Autoimmune Disorders (Test 2) Flashcards Preview

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Flashcards in Autoimmune Disorders (Test 2) Deck (85)
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1
Q

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

A

autoimmunity

2
Q

What is the most common chronic inflammatory arthritis?

A

rheumatoid

3
Q

Does RA have a higher incidence in men or women?

A

2-3 x higher in women

4
Q

What are the causes of pericardial effusion?

A

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

5
Q

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

A

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

6
Q

What symptoms characterize RA?

A

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

7
Q

What are treatment options for RA?

A

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.

8
Q

What are some major anesthetic considerations for patients with RA?

A

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

9
Q

What is the most common hematologic abnormality in RA?

A

anemia

10
Q

What is the most common pulmonary complication of RA?

A

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

11
Q

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

A

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

12
Q

What are the airway management concerns with RA?

A

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

13
Q

What is the difference b\w osteoarthritis and RA?

A

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

14
Q

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

A

RA

15
Q

Why does RA typically cause deformity in patients?

A

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

16
Q

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?

A

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

17
Q

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

A

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

18
Q

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

A

GI bleeding, renal toxicity, platelet dysfunction

19
Q

What is an endocrine concern for patients with RA?

A

adrenal insufficiency and impaired immune system (from glucocorticoid therapy)

20
Q

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

A

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

21
Q

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

A

hands, wrist, feet

22
Q

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

A

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

23
Q

What are the early and late characteristics of RA?

A

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

24
Q

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

A

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

25
Q

What is Sjogren’s Syndrome?

A

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

26
Q

Does Sjogren’s primarily affect men or women?

A

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

27
Q

What are the symptoms of Sjogren’s Syndrome?

A

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

28
Q

What is scleroderma?

A

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

29
Q

What is the treatment for scleroderma?

A

NO drugs or treatments are effective

30
Q

What are the characteristics of scleroderma?

A

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)

31
Q

What is the etiology of scleroderma?

A

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

32
Q

What are anesthetic considerations with scleroderma?

A

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

33
Q

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

A

Myasthenia Gravis

34
Q

What causes the weakness associated with myasthenia gravis?

A

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.

35
Q

_______ 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.

A

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

36
Q

What are the hallmarks of Myasthenia Gravis?

A

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

37
Q

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

A

myasthenia gravis crisis

38
Q

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

A

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

39
Q

What are some anesthetic considerations for MG?

A

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

40
Q

How is MG classified?

A

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

41
Q

What are the s/s of MG?

A

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

42
Q

What are some exacerbating factors of MG?

A

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

43
Q

What medications can aggravate muscle weakness in MG?

A

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

44
Q

What is the treatment for MG?

A

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)

45
Q

Considerations for thymectomy….

A

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

46
Q

What is the Tensilon test?

A

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

47
Q

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

A

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

48
Q

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

A

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

49
Q

Eaton Lambert vs Myasthenia Gravis?

A

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

50
Q

What are some anesthetic consideration of Eaton Lambert?

A

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

51
Q

What are some characteristics of Grave’s disease?

A

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

52
Q

What are some anesthetic consideration of Grave’s disease?

A

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

53
Q

What is thyroid storm?

A

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

54
Q

How do you treat thyroid storm?

A

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

55
Q

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

A

Hashimoto’s thyroiditis

56
Q

What is Hashimoto’s thyroiditis?

A

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

57
Q

What are some anesthetic considerations for Hashimoto’s thyroiditis?

A

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

58
Q

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

A

recurrent laryngeal nerve; travels within the endoneurium

59
Q

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

A

because SNS hyperactivity is associated with increased levels of thyroid hormone

60
Q

What is the purpose of a NIM tube?

A

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

61
Q

Describe the basic anatomy of the thyroid.

A

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

62
Q

Which thyroid hormone is most abundant?; most potent?

A

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

63
Q

Describe the synthesis of thyroid hormones.

A

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

64
Q

Where is Thyrotropin Releasing Hormone secreted from?

A

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

65
Q

What is myxoedema?

A

severe hypothyroidism

66
Q

What is thyrotoxicosis?

A

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

67
Q

What are some manifestations of hypothyroidism?

A

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

68
Q

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

A

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

69
Q

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

A

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

70
Q

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

A

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

71
Q

What are contraindications to using an LMA for thyroidectomy?

A

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

72
Q

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

A

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

73
Q

Describe patient positioning for a thyroidectomy.

A

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

74
Q

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

A

compression of mediastinal structures; dyspnea, choking, hoarseness

75
Q

What is a parasympathetic concern with dissection of the neck?

A

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

76
Q

What is MEN 2?

A

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

77
Q

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

A

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

78
Q

What are some post-op risks following a thyroidectomy?

A

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)

79
Q

What are associated risk factors of RA?

A

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

80
Q

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

A

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

81
Q

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

A

> 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

82
Q

What are manifestations of cricoarytenoid joint involvement in RA patients?

A

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

83
Q

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

A

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

84
Q

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

A

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

85
Q

What is the difference in osteoarthritis and rheumatoid arthritis?

A

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