To explore the sedative effect of Remimazolam on patients with mechanical ventilation in intensive care unit (ICU) and its influence on respiratory and circulatory system.

In a prospective randomized controlled study, ninety-two mechanical ventilated patients who needed sedation were enrolled in ICU of Xinyang Central Hospital from January 2021 to September 2021. The patients in two groups were given Sufentanil for analgesia, with critically-ill pain observation tool (CPOT) score less than 2 points, and were randomly divided into two groups, including 45 cases in Remimazolam group (group R) and 47 cases in Propofol group (group P). In group R, patients were received Remimazolam at a loading dose of 7 mg and an additional dose of 2.5 mg (when sedation target of RASS was not reached) by intravenous injection, and then a maintenance dose of 0.1-0.5 mg/(kg·h) by intravenous pump. In group P, patients younger than 55 years old were received Propofol at 0.5-1.5 mg/kg by intravenous injection (patients older than 55 years old were received at a reduced dose as appropriate) followed by a 0.1-1 mg/(kg·h) maintenance dose by intravenous pump. According to RASS sedation score, the target sedation depth of the two groups was maintained at -2- -3 points. The time to onset of effect of drugs and the wake-up time of the patients (after the withdrawal of the drug) were recorded and compared between the two groups. The changes of heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), left ventricular ejection fractions (LVEF), left ventricular outflow tract velocity time integral (VTI), respiratory rate (RR) and saturation of pulse oxygen (SpO₂) were recorded and compared between the two groups before (T0) and at 1 h (T1), 6 h (T6), 12 h (T12) and 24 h (T24) after medication.

We found no difference between baseline clinical data such as gender, age, height, weight, APACHE Ⅱ score and hemodynamic or respiratory parameters before treatment between the two groups. There was no significant difference of the time to onset of effect of drugs between group R and group P after treatment [(85.7±18.6) s vs (94.7±32.6) s, P=0.108]. After administration stopped, wake-up time of group R was shorter than that of group P [(22.6±6.25) s vs (25.9±7.9) s, P=0.028]. Compared with T0 time point, the mean values of HR, SBP, DBP, RR, LVEF and VTI recorded at T1, T6, T12 and T24 time points in the two groups all decreased, while the mean values of SpO₂ increased. Intra-group analysis showed that there were statistically significant differences between the above parameters at each time point after administration and before administration (P＜0.01). Inter-group analysis showed that there were statistically significant differences in mean values of HR_{(T1, T6, T24)}, SBP_{(T1, T6, T12, T24)}, DBP_{(T1, T6, T12)}, LVEF_{(T1, T6, T24)} and VTI_{(T1, T6, T24)} between the two groups (P＜0.05),However, there was no significant difference in RR and SpO₂ between two groups at T1-T24 time points (P＞0.05).

Either Remimazolam or Propofol have the advantage of rapid onset. When compared with Propofol, patients who received Remimazolam are more easier to wake-up (after administration stopped) and has less influence on heart rate, blood pressure and cardiac systolic function, which is more suitable for sedation treatment of ICU patients.