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42 Cards in this Set
- Front
- Back
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What are Howell-Jolly bodies?
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nuclear remnants (clusters of DNA) from RBCs
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The spleen provides both nonspecific and specific immune responses. What are the 2 arms of the non-specific response?
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• clearance of opsonized particles and bacteria by fixed splenic macrophages
• opsonin production |
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What is an opsonin?
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any molecule that acts as a binding enhancer for the process of phagocytosis
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What some opsonins produced by the spleen and what are their specific functions?
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• fibronectin
• properdin: activated the alternative pathway of the complement system • tuftsin: facilitates macrophage phagocytosis |
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What is the most useful imaging technique to determine splenic size and detect injury?
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CT scan
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What are indications for splectomy?
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• hematologic disorders
• hypersplenism (associated with other disease) • leukemia & lymphoma • splenic rupture • other (ex. abscess, tumors, cysts, splenic artery aneurysm) |
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What are examples of hematologic disorders that could be treated by splenectomy?
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• hemolytic anemias
• hereditary spherocytosis • hereditary elliptocytosis • ITP • thalassemia minor & major • thrombocytopenia • TTP |
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What is the most common reason for splenectomy?
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trauma
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True/False: The spleen is the most commonly injured organ after blunt abdominal trauma
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The correct answer is: True
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True/False: The spleen is the most commonly injured organ after penetrating abdominal trauma
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• The spleen is the 2nd most commonly injured organ after penetrating abdominal trauma
• The correct answer is: False |
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What are the 3 general mechanisms of splenic injury?
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• penetrating
• blunt compressive • blunt deceleration |
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Describe a grade I splenic injury
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• hematoma: subcapsular < 10% surface area
• laceration: < 1 cm deep |
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Describe a grade II splenic injury
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• hematoma:
- subcapsular 10%-50% surface area - parenchymal < 5 cm diameter • laceration: 1-3 cm deep, not involving trabecular vessels |
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Describe a grade III splenic hematoma
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• hematoma:
- subcapsular > 50% surface area - parenchymal > 5 cm diameter - hematoma can be expanding or ruptured • laceration: > 3 cm deep or involving trabecular vesselsq |
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Describe a grade IV splenic injury
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laceration of segmental vessels inovlved with devascularization < 50%
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Describe a grade V splenic injury
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• completely shattered spleen
OR • hilar vascular injury with devascularization |
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What is a Kehr's sign?
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severe left shoulder pain in patients with splenic injury (due to referred pain from diaphragmatic irritation)
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What is a Ballance's sign?
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percussion dullness of the left flank in patients with splenic injury
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What is a splenorrhaphy?
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operative repair of the spleen
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What is the most common reason for an asplenic state?
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splenectomy
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Differentiate between hypersplenism and splenomegaly
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• hypersplenism is excess function of the spleen
• splenomegaly is anatomic enlargement of the spleen |
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What are characteristics of hypersplenism?
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• cytopenia: anemia, leukopenia, & thrombocytopenia (either alone or in combination)
• normal or hyperplastic cellular precursors in bone marrow |
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How does hypersplenism cause cytopenia?
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• increased sequestration of the cells in the spleen
• increased destruction of cells by the spleen • production of antibodies in the spleen, leading to increased sequestration and destruction |
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What is hereditary spherocytosis?
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• a deficiency in spectrim (a membrane component that is essential for deformability)
• RBC are rigid and cannot pass into the splenic sinuses and become sequestered in the red pulp |
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What are examples of hemolytic anemias caused by metabolic abnormalities?
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• pyryvate kinase deficiency
• glucose-6-phsophate dehydrogenase (G6PD) deficiency |
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True/False: Hemolytic anemias caused by metabolic abnormalities are not responsive to splenectomy
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The correct answer is: True
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What are examples of hemoglobinopathies that can be treated with splenectomy?
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• Sicke cell (more useful early in the disease)
• Thalassemias (are at high rish for overwhelming postsplenectomy infection) |
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Patients with autoimmune hemolytic anemia (Coob's test positive) are treated first-line with corticosteroids and treatment for any unerlying disorders. When would splenectomy be indicated in these patients?
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• when steroids are ineffective
• when high doses are required • when toxic side effects develop during steroid treatment |
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Which type of autoimmune hemolytic anemia is more likely to respond to splenectomy, anemias associated with warm reactive antibodoes (IgG) or cold reactive antibodies (IgM)?
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Warm reactive antibodies (IgG)
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What is the treatment for ITP?
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• corticosteroids (inital treatment)
• splenectomy (if unresponsive to corticosteroids) |
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What are clinicial features of TTP?
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• fever
• purpura • hemolytic anemia • neuroligc manigestations • signs of renal disease |
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When is splenectomy indicated for hypersplenism?
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• platelet count is < 50,000 with evidence of bleeding
• neutrophil count is < 2000 • pt has anemia requiring blood transfusion |
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What is Felty's syndrome?
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• neutropenia
• rheumatoid arthritis • splenomegaly |
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When is splenectomy performed to treat Felty's syndrome?
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when severe recurrent infection or intractable leg ulcers occur
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True/False: Splenectomy is not indicated for acute leukemia
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The correct answer is: True
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When is splenectomy indicated for chronic leukemia?
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• for some cases of hypersplenism
• for symptoms associated with massive splenomegaly |
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What are hematologic changes that occur after splenectomy?
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• WBC increases (usually returns to normal in 5-7 days)
• peripheral smear shows Howell-Jolly bodies, Pappenheimer bodies, & pitted red cells • platelets increase (usually returns to normal in 2 weeks) |
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Which patients are at the highest risk of postsplenectomy sepsis?
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patients who undergo splenectomy for hematologic disorders
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Overwhelming infections in post-splenectomy patients are usually caused by encapsulated organisms. List examples of encapsulated organisms.
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• Strep pneumoniae (most common)
• H. flu • N. meningitidis • ß-hemolytic strep • Staph aureus • E. coli • Pseudomonas |
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What are examples of parasitic inections that can cause an overwhelming infection in a post-splenectomy patient?
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• Babesiosis
• Malaria |
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What are vaccines that should be given to after splenectomy?
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• polyvalent pneumococcal polysaccaride vaccines
• H. Flu vaccine • N. meningitidis vaccine |
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What is the most common problem after splenectomy?
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atelectasis
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