Improving adherence to and effectiveness of a vancomycin continuous infusion protocol, a pilot quality improvement project

Abstract

Abstract Introduction Vancomycin treats serious Gram-positive infections such as methicillin-resistant Staphylococcus aureus. In St George’s University Hospital’s (SGH) intensive care unit (ICU) settings, vancomycin is administered by continuous infusion. Steady-state serum concentrations are measured daily with a 20-25 mg/L target. Non-therapeutic concentrations are associated with adverse drug reactions/prolonged length of stay.1 A SGH service-evaluation conducted across all three ICUs, revealed variable adherence to/effectiveness of its vancomycin prescribing/administration/monitoring protocol.2 Consequently, multifaceted interventions were devised using the Institute-for-Healthcare-Improvement’s model Plan-Do-Study-Act (PDSA) cycles and piloted on General ICU (GICU). Aim (1) To improve adherence to/effectiveness of the vancomycin protocol. (2) To ascertain administration accuracy of paper-fluid-balance-charts compared to the electronic-prescribing-and-medicines-administration (ePMA) system to assist with identifying per protocol treated patients. Methods PDSA Cycle-1 was conducted over a 9-month period (09/2021-05/2021) in which a mix of system/person-focused interventions were implemented. Protocol dosing2 was revised, introducing a >90kg patient 2g loading dose, renal-function category revision and increased maintenance dose for creatinine clearance (CLCR) >90ml/min. Protocol accessibility was increased via integration into an ePMA prescribing interface, plus CliniBee/Microguide apps. Educational slides on relevant protocol aspects were incorporated into medical/nursing induction training. Data relating to vancomycin prescribing/administration/monitoring for all non-renal replacement patients was extracted retrospectively from the ePMA system between 09/2021-05/2022. This data was compared to baseline GICU data (07/2020-07/2021).2 The project and associated interventions were approved by Trust Clinical Governance and Audit Teams. Data was collected by pharmacists directly involved in patient’s care and stored/analysed on the Trust’s secure server in line with Data Protection Act principles. Due to local generalisability, ethics approval wasn’t required. Results Compared to baseline, the proportion of patients receiving per protocol prescribing/administration of loading/maintenance doses with daily monitoring, nearly doubled (39% (7/18) to 68% (15/22)). 48-hour vancomycin serum concentrations in all patients increased therapeutically by 21% (3/9 to 7/13). In per protocol treated patients, concentrations increased 15% (2/7 to 4/9) therapeutically, decreased 21% (3/7 to 2/9) supra-therapeutically and increased 4% (2/7 to 3/9) sub-therapeutically. Supra-therapeutic concentrations were associated with CLCR<50ml/min. Sub-therapeutic concentrations were associated with CLCR>90ml/min and obesity. Compared to the ePMA system, there was 36% (8/22) less paper-fluid-balance-charts recording both loading/maintenance doses. Maintenance dose administration times in 9% (2/22) of cases differed by >60 minutes. Discussion/Conclusion Staff-turnover periods were associated with decreased protocol compliance. Observations suggest further education is required around prescribing/administration of standardised infusion bags for maintenance dosing. Pharmacist integration into daily Microbiology ward rounds may increase protocol compliance. Higher 20mg/kg loading doses for obese patients and maintenance dose revision should be considered to reduce non-therapeutic concentrations.3 Limitations include heterogenous/small sample sizes due to data paucity and vancomycin requirement. This can be addressed by involving all ICU’s in PDSA Cycle-2. Due to disparities, both the ePMA system and paper-fluid-balance-charts should be used to identify protocol adherence. Utilisation of digital-infusion-pump data to quantify administration accuracy may offer a promising solution. Piloted multifaceted interventions were successful at improving adherence to/effectiveness of the vancomycin protocol. Findings have informed further interventions and data capture methods for PDSA Cycle-2 implementation across all ICUs.