Post splenectomy infection Dr. M. Shahparianpour.
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Transcript of Post splenectomy infection Dr. M. Shahparianpour.
Post splenectomy infection
Dr. M. Shahparianpour
Spleen
consists of the capsule and trabeculae which enclose the pulp.
3 zones of the pulp
a. White pulp – lymph node; contains lymphocytes, macrophages, and plasma cells in a reticular network
b. Red pulp – consists of the cord and sinuses; contains the cellular elements of the blood
c. Marginal zone – poorly defined vascular space between pulps; contains sequestered foreign material and plasma as well as abnormal cellular elements
histology
The role of the spleen in the prevention of
bacterial infections
It acts as an endothelial filtration organ for bacteria and other foreign material through:
phagocytosis and the production of opsonins including antigen-specific IgM, alternate complement components, properdin, and tuftsin
One of its most important immune functions is responding to blood-borne particulate antigens in the nonimmune host.
The spleen provides the most effective primary IgM response to encapsulated bacteria
There also seems to be a relationship between the quantity and quality of spleen and protection against sepsis:
splenic function after subtotal splenectomy for splenic injury is preserved and may be adequate to prevent severe postsplenectomy sepsis
The propensity for pneumococcal infections in patients with sickle cell disease underscores the importance of qualitative splenic function to protect against sepsis
Etiology of asplenia and hyposplenia
Asplenia refers to the absence of the spleen. The most common cause of asplenia is
surgical removal of the spleen:
Hypersplenism accounts for up to 50% of splenectomies, whereas trauma accounts for 10% to 30%
A rare cause of asplenia is congenital agenesis of the spleen.
This may occur as an isolated finding or as part of a syndrome often associated with cardiovascular abnormalities, such as Ivemark’s syndrome.
Hyposplenism refers to a poorly functioning, but intact spleen
Functional aspleniaAutoimmune DiseasePBCSLE Sjogrens
Intestinal DisorderCeliac diseaseCrohn’sUC
Haematological DiseaseSickle cellEssential thrombocytopenia
Infiltrative DiseaseAmyloidSarcoidosis
NeoplasiaBreast CancerHaematological malignancy
MiscellaneousAlcoholismBMTTPNSplenic Thrombosis
The risk of developing severe infection remains a significant complication of asplenia (surgical splenectomy or congenital asplenia) and hyposplenia,
especially in children under the age of 5 years
Splenic salvage methods (eg, partial splenectomy) are practiced with specific indications, the goal being to preserve some of the splenic immune function.
Whether partial splenectomy renders the same risk of developing overwhelming postsplenectomy sepsis (OPSS) as total splenectomy and whether the same preventative measures should be taken, remain unclear.
Definition of OPSI
OPSI may have a short prodrome with non-specific symptoms
Evolve into septic shock and DICClinical course measured in hours rather
than daysFever most common – most report rigors
1 - 2 days prior to presentation In adults OPSI usually cryptic infection
without primary source
It is well known that asplenia or hyposplenia convey an increased lifetime risk of developing severe infections to an affected individual, regardless of:
age, the cause of asplenia or hyposplenia, in the case of splenectomy, the duration
of time from removal of the spleen
the incidence seems to be related to age and underlying disease :
Splenectomized children under the age of 15 years are at greater risk of developing OPSS than adults
The incidence of OPSS is higher in children with
underlying hemoglobinopathies (thalassemia major and sickle cell disease) and hereditary spherocytosis than in those who undergo splenectomy because of trauma
Risk of OPSI can be stratified according to underlying disease
Low risk Trauma
Intermediate risk
SpherocytosisITPPortal Hypertension
High risk
Thalassaemiasickle cell diseaseHodgkin's DiseaseMalignancy
Risk of post splenectomy sepsis low but carries high risk of death (50-80%)
If patients are educated to seek attention immediately may be reduced to about 10%
More than 50% who die do so within 48 hours of admission
Children: 1/175 patient yearsAdults: 1/400~500 patient yearsHighest risk at first few years
1/3 at first year1/2 at first 2 yearsHowever, 1/3 after first 5 years
Can happen even 20 years after splenectomy
Clinical manifestations Fever
Any fever must be viewed as possible PSS
BacteremiaCoagulopathy
Purpura, petechiaeMeningitis
Headache, neck stiffness, seizureRespiratory symptoms
Cough, dyspnea, respiratory failureGI symptoms
Nausea, vomiting, diarrhea, GI bleedingShock
The mortality rate of sepsis associated with asplenia or hyposplenia remains high; death occurs in 50% to 70% of those afflicted
Mortality rates are also age related, with the highest rates reported in those children less than 2 years of age
Common pathogens
Encapsulated pathogenStreptococcus pneumoniae(50~60 %)
No particular serotype is more commonHaemophilus influezae(20~30 %)Neisseria spp.(10~20 %)Other uncommon pathogens:
Capnocytophaga canimorsus Common flora in oral cavity of dogs and cats
Bordetella holmesii
Capnocytophaga canimorsus
LABCBCBlood smearDIC profileLumbar punctureCXRBlood culture
ManagementBraod-spectrum antibiotics
Based on expert opinionMust cover:
penicillin-resistant pneucoccus beta-lactamase producing H.influenzae
General suggestionCeftriaxone + VancomycinLevofloxacin + Vancomycin
Life-support measuresH/D or CVVH for ARFVentilatorInotropic agentsFluid
Prevention Avoid unnecessary splenectomy
ImmunizationTiming
14 days before splenectomy 14 days after splenectomy (not immediately)
Pneumococcal vaccine PPV-23 for adults PCPV-7 for children and some adults
Haemophilus B vaccineMeningococcal vaccineRe-immunizationOther vaccines: influenza vaccine
Antibiotic prophylaxisDaily penicillin
Reduce incidence by halfReduce mortality by 80 percentsLife-long or 3~5years?Post PSS patients
Abx for feverOn handEmpirical: Augmentin, Cefuroxine,
fluoroquinolones
When fever, Take the drug and go to doctor without delay
Abx for dental procedures
Not recommended for no obvious advantage
Influenza
Annual Influenza vaccine
HiB Vaccine
Previously non immunised adults should receive a single dose of vaccine.
Meningitis C vaccine
Previously non immunised adults should receive a single dose of vaccine
If poor response give conjugate (Prevenar) if not already given.
Anti-malarialsif travelling to endemic areasMeningitis A+C,W135,Y if appropriateAntibiotics‡
Good response recheck antibody titre in 1 year
Antibiotic cover
3 day supply of Amoxycillin should be kept by the patient with instructions to take 1gm at first sign of infection and 500mg tds thereafter and to seek immediate medical attention.
Check antibodies 4/52 post vaccination
ImmunisationAntibiotics
Travel †
Pneumococcal vaccine
Polysaccharide vaccine (Pneumovax). Avoid in pregnancy.
Poor response revaccinate and re-test at 4/52
Antibiotic prophylaxis (adult dose)
Penicillin V 500mg b.d.Amoxycillin 500mg bd(Erythromycin 250mg od if penicillin allergy)
Absent or dysfunctional spleen in adults
†Discuss with Adult Infectious Disease team
‡Antibiotic prophylaxis may need altering depending upon local resistance.
Malaria
Lack of splenic clearance of leads to high parasitaemia
Increased risk of fulminant malaria
Antibiotic Prophylaxis 1. All patients, regardless of underlying condition, should be on lifelong antibiotic prophylaxis. This should be either Penicillin V or Amoxycillin,
with a preference for Penicillin V. Adult doses:
Penicillin V 500 mg b.d. Amoxycillin 500 mg o.d.
2. For penicillin allergic patients, Erythromycin 250
mg b.d. should be used.
3. Patients travelling to areas where penicillin-resistant pneumococci have been identified should be
switched from Penicillin V to Amoxycillin before travelling and for one week after return.
Immunization4. Asplenia in itself is not a contraindication to routine immunization.
Normal inoculations, including live vaccines, can be given safely to adults with absent or dysfunctional spleens. 5. All splenectomised patients and those with functional hyposplenism should receive pneumococcal immunisation; Haemophilus influenzae type B [Hib] conjugate vaccine and conjugated meningococcal C vaccine [MenC] as soon as possible.
For pneumococcal vaccination the 23-polyvalent pneumococcal vaccine [Pneumovax] should be used.
THANKS FOR YOUR ATTENTIONS