LAUSR

Recent studies suggest that intensive care unit patients treated with amikacin frequently do not attain the desired pharmacokinetic/pharmacodynamic (PK/PD) target, i.e. peak amikacin concentration (Cpeak) to minimum inhibitory concentration (MIC) ratio of ≥8, when a single dose of 15 mg/kg is used. No data are available for patients admitted to the emergency department (ED). The aim of this prospective randomised controlled study was to determine PK/PD target attainment in ED patients presenting with severe sepsis or septic shock treated with 15 mg/kg versus 25 mg/kg amikacin. Patients were randomly assigned to receive amikacin 25 mg/kg or 15 mg/kg. Amikacin Cpeak values were determined. The primary outcome was target attainment defined as Cpeak/MIC ≥ 8 both using EUCAST susceptibility breakpoints and actually documented MICs as denominator. A total of 104 patients were included. The EUCAST-based target was attained in 76% vs. 40% of patients assigned to the 25 mg/kg vs. 15 mg/kg dose groups (P <0.0001). Target attainment using actual MICs (median of 2 mg/L, documented in 48 isolated Gram-negative pathogens) was achieved in 95% vs. 94% of patients in the 25 mg/kg vs. 15 mg/kg dose groups (P = 0.969). Risk factors associated with PK/PD target failure were identified in the multivariable analysis. At least 25 mg/kg amikacin as a single dose should be used in ED patients with severe sepsis and septic shock to attain the EUCAST-based PK/PD target. However, when using local epidemiology as denominator, 15 mg/kg appears to be sufficient. [ClinicalTrials.gov ID: NCT02365272.