Assessment of urine partial oxygen pressure to predict postoperative acute kidney injury in major surgical patients

Urine partial oxygen pressure (PuO2) was monitored in postoperative intensive care unit (ICU) patients to verify if an earlier diagnosis of acute kidney injury (AKI) is possible. Fifty-nine patients who were admitted to the ICU after surgery for at least 48 hours at Kawasaki Medical Center between January 2019 and June 2020 were assessed for AKI using the Kidney Disease: Improving Global Outcome (KDIGO) criteria. The AKI group had 15 patients while the non-AKI group had 44 cases. The PuO2 of each group showed no significant difference. Arterial partial oxygen pressure (PaO2) was measured concurrently with PuO2. When the ratio of PuO2 to PaO2 (PuO2 / PaO2) from each group was compared, the AKI group had a significantly higher ratio just 2 hours after admission to the ICU. Reduced oxygen consumption in the renal medulla may be a possible cause of AKI in those patients. Thus, measuring the PuO2 / PaO2 ratio in postoperative patients 2 hours after ICU admission could be useful to predict AKI earlier than is currently done