Improving peak concentrations of a single dose regime of gentamicin in patients with sepsis in the emergency department

Objective To achieve an optimal effect in patients with sepsis at the emergency department (ED), the gentamicin peak-concentration should be sufficiently high (i.e. peak-concentration/MIC 8–10). ICU patients with sepsis often need higher gentamicin doses to achieve sufficiently high peak-concentrations. The aim of this study is to investigate which dose is needed to reach adequate peak-concentrations in patients presenting with sepsis at the ED. Methods Patients with sepsis at the ED were included from August 2015 until February 2017. Peak-concentrations were measured in blood 30 minutes after the first gentamicin dose. The study consisted of three phases. In the first phase, peak-concentrations were measured after a standard dose of 5mg/kg. In the second phase, a simulation ((peak-concentration/ actual dose) × simulated dose) was performed to determine which dose was needed to reach adequate gentamicin peak-concentrations of 16mg/L. In the third phase, peak-concentrations were measured for the best simulated dose. Results In phase one, of 86 patients who received a dose of 5mg/kg, 34 (39.5%) patients did not reach the target peak-concentration of 16mg/L, and 73 (84.9%) did not reach 20mg/L. In phase two, the simulation showed that with a dose of 7mg/kg 83 (96.5%) patients would reach peak-concentrations 16mg/L, and 67 (77.9%) of 20mg/L. In phase three, 53 patients received a dose of 7mg/kg, of whom 45 (84.9%) reached peak-concentrations of 16mg/L, and 31 (58.5%) of 20mg/L. Conclusion Patients with sepsis at the ED need higher doses of gentamicin. A dose of 7mg/kg is needed to achieve adequate peak-concentrations in the majority of patients.