Practice of Fluid and Vasopressor Therapy in Critically Ill Invasively Ventilated Patients (PRoFLUID)-study protocol for an international multicenter observational cohort study.

Background: The practice of intravenous fluid and vasopressor therapy in intensive care unit (ICU) patients, particularly in those who receive invasive ventilation, has been subject to change. Traditional approaches of 'early and liberal fluid administration' and 'late and restrictive vasopressor use' have been challenged, leading to recommendations for giving less fluids and earlier administration of vasopressors. Recommendations for fluid deresuscitation-active fluid removal-are absent. The global approach to fluid and vasopressor therapy in invasively ventilated patients is currently unclear. Our aim is to explore the practice of intravenous fluid and vasopressor therapy in invasively ventilated ICU patients in a study named 'Practice of Fluid and Vasopressor Therapy in Critically Ill Invasively Ventilated Patients' (PRoFLUID). Methods: PRoFLUID is an international, multicenter, observational cohort study in critically ill adult patients that are invasively ventilated for more than 24 hours. The outcomes include various aspects of fluid and vasopressor therapy, urine output and cumulative fluid balances. We will also collect duration of ventilation, lengths of stay and mortality in ICU and hospital. We expect to collect granular data on fluid and vasopressor therapy in a sample of at least 2,500 patients. Discussion: PRoFLUID will provide useful insights into the practice of fluid and vasopressor therapy in invasively ventilated critically ill patients. PRoFLUID also allows us to determine whether geo-economic differences in management of intravenous fluid and vasopressor therapy exist, and allows for analyses of associations of aspects of fluid and vasopressor therapy with outcomes. Last but not least, its findings could feed sample size calculations of future randomized clinical trials of fluid and vasopressor therapy. In conclusion, PRoFLUID will collect data on fluid and vasopressor therapy in invasively ventilated ICU patients worldwide, providing insights that will guide future clinical decisions and randomized trial designs. Trial Registration: ClinicalTrials.gov NCT05968066. Registered on August 1, 2023. Keywords: Intensive care; invasive ventilation; fluid therapy; fluid management; vasopressor.