The spleen has a major role to play in protecting the body from overwhelming bacterial infection. It removes bacteria from the circulation by means of phagocytosis and produces specific antibodies. Consequently, asplenic patients are at risk of overwhelming post-splenectomy infection (OPSI).
My awareness of this was raised by the receipt of an information leaflet which detailed the tragic story of a young father of two who had died of OPSI within 24 hours of feeling unwell with a 'trivial' sore throat.
He had not been advised of his eight-fold increased risk of developing severe septicaemia, nor of the advisability of vaccination and antibiotic prophylaxis to protect him from OPSI.
The risks of OPSI can be reduced by:
- Vaccination against pathogens causing infections in asplenic patients.
- Antibiotic therapy: long-term prophylactic and emergency use.
- Improved patient education.
- Increased awareness of OPSIamong doctors called upon to treat and advise asplenic patients.
Streptococcus pneumoniae causes about 10% of cases of septicaemia and 20% of cases of bacterial meningitis. The risk of severe infection is increased 50-fold in children who are asplenic and eight-fold in adults.
Pneumovax vaccine contains purified capsular polysaccharide from the 23 most prevalent serotypes. It is more than 90% effective in healthy adults under 55 years of age. Revaccination every 5-10 years is currently recommended, athough more frequent revaccination may be necessary in asplenic patients or those with an underlying disease process that causes immunosuppression.
Haemophilus influenzae type b (Hib) vaccination
All asplenic patients who have not previously been immunised should have a single dose of Hib vaccine.
The vaccine covers groups A and C. Protection lasts one year and is not routinely recommended for asplenic patients unless they are travelling to areas of increased risk .
Yearly influenza vaccination is recommended for asplenic patients.
Prophylactic antibiotics should be given to all asplenic children up to the age of 16. Adults undergoing splenectomy who are otherwise fit should be offered at least 2 years' prophylactic antibiotics. Asplenic adults with impaired immunity should have lifelong antibiotic prophylaxis.
The recommended prophylaxis for asplenic patients is shown in Table 1.
Table 1: Recommended antibiotic prophylaxis in asplenic patients*
|Standard prophylaxis||Penicillin allergy|
|Adult (>12 years)||Phenoxymethylpenicillin 500mg bd||Erythromycin 500mg bd|
|Child 6-12 years||Phenoxymethylpenicillin 250mg bd||Erythromycin 250mg bd|
|Child 5 years||Erythromycin 125mg bd||Phenoxymethylpenicillin 125mg bd|
* For early treatment, amoxicillin is preferred, because of its more predictable absorption and higher serum levels
Those who decline prophylactic antibiotics should be provided with fresh supplies of antibiotic which they can institute at the first sign of infection. All such patients should be advised to seek early medical advice in these circumstances.
Asplenic patients who are found to be unwell in these circumstances should be treated as emergencies and given intravenous antibiotic, as in cases of suspected meningitis, and be admitted to hospital immediately for further assessment and treatment.
Asplenic patients are at greater risk of falciparum malaria, Capnocytophagia canimorsus infection (after dog bites) and babesiosis (from tick bites). Adequate prophylaxis and antibiotic therapy are therefore essential.
This is vitally important if the incidence of OPSI is to be reduced. All patients should preferably be counselled and immunised preoperatively and details of vaccinations sent to their GP on discharge.
Ideally, patients should wear a Medic-Alert bracelet.
|Figure 1: The two sides of a laminated card for asplenic patients to record vaccination details, available from the DoH|
|Figure 2: The two sides of a patient information sheet on splenectomy, available from the DoH|
The medical records of all patients known to have had a splenectomy, in our practice of 9500, were reviewed. Details of the patients' immunisation and antibiotic history were noted.
A standard letter was sent to each patient detailing their individual vaccination and antibiotic needs and inviting them to attend the GP of their choice for advice.
All of the partners had access to detailed advice on the vaccination and antibiotic recommendations specified by the local departments of public health.
To offer all asplenic patients:
- A consultation with the GP of their choice to discuss OPSI
- Pneumococcal vaccination
- Hib vaccination
- Influenza vaccination
- Long-term prophylactic/emergency antibiotic therapy as appropriate.
- The practice has 15 asplenic patients, including a medical student who was unaware of the advisability of vaccination and antibiotic prophylaxis before coming to the practice on a 3-week student attachment. The indications for splenectomy and the age range of the patients are shown in Figures 3 and 4.
- One patient had not been offered immunisation by the hospital services although he had undergone splenectomy only 3 years ago.
- Nine patients had not requested influenza vaccination the previous year.
- One patient had not attended for advice despite several letters of invitation.
- Eight patients did not have emergency supplies of antibiotic.
|Figure 3: Indications for splenectomy in the asplenic patients (n=15)|
|Figure 4: Age range of the asplenic patients (n=15)|
- A surgery poster will be placed in the patient waiting area so that patients or their relatives may advise staff of asplenic patients not on the audit database.
- Every year, patients will be sent a letter advising them of the immunisations/antibiotic cover Phey require, and inviting them to see the GP of their choice to discuss these.
- All patients will be offered influenza vaccination yearly.
- All patients attending opportunistically should be asked if they have 'fresh' emergency antibiotic supplies.
- All asplenic patients' notes will be marked to alert staff to the risk of OPSI.
- All staff involved in giving travel advice will be made aware of the increased risk of malaria and meningitis in this group of patients, and advise them accordingly.
- All new patients found to have had a splenectomy will have their notes directed to me for audit and entry onto the recall database.
Feedback from the asplenic patients in the practice, has been very favourable, especially from those who had not been offered vaccination previously and were unaware of their increased risk of septicaemia.
We were pleased that 14 of the 15 patients contacted attended for advice and vaccination.
All doctors should be aware of the risks of OPSI in asplenic patients and actively seek to advise patients of the means of prevention. We hope that, through this audit, no patient will die as a result of OPSI or ignorance of the means of its prevention.
Specialist advice and further information are available from our consultant microbiologist colleagues in local hospitals.
- Acknowledgements: Dr Simon Hill, Consultant Microbiologist, Poole Hospital, Dorset.