Spleen Flashcards
What is the size of a normal spleen? Moderate splenomegaly? Severe splenomegaly?
Normal spleen (not splenomegaly) = < 11cm in largest dimension Moderate splenomegaly : 11-20cm (some say > 13cm in craniocaudal height) Severe splenomegaly : >20cm
What is massive splenomegaly?
When the spleen is 5 std dev above the mean normal volume, when the spleen reaches the iliac crest, longer than 18cm, crosses the midline or weights more than 1000-1500 g
What are the ligaments to the spleen? Which ones are vascular and what vessels do they hold?
1) gastrosplenic (contains short gastrics and left gastroepiploic artery) 2) splenocolic 3) splenophrenic 4) splenorenal [aka. lienorenal ligament] (contains splenic artery, splenic vein, and tail of paincreas]
What are some common causes of enlarged spleen?
Hereidtaroy spherocytosis Sickle cell disease thalassemia Hodgkins lymphoma & Non-Hodjkins lymphoma Acute myeloid leukemia, chronic myeloid leukemia, and chronic lymphocytic leukemia Glucose-6-phosphase dehydrogenase (G6PD) deficiency Immune (idiopathic) thromboctyopenic purpura
What are some hematologic diseases associated with hemolytic anemia?
sickle cell disease beta thalassemia Hereditary spherocytosis
What are the ethnic origins of some hematologic diseases associated with hemolytic anemia?
- Sickle cell disease = African descent - Beta thalassemia = Mediterranean, Southeast Asian, African - Hereditary spherocytosis = Northern european
What is the inheritance pattern of the thalassemias?
autosomal dominant
What is the inheritance pattern of hereditary spherocytosis?
autosomal dominant
What is the inheritance pattern of G6PD deficiency?
x-linked recessive
What is the inheritance pattern of sickle cell disease?
autosomal recessive
What is a differential for patients with isolated thrombocytopenia?
heparin-induced thrombocytopenia viral infection cirrhosis pregnancy/preeeclampsia hypersplenism autoimmune disease thrombocytopenic purpura/hemolytic uremic syndrome ITP (diagnosis of exclusion)
In a patient with hemolytic anemia, what are indications for splenectomy?
1) symptomatic splenomegaly/hypersplenism refractory to medical mangagement 2) ITP AND [refractory to steroids, platelet count < 10k for 6 weeks, pregnant women failed steroids/IVIG w/ plt < 10K or < 30K w/ bleeding] 3) hereditary spherocytosis
What age do you perform splenectomy for hereditary spherocytosis?
> 5 y/o; Goal is to preserve immune function and reduce risk of splenectomy sepsis.
For patients under going splenectomy, when do you vaccinate the patient? What do you vaccine them against?
- Vaccination 2 weeks prior to surgery or 2 weeks after surgery - Vaccinate against Haemophilus influenza type B, Streptococcus pneumoniae (pneumococcus), and Neisseria meningitides (menigococcus)
What are the specific vaccinations for each of the organisms in the post-splenectomy vaccine prophylaxis?
o Streptococcus pneumoniae - Polyvalent pneumococcal vaccine (Pneumovax 23) o Haemophilus influenzae type B - Haemophilus influenzae b vaccine (HibTITER) o Neisseria meningitidis - Age 16-55: Meningococcal (groups A, C, Y, W-135) polysaccharide diphtheria toxoid conjugate vaccine (Menactra) - Age >55: Meningococcal polysaccharide vaccine (Menomune-A/C/Y/W-135)
What is the route and when do you revaccinate each of the post-splenectomy vaccinations?
- Polyvalent pneumococcal 0.5 mL SC = Q6 years - Quadravalent meningococcal/diphtheria conjugate 0.5 mL IM upper deltoid = q3-5 years - Quadravalent meningococcal polysaccharide 0.5mL SC = q3-5 years - Haemophilus b conjugate 0.5 mL IM= NO revaccination required