Objective: This paper aimed to investigate the incidence and risk factors of postoperative acute kidney injury (AKI) in adult patients undergoing redo cardiac surgery with cardiopulmonary bypass (CPB), and explore the impact of AKI on early outcomes. Methods: A total of 116 patients undergoing redo cardiac surgery with CPB between November 2017 and May 2021 were included. Patients were divided into two groups, AKI group and non-AKI group, according to the Kidney Disease Improving Global Outcomes criteria. Perioperative variables were retrospectively collected and analyzed. Risk factors for the development of AKI were investigated by univariate and multiple logistic regression models. Clinical outcomes were also compared between the groups. Results: Postoperative AKI occurred in 63 patients (54.3%), among whom renal replacement therapy was required in 12 patients (19.0%). The mechanical ventilation time (AKI: 43.00 (19.00, 72.00) hours; non-AKI: 18.00 (15.00, 20.00) hours; p < 0.001), ICU length of stay (AKI: 4.00 (2.00, 6.00) days; non-AKI: 3.00 (2.00, 4.00) days; p = 0.010), hospital length of stay since operation (AKI: 12.00 (8.00, 18.00) days; non-AKI: 9.00 (7.00, 12.50) days; p = 0.024), dialysis (AKI: 12.00 (19.05%); non-AKI: 0 (0%); p = 0.001), reintubation (AKI: 7.00 (11.11%); non-AKI: 0 (0%); p = 0.035), and hospital mortality (AKI: 8.00 (12.70%); non-AKI: 0 (0%); p = 0.020) were all higher in the AKI group than in the non-AKI group. Multivariate analysis revealed that high aspartate aminotransferase (OR, 1.028, 95% CI, 1.003 to 1.053, p = 0.025), coronary angiogram within 2 weeks before surgery (OR, 3.209, 95% CI, 1.307 to 7.878, p = 0.011) and CPB time (OR, 1.012, 95% CI, 1.005 to 1.019, p = 0.001) were independent risk factors for postoperative AKI. Conclusions: High aspartate aminotransferase, coronary angiogram within 2 weeks before surgery and CPB time seem to be associated with an increased incidence of postoperative AKI in patients with redo cardiac surgery.

Background: Prolonged mechanical ventilation (PMV) after cardiac surgery is associated with high morbidity and mortality. Patients following redo valve surgery possess many attributes that place them at risk for PMV, yet few studies particularly focused on them. The purpose of this study was to identify perioperative variables associated with PMV in redo valve surgery. Methods: A retrospective study, including 117 patients who underwent redo valve surgery from November 2017 to September 2021, was performed. The potential perioperative risk factors for PMV were collected. PMV was defined as the need for intubation and mechanical ventilation for >24 h, after completion of the operation. The clinical data were analyzed with univariate and multivariate analyses to identify risk factors for PMV following redo valve surgery. Results: The incidence of PMV was 38.5% (N = 45). Multiple logistic regression analysis showed perioperative risk factors for PMV included advanced age (age>57 years) [odds ratio (OR) 3.043, 95% confidence interval (CI) 1.172-7.905, P = 0.022], low weight (weight ≤58 kg) (OR 2.798, 95% CI: 1.088–7.199, P = 0.033), EuroSCORE II ≥6.8% (OR 3.467, 95% CI: 1.364–8.817, P = 0.009), and VIS at 12 hours post ICU admission (VIS12) >10 (OR 5.613, 95% CI: 2.211–14.249, P < 0.001). Conclusions: In adult patients undergoing redo valve surgery, advanced age, low weight, high EuroSCORE II and a high VIS at 12 hours post-ICU admission were associated with PMV. Hemodynamic status after operation were more important than preoperative and intraoperative variables in predicting PMV.