Risk factors for acute kidney injury following coronary artery bypass graft surgery in a Chinese population and development of a prediction model

BACKGROUND Acute kidney injury(AKI)after coronary artery bypass graft(CABG)surgery is associated with significant morbidity and mortality.This retrospective study aimed to establish a risk score for postoperative AKI in a Chinese population.METHODS A total of 1138 patients undergoing CABG were collected from September 2018 to May 2020 and divided into a derivation and validation cohort.AKI was defined according to the Kidney Disease Improving Global Outcomes(KDIGO)criteria.Multivariable logistic regression analysis was used to determine the independent predictors of AKI,and the predictive ability of the model was determined using a receiver operating characteristic(ROC)curve.RESULTS The incidence of cardiac surgery–associated acute kidney injury(CSA-AKI)was 24.17%,and 0.53%of AKI patients required dialysis(AKI-D).Among the derivation cohort,multivariable logistic regression showed that age≥70 years,body mass index(BMI)≥25 kg/m2,estimated glomerular filtration rate(eGFR)≤60 mL/min per 1.73 m2,ejection fraction(EF)≤45%,use of statins,red blood cell transfusion,use of adrenaline,intra-aortic balloon pump(IABP)implantation,postoperative low cardiac output syndrome(LCOS)and reoperation for bleeding were independent predictors.The predictive model was scored from 0 to32 points with three risk categories.The AKI frequencies were as follows:0-8 points(15.9%),9-17 points(36.5%)and≥18 points(90.4%).The area under of the ROC curve was 0.730(95%CI:0.691-0.768)in the derivation cohort.The predictive index had good discrimination in the validation cohort,with an area under the curve of 0.735(95%CI:0.655-0.815).The model was well calibrated according to the Hosmer-Lemeshow test(P=0.372).CONCLUSION The performance of the prediction model was valid and accurate in predicting KDIGO-AKI after CABG surgery in Chinese patients,and could improve the early prognosis and clinical interventions.

Influence of developmental cervical stenosis on dural sac space

Background This retrospective study aimed to investigate the difference of the intra-dural reserving space for spinal cord in magnetic resonance imaging （MRI） between patients with and without developmental cervical stenosis and its clinical significance.Methods A total of 264 patients with cervical spondylotic myelopathy who had decompression surgeries were recruited.The average follow-up was 29 months.Based on their lateral radiographs,they were divided into stenosis group and non-stenosis group.On the magnetic resonance images,the ratio of the sagittal diameter of the dural sac to that of the vertebral body was measured and calculated as MRI Pavlov ratio at the mid-vertebral level on T2-weighted sagittal images from C3 to C7.The ratio of the transverse area of the spinal cord to that of the dural sac was measured and calculated as occupation ratio on T2-weighted axial images at the same levels.The MRI Pavlov ratio and occupation ratio were compared between the two groups.The stenosis group was further divided into space-reserving and non-space-reserving subgroups based on the occupation ratios; then clinical parameters were compared between the two subgroups to determine the clinical significance of the reserving space.Results The MRI Pavlov ratio of the stenosis group was significantly smaller than that of the non-stenosis group at C3-C7 （P ＜0.01）,while the occupation ratio was significantly larger only at C7 （P ＜0.05）.For the space-reserving subgroup,the postoperative recovery rate was lower （P ＜0.05）.The postoperative recovery rate was （23±6）％ in anterior approach,larger than （-23±15）％ in posterior approach （P ＜0.05）.Conclusions Developmental cervical stenosis is associated with a smaller sagittal diameter of the dural sac,but does not lead to a significant decrease in intra-dural space available for the cord.For patients with normal intra-dural space,the recovery after anterior decompression surgery was better than posterior approach.