Fluid administration in critically ill patients with acute kidney injury.

Physiologic end points for fluid resuscitation in septic shock patients with acute kidney injury (AKI) have been undertaken in randomized studies using the Early Goal-Directed Therapy (EGDT) approach. These studies have demonstrated a beneficial effect on in-hospital mortality with EGDT. The Saline versus Albumin Fluid Evaluation (SAFE) randomized study in critically ill patients demonstrated no difference in survival when saline versus albumin solutions were used for resuscitation. However, a benefit of albumin has been demonstrated in a randomized study on renal function and survival in cirrhotic patients with spontaneous bacterial periotonitis. On the other hand, recent observational studies have shown a correlation between fluid overload and mortality in AKI patients whether or not they necessitated dialysis. Moreover, the Adult Respiratory Distress Syndrome (ARDS) network performed a randomized study in critically ill patients to compare liberal versus conservative fluid administration. The liberal fluid administration group exhibited worse pulmonary function and no protection of renal function. Constancy of central venous pressure (CVP) measurements in the 12-mmHg range were observed in the liberal fluid group despite a mean increase in positive fluid balance of 7 L, thus suggesting increased interstitial fluid accumulation leading to pulmonary congestion. The review presented here discusses these various aspects of fluid administration in critically ill patients, particularly those with AKI, and indicates the potential deleterious effects of fluid overload on lung, heart, and kidney function that could contribute to increased mortality.