Peak Value of Central Venous Pressure and Acute Kidney Injury in Cardiac Patients After Cardiopulmonary Bypass Surgery

  Objective  To explore the relationship between the post-operative peak value of central venous pressure (CVPp) and the incidence of acute kidney injury (AKI) in patients who had undergone cardiopulmonary bypass surgery (CBS).

  Methods  Clinical data were retrospectively collected from 1 May 2016 to 1 May 2018 from all patients undergoing CBS in the Department of Intensive Care Medicine, Peking Union Medical College Hospital. The CVP values immediately after transfer to ICU (CVP 0h) and at 6 h(CVP 6h), and CVPp within 48 h(CVPp 48h) of transfer to ICU, the incidence of AKI after 48 h of transfer to ICU and in-hospital mortality were recorded. The receiver operating characteristic (ROC) curve was used to evaluate the clinical value of CVP-related indicators in predicting AKI after CBS and determine the optimal threshold. The risk factors for AKI and in-hospital mortality after CBS were analysed using single factor and multifactorial Logistic regression.

  Results  A total of 485 patients after CBS who met the inclusion and exclusion criteria were enrolled, with an incidence of AKI after 48 h of transfer to ICU of 25.2% (122/485) and an in-hospital mortality rate of 2.5% (12/485). The ROC curve analysis showed that the area under the curve (AUC) for CVPp 48h to predict AKI after CBS was 0.634 (95% CI: 0.577-0.692, P < 0.001), with an optimal threshold value of 14 mm Hg, sensitivity of 49.6% and specificity of 63.5%. Multifactorial logistic regression analysis showed that hypertension(OR=2.505, 95% CI: 1.581-3.969, P < 0.001), pulmonary hyperten-sion(OR=2.552, 95% CI: 1.573-4.412, P < 0.001), prolonged aortic block time(OR=1.009, 95% CI: 1.004-1.014, P=0.001), and CVPp 48h≥14 mm Hg(OR=1.613, 95% CI: 1.030-2.526, P=0.037) were independent risk factors for AKI after CBS; CVPp 48h≥14 mm Hg was an independent risk factor for in-hospital death(OR=8.044, 95% CI: 1.579-40.979, P=0.012).

  Conclusions  CVPp 48h is associated with AKI in patients who have undergone CBS. The monitoring and management of CVP might be a way to improve the prognosis of these patients.