Fluid management is a core aspect of critical care, guiding decisions around the type, timing, and amount of fluid therapy. The administration of intravenous fluids aims to restore and maintain tissue perfusion, replace overt losses, and serve as a carrier for drug delivery. While fluid administration is often emphasised during the resuscitation phase, growing evidence highlights the risks associated with sustained positive fluid balance, including tissue oedema, organ dysfunction, and increased mortality. A clear understanding of the pathophysiological mechanisms underlying fluid homeostasis can support decision-making during fluid de-escalation. Recognising the role of the lymphatic system in interstitial fluid clearance, and its potential impairment during critical illness, may help guide appropriate timing and realistic expectations for fluid removal. Fluid de-escalation includes limiting fluids to daily physiological needs, and when excess fluid persists, active fluid removal using pharmacological or mechanical interventions may be required. Evidence supporting adjunctive measures, such as albumin, hypertonic saline, or compression techniques, remains limited. There is increasing interest in understanding whether treatment effects differ across patient phenotypes, and studies in patients with lung injury suggest this may also apply to fluid management strategies. In one study, hyperinflammatory patients appeared to benefit from a conservative fluid approach, while hypoinflammatory patients had worse outcomes, despite no overall difference in mortality between the strategies. These findings highlight the potential value of phenotype-guided fluid strategies. Although fluid de-escalation is clinically important, evidence on the optimal timing, volume, and duration of fluid removal remains limited. While individualized ICU care often incorporates real-time hemodynamic variables, current strategies rely heavily on clinical judgment in the absence of standardized criteria. It also remains unclear whether a degree of permissive hemodynamic instability might be acceptable for preventing or reversing fluid overload. Ultimately, weaning from fluid support should be seen as a continuous, individualized process. Ward round discussions should explicitly name fluid overload as a working diagnosis and recognise persistent fluid accumulation or difficulty in removal as a barrier to recovery, comparable to difficult weaning from mechanical ventilation or ICU-acquired weakness.
Bircher et al. (Thu,) studied this question.