Propofol differentially induces unconsciousness and respiratory depression through distinct interactions between GABAA receptor and GABAergic neuron in corresponding nuclei

The safety of remimazolam versus propofol in gastroscopic sedation: a meta-analysis

BACKGROUND

This meta-analysis was designed to compare the safety and efficiency of remimazolam with those of propofol in patients undergoing gastroscope sedation.

METHODS

We searched PubMed, Cochrane Library, Embase, Ovid, Wanfang Database, China National Knowledge Infrastructure, SINOMED, and ClinicalTrials.gov for studies that reported on remimazolam versus propofol for gastroscope sedation from establishment to February 25, 2023. The sedative efficiency and the incidence of adverse events were assessed as outcomes. Version 2 of the Cochrane risk-of-bias assessment tool was used to assess the risk of bias. Review Manager 5.4 and STATA 17 were used to perform all statistical analyses.

RESULTS

A total of 26 randomized controlled trials involving 3,641 patients were included in this meta-analysis. The results showed that remimazolam had a significantly lower incidence of respiratory depression (risk ratio [RR] = 0.40, 95% confidence interval [CI]: 0.28-0.57; p < 0.01, GRADE high), hypoxemia (RR = 0.34, 95% CI: 0.23-0.49; p < 0.01, GRADE high), bradycardia (RR = 0.34, 95% CI: 0.23-0.51; p < 0.01, GRADE high), dizziness (RR = 0.45, 95% CI: 0.31-0.65; p < 0.01, GRADE high), injection site pain (RR = 0.06, 95% CI: 0.03-0.13; p < 0.01, GRADE high), nausea or vomiting (RR = 0.79, 95% CI: 0.62-1.00; p = 0.05, GRADE moderate), and hypotension (RR = 0.36, 95% CI: 0.26-0.48; p < 0.01, GRADE low).

CONCLUSIONS

Remimazolam can be used safely in gastroscopic sedation and reduces the incidence of respiratory depression, hypoxemia, bradycardia, injection site pain, and dizziness compared with propofol, and doesn't increase the incidence of nausea and vomiting.

Comparison of the respiratory effects of commonly utilized general anaesthesia regimes in male Sprague-Dawley rats

Background: Respiratory parameters in experimental animals are often characterised under general anaesthesia. However, anaesthesia regimes may alter the functional and mechanical properties of the respiratory system. While most anaesthesia regimes have been shown to affect the respiratory system, the effects of general anaesthesia protocols commonly used in animal models on lung function have not been systematically compared. Methods: The present study comprised 40 male Sprague-Dawley rats divided into five groups (N = 8 in each) according to anaesthesia regime applied: intravenous (iv) Na-pentobarbital, intraperitoneal (ip) ketamine-xylazine, iv propofol-fentanyl, inhaled sevoflurane, and ip urethane. All drugs were administered at commonly used doses. End-expiratory lung volume (EELV), airway resistance (Raw) and tissue mechanics were measured in addition to arterial blood gas parameters during mechanical ventilation while maintaining positive end-expiratory pressure (PEEP) values of 0, 3, and 6 cm H2O. Respiratory mechanics were also measured during iv methacholine (MCh) challenges to assess bronchial responsiveness. Results: While PEEP influenced baseline respiratory mechanics, EELV and blood gas parameters (p < 0.001), no between-group differences were observed (p > 0.10). Conversely, significantly lower doses of MCh were required to achieve the same elevation in Raw under ketamine-xylazine anaesthesia compared to the other groups. Conclusion: In the most frequent rodent model of respiratory disorders, no differences in baseline respiratory mechanics or function were observed between commonly used anaesthesia regimes. Bronchial hyperresponsiveness in response to ketamine-xylazine anaesthesia should be considered when designing experiments using this regime. The findings of the present study indicate commonly used anaesthetic regimes allow fair comparison of respiratory mechanics in experimental animals undergoing any of the examined anaesthesia protocols.

Effects of Remimazolam and Propofol on Emergence Agitation in Elderly Patients Undergoing Hip Replacement: A Clinical, Randomized, Controlled Study

Purpose

The aim of this study was to compare the effects of remimazolam and propofol on emergence agitation (EA) in elderly patients undergoing hip replacement.

Methods

A total of 60 elderly patients undergoing hip replacement were recruited for this prospective, single-center, clinical, randomized, controlled study from February to April 2023. They were randomly assigned to two groups: the remimazolam group (group R) and the propofol group (group P). In group R, remimazolam was administered intravenously during the induction and maintenance of anesthesia, In group P, propofol was used during the induction and maintenance of anesthesia. The incidence of EA was recorded as the primary indicator. Secondary indicators included heart rate (HR) and mean arterial pressure (MAP) values at the following moments: 5 min prior to anesthetic induction (T0), 1 min following induction (T1), 5 min after the laryngeal mask was inserted (T2), the beginning of surgery (T3), the moment the laryngeal mask was removed (T4), and the overall incidence of postoperative adverse events (bleeding or splitting of the surgical incision, removal of the intravenous infusion needle, falling off the bed, hypoxemia, and hypertension).

Results

The incidence of EA was significantly lower in group R than in group P (10% vs 33%, P < 0.05). At T1, T2, and T3, the HR and MAP values of group R were higher than those of group P (P < 0.05). The overall incidence of postoperative adverse events was significantly lower in group R than in group P (P < 0.05).

Conclusion

Remimazolam further reduced the incidence of emergence agitation when compared to propofol during geriatric hip replacement. Moreover, it has a minor hemodynamic effect and lower the incidence of postoperative adverse events.

A Molecular Toolbox of Positron Emission Tomography Tracers for General Anesthesia Mechanism Research

With appropriate radiotracers, positron emission tomography (PET) allows direct or indirect monitoring of the spatial and temporal distribution of anesthetics, neurotransmitters, and biomarkers, making it an indispensable tool for studying the general anesthesia mechanism. In this Perspective, PET tracers that have been recruited in general anesthesia research are introduced in the following order: 1) ¹¹C/¹⁸F-labeled anesthetics, i.e., PET tracers made from inhaled and intravenous anesthetics; 2) PET tracers targeting anesthesia-related receptors, e.g., neurotransmitters and voltage-gated ion channels; and 3) PET tracers for studying anesthesia-related neurophysiological effects and neurotoxicity. The radiosynthesis, pharmacodynamics, and pharmacokinetics of the above PET tracers are mainly discussed to provide a practical molecular toolbox for radiochemists, anesthesiologists, and those who are interested in general anesthesia.

Remimazolam Tosylate Combined with Low-Dose Propofol Improves Sedation and Safety in Hysteroscopy

BACKGROUND

Propofol is widely used for sedation of hysteroscopy. It can cause injection pain, respiratory depression, and hypotension. Remimazolam is a novel ultra-short-acting benzodiazepine. Clinical practice has found that the use of remimazolam alone often leads to body movement during hysteroscopy, which decreases the safety and comfort. Here this study is to investigate whether remimazolam combined with low-dose propofol can improve the sedation effect and safety of hysteroscopy.

PATIENTS AND METHODS

In this prospective, randomized, parallel-controlled trial, women (18 to 60 years) undergoing hysteroscopy were randomly assigned to receive propofol (Group P), remimazolam tosylate (Group R), or remimazolam tosylate plus propofol (Group RP). Intraoperative sedation depth was kept at the bispectral index (BIS) value of 40-60. 6 μg/kg alfentanil was used for analgesic before sedation. Intraoperative low pulse oxygen saturation (SpO2), body movement, injection pain, mean arterial pressure (MAP), heart rate (HR), and postoperative recovery time, dizziness, nausea and vomiting were recorded and compared.

RESULTS

From February to July 2022, 193 patients were recruited and randomly assigned to group P (n=64), group R (n=64), or group RP (n=65). There was no significant inter-group difference of the intraoperative BIS values. The incidence of low SpO2, injection pain, hypotension, and postoperative dizziness in group RP were less than that in group P, and had no significant difference from group R. The incidence of body movement in group RP was less than that in group R, and had no significant difference from group P. Postoperative recovery time of group RP was shorter than that of the other two groups. No significant inter-group difference in bradycardia, nausea and vomiting was observed.

CONCLUSION

Remimazolam tosylate combined with low dose of propofol improved sedation and safety in hysteroscopy, and may be a more ideal sedative method for hysteroscopy.

An intravenous anesthetic drug-propofol, influences the biological characteristics of malignant tumors and reshapes the tumor microenvironment: A narrative literature review

Malignant tumors are the second leading cause of death worldwide. This is a public health concern that negatively impacts human health and poses a threat to the safety of life. Although there are several treatment approaches for malignant tumors, surgical resection remains the primary and direct treatment for malignant solid tumors. Anesthesia is an integral part of the operation process. Different anesthesia techniques and drugs have different effects on the operation and the postoperative prognosis. Propofol is an intravenous anesthetic that is commonly used in surgery. A substantial number of studies have shown that propofol participates in the pathophysiological process related to malignant tumors and affects the occurrence and development of malignant tumors, including anti-tumor effect, pro-tumor effect, and regulation of drug resistance. Propofol can also reshape the tumor microenvironment, including anti-angiogenesis, regulation of immunity, reduction of inflammation and remodeling of the extracellular matrix. Furthermore, most clinical studies have also indicated that propofol may contribute to a better postoperative outcome in some malignant tumor surgeries. Therefore, the author reviewed the chemical properties, pharmacokinetics, clinical application and limitations, mechanism of influencing the biological characteristics of malignant tumors and reshaping the tumor microenvironment, studies of propofol in animal tumor models and its relationship with postoperative prognosis of propofol in combination with the relevant literature in recent years, to lay a foundation for further study on the correlation between propofol and malignant tumor and provide theoretical guidance for the selection of anesthetics in malignant tumor surgery.

Propofol protects against high glucose-mediated endothelial injury via inhibition of COX2 and iNOS expressions

Perioperative hyperglycemia is a common metabolic disorder in the clinic. Hyperglycemia, via upregulation of E74-like ETS transcription factor 3 (ELF3), induces cyclooxygenase 2 (COX2) and inducible nitric oxide synthase (iNOS) expressions, thus leading to endothelial apoptosis and vascular endothelial injury. Propofol is a widely used anesthetic. In the present study, we explored whether and how propofol protects against high glucose-induced COX2 and iNOS expressions in human umbilical vein endothelial cells (HUVECs). We found that high glucose level decreases cell viability and increases COX2 and iNOS expressions in HUVECs. Our data also indicated that ELF3 overexpression participates in high glucose-mediated cell viability reduction and high glucose-induced COX2 and iNOS expressions. Moreover, propofol treatment improves high glucose-mediated reduction in cell viability and decreases COX2 and iNOS expressions via inhibition of ELF3 expressions. Furthermore, specificity protein 1 (SP1) was found to regulate ELF3 expression, thus mediating endothelial injury. Propofol inhibits high glucose-induced SP1 expression. High glucose increases the abundance of SP1 bound to the ELF3 promoter, which can be reversed by propofol treatment. The protective effect of propofol is reversed by SP1 overexpression. In conclusion, propofol downregulates high glucose-induced SP1 expression, thus attenuating high glucose-induced ELF3 expression, inhibiting high glucose-induced COX2 and iNOS expressions, and improving high glucose-mediated cell viability reduction in HUVECs.