The Effect Of Initiation Times Of Renal Replacement Therapy On Mortality In Critically Illpatient With Acute Kidney Injury

Purpose : Acute kidney injury(AKI)is one of the most common complications for critically ill patients,and renal replacement therapy(RRT)is one of the key supportive therapies for these patients.The timing of RRT initiation in critically ill patients is controversial.The purpose of this study was to investigate the effect of initiation times of RRT for critically ill patient with AKI.Methods: There were 170 patients who were admitted to the intensive care unit(ICU)of Sichuan Provincial People's Hospital from June 2017 to June 2019.We only included patients who were diagnosed with AKI stage 2 or above(according to the KDIGO guideline).The exclusion criteria included patients younger than 18 years old,patients with chronic kidney disease,kidney transplantation,or received regular RRT before admission to ICU,as well as patients' death occurring within 24 hours,and finally total 114 patients were enrolled in this study.According to the timing of dialysis,the patients were divided into early group,late group and non-dialysis group.The early group was defined as RRT started within 12 hours after the diagnosis of AKI stage 2,and the late group was defined as RRT begins at diagnosis of AKI-2 or above with at least one ofthe following conditions(severe hyperkalemia,metabolic acidosis,acute heart failure,blood urea nitrogen(BUN)>100mg/dl [35.7mmol/L]).28-day mortality was recorded for all patients after admission to ICU.Collect baseline characteristics before RRT,including age,gender,primary diagnosis,laboratory parameters(including creatinine,BUN,arterial blood gas,arterial lactic acid,arterial bicarbonate,electrolyte,serum albumin,brain natriuretic peptide,white blood cells,platelets and erythrocyte sedimentation rate),APACHE II score,SOFA score,mean arterial pressure and vasopressors,urine output 24 h before RRT,liquid equilibrium accumulates over 24-hours,as well as the time and mode of RRT.Parameters for outcomes,including ICU length of stay,mechanical ventilation time,RRT complications,total RRT time,28-day death,were collected.Comparison of the effects of different timing of dialysis on the outcomes of the patients.Results: For all the 114 patients,55 patients had stage 2 of AKI,of which 37 were treated with RRT and 18 without RRT,and 59 patients had stage 3,of which 49 were treated with RRT and 10 without RRT.There were 43 patients(37.7 %)with sepsis or septic shock,31 patients(27.2 %)with cardiac surgery,15 patients(13.2 %)with severe pancreatitis,and 11 patients(9.6 %)with liver failure.There were 46cases(40.4%)in the early dialysis group,40 cases(35.1%)in the late dialysis group,and 28 cases(24.6%)in the non-dialysis group.There was no significant difference in SOFA score(11.04 ± 3.18,10.80 ± 3.20,10.11 ± 3.02,P = 0.458)among the three groups.The APACHE ?score was the highest in the late dialysis group(18.00 ± 7.42,18.55 ±6.21,14.68 ± 2.86,P = 0.704),and The time of mechanical ventilation was significantly longer in the dialysis group,the longest in the late group(5.93 ± 3.91,8.80 ± 14.19,2.54 ± 2.08 days,P = 0.017).the mean arterial pressure was higher in the dialysis groups(81.32 ± 16.23,77.60 ± 17.92,68.11 ± 6.03 mmHg,P = 0.002),the BUN(16.16 ± 11.06,27.56 ± 22.55,8.67 ± 2.82 mmol / L,P < 0.001)and serum creatinine level before dialysis(235.5 ± 191.3,327.8 ± 217.5,181.5 ± 72.4 ?mol/L,P = 0.004)were significantly higher in the dialysis group,and highest in the late dialysis group.There was no significant difference in 28-day mortality among the three groups(P = 0.149).While mean arterial pressure(OR1.045,95% CI: 1.011 to 1.080,P = 0.01)and 24-hour urine volume before RRT(OR 17.631,95% CI: 6.332 to 49.171,P = 0.000)might be the risk factors for 28-day mortality.Further stratified analysis showed that age,lactate level,and SOFA score was a risk factor affecting the prognosis of patients in the early dialysis group.the mean arterial pressure was a risk factor affecting the prognosis of patients in the late dialysis group.Age and mechanical ventilation time were a risk factor affecting the prognosis of patients without dialysis.There was no significant difference in 28-day mortality among the three groups after stratified analysis.Patients with sepsis had the longest ICU stay in the late dialysis group and the shortest ICU stay in the non-dialysis group(18±17.4,23.2±13.7,17.2±14.7 days,P=0.025).Survival analysis showed that there was no difference in 28-day survival rate among the three groups(P = 0.559).24 hours urine volume and SOFA score before RRT affected 28-day survival time(P = 0.0001)Conclusion: Sepsis was still the primary cause of AKI in critically ill patients,followed by cardiac surgery.There was no significant effect of early or late initiation of RRT on 28-day mortality in critically ill patients with AKI.Mean arterial pressure and urine output 24 h before RRT may be associated with 28-day mortality.Age,lactic acid level and SOFA score was a prognostic factor for 28-day mortality at the early dialysis group.Mean arterial pressure is a prognostic factor for 28-day mortality in patients with late dialysis.