The splenectomised patient

Section: Critical care Curriculum: Curriculum, page 48

Related topics

• Splenomegally
• Elective Splenectomy
• Spleen anatomy

Physiological role of the spleen

• Areas
  • White pulp
    • Found in the inner region of the spleen
    • Opsonisation of extracellular organisms e.g. encapsulated bacteria, by B lymphocytes
      • Leading to antigen production and triggering the immune response
  • Red pulp
    • Site of blood filtration and haemolysis
    • Platelet sequestration and storage
  • Marginal zone
    • Surrounds the white pulp
    • Antigen presenting cells to initiate lymphocyte activation FISH - Filtration, Immune, Sequestration, Haemolysis

Role of the spleen in certain haematological disorders

• Specifically
  • Hereditary Spherocytosis
  • Immune thrombocytopenic purpura

Role of the spleen in certain infectious conditions

• Specifically
  • Malaria
    • Spleen sequestors damaged/infected erythrocytes via
      • Non immune - loss of erythrocyte deformability
      • Immune - AB coated erythrocytes (opsonized)
    • Chronic malaria leads to splenomegaly
    • Rarely can lead to splenic rupture
  • Infectious mononucleosis
    •  Triad of fevеr, tonsillar рharуngitiѕ, and lуmрhаԁеոорath
    • Caused by Epstein-Barr Virus (EBV) (90%)
      • Similar clinical syx can be caused by CMV, Toxoplasma, HIV
    • Splenomegaly
      • 50-60% of cases
      • Due to proliferation of infected B lymphocytes, activations of cytotoxic T cells and increased activity of macrophages
      • Rarely can lead to splenic rupture

Consequences of splenectomy

Pathophysiology

• Defective Complement cascade activation
• Reduced immunisation response to new antigen
• Lower IgM levels
• Reduced neutrophil function
• Reduced production opsonin

Clinical

• OPSI
  • Life threatening syndrome which can occur in asplenia of any cause
  • Generalized flu like prodrome leading into systemic deterioration
  • Caused by
    • Lose opsonizing filter function
    • Delayed and impaired immunoglobulin production
    • No splenic macrophages
• Perform an abdominal examination to identify splenomegaly
  • Normal spleen is up to 12cm (1x3x5 inches) and weighs 70-200g (7 ounces)
  • Splenomegaly - 12-20cm and weighs 500g
  • Massive splenomegaly - >20cm and weighs >1kg
• Palpate from RLQ to LUQ with patient on right lateral positiion
• Percuss and measure as well

Other

• Select appropriate pathology and imaging investigations prior to elective splenectomy
  • Dependent on pathology
  • Bloods which can be specialised for haematological issues
  • Imaging
  • Howell Jowell bodies to confirm asplenia
• Prescribe appropriate preventive management for overwhelming postsplenectomy infection (OPSI) following splenectomy including antibiotics and immunisation
  • OPSI can occur following splenectomy due to the loss of the splenic immunosurveillance functions
    • Local guidelines?
    • Antibiotics
      • Prophylaxis - Amoxicillin for 3-5 years
      • Emergency - in case develops sx despite prophylaxis
    • Vaccinations against
      • Haemophilus influenza type b - Hib
      • Pneumoccocus - PCV20
      • Neiserria meningitidis
      • Flu vaccine
      • Covid 19 vaccine
    • Should get them either 2-4 weeks prior to elective or 2 weeks after emergency splenectomy
    • Medic alert bracelet

Indications for elective splenectomy

• Red Cell
  • Hereditary spherocytosis
  • Thalassaemia
  • Sickle cell disease
  • Autoimmune haemolytic anaemia (AHA)
  • Myelofibrosis
• White Cell
  • HL
  • NHL
  • Leukaemia
  • Platelet
    • ITP
    • TTP
• Other
  • Trauma
  • Cysts
  • Abscess
  • Isolated splenic vein thrombosis?
  • Malignancy