Effect Of 6%Hydroxyethyl Starch 130/0.4 Versus 4%Gelatin In Major Surgery On Postoperative Acute Kidney Injury

Background and ObjectivesAcute kidney injury(AKI)is one of the most frequent complications after major surgery,with unclear mechanism of its development,which is influenced by various factors.AKI prolongs the length of hospital stay,and results in increased cost and poor prognosis.The incidence of AKI varies greatly since different type of surgery and diagnostic criteria.It was reported that the incidence of AKI after major surgery varies from 3%～35%.Perioperative fluid therapy is essential to maintain stable hemodynamic in elective major surgery.As plasma substitutes,colloids are widely used during major surgery.They usually produce intravascular volume expansion more quickly and receive lower cumulative volumes than crystalloid in patients.6%Hydroxyethyl starch 130/0.4(HES)and 4%gelatin(GEL)are widely used in clinic.However,the effects of HES and GEL on postoperative renal function are still controversial.In present study,we retrospectively analyzed all major surgery cases between May 2019 and September 2021,and compared the effects of 6%HES 130/0.4 and 4%GEL on AKI after major surgery,so as to provide reference for clinical application.MethodsA total of 15138 patients who underwent major surgery were included.Exclusion criteria were:(1)<18 years of age;(2)underwent emergency surgery;(3)both GEL and HES were used intraoperatively or neither of them;(4)incomplete serum creatinine measurement before and after surgery;(5)had end-stage renal disease(defined as receiving preoperative renal replacement therapy or estimated glomerular filtration rate less than 15 ml min-1[1.73 m]-2).1)Propensity score(PS)matching was used to minimize the impacts of potential confounding factors.A propensity score was calculated using logistic regression.Patients in the HES group was matched with those in GEL group for a 1:1 ratio with the nearest-neighbor matching method,a caliper value of 0.02.2)Continuous data was undergone the test of normality(Kolmogorov-Smimov method).For those meeting non-normal distribution were presented as median(interquartile range).Inter-group differences were compared using Mann-Whitney U test.Categorical outcomes were presented as frequency and percentage,and were compared using Chi-square or Fisher’s exact test,as appropriate.3)The risk of postoperative AKI was estimated by binary logistic regression models with adjustment for confounders.For the stage of AKI,ordered logistic regression models were used.4)The association between colloid administration and postoperative AKI were analyzed in following predefined subgroups of overall patients:preoperative hypoalbuminemia or not,decreased or normal preoperative renal function,with or without IOH,and the use of vasoactive drug intraoperatively.All statistical analyses were performed with R software,version 4.2.0(R Foundation for Statistical Computing Vienna,Austria).A P value of less than 0.05 was accepted as being statistically significant.Results1)A total of 7297 patients who underwent major surgery were included(HES group=1435,GEL group=5862).AKI occurred in 62 cases(4.3%)in the HES group and 235 cases(4.0%)in the GEL group.There was not statistically significant difference towards the incidence(P=0.592)and stage(P=0.876)of AKI.2)Propensity score matching produced 1433 matched pairs.AKI occurred in 62 cases(4.3%)in the HES group and 59 cases(4.1%)in the GEL group.There was not statistically significant difference towards the incidence(P=0.780)and stage(P=0.522)of AKI.3)The results of multivariate analysis showed that age,hypertension,chronic heart failure,preoperative serum creatinine,vascular surgery,blood loss,and duration of surgery were independent risk factors associated with postoperative AKI.Multivariable analysis after adjusting for confounding factors revealed that HES was not correlated with the incidence of postoperative AKI(odds ratio 1.14,95%confidence interval:0.77-1.69)and the severity of AKI(OR 1.17,95%CI:0.79-1.73)compared with GEL.4)Subgroup analyses showed that there was no interaction between colloid type and any stratification on the incident postoperative AKI(all P>0.05).ConclusionsIn this propensity score-matched cohort study,we found that the use of 6%hydroxy ethyl starch 130/0.4 during surgery did not increase the incidence or severity of postoperative AKI compared to the use of 4%GEL.These results indicate that it may not be necessary to be concerned about 6%HES 130/0.4 associated with higher renal damage during the elective surgery.