Renal Failure in the ACS Patient: Understanding Appropriate Fluid Management and Renal Replacement Therapy

AKI is increasingly common in the ICU and is associated with significant morbidity and mortality. Several AKI definitions exist using changes in serum creatinine and urine output, although these markers have limitations. In the critically ill patient with AKI, priorities include maintaining adequate renal perfusion, precise fluid management and prevention of further renal injury. There is increasing evidence that balanced crystalloid solutions and avoidance of volume overload, especially in the maintenance and de-resuscitation phases of critical illness, are associated with improved renal and patient outcomes. There is considerable interest in the timing of RRT initiation according to individual patient need or stage of AKI; however at the present time, indications remain at the discretion of the treating physician. There is no compelling evidence to choose one dialysis modality over another, although some evidence exists for continuous therapies in specific scenarios. The right internal jugular vein is the preferred site for vascular access, and, although a majority of surgical patients are dialysed without anticoagulation, citrate is associated with less side effects and improved clearance parameters compared to heparin. There does not appear to be a benefit to increase the dose of continuous therapies above 20–25 mL/kg/h, and this is the recommended minimal delivered dose of dialysis. Looking into the future, specific biomarkers of kidney injury and imaging modalities are being developed with the goal of earlier identification of AKI. In addition, the introduction of AKI care bundles may improve processes of care and patient outcomes in the critically ill patient with AKI.