Nadir oxygen delivery is associated with postoperative acute kidney injury in low-weight infants undergoing cardiopulmonary bypass

Peng Gao; Yu Jin; Peiyao Zhang; Wenting Wang; Jinxiao Hu; Jinping Liu

doi:10.3389/fcvm.2022.1020846

Nadir oxygen delivery is associated with postoperative acute kidney injury in low-weight infants undergoing cardiopulmonary bypass

Front Cardiovasc Med. 2022 Dec 16:9:1020846. doi: 10.3389/fcvm.2022.1020846. eCollection 2022.

Authors

Peng Gao¹, Yu Jin¹, Peiyao Zhang¹, Wenting Wang¹, Jinxiao Hu¹, Jinping Liu¹

Affiliation

¹ Pediatric Cardiac Surgery Center, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.

Abstract

Background: Acute kidney injury (AKI) is common after cardiac surgery with cardiopulmonary bypass (CPB) and is associated with increased mortality and morbidity. Nadir indexed oxygen delivery (DO₂i) lower than the critical threshold during CPB is a risk factor for postoperative AKI. The critical DO₂i for preventing AKI in children has not been well studied. The study aimed to explore the association between nadir DO₂i and postoperative AKI in infant cardiac surgery with CPB.

Methods: From August 2021 to July 2022, 413 low-weight infants (≤10 kg) undergoing cardiac surgery with CPB were consecutively enrolled in this prospective observational study. Nadir DO₂i was calculated during the hypothermia and rewarming phases of CPB, respectively. The association between nadir DO₂i and postoperative AKI was investigated in mild hypothermia (32-34°C) and moderate hypothermia (26-32°C).

Results: A total of 142 (38.3%) patients developed postoperative AKI. In patients undergoing mild hypothermia during CPB, nadir DO₂i in hypothermia and rewarming phases was independently associated with postoperative AKI. The cutoff values of nadir DO₂i during hypothermia and rewarming phases were 258 mL/min/m² and 281 mL/min/m², respectively. There was no significant association between nadir DO₂i and postoperative AKI in patients undergoing moderate hypothermia during CPB.

Conclusion: In low-weight infants undergoing mild hypothermia during CPB, the critical DO₂i for preventing AKI was 258 mL/min/m² in the hypothermia phase and 281 mL/min/m² for rewarming. Moreover, an individualized critical DO₂i threshold should be advocated during CPB.

Keywords: acute kidney injury; cardiac surgery; cardiopulmonary bypass; infants; oxygen delivery.