Chapter 34: Spleen Flashcards
1
Q
Type of arteries: short gastric and splenic artery
A
End arteries
2
Q
Where is the splenic vein?
A
Posterior and inferior to splenic artery
3
Q
Serves as antigen-processing center for macrophages
A
Spleen
4
Q
Largest producer of IgM
A
Spleen
5
Q
Breakdown of spleen
A
85% red pulp
15% white pulp
6
Q
Function of red pulp
A
Acts as a filter for aged or damaged RBCs (pitting and culling)
7
Q
Red pulp: what is pitting
A
Pitting: removal of abnormalities in the RBC membrane
- Howell-Jolly bodies: nuclear remnants
- Heinz bodies: hemoglobin
8
Q
Red pulp: what is culling
A
Removal of less deformable RBCs
9
Q
Function of white pulp
A
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
Q
An opsonin; facilitates phagocytosis -> produced in spleen
A
Tuftsin
11
Q
Activates alternate complement pathway -> produced in spleen
A
Properdin
12
Q
Occurs in spleen before birth and in conditions such as myeloid dysplasia
A
Hematopoiesis
13
Q
Spleen is a reservoir for __
A
platelets
14
Q
where are accessory spleens found?
A
accessory spleen (20%): most commonly found at splenic hilum
15
Q
indications for splenectomy
A
ITP far greater than for TTP
16
Q
Most common non traumatic condition requiring splenectomy
A
ITP
17
Q
caused by anti-platelet antibodies (IgG) - bind platelets; results in decreased platelets
- petechiae, gingival bleeding, bruising, soft tissue ecchymosis
A
Idiopathic thrombocytopenic purpura (ITP)
18
Q
What causes ITP?
A
from many etiologies: drugs, viruses, etc.
19
Q
What does the spleen look like in ITP?
A
spleen is normal
20
Q
When does ITP usually resolve spontaneously?
A
in children
21
Q
Tx: ITP
A
Steroids (primary therapy); gamma globulin if steroid resistant
22
Q
When is splenectomy indicated in ITP?
A
For those who fail steroids: removes IgG production and source of phagocytosis, 80% respond after splenectomy
23
Q
Pre op management of ITP
A
Give platelets 1 hour before surgery
24
Q
What is thrombotic thrombocytopenic purpura (TTP) associated with?
A
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
