Acute Kidney Injury in Chronic Kidney Disease

Abstract

Acute kidney injury (AKI) is an increasingly common complication of acute illness that strongly associates with increased morbidity and mortality. Growing evidence suggests that AKI is a risk factor for future development and acceleration of chronic kidney disease (CKD). Moreover, CKD patients with the most rapid progression to end-stage renal disease (ESRD) tend to have nonlinear decline in kidney function due to one or more episodes of AKI. Consequently, targeted risk reduction and preventive strategies may be beneficial for patients with CKD who experience AKI. Even among patients with CKD who do not experience AKI, evaluating for polypharmacy and nephrotoxic medications, optimizing volume status, applying prophylaxis before contrast-related procedures, and preemptively discussing long-term goals of care before hospitalization should occur, particularly among elderly patients with poor functional status. When AKI occurs in a patient with CKD, quickly identifying reversible causes and implementing treatments to rapidly restore kidney function are imperative, as patients with CKD may be more susceptible to developing irreversible tissue damage. Treatment options for established AKI remain supportive (e.g., volume-resuscitation and avoidance of nephrotoxins). However, we recommend early consultation with a nephrologist when a reversible cause is not immediately apparent, particularly for patients in whom injury is progressive and may require renal replacement therapy, or in specialized cases of AKI that may require a rapid tissue diagnosis (e.g., acute glomerulonephritis). Patients who have experienced an episode of persistent or moderate to severe AKI should be seen in follow-up a minimum of 3 months after the event to evaluate for resolution and for new onset or worsening of preexisting CKD.