The Relationship Between Renal Function Early Recovery Status And Poor Prognosis In Patients With Acute Respiratory Distress Syndrome Complicated With Acute Kidney Injury

Background:Acute kidney injury(AKI)is a common complication of hospitalized patients.AKI often occurs in critically ill patients with multiple diseases and can lead to a variety of adverse outcomes.The kidney is one of the most common extrapulmonary organ injuries caused by acute respiratory distress syndrome(ARDS).Studies have found that the incidence of AKI in ARDS patients can reach 29.5-68.3%,and the occurrence of AKI in ARDS patients also predicts worse clinical outcomes.The mortality rate of patients with ARDS complicated with AKI is twice as high as that of patients with ARDS alone.More and more studies have shown that the early recovery status of renal function after AKI can affect the prognosis of patients with AKI.It has been found in patients with AKI with different causes whose renal function early unrecovered group have a worse prognosis compared with non-AKI patients and patients with AKI whose renal function recovers in a short period of time.However,the relationship between renal function early recovery status and poor prognosis in patients with ARDS complicated with AKI is not clear.Objective:To study the relationship between renal function early recovery status and poor prognosis in patients with ARDS complicated with AKI,and further explore the influence factors of renal function early unrecovered in patients with ARDS complicated with AKI.Methods:Retrospective analysis was performed on patients with ARDS complicated with AKI admitted to the intensive care unit(ICU)of Henan Provincial People’s Hospital from January 2018 to October 2022.According to whether renal function recovered within 7 days after the diagnosis of AKI,patients were divided into renal function early recovery group and renal function early unrecovered group.Basic clinical data of the two groups were collected,including the combined underlying diseases,the origin of ARDS(pulmonary or non-pulmonary),whether there is a combination of disturbance of consciousness within 24 hours of ICU admission,the worst value of biochemical indicators within 24 hours of ICU admission,whether vasopressors were used within 24 hours of ICU admission and whether invasive mechanical ventilation was performed within 24 hours of ICU admission.The stage of AKI was determined according to the change of blood creatinine value within 7 days after the diagnosis of AKI,and AKI stage 2 and AKI stage 3 were collectively referred to as severe AKI.The outcome was death within 28 days and 90 days after the diagnosis of AKI.Survival data were analyzed by the Kaplan-Meier survival analysis method,and the Log-Rank test was used to compare the differences between the two groups.Multivariate COX regression analysis was used to investigate the correlation between renal function early recovery status and death within 28 days and 90 days in patients with ARDS complicated with AKI.Receiver operating characteristic(ROC)curve was used to evaluate the predictive value of joint predictors which combine renal function early recovery status with other influencing factors to predict 28 days of death and 90 days of death in patients with ARDS complicated with AKI.To further validate the sensitivity of the results,patients who died within 7 days of the diagnosis of AKI were excluded for subgroup analysis.Multivariate Logistic regression analysis was used to study the independent influencing factors of renal function early unrecovered in patients with ARDS complicated with AKI.Result:1.General clinical features:265 patients with ARDS complicated with AKI were included,with a median age of 68.00(54.00,75.00)years old and 179 males(67.5%),167 patients with severe AKI(63.0%),106 patients(40.0%)in the renal function early recovery group and 159 patients(60.0%)in the renal function early unrecovered group.By day 28 of diagnosis of AKI,154 patients(58.1%)had died.By day 90 of diagnosis of AKI,183 patients(69.1%)had died.2.Comparison of basic data of renal function early recovery group and renal function early unrecovered group:Compared with renal function early recovery group,age,proportion of combined hypertension,proportion of combined coronary heart disease,acute physiology and chronic health evaluation scoring system Ⅱ(APACHEII),proportion of severe AKI,white blood cell count,neutrophil count,blood urea and fibrinogen of renal function early unrecovered group were all higher(P<0.05),while arterial partial pressure of oxygen,arterial oxygen saturation,albumin and estimated glomerular filtration rate(eGFR)of renal function early unrecovered group were all lower(P<0.05).In indicators of poor prognosis,compared with renal function early recovery group,the proportion of death within 28 days and 90 days after diagnosed AKI and the number of organ failure at discharge was more in renal function early unrecovered group(P<0.05),while there was no statistical significance between ICU stay time and invasive mechanical ventilation time between the two groups(P>0.05).3.Survival analysis:Kaplan-Meier curve showed that the 28-day cumulative survival rate(χ2=33.433,P<0.001)and 90-day cumulative survival rate(χ2=57.443,P<0.001)of patients with ARDS complicated with AKI were higher in the group with renal function early recovery than in the group with renal function early unrecovered.4.The relationship between renal function early recovery status and death within 28 days in patients with ARDS complicated with AKI:Multivariate COX regression analysis showed that renal function early unrecovered(HR=1.936,95%CI 1.238～3.027,P=0.004)was an independent risk factor for death within 28 days in patients with ARDS complicated with AKI.The AUC value of the combined renal function early recovery status and other independent factors of 28-day death predict patients death within 28 days with ARDS complicated with AKI was 0.775,which was higher than that of the combined predictor of other independent factors of 28-day death without renal function early recovery status(P<0.05).Patients who died within 7 days after the diagnosis of AKI were excluded for subgroup analysis,and renal function early unrecovered(HR=1.737,95%CI 1.038～2.907,P=0.036)was an independent risk factor for death within 28 days in patients with ARDS complicated with AKI.5.The relationship between renal function early recovery status and death within 90 days in patients with ARDS complicated with AKI:Multivariate COX regression analysis showed that renal function early unrecovered(HR=2.492,95%CI 1.640～3.785.P<0.001)was an independent risk factor for death within 90 days in patients with ARDS complicated with AKI.The AUC value of the combined renal function early recovery status and other independent factors of 90-day death predict patients death within 90 days with ARDS complicated with AKI was 0.813,which was higher than that of the combined predictor of other independent factors of 90-day death without renal function early recovery status(P<0.05).Patients who died within 7 days after the diagnosis of AKI were excluded for subgroup analysis,and renal function early unrecovered(HR=2.412,95%CI 1.504～3.867.P<0.001)was an independent risk factor for death within 90 days in patients with ARDS complicated with AKI.6.The influencing factors of renal function early unrecovered in patients with ARDS complicated with AKI:Multivariate logistic regression analysis showed that the risk factors of aging(OR=1.047,95%CI 1.021～1.074,P<0.001),combined hypertension(OR=3.005,95%CI 1.446～6.244,P=0.003),severe AKI(OR=10.326,95%CI 5.145～20.722,P<0.001),and fibrinogen increased(OR=1.211,95%CI 1.042～1.406,P=0.012)were independent risk factors for renal function early unrecovered in patients with ARDS complicated with AKI.Conclusions:1.Renal function early unrecovered in patients with ARDS complicated with AKI is an independent risk factor for increased risk of death within 28 days and 90 days after diagnosis of AKI,and is not affected by the severity of AKI.The joint predictors that include the renal function early recovery status can improve the predictive effectiveness of death within 28 days and 90 days in patients with ARDS complicated with AKI.Patients who died within 7 days after the diagnosis of AKI were excluded for subgroup analysis,and the results were consistent with the results of the whole cohort study.2.Aging,combined hypertension,severe AKI,and elevated fibrinogen are independent risk factors for renal function early unrecovered in patients with ARDS complicated with AKI.