Investigation Of Current Situation And Construction Of A Predictive Nomogram For Intensive Care Unit Acquired Weakness After Cardiopulmonary Bypass

Objective(1)To investigate the incidence and clinical characteristics of intensive care unit acquired weakness(ICU-AW)after cardiopulmonary bypass(CPB).(2)To identify the independent risk factors CPB postoperative ICU-AW,then to construct a predictive nomogram,so that the medical staff can better identify the ICU-AW.MethodA prospective observational study was conducted by including patients who were admitted to a provincial Heart Medical Center after CPB from December 2019 to November 2020.General data,clinical data,CPB data and data from ultrasound measurements of patients who met the inclusion and exclusion criteria were collected.The data collected were analyzed by descriptive analysis,t test,chi-square test,variance analysis,non-parametric test and other statistical methods according to ICU-AW ultrasonic diagnostic criteria.The collinearity diagnosis was carried out on all the variables of the result(P<0.05),the variables of variance expansion factor < 3were taken for multivariate logistic regression analysis,and the variables with statistical difference(P<0.05)were selected as independent risk factors.Based on the independent risk factors,the R software is used to construct the risk predictive nomogram,and internal verification and calibration were used to evaluate the efficacy of the nomogram.Results(1)After CPB,Cross-sectional area,Muscle layer thickness,and Pennation Angle of Muscle fibers into apononeum decreased in all patients in this study,and the decrease of Muscle was more obvious in ICU-AW group.(2)A total of 473 patients were included in this study,including 241 cases in the ICU-AW group and 232 cases in the non-ICU-AW group.The incidence of ICU-AW in patients after CPB was 50.95%.There were 253 male patients,of which 140 patients developed ICU-AW,accounting for 55.34%.Among 220 female patients,101 patients developed ICU-AW,accounting for 45.91%.(3)Among the 241 ICU-AW patients,the average age was(55.69±11.59)years,including 123 patients aged 41～60 years,accounting for the highest 51.04%.There were 119 patients with overweight of body mass index(BMI),accounting for nearly half of 49.38%.(4)In this study,most of the cardiac function grades of patients after CPB were Grade II and III,accounting for 88.4% of the total.The proportion of cardiac function grade III and IV in ICU-AW group was higher than that in non ICU-AW group.The mean left ventricular ejection fraction of patients was(63.88±8.72)%,which was lower in ICU-AW group than in non-ICU-AW group.Preoperative barthel index(BI)grade of most patients was grade III,accounting for 81.8%.Grade I in the ICU-AW group was much higher than that in the non ICU-AW group,while grade III was lower than that in the non ICU-AW group.The average CPB time of patients was129.4±59.9min,the average aortic occlusion time was(69.93±39.06)min,and the average operation time was(266.67±87.11)min.The ICU-AW group was all higher than the non ICU-AW group.The mean minimum nasal temperature of patients was(29.59 ± 3.15)℃,which was lower in the ICU-AW group than that in the non ICU-AW group.The average APACHE-II score of the patients was(22.29±3.52),which was higher in the ICU-AW group than in the non ICU-AW group.The average mechanical ventilation time,bed time and hospitalization time in ICU-AW group were higher than those in non ICU-AW group.(5)The results of univariate analysis in the ICU-AW and non ICU-AW groups showed that gender,BMI,hypertension,cardiac function grade,left ventricular ejection fraction and BI grade,calciumion,albumin,lactic acid,total bilirubin,creatinine,urea,troponin,creatine kinase-1,aortic blocking time,CPB time,operative time,minimum nasal temperature,filtrate output,intraoperative red blood cell infusion,intraoperative platelet transfusion,acute physiological and chronic health score(APACHE-II),mechanical ventilation time,renal insufficiency,bed rest time and hospitalization time were statistically significant(P<0.05).there were no significant difference in age,smoking,alcohol consumption,diabetes,hemoglobin,platelets,filtrate input,intraoperative infusion of plasma,postoperative hypoproteinemia,liver dysfunction and disease outcome between the two groups(P>0.05).(6)Multivariate logistic regression analysis showed gender-male,BMI,cardiac function grade,albumin,aortic occlusion time,operation time and APACHE-II score are independent risk factors for postoperative ICU-AW(P<0.05).(7)Construction of a nomogram based on 7 risk factors,the results showed that the concordance index(C-index)was 0.818,and the area under ROC curve was 0.818(95% CI=0.718-0.856).The calibration curve showed that the average absolute error of the standard curve and the prediction curve was 0.019.ConclusionMuscle atrophy was observed in all patients after CPB,and it was more obvious in ICU-AW patients.The incidence of ICU-AW after CPB was higher.The incidence of male patients was higher than that of women.Patients with ICU-AW after CPB generally have more serious cardiovascular diseases,deviated self-care ability,longer operation time,CPB time,and aortic occlusion time,higher APACE-II score,lower minimum nasal temperature,longer mechanical ventilation time,bed rest time and hospitalization time.Gender,BMI,cardiac function grade,albumin,aortic occlusion time,operation time,and APACHE-II score were independent risk factors for ICU-AW after CPB.Construction of a nomogram showed that the C-index was 0.818,and the error between the calibration curve and the standard curve was 0.019.It had good prediction ability and coincidence,which may be helpful for the early identification of patients at high-risk of ICU-AW.