HPB P64 An audit on the appropriate prescribing of antimicrobial prophylaxis and vaccinations in patients who underwent a splenectomy by the hepatobiliary department at University Hospital Southampton between January 2020 and April 2022
Authors: Sarkar Srishti , Charmaine Chan Hu Ying , Arshad Ali 
Published: December 2022

Abstract

Background
Patients who have an absent or dysfunctional spleen are at risk of overwhelming post splenectomy infection (OPSI), a condition associated with high mortality rates. The incidence of OPSI ranges from 0.1% to 8.5% (1). This is most commonly from Streptococcus pneumoniae but also from Haemophilus influenzae type b (Hib) and Neisseria meningitidis (2). These infections can have a sudden onset and run a fulminant course. The highest risk of infection is in childhood, age over 50 years old and in the first two years post splenectomy (3). Indications for splenectomy include trauma and malignancy. It is strongly advised that these patients have antibiotic prophylaxis and appropriate vaccinations administered to reduce the risk of OPSI.
In University Hospital Southampton (UHS), the hepatobiliary department carry out elective splenectomies usually together with distal pancreatectomies and also do emergency splenectomies due to trauma (4). An audit was carried out at UHS to assess prescribing of antimicrobial prophylaxis and vaccinations in patients undergoing elective and emergency splenectomies by the hepatobiliary department at University Hospital Southampton between January 2020 and April 2022.

Methods
Patients who underwent a splenectomy at UHS between January 2020 and April 2022 were selected. The hospital inpatient record (CHARTs), e-prescribing record (JAC) and GP record (CHIE) were used to evaluate if patients received appropriate antimicrobial prophylaxis and appropriate vaccinations as per national and local guidelines detailed below.
For patients undergoing an elective splenectomy, the pneumococcal vaccine (Pneumovax) should be given at least two weeks prior to surgery (2, 5). If this is not possible, and in emergency scenarios, patients should be given Pneumovax, the meningococcal ACWY vaccine (Menveo) and the meningococcal group B vaccine (Bexsero) two weeks post-surgery. A second dose of Bexsero should be given one month after this. Patients should have a booster dose of Pneumovax every five years and the Influenza vaccine yearly. Patients should receive intravenous benzylpenicillin or clarithromycin twice a day until the patient can take oral medication. This can be switched to phenoxymethylpenicillin twice a day or erythromycin twice a day. This should continue for two years or lifelong if they are in the ‘at risk’ group which includes; over 50 years old or under 16 years old, history of previous invasive pneumococcal disease and patients previously treated for haematological malignancy.

Results
88 patients underwent a splenectomy between January 2020 and April 2022. 3% of patients had emergency surgery; the rest were elective cases. Indications for splenectomy included pancreatic cancer, intraductal papillary mucinous neoplasm (IPMN), splenic B cell lymphoma, pancreatitis, gastric varices, metastatic ovarian cancer and metastatic renal carcinoma. 21% of patients did not receive Pneumovax and 22% of patients did not receive Bexsero two weeks post-surgery. 23% of patients did not receive ACWY and 34% of patients did not receive the second dose of Bexsero 4 weeks post discharge. 30% of patients did not receive their yearly Influenza vaccination. Overall, 21% of patients received no vaccinations. 1% of patients did not receive prophylactic antibiotics on discharge. 39% of patients’ discharge paperwork did not have appropriate documentation about when vaccinations needed to be administered.

Conclusions
Compliance rates of vaccinations and antimicrobial prophylaxis should be 100% to prevent overwhelming post splenectomy infection. Data collection on patients who do not have a CHIE record proved difficult. While collecting data, it was noted that there has been guideline change between 2020 and 2021; In 2020, the ACWY vaccination was recommended to be administered 4 weeks post splenectomy. In 2021, this changed to 2 weeks later. In 2021, the requirement for the Hib vaccination was removed.
A recurring issue during the audit process was a lack of documentation in patient discharge summaries. Whilst there are a proportion of patients who have not received their post-splenectomy vaccinations, it is reassuring to note that none of these patients had subsequent admissions to hospital with overwhelming infections based on their CHARTs records.
We have created a proforma that can be brought up on CHARTs during follow up appointments for documentation of compliance with vaccinations. GPs can be easily contacted about missing vaccinations. We also recommended that all discharge paperwork have clear documentation of when vaccinations should be administered and that a re-audit should be done in 2023.