II. Causes: Hyposplenism or Asplenism
- Common Surgical Causes
- Splenectomy
 - Partial Splenectomy
 
 - Common Medical Causes
 - Other Causes of Hyposplenism
- Cyanotic heart disease
 - Ulcerative Colitis
 - Whipple's Disease
 - Chronic active hepatitis
 - Acute Alcohol Abuse
 - Hemoglobinopathy
 - Primary Thrombocythemia
 - Fanconi's Syndrome
 - Malignant histiocytosis
 - Rheumatoid Arthritis
 - Grave's Disease
 - Sarcoidosis
 - Splenic arterial or venous Occlusion
 - HIV Infection
 - Total Parenteral Nutrition
 - High dose Corticosteroids
 
 
III. Pathophysiology: High Risk Organisms
- Encapsulated Bacteria
 - 
                          Gram Negative Bacteria
                          
- Capnocytophaga canimorsus (Dog Bites)
 
 - Intraerythrocytic Parasites
- Plasmodia falciparum (Malaria)
 - Babesia Microti (Babesiosis)
 
 - Less common organisms
- Group B Streptococcus
 - Enterococcus
 - Bacteroides
 - Salmonella
 - Bartonella
 - Plesiomonas shigelloides
 - Eubacterium plauti
 - Pseudomonas pseudomallei
 
 
IV. Diagnostics to identify Hyposplenism
- Step 1: History suggests possible Hyposplenism
- Known post-Splenectomy: See Management below
 - Possible Hyposplenism: Go to Step 2
 
 - Step 2: Peripheral Smear shows Howell-Jolly Bodies
 - Step 3: Abdominal Ultrasound if smear positive
 - Step 4: Radionuclide liver-Spleen scan
- Normal Uptake
- Normal splenic function
 
 - Decreased or absent splenic uptake
- See management below
 
 
 - Normal Uptake
 
V. Management: Prevention
- Initial Immunizations
- Timing
- Preferred >14 days before elective splenectomy
 - Otherwise administer at least 14 days after splenectomy
 
 - Immunizations
- Pneumococcal Vaccine
- Pneumococcal Conjugate Vaccine (e.g. PCV21)
 - PPV-23 (Pneumovax) for adults and children who received PCV13 or PCV15
- Dual Immunization with Pneumovax is not required if PCV20 or PCV21 given
 
 
 - Meningococcal Vaccine
- Quadrivalent Meningococcal Conjugate Vaccine or MCV4 (e.g. Menactra, Menveo)
- Two dose series (with 2 month interval) and
 - Future boosters every 5 years
 
 - Serotype B Meningococcal Vaccine (e.g. Trumenba, Bexsero)
- Recommended in addition to MCV4 for those over age 10 years
 
 
 - Quadrivalent Meningococcal Conjugate Vaccine or MCV4 (e.g. Menactra, Menveo)
 - Haemophilus B Conjugate Vaccine
- Primary Series in children (four doses)
 - No guidelines on booster Immunization in Asplenic adults
 
 
 - Pneumococcal Vaccine
 
 - Timing
 - Repeat Immunizations
- Influenza Vaccine each year
 - Repeat Pneumococcal Vaccine (PPV-23) after age 10 years
- Every 5 years for most Asplenic patients
 - Every 3 years for early waning Antibody titers
 
 - Repeat Quadrivalent Meningococcal Conjugate Vaccine or MCV4 (e.g. Menactra, Menveo)
- Every 5 years
 
 
 - Documentation and Education
- Medic-Alert Bracelet
 - Update medical record
- Vaccinations
 - Asplenism
 
 - Patient educated on infectious risks of Asplenism
- Immediate evaluation for febrile illness
 - Notify dentists and doctors of Asplenic state
 - Exposure risks
- Travel (Malaria)
 - Tick Bites (Ehrlichia and Babesiosis)
 - Dog Bite
 
 
 
 
VI. Management: Antibiotics for prophylaxis or as Stand-by at first signs of infection
- 
                          Antibiotics: Daily prophylaxis
- Amoxicillin
 - Penicillin
 - Trimethoprim-Sulfamethoxazole (Bactrim)
 
 - 
                          Antibiotics: Stand-by Antibiotics
- Amoxicillin-Clavulanate
 - Cefuroxime (Zinacef)
 - Levofloxacin (Levaquin) - in adults
 
 - Protocols
- Children with Asplenism or Hyposplenism
- Daily Prophylaxis
 - Duration controversial (options below)
- First 2-5 years after splenectomy
 - Continued until age 21 years
 - Continue daily prophylaxis if history of Overwhelming Postsplenectomy Infection
 
 
 - Adults with Asplenism or Hyposplenism
- Continue daily prophylaxis if history of Overwhelming Postsplenectomy Infection
 - Standby Antibiotics taken at first signs infection (fever)
 - Immediate medical evaluation mandatory
- Well-appearing: Obtain cultures and continue Antibiotics for 7-10 days
- Consider 24 hour follow-up
 
 - Suspect Sepsis: Admit immediately, culture and start IV broad spectrum Antibiotics
 
 - Well-appearing: Obtain cultures and continue Antibiotics for 7-10 days
 
 
 - Children with Asplenism or Hyposplenism
 
VII. Management: Acute Infection
VIII. References
- Pasternack (2018) UpToDate, Prevention of Sepsis in Asplenic patient, accessed 3/1/2018
 - Brigden (2001) Am Fam Physician 63(3):499-506 [PubMed]
 - DeRossi (1996) J Am Dent Assoc 127:1359-63 [PubMed]
 - Doll (1987) South Med J 80:999-1006 [PubMed]
 - Rubin (2020) N Engl J Med 371(4): 349-56 [PubMed]
 - Sumaraju (2001) Infect Dis Clin North Am 15(2):551-65 [PubMed]
 - (1996) BMJ 312:430-4 [PubMed]