634 Achieving therapeutic vancomycin levels in neonates- a quality improvement initiative

Abstract

<h3>Aims</h3> <h3>Background</h3> Vancomycin is a commonly used antibiotic in the neonatal unit. Its efficacy correlates directly with the duration of bacterial exposure at therapeutic levels. In our unit, we found a very low proportion (29.5%) of vancomycin levels in target therapeutic levels (TTL). Continuous vancomycin infusion has been reported to achieve a higher proportion of TTL in the literature.¹ <h3>Objectives</h3> The primary objective of this quality improvement project was to improve the proportion of neonates reaching the vancomycin TTL. Our secondary objectives were to identify factors associated with high or low vancomycin levels and the incidence of renal failure in infants receiving vancomycin. <h3>Methods</h3> <h3><b>Quality Improvementinterventions</b></h3> A retrospective audit (September 2017-September 2018) was undertaken to define the baseline TTL with intermittent vancomycin dosing regimen (Pre-intervention). Following this, in July 2019, a continuous infusion vancomycin regimen using 20 mg/kg (high dose) loading followed by maintenance dose was introduced in clinical practice using quality improvement (QI) methods (post-intervention phase 1). The data was reaudited (July 2019-April 2020) and found to have higher proportion of infants had levels above TTL. Following this, continuous vancomycin loading dose was decreased to 10 mg/kg (low dose) subsequently in May 2020 (Post-intervention phase 2). The vancomycin TTL were again reaudited (May 2020-April 2021). We introduced the following key QI strategies: literature review,¹ adapting guidelines from other trusts, staff education, monthly vancomycin Kardex audits, on-site pharmacy support and development of easy access unit guidelines. <h3>Results</h3> 135 infants received vancomycin treatment during the QI period, providing 328 vancomycin samples. Seventy-two of these infants received intermittent dosing, and 63 infants received continuous vancomycin infusions. Table 1 provides the clinical and demographic factors for infants who received vancomycin during the QI period. There were 38 blood culture-positive cases. Coagulase-negative staphylococcus (74%) is the most common organism grown in blood culture, followed by E. coli (11%) and other organisms (15%). Table 2 compares vancomycin levels between all Intermittent dosing (Pre and post-intervention) versus continuous vancomycin regimens (post-intervention phase 1+2, phase 1, phase 2). Consistently continuous vancomycin levels achieved a higher proportion of vancomycin TTL (approximately 50%). We could not find any independent covariates (birth weight, birth gestation, timing of level) associated with high vancomycin level to be statistically significant in a continuous regimen. Renal toxicity (defined as creatinine&gt;100 µmol/L) was uncommon with all the dosing regimens. <h3>Conclusion</h3> Using QI methodology, we successfully integrated continuous vancomycin regime into our practice. We achieved a higher proportion of vancomycin levels in the therapeutic range using continuous vancomycin infusion. With a low loading dose (10mg/kg) continuous vancomycin infusion regime, a higher proportion of samples are achieving target therapeutic levels. Also, with the same regime, proportions of the sample below the target therapeutic range were lower, and proportions of the sample above the target range were not significantly different from intermittent dosing. <h3>Reference</h3> Vidouris M, Kumar R, Kannan Loganathan P. Do continuous vancomycin infusions achieve therapeutic target levels more often than intermittent dosing in neonates? <i>Archives of Disease in Childhood</i> 2019;<b>104</b>:1229-1231.