Effect Of Mean Arterial Pressure On Prognosis Of Patients With Septic Shock With Different Lactate Clearance Rates

Objective: After comparing the patients with different postoperative LCR maintained under high or low MAP for 3d,Differences in 3d all-cause mortality,30 d all-cause mortality,duration of mechanical ventilation,percentage of RRT,and length of stay in ICU.To investigate whether short-term maintenance of high MAP improves outcomes in patients with low LCR septic shock after resuscitation.Method: Based on a retrospective cohort study,from the MIMIC-Ⅳ database of intensive care patients from US medical centers from January 2008 to December2019,Patients meeting the diagnostic criteria for septic shock and related information were extracted and divided into high LCR group and low LCR group according to whether the LCR was greater than 20% after 6h of resuscitation.Furthermore,patients were divided into high MAP group and low MAP group according to whether the mean value of 3d MAP was greater than 75 mm Hg(1mm Hg=0.133KPa).Intergroup baseline data were balanced by a propensity score matching.After resuscitation,3d all-cause mortality,30 d all-cause mortality,mechanical ventilation duration,RRT ratio and length of ICU stay were compared between the high and low MAP groups,respectively.Multivariate logistic regression model was established to further explore the effect of MAP and other variables on 3d and 30 d mortality.A 30 d Kaplan-Meier survival curve was drawn to observe the effect of MAP on mortality over time,and the log-rank test was conducted.Result: Finally,941 patients with low LCR and 542 patients with high LCR were extracted from the database.After 1:1 propensity score matching,768 patients with low LCR and 420 patients with high LCR were included in the analysis.In the low LCR population,the high MAP group had lower 3d and 30 d mortality than the low MAP group,and the difference was statistically significant(13.28% vs.19.01%,P=0.031)and(41.93% vs.49.22%,P=0.042).There were no significant differences in mechanical ventilation duration(81h vs.88 h,P=0.653),RRT ratio(28.65% vs.26.69%,P=0.751)and ICU stay(18.5d vs.19.8d,P=0.259).In the high LCR population,there was no significant difference in 3d and 30 d mortality between the high MAP group and the low MAP group(9.05% vs.8.10%,P=0.727)and(30.00%vs.37.14%,P=0.121).There were no significant differences in mechanical ventilation duration(47h vs.71 h,P=0.330),RRT ratio(16.67% vs.23.81%,P=0.069),length of ICU stay(14.3d vs.19.8d,P= 0.101).Multivariate Logistic regression analysis suggested that maintaining high MAP within 3d could significantly reduce 3d mortality(OR=0.620,95%CI: 0.410-0.938,P=0.023)and 30 d mortality(OR=0.732,95%CI: 0.540-0.991,P=0.043),maintaining high MAP within 3d did not significantly reduce 3d mortality(OR=1.153,95%CI: 0.570-2.330,P=0.692)OR 30 d mortality(OR=0.731,95%CI: 0.480-1.114,P=0.145);Survival curves showed that maintaining a high MAP within 3 days after resuscitation improved mortality in people with low LCR,but the effect decreased with the extension of survival time.Conclusion: For septic shock patients with different LCR after resuscitation,short-term maintenance of high or low MAP had no significant effect on mechanical ventilation time,RRT ratio,ICU stay.In people with low LCR after resuscitation from septic shock,short-term maintenance of high MAP significantly reduces mortality.