Fever in the Asplenic Patient
Why we care
- Fever in a patient with impaired splenic function = early sign of sepsis
- Infections in this population can develop precipitously with very minimal antecedent symptoms, and can become fulminant and fatal within hours of symptom onset
- DIC can occur early in the course
Patient population
- Anatomic Asplenia (post-splenectomy, congenital asplenia)
- Functional Asplenia (e.g. sickle cell anemia)
- Hyposplenia (from atrophy, infarction, engorgement, or infiltration of the spleen in chronic dz such as thalassemias, chronic liver disease, HIV/AIDs, immune disorders, or malignancies)
- If splenic function is in question, you can obtain a peripheral blood smear and check for Howell-Jolly bodies. This is specific but not sensitive.
Role of the spleen
- Red pulp: sinusoids filter out larger rigid particles including senescent and/or parasitized red blood cells, as well as unopsonized bacteria. Macrophages here will also eliminate some infected cells or bacteria via phagocytosis, in addition to producing pro-inflammatory cytokines in response to infection
- White pulp: houses half of the body’s immunoglobulin-producing B lymphocytes, which are critical for producing antibodies that target polysaccharide antigens on the surface of encapsulated bacteria
Top Infectious Ddx
- Pneumonia
- Primary Bacteremia
- Meningitis
- The most common pathogens involved are encapsulated bacteria and blood borne parasites, which the spleen has a large role in clearing
Management
**The single most important thing you can do is obtain blood cultures and administer empiric IV antibiotics without any delay**
- At minimum, especially if the sides are busy, I would probably bring this patient into cardiac/resus to get IV access and initiate abx and then consider downgrade if appropriate
- Aplenic patients are advised by their outpatient docs to take an oral antibiotic that they have on hand and present to the nearest ED immediately
- They might have already taken an oral antibiotic but they still need IV antibiotics ASAP
- Do not delay abx for LP
Antibiotic Choice
- Vanc/Ceftriaxone
- Vanc is mostly to cover beta-lactam resistant S.pneumo
- Add anaerobic coverage if concerned for a dog/human bite, so swap CTX with Zosyn
- If recent travel, consider other possible exposures and add the appropriate coverage
- As always, broaden as needed but Vanc/CTX is at minimum
Other treatment considerations
- If concerned for meningitis, give dexamethasone
- Consider giving IVIG
Diagnostics
- CBC, BMP, LFTs
- Blood cultures
- Peripheral blood smear
- Quant IgG
- Strep pneumo urine antigen
- Consider Coags/Fibrinogen/Dimer if concerned for DIC
- CXR, other imaging as is appropriate
- Lumbar puncture – but this is often deferred because patient develops DIC
Disposition: Admission for a minimum of 72 hours
