Depth Of Anesthesia Research Articles

Assessment of the sedative effect of various anesthetics in Coregonus Peled (Gmelin, 1789) in aquaculture

The sedative effect of four anesthetic agents in whitefish was studied. It is shown that the effect of anesthetics causes a number of consistent behavioral and physiological reactions in fish, reflecting the change in the state of their body. For most technological fish-breeding processes, it is necessary for fish to stay in a state of muscle relaxation while maintaining respiratory rhythm. These requirements are met by the sedation stage, which is observed with all types of anesthesia in peled. It has been established that the use of some of the tested drugs is incorrect in anesthesia in general in whitefish and in pelage in particular. Thus, the use of sodium thiopental is unacceptable, due to the uncontrolled suppression of the respiratory function of fish under the action of this agent. The use of lidocaine is characterized by prolonged induction, which does not correspond to the temporary norms of fish anesthesia. Among the tested drugs, propofol has sufficient anesthetic efficacy, which is confirmed by the temporary indicators of induction/ recovery, the depth and manageability of anesthesia, and low indicators of respiratory depression. Eugenol can serve as an alternative to propofol, which is cost-effective when working with mass material that requires large financial costs. In general, the choice of anesthetic and the adjustment of its doses depend on the specific task facing the fish breeder-ichthyopathologist.

Optimization of inhaled anesthesia for Octodon degus using electroencephalography.

Physiological responses to inhaled anesthetics vary among species. Therefore, a precise anesthetic technique is important for each individual species. In this study, we focused on the degu (Octodon degus), a small herbivorous rodent. Degus have recently begun to be used as laboratory models for brain research because of certain human-like characteristics, such as spontaneous development of Alzheimer's disease. In this study, we evaluated appropriate induction and maintenance anesthesia conditions for isoflurane and sevoflurane in degus by a stimulation test, electroencephalography (EEG), minimum alveolar concentration (MAC), and vital signs. During induction, more rapid time to loss of the righting reflex and deeper anesthesia in degus were observed in isoflurane. The MAC value for degus were 1.75 ± 0.0% in isoflurane and 2.25 ± 0.27% in sevoflurane. Whereas some degus were awake during maintenance anesthesia using both anesthetics at concentrations of ≤2%, no rats were awake when using sevoflurane at a concentration of 2%. The duration of the total flat EEG, a measure of the depth of maintenance anesthesia, was longer for isoflurane than for sevoflurane. Furthermore, higher concentrations of both anesthetics suppressed the respiratory rate in degus. These new findings regarding inhalation anesthesia in degus will contribute to future developments in the fields of laboratory animals and veterinary medicine.

Obezbeđivanje disajnog puta novorođenčadi i odojčadi - preporuke

Tracheal intubation is one of the most frequently performed medical procedures in neonatal intensive care units. Younger children, pre-term and full-term infants are at the highest risk of respiratory and traumatic complications when securing the airway. A difficult airway implies a clinical situation in which difficult airway management occurs by an experienced specialist. It is recommended to apply an adequate depth of sedation or general anesthesia with muscle relaxation in neonates and infants during the airway management in order to ensure the comfort and safety of the patients. The use of a videolaryngoscope with standard blades (Macintosh and Miller) is recommended for securing the airway, especially in neonates and infants. Use of passive oxygenation during tracheal intubation prolongs the safe duration of apnea, increases functional residual capacity and reduces the incidence of hypoxemia. The use of supraglottic airway device for rescue ventilation and oxygenation is advised if tracheal intubation has failed and ventilation with a face mask is inadequate. Limiting the number of tracheal intubation attempts is recommended. If two or fewer laryngoscopies are unsuccessful, operator should switch to indirect methods for intubation. After four attempts, intubators should stop and wake the child. It is advised to immediately check the position of the tube simultaneously with clinical signs and the appearance of sustainable carbon dioxide curve. Assessment of clinical indicators is necessary to predict successful awake extubation. A tidal volume greater than 5 ml/kg may indicate readiness for extubation.

An Entropy Based Observational Study to Assess the Dosage of Propofol Required for Induction of Anaesthesia by Varying the Time Intervals between Fentanyl and Propofol Administration

Background: Propofol is the preferred drug for the induction of anesthesia in many centers. However, its ubiquitous use is hampered by adverse effects. The rationale behind our study is to prove that whether the administration of an opioid drug before propofol induction, lowers the amount of propofol requirement for balanced anesthesia, and enhances hemodynamic stability. Aim: The present study intends to know the consequence of the differing time intervals between the administration of fentanyl and propofol on the dosage of propofol required to achieve induction of general anesthesia. Methods: In this observational study, 84 patients were included in the study. Patients who received propofol immediately after fentanyl injection were included in Group 1, whereas patients who received propofol at 3 min and 6 min after fentanyl injection, respectively, were grouped as Group 2 and Group 3. The total propofol required, the hemodynamic variations and the entropy values were recorded. SSPS version 25.09 (IBM) was used for statistical analysis. Results: In this study, it was observed that there was a significant reduction in propofol requirement in Group 2 and Group 3 compared with Group 1. The incidence of hypotension was seen in about 42.9% of Group 1 when compared to Group 2 and 3, which was 28.6% and 17.8%, respectively. Furthermore, the entropy values in Group 3 were initially higher and later were comparable in all the groups. Conclusion: Our study concluded that as the duration between the administration of propofol and fentanyl increases, the hemodynamic stability also increases and there is no variation in the depth of anesthesia attained in the distinct study population.

Analysis and Preliminary Results of a Feedback-Feedforward Controller for Depth of Anesthesia

In a computer-based anaesthesia control system, the depth of hypnosis must be correctly maintained. The regulated variable is the Bispectral Index scale (BIS) controlled via the Propofol drug rate. The anesthesiologist administers Propofol to prevent unwanted fluctuations in the controlled variable during surgical stimulation, which acts as an unmeasurable disturbance on the BIS signal. In this paper, a feedback controller is paired with a feedforward control action. Based on existing clinical protocols, a digitalized disturbance signal that mimics the actual surgical stimulus is employed in the feedforward controller design as a measurable disturbance. To account for the time delay in the BIS measurements, a time delay estimation algorithm is developed and used to estimate the patient time delay. The digitalized disturbance signal is then shifted based on the estimated time delay to ensure a pre-emptive action of the feedforward controller. Two different designs of the feedforward controller are developed. Closed loop simulations considering a nominal patient with and without the feedforward control action are presented and compared. The results show that the surgical stimulus is better tackled using a feedforward control action, even if the actual surgical stimulus is not entirely known.

Intraoperative control of the depth of anesthesia and analgesia using a non-invasive monitor Conox in laparoscopic cholecystectomy

Intraoperative control of the depth of anesthesia and analgesia using a non-invasive monitor Conox in laparoscopic cholecystectomy

Role of artificial intelligence in perioperative monitoring in anaesthesia.

Artificial intelligence (AI) is making giant strides in the medical domain, and the field of anaesthesia is not untouched. Enhancement in technology, especially AI, in many fields, including medicine, has proven to be far superior, safer and less erratic than human decision-making. The intersection of anaesthesia and AI holds the potential for augmenting constructive advances in anaesthesia care. AI can improve anaesthesiologists' efficiency, reduce costs and improve patient outcomes. Anaesthesiologists are well placed to harness the advantages of AI in various areas like perioperative monitoring, anaesthesia care, drug delivery, post-anaesthesia care unit, pain management and intensive care unit. Perioperative monitoring of the depth of anaesthesia, clinical decision support systems and closed-loop anaesthesia delivery aid in efficient and safer anaesthesia delivery. The effect of various AI interventions in clinical practice will need further research and validation, as well as the ethical implications of privacy and data handling. This paper aims to provide an overview of AI in perioperative monitoring in anaesthesia.

The Anesthetic Effect of Oral Administration of α-Chloroaldose and Dexmedetomidine on Silver Fox

In the past, anesthesia was delivered to foxes mostly through intramuscular or subcutaneous injection, which caused substantial stress to the animals, making it necessary to restrain them physically before the procedure. Moreover, research on anesthesia technology for domestic animals has been insufficient. Therefore, in this study, the α-chloroaldose and dexmedetomidine combination was used via oral administration to anesthetize foxes. Ten healthy silver foxes were administered the combination of oral anesthesia, and routine physiological indicators, anesthesia time and effects, and biological reflexes were continuously monitored. The temperature of anesthetized foxes after the administration of oral anesthesia continued to decrease, and by the end of the monitoring, it decreased by 1.3°C.The average SpO2 was 95.3 ± 2.2% during the whole anesthesia period. Changes in the heart rate were significant, initially showing a decreasing trend and then an increasing trend. The anesthesia period showed characteristics of smooth induction, proper maintenance, and rapid recovery. The sedative, analgesic, and muscle relaxant effects were more balanced and provided a good anesthesia effect time of 30 min: corneal, eyelid, and anal biological reflexes persisted and were inhibited at 20~50 min after oral medication, which shows a suitable depth of anesthesia.

XAI-VSDoA: An Explainable AI-Based Scheme Using Vital Signs to Assess Depth of Anesthesia

XAI-VSDoA: An Explainable AI-Based Scheme Using Vital Signs to Assess Depth of Anesthesia

Chronic full-band recordings with graphene microtransistors as neural interfaces for discrimination of brain states.

Brain states such as sleep, anesthesia, wakefulness, or coma are characterized by specific patterns of cortical activity dynamics, from local circuits to full-brain emergent properties. We previously demonstrated that full-spectrum signals, including the infraslow component (DC, direct current-coupled), can be recorded acutely in multiple sites using flexible arrays of graphene solution-gated field-effect transistors (gSGFETs). Here, we performed chronic implantation of 16-channel gSGFET arrays over the rat cerebral cortex and recorded full-band neuronal activity with two objectives: (1) to test the long-term stability of implanted devices; and (2) to investigate full-band activity during the transition across different levels of anesthesia. First, we demonstrate it is possible to record full-band signals with stability, fidelity, and spatiotemporal resolution for up to 5.5 months using chronic epicortical gSGFET implants. Second, brain states generated by progressive variation of levels of anesthesia could be identified as traditionally using the high-pass filtered (AC, alternating current-coupled) spectrogram: from synchronous slow oscillations in deep anesthesia through to asynchronous activity in the awake state. However, the DC signal introduced a highly significant improvement for brain-state discrimination: the DC band provided an almost linear information prediction of the depth of anesthesia, with about 85% precision, using a trained algorithm. This prediction rose to about 95% precision when the full-band (AC + DC) spectrogram was taken into account. We conclude that recording infraslow activity using gSGFET interfaces is superior for the identification of brain states, and further supports the preclinical and clinical use of graphene neural interfaces for long-term recordings of cortical activity.

Physiological effects of alfaxalone anesthesia on rhesus monkeys during intravenous glucose tolerance testing.

Laboratory animal research with nonhuman primates (NHPs) requires anesthesia for most procedures to ensure safety and consistency in sample collection. However, anesthesia drugs can have adverse effects on the physiological measures of interest. Alfaxalone, most notably used in dogs and cats, offers rapid onset, short duration of action, and has a high safety margin. Here, we compared our current anesthesia protocol using Telazol, to three different doses of alfaxalone during a one-hour intravenous glucose tolerance test, the standard evaluation of glucose metabolism in NHPs. Results indicate there are no differences in the rate of glucose metabolism, anesthesia depth measurements, or total duration of sedation, but induction, number of supplemental doses required, and recovery time to eating were affected by the different doses of alfaxalone. Cardiovascular measures showed variability between the four protocols in respiratory rate and systolic blood pressure rates only. These results indicate that alfaxalone can produce a reliable state of anesthesia, similar to our current protocol, and confers minimal cardiovascular or metabolic disturbance, as well as enhanced recovery characteristics. As such, alfaxalone is a promising anesthetic for use in laboratory animals and further investigation is warranted.

Total intravenous anesthesia with propofol-ketamine-xylazine with or without remifentanil in thoroughbred horses undergoing castration.

We evaluated the clinical efficacy of total intravenous anesthesia (TIVA) with propofol-ketamine-xylazine (PKX) with or without remifentanil for castration in horses. Twenty-four Thoroughbred horses were premedicated with intravenous (IV) xylazine (1.0 mg/kg) and midazolam (0.02 mg/kg) and anesthetized with IV ketamine (1.5 mg/kg) and propofol (1.0 mg/kg). Surgical anesthesia was maintained with constant infusion of propofol (3.0 mg/kg/hr)-ketamine (3.0 mg/kg/hr)-xylazine (1.0 mg/kg/hr) (group PKX: n=8), PKX combined with remifentanil (3.0 µg/kg/hr) (group PKXR3: n=8), or PKX combined with remifentanil (6.0 µg/kg/hr) (group PKXR6: n=8). During anesthesia, none of the horses showed any limb movements, but five, two, and two horses in the PKX, PKXR3, and PKXR6 groups, respectively, showed cremaster muscle contractions. One horse in the PKX group required doubling the PKX infusion rate to continue surgery. Adverse effects of remifentanil (trembling of the nose tip or tongue) were observed in one and three horses in the PKXR3 and PKXR6 groups, respectively. Heart rate and arterial blood pressure were well maintained in all groups. Ventilation was assisted in four, five, and six horses in the PKX, PKXR3, and PKXR6 groups, respectively. Recovery scores in the PKX group were fair in one horse, good in three horses, and excellent in four horses, whereas recovery in all horses in the PKXR3 and PKXR6 groups was judged to be excellent. TIVA with PKX combined with remifentanil 3.0 µg/kg/hr could provide more sufficient anesthetic depth than PKX with fewer clinically significant adverse effects than that with remifentanil 6.0 µg/kg/hr.

Critical key points for anesthesia in experimental research involving sheep (Ovis aries)

Anesthesia and analgesia have a major impact on ensuring animal welfare and safety, resulting in reduced stress response and effective pain control, ensuring the comfort of the animal, promoting faster recovery, and reducing the risk of complications associated with various research procedures. Each stage of anesthesia in sheep is vital for maintaining the animal's welfare, ensuring procedural success, minimizing stress, risks, and complications, and optimizing the quality of research data. Proper attention to detail and adherence to best practices at each stage contribute to the overall success of anesthesia management in sheep. Anesthesia protocols should suit individual requirements for each sheep, in light of factors such as health status, procedure duration, and desired anesthesia depth. Meticulous monitoring, adherence to best practices, and prompt intervention are essential for minimizing the risks of complications during sheep anesthesia and ensuring the safety and welfare of the animals undergoing anesthesia for research purposes. This article presents the main key points that can improve anesthetic management for sheep involved in experimental research to minimize stress response and complications, enhancing animal safety, welfare, and comfort during and after procedures. Multimodal anesthesia approaches ensure effective pain relief, tailored to the specific needs of individual animals or procedures, optimizing outcomes and minimizing risks. Anesthesia management contributes to improved research data collection under conditions that enhance the validity and reliability of results. Sheep's impressive capacity to maintain homeostasis even during extended periods of anesthesia highlights the critical importance of upholding data quality in alignment with the universally accepted principles of Replacement, Reduction, and Refinement for ethical animal research. By adhering to these principles, researchers can minimize the number of animals used, reduce any potential discomfort or distress experienced by the animals, and refine procedures to optimize animal welfare while still achieving scientific objectives.

Exploring the Role of Bispectral Index in Interrupting CPR for ROSC Diagnosis: A Call for Further Research

The current approach in cardiopulmonary resuscitation (CPR) involves interrupting the chest compressions to assess the pulse and diagnose Return of Spontaneous Circulation (ROSC). This critical step is essential for determining the effectiveness of resuscitation efforts. However, the interruption of CPR poses a challenge, prompting researchers to explore alternative methods for diagnosing ROSC without compromising the ongoing resuscitation process.
 One potential solution proposed in the literature is the use of the Bispectral Index (BIS). BIS is a numerical value derived from processed electroencephalogram data, providing a measure of the depth of anesthesia or sedation. Some studies have reported an increase in BIS values following successful ROSC during CPR. This observation suggests that monitoring BIS levels could offer real-time information about cerebral perfusion and neurological status, eliminating the need for pulse checks that require CPR interruption.
 Despite these promising indications, it is crucial to acknowledge the limited existing literature on the subject. The evidence supporting the use of BIS in diagnosing ROSC during CPR is not yet robust, and further research is warranted. Researchers are encouraged to delve into this unexplored area, conducting comprehensive studies to assess the reliability and effectiveness of BIS as a tool for continuous monitoring during resuscitation efforts.
 In conclusion, while the concept of using BIS to diagnose ROSC during CPR holds potential, it remains an area that requires substantial research attention. The limited existing literature underscores the need for more extensive investigations to determine the feasibility and reliability of integrating BIS into the CPR protocol. As technology advances, exploring innovative approaches for continuous assessment during resuscitation becomes imperative for improving outcomes in cardiac arrest scenarios

Electroencephalographic density spectral array monitoring during propofol/sevoflurane coadministration in children, an exploratory observational study

IntroductionPropofol and sevoflurane have a long history in pediatric anesthesia. Combining both drugs at low dose levels offers new opportunities. However, monitoring the hypnotic effects of this drug combination in children is challenging, because the currently available processed EEG-based systems are insufficiently validated in young children and the co-administration of anesthetics. This study investigated electroencephalographic density spectral array monitoring during propofol/sevoflurane coadministration with fixed sevoflurane- and variable propofol dosages. Patients and methodsWe analyzed the density spectral array pattern recorded during propofol/sevoflurane anesthesia in pediatric patients from birth to 11 years of age. Data from 78 patients were suitable for analysis. The primary outcome parameter of this study was the correlation between variable propofol dosages and the expression of the four electroencephalogram frequency bands β, α, θ, and δ. The main secondary outcome parameters were the intra-operative total EEG power and the prevalence of burst suppression. ResultsIn patients above the age of 1 year, a dose-dependent correlation between the propofol dosage and the relative percentage of β (−12.2%, p < 0.001) and δ (5.1%, p < 0.001) was found. There was an age-dependent trend toward increasing mean EEG power, with the most significant increase in the first year of life. In 14.1% of our patients, at least one episode of burst suppression occurred. ConclusionDSA-guided augmentation of propofol anesthesia with sevoflurane provides sufficient depth of anesthesia at doses usually considered sub-anesthetic in children, leading to less anesthetic drug exposure for the individual child.

Hypnosis measured with monitors of anesthetic depth - EEG changes during the test for Harvard Group Scale of Hypnotic Susceptibility.

Hypnotic trance can be defined as a non-ordinary state of consciousness that is accompanied by a number of neurophysiological changes, including brain electrophysiology. In addition to subjective measures, corresponding objective parameters are needed in experimental and clinical hypnosis research but are complex, impractical, or unspecific. A similar challenge exists for the measurement and monitoring of drug-induced hypnosis, namely general anesthesia. The observation of changes in EEG induced by narcotics has led to the development of monitors for the depth of anesthesia based on EEG parameters. We investigated whether two such monitors react to the induction and maintenance of hypnosis during a highly standardized procedure. A total of 56 volunteers were monitored for the bispectral index (BIS) and cerebral state index (CSI) (range 0-100, >95 considered "awake") during the Harvard Group Scale of Hypnotic Susceptibility test. For this test, trance is induced by a taped text and followed by 12 tasks performed under hypnosis. In contrast to random forms of hypnosis, this represents a standardized, worldwide-established condition. According to the resulting score, participants were classified into suggestibility groups in order to evaluate whether the electrophysiological measurements of BIS and CIS indices differ between high and low suggestible persons. Furthermore, participants were asked to rate their hypnotic depth (HD, 1-10) at every task of the test. Scores dropped significantly from a mean of 97.7 to 86.4 for BIS and from 94.6 to 77.7 for CSI with the induction of hypnosis to stay throughout hypnosis at levels of approximately 88.6 or 82.9, respectively. Results did not differ between high- and low-suggestible participants. The means of the subjective score of hypnotic depth and of the electrophysiological measurements showed a similar course. However, no correlation was found between BIS or CSI values and scores of hypnotic depths. Monitors for depth of anesthesia respond to changes in consciousness, including trance states of hypnosis. However, specificity is unclear. Practically, in hypnosis research with the exclusion of drug effects or sleep, these monitors might be helpful to test and compare the efficacy of induction texts and to detect disturbances of trance state.

Comparison of post-auricular and frontal bispectral index values obtained during renal surgeries

BackgroundThe bispectral index (BIS) monitor is one of the EEG-derived monitoring techniques and well-established devices used to measure the depth of anesthesia. This study aimed to assess the agreement of BIS values based on the positions of either post-auricular or frontal sensors in individual patients undergoing renal surgeries while lateral positions at various stages of anesthesia.Patients and methods12 patients older than 18 years, ASA I-III patients scheduled for elective renal operations, two BIS were placed on each patient, one on each side of the post-auricular region and one across the forehead, and each sensor was connected to a different BIS monitor. We gathered three pieces of data at each of the six-time points: BIS score, signal quality index (SQI) score calculating the signal’s strength and electromyography (EMG) score: before the onset of anesthesia (awake) when the eyelash reflex is lost (LOC), after intubation (intubation), following the initial surgical incision, each 30 min throughout the procedure (maintenance), and at the moment the patient’s eyes open naturally after waking up from anesthesia (emergence).ResultsThe overall BIS value at the frontal position was significantly higher than the post-auricular position (52.5 ± 22.2 and 52.1 ± 22.1, respectively, P = 0.010). On the other hand, the BIS value was comparable between the frontal and post-auricular positions at LOC, intubation, 60, 120, and 80 min and at emergence. A strong link between the two sensor positions, as indicated by the correlation coefficient (r = 0.607, P < 0.001), and the Bland-Altman analysis revealed a small mean difference (-1.8) and a low (9.0/- 12.5) limit of agreement, with just 4.3% of the readings falling outside of it during the anesthetic maintenance period.ConclusionAcceptable variation in BIS data was observed when obtained from the two different sensor positions for clinical usage. The post-auricular BIS sensor system may be a suitable substitute for an impractical frontal setup.Protocol RegistrationThe study was registered in clinicaltrials.gov on 11/07/2022 (trial registration number: NCT05451823).

Effect of remimazolam on electroencephalogram burst suppression in elderly patients undergoing cardiac surgery: Protocol for a randomized controlled noninferiority trial

BackgroundPostoperative delirium (POD) is a common complication following cardiac surgery and increases postoperative morbidity and mortality. Intraoperative electroencephalogram (EEG) burst suppression suggests excessively deep anesthesia and predicts POD. Use of remimazolam provides a stable hemodynamic status and an appropriate depth of anesthesia. We aim to assess remimazolam administered for anesthesia and sedation in elderly patients having cardiac surgery. MethodsThis is a randomized controlled clinical trial with noninferiority design. A total of 260 elderly patients aged equal to or greater than 60 years undergoing cardiac surgery will be randomly allocated to receive remimazolam or propofol (1:1) for general anesthesia and postoperative sedation until extubation. The primary outcome is the cumulative time with EEG burst suppression which is obtained from the SedLine system. The noninferiority margin is 2.0 min. The secondary outcomes include the POD occurrence within the first 5 days postoperatively and the duration of perioperative hypotension. DiscussionThis noninferiority trial is the first to evaluate the effect of perioperative remimazolam administration on EEG burst suppression, POD occurrence, and duration of hypotension in elderly patients who undergo cardiac surgery. Trial registrationChinese Clinical Trial Registry (ChiCTR2200056353).

Commonly used anesthetics modify alcohol and (-)-trans-delta9-tetrahydrocannabinol in vivo effects on rat cerebral arterioles

BackgroundEthyl alcohol and cannabis are widely used recreational substances with distinct effects on the brain. These drugs increase accidental injuries requiring treatment under anesthesia. Moreover, alcohol and cannabis are often used in anesthetized rodents for biomedical research. Here, we compared the influence of commonly used forms of anesthesia, injectable ketamine/xylazine (KX) versus inhalant isoflurane, on alcohol- and (-)-trans-delta9-tetrahydrocannabinol (THC) effects on cerebral arteriole diameter evaluated in vivo.MethodsStudies were performed on male and female Sprague–Dawley rats subjected to intracarotid catheter placement for drug infusion, and cranial window surgery for monitoring pial arteriole diameter. Depth of anesthesia was monitored every 10–15 min by toe-pinch. Under KX, the number of toe-pinch responders was maximal after the first dose of anesthesia and diminished over time in both males and females. In contrast, the number of toe-pinch responders under isoflurane slowly raised over time, leading to increase in isoflurane percentage until deep anesthesia was re-established. Rectal temperature under KX remained stable in males while dropping in females. As expected for gaseous anesthesia, both males and females exhibited rectal temperature drops under isoflurane.ResultsInfusion of 50 mM alcohol (ethanol, EtOH) into the cerebral circulation rendered robust constriction in males under KX anesthesia, this alcohol action being significantly smaller, but still present under isoflurane anesthesia. In females, EtOH did not cause measurable changes in pial arteriole diameter regardless of the anesthetic. These findings indicate a strong sex bias with regards to EtOH induced vasoconstriction.Infusion of 42 nM THC in males and females under isoflurane tended to constrict cerebral arterioles in both males and females when compared to isovolumic infusion of THC vehicle (dimethyl sulfoxide in saline). Moreover, THC-driven changes in arteriole diameter significantly differed in magnitude depending on the anesthetic used.Simultaneous administration of 50 mM alcohol and 42 nM THC to males constricted cerebral arterioles regardless of the anesthetic used. In females, constriction by the combined drugs was also observed, with limited influence by anesthetic presence.ConclusionsWe demonstrate that two commonly used anesthetic formulations differentially influence the level of vasoconstriction caused by alcohol and THC actions in cerebral arterioles.

CLINICAL EFFECTIVENESS OF BISPECTRAL INDEX TO REDUCE THE RISK OF AWARENESS FOR ELECTIVE SURGICAL PATIENTS UNDER GENERAL ANESTHESIA: AN OBSERVATIONAL STUDY

Objective: The objective of this study was to reduce the risk of intraoperative awareness (IA) for patients undergoing elective surgeries under general anesthesia. Methods: A prospective, observational study was conducted on 98 adult patients undergoing elective surgeries under general anesthesia to assess IA using bispectral index (BIS) monitoring. The study was carried out from October 2019 to February 2021 after obtaining consent from the institutional ethics committee. Results: In our study, using BIS monitoring percentage of patients remembering anything in between the operation is only 1.03% and percentage of patients not dreaming during the operation is about 98.97%. BIS monitoring is safe and has predictable values in the depth of anesthesia for reducing the IA in general anesthesia. Conclusion: We conclude that BIS monitoring would be a helpful tool in reducing the risk of awareness for patients undergoing surgeries under general anesthesia.