Although the pharmacokinetics of Caspofungin has been studied in healthy subjects and patients, only a few studies have been performed in critically-ill patients. In these patients several factors, including sepsis, shock, increased distribution volume, hepatic dysfunction and hypoalbuminemia may result in dramatic changes in antibiotic concentrations and pharmacokinetics. Caspofungin pharmacokinetic data is scarce and are results mainly from case series or animal studies. Thus, studies performed so far show Caspofungin trough concentrations either decreased, similar to usual value in non-critically ill patients or increased. One of these studies suggested that body weight and hypoalbuminemia may be the main factors associated with Caspofungin pharmacokinetic variability. Pharmacokinetic parameters of caspofungin in pigs with hypovolemic shock suggested the peripheral volume of distribution of caspofungin and intercompartmental clearance to be higher than in healthy animals. These results are however preliminary and cannot be extrapolated suggesting further clinical studies in human to be needed.

The primary objective of this study is to assess Caspofungin trough concentrations and pharmacokinetics in critically-ill patients requiring vasopressors.

Inclusion Criteria:

• Adult patients (age > 18 y.o)
• Either preemptive, empirical or curative prescription of Caspofungin by one of the ICUs' attending physician
• Requiring vasopressors
• Admission in one of the participating ICUs.

Exclusion Criteria:

• Pregnancy
• Lack of affiliation to the National Medical Insurance
• Previous inclusion in the study
• Inclusion in a concomitant study that may interact with the current study