Intraoperative arterial blood pressure waveform variation predicts short-term acute kidney injury after cardiac surgery

Background: Arterial blood pressure (ABP) waveform presents the dynamic condition of cardiac surgery. Variation in waveform morphology (VarM) may reflect the complex interactions of cardiovascular regulatory mechanisms. We investigated the association between VarM and the development of acute kidney injury (AKI) following cardiac surgery. Methods: In this prospective observational single-cohort study, 101 patients undergoing elective cardiac surgery involving cardiopulmonary bypass (CPB) were enrolled. VarM was quantified from consecutive ABP waveform pulses. Postoperative AKI was defined using serum creatinine levels according to the KDIGO criteria. Results: After weaning from CPB, AKI group showed a lower VarM index and a lower trend. In the presence of baseline renal function, EuroSCORE, and CPB duration, VarM provided additional predictive value for identifying patients at risk of AKI (AUROC: 0.775 vs. 0.762). Conclusions: VarM derived from the ABP waveform following CPB is associated with the incidence of short-term postoperative AKI.