Clinical Analysis Of 480 Cases With Acute Kidney Injury In Hospitalized Patients

Background and ObjectiveIn recent decades, considerable efforts have been made in basic and clinical research with ARF extensively. Although the studies have made significant progress in its pathogenesis and pathophysiology, blood purification technology has been continuously improved as well, and significantly improved the prognosis of patients with ARF from mild to moderate renal dysfunction. But mortality may come up to 90% in critically ill patients with ARF. Improving is very limited in prognosis of them.Prevention and early intervention are crucial for ARF. Proposed diagnostic criteria with AKI is beneficial to the early identification and diagnosis for timely intervention. This study retrospectively analyzes clinical data of patients with AKI and investigates epidemiological characteristics of AKI such as the constitution of causes, clinical outcomes and hospital mortality among hospitalized patients in a pandocheum, aiming to be helpful for early recognition and treatment or improving prognosis.Patients and Methods1. Study populationPatients who were admitted in the Second Hospital of Lanzhou University from January 1st 2006 to December 31st 2008. Following patients were excluded from the study cohort:patients with uremia of CRF. As a result,480 records were analyzed in the study by retrospectively analyzing occurrence of AKI in 64058 cases. 2. DefinitionsDiagnosis and stage were made according to AKI criteria, which was based on the highest SCr level or the least urine output, the baseline Cr adopted the minimum value of SCr within 48 hours during hospital stay after AKI was existed. With or without a history of chronic kidney disease,each of the patients was admitted by analyzing the changes of SCr or UV:the value of SCr was above of the normal reference range and increasing reach to 0.3mg/dl (26.5μmol/L) or 50% compared with the baseline Cr or the original level, or UV was less than 0.5ml/(kg·h) lasting more than 6 hours. excluding dehydration and decrease in UV because urinary tract obstruction or stenosis caused as SCr were in the normal reference range.The clinical outcome of patients with AKI:cured (complete renal recovery and UV was normal when leaving hospital); improved (take a turn for the better and partial renal recovery and not require dialysis); ineffective (require chronic dialysis or condition deteriorated); death3. Data collectionA retrospective clinical study was performed. Screening out of patients with AKI, then to get the information of clinical features, causes that leading to renal function impaired and clinical outcomes, and to check them for consistency verification. We classified individuals by a combination of ICD-10 diagnosis codes. All identifying information of patients were removed to protect their privacy.4. Statistical analysisContinuous variables were described as mean±standard deviation(SD) or median with interquartile range (to logarithmically transform before statistical analysis) and compared with t test or Mann-Whitney Test; One-way analysis of variance (one-way ANOVA) test or Kruskal-Wallis test when appropriate. All variables were tested for normal distribution using the Kolmogorov-Smirnov test. Categorical variables are described as proportions. Pearson Chi-square test were applied to assess categorical data associated with AKI; size of a test for univariate analysis was 0.05. To evaluate the impact of each category of patients with AKI on hospital mortality and find out the risk factors related to death of patients with AKI, we used binary logistic regression analyses,variables at P<0.05 in the univariate analysis and those considered clinically important were entered a multiple-variable logistic regression Model fit was assessed with Hosmer-Lemeshow goodness-of-fit test, P>0.05 was regarded as an acceptable model. The results of multivariate logistic regression analysis were summarized by odds ratios (OR) and respective 95% confidence interval (CI).We considered double-sided P<0.05 as statistically significant. Statistical analyses conducted using SPSS 11.0.Results1. Characteristic of patients with AKIThere were 64058 cases from January 1st 2006 to December 31st 2008 and 480 patients were admitted with the diagnostic criteria of AKI. The overall incidence of AKI was 0.75%. The proportions of male were 60.21%(289/480), mean age was 48.03 yrs (1-85years); the proportions of female were 39.79%(191/480), mean age was 48.05 yrs (1-88years). The proportions of group A were 71.04%(341/480), the proportions of group A on C were 28.96%(139/480).The proportions of oliguria were 17.71%(85/480).2. Constitution of causesCauses of prerenal and renal were main ones, but of post-renal was in the minority, which was 45.21%(217/480),24.38%(117/480), and 7.08%(34/480) respectively. Elder were in the majority,36.87%(177/480) patients were older adults aged between 60 and 88 years, and 36.25%(174/480) were between 35 and 59 years.3. Clinical outcomes194 cases were cured; 99 cases were improved; 77 cases were ineffective and 112 cases died prior to hospital discharge among 480 cases patients with AKI. In-hospital mortality was 23.33%(112/480) in patients with AKI but 3-year overall hospital mortality was 1.49%(953/64058) in all patients.4. Risk factors for mortality in patients with AKIIn-hospital mortality of middle-aged(35-59years) and elderly(60-88years) patients was significantly higher than the adolescent(0-20years) and youth(21-34years), which was 25.29%(44/174),27.68%(49/177),and 13.64%(9/66),15.87%(10/63) respectively (W=85424.50, P=0.011). Similarly, in-hospital mortality had significant differences with the increasing in the number of organ failure(from 0 to 4), which was 0.00%(0/179),6.88%(11/160),and 57.14%(44/77),86.53%(45/52),100.00%(12/12) respectively (W=70347.00,P=0.000).A multivariable logistic regression model was entered to assess for independent factors associated with death in hospital for patients with AKI. The analysis showed that the number of organ failure [OR 12.268,95%CI (7.639,19.701)] and elder[OR 1.488,95%CI(1.030,2.151)] were associated with poor prognosis. Hosmer-Lemeshow goodness-of-fit test showed that the model was statistically significant without bias (x2=6.126, df=8,P=0.633).ConclusionsCauses that prerenal and renal are main ones, elder is in the majority'. In-hospital mortality is increased significantly in patients with AKI. The adding in the number of organ failure and elder were the risk factors for death of patients with AKI. It is crucial to raise the awareness of medical staff and dynamic renal function testing for early diagnosis. In elderly patients prone to multiple organ failure, treatments would have little effect if this happens. Hence it is of benefit that timely intervention of prompt and effective complex therapy to protect important organs function for improving prognosis by multi-department.