Pediatric Asplenia Treatment & Management

Once the diagnosis of anatomic or functional asplenia is confirmed, aggressive management is the key to decreasing the morbidity and mortality associated with this condition. Newborn diagnosis of sickle cell disease is essential because the first manifestation of the hemoglobinopathy in these infants may be an asplenia-related fatal bacteremia. Any episode of fever or signs of infection should be promptly and aggressively treated.

Medical care involves 4 key components: antibiotic prophylaxis, appropriate immunization, aggressive management of suspected infection, and parent education.

• Antibiotic prophylaxis

  • Antibiotic prophylaxis should be initiated immediately upon the diagnosis of asplenia because these patients are at significant risk of pneumococcal infections. For children younger than 2 years, oral penicillin V may be given twice a day. Amoxicillin has also been recommended as an appropriate prophylactic antibiotic. Erythromycin is an alternate choice in patients who are allergic to penicillin.
  • In general, antimicrobial prophylaxis should be considered for all children with asplenia or splenic dysfunction until age 5 years and for at least 1 year after surgical splenectomy. Some experts recommend continuing prophylaxis into adulthood, particularly for high-risk patients.
  • Numerous controversies surround when to discontinue antimicrobial prophylaxis in asplenia and hyposplenia (if it should be discontinued at all). Arguments for cessation of prophylaxis include poor patient compliance and the development of resistant bacterial strains in patients on daily antibiotics. Those in favor of lifelong prophylaxis cite case reports of overwhelming postsplenectomy sepsis that occurs years after removal of the spleen. Currently, most guidelines leave the option open to continue lifelong prophylaxis based on the clinical circumstances of the individual patient.
• Immunization^[7]

  • All patients should receive all standard childhood and adolescent immunizations at the recommended age. Most importantly, vaccinations against encapsulated organisms, including pneumococcal conjugate and/or polysaccharide, H influenzae type b conjugate, and meningococcal conjugate and/or polysaccharide vaccines, should be administered on the standard schedule.
  • Approximately 80% of the pediatric pneumococcal bacteremias in the United States are caused by the 7 serotypes covered in the conjugate vaccine: 4, 6B, 9V, 14, 18C, 19F, and 23F. The conjugate vaccine has been effective in dramatically reducing the occurrence of invasive pneumococcal disease. In children younger than 2 years, the incidence of all invasive pneumococcal infections has decreased by 80% after conjugate vaccine was recommended in the routine childhood immunization schedule. Infections caused by vaccine and vaccine-related serotypes have decreased by 90% in older children and adults.
  • The immunization schedule for pneumococcal conjugate vaccine (PCV7) consists of a primary series of 4 doses (0.5 mL each) at age 2, 4, 6, and 12-15 months. Catch-up immunization schedules are published regarding appropriate dosing schedules for children aged 5 years or younger.
  • In February, 2010 the FDA approved a pneumococcal conjugate vaccine covering 13 serotypes (PCV13) for children from 6 weeks to 5 years of age. This will likely replace the 7 serotype vaccine and provide broader coverage against pneumococcus.
  • The pneumococcal polysaccharide vaccine against 23 serotypes (PPV23) should be given after age 24 months for supplemental protection. Children older than 5 years should receive a dose of either PCV7 or PPV23. If both vaccine types are given, PCV7 should be administered first, with administration of PPV23 at least 8 weeks after the last dose of PCV7. A booster dose of PPV23 is appropriate 3-5 years after the first dose.
  • Patients should also receive quadrivalent meningococcal vaccine. Two licensed meningococcal vaccines are available in the United States against serotypes A, C, Y, and W-135, and another vaccine against serotype C is available in Europe. Meningococcal conjugate vaccine (MCV4) is indicated for children aged 2 years or older with increased risk of invasive meningococcal disease. Patients who were previously vaccinated at 7 years old or older should be revaccinated 5 years after their previous meningococcal vaccine. Patients who were previously vaccinated at ages 2-6 years should be revaccinated 3 years after their previous meningococcal vaccine. Patients with asplenia should continue to be revaccinated at 5 year intervals indefinitely.
  • The recommended vaccination schedule for H influenzae type b is a primary series of 3 doses given at age 2, 4, and 6 months or 2 doses given at age 2 and 4 months, depending on the particular conjugate vaccine product administered. A booster dose at age 12 months is recommended for all vaccine products. Children who are undergoing scheduled splenectomy after completion of their primary series and booster dose may benefit from an additional dose of conjugate vaccine at least 7-10 days before surgery. Catch-up immunization schedules regarding H influenzae type b vaccine are published. Patients 5 years or older who never received Hib immunization should receive 1 dose.
  • Yearly influenza vaccine is also recommended to minimize the likelihood of secondary bacterial infections.
  • Children 2 years of age or older undergoing elective splenectomy should receive 1 or both pneumococcal vaccines and the meningococcal vaccine at least 2 weeks prior to surgery. Children younger than 2 years should receive PCV7 (or PCV13) prior to elective splenectomy. Ensure the Hib vaccination series is completed.
• Management of suspected infection

  • The risk of serious bacterial infection is always present in these patients. Many patients have trivial symptoms yet rapidly develop fulminant sepsis and death within hours.
  • All patients with impaired splenic function with suspected infection must be urgently and promptly evaluated. Obtain blood, urine, and, if indicated, cerebrospinal fluid (CSF) cultures. Initiate broad-spectrum intravenous antibiotics effective against S pneumoniae, H influenzae type b, and N meningitidis. Because of the fulminant nature of infections with these agents, intravenous antibiotics need to be initiated before bacteriological results are available. Second-generation or third-generation cephalosporins may be the initial choices. If multiple-drug resistance is a concern, vancomycin should be added to the regimen. In addition, many patients require supportive care with intravenous fluids, volume expanders, and pressor support.
  • Because of the potential rapid progression of a serious bacterial infection, some experts recommend that asplenic patients have access to "stand-by" antibiotics, which can be initiated at the first sign of infection (fever, chills, or malaise). That the initiation of "stand-by" antibiotics is not a substitute for seeking immediate medical attention at the onset of an illness cannot be overemphasized.
  • Patients with asplenia are at an increased risk of sepsis, shock, and meningitis secondary to Capnocytophaga canimorsus resulting from dog, cat, or rodent bites. The diagnosis may be made by means of Gram staining of the buffy coat, blood, and CSF cultures. Early treatment with penicillin is the therapy of choice, but cephalosporins, clindamycin, and erythromycin may also be used.
• Parent education

  • The most important component in the treatment of these patients is parent education. Risks must be explained to all caretakers because they are an integral part of the management team. Seeking medical advice at the first sign of illness is crucial.
  • Ongoing education must become a part of each physician-parent encounter so that the parents remain vigilant, which allows potentially serious infections to be identified early and managed aggressively. The child should wear a Medic Alert bracelet that reads "Asplenia" or "No Spleen." Written instructions should be given to the parents in a form that they can keep with them. For example, they can be given a wallet-sized card with the child's diagnosis and concise guidelines for early treatment and intervention.

• Elective splenectomy for conditions such as hemolytic anemia are strongly discouraged before age 6 years and should be delayed as long as possible.
• Options to splenectomy should be considered when appropriate. These include partial splenectomy or embolization, conservative management of splenic trauma, and autotransplantation.
• To the author's knowledge, no data support the routine use of prophylactic antibiotics in the perioperative period.
• When surgical splenectomy is imminent, administration of pneumococcal, H influenzae type b, and meningococcal vaccines at least 2 weeks before splenectomy, if possible, is appropriate. If the immunizations are not received prior to surgery, some recommend immunization 14-21 days postsurgery because of enhanced immune response, compared with immediately postsurgery.
• Surgical splenectomy in patients with immunodeficiency should be avoided because of increased risk of invasive bacterial infections.

• No restrictions on activities are usually advised.
• Infections with H influenzae type b and pneumococcal and meningococcal bacteria are known to be increased among immunologically competent children and adults in daycare centers, college dormitories, military barracks, and other crowded facilities. Therefore, the risks of these situations should be explained to patients and their families.