Application effects of remimazolam and propofol on elderly patients undergoing hip replacement
Authors: Zhang Junbao , Wang Xin , Zhang Qing , Wang Zicheng , Zhu Shoufeng 
Published: April 2022

Abstract
Objective
To explore the anesthetic and analgesic effects of remimazolam and propofol in elderly patients undergoing hip replacement and their effects on respiratory and circulatory systems, stress and cognitive function.

Methods
Sixty elderly patients undergoing elective hip replacement in the hospital were selected as the research subjects, and they were divided into the remimazolam group and the propofol group according to the admission sequence of patients. The remimazolam group was anesthetized with remimazolam, and the propofol group was anesthetized with propofol. The anesthesia-related indicators, perioperative pain degree [Visual Analogue Scale (VAS)], circulatory indicators [heart rate, mean arterial pressure (MAP)] before anesthesia (T0), immediately before laryngeal mask insertion (T1), at 5 min after laryngeal mask insertion (T2), at 30 min after laryngeal mask insertion (T3) and at 5 min after laryngeal mask removal (T4), stress response indicators (plasma epinephrine, norepinephrine, cortisol) before anesthesia induction and at 24 h and 72 h after surgery, cognitive function [Mini-Mental State Examination (MMSE)] and adverse reactions were compared between the two groups.

Results
Among the 60 enrolled patients, only 1 case was excluded due to withdrawal, thus 30 cases in the remimazolam group and 29 cases in the propofol group were included. There were statistically significant differences in the heart rate, MAP, plasma epinephrine, norepinephrine, cortisol and VAS score in the two groups from the aspects of interaction effect and time-point effect (P < 0.05). The heart rate and MAP at T1, T2 and T3 in the two groups were significantly decreased compared with those at T0, but the heart rate and MAP in the remimazolam group at T1, T2 and T3 were significantly higher than those in the propofol group (P < 0.05). There were no statistical differences in the anesthesia time, awakening time and extubation time between the remimazolam group and the propofol group (P > 0.05). The levels of plasma epinephrine, norepinephrine and cortisol in the two groups were significantly higher at 24 h and 72 h after surgery than those before anesthesia induction, and the above levels were significantly lower in the remimazolam group than those in the propofol group (P < 0.05). The VAS scores at each time point in the two groups were significantly reduced compared to before surgery, but there was no statistically significant difference between the two groups after surgery (P > 0.05). The MMSE scores of the two groups were significantly lower at 1 d and 3 d after surgery compared with those before anesthesia induction, but the score in the remimazolam group was significantly higher than that in the propofol group (P < 0.05). In addition, the incidence rates of adverse reactions were significantly lower in the remimazolam group compared to the propofol group (P < 0.05).

Conclusion
Compared with propofol, remimazolam can achieve equivalent anesthetic and analgesic effects in elderly patients undergoing hip replacement. However, the latter one can significantly relieve respiratory and circulatory suppression, stress response and cognitive dysfunction, with good safety.

Trial registration
This single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 31/12/2021 with the registration number ChiCTR2100055039.