emDOCs Podcast – Episode 75: Asplenia

Today on the emDOCs cast with Brit Long, MD (@long_brit), we look at asplenia and its complications.

Episode 75: Asplenia



  • Asplenia is complete loss of the spleen’s function.
    • Anatomic splenectomy:  spleen has been surgically removed.
    • Functional splenectomy: spleen is present but not working.
      • The classic example is sickle cell disease (SCD).
      • Patients with SCD develop functional asplenia by 3-5 years of age.
  • Hyposplenia is reduced splenic function.
    • Numerous chronic medical conditions can cause this:  chronic liver disease, HIV, malignancies, thalassemia, celiac disease, ulcerative colitis, sarcoidosis, amyloidosis, lupus, and rheumatoid arthritis.



  • 1 million people in the U.S. are asplenic, and 22,000 splenectomies are performed annually.


Spleen Anatomy and Physiology:

  • Immune and hematologic functions are carried out in the red and white pulp.
    • White pulp
      • Largest number of B cells in the body, which are important for antibody production.
      • Releases components of alternate complement pathway, makes neutrophils, natural killer cells, monocytes, serum opsonins and cytokines, all of which help in removing harmful bacteria.
    • Red pulp
      • Filters and removes old blood cells and harmful microorganisms.
  • The one organ capable of removing encapsulated organisms.
    • Streptococcus pneumonia, H. influenza, Neisseria, Capnocytophaga, E. coli, Pseudomonas
  • Primary site of serum IgM antibody production.
  • Plays important roles in cytokine production and the complement cascade.


Identifying Asplenic Patients

  • Anatomically asplenic patients should wear a medical bracelet and carry an ID card.
    • If they are unable to provide a history:
      • Look for Howell-Jolly bodies on peripheral smear.
      • Look for depressions on RBC membranes. These suggest hyposplenism if over 4% of RBCs have this feature.
      • Ultrasound can be used to evaluate for presence/absence of a spleen.


Clinical Issues for Patients with Asplenia

  • Infection
    • 2-3 times increased risk of infection, sepsis, and mortality.
    • Pneumonia, meningitis, sepsis, and atypical infections are all more common.
    • If an asplenic patient develops an infection, they are at 6x higher risk for a subsequent infection for the next 3 years.
  • Overwhelming Post-Splenectomy Infection (OPSI)
    • Risk is highest in anatomically asplenic patients, but can occur in functional or hyposplenic patients.
      • OPSI occurs in 0.5% of asplenic patients.
      • Most common in the first 2 years after splenectomy.
      • Mortality rate is 10-70%.
    • Source of infection varies.
      • May be a common location (UTI, pneumonia), or could involve multiple systems.
      • OPSI may be associated with an atypical location such as septic arthritis or a spinal epidural abscess.
      • Most common causative organism is S. Pneumoniae.  
      • Others include Haemophilus influenzae type b, Neisseria meningitidis,  Capnocytophaga canimorsus, Capnocytophaga cynodegmi, Escherichia coli, and Staphylococcus aureus.
    • OPSI presentation:
      • Presents similar to a viral infection or gastroenteritis initially (fever, chills, myalgias, nausea/vomiting, diarrhea).
      • Patients can become septic and decompensate in hours, developing hypotension, septic shock, ARDS, DIC.
    • Suspected OPSI evaluation:
      • Approach like a patient with neutropenia or septic shock.
        • CBC, CMP, UA
        • Lactate
        • Blood cultures
        • Evaluate for end-organ damage
        • DIC workup with fibrinogen and coagulation panel
        • CXR
        • LP if signs of meningitis
    • OPSI Management:
      • Initiate broad spectrum antibiotics while completing the evaluation.
        • Consider a later generation cephalosporin or carbapenem plus vancomycin or vancomycin plus piperacillin tazobactam and/or azithromycin for atypical pneumonia.
      • Fluids and vasopressors
        • Patients are at risk for adrenal insufficiency. Consider stress dose steroids if the blood pressure does not improve with fluids and vasopressors.
      • For patients with focal infection that are otherwise well appearing, consider hematology consult and have a low threshold for admission.
  • Infection prevention:
    • Vaccines
      • All patients should receive pneumococcal, meningococcal, haemophilus B.
        • Ideally, started 10-12 weeks before elective surgery and completed 2-3 weeks before surgery.
      • For emergency splenectomy, vaccines should be given 2 weeks after surgery.
      • For patients with functional asplenia, vaccines given as soon as possible.
    • Prophylactic antibiotics
      • Daily antibiotic prophylaxis is given for ~1 year after splenectomy.
      • Daily prophylaxis is offered to hyposplenic children <5 years of age.
      • Daily (often lifelong) prophylaxis is offered to those thought to be at high risk:  concurrent immunocompromising conditions or history of sepsis/other severe infection caused by encapsulated organisms.
      • Penicillin and amoxicillin are the preferred agents.
  • Emergency antibiotics for infectious symptoms
    • Patients will have a supply of antibiotics to be used if they develop symptoms of infection such as fever, chills, rigors, etc.
  • Thrombus:
    • Asplenic patients have a higher risk of atherosclerosis, CAD, stroke, limb ischemia, MI, DVT, PE, and portal vein thrombosis.
      • Incidence of thrombotic events is 10-37%
    • Patients post splenectomy are at highest risk in the months following surgery.
    • Functional asplenia also carries an increased risk of thrombosis.
    • Evaluation and treatment similar to those with normal spleen function.
  • Pulmonary Hypertension (PH)
    • Elevated pulmonary arterial pressures are found in 8-11.5% of asplenic patients. Incidence is higher in patients who have chronic disease states like SCD or thalassemia.
    • Presentation: non-specific symptoms including dyspnea, fatigue, chest pain, syncope, and peripheral edema.
    • Diagnosis: ECG, ultrasound, CT.
    • Management:
      • Delicate balance of improving RV function and systemic perfusion while avoiding hypoxia, hypercarbia, hypotension, and mechanical ventilation if possible.
      • Optimize fluid status with diuresis or small fluid boluses and vasopressors.
    • Consider ICU admission and involving pulmonology/critical care colleagues.



  1. Long B, Koyfman A, Gottlieb M. Complications in the adult asplenic patient: A review for the emergency clinician. Am J Emerg Med. 2021 Jun;44:452-457. PMID: 32247651.

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