Do not drown the patient: appropriate fluid management in critical illness

Abstract

Administering intravenous fluids to support the circulation in critically ill patients has been a mainstay of emergency medicine and critical care for decades, especially (but not exclusively) in patients with distributive or hypovolemic shock. However, in recent years, this automatic use of large fluid volumes is beginning to be questioned. Analysis from several large trials in severe sepsis and/or acute respiratory distress syndrome have shown independent links between volumes of fluid administered and outcome; conservative fluid strategies have also been associated with lower mortality in trauma patients. In addition, it is becoming ever more clear that central venous pressure, which is often used to guide fluid administration, is a completely unreliable parameter of volume status or fluid responsiveness. Furthermore, 2 recently published large multicenter trials (ARISE and ProCESS) have discredited the “early goal-directed therapy” approach, which used prespecified targets of central venous pressure and venous saturation to guide fluid and vasopressor administration. This article discusses the risks of “iatrogenic submersion” and strategies to avoid this risk while still giving our patients the fluids they need. The key lies in combining good clinical judgement, awareness of the potential harm from excessive fluid use, restraint in reflexive administration of fluids, and use of data from sophisticated monitoring tools such as echocardiography and transpulmonary thermodilution. Use of smaller volumes to perform fluid challenges, monitoring of extravascular lung water, earlier use of norepinephrine, and other strategies can help further reduce morbidity and mortality from severe sepsis.