The Etiology Analysis And Risk Factors Influencing The Prognosis Of Acute Kidney Injury

BackgroundAcute kidney injury (AKI),which refers to a short time caused by multiple factors (hours to days) in the sudden decline in renal function in clinical syndrome. In recent decades, although many researches on AKI in the etiology, pathogenesis, diagnosis and treatment have made very great progress, but they still lack effective intervention measures in clinic. The morbidity and mortality of AKI increased year by year in worldwide. Researches show that the incidence of ordinary patients with AKI is about 1.9%,in critically ill patients the incidence is as high as 30%,and the mortality is around 50%. More unfortunately, the mortality did not decline nearly 50 years.Many studies show that early diagnosis and intervention of AKI has very important significance to improve its prognosis. According to the KDIGO guidelines, serum creatinine and urine volume is still being biomarkers for the diagnostic criteria of AKI.Many researches pointed out that the application of serum creatinine and urine volume as the biomarker is difficult to reach the goal of early diagnosis of AKI, because the blood creatinine and urine volume are easy to be disturbed by many factors. In recent years, the study of early renal injury biomarkers has become a hot spot in the field of kidney disease.Over the past decade,the application of unbiased functional genomic and proteomic technologies has identified a number of novel AKI biomarkers. At present, most research of new biomarkers for early diagnosis with cystatin C, neutrophil gelatinase associated lipocalin, interleukin 18, kidney injury molecule 1, liver type fatty acid binding protein, sodium hydrogen exchange 3, retinol binding protein,etc. Although these biomarkers in numerous studies have shown a role in early diagnosis of AKI,such as what is the standard value of the biomarkers, how to use them(in contrast-induced nephropathy, operation related nephropathy or sepsis nephropathy),how to combined use of them and so on, which still need a large number of large sample and multi center randomized controlled trials to provide evidence.In early prevention of AKI, different researches provide different clinical evidence. It still failed to reach a unified in the prevention and treatment on AKI with drugs as a sodium bicarbonate, type B cysteine, statins, fenoldopam, dopamine, adenosine receptor antagonists and so on. In the treatment of AKI, including symptomatic supportive treatment and renal replacement therapy. The basic principles of the application of renal replacement therapy in AKI have not yet been established, including the optimal indications (peritoneal dialysis, intermittent hemodialysis, continuous renal replacement therapy,etc),dose and timing.AKI can appear in many clinical departments,which has badly effect on the quality of life and long-term outcomes. The occurrence and development of AKI not only occuppied more medical resources and prolong the time in hospital, but also brought heavy economic burden to the families and society. More and more researches indicate that the prognosis of patients with AKI is poor. Some important researches proved that AKI is a risk factor of chronic kidney disease.In 2012, Kidney Disease Improving Global Outcomes developed a new standard of AKI staging. It defined AKI as an increase in Scr by≥0.3mg/dL within 48 hours or an increase in Scr to≥1.5 times baseline, which is known or presumed to have occurred within the prior 7 days; or an urine volume<0.5ml/kg/h for 6 hours. In addition,KDIGO guidelines also revised the prevention and treatment of AKI.Based on the above background, this study retrospectively collected the clinical characteristics of 275 cases of AKI in Huadu District People’s Hospital from January,2010 to December,2012.By analyzing the clinical characteristics,causes and prognosis of the patients with AKI, and putting forward the risk or protective factors associated with prognosis, to provide the clinical evidence to improving the prognosis of AKI.ObjectiveTo analyze the etiology of acute kidney injury and explore the risk factors of prognosis for patients with acute kidney injury(AKI).In order to help clinicians better understand and prevent AKI.MethodsThis study retrospectively collected the clinical characteristics of patients with AKI in Huadu District People’s Hospitalfrom January,2010 to December,2012.According to the exclusion and inclusion criteria, ultimately selected 275 cases of patients with AKI. Retrospectively review the clinical data of patients with AKI, specific indicators are as follows:sex, age, clinical department, hospitalization time, medical history, the basis of disease,the basis of kidney disease, the course of original disease, the accompanying symptoms, causes, white blood cell, hemoglobin, platelet, blood potassium, sodium, serum albumin, carbon dioxide combining power, blood creatinine, urea nitrogen,24 hour urine volume, renal replacement therapy or not, mechanical ventilation or not, use or not of vasoactive drugs. According to the ages, the patients were divided into 3 groups, the youth group (<40 years old), middle aged group (40-60 years old), elderly group (≥61 years old). According to AKI diagnosis and staging criteria formulated by the KDIGO in 2012,the cases were divided into the 1stage,2 stage,3 stage. According to the etiology, the patients were divided into 3 groups of prerenal causes, intristic causes and postrenal causes.Taking the time to discharge as the observation point, the results will be divided into survival group and death group. Applicated statistical software (SPSS13.0) for statistical analysis. The main statistical methods of t test, chi square test, single factor correlation analysis and Multiunivariate analysis. P<0.05 is as a statistical significance.Results1.The clinical characteristics of AKI patientsAmong the 275 AKI patients,181 cases were male (65.8%),94 cases were female (34.2%),the average age was (56.9±19.6) years old,≤40 years old 54 cases, accounting for 19.6%, (40-60) years old group 97 cases, accounting for 35.3%,≥61 years old 124 cases, accounting for 45.1%. AKI occurred in most departments and the incidence was constituted by departments of General medicine(43.3%), Surgery(26.5%), Nephrology(20.7%), ICU(8.0%), Obstetrics(1.5%). At the end point of discharge date,the mortality was constituted by departments of General medicine(5.0%), Surgery(40.0%), Nephrology(22.8%), ICU(59.1%), Obstetrics(0.0%).275 cases of patients with AKI stagel in 88 cases, accounting for 32%, stage2 83 cases, accounting for 30.2%,104 cases in stage 3, accounted for 37.8%. Prerenal acute renal injury was the most common cause, accounted for 55.6%, of which the most common cause is infection, with pulmonary infection induced sepsis is the most common, followed is cardiovascular and cerebrovascular diseases. Drug is the most common factor of intristic causes, then infection associated diseases, tumor associated nephropathy, glomerulonephritis followed.Urinary tract stones is the most common in postrenal acute kidney injury, the tumor metastasis and invasion followed.2. Analysis of the prognosis of AKAccording to the different causes, the mortality of prerenal causes was 30.7%, intrinsic causes was 16.7%, postrenal causes was 1.8%. The mortality of prerenal causes is the highest, the difference was statistically significant between the 3 groups (x2=21.546, P<0.01). According to the different mode of renal replacement therapy, the mortality of intermittent hemodialysis was 5.6%, continuous renal replacement therapy was 44.7%, the difference was statistically significant prognostic treatment between the two groups (x2=8.597,P<0.01).Taking the time to discharge as the observation point, the results will be divided into survival group and death group. By compairing the clinical characteristics of the two groups. Univariate analysis showed that hospital onset, hypertension, sepsis or septic shock, multiple organ dysfunction syndrome, hypoproteinemia, acidosis, history of diabetes, renal replacement therapy, the use of vasoactive drugs, mechanical ventilation is the risk factors to increase the hospital mortality rate of AKI patients. Multiunivariate analysis showed that mechanical ventilation of multi factors (OR=2.445,95%CI: 1.018～5.871), vasoactive drugs (OR=43.530,95% CI:9.204～205.884) MODS (OR=2.801,95%CI:1.091～7.194)、hypoproteinemia (OR=3.118,95%CI:1.212～ 8.022) are independent risk factors for death in patients with AKI.ConclusionAKI is a common and serious complication in critically ill patients which have high occurrence rate and mortality. The prerenal causes of infection, cardiovascular and cerebrovascular diseases are relatively common,which should be early diagnosis and intervention. Mechanical ventilation, vasoactive drugs, MODS, hypoproteinemia were the independent risk factors of death of the patients with AKI. Only independent AKI stage which published by KDIGO is not a good predictor of the prognosis of AKI, the related factors such as the severity of disease, clinical status, medical level and economic level and so on should be concerned.