Urine Oxygen Partial Pressure Monitoring to Assess Acute Kidney Injury Risk

Acute kidney injury (AKI) is a common complication associated with cardiac surgery. AKI is associated with increased hospital costs, hospital length of stay (LOS), and mortality risk. The KDIGO criteria are the most common diagnostic criteria and are based on changes in serum creatinine and decreased urine output. While useful for estimating renal function, serum creatinine and urine output are not renal specific, can be influenced by factors other than kidney injury and lead to delayed AKI diagnosis which precludes injury prevention. To overcome these limitations, researchers have primarily focused on chemical biomarkers. The use of these tests is limited by time, cost, and effectiveness. Thus, there is a need for a rapid biomarker that is physiologically linked to the development of AKI and is easy to interpret. Preliminary studies have shown that urine oxygen partial pressure (PuO2) may be a physiological biomarker of AKI. The aim of this research was to understand how frequently reliable PuO2 measurements can be acquired with a novel device and whether PuO2 is in fact an indicator of AKI. First, this study found that patients who develop AKI have lower mean PuO2 during cardiac surgery. Secondly, the study showed it is possible to acquire reliable PuO2 data at least every 3 minutes in most patients. These results warrant further research to understand the role PuO2 may play in improving AKI diagnosis. In conclusion, PuO2 monitoring could potentially improve AKI risk monitoring in cardiac surgery and even austere settings such as during space travel