Review Question - QID 104733

This patient is scheduled to undergo splenectomy for refractory ITP; given her anticipated asplenic state, she warrants vaccination at least 2 weeks prior to surgery, and 3-5 years of penicillin prophylaxis beginning at the time of surgery.

Asplenic patients are at increased risk for fulminant sepsis from encapsulated organisms, most commonly pneumococcus, haemophilus, and meningococcus. As such, they warrant vaccination against these pathogens, and this is ideally done at least 14 days before a planned splenectomy. Although this is debated, the general practice is to also give adult patients 3-5 years of prophylaxis with penicillin or amoxicillin starting at the time of surgery due to the high risk of infection.

Bridgen discusses the management of patients with hypo- or asplenism. Importantly, they mention re-vaccination against pneumococcus every five years to boost immunity given the high morbidity associated with infection. Roughly 50% of patients with splenic dysfunction are unaware of their condition, and therefore education is an important step in prevention of infection. Although rare, infection with Capnocytophaga canimorsus has been seen in asplenic patients after contact with dogs, and patients should be cautioned about interacting with pets.

Fabris et al. retrospectively analyzed a cohort of patients with chronic ITP undergoing splenectomy to assess favorable prognostic factors for response in platelet counts. Interestingly, the only factor associated with response was age less than 40 years; other variables, such as patient sex, initial platelet count, and years of thrombocytopenia were not predictive.

Illustration A shows a peripheral blood smear from a patient with asplenia. It shows the characteristic feature of these patients, Howell-Jolly bodies, which are remnants of nuclear material. Normally, these inclusions are removed by the spleen.

Incorrect Answers:
Answers 1,2 and 4,5: These describe the incorrect timing of vaccines and duration of penicillin prophylaxis. As described above, vaccines should be administered at least 14 days prior to splenectomy, and penicillin prophylaxis should be initiated at the time of surgery and continued for 3-5 years in adult patients.