Fluid responsiveness assessment is a major issue in intensive care. Since fewer fluid responsiveness tests can be used children, fluid expansion prescriptions are often based on professional practices due to the absence of guidelines. This observational, cross-sectional, multicentric study is an evaluation of professional practices regarding fluid expansions in pediatric intensive care units. The main objective will be to describe the proportion of fluid expansions that are administered following an assessment of fluid responsiveness.

Fluid expansion is the cornerstone of acute circulatory failure treatment. Although this therapy drastically reduced mortality, several studies in recent years have highlighted the adverse effects of excessive fluid expansion (leading to fluid overload). Currently, the search for indicators to predict fluid responsiveness is a major issue in intensive care units (ICU). These indicators are based on Franck-Starling's law: if small changes in preload lead to an increase in cardiac output, then fluid responsiveness can be expected. This assessment is necessary but must be as simple as possible in an emergency setting such as ICU. Although several fluid responsiveness tests are available in adults, they are underused in current practice. In children, the only validated indicator (respiratory variability of peak aortic velocity) can only be used in the absence of any spontaneous respiratory movement, a rare situation in practice. Thus, fluid expansion prescriptions in pediatric ICU (PICU) are based on professional practices that are often heterogeneous due to the absence of evidence-based guidelines. An evaluation of professional practices is a first step towards standardizing practices.

This study is an evaluation of professional practices regarding fluid expansion in PICU. The main objective will be to describe the proportion of fluid expansions that are administered following an assessment of fluid responsiveness.

We will conduct an observational, cross-sectional, multicentric study in French PICU. Data will be collected retrospectively, after fluid expansion administration, by the prescribing physician through a electronic CRF (RedCAP). These data will be collected from standard monitoring and/or from the patient's medical record. Data will therefore only be collected at a single point in time.

Inclusion Criteria:

• Age less than or equal to 15 years old
• Hospitalization in a pediatric intensive care unit
• Prescription by the attending physician of a fluid expansion in order to increase cardiac output and restore the patient's circulatory function, which the physician has judged to be impaired. Fluid expansion is defined as a rapid intravenous infusion (<30min) of a high volume (>10ml/kg or 250ml) of an isotonic crystalloid solution, albumin, or fresh frozen plasma. The decision to administer a fluid expansion and the type of fluid administered are left to the discretion of the physician (current practice).

Exclusion Criteria:

• Patient less than 37 weeks' corrected gestational age
• Univentricular circulatory physiology
• Mechanical circulatory support
• Opposition of the patient or his/her parents or legal guardians to data collection

Fluid expansion prescriptions in pediatric ICU (PICU)