclear
* Most information comes from ICU patients
* Most bodies recommend glycemic targets between 110-180 mg/dL
* American Diabetes Association – 80-180 mg/dL
* **Treatment threshold 180 mg/dl**
* Determining end organ complications
* Understand the patients medication regime
* Avoidance of hypoglycemia and hyperglycemia
* Especially severe \<40 mg/dL
* Try to make first case of day
41
End organ complications of diabetes?
* Atherosclerosis
* CAD, PVD, CVD, HTN, cardiomyopathy & silent MI
* Diabetic nephropathy (20 – 40%)
* Microalbuminuria, proteinuria, & elevated serum creatinine
* Chronic renal failure
* Neuropathies
* Stroke
* Polyneuropathy
* Autonomic neuropathy
* GI (gastroparesis)
* Musculoskeletal
* Stiff-joint syndrome
* Other
* Infections
42
What is autonomic dysfunction prevalence in diabetics? complications?
* Autonomic Dysfunction
* 20-40% of diabetics affected
* Affects CV and GI system most
Complications
* Intraoperative hypotension
* Increased vasopressor support
* Perioperative arrest
* Exaggerated response to intubation
* Intraoperative hypothermia
43
S/S Autonomic dysfunction?
* Ophthalmology
* Impaired adaption to light
* Sudomotor
* Dry skin
* Anhidrosis
* **CV (**green on ppt)
* **Tachycardia @ rest**
* **Exercise intolerance**
* **Orthostatic hypotension**
* **Silent MI**
* **Loss of beat to beat variability**
* GI
* Esophageal dysmotility
* Gastroparesis
* Constipation/diarrhea/incontinence
* GU
* Neurogenic bladder
* Erectile dysfunction
44
Preop tests for diabetics?
* CV
* EKG – others as need
* May display old infracts – Q waves, prolonged QT interval, or LV hypertrophy
* Resp
* Chest x-ray not usually required
* Labs
* A1C
* \> 9% is indicative of poor control
* Electrolytes
* US
* CBC
45
What is stiff joint syndrome in diabetics?
* 30 -40% of patients with IDDM have stiff joint
* Up to 30% can have difficult laryngoscopy
* (Reissell)
* Limited atlanto-occipital joint mobility
* Limited temporomandibular joint mobility
* Limited cervical spine mobility
* Positive prayers sign
* Palm print sign
46
Preop and introp managment of diabetics?
* Preop and intraoperative management
* Several methods of control
* Questions to ask yourself?
* How tight of control does the patient need
* Will the patient take oral hypoglycemics on the DOS
* Will the patient take insulin on the DOS
* How often will the blood glucose need to be monitored
* Will the patient require an insulin drip
* Will the patient require glucose IV solution
* How will the patient be managed in the postop period
47
Managmenet of type 1 DM insulin preop? PM night before and AM dose?
* Quick
* PM - Normal
* AM - Hold
* Regular
* PM – Normal
* AM - Hold
* Intermediate
* PM – 80%
* AM – 50 -80%
* Long
* PM – 80%
* AM – 50 -80%
* Pump
* AM – Basal rate
48
Managemet of type 2 meds around sx?
* Oral
* PM – Take
* AM – Hold – Restart as soon as possible
* Quick
* PM – Usual
* AM - Hold
* Regular
* PM – Usual
* AM – 1/2 to 2/3 normal dose
* Intermediate
* PM – 80%
* AM – 50 – 80%
* Long
* PM – 80%
* AM – 50 – 80%
49
S/S DKA? DX?
* Signs & Symptoms
* FSBS 300 -500 mg/dl
* Acute abdominal pain
* Lethargy
* Hypovolemia
* Diagnosis
* Ketone \> 7 mmol/L
* Bircarb \< 18 mEq/L
* pH \< 7.25
50
Treatment DKA?
* Restore intravascular volume
* Normal saline vs. 0.45% NS
* Start D5W @ FBS 250 - 300
* Insulin
* 10 – 20 IV unit bolus
* 1 -2 units/HR
* Electrolytes
* Potassium
51
Who is most likely to experience HHNC (hyperosmolar, hyperosmotic, non-ketotic coma)? S/S?
* Elderly with minimal DM
* Signs/symptoms
* FSBG \> 600 mg/dl
* Thirst
* Dry mouth
* Fever
* Increased urination
* Confusion
* Seizures
* Coma
52
Treatment HHNC?
* Restore intravascular volume
* Normal saline vs. 0.45% NS
* **_Start D5W @ FBS 250 - 300_**
* Insulin
* 10 – 20 IV unit bolus
* 1 -2 units/HR
* Electrolytes
* Potassium
* Goal
* Decrease 50 mg/dl /hour
* **Rapid correction may lead to cerebral edema**
53
What is hypoglycemia dx?
* Low blood glucose
* Blood glucose \< 50 -70 mg/dl
* Or signs and symptoms of hypoglycemia
* Difficult under anesthesia – need to have high index of suspicion
54
S/S hypoglycemia?
* Neuro
* Fatigue
* Anxiety
* Confusion
* Seizures
* LOC
* CV
* Tachycardia then to bradycardia
* Irregular rhythms
* Hypotension
* Resp
* Embarrassment- *rapid shallow breathing with inspiratory dyspnea......*
* Optho
* Blurred vision
55
Risk factors for hypoglycemia? What are situations where you could be unaware pt is hypoglycemic?
Risk factors
* Decreased oral intake
* Renal insufficiency
* Liver disease
* Infection
* Pregnancy
* Adrenal insufficiency
Unawareness
* Beta blockers
* Sedation
* Advanced age
* Long history of diabetes
* Diabetic neuropathy
56
Treatment hypoglycemia?
* Hospital:
* 25 – 50 ml’s D50
* 1 mg IM/IV glucagon
* D5 or 10 W
* Take quickly absorbed carbs such as
* half glass juice
* 5-7 jellybeans
* 3 tsp honey or sugar
* glucose that contains 15 g carb
* THEN follow up with slowly absorbed carb such as:
* sandwich
* biscuits
* glass of milk
* piece of fruit
* Retest after 15 min
* **_Goal: BG \> 100 mg/dl_**
