| BackgroundSepsis is one of the most common causes of death in emergency and critically ill patients.The heart is a common affected organ.About 50%of patients with sepsis show signs of myocardial dysfunction and are associated with 70-90%of high mortality,which is defined as septic cardiomyopathy(SCM).Echocardiography is the main method for SCM evaluation,since left ventricular ejection fraction(LVEF)is greatly affected by loading conditions,strain measurement of speckle-tracking echocardiography(STE)start to rise.Compared with LVEF,the global longitudinal strain(GLS)in strain parameters is more reliable,sensitive and reproducible in detecting systolic myocardial dysfunction.In recent years,clinical researches had applied it to the evaluation of SCM and made some discoveries.ObjectiveFirstly,through subgroup analysis based on SCM consensus,this study focused on the relationship between early strain parameters and laboratory indicators,conventional ultrasound and hemodynamic parameters in patients with sepsis,expounded the supplementary effect of GLS on LVEF,and put forward the echocardiographic time window for emergency patients.Then,based on the short-term prognosis,the differences of various parameters between groups were discussed,and whether GLS is an independent predictor of mortality was analyzed.The last part combined the newly designed ultrasonic intelligent assistance and quality control system(SmartEchovue)to verify its feasibility in practical operation.The purpose of this paper is to provide clinical data basis for larger scale SCM research and ultrasound teaching in the future,in order to contribute to the final realization of early detection,early intervention and prognosis of SCM.MethodIn the first part of this study,the early vital signs,laboratory tests,hemodynamic indexes and bedside ultrasound parameters of emergency patients with sepsis/septic shock were analyzed through a cross-sectional study to explore the early characteristics and manifestations of SCM.The second part explored the differences of laboratory tests and bedside ultrasound parameters in survival and non-survival groups in patients with sepsis/septic shock in emergency department through a prospective cohort study,focusing on the relationship between strain parameter GLS and short-term/long-term mortality prognosis.as well as various related factors affecting prognosis.In the last part,a randomized controlled trial was designed to study its impact on the practical of emergency physicians by using the new bedside ultrasound intelligent assistance and quality control system(SmartEchovue).ResultThrough the first part of the study,we found that there was no significant difference in various early strain parameters between subgroups of sepsis and septic shock,but GLS and GCS were significantly less negative in subgroups with abnormal troponin(cTnI)level and LVEF(p<0.05).Also,there was a moderate correlation between GLS and the level of laboratory tests cTnI or NT proBNP(r=0.40;r=0.44).Although there was no significant difference in diastolic parameters among subgroups.The second part of the study showed that the early GLS parameters of patients in the short-term non-survival group were significantly less negative than those in the survival group.GLS with cut-off value of-15.5%had the best short-term prognostic value(AUC=0.80,p<0.001),and it was also significant in long-term prognosis(p<0.01).Through Logistic regression analysis,we found that GLS(p=0.03)rather than LVEF(p=0.61)was an independent predictor of long-term mortality in sepsis and septic shock.The third part of the study showed that after the intervention of SmartEchovue system,the cardiac standard section scanning score(p<0.05)and the degree of operation proficiency and confidence(p=0.03)of the experimental group were higher than those of the control group.It was also found that the scores of the second round of test were higher and the timing was less than that of the first round of test(p<0.05).ConclusionEarly myocardial dysfunction in patients with sepsis,such as lower LVEF or less negative GLS,is more affected by myocardial injury,and has no significant correlation with occurrences of shock.It is necessary to arrange early echocardiographic scanning for sepsis or septic shock patients with abnormal troponin level in emergency department.If possible,the strain parameter GLS can be incorporated into mainstream clinical practice as a supplement to LVEF.In addition to early diagnostic value,GLS is also associated with both short-term and long-term mortality in patients with sepsis/septic shock,and GLS rather than LVEF is an independent predictor of long-term mortality in such patients.For the short board of cardiac ultrasound in emergency physicians,short-term centralized practical operation training can significantly improve the score of cardiac standard section scanning,shorten the acquisition time,and increase the operators’ proficiency and confidence.The novel SmartEchovue system shows its advantages in simulation teaching,and also prompts us to further explore its feasibility in various clinical situations. |
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