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The following is a summary of “High-dose colistin pharmacokinetics in critically ill patients receiving continuous renal replacement therapy,” published in the September 2024 issue of Critical Care by Pascale et al.
Colistin is used in patients critically ill undergoing continuous renal replacement therapy (CRRT), with current guidelines recommending high dosage intravenously colistimethate (CMS).
Researchers conducted a retrospective study to define the colistin pharmacokinetic/pharmacodynamic (PK/PD) profile in patients critically ill with carbapenem-resistant (CR) bacterial infections undergoing CRRT.
They examined patients admitted to 3 Intensive Care Units (ICUs) treated with colistin for at least 48 hours at a dosage of 6.75 MUI q12, following a 9 MIU loading dose (LD), and undergoing CRRT. After the 7th dose, they collected blood samples during a 24-hour time frame.
The results showed 20 patients with CR-Acinetobacter baumannii ventilator-associated pneumonia, characterized by the median Simplified Acute Physiology Score II (SAPS II) and SOFA scores were 41 [34.5–59.3] and 9 [6.7–11], respectively, 15 patients died during ICU stay and 6 recovered renal function. Median peak and trough colistin concentrations were 16.6 mcg/mL [14.8–20.6] and 3.9 mcg/mL [3.3–4.4]. Median area under the time–concentration curve (AUC0-24) and average steady-state concentration (Css,avg) was 193.9 mcg h/mL [170.6–208.6] and 8.07 mcg/mL [7.1–8.7]. The probability of target attainment of colistin pharmacodynamics according to the fAUC0-24 / Minimum inhibitory concentration (MIC) target ≥ 12 was 100% for MIC ≤ 2 mcg/mL and 85% for MIC = 4 mcg/ML, although exceeding the toxicity limit of Css,avg 3–4 mcg/mL.
They concluded that the recommended CMS dosage in patients critically ill with CR infections undergoing CRRT resulted in colistin plasmatic levels above the bacterial MIC90 but exceeded the safety Css,avg limit.
Source: annalsofintensivecare.springeropen.com/articles/10.1186/s13613-024-01384-1#Abs1
