The main objective of this study is to describe the pharmacokinetics of the prescribed echinocandins for septic shock with secondary peritonitis for which intra-abdominal fungal infection is suspected or proven.

The secondary objectives of this study are:

• Determine whether the current recommended doses of caspofungin achieve the Pharmacokinetic/Pharmacodynamic (PK/PD) target for this molecule.
• Determine whether the current recommended doses of micafungin achieve the PK / PD target for this molecule
• Describe the peritoneal concentrations of echinocandins in secondary peritonitis complicated with septic shock
• Identify via modeling PK / PD parameters and based on monte Carlo simulations the optimal dosing regimen for caspofungin and micafungin in this population

Inclusion Criteria:

• The emergency inclusion procedure was correctly applied according to French law (signature of consent form by a patient-designated trusted person or a family member, or a medical decision to proceed with patient inclusion if the latter two persons are unavailable) ---- OR ---- signature of the consent form by the patient
• The patient must be insured or beneficiary of a health insurance plan
• The patient is 18 years of age or older
• The patient has beed admitted to the ICU for septic shock accompanying secondary peritonitis
• Patient requiring antifungal treatment via echinocandins (caspofungin or micafungin)
• A venous or arterial access for blood sampling is already in place for routine care

Exclusion Criteria:

• The patient is participating in an interventional study that may affect the results of the present study, or has participated in such a study within the past 3 months
• The patient is under judicial protection, or is an adult under guardianship
• The patient is pregnant, parturient or breastfeeding
• Moribund patient
• Known positive serology for human immunodeficiency virus (HIV)
• Known positive serology for hepatitis C
• Known diagnosis for tuberculosis