Incidence and Management of Overwhelming Post-Splenectomy Infection (OPSI)

Definition and Clinical Significance

OPSI is defined as fulminant sepsis, meningitis, or pneumonia primarily triggered by encapsulated bacteria, with Streptococcus pneumoniae accounting for approximately 50% of cases 1
Other common causative organisms include Haemophilus influenzae type B and Neisseria meningitidis 3
OPSI represents a true medical emergency with mortality rates ranging from 30-70%, with most deaths occurring within the first 24 hours 2

The risk of OPSI and associated death is highest in the first year after splenectomy, but remains elevated for more than 10 years and likely for life 1
Children under 5 years of age have a significantly greater risk of OPSI with increased mortality compared to adults 3
The risk is particularly high in neonates, exceeding 30% 2

Vaccination against encapsulated bacteria (S. pneumoniae, H. influenzae type B, N. meningitidis) is strongly recommended for all asplenic patients 1, 4
Optimal timing for vaccination is at least 2 weeks before elective splenectomy or no sooner than 14 days after emergency splenectomy, as antibody response is suboptimal before this time 2
Annual influenza vaccination is recommended for all asplenic patients over 6 months of age 6, 4
Malaria prophylaxis is strongly recommended for asplenic travelers to endemic areas 3

Antibiotic therapy should be immediately initiated at the onset of any unexplained fever, malaise, chills, or other constitutional symptoms 3
Patients should be provided with emergency standby antibiotics for immediate use when medical review is not readily accessible 3
Primary care providers must be informed of the patient's asplenic status to ensure appropriate care 6

Hyposplenic patients should also be considered at risk and should receive the same preventive measures 2
Current vaccines do not provide complete coverage against all serotypes of encapsulated bacteria, highlighting the need for additional preventive measures 2