Autoimmune Disorders (Test 2)

Question 1

Occurs when immune system reacts against self-antigens and a person’s own tissues are damaged by antibodies or autoreactive T cells.

Answer 1

autoimmunity

Question 2

What is the most common chronic inflammatory arthritis?

Answer 2

rheumatoid

Question 3

Does RA have a higher incidence in men or women?

Answer 3

2-3 x higher in women

Question 4

What are the causes of pericardial effusion?

Answer 4

can occur from almost any pericardial disease such as infection, trauma, metastatic disease, mediastinal disease, radiation, rheumatoid arthritis, systemic lupus erythematosus, and scleroderma

Question 5

What is the underlying pathology in the joints of patients with RA?

Answer 5

cellular hyperplasia occurs in the synovium with progressive infiltration by lymphocytes, plasma cells, and fibroblasts–> the articular cartilage is eventually completely destroyed

Question 6

What symptoms characterize RA?

Answer 6

symmetric polyarthropathy (involves 5 or more joints simultaneously; is usually caused by autoimmune) ->affects weight bearing joints, proximal interphalangeal and metacarpophalangeal joints; worse in a.m.; in severe case all joints may be affected except lumbar and thoracic spine; weight loss, morning stiffness, and fatigue; insidious onset

Question 7

What are treatment options for RA?

Answer 7

palliative; corticosteroids suppress inflammatory symptoms of RA; anticytokine agents (etanercept, adlimumab, and infliximab) interfere with cytokine known as tumor necrosis factor–> slowing progression of disease; methotrexate (1st line therapy–>inhibits metabolism of folic acid–> nausea, alopecia, h/a, skin pigmentation is common) is effective in reducing symptoms, as are immunosuppressive drugs such as cyclophosphamide & cyclosporine

methotrexate use: For the treatment of rheumatoid arthritis, inhibition of DHFR is not thought to be the main mechanism, but rather the inhibition of enzymes involved in purine metabolism, leading to accumulation of adenosine, or the inhibition of T cell activation and suppression of intercellular adhesion molecule expression by T cells.[21] In these cases, patients should supplement their diets with folate.

Question 8

What are some major anesthetic considerations for patients with RA?

Answer 8

careful airway evaluation d\t arthritic changes in laryngeal, temporomandibular, and cervical joints; chronic NSAID use may inhibit platelet function & lead to liver or kidney dysfunction; use of cyclophosphamide (immunosuppressive) can inhibit plasma cholinesterase and prolong DOA of Sux; use of long-term corticosteroid therapy will warrant extra steroid coverage

Question 9

What is the most common hematologic abnormality in RA?

Answer 9

anemia

Question 10

What is the most common pulmonary complication of RA?

Answer 10

pleural effusion (excess of fluid between pleural layers–> impairing breathing and limiting expansion)

Question 11

What are some cardiac complications that may be present with RA?

Answer 11

1/3 patients exhibit pericardial thickening with effusion; pericarditis, myocarditis, and coronary artery arteritis may be present; aortitis may produce dilation of aortic root and subsequent aortic regurgitation…. rheumatoid nodules may also disrupt cardiac conduction system

Question 12

What are the airway management concerns with RA?

Answer 12

may affect TMJ and restrict mouth opening; may affect joints of the larynx and cause generalized edema and laryngeal swelling; cervical spine instability and atlantoaxial subluxation can push odontoid process into foramen magnum during laryngoscopy

Question 13

What is the difference b\w osteoarthritis and RA?

Answer 13

RA is characterized by immune-mediated joint destruction with chronic and progressive inflammation of synovial membranes; as opposed to being caused by articular wear and tear of osteoarthritis, which is a degenerative disease affecting the articular surface of one or more joints

Question 14

________ is a systemic disease affecting one or more organ systems.

Answer 14

RA

Question 15

Why does RA typically cause deformity in patients?

Answer 15

b\c it often affects small joints of hands, wrists, & feet causing severe deformity–> leads to difficulty placing radial artery cannula or intravenous access

Question 16

If a patient with history of RA is taking steroids, immune therapy, or methotrexate…. what is an important diagnostic test to consider prior to surgery?

Answer 16

flexion and extension radiographs of cervical spine; if atlantoaxial (C1-C2) instability is present intubation should be done with inline stabilization and fiberoptics

Question 17

What is the importance of assessing mouth opening in a patient with RA?

Answer 17

if TMJ involvement is found, patient may have limited jaw mobility and ROM

Question 18

What are some concerns with the use of NSAIDs by patients with RA?

Answer 18

GI bleeding, renal toxicity, platelet dysfunction

Question 19

What is an endocrine concern for patients with RA?

Answer 19

adrenal insufficiency and impaired immune system (from glucocorticoid therapy)

Question 20

According to slides from class, what are some of the etiologic causes of RA?

Answer 20

exact cause unkown; impaired immunity, stress, & environmental factors may have role; viral or bacterial infection altering the immune system in genetically susceptible host may play a role (autoimmune response, molecular mimicry); circulating autoantibodies called rheumatoid factors are detectable in 70-80% of patients with RA

Question 21

What are the most common sites for RA manifestations in the joints?

Answer 21

hands, wrist, feet

Question 22

Joint involvement in RA progresses in 3 main stages. Explain.

Answer 22

1) inflammation of joint synovial membrane and infiltration by leukocytes; 2) rapid division and growth of cells in joints; 3) liberation of osteolytic enzymes, proteases (any enzyme responsible for proteolysis), and collagenases–> damage small blood vessels, cartilage, ligaments, tendons, bones; THESE PROCESS LIMIT THE JOINTS ROM

Question 23

What are the early and late characteristics of RA?

Answer 23

early: morning stiffness, weight loss, and fatigue; late: severe pain, joint instability, and crippling deformities

Question 24

What is the concern with arthritis of the cricoarytenoid joint of the larynx?

Answer 24

40% of RA patients; obstructs airflow; red, swollen on DL; difficult intubation; symptoms= larynx tenderness, hoarseness, painful swallowing radiating to ear, dyspnea or stridor

Question 25

What is Sjogren's Syndrome?

Answer 25

a systemic autoimmune disease in which immune cells attack and destroy exocrine glands that produce tears and saliva; immunologically mediated lacrimal and salivary gland destruction

Question 26

Does Sjogren's primarily affect men or women?

Answer 26

9/10 are women; and is often associated with other autoimmune disorders (SLE and RA)

Question 27

What are the symptoms of Sjogren's Syndrome?

Answer 27

Sicca symptoms such as xerophthalmia (dry eyes; "xero" tears), xerostomia (dry mouth), and parotid gland enlargement (major human salivary gland)

Question 28

What is scleroderma?

Answer 28

sclerosis of the skin; disease associated with immune dysregulation and several autoantibodies; injury to vascular endothelial cells--> leakage of serum proteins--> tissue edema--> lymphatic obstruction--> fibrosis; poor prognosis

Question 29

What is the treatment for scleroderma?

Answer 29

NO drugs or treatments are effective

Question 30

What are the characteristics of scleroderma?

Answer 30

inflammation, vascular sclerosis, and fibrosis of skin and viscera; from stoelting: characterized by inflammation, vascular sclerosis, and fibrosis of the skin and viscera (may evolve into CREST)

Question 31

What is the etiology of scleroderma?

Answer 31

unknown; but characteristics of both a collagen vascular disease and autoimmune; age 20-40; women>men; pregnancy accelerates disease in 50% of patients; prognosis is poor and r\t extent of visceral involvement

Question 32

What are anesthetic considerations with scleroderma?

Answer 32

plan for difficult airway; oral or nasal telangiectasias (may bleed profusely); thick skin so difficult line insertion; contracted intravascular volume--> hypotension; pulmonary aspiration; decreased pulmonary compliance requires increased pressures; supplemental O2; prevent increased PVR; sensitive to respiratory depressant effects of opioids

Question 33

_______ is an autoimmune disorder characterized by weakness and easy fatigability of skeletal muscle.

Answer 33

Myasthenia Gravis

Question 34

What causes the weakness associated with myasthenia gravis?

Answer 34

autoimmune destruction of post-synaptic AcH receptors at the NMJ---> reduced numbers of receptors and degradation of their function, and to complement-mediated damage to post-synaptic end plate The complement system helps or “complements” the ability of antibodies and phagocytic cells to clear pathogens from an organism. It is part of the immune system called the innate immune system[1] that is not adaptable and does not change over the course of an individual's lifetime. However, it can be recruited and brought into action by the adaptive immune system.

Question 35

_______ is a chronic autoimmune disorder caused by a decrease in functional AcH receptors at the NMJ resulting from their destruction or inactivation by IgG antibodies.

Answer 35

Myasthenia Gravis; up to 80% of functional AcH receptors can be lost; women 20-30, men >60yo

Question 36

What are the hallmarks of Myasthenia Gravis?

Answer 36

weakness and rapid exhaustion of voluntary muscles with repetitive use followed by partial recovery with rest

Question 37

What is a crisis that may require mechanical ventilation and should be expected in any patient with respiratory failure of unknown origin?

Answer 37

myasthenia gravis crisis

Question 38

What drug class is prescribed most often to treat muscle weakness in myasthenia gravis?

Answer 38

anticholinesterase: increase acetylcholine at NMJ through inhibition of end plate acetylcholinesterase; pyridostigmine is prescribed most often

Question 39

What are some anesthetic considerations for MG?

Answer 39

marked respiratory depression with opioids and benzos; unpredictable response to Sux, may increase to 2mg/kg to overcome any resistance but expect prolonged effect; if respiratory muscle or bulbar involvement there is increased risk of pulmonary aspiration--> metoclopramide, H2, or PPI; very sensitive to NDMB... try to avoid or give very small doses; at risk for post-op resp failure

Question 40

How is MG classified?

Answer 40

by distribution and severity; class I-V.... limited to extraocular muscles to severe form of muscle weakness resulting from progression of type 1 and 2 and resp failure

Question 41

What are the s/s of MG?

Answer 41

periods of exacerbation and remission; function may be normal after rest but weakness after exercise; PTOSIS (eyelid drooping) and DIPLOPIA (double vision) are most common initial complaints; arm, leg, and trunk weakness is usually asymmetrical; muscle atrophy does not occur

Question 42

What are some exacerbating factors of MG?

Answer 42

infection, electrolyte abnormality, pregnancy, emotional stress, and surgery

Question 43

What medications can aggravate muscle weakness in MG?

Answer 43

antibiotics, especially aminoglycosides (amikacin, tobramycin, streptomycin, gentamycin)

Question 44

What is the treatment for MG?

Answer 44

1st line is anticholinesterase drugs--> pyridostigmine; cholinergic crisis with higher dosages (confirmed by significant muscarinic side effects and accentuated muscle weakness after edrophonium); immunosuppresive therapy (corticosteroids, cyclosporin); plasma phoresis (removes antibodies from circulation.... used for prep for thymectomy)

Question 45

Considerations for thymectomy....

Answer 45

preop should include optimizing strength and resp function; avoid immunosuppressants; plasmaphoresis if vital capacity <2L; median sternotomy vs mediastinoscopy; full benefit is often delayed for months after surgery; IV IgG is reserved for acute exacerbation and crisis

Question 46

What is the Tensilon test?

Answer 46

differentiates b\w myasthenic crisis and cholinergic crisis: accentuated muscle weakness after edrophonium confirms cholinergic crisis; Myasthenic crisis= UNDERDOSING; Choninergic crisis= OVERDOSING myasthenic crisis: severe exacerbation of myasthenic symptoms.... quadriparesis or plegia, resp insufficiency, diff swallowing, 3-4 hours after taking medication cholinergic crisis: extreme weakness plus muscarinic s\e.... abdominal cramping, diarrhea, salivation, bradycardia, miosis; 30-60 min after taking medication

Question 47

What is Eaton-Lambert syndrome (AKA Myasthenic Syndrome)?

Answer 47

A rare autoimmune disorder characterized by muscle weakness of the limbs; resembles myasthenia gravis; acquired autoimmune disease characterized by the presence of IgG antibodies to voltage sensitive calcium channels

Question 48

What are the s\s of Eaton-Lambert syndrome?

Answer 48

proximal limb weakness, exercise improves strength, muscle pain common, reflexes absent or decreased

Question 49

Eaton Lambert vs Myasthenia Gravis?

Answer 49

EL is decreased release of AcH.... and MG is decreased number of AcH receptors; EL improves with exercise, MG declines with exercise and improves with rest; EL is sensitive to Sux and NDMB, but MG requires higher dose of sux but very sensitive to NDMB

Question 50

What are some anesthetic consideration of Eaton Lambert?

Answer 50

sensitive to succinylcholine and NDBD; poor response to anticholinesterases d\t decreased AcH to have affect on NMJ

Question 51

What are some characteristics of Grave's disease?

Answer 51

thyrotoxicosis (state of thyroid hormone excess); systemic autoimmune disease; caused by thyroid stimulating antibodies that bind to TSH receptors in the thyroid.... increasing T4 & T3; thyroid is usually 2-3x normal size; increased BP, CO, HR; MVP, A fib; diagnosis confirmed by presence of thyroid stimulating antibodies in the context of low TSH level and increased T4 and T3

Question 52

What are some anesthetic consideration of Grave's disease?

Answer 52

ensure euthyroid; evaluate airway; avoid SNS activation and sympathomimetic drugs; careful titration of muscle relaxants; position carefully; monitor for s\s of thyroid storm; pad and protect eyes

Question 53

What is thyroid storm?

Answer 53

rare event caused by acute stress; life threatening tachycardia, hyperthermia, HTN, AFIB, sweating, tremor, vomiting, weakness, agitation, shock CHF, metabolic acidosis

Question 54

How do you treat thyroid storm?

Answer 54

administer antithyroid meds and provide hemodynamic support; carefully titrate beta adrenergic blockers and potassium iodide; hydration with glucose containing crystalloids; acetaminophen for antipyretic; adequate oxygen

Question 55

What is the most common for of hypothyroidism in the U.S.?

Answer 55

Hashimoto's thyroiditis

Question 56

What is Hashimoto's thyroiditis?

Answer 56

autoimmune mediated destruction of thyroid gland; goiter formation is common; slowed metabolism; dry skin, cold intolerance, paresthesias, slow mental functioning, ataxia, puffy face (myxedema), constipation; hypersomnolent with decreased ventilatory response to hypoxia and hypercarbia; pleural, pericardial, and peritoneal effusions; labile BP, CAD, bradycardia

Question 57

What are some anesthetic considerations for Hashimoto's thyroiditis?

Answer 57

delay if severely symptomatic; evaluate airway; monitor for exaggerated CNS depression with anesthetic agents; coexisting muscle weakness so titrate muscle relaxants carefully; possible decreased hepatic metabolism and renal excretion; keep normothermic

Question 58

What is a branch of the vagus nerve (10th cranial nerve) that supplies motor function and sensation to the larynx (voice box)?

Answer 58

recurrent laryngeal nerve; travels within the endoneurium

Question 59

Why is it essential that patients presenting for a thyroidectomy be in a euthyroid state?

Answer 59

because SNS hyperactivity is associated with increased levels of thyroid hormone

Question 60

What is the purpose of a NIM tube?

Answer 60

nerve integrity monitor; inserted to help surgeons assess the potential for RLN injury

Question 61

Describe the basic anatomy of the thyroid.

Answer 61

butterfly shaped and composed of 2 lobes connected by a median tissue mass named the thyroid isthmus; largest endocrine (secrete products or hormones directly into blood rather than through a duct) gland in the body

Question 62

Which thyroid hormone is most abundant?; most potent?

Answer 62

T4 (thyroxine) 90%, T3 (triiodothyronine) 10%; major hormone secreted by thyroid gland is T4.... most of T3 is formed by the conversion of T4 to T3 in target tissues; high potency in T3 results in production of 80% of the metabolic activity; T3 has higher affinity for binding and is 10 times more metabolically active than T4..... despite the high degree of protein binding, it is the unbound or free T3 that provides the majority of metabolic effects; most tissues contain enzymes needed to convert T4 to T3

Question 63

Describe the synthesis of thyroid hormones.

Answer 63

iodide is ingested in diet--> absorbed by GI tract into blood--> iodide is transported from plasma into the colloid of the follicle--> iodide is converted to iodine by thyroid peroxidase (process known as iodide trapping)--> iodine molecules attach to amino acid tyrosine on the thyroglobulin molecule--> thyroxine is formed when 2 diiodotyrosine compounds are linked, and T3 is composed of diiodotyrosine and monoiodotyrosine

Question 64

Where is Thyrotropin Releasing Hormone secreted from?

Answer 64

hypothalamus; it stimulates the production of TSH by anterior pituitary gland

Question 65

What is myxoedema?

Answer 65

severe hypothyroidism

Question 66

What is thyrotoxicosis?

Answer 66

a hypermetabolic clinical syndrome which occurs when there are elevated T3 and T4 levels; hyperthyroidism is ONE CAUSE of thyrotoxicosis;

Question 67

What are some manifestations of hypothyroidism?

Answer 67

myocardial depression, decreased spontaneous ventilation, abnormal baroreceptor function, reduced plasma volume, anemia, hypoglycemia, hyponatremia, impaired hepatic drug metabolism

Question 68

What is included in the supportive management for a thyroid crisis?

Answer 68

hydration, cooling, inotropes, and formerly steroids; beta-blockade and antithyroid drugs are 1st line of treatment; some studies have shown dantrolene as useful in treating thyroid crisis

Question 69

Why would magnesium sulfate seem like a reasonable treatment for thyroid crisis?

Answer 69

since thyroid hormones sensitize the adrenergic receptors to endogenous catecholamines, magnesium sulfate would seem useful..... b\c it reduces the incidence and severity of dysrhythmias caused by catecholamines

Question 70

What is the most preferred method of anesthesia for a thyroidectomy?

Answer 70

general; regional is not routinely used and is reserved for particular circumstances.... bilateral deep or superficial cervical plexus block

Question 71

What are contraindications to using an LMA for thyroidectomy?

Answer 71

tracheal narrowing and/or deviation; risk that LMA will be displaced during surgery and laryngospasm occurs in relation to surgical manipulation

Question 72

What consideration in tracheal tubes would you consider if you suspect tracheal compression before a thyroidectomy?

Answer 72

wise to select a small reinforced tube ; 6% of tracheal intubations for thyroid surgery will be difficult

Question 73

Describe patient positioning for a thyroidectomy.

Answer 73

sandbag b\w shoulder blades and head resting on horse shoe or Whitlock head rest; 25 degree upward tilt of head will assist venous drainage; slight head extension will assist surgeon access to thyroid

Question 74

What are some concerns and s\s of retrosternal enlargement of thyroid?

Answer 74

compression of mediastinal structures; dyspnea, choking, hoarseness

Question 75

What is a parasympathetic concern with dissection of the neck?

Answer 75

may stimulate carotid sinus and this, coupled with median sternotomy, can produce profound vagal stimulation leading to bradycardia and even sinus arrest

Question 76

What is MEN 2?

Answer 76

multiple endocrine neoplasia: associated with risk of early medullary thyroid cancer; aka pheochromocytoma and amyloid producing medullary thyroid carcinoma; can be benign or malignant; generally occurs in endocrine glands (thyroid, parathyroid, adrenal); subtype of MEN; most cases derive from a variation in the RET PROTOONCOGENE All types of MEN2 include pheochromocytoma and medullary thyroid carcinoma; MEN2a also includes parathyroid hyperplasia; MEN2b also includes mucocutaneous neuroma, GI symptoms, and muscular hypotonia

Question 77

Why is the former practice of a "partial thyroidectomy" rarely being performed today?

Answer 77

due to complications that often occur during surgery for recurrent goiter..... at least a total thyroid lobectomy should be performed

Question 78

What are some post-op risks following a thyroidectomy?

Answer 78

hematoma, RLN damage (unilateral hoarseness, bilateral stridor), tracheomalacia (tracheal collapse), laryngeal edema (may involve larynx giving a hoarse voice), hypocalcemia (20% occurrence following removal of large multi-nodular goiter.... only 3.1% remained permanently hypocalcemic), wound complications (rare), PONV (high risk), post-op pain (usually require minimal post-op analgesia)

Question 79

What are associated risk factors of RA?

Answer 79

70% associated with HLA-DR4 subtype; 80% are seropositive for Rheumatoid factor; unidentified viral or bacterial agents, female gender (3x more common.... 30-55yr), family history, food allergy and intolerance, altered gut flora, psychological stress, exposure to heavy metals and cigarette smoking

Question 80

According to the article on RA, what are the common clinical manifestations of RA?

Answer 80

symmetrical pattern of joint pain (worse in morning and improves with activity), morning stiffness, fatigue, weight loss, general malaise, depression, disability; soft tissue swelling, warmth, tenderness on pressure or movement, deformities and nodules; progressive joint damage with severe disability in 10% of patients

Question 81

What is the prevalence and areas of concern with extra-articular involvement of RA?

Answer 81

>50% of patients overall; cardiovascular system (coronary heart disease, endocarditis, LV failure, myocarditis, effusions), lungs (restrictive defect, rheumatoid nodules, pleural effusion), skin, eyes, bone marrow, kidneys, nerves---> anemia, chronic renal failure from drug treatment (25%), hepatomegaly, increased serum fibrinogen and alpha-1 acid glycoprotein, decreased serum albumin, peripheral neuropathy, autonomic dysfunction

Question 82

What are manifestations of cricoarytenoid joint involvement in RA patients?

Answer 82

dyspnea, stridor, hoarseness, and occasionally severe upper airway obstruction

Question 83

What is the suggested pragmatic approach for the use of complete flexion/extension cervical spine X-rays in pre-op for patients with RA?

Answer 83

patients with pain radiating to the occiput (the EARLIEST and MOST COMMON symptom of cervical spine instability), paresthesia to shoulders and arms with head movement, or painless sensory loss in hands SHOULD have pre-op flexion/extension cervical spine x-rays

Question 84

What is the concern with long-term steroid therapy in patients with RA?

Answer 84

causes adrenal suppression and patients taking an equivalent dose greater than prednisolone 10mg daily require steroid to cover; patients taking steroids and NSAIDs are at risk of developing GI tract bleeding and should receive gastric acid prophylaxis

Question 85

What is the difference in osteoarthritis and rheumatoid arthritis?

Answer 85

osteoarthritis: most common; mechanical wear and tear cause; develops slowly; little to no joint swelling; symptoms often begin on one side of the body and may spread to the other; usually limited to one set of joint (finger joints closest to fingernail or thumb.... large weight bearing joints--hip, or spine); morning stiffness 1 hour; generally feeling of fatigue or illness