Experience of adopting a standardised nomogram for gentamicin monitoring- an audit. Issue 2 (28th February 2020)

• Record Type: Journal Article
• Authors: Brookfield, Charlotte; Clark, Rebecca; Reddy, Suganya
• Is Part Of: Access microbiology. Volume 2:Issue 2(2020)
• Publication Date: 2020-02-28
• Subjects: Microbiology -- Periodicals; 579
• DOI: 10.1099/acmi.fis2019.po0135
• Languages: English
• ISSNs: 2516-8290

Abstract

Abstract : Background: Gentamicin, an aminoglycoside antibiotic, requires therapeutic drug monitoring to decrease the risk of nephrotoxicity and ototoxicity. We audited compliance with our dosing and monitoring guidelines since adoption of the Barnes-Jewish Nomogram for once daily 5mg/kg dosing in September 2018. Methods: We retrospectively reviewed 62 patients who received 171 gentamicin doses with 173 accompanying levels taken between 1/11/18 and 31/1/19. Results: The audit demonstrated overall poor adherence to guidelines. Only 50% of patients received the correctly calculated dose. 40% of gentamicin levels were taken between 6-14 hours resulting in a large number of uninterpretable levels requiring additional actions e.g. repeat levels. 50% of follow up doses were given in the correct time frame. For patients with normal renal function twice weekly monitoring is recommended. In all cases (n=35) where this applied levels were monitored more frequently that indicated. U&Es were regularly monitored for all patients and we did not identify any acute kidney injury. Conclusion: The Barnes-Jewish nomogram was adopted to provide a standardised evidence based monitoring system for gentamicin. However our audit demonstrates the guidance was not well executed clinically. There appeared to be a lack of appreciation and responsibility for monitoring and interpretation of levels. This resulted in erratic sampling, unnecessary levels, and delayed doses. As a result of this audit we intend to adopt a simpler trough level system based on the gentamicin SPC. Our audit demonstrates the need to evaluate service improvement implementations since theoretical benefits do not always translate in to clinical practice