Guidelines for the prevention of
sepsis in asplenic and hyposplenic patients
Dr Sally Roberts
Outline
Guidelines for the prevention of sepsis in asplenic and hyposplenic patients
Dr Sally Roberts
For more infomation:
- The Victorian Spleen Registry http://www.baysidehealth.org.au/infectious_diseases_unit/
- Journal article. Guidelines for the prevention of sepsis in asplenic and hyposplenic patients.
Intern Med J. 2008 May;38(5):349-56
Introduction
- Role of the spleen
- Asplenia and hyposplenia
- Sepsis in patients post-splenectomy or with hyposplenism
- Vaccines
- Evidence
- Recommendations in the NZ setting
Role of the spleen
- Secondary lymphoid tissue
- Important filtration site for clearance of microbial pathogens
- Not a site for lymphatic drainage
- Antigens, bacterial and cells enter via the splenic artery
- Red and White pulp
- Red – macrophages and red cells
- White – T cells proximal to central arteriole surrounded by aggregates of B cells
Structure
Function
- Spleen receives about 5% of total cardiac output per minute
- 90% of this blood enters the “open circulation” systems of sinusoids of the red pulp →venous sinuses
- During this process splenic macrophages remove defective blood cells and other particles such as bacteria and parasites
- Main site for the synthesis of IgM antibody, tuftsin and properdin
- Maintains survival of IgM memory B cells.
Removal of pathogens
- Bacteria
- Opsonisation of antibody-coated and complement-coated bacteria
- Intracellular pathogens → T cell mediated cytolytic killing
- Viruses
- T cell mediated cytolytic killing
Definitions
- Asplenia
- Absence of spleen
- Congenital
- Surgical
- Hyposplenism
- Loss of function
- Filtering role – Howell-Jolly bodies, acanthocytes, target cells, Heinz bodies, Pappenheimer bodies, leucocytosis and thrombocytosis
- Fighting infection
Causes of hyposplenism
- Common cause
- Coeliac disease
- Sickle cell anaemia
- Alcoholism
- Lupus
- Post-BmTx
Overwhelming post-splenectomy infection (OPSI)
- Clinical features
- No obvious primary source
- Short, non-specific prodromal phase
- Massive bacteraemia
- Septic shock with DIC
- Waterhouse-Fredrichsen syndrome
- Death may ensue in 24-48 hours
- High mortality (50 to 70%)
OPSI
- Risk
- 0.42 per 100 person years (Australia)
- 0.18 – 7.6 per 100 person years
or
- 3.2-4.4% in asplenic/hyposplenic children <16 years
- 0.9% in asplenic/hyposplenic adults
- Mortality
- Overall 40-50%
OPSI
- Bacterial pathogens
- Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis
- Capnocytophaga caniomorsus, Babesia spp., Bordetella holmseii
- Salmonella spp. in children with SCD
- Duration of risk
- ??
- First few years vs lifelong
Prevention
v Vaccination
- Live, killed, subunit vaccines
- Polysaccharide vaccines
- – induce T-cell-independent immune responses (B cell) that do not produce booster effects
- Protein vaccines
- T-cell-dependent immune responses with immunologic memory, boost on repeat injection
- Education
- Victorian Spleen Registry
- Long-term antibiotics
Pneumococcal vaccine
- 23-valent polysaccharide
- Older children and Adults
- 7-valent pneumococcal conjugate vaccine
- Children <9 years
- T-cell-mediated immune memory
- Australia and NZ
- 2-3 doses of conjugate 2-6/12, then 23vPPV at 2 years
- Different schedule for older children
- Adults
- 23vPPV – 2/52 post splenectomy
- Revaccinate in 5 years
Haemophilus influenzae vaccine
- H. influenzae serogroup b
- Added to the national immunization schedule in 1982
- Vaccine - polysaccharide molecule linked to a protein
- If vaccinated pre-splenectomy do not require vaccine
- Use in unvaccinated adults unclear
Meningococcal vaccination
- Evidence for increased risk is poor
- Quadrivalent (A,C,W,Y135) polysaccharide vaccine
- Protein conjugate Meningococcal C vaccine
- Recommendations
- Australia
- Conjugate C followed by Quadrivalent
- New Zealand
- Quadrivalent
Further strategies
- Alerts
- Medical records
- Travel to countries with malaria
- Avoid animal bites
- Asplenic registry
Education
- All patients and families educated about potential risks
- Medialert
- Good communication between medical carers
- Prompt presentation following onset of symptoms
Antibiotic Use
- Prophylaxis
- Data from children with SCD
- Standby treatment
Adherence to Guidelines
ANZ J Surg 2006; 76: 542-7
- Retrospective review
- N= 111 patients with splenectomy
- Post-trauma 32
- haematological 32
- Surgery 24
- Iatrogenic 12
- Others 11
- Education 22%
- Vaccination for all three bacteria 84%
- Prophylactic antibiotics for 1-2 years – 67%
Victorian Spleen Registry
spleenregistry@alfred.org.au
- Regular updates about relevant health information
- Yearly reminder for influenza vaccine
- Travel advice
- Cost effective
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Ministry of Health
