Evaluation Of Death Risk And Research Of Renal Replacement Therapy In Patients With Septic Shock

Part 1 Evaluating the risk of death of the patients with septic shock by the clinical analysisObjective Multiple organ dysfunction syndrome(MODS)caused by septic shock is a major cause of death in critically ill patients.Many of the patients died at the early stage because of the lack of timely treatment.In this part,we hope to assess the risk of death in patients with septic shock through the effective analysis and integration of the clinical parameters.Method 198 septic shock patients were selected randomly from the database between January 2009 and December 2014.The patients with septic shock were divided into early death group(5 days),the late death group(6-28 days)and survival group(>28 days)according to the regularity of time distribution of death.The general characteristics,clinical and laboratory parameters of the three groups were compared.The influence of the parameters on the mortality and the time of death were analyzed.The risk model for death was constructed based upon the parameters and verified by ROC curve.Results:When compared to the patients with later death and surviors,the patients of early death had lower systolic blood pressure(P<0.001)and diastolic blood pressure(P<0.001),lower white blood cell(P=0.011),lower albumin(P=0.009)level and significantly decreased pH value(P<0.001).When comparing with survivors,more died patients had acute kidney injury(AKI)(P<0.001),diabetes mellitus(P=0.042)and coronary heart disease(P=0.049)and the need for mechanical ventilation(P<0.001),and the death patients had lower body temperature(P=0.016),higher respiratory rate(P=0.010),higher uric acid(P=0.002)prolonged APTT(P=0.001),higher lactic acid level(P<0.001)and significantly higher acute physiology and chronic health evaluation(APACHE Ⅱ)(P<0.001)and sequential organization failure assessment(SOFA)score(P<0.001).The serum uric acid(HR=1.001,P=0.037),PH value(HR=0.089,P<0.001),APTT(HR=1.012,P=0.001)and blood lactate levels(HR=1.088,P=0.016)were independent risk factors for death according to Cox proportional hazards model multi factor analysis.Combined with the above 4 parameters to establish a risk model of death,ROC curves suggested that the area under the curve(AUC)of mortality risk model was of 0.726,sensitivity of 76.5%,specificity of 59.2%,which superior to SOFA score(AUC of 0.671,sensitivity of 68.6%,specificity of 54.1%)and APACHE Ⅱ score(AUC of 0.630,sensitivity of 68.6%,specificity of 54.1%).Conclusion:When septic shock occurs,the patients with significantly lower blood pressure,lower white blood cell,hypoalbuminemia and severe decompensated acidosis may be at risk of early death,and the patients with lower body temperature,higher respiratory rate,higher uric acid,prolonged APTT,higher lactic acid and significantly increased APACHE Ⅱand SOFA score suggested the severity of the disease.The patients combined AKI,diabetes,coronary heart disease and the need for mechanical ventilation showed a greater risk of death.Combining detection of blood uric acid,pH value,APTT and blood lactic acid to establish the risk model is helpful to predict death risk in patients with septic shock.Part 2 The effect and timing of initiation of renal replacement treatment in patients with septic shockObjective To investigate clinical value of RRT in the treatment of septic shock,we compared to clinical characteristics and laboratory parameters in the accepting RRT and non RRT patients,and the effect of RRT on prognosis was evaluated.To explore appropriate RRT start time,the relationship between the biochemical parameters of starting RRT and the prognosis were analyzed in the patients with septic shock.Methods 87 patients with RRT and 111 patients without RRT of 198 patients with septic shock were included in this part of the study.The differences of clinical and laboratory parameters were compared.The effect of RRT on prognosis was analyzed by multivariate Cox proportional hazard model.In addition,the patients with RRT were divided into different levels based on the pH value,APACHE Ⅱ and SOFA score,AKIN grading and from occurring shock to the starting time of RRT.The mortality and the survival rate were compared in different lays.Results The early mortality of the patients with RRT was lower than the patients without RRT(P<0.001),but 28 days mortality was similar in the two groups(P=0.738).When compared to the patients without RRT,the patients with RRT had more complication including AKI(P<0.0001),tumor(P=0.038),coronary heart disease(P=0.021),congestive heart failure(P=0.049)and higher APACHE Ⅱ(P<0.001).RRT was a beneficial factor of patients recovery(β=-1.125,HR=0.325,95%confidence interval 0.182-0.580,P<0.001)according to Cox proportional hazard model multivariate analysis.Stratified analysis found that the mortality rate had an increasing trend when the pH value gradually decreased(r=-3.840,P<0.001),and APACHE Ⅱ(r=3.793,P<0.001)and SOFA score(r=7.143,P<0.001)gradually advance.RRT start time after the occurrence of septic shock was positively correlated with 28 day mortality(r=3.369,P=0.001),and the time from occurring shock to start RRT was independent effect factors of death in patients with RRT(β=0.540,HR= 1.175,P=0.031)).Conclusion The patients with septic shock accepting RRT is more critical than without RRT.RRT is beneficial therapeutic method in patients with septic shock.The lower pH level and the higher APACHE Ⅱ and SOFA score in initiation of RRT indicate poor prognosis.Starting timely RRT after septic shock may improve the prognosis of the patients.Part 3 The effects of renal replacement treatment model on prognosis in patients with septic acute kidney injuryObjective Whether continuous renal replacement treatment(CRRT)or intermittent renal replacement treatment(IRRT)superior to for the treatment of septic AKI is unknown.We compared the effect of continuous venovenous hemofiltration(CVVHF)(greater than 72 hours)with extended daily hemofiltration(EDHF)(8 to 12 hours daily)on renal recovery and mortality in patients with severe sepsis or septic shock andconcurrent acute kidney injury(AKI).Methods A retrospective analysis of 145 septic AKI patients who underwent renal replacement therapy(RRT)between July 2009 and May 2013 was performed.These patients were treated by CVVHF or EDHF with the same polyacrylonitrile membrane and bicarbonate-based buffer.The primary outcomes measured were occurrence of renal recovery and all-cause mortality by 28 days.Results:Sixty-five and eighty patients were treated with CVVHF and EDHF,respectively.Patients in the CVVHF group had significantly higher recovery of renal function(50.77%of CVVHF group versus 32.50%in the EDHF group,P= 0.026).Median time to renal recovery was 17.26 days for CVVHF patients and 25.46 days for EDHF patients(P= 0.039).28 days all-cause mortality was similar between CVVHF and EDHF groups(44.62%,and 46.25%,respectively;P=0.844).55.38%of patients on CVVHF and 28.75%on EDHF developed hypophosphatemia(P=0.001).The other adverse events related to RRT did not differ between groups.On multivariate analysis,including physiologically clinical relevant variables,CVVHF therapy was significantly associated with recovery of renal function(HR 3.81;95%CI 1.90 to 7.62;P<0.001),but not with mortality(HR 0.81;95%CI 0.30 to 1.81;P=0.580).Conclusions Patients undergoing CVVHF therapy had significantlyimproved renal recovery independent of clinically relevant variables.The patients with septic AKI had similar 28-day all-cause mortality rates,regardless of type of RRT.