The ROAD to ICU liberation: a narrative review of fluid exposure patterns for critically ill children

Abstract Fluid prescribing is a routine behavior for clinicians in the pediatric intensive care unit, and fluid exposure often occurs in a predictable pattern of high volume resuscitation before optimization of fluid balance based on data, attenuation of fluid prescribing when patients begin to improve, and diuresis to remove excess fluid accumulated while hospitalized. The evidence shaping fluid resuscitation in adults has been successfully adapted to pediatric medicine to improve morbidity and mortality in the initial phase of critical illness, but similar advances in conservative fluid prescribing strategies developed for critically ill adults have not been adopted into routine clinical practice for children. Despite knowledge of the harms associated with increased positive cumulative fluid balance, pediatric patients continue to receive non-rescuscitative fluid volumes far exceeding established hydration standards, and trials attempting to limit intake and/or augment fluid removal in children have generated mixed results in achieving the primary outcome of reduced net positive fluid balance and have not improved patient outcomes. We aim to describe the phases of fluid exposure during critical illness – resuscitation, optimization, attenuation, and diuresis – and differentiate the physiologic and practical differences shaping fluid management for adults and children.