Asplenia refers to the absence ('a-') of normal spleen function and is associated with some risks. Asplenia may be congenital (congenital asplenia), or acquired through surgery (splenectomy) or through processes that destroy the spleen, generally through its function to filter the blood and therefore referred to as auto_splenectomy (eg spherocytosis and sickle cell anaemia).

Asplenia increases the risk of septicaemia from encapsulated bacteria, and can result in a syndrome known as overwhelming post splenectomy infection (OPSI) which can kill within a few hours. In particular patients are at risk from pneumococcus, but also Haemophilus influenzae & meningococcus.

Antibiotic prophylaxis

Because of the increased risk of infection, physicians administer oral antibiotics as a prophylaxis after a surgical splenectomy. The duration suggested varies: one suggestion is that antibiotics be taken for two years or until the age of sixteen years old is reached, whichever is longer.

Patients are also cautioned to take antibiotics at the first onset of an upper or lower respiratory tract infection (for example, sore throat or cough), or at the onset of any fever.

Antibiotic prophylaxis is also needed before certain surgical and dental procedures.

Vaccinations

It is suggested that splenectomized persons receive the following vaccinations:

• pneumococcus every 6 years (a conjugated form is used for children under 2 years)
• Haemophilus influenzae
• meningococcus conjugate vaccine (interval depends on travel plans)
• annual flu vaccinations (to help prevent getting secondary bacterial infection).

The risk to asplenic patients has been expressed as equivalent for a child to die in home accident, and for adults dying in a road traffic accident (reference UK Splenectomy Trust Advice) - so sensible precautions are needed, but no panic.

Hyposplenism

Hyposplenism is the condition where the spleen is poorly-functioning but not as severely affected as with asplenism.

External links

• Medik.Info Word-document factsheet (http://www.medik.info/MI_Asplenia_OPSI.doc)