Strengths and limitations
left ventricular dysfunction
LEFT VENTRICULAR DYSFUNCTION, HEMODYNAMIC INSTABILITY
This study has the following strengths: First of all, STE, which is less affected by cardiac preload and afterload and can be used to assess myocardial contractility more accurately, was used to assess myocardial contractility before and after Esmolol treatment in SIC patients for the first time; Secondly, a prospective randomized study design was adopted, which can well prevent selectivity bias and more accurately evaluate the effect of Esmolol; Thirdly, hemodynamic changes during medication were monitored in real time to ensure patient safety; Finally, PICCO parameters were firstly used to evaluate the effects of Esmolol on cardiac function. However, this study is still subject to the following limitations: Firstly, there is no definite threshold of STE for the evaluation of left ventricular dysfunction. However, the threshold value of left ventricular dysfunction in this study was obtained from previous large-scale studies, which reduced the possibility of exaggerating or covering up the fact of cardiac function; Secondly, STE was only used in this study for the continuous evaluation of changes in cardiac function of the enrolled patients for 7 days, failing to evaluate the influence of Esmolol on long-term cardiac function and hemodynamics. However, based on the use of vasoactive drugs and changes in hemodynamic parameters for 7 consecutive days, it can be reasonably proposed that long-term application of Esmolol will not cause hemodynamic instability; Finally, considering the effect of Esmolol on HR, the researchers could not be blinded in this study, but the selected parameters were all objective parameters less affected by subjective factors, and could affectively prevent information bias.