Rosalind Howe 1, Paul Cawley 1, Mark Dyke 1

Institution(s)

1. Neonatal Intensive Care Unit, Norfolk & Norwich University Hospital, UK

Introduction (include hypothesis)

Our past clinical audit has identified failure to achieve vancomycin levels in target range using intermittent infusions (2010). Other centres have demonstrated improved adherence to therapeutic targets by using continuous intravenous (IV) infusions. We have transitioned to a continuous IV infusion regimen. Aim: To audit use of our new continuous vancomycin infusion guideline against pre-specified standards & determine if compliance with blood target levels has improved when compared with historical intermittent dosing data.

Methods (include source of funding and ethical approval if required)

Prospective 7 month audit in 2017 – all gestations. Historical data provided by previous audit in 2010.

Continuous Infusion Regimen: 15mg/kg loading dose (IV –1 hour) followed by continuous infusion of between 20 to 50mg/kg/day, depending on infant’s serum creatinine & corrected gestational age. Vancomycin levels taken at 12-24 hours, with target range 15-25mg/L; Infusion rate adjusted if out of range.

Intermittent dosing regimen (2010): 15mg/kg every 24, 12 or 8 hours for infants <29, 29-35 or >35 weeks CGA respectively. Target trough range 10-15mg/L. Analysis: 2 sided Chi-Square.

Results

Within our contemporary cohort receiving a continuous IV vancomycin infusion, 100% of infants were prescribed the correct loading dose and 100% of infants had their infusion rate correctly increased if their vancomycin levels were low. A total of 61 vancomycin levels were sent for 16 infants during our prospective audit. 71% of vancomycin levels were in range (15-25 mg/L),13% were low (2.3-13.3 mg/L) and 16% were high (25.1-33.2mg/L).

Of the 16 first vancomycin levels following initiation of therapy, 10 (63%) were in target range, 1 (6%) was low and 5 (31%) were high. The proportion of first vancomycin levels in target range was significantly higher in 2017 vs 2010 [63% vs 26%, p<0.01] and the proportion of infants with sub-therapeutic levels was significantly reduced [6% vs 56%, p<0.001].

Conclusions

Our new continuous IV infusion regimen has improved compliance with blood target levels and significantly reduced sub-therapeutic levels. Continued monitoring is indicated as a significant proportion of infants still have vancomycin levels out of range.

References (include acknowledgement here if appropriate)

1. Patel A et al. Arch Dis Child 2013;98:478-479