Heart Care Info - Heart Disease Prevention & Treatment

The Acute Kidney Injury to Chronic Kidney Disease Continuum: Comment on" The Magnitude of Acute Serum Creatinine Increase After Cardiac Surgery and the Risk ...

N Pannu, B Hemmelgarn - Archives of Internal Medicine, 2011 - Am Med Assoc The development of postoperative acute kidney injury (AKI) has been identified as the strongest risk factor for death in patients undergoing cardiac surgery. 1 Patients requiring renal replacement therapy for postoperative AKI have mortality rates ranging from 40% to 80%, rates of ...

Changes in urinary output and serum creatinine levels remain the criterion standard for the detection of AKI. Oliguria is an insensitive indicator of AKI, and nonoliguric AKI may be overlooked if the urinary output remains adequate. Serum creatinine levels are also insensitive to acute changes in renal function7 and may be affected by factors such as age, sex, race, muscle mass, and medications8 - 9 as well as dilution in the setting of volume resuscitation. As a consequence, more sensitive definitions of AKI have evolved, incorporating relatively small changes in serum creatinine levels (0.3-5.2 mg/d L [to convert to micromoles per liter, multiply by 88.4]). Acute kidney injury defined as such is associated with high costs and adverse clinical outcomes, including excess mortality, increased length of hospital stay, and the requirement for long-term dialysis in survivors in a variety of clinically settings. This association, however, has been most powerful among patients undergoing cardiac surgery. Studies exclusively of patients who have undergone cardiac surgery show that even smaller increases in serum creatinine levels (in the range of 0-5.2 mg/d L within the first 48 hours) are associated with a 3-fold increase in 30-day mortality.3 - 4 Little is known about long-term outcomes after AKI, although a single study of AKI survivors after cardiac surgery with a 10-year follow-up period demonstrated that patients with a 50% increase in serum creatinine levels have a long-term risk of death that persists even in those who have complete renal recovery.10