The importance of pharmacokinetic consultation of cefepime treatment for Pseudomonas aeruginosa bacteremia: a case report of severe thermal burn injury

The patient is a 54-year-old man with severe thermal burn injury involving 45.5% of the total body-surface area, complicated with bacteremia caused by Pseudomonas aeruginosa with a cefepime MIC of 8 µg/ml. The plasma concentrations of cefepime 1 g every 6 h measured by validated high performance liquid chromatography were 25.8 µg/ml at 1 h and 6.28 µg/ml at 5 h after infusion, and 3.9 µg/ml before the infusion, when creatinine clearance was increased to 136 ml/min by vigorous fluid replacement. The pharmacokinetic–pharmacodynamic analyses in the one-compartment model with use of the Sawchuk–Zaske method revealed marked increase in the volume of distribution (28.9 l), total clearance (10.7 l/h), and shortening of plasma half- life (1.79 h) of cefepime, with time >MIC and 24-h area under the concentration–time-curve being 58% and 358, respectively. These pharmacokinetic parameters of cefepime quantified in the patient estimated a time >MIC of 87% if administered every 4 h. P. aeruginosa, however, was successfully eradicated without revision of the dosing regimen of cefepime. Decrease in creatinine clearance by correction of the fluid imbalance and wound closure by skin graft surgery likely contributed to the restoration of fluid shift, resulting in normal disposition of cefepime and favorable clinical outcome of the patient.