Perioperative Acute Kidney Injury: An Under-Recognized Problem

The incidence of perioperative acute kidney injury (AKI) is more common than previously recognized, especially in high-risk patients undergoing higher risk procedures. The growing number of patients who develop perioperative AKI is related, in part, to the aging population and increase in the number of individuals with chronic comorbidities, particularly those with premorbid chronic kidney disease. Despite the acceptance of standardization in the definition of AKI, clinicians routinely underdiagnose it and fail to appreciate that it is associated with considerable morbidity and mortality. Unfortunately, few, if any, preemptive therapies have proven effective in preventing AKI. Timely diagnostic methods using evolving biomarkers raises the prospect of detection of kidney damage before the onset of irreversible loss of function, but remain under investigation. Clear evidence supporting any therapeutic intervention except renal replacement therapy remains elusive. Renal replacement therapy is indicated for select patients with progressive AKI; however, the ideal timing, method, and application of it remain under debate. It is fundamental to identify patients at risk for AKI. The Kidney Disease: Improving Global Outcomes guidelines suggest preventive strategies that include avoidance of nephrotoxic agents and hyperglycemia, optimization of hemodynamics, restoration of the circulating volume, and institution of functional hemodynamic monitoring. Clear evidence in support of this approach, however, is lacking. Recently, the perioperative administration of dexmedetomidine and the provision of remote ischemic preconditioning have been studied to potentially limit the development of perioperative AKI. This review discusses accepted standard definitions of AKI, highlights associated risk factors for its development, and provides an overview of its epidemiology and pathology. It emphasizes potential preventive strategies, the possible role of emerging biomarkers in defining its presence more expeditiously before irreversible injury, and current recommended guidelines and therapeutic approaches. The ultimate goal of this article is to bring to the attention of clinicians the seriousness of this potentially preventable or modifiable perioperative complication.