Spleen registry may help reduce the incidence of overwhelming postsplenectomy infection in Victoria

Overwhelming postsplenectomy infection (OPSI) is a well recognised long-term risk in patients who have undergone splenectomy. In addition, there are patients who are asplenic for other reasons, including congenital asplenia or medical conditions such as coeliac or sickle cell diseases.1 The incidence of OPSI can be reduced by instituting a suite of preventive measures,2 although auditing has shown that adherence to recommendations is poor, both in Australia and elsewhere.3-5

Partly in response to these studies, a number of national and international guidelines have been published, including recent guidelines produced by the Australasian Society for Infectious Diseases.6 In Victoria and elsewhere, there have been more systematic efforts, including the establishment of registries for people who are asplenic. Our case illustrates the risk of OPSI, and, below, we describe how this risk can be minimised.

Although an individual’s risk for OPSI is only in the order of one in 500 patients per year, this carries a 50% chance of mortality for those affected,6 and a risk of significant morbidity. The cost to the health system of an individual case of OPSI can be significant, and systematic approaches to prevention are cost-effective.7 Guidelines based on the limited evidence available usually recommend a combination of vaccination and long-term antibiotic prophylaxis, plus the supply of emergency antibiotics and, possibly most importantly, patient and family education about health after, and the possible consequences of, splenectomy.1,6,8 In retrospective studies, adherence to these guidelines appeared to reduce the rate of OPSI by about 50%.2

As was the case in our patient, most cases of OPSI are due to S. pneumoniae.6 Vaccination against this organism is important, as is vaccination against Neisseria meningitidis and Haemophilus influenzae type b, and vaccination with the influenza vaccine (Box 1). Prophylactic long-term antibiotic therapy is also recommended (Box 1), on the basis of a similar level of evidence. Lack of antibiotic prophylaxis is associated with increased risk.2,3 If patients cannot tolerate long-term prophylaxis, an emergency supply of antibiotics and information on when to take these may be an appropriate alternative.6,8 Education is also important in recognising signs of infection and the need for early presentation to medical care. Insufficient medical advice to patients and their treating medical practitioners, and forgetting this advice, have been purported to be responsible for cases of OPSI occurring decades after the original splenectomy.3 Education also includes the need for travel advice, especially to areas where malaria exists, and consideration of antibiotic therapy after animal bites or other trauma.

Poor adherence to guidelines has given rise to the suggestion that an active spleen registry may be the best option to ensure adherence to best-practice recommendations.9 There are few previous reports of spleen registries, and those that exist show that registries vary in their methods of operation.10

The Victorian Spleen Registry was established in 2003 with funding from the Victorian Government Department of Human Services for an initial 18-month period. The registry team includes the registry coordinator, infectious disease physicians, clinical haematologists and a clinical immunologist, with additional advice received from surgeons, pharmacists and anatomical pathologists. The registry actively enrols asplenic patients; referral and patient consent are required for inclusion. Patients enrolled on the registry are provided with written information about the management of asplenia, and provided with memory aids such as refrigerator magnets and wallet-sized cards. More than 1000 patients are now enrolled. However, continuing funding for the registry is an ongoing problem.

This case and others, like the one illustrated in Box 2, show the severity of even non-fatal OPSI when it occurs, and the real need to minimise the risk to patients by ensuring that they receive regular vaccination, appropriate antibiotic advice and education, as provided in a registry setting.

2 Middle-aged woman after overwhelming postsplenectomy infection

This patient had not had all the necessary vaccinations; she survived, but required amputation of all four limbs.