The Pharmacodynamics of Meropenem in Patient With Ventilator-associated Pneumonia

The study was a randomized three-way crossover study. Each subject received meropenem in three regimens at room temperature consecutively: (i) bolus injection of 1 g of meropenem over 10 min every 8 h for 24 h, (ii) 3-h infusion of 1 g of meropenem via an infusion pump at a constant flow rate every 8 h for 24 h, and(iii) 3-h infusion of 2 g of meropenem via an infusion pump at a constant flow rate every 8 h for 24 h. Clinical and laboratory data such as Age,Sex, Body weight, Electrolyte, Vital signs, APACHE II score, BUN, Cr, Blood culture will be collected. Nine patients will be enrolled in this study. After completion of the meropenem therapy for 3 days in this study, all patients will receive other sensitive antibiotics to eradicate their bacterial infections. Meropenem pharmacokinetic studies were carried out during administration of the third dose of each regimen (16 to 24 h after the start of each regimen). Blood samples (approximately 5 ml) were obtained by direct venipuncture at the following times: before (time zero) and 10 and 30 min and 1, 1.5, 2, 2.5, 3.5, 4, 4.5, 5, 6, and 8 h after the third dose of each regimen. The concentrations of meropenem were determined by reverse-phase high-performance liquid chromatography. Concentration of meropenem in plasma will be simulated in Monte Carlo technique (Computer model) to get PK/PD index (40%T\>MIC) and reported to % PTA(Probability Target Attainment) and %CFR (Cumulative Faction Response)