Initial dosing regimen of vancomycin to achieve early therapeutic plasma concentration in critically ill patients with MRSA infection based on APACHE II score

Abstract

It is essential to assure the efficacy of antimicrobials at the initial phase of therapy. However, increasing the volume of distribution (Vd) of hydrophilic antimicrobials in critically ill patients leads to reduced antimicrobial concentration in plasma and tissue, which may adversely affect the efficacy of that therapy. The aim of the present study was to establish a theoretical methodology for setting an appropriate level for initial vancomycin therapy in individual patients based on Acute Physiology and Chronic Health Evaluation (APACHE) II score. We obtained data from patients who received intravenous vancomycin for a suspected or definitively diagnosed Gram-positive bacterial infection within 72 h after admission to the intensive care unit. The Vd and elimination half-life (t 1/2) of vancomycin values were calculated using the Bayesian method, and we investigated the relationship between them and APACHE II score. There were significant correlations between APACHE II scores and Vd/actual body weight (ABW), as well as t 1/2 (r = 0.58, p < 0.05 and r = 0.74, p < 0.01, respectively). Our results suggested that the Vd and t 1/2 of vancomycin could be estimated using the following regression equations using APACHE II score.[Formula: see text] [Formula: see text]We found that APACHE II score was a useful index for predicting the Vd and t 1/2 of vancomycin, and used that to establish an initial vancomycin dosing regimen comprised of initial dose and administration interval for individual patients.

Individualized Pharmacokinetic Dosing of Vancomycin Reduces Time to Therapeutic Trough Concentrations in Critically Ill Patients

“…The vancomycin t 1/2 and V observed in our patients were highly variable and consistent with previously published data . The disparity in t 1/2 and V was not surprising because 30% of the patients had AKI at baseline and 44% had a body mass index ≥30 kg/m 2 .…”

“…The vancomycin t 1/2 and V observed in our patients were highly variable and consistent with previously published data. 14,22,23 The disparity in t 1/2 and V was not surprising because 30% of the patients had AKI at baseline and 44% had a body mass index ࣙ30 kg/m 2 . We believe these findings limit the utility of dosing nomograms in the ICU setting because they rely on the Cockcroft-Gault equation, which overestimates renal function during the early stages of AKI.…”

SOFA score is superior to APACHE-II score in predicting the prognosis of critically ill patients with acute kidney injury undergoing continuous renal replacement therapy

“…However, the APACHE-II score was not associated with the prognosis of patients with AKI undergoing CRRT. APACHE-II score is one of the most used predictive scoring systems for critically ill patients and has been widely used in predicting prognosis [21][22][23]. However, several studies report conflicting predictive accuracy results associated with the APACHE-II score in critically ill patients.…”

Initial Serum C-reactive Protein Level as a Predictor of Increasing Serum Vancomycin Concentration During Treatment

“…Because leakage from capillaries to body cavities increases during inflammation, the volume of distribution of hydrophilic antimicrobials increases in critically ill patients, including patients with sepsis. [16][17][18] In particular, Imaura et al 17 reported that the volume of distribution of VCM was correlated with the Acute Physiology and Chronic Health Evaluation II score, a measure of disease severity associated with inflammatory cytokines, such as tumor necrosis factor-a (TNF-a) and interleukin-6 (IL-6). This is consistent with our finding that CRP is an independent influencing variable.…”