Ann Thorac Surg. 2023 Jun 2:S0003-4975(23)00575-1. doi: 10.1016/j.athoracsur.2023.04.049. Online ahead of print.
ABSTRACT
BACKGROUND: Postoperative acute kidney injury (AKI) in cardiac surgery patients is multifactorial and associated with low oxygen delivery (DO2) during cardiopulmonary bypass.
METHODS: Cardiac surgical patients undergoing full cardiopulmonary bypass between 5/1/2016-12/31/2021 were included, while those on preoperative dialysis, underdoing circulatory arrest procedures, or lacking minute-to-minute physiological data were excluded. A 5-minute running average of oxygen delivery (DO2i, ml/min/m2) was calculated ([pump flow]x[hemoglobin]x1.36[hemoglobin saturation]+0.003[arterial oxygen tension]/body surface area). AKI was defined using established Kidney Disease: Improving Global Outcomes criteria. The threshold of nadir DO2i on the effect of AKI was estimated using risk-adjusted constrained broken-stick models.
RESULTS: Postoperative AKI occurred among 1,155 (29.4%) patients, with 276 (7.0%) having Stage 2-3 AKI. The median nadir DO2i was lower for those with (versus without) AKI (197.9 ml/min/m2 [166.3-233.2] versus 217.2 [184.5-252.2], p < .001) and Stage 2-3 AKI relative to Stage 1 or none (186.9 ml/min/m2 [160.1-220.5] versus 213.8 [180.4-249.4]). In risk-adjusted analyses, the estimated threshold (CI 95%) for nadir DO2i was 231.2 ml/min/m2 (173.6-288.8) for any AKI and 103.3 (68.4-138.3) for Stage 2-3 AKI.
CONCLUSIONS: Decreasing nadir DO2i was associated with an increased risk of AKI. The identified nadir DO2i thresholds suggest management and treatment of nadir DO2i during cardiopulmonary bypass may decrease a patient’s postoperative AKI risk.
PMID:37271444 | DOI:10.1016/j.athoracsur.2023.04.049