Chapter 34: Spleen Flashcards Preview

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Flashcards in Chapter 34: Spleen Deck (90):
1

Type of arteries: short gastric and splenic artery

End arteries

2

Where is the splenic vein?

Posterior and inferior to splenic artery

3

Serves as antigen-processing center for macrophages

Spleen

4

Largest producer of IgM

Spleen

5

Breakdown of spleen

85% red pulp
15% white pulp

6

Function of red pulp

Acts as a filter for aged or damaged RBCs (pitting and culling)

7

Red pulp: what is pitting

Pitting: removal of abnormalities in the RBC membrane
- Howell-Jolly bodies: nuclear remnants
- Heinz bodies: hemoglobin

8

Red pulp: what is culling

Removal of less deformable RBCs

9

Function of white pulp

Immunologic function; contains lymphocytes and macrophages
- Major site of bacterial clearance that lacks preexisting antibodies
- site of removal of poorly opsonized bacteria, particles and cellular debris
- antigen processing occurs with interaction between macrophages and helper T cells

10

An opsonin; facilitates phagocytosis -> produced in spleen

Tuftsin

11

Activates alternate complement pathway -> produced in spleen

Properdin

12

Occurs in spleen before birth and in conditions such as myeloid dysplasia

Hematopoiesis

13

Spleen is a reservoir for __

platelets

14

where are accessory spleens found?

accessory spleen (20%): most commonly found at splenic hilum

15

indications for splenectomy

ITP far greater than for TTP

16

Most common non traumatic condition requiring splenectomy

ITP

17

caused by anti-platelet antibodies (IgG) - bind platelets; results in decreased platelets
- petechiae, gingival bleeding, bruising, soft tissue ecchymosis

Idiopathic thrombocytopenic purpura (ITP)

18

What causes ITP?

from many etiologies: drugs, viruses, etc.

19

What does the spleen look like in ITP?

spleen is normal

20

When does ITP usually resolve spontaneously?

in children

21

Tx: ITP

Steroids (primary therapy); gamma globulin if steroid resistant

22

When is splenectomy indicated in ITP?

For those who fail steroids: removes IgG production and source of phagocytosis, 80% respond after splenectomy

23

Pre op management of ITP

Give platelets 1 hour before surgery

24

What is thrombotic thrombocytopenic purpura (TTP) associated with?

Medical reactions, infections, inflammation, autoimmune disease

25

Pathophysiology of TTP

Loss of platelet inhibition - leads to thrombosis and infarction, profound thrombocytopenia

26

Purpura, fever, mental status changes, renal dysfunction, hematuria, hemolytic anemia

TTP (thrombotic thrombocytopenic purpura)

27

Tx: TTP

80% respond to medical therapy
- Plasmapheresis (primary); immunosuppression

28

MCC death in TTP

most commonly due to intracerebral hemorrhage or acute renal failure

29

When is splenectomy indicated in TTP?

splenectomy rarely indicated

30

0.1% risk after splenectomy, increased risk in children

post-splenectomy sepsis syndrome (PSSS)

31

most common causes of post-splenectomy sepsis syndrome

1) s pneumoniae
h. influenzae, n meningitidis

32

what is post-splenectomy sepsis syndrome secondary to?

specific lack of immunity (immunoglobulin, igm) to capsulated bacteria

33

post-splenectomy sepsis syndrome is highest in patients...

with splenectomy for hemolytic disorders or malignancy

34

adults vs children: increased risk of mortality after developing post-splenectomy sepsis syndrome

children

35

what is the best age for a child if splenectomy is necessary?

5 years old: allows antibody formation; child can get fully immunized

36

when does post-splenectomy sepsis syndrome occur?

most episodes occur within 2 years of splenectomy

37

prophylactic antibiotic regimen for children

6 months of prophylactic antibiotics (controversial) - to decrease chances of post-splenectomy sepsis syndrome

38

vaccines needed before splenectomy

pneumococcus, meningococcus, h.influenzae

39

definition of hypersplenism

decrease in circulating cell count of erythrocytes and/or platelets and/or leukocytes
- and -
normal compensatory hematopoietic responses present in bone marrow
- and -
correction of cytopenia by splenectomy
- with or without -
splenomegaly

40

two types of hemolytic anemias - membrane protein defects

spherocytosis
elliptocytosis

41

most common congenital hemolytic anemia requiring splenectomy

spherocytosis

42

defect in spherocytosis

spectrin deficit (membrane protein) deforms RBCs and leads to splenic sequestration (hypersplenism)

43

pathophysiology: spherocytosis

causes pigmented stones, anemia, reticulocytosis, jaundice, splenomegaly
- spectrin deficit

44

tx: spherocytosis

splenectomy and cholecystectomy
- try to perform splenectomy after age 5; give immunizations first

45

curative in spherocytosis

splenectomy

46

- symptoms and mechanism similar to spherocytosis; less common
- spectrin and protein 4.1 deficit (membrane protein)

elliptocytosis

47

membrane protein defect: elliptocytosis

spectrin and protein 4.1 deficit

48

hemolytic anemia: non-membrane protein defects

- pyruvate kinase deficiency
- g6pd deficiency
- warm antibody-type acquired immune hemolytic anemia
- beta thalassemia

49

- results in congenital hemolytic anemia
- causes altered glucose mechanism; RBC survival enhanced by splenectomy

pyruvate kinase deficiency

50

mc congenital hemolytic anemia not involving a membrane protein that requires splenectomy

pyruvate kinase deficiency

51

- precipitated by infection, certain drugs, fava beans
- splenectomy usually not required

g6pd deficiency

52

management: warm antibody-type acquired immune hemolytic anemia

indication for splenectomy

53

- HgbA replaced with HgbS
- spleen usually auto infarcts and splenectomy not required

sickle cell anemia

54

most common thalassemia; due to persistent HgbF

beta thalassemia

55

difference between beta thalassemia major and minor

- major: beta chains affected
- minor: 1 chain, asymptomatic

56

is splenectomy required in sickle cell anemia?

spleen usually auto infarcts and splenectomy not required

57

symptoms: pallor, retarded body growth, head enlargement

beta thalassemia

58

management: splenomegaly in beta thalassemia

splenectomy (if patient has splenomegaly) may decrease hemolysis and symptoms

59

cause of death in beta thalassemia

most die in teens secondary to hemosiderosis

60

medical tx: beta thalassemia

blood transfusion and iron chelators (deferoxamine, deferiprone)

61

Symptoms: hodgkin's disease type a

asymptomatic

62

symptoms: hodgkin's disease type b

symptomatic (night sweats, fever, weight loss) --> unfavorable prognosis

63

stage 1: hodgkin's disease

1 area or 2 contiguous areas on the same side of the diaphragm

64

stage 2: hodgkin's disease

2 non-contiguous areas on the same side of diaphragm

65

stage 3: hodgkin's disease

involved on each side of diaphragm

66

stage 4: hodgkin's disease

liver, bone, lung, or any other non-lymphoid tissue except spleen

67

best prognosis: hodgkin's disease

lymphocyte predominant

68

worst prognosis: hodgkin's disease

lymphocyte deplete

69

most common hodgkin's disease

nodular sclerosing

70

tx: hodgkin's disease

chemo

71

mcc of chylous ascites

lymphoma

72

- worse prognosis than hodgkin's; 90% are b-cell lymphomas
- generally systemic disease by the time the diagnosis is made
- tx: chemo

non-hodgkin's lymphoma

73

tx: hairy cell leukemia

rarely need splenectomy

74

causes of spontaneous splenic rupture

mononucleosis, malaria, sepsis, sarcoid, leukemia, polycythemia vera

75

splenic implants; usually related to trauma

splenosis

76

see howell-jolly bodies

hyposplenism

77

most common cause of splenic artery or splenic vein thrombosis

pancreatitis

78

post splenectomy lab changes

increased rbcs.
increased wbcs.
increased platelets.
- if platelets > 1 x 10^6, give ASA

79

#1 splenic tumor overall;
#1 benign splenic tumor

Hemangioma

80

Tx: splenic hemangioma

Splenectomy if symptomatic

81

#1 malignant splenic tumor

non-hodgkin's lymphoma

82

indications for surgery with splenic cysts

surgery if symptomatic of > 10 cm

83

anemia, decreased platelets
- Tx: splenectomy for symptomatic splenomegaly

sarcoidosis of spleen

84

rheumatoid arthritis, hepatomegaly, splenomegaly
- Tx: splenectomy for symptomatic splenomegaly

felty's syndrome

85

tx: splenic abscess

splenectomy usual (bleeding risk with percutaneous drainage)

86

Tx: echinococcal splenic cyst

splenectomy

87

results of splenectomy / hyposplenic condition - erythrocytes

- howell-jolly bodies (nuclear fragments)
- heinz bodies (hemoglobin deposits)
- pappenheimer bodies (iron deposits
-target cells
- spur cells (acanthocytes)

88

results of splenectomy / hyposplenic condition -
platelets

transient thrombocytosis

89

results of splenectomy / hyposplenic condition
- leukocytes

transient leukocytosis
persistent lymphocytosis
persistent monocytosis

90

guidelines for prevention of postsplenic sepsis

- vaccinate with polyvalent pneumococcal vaccine at least 10-14d prior to splenectomy
- if splenectomy urgent: wait 14d post procedure to vaccinate
- for high risk patients (immunosuppressed, children