Effect Of Intraoperative Low Vs.conventional Tidal Volume On The Incidence Of Postoperative Acute Kidney Injury After Noncardiac Surgery

Background:In adults undergoing noncardiac surgery,the correlation between intraoperative tidal volume and postoperative acute kidney injury(AKI)is unclear.This study aimed to investigate the effects of low tidal volume ventilation on the incidence of postoperative AKI compared with conventional tidal volume in adults undergoing noncardiac surgery.Methods:This was a two-center prospective randomized controlled trial on adult patients who underwent noncardiac surgery and had a mechanical ventilation of>60 min.Patients were randomized to receive either a tidal volume of 6 mL/kg pre-predicted body weight(low tidal volume)or a tidal volume of 10 mL/kg pre-predicted body weight(conventional tidal volume).The primary outcome was the incidence of AKI after non-cardiac surgery.All statistics were analyzed using SPSS 25.0 and Jamovi 2.3.Results:Among the 1982 randomized patients,943 with low tidal volume and 958 with conventional tidal volume were evaluable for the primary outcome.Postoperative AKI occurred in 12 patients(1.3%)in the low tidal volume group and 11 patients(1.1%)in the conventional tidal volume group,with an odds ratio of 0.889[95%CI,0.391-2.03]and a relative risk of 0.999[95%CI,0.989-1.01];P=0.804).Elevated postoperative serum creatinine levels were observed in 284(30.0%)and 316(32.0%)patients in the low and regular tidal volume groups,respectively,with no statistically significant difference(P=0.251),No difference in postoperative serum creatinine levels was found between the two groups(57.5[49.0-68.2]μmol/L vs.58.8[50.4-69.5]μmol/L,P=0.056).Conclusion:Among adults undergoing noncardiac surgery,low tidal volume mechanical ventilation did not significantly reduce the incidence of postoperative AKI compared with conventional tidal volume.