Effects of Meropenem on Patients with Ventilator-Induced Pneumonia in Intensive Care Unit

Ventilator-associated pneumonia (VAP) is a relatively common disorder that is associated with higher mortality than other nosocomial pneumonias. Various antibiotics, including meropenem are used in treatment of this disease. The present study was designed to evaluate the population pharmacodynamics of meropenem.

This cross-sectional study was carried out in 57 patients with VAP. All patients received iv infusion of meropenem (1 g) every eight hours and the pharmacokinetic parameters obtained from these patients were used in a parallel study to simulate the duration of plasma concentration above the minimum inhibitory concentration (MIC). Standard microbiological tests were used on tracheal aspiration samples to identify the microbial etiology of VAP, and MIC against bacterial infection was determined by E-test. Finally, the time when the drug concentration was higher than the MIC between two consecutive administrations was calculated.

The prevalence of VAP pathogens was similar to the results of other studies. In 90% of patients, the MIC of meropenem against VAP-producing microbes was more than 32 µg/ml (ratio of free drug concentration above MIC) indicating resistance to treatment and only in four patients was less than 0.064 µg/ml, which indicates sensitivity to treatment.

Due to the high prevalence of meropenem resistance among VAP-producing pathogens, meropenem administration is recommended after antibiogram evaluation.