Propofol Anesthesia Research Articles

Comparison of the bispectral indices of patients receiving remimazolam and propofol for general anesthesia: a randomized crossover trial

BackgroundRemimazolam is a safe and effective new benzodiazepine sedative that has unique advantages in anesthesia induction and maintenance. The differences in the electroencephalogram bispectral index (BIS) during general anesthesia between propofol and remimazolam deserve further exploration. MethodsSingle-center randomized crossover study. Patients who required multiple hysteroscopic surgery were randomly assigned to use remimazolam (0.27 mg/kg for induction and 1 mg/kg/h for maintenance) first and then propofol (2.0 mg/kg for induction and 6 mg/kg/h for maintenance) during hysteroscopic surgery again 3 months later, or in the opposite order. Both drugs were used at the latest ED95 for unconsciousness. The BIS values (primary endpoint), intraoperative conditions, and incidence of adverse reactions (secondary endpoints) were compared at each time point. BIS values were analyzed with a mixed model of repeated measurements (MMRM). ResultsSeventeen patients completed the study. The lowest BIS value in the remimazolam regimen was significantly higher than that in the propofol regimen (p = 0.001). The MMRM analysis of the BIS values revealed significant differences between the regimens at each time point (p < 0.001). The intraoperative diastolic blood pressure and heart rate changes were smaller, the recovery was faster, and there were fewer adverse reactions and less injection pain, but a greater incidence of intraoperative body movement and hiccups, in the remimazolam regimen. ConclusionThe trial indicated that remimazolam maintained a higher BIS level than propofol. The correlation between the BIS and the depth of anesthesia induced by remimazolam needs to be further studied. Trial registrationThis trial is registered at ClinicalTrials.gov: ChiCTR2200064551

Adverse Drug Events Observed with the Newly Approved Remimazolam in Comparison to Propofol for General Anesthesia in Patients Undergoing Surgery: A Meta-analysis.

Developments in anesthetic pharmacology have been aiming at minimizing physiological disturbance in addition to maintaining and improving titrateability, recovery profile, and patient experience. Remimazolam, a GABAAlpha receptor agonist, is a new intravenous anesthetic agent which has recently been approved for use. This analysis aimed to systematically compare the adverse drug events reported with the newly approved remimazolam in comparison to propofol for general anesthesia (GA) in patients undergoing surgery. Electronic databases were searched from 15 May to 20 December 2023 for relevant publications which compared the outcomes reported with the newly approved remimazolam versus propofol in patients undergoing surgery. Relevant reported adverse drug events were the endpoints of this study. The statistical analysis was carried out using the latest version of the RevMan software. Data analysis was represented by risk ratio (RR) with 95% confidence intervals (CI). Sixteen studies with a total number of 1897 participants were included in this analysis; 1104 participants received remimazolam and 793 participants received propofol. The risks for hypotension (RR 0.50, 95%CI 0.43-0.58; P = 0.00001), hypoxemia (RR 0.43, 95%CI 0.19-0.99; P = 0.05), bradycardia (RR 0.53, 95%CI 0.36-0.78; P = 0.001), pain at injection site (RR 0.07, 95%CI 0.01-0.56; P = 0.01), and total adverse events (RR 0.33, 95%CI 0.24-0.47; P = 0.00001) were significantly lower with remimazolam. However, no significant differences were observed in terms of postoperative nausea and vomiting (RR 0.98, 95%CI 0.66-1.46; P = 0.93), dizziness (RR 0.42, 95%CI 0.11-1.57; P = 0.20), psychiatric symptoms (RR 1.09, 95%CI 0.45-2.67; P = 0.85), and respiratory depression (RR 0.81, 95%CI 0.24-2.76; P = 0.74). Our current analysis showed that the newly approved remimazolam was apparently associated with significantly fewer adverse drug events in comparison to propofol for GA in patients undergoing surgery. Therefore, this new drug should be further studied and more research with larger population sizes should be carried out to confirm this hypothesis.

Local orchestration of distributed functional patterns supporting loss and restoration of consciousness in the primate brain

A central challenge of neuroscience is to elucidate how brain function supports consciousness. Here, we combine the specificity of focal deep brain stimulation with fMRI coverage of the entire cortex, in awake and anaesthetised non-human primates. During propofol, sevoflurane, or ketamine anaesthesia, and subsequent restoration of responsiveness by electrical stimulation of the central thalamus, we investigate how loss of consciousness impacts distributed patterns of structure-function organisation across scales. We report that distributed brain activity under anaesthesia is increasingly constrained by brain structure across scales, coinciding with anaesthetic-induced collapse of multiple dimensions of hierarchical cortical organisation. These distributed signatures are observed across different anaesthetics, and they are reversed by electrical stimulation of the central thalamus, coinciding with recovery of behavioural markers of arousal. No such effects were observed upon stimulating the ventral lateral thalamus, demonstrating specificity. Overall, we identify consistent distributed signatures of consciousness that are orchestrated by specific thalamic nuclei.

Efficacy and safety of ciprofol versus propofol for anesthesia induction in adult patients received elective surgeries: a meta‑analysis

BackgroundPropofol is use widely used in anesthesia, known for its effectiveness, may lead to cardiopulmonary issues in some patients. Ciprofol has emerged as a possible alternative to propofol because it can achieve comparable effects to propofol while causing fewer adverse events at lower doses. However, no definitive conclusion has been reached yet. This meta-analysis aimed to evaluate the efficacy and safety of ciprofol versus propofol in adult patients undergoing elective surgeries under general anesthesia.MethodsWe searched PubMed, EMBASE, the Cochrane library, Web of Science, and Chinese National Knowledge Infrastructure (CNKI) to identify potentially eligible randomized controlled trials (RCT) comparing ciprofol with propofol in general anesthesia until September 30, 2023. The efficacy outcomes encompassed induction success rate, time to onset of successful induction, time to disappearance of eyelash reflex, and overall estimate means in Bispectral Index (BIS). Safety outcomes were assessed through time to full alertness, incidence of hypotension, incidence of arrhythmia, and incidence of injection-site pain. Continuous variables were expressed as mean difference (MD) with 95% confidence interval (CI), and dichotomous variables were expressed as risk ratio (RR) with 95% CI. Statistical analyses were performed using RevMan 5.4 and STATA 14.0. The quality of the evidence was rated through the grading of recommendations, assessment, development and evaluation (GRADE) system.ResultsA total of 712 patients from 6 RCTs were analyzed. Meta-analysis suggested that ciprofol was equivalent to propofol in terms of successful induction rate, time to onset of successful induction, time to disappearance of eyelash reflex, time to full alertness, and incidence of arrhythmia, while ciprofol was better than propofol in overall estimated mean in BIS (MD: -3.79, 95% CI: -4.57 to -3.01, p < 0.001), incidence of hypotension (RR: 0.63, 95% CI: 0.42 to 0.94, p = 0.02), and incidence of injection-site pain (RR: 0.26, 95% CI: 0.14 to 0.47, p < 0.001). All results were supported by moderate to high evidence.ConclusionsCiprofol may be a promising alternative to propofol because it facilitates achieving a satisfactory anesthesia depth and results in fewer hypotension and injection-site pain. However, we still recommend conducting more studies with large-scale studies to validate our findings because only limited data were accumulated in this study.Trial registrationPROSPERO 2023 CRD42023479767.

Safety and efficacy comparison of remimazolam and propofol for intravenous anesthesia during gastroenteroscopic surgery of older patients: A meta-analysis

BACKGROUND Remimazolam is characterized by rapid action and inactive metabolites. It is used as the general anesthetic for many clinical surgeries. In this study, we performed a meta-analysis to evaluate whether remimazolam is superior to propofol for gastroenteroscopy in older patients. AIM To compare the adverse events and efficacy of remimazolam and propofol during gastroenteroscopy in older adults. METHODS The PubMed, Web of Science, the Cochrane Library databases were queried for the relevant key words "remimazolam,” "and propofol,” "and gastrointestinal endoscopy or gastroscopy.” The search scope was "Title and Abstract,” and the search was limited to human studies and publications in English. Seven studies wherein remimazolam and propofol were compared were included for the meta-analysis. RESULTS We selected seven randomized controlled trials involving 1445 cases for the analysis. Remimazolam reduced the hypotension (relative risk, RR = 0.44, 95%CI: 0.29-0.66, P = 0.000), respiratory depression (RR = 0.46, 95%CI: 0.30-0.70, P = 0.000), injection pain (RR = 0.12, 95%CI: 0.05-0.25, P = 0.000), bradycardia (RR = 0.37, 95%CI: 0.24-0.58, P = 0.000), and time to discharge [weighted mean difference (WMD) = -0.58, 95%CI: -0.97 to -0.18, P = 0.005], compared to those after propofol administration. No obvious differences were observed for postoperative nausea and vomiting (RR = 1.09, 95%CI: 0.97-1.24, P = 0.151), dizziness (RR = 0.77, 95%CI: 0.43-1.36, P = 0.361), successful sedation rate (RR = 0.96, 95%CI: 0.93-1.00, P = 0.083), or the time to become fully alert (WMD = 0.00, 95%CI: -1.08-1.08, P = 0.998). CONCLUSION Remimazolam appears to be safer than propofol for gastroenteroscopy in older adults. However, further studies are required to confirm these findings.

External validation of the modified Marsh and Schnider models for medium-chain triglyceride propofol in target-controlled infusion anesthesia

BackgroundPropofol formulated with medium- and long-chain triglycerides (MCT/LCT propofol) has rapidly replaced propofol formulated with long-chain triglycerides (LCT propofol). Despite this shift, the modified Marsh and Schnider pharmacokinetic models developed using LCT propofol are still widely used for target-controlled infusion (TCI) of propofol. This study aimed to validate the external applicability of these models by evaluating their predictive performance during TCI of MCT/LCT propofol in general anesthesia.MethodsAdult patients (n = 48) undergoing elective surgery received MCT/LCT propofol via a TCI system using either the modified Marsh or Schnider models. Blood samples were collected at various target propofol concentrations and at specific time points, including the loss of consciousness and the recovery of consciousness (13 samples per patient). The actual plasma concentration of propofol was determined using high-performance liquid chromatography. The predictive performance of each pharmacokinetic model was assessed by calculating four parameters: inaccuracy, bias, divergence, and wobble.ResultsBoth the modified Marsh and Schnider models demonstrated predictive performances within clinically acceptable ranges for MCT/LCT propofol. The inaccuracy values were 24.4% for the modified Marsh model and 26.9% for the Schnider model. Both models showed an overall positive bias, 16.4% for the modified Marsh model and 16.6% for the Schnider model. The predictive performance of MCT/LCT propofol was comparable to that of LCT propofol, suggesting formulation changes might exert only a minor impact on the reliability of the TCI system during general anesthesia. Additionally, both models exhibited higher bias and inaccuracy at target concentrations ranging from 3.5 ~ 5 ug/ml than at concentrations between 2 ~ 3 ug/ml.ConclusionsThe modified Marsh and Schnider models, initially developed for LCT propofol, remain clinically acceptable for TCI with MCT/LCT propofol.Trial registrationThis study was registered at the Clinical Research Information Service of the Korean National Institute of Health (https://cris.nih.go.kr; registration number: KCT0002191; 06/01/2017).

Clinico-Physiological and Haemodynamic Alterations Following Propofol Induction and Premedication with Butorphanol, Dexmedetomidine or Acepromazine in Dogs

The present study was conducted during February-October 2021 at Department of Veterinary Surgery and Radiology, College of Veterinary Science &amp; A.H. Anjora, Durg (C.G.), India to evaluate the alternations on clinico-physiological and haemodynamic parameters following propofol induction in dogs premedicated with butorphanol or dexmedetomidine or acepromazine. Eighteen adult dogs of either sex were randomly divided into three groups (BP, DP and AP) with six animals in each. Ten minutes prior to the anaesthetic administration, all the dogs were administered glycopyrrolate @ 0.02 mg kg-1 I/M. The animals of group BP, DP and AP were premedicated intramuscularly with butorphanol @ 0.3 mg kg-1 b.wt., dexmedetomidine @ 10 µg kg-1 b.wt. and acepromazine @ 0.4 mg kg-1 b.wt. respectively. General anaesthesia was induced with propofol @ 7 mg kg-1 b.wt. intravenously. Clinical parameters were recorded following induction with propofol. Physiological and haemodynamic parameters were recorded before (0), 5 min. after sedation, induction and at 10, 20, 40, 60 and 120 min. post propofol anaesthesia. The onset of sedation and anaesthesia was quicker in group DP followed by AP and BP. Duration of anaesthesia and complete recovery were significantly (p&lt;0.05) longer in group DP as compared to group BP and AP. The physiological and haemodynamic parameters showed transient changes which were compensated and remained within normal range during the study period without producing any deleterious effect. Thus, propofol can be safely used as induction agent in dogs premedicated with either dexmedetomidine or butorphanol or acepromazine and does not produce any adverse effect on cardiopulmonary system. However, dexmedetomidine-propofol combination provided longer duration of anaesthesia in dogs as compared to other groups.

Effect of remifentanil on three effect-site concentrations of propofol and their relationship during electroencephalography at loss of response, at maximum alpha power, and at onset of burst suppression: a prospective randomized trial.

The effect-site concentration (Ce) at loss of response (Ce-LOR) to propofol closely correlates both with Ce as electroencephalographic alpha power becomes highest (Ce-alpha) and with Ce at onset of burst suppression (BS) (Ce-OBS), when no opioids are administered. Co-administration of opioids dose-dependently decreases Ce-LOR. We investigated the influence of remifentanil on the relationship between these three Ces. After receiving approval from our local ethical committee, with written informed consent, we enrolled 90 participants (ASA-PS I or II) who were scheduled for elective surgery. Participants were randomly assigned to three groups: constant remifentanil Ce 0ng/ml (Remi_0); 1ng/mL (Remi_1); and 2ng/mL (Remi_2). We recorded both raw EEG and EEG-derived parameters on a computer. After reaching remifentanil equilibrium, we administered propofol using a target-controlled infusion pump such that propofol Ce increased to about 0.3μg/mL/min. After determining Ce-LOR, we administered 0.6mg/kg of rocuronium and started mask ventilation. The study protocol ended after observation of BS. Three participants were excluded. Ce-LOR in each group (Remi_0, Remi_1, Remi_2) was 2.00 ± 0.58μg/mL, 1.43 ± 0.49μg/mL, and 1.37 ± 0.42μg/mL. Ce-alpha was 2.91 ± 0.63μg/mL, 2.30 ± 0.41μg/mL, and 2.12 ± 0.39μg/mL. Ce-OBS was 3.80 ± 0.69μg/mL, 3.25 ± 0.68μg/mL, and 2.90 ± 0.57μg/mL. In three other instances, Ce was decreased by remifentanil. Generalized linear model analysis revealed that remifentanil had no influence on the relationship between the three Ces. During propofol anesthesia, even low concentrations of remifentanil shifted concentration-related electroencephalographic changes.

Study protocol: Cerebral characterization of sensory gating in disconnected dreaming states during propofol anesthesia using fMRI.

Disconnected consciousness describes a state in which subjective experience (i.e., consciousness) becomes isolated from the external world. It appears frequently during sleep or sedation, when subjective experiences remain vivid but are unaffected by external stimuli. Traditional methods of differentiating connected and disconnected consciousness, such as relying on behavioral responsiveness or on post-anesthesia reports, have demonstrated limited accuracy: unresponsiveness has been shown to not necessarily equate to unconsciousness and amnesic effects of anesthesia and sleep can impair explicit recollection of events occurred during sleep/sedation. Due to these methodological challenges, our understanding of the neural mechanisms underlying sensory disconnection remains limited. To overcome these methodological challenges, we employ a distinctive strategy by combining a serial awakening paradigm with auditory stimulation during mild propofol sedation. While under sedation, participants are systematically exposed to auditory stimuli and questioned about their subjective experience (to assess consciousness) and their awareness of the sounds (to evaluate connectedness/disconnectedness from the environment). The data collected through interviews are used to categorize participants into connected and disconnected consciousness states. This method circumvents the requirement for responsiveness in assessing consciousness and mitigates amnesic effects of anesthesia as participants are questioned while still under sedation. Functional MRI data are concurrently collected to investigate cerebral activity patterns during connected and disconnected states, to elucidate sensory disconnection neural gating mechanisms. We examine whether this gating mechanism resides at the thalamic level or results from disruptions in information propagation to higher cortices. Furthermore, we explore the potential role of slow-wave activity (SWA) in inducing disconnected consciousness by quantifying high-frequency BOLD oscillations, a known correlate of slow-wave activity. This study represents a notable advancement in the investigation of sensory disconnection. The serial awakening paradigm effectively mitigates amnesic effects by collecting reports immediately after regaining responsiveness, while still under sedation. Ultimately, this research holds the potential to understand how sensory gating is achieved at the neural level. These biomarkers might be relevant for the development of sensitive anesthesia monitoring to avoid intraoperative connected consciousness and for the assessment of patients suffering from pathologically reduced consciousness. European Union Drug Regulating Authorities Clinical Trials Database (EudraCT), identifier 2020-003524-17.

The Application of Propofol Combined with Remifentanil and LMA in Laparoscopic Ovarian Cystectomy

Introduction: The application of Propofol combined with Remifentanil and Laryngeal Mask Airway (LMA) in laparoscopic ovarian cystectomy represents a significant advancement in the field of anesthetic techniques for minimally invasive gynecological surgeries. Aim of the study: The aim of this study was to evaluate the application of propofol combined with remifentanil and LMA in laparoscopic ovarian cystectomy. Methods: This cross-sectional study at North Bengal Medical Colleges and Bogura Medical College, Bangladesh from January 2015 - December 2018, included 120 female patients undergoing laparoscopic ovarian cystectomy. They were split into two groups of 60: Group A received remifentanil with propofol, and Group B received fentanyl with propofol for anesthesia, with LMA used in all cases. Result: There were no statistically significant difference (p&gt;0.05) between the study groups in demographic characteristics. ASA grades I-III distributed comparably (p-values 0.6035 to 0.8529). Group-A had a shorter surgical time and less blood loss compared to Group-B. Hospital stay was shorter for Group-A than Group-B. Notably, Group-A showed significantly (p≤0.05) better anesthesia induction and recovery times, and higher OAAS scores, indicating quicker recovery. Group-A also reported significantly (p≤0.05) lower VAS scores for pain at various post-operation intervals, suggesting better pain management. Complications like nausea, pruritus, vomiting, and abdominal pain were slightly higher in Group-B, except for sore throat, which was equal in both groups. Conclusion: The use of propofol combined with remifentanil and Laryngeal Mask Airway for laparoscopic ovarian cystectomy has better anesthetic management, quicker recovery, more effective pain control, and fewer complications.

Comparing the Analgesic Effects Between the Pre- and Post-costal Cartilage Harvest Cohorts Using Ultrasound-Guided Deep Serratus Anterior Plane Block in Children with Microtia Undergoing Auricular Reconstruction: A Randomized Clinical Trial.

Pain following costal cartilage harvest surgery is the most common complaint of auricular reconstruction (AR). Anesthesiologists are continuously searching for an effective postoperative pain control method. This study was conducted from 10 April 2022 to 10 June 2022. Sixty children undergoing AR using costal cartilage were randomly assigned to either a serratus anterior plane block performed before costal cartilage harvest (SAPB-pre-cohort; n=30) or the SAPB-post-cohort (Post-costal cartilage Harvest Cohort: n=30). The primary endpoint measures were the Numerical Rating Scale (NRS) scores of the chest and ear pain degrees recorded at 1-, 6-, 12-, 24-, and 48-h after surgery. Intraoperative anesthetic and analgesic dosages, sufentanil consumption and rescue analgesia consumption during the first 24h post-operation, cough score during extubation, extubation agitation score, length of stay, the extubation time, first ambulatory time, analgesia duration, and opioid-related adverse effects and SAPB-related adverse effects were the secondary endpoints. The rest and coughing NRS scores were significantly reduced in the SAPB-pre-cohort 6 and 12h post-operation in comparison with the SAPB-post-cohort (rest 6h p=0.002, others p<0.001). No significant difference in the NRS ear scores existed between the two cohorts (p>0.05). The use of propofol and remifentanil for general anesthesia during the SAPB-pre-procedure was significantly reduced compared to the SAPB-post-group, with statistical significance (p<0.001). Sufentanil consumption and rescue analgesia consumption were significantly reduced in the SAPB-pre-cohort (p=0.001, p=0.033). The extubation time and first ambulatory time were markedly shorter in the SAPB-pre-cohort (all p<0.001). Analgesia duration was markedly longer in the SAPB-pre-cohort (p<0.001). No significant differences were noted in the cough score during extubation, extubation agitation score, length of stay between the two cohorts (all p>0.05). Opioid-related adverse effects occurred more in the SAPB-post-cohort, while there was no statistical significance (16.7 vs. 36.7%; p=0.082). There were no blockade-related complications observed in either cohort. The analgesic effect of the SAPB-pre-cohort was better than the SAPB-post-cohort suggesting both efficacy and feasibility of preemptive analgesia. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Sevoflurane Postconditioning Protects From an Early Neurological Deficit After Subarachnoid Hemorrhage: Results of a Randomized Laboratory Study in Rats.

Subarachnoid hemorrhage (SAH) is associated with neurocognitive impairment. Recent data suggest that sevoflurane attenuates edema formation after SAH in rats. However, so far, no information is available about the long-term repair phase, nor if sevoflurane impacts functionality by increasing vascularity. This study tested whether sevoflurane postconditioning would improve long-term neurologic deficit through increased formation of new vessels close to the hemorrhage area. Fifty-three animals were subjected to SAH or sham surgery with or without a 2-hour sevoflurane postconditioning (versus propofol anesthesia). Animal survival, including dropout animals due to death or reaching termination criteria, as well as neurologic deficit, defined by the Garcia score, were assessed 2 hours after recovery until postoperative day 14. On day 14, blood samples and brain tissue were harvested. Vessel density was determined by the number of cluster of differentiation 31 (CD31)-positive vessels, and activated glial cells by glial fibrillary acidic protein (GFAP)-positive astrocytes per field of view. The survival rate for sham animals was 100%, 69% in the SAH-propofol and 92% in the SAH-sevoflurane groups. According to the log-rank Mantel-Cox test, survival curves were significantly different (P = .024). The short-term neurologic deficit was higher in SAH-propofol versus SAH-sevoflurane animals 2 hours after recovery and on postoperative day 1 (propofol versus sevoflurane: 14. 6 ± 3.4 vs 15. 9 ± 2.7 points, P = .034, and 16. 2 ± 3.5 vs 17. 8 ± 0.9 points, P = .015). Overall complete recovery from neurologic deficit was observed on day 7 in both SAH groups (18. 0 ± 0.0 vs 18. 0 ± 0.0 points, P = 1.000). Cortical vascular density increased to 80. 6 ± 15.0 vessels per field of view in SAH-propofol animals (vs 71. 4 ± 10.1 in SAH-sevoflurane, P < .001). Activation of glial cells, an indicator of neuroinflammation, was assessed by GFAP-positive astrocytes GFAP per field of view. Hippocampal GFAP-positive cells were 201 ± 68 vs 179 ± 84 cells per field of view in SAH-propofol versus SAH-sevoflurane animals (P < .001). Sevoflurane postconditioning improves survival by 23% (SAH-sevoflurane versus SAH-propofol). The sevoflurane intervention could attenuate the early neurologic deficit, while the long-term outcome was similar across the groups. A higher vascular density close to the SAH area in the propofol group was not associated with improved outcomes.

Propofol Reversibly Attenuates Short-Range Microstate Ordering and 20Hz Microstate Oscillations.

Microstate sequences summarize the changing voltage patterns measured by electroencephalography, using a clustering approach to reduce the high dimensionality of the underlying data. A common approach is to restrict the pattern matching step to local maxima of the global field power (GFP) and to interpolate the microstate fit in between. In this study, we investigate how the anesthetic propofol affects microstate sequence periodicity and predictability, and how these metrics are changed by interpolation. We performed two frequency analyses on microstate sequences, one based on time-lagged mutual information, the other based on Fourier transform methodology, and quantified the effects of interpolation. Resting-state microstate sequences had a 20Hz frequency peak related to dominant 10Hz (alpha) rhythms, and the Fourier approach demonstrated that all five microstate classes followed this frequency. The 20Hz periodicity was reversibly attenuated under moderate propofol sedation, as shown by mutual information and Fourier analysis. Characteristic microstate frequencies could only be observed in non-interpolated microstate sequences and were masked by smoothing effects of interpolation. Information-theoretic analysis revealed faster microstate dynamics and larger entropy rates under propofol, whereas Shannon entropy did not change significantly. In moderate sedation, active information storage decreased for non-interpolated sequences. Signatures of non-equilibrium dynamics were observed in non-interpolated sequences, but no changes were observed between sedation levels. All changes occurred while subjects were able to perform an auditory perception task. In summary, we show that low dose propofol reversibly increases the randomness of microstate sequences and attenuates microstate oscillations without correlation to cognitive task performance. Microstate dynamics between GFP peaks reflect physiological processes that are not accessible in interpolated sequences.

Impact of propofol and sevoflurane anesthesia on cognition and emotion in gastric cancer patients undergoing radical resection.

Propofol and sevoflurane are commonly used anesthetic agents for maintenance anesthesia during radical resection of gastric cancer. However, there is a debate concerning their differential effects on cognitive function, anxiety, and depression in patients undergoing this procedure. To compare the effects of propofol and sevoflurane anesthesia on postoperative cognitive function, anxiety, depression, and organ function in patients undergoing radical resection of gastric cancer. A total of 80 patients were involved in this research. The subjects were divided into two groups: Propofol group and sevoflurane group. The evaluation scale for cognitive function was the Loewenstein occupational therapy cognitive assessment (LOTCA), and anxiety and depression were assessed with the aid of the self-rating anxiety scale (SAS) and self-rating depression scale (SDS). Hemodynamic indicators, oxidative stress levels, and pulmonary function were also measured. The LOTCA score at 1 d after surgery was significantly lower in the propofol group than in the sevoflurane group. Additionally, the SAS and SDS scores of the sevoflurane group were significantly lower than those of the propofol group. The sevoflurane group showed greater stability in heart rate as well as the mean arterial pressure compared to the propofol group. Moreover, the sevoflurane group displayed better pulmonary function and less lung injury than the propofol group. Both propofol and sevoflurane could be utilized as maintenance anesthesia during radical resection of gastric cancer. Propofol anesthesia has a minimal effect on patients' pulmonary function, consequently enhancing their postoperative recovery. Sevoflurane anesthesia causes less impairment on patients' cognitive function and mitigates negative emotions, leading to an improved postoperative mental state. Therefore, the selection of anesthetic agents should be based on the individual patient's specific circumstances.

Propofol-induced anesthesia involves the direct inhibition of glutamatergic neurons in the lateral hypothalamus.

Propofol is the most widely used intravenous general anesthetic; however, the neuronal circuits that mediate its anesthetic effects are still poorly understood. Glutamatergic neurons in the lateral hypothalamus have been reported to be involved in maintenance of arousal and consciousness. Using Vglut2-Cre transgenic mice, we recorded this group of cells specifically and found that propofol can directly inhibit the glutamatergic neurons, and enhance inhibitory synaptic inputs on these cells, thereby reducing neuronal excitability. Through chemogenetic interventions, we found that inhibition of these neurons increased the duration of propofol-induced anesthesia and reduced movement in the animals after the recovery of right reflex. In contrast, activating this group of cells reduced the duration of propofol anesthesia and increased the animals' locomotor activity after the recovery of right reflex. These results suggest that propofol-induced anesthesia involves the inhibition of glutamatergic neurons in the lateral hypothalamus.

Dose-dependent changes in orientation amplitude maps in the cat visual cortex after propofol bolus injections

A general intravenous anesthetic propofol (2,6-diisopropylphenol) is widely used in clinical, veterinary practice and animal experiments. It activates gamma- aminobutyric acid (GABAa) receptors. Though the cerebral cortex is one of the major targets of propofol action, no study of dose dependency of propofol action on cat visual cortex was performed yet. Also, no such investigation was done until now using intrinsic signal optical imaging. Here, we report for the first time on the dependency of optical signal in the visual cortex (area 17/area 18) on the propofol dose. Optical imaging of intrinsic responses to visual stimuli was performed in cats before and after propofol bolus injections at different doses on the background of continuous propofol infusion. Orientation amplitude maps were recorded. We found that amplitude of optical signal significantly decreased after a bolus dose of propofol. The effect was dose- and time-dependent producing stronger suppression of optical signal under the highest bolus propofol doses and short time interval after injection. In each hemisphere, amplitude at cardinal and oblique orientations decreased almost equally. However, surprisingly, amplitude at cardinal orientations in the ipsilateral hemisphere was depressed stronger than in contralateral cortex at most time intervals. As the magnitude of optical signal represents the strength of orientation tuned component, these our data give new insights on the mechanisms of generation of orientation selectivity. Our results also provide new data toward understanding brain dynamics under anesthesia and suggest a recommendation for conducting intrinsic signal optical imaging experiments on cortical functioning under propofol anesthesia.

Propofol-based total intravenous anesthesia is associated with less postoperative recurrence than desflurane anesthesia in thyroid cancer surgery.

The effects of anesthesia in patients undergoing thyroid cancer surgery are still not known. We investigated the relationship between the type of anesthesia and patient outcomes following elective thyroid cancer surgery. This was a retrospective cohort study of patients who underwent elective surgical resection for papillary thyroid carcinoma between January 2009 and December 2019. Patients were grouped according to the type of anesthesia they received, desflurane or propofol. A Kaplan-Meier analysis was conducted, and survival/recurrence curves were presented from the date of surgery to death/recurrence. Univariable and multivariable Cox regression models were used to compare hazard ratios for recurrence after propensity matching. A total of 621 patients (22 deaths, 3.5%) under desflurane anesthesia and 588 patients (32 deaths, 5.4%) under propofol anesthesia were included. Five hundred and eighty-eight patients remained in each group after propensity matching. Propofol anesthesia was not associated with better survival compared to desflurane anesthesia in the matched analysis (P = 0.086). However, propofol anesthesia was associated with less recurrence (hazard ratio, 0.38; 95% confidence interval, 0.25-0.56; P < 0.001) in the matched analysis. Propofol anesthesia was associated with less recurrence, but not mortality, following surgery for papillary thyroid carcinoma than desflurane anesthesia. Further prospective investigation is needed to examine the influence of propofol anesthesia on patient outcomes following thyroid cancer surgery.

Criticality supports cross-frequency cortical-thalamic information transfer during conscious states.

Consciousness is thought to be regulated by bidirectional information transfer between the cortex and thalamus, but the nature of this bidirectional communication - and its possible disruption in unconsciousness - remains poorly understood. Here, we present two main findings elucidating mechanisms of corticothalamic information transfer during conscious states. First, we identify a highly preserved spectral channel of cortical-thalamic communication that is present during conscious states, but which is diminished during the loss of consciousness and enhanced during psychedelic states. Specifically, we show that in humans, mice, and rats, information sent from either the cortex or thalamus via δ/θ/α waves (∼1-13 Hz) is consistently encoded by the other brain region by high γ waves (52-104 Hz); moreover, unconsciousness induced by propofol anesthesia or generalized spike-and-wave seizures diminishes this cross-frequency communication, whereas the psychedelic 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) enhances this low-to-high frequency interregional communication. Second, we leverage numerical simulations and neural electrophysiology recordings from the thalamus and cortex of human patients, rats, and mice to show that these changes in cross-frequency cortical-thalamic information transfer may be mediated by excursions of low-frequency thalamocortical electrodynamics toward/away from edge-of-chaos criticality, or the phase transition from stability to chaos. Overall, our findings link thalamic-cortical communication to consciousness, and further offer a novel, mathematically well-defined framework to explain the disruption to thalamic-cortical information transfer during unconscious states.

Dreaming during gastrointestinal endoscopy under propofol, ciprofol, or remimazolam anesthesia: study protocol for a parallel-design double-blind, single-center trial

BackgroundDreaming sometimes occurs during sedation. It has been reported that factors such as different anesthetics, depth of anesthesia, age, sex, and preoperative psychological state may affect dreams. Ciprofol and remimazolam are novel choices for painless endoscopy. Herein, we aimed to investigate dreaming during gastrointestinal endoscopy under propofol, ciprofol, and remimazolam anesthesia respectively.MethodsThis is a prospective, parallel-design double-blind, single-center clinical trial. Three hundred and sixty subjects undergoing elective painless gastroscopy, colonoscopy, or gastroenteroscopy will be enrolled. Eligible subjects will undergo propofol-, ciprofol-, or remimazolam-induced anesthesia to finish the examination. Interviews about the modified Brice questionnaire will be conducted in the recovery room. Incidence of dreaming is set as the primary outcome. Secondary outcomes include type of dreams, improvement of sleep quality, evaluation of patients, incidence of insufficient anesthesia, and intraoperative awareness. Safety outcomes are the incidences of hypotension and hypoxia during examination and adverse events during recovery.DiscussionThis study may observe different incidences of dreaming and diverse types of dreams, which might lead to different evaluations to the anesthesia procedure. Based on the coming results, anesthesiologists can make a better medication plan for patients who are going to undergo painless diagnosis and treatment.Trial registrationThis trial was registered at the Chinese Clinical Trial Registry on May 18, 2023 (registration number ChiCTR2300071565).

Comparative Haematological Responses in Rumenotomy: Impact of Diazepam and Xylazine Pre-medication in West African Dwarf Goats Undergoing Propofol Anaesthesia

Aim:In small ruminant surgery, an understanding of the haematological responses to different anesthetic protocols is crucial for optimizing post-operative outcomes. In this study, the haematological responses of West African Dwarf (WAD) goats undergoing rumenotomy under different anaesthetic protocols were investigated. Methods:Goats were categorized into three groups: Group A received Diazepam pre-medication and Propofol anesthesia, Group B received xylazine pre-medication and Propofol anesthesia, while Group C served as a control with only Propofol anesthesia during rumenotomy. Blood samples were collected at various time points post-rumenotomy for hematological analyses. Results: Results revealed no significant (P&gt;0.05) differences in the packed cell volume (PCV) between groups, except at 24 hours post-surgery where Group A had a higher PCV than in Groups B and C. Haemoglobin (Hb) and total red blood cell count (TRBC) showed no significant (P&gt;0.05) differences across all groups throughout the study. Total white blood cell count (TWBC) did not differ pre-surgery, but Group A displayed a significant increase immediately and 24 hours post-surgery. Neutrophil counts in Group A were elevated during intra-surgery and up to 48 hours post-surgery compared to Groups B and C. The lymphocyte count in Group A was significantly decreased immediately post-surgery. Conclusion:These findings highlight the impact of anaesthetic and pre-medication protocols on specific haematological parameters in WAD goats undergoing rumenotomy, thus, emphasizing the importance of considering these factors in surgical interventions for optimal postoperative outcomes. Hence, further research is recommended to elucidate the mechanisms associated with these haematological variations.