More for Darren and

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From another Chapter in on's Online:

" The most serious consequence of splenectomy is increased

susceptibility to bacterial infections, particularly those with

capsules such as Streptococcus pneumoniae, Haemophilus

influenzae, and some gram-negative enteric organisms.

Patients under age 20 years are particularly susceptible to

overwhelming sepsis with S. pneumoniae, and the overall

actuarial risk of sepsis in patients who have had their spleens

removed is about 7% in 10 years. The case-fatality rate for

pneumococcal sepsis in splenectomized patients is 50 to 80%.

About 25% of patients without spleens will develop a serious

infection at some time in their life. The frequency is highest

within the first 3 years after splenectomy. About 15% of the

infections are polymicrobial, and lung, skin, and blood are the

most common sites. No increased risk of viral infection has

been noted in patients who have no spleen. The susceptibility to

bacterial infections relates to the inability to remove opsonized

bacteria from the bloodstream and a defect in making antibodies

to T cell–independent antigens such as the polysaccharide

components of bacterial capsules. Pneumococcal vaccine

(23-valent polysaccharide vaccine) should be administered to all

patients 2 weeks before elective splenectomy. The Advisory

Committee on Immunization Practices recommends that even

splenectomized patients receive pneumococcal vaccine with a

repeat vaccination 5 years later. Efficacy has not been proven in

this setting, and the recommendation discounts the possibility

that administration of the vaccine may actually lower the titer of

specific pneumococcal antibodies. A more effective

pneumococcal vaccine that involves T cells in the response is in

development. The vaccine to Neisseria meningitidis should also

be given to patients in whom elective splenectomy is planned.

No other vaccines are routinely recommended in this setting.

Splenectomized patients should be educated to consider any

unexplained fever as a medical emergency. Prompt medical

attention with evaluation and treatment of suspected bacteremia

may be life-saving. Routine chemoprophylaxis with oral penicillin

can result in the emergence of drug-resistant strains and is not

recommended.

In addition to an increased susceptibility to bacterial infections,

splenectomized patients are also more susceptible to the

parasitic disease babesiosis. The splenectomized patient

should avoid areas where the parasite Babesia is endemic (e.g.,

Cape Cod, MA). "