Propofol reduced myocardial contraction of vertebrates partly by mediating the cyclic AMP-dependent protein kinase phosphorylation pathway

Comparison of the safety of remimazolam and propofol during general anesthesia in elderly patients: systematic review and meta-analysis

Background

Remimazolam is a novel sedative drug approved for procedural sedation and general anesthesia. Clinical trials have already explored its use in elderly patients for general anesthesia. For elderly patients with declining physical and physiological function, anesthesia safety is crucial. Most current clinical studies compare the safety of remimazolam and propofol, though the results are inconsistent. Therefore, we conducted a meta-analysis to compare the safety of remimazolam and propofol in general anesthesia for elderly patients.

Methods

We systematically searched the PubMed, Cochrane Library, Embase, and Web of Science databases for all published randomized controlled trials comparing remimazolam and propofol for general anesthesia in elderly patients. We synthesized data from eligible studies using relative risk or mean difference, and analyzed differences in hemodynamic stability and adverse effects between the two drugs. Data extraction and quality assessment were performed independently by two researchers.

Results

Eight randomized controlled trials involving 571 participants were included. Compared to propofol, remimazolam was associated with a lower incidence of hypotension (RR = 0.51, 95% CI: [0.33, 0.81], I 2 = 18%, p = 0.3 > 0.1) and bradycardia (RR = 0.56, 95% CI: [0.31, 1.02], Z = 1.88, p = 0.06 < 0.05). The mean arterial pressure after induction was higher in the remimazolam group (WMD = 3.95, 95% CI: [3.197, 9.498], Z = 3.95, p < 0.00001). The remimazolam group had a higher heart rate (HR) after induction compared to the propofol group (WMD = 7.89, 95% CI: [-2.39, 18.17], Z = 1.5, p = 0.13 > 0.05), but this result was not statistically significant. Among other secondary outcomes, the remimazolam group had lower incidences of injection site pain, nausea and vomiting, and hypoxemia compared to the propofol group, and also had a shorter extubation time.

Conclusion

In this meta-analysis, compared to propofol, remimazolam reduced the incidence of hypotension, bradycardia, and injection site pain during general anesthesia in elderly patients. The mean arterial pressure (MAP) and heart rate (HR) were more stable after induction. Remimazolam may be a safer sedative for elderly patients.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024516950, CRD42024516950.

Effects of Remimazolam Anesthesia with Two Induction Doses on Hemodynamics and Recovery Profile in Older Patients: Comparison with Propofol Anesthesia

Remimazolam has advantages such as hemodynamic stability and rapid onset. We investigated the effects of induction doses on hemodynamics and recovery profiles for remimazolam compared to propofol in older patients. Sixty-nine patients aged >65 years were randomly assigned to either the propofol anesthesia group (P group) or the remimazolam anesthesia group with an induction dose of 6 mg/kg/h (R6 group) or 12 mg/kg/h (R12 group), followed by 1 mg/kg/h. P group was anesthetized with 4 µg/mL of propofol effect-site concentration (Ce) with target-control infusion, followed by 2.5-3 µg/mL of Ce. The primary outcome was the difference between the baseline mean arterial pressure (MAP) and the lowest MAP during anesthesia (ΔMAP). ΔMAP was comparable between the P, R6, and R12 groups (43.8 ± 13.8 mmHg, 39.2 ± 14.3 mmHg, and 39.2 ± 13.5 mmHg, p = 0.443). However, the frequencies of vasoactive drug use were 54.5%, 17.4%, and 30.4% (p = 0.029), and the median doses of ephedrine 3 (0-6) mg, 0 (0-0) mg, and 0 (0-0) mg (p = 0.034), which were significantly different. This study showed remimazolam anesthesia with an induction dose of 6 mg/kg/h, rather than 12 mg/kg/h, could reduce the requirement for vasoactive drugs compared to propofol anesthesia.

Propofol attenuates myocardial ischemia reperfusion injury partly through inhibition of resident cardiac mast cell activation

Cardiac mast cell activation is involved in the process of myocardial ischemia reperfusion (I/R) injury and exacerbates myocardial infarction. Propofol, an anesthetic with antioxidant property, can reduce myocardial infarct size in I/R injury. The present study was designed to investigate whether propofol can attenuate myocardial I/R injury by inhibiting resident cardiac mast cell activation by a Langendorff model. Thirty rats were randomly assigned to 5 groups (n=6 per group): control group and four test groups (I/R, I/R+compound 48/80, I/R+propofol, I/R+compound 48/80+propofol). Cultured RBL-2H3 cells were pretreated with propofol and subjected to mast cell degranulator compound48/80 (C48/80).Microscopically, degradation of myofibrillar and degranulation of mast cells were studied using hematoxylin-eosin toluidine blue staining techniques. After the effluent was assayed for tryptase, LDH, CK-MB and cTnI, myocardial tissue was evaluated for cytokine levels and infarct area. Heart subjected to I/R showed significantly increased expression of cytokines (TNF-α and IL-6), LDH, CK-MB and cTnI. In addition, the I/R-induced heart also showed greater histopathological injury and a larger infarction zone, following increased mast cell degranulation with concomitant rise in tryptase. Mast cell degranulation by C48/80 further aggravated I/R injury. However, all of these effects were suppressed by propofol pretreatment, which also abrogated C48/80-mediated exacerbation of I/R injury. Also, propofol attenuated the C48/80-evoked tryptase and histamine release in RBL-2H3 cells. It is concluded that pretreatment of propofol confers protection against I/R injury partly by inhibiting resident cardiac mast cell activation.