Do all sedatives promote biological sleep electroencephalogram patterns? A machine learning framework to identify biological sleep promoting sedatives using electroencephalogram.

BACKGROUND: Sedatives are commonly used to promote sleep in intensive care unit patients. However, it is not clear whether sedation-induced states are similar to the biological sleep. We explored if sedative-induced states resemble biological sleep using multichannel electroencephalogram (EEG) recordings. METHODS: Multichannel EEG datasets from two different sources were used in this study: (1) sedation dataset consisting of 102 healthy volunteers receiving propofol (N = 36), sevoflurane (N = 36), or dexmedetomidine (N = 30), and (2) publicly available sleep EEG dataset (N = 994). Forty-four quantitative time, frequency and entropy features were extracted from EEG recordings and were used to train the machine learning algorithms on sleep dataset to predict sleep stages in the sedation dataset. The predicted sleep states were then compared with the Modified Observer's Assessment of Alertness/ Sedation (MOAA/S) scores. RESULTS: The performance of the model was poor (AUC = 0.55-0.58) in differentiating sleep stages during propofol and sevoflurane sedation. In the case of dexmedetomidine, the AUC of the model increased in a sedation-dependent manner with NREM stages 2 and 3 highly correlating with deep sedation state reaching an AUC of 0.80. CONCLUSIONS: We addressed an important clinical question to identify biological sleep promoting sedatives using EEG signals. We demonstrate that propofol and sevoflurane do not promote EEG patterns resembling natural sleep while dexmedetomidine promotes states resembling NREM stages 2 and 3 sleep, based on current sleep staging standards.

Comparing different postoperative sedation strategies for patients in the intensive care unit after cardiac surgery: A systematic review of randomized controlled trials and network meta-analysis.

BACKGROUND: Various postoperative sedation protocols with different anaesthetics lead to profound effects on the outcomes for post-cardiac surgery patients. However, a comprehensive analysis of optimal postoperative sedation strategies for patients in the intensive care unit (ICU) after cardiac surgery is lacking. METHODS: We systematically searched for randomized controlled trials (RCTs) in databases including PubMed and Embase. The primary outcome measured the duration of mechanical ventilation (MV) in the ICU, and the secondary outcome encompassed the length of stay (LOS) in the ICU and hospital and the monitoring adverse events. RESULTS: The literature included 18 RCTs (1652 patients) with 13 sedation regimens. Dexmedetomidine plus ketamine and sevoflurane were associated with a significantly reduced duration of MV when compared with propofol. Our results also suggested that dexmedetomidine plus ketamine may associated with a shorter LOS in ICU, and sevoflurane associated with a shorter LOS in the hospital, respectively. CONCLUSIONS: The combination of dexmedetomidine and ketamine seems to be a better option for adult patients needing sedation after cardiac surgery, and the incidence of side effects is lower with dexmedetomidine. These findings have potential implications for medication management in the perioperative pharmacotherapy of cardiac surgery patients.

Study on the preventive effect of dexmedetomidine on anesthetic associated sleep disturbance in young to middle-aged female patients undergoing hysteroscopy: a study protocol for a crossover randomized controlled trial.

BACKGROUND: Postoperative sleep disturbance has a potentially detrimental effect on postoperative recovery. Perioperative patients are affected by several factors. General anesthesia induces a non-physiological state that does not resemble natural sleep. Exposure to propofol/sevoflurane can lead to desynchronization of the circadian rhythm, which may result in postoperative sleep disturbance characterized by mid-cycle advancement of sleep and daytime sleepiness. Dexmedetomidine is a highly selective α2-adrenoceptor agonist with a unique sedative effect that facilitates the transition from sleep to wakefulness. Basic research has shown that dexmedetomidine induces deep sedation, similar to physical sleep, and helps maintain forebrain connectivity, which is likely to reduce delirium after surgery. The aim of this study is to evaluate the influence of exposure to the mono-anesthetic propofol on the development of postoperative sleep disturbance in young and middle-aged female patients undergoing hysteroscopy and whether prophylactic administration of dexmedetomidine influences reducing postoperative sleep disturbance. METHODS: This prospective randomized controlled trial (RCT) will include 150 patients undergoing hysteroscopy at the First Affiliated Hospital of Xiamen University. Participants will be randomly assigned to three groups in a 1:1:1 ratio. The dexmedetomidine group will have two subgroups and will receive a nasal spray of 0.2 µg/kg or 0.5 µg/kg 25 min before surgery, while the control group will receive a saline nasal spray. Three groups will undergo hysteroscopy with propofol-based TIVA according to the same scheme. Sleep quality will be measured using a wearable device and double-blind sleep assessments will be performed before surgery and 1, 3, and 7 days after surgery. SPSS 2.0 is used for statistical analysis. A χ2 test is used to compare groups, and t-test is used to determine statistical the significance of continuous variables. DISCUSSION: The purpose of this study is to investigate the incidence of propofol-associated sleep disorders and to test a combination of dexmedetomidine anesthesia regimen for the prevention of postoperative sleep disorders. This study will help to improve patients' postoperative satisfaction and provide a new strategy for comfortable perioperative medical treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT06281561. Registered on February 24, 2024.

Survival benefits of propofol-based versus inhalational anesthesia in non-metastatic breast cancer patients: a comprehensive meta-analysis.

Whether the anesthesia technique, inhalational general anesthesia (IGA) or propofol-based anesthesia (PBA), influences the long-term survival of non-metastatic breast cancer (eBC) remain unclear and controversial. We carried out a literature search on 16thJuly, 2022 for studies comparing IGA and PBA in eBC undergoing standard surgery, according to PRISMA 2020. The major endpoint in our study was overall survival (OS). Seventeen studies including four randomized clinical trials and thirteen retrospective cohort studies were included in the meta-analysis. Ten studies provided data for crude OS in unweighted eBC patients (imbalance in baseline characteristics). The summarized estimate HRs of the PBA group versus the IGA group (ten studies, N = 127,774, IGA group: 92,592, PBA group: 35,182.) was 0.83 (95%CI: 0.78-0.89). Compared with IGA, PBA was associated with both better 1-year OS (two studies, N = 104,083, IGA group: 84,074, PBA group: 20,009. Pooled HR = 0.80, 0.73-0.89) and 5-year OS (six studies, N = 121,580, IGA group: 89,472, PBA group: 32,108. HR = 0.80, 0.74-0.87). Ten studies applied PSM method to balance the baseline characteristics. In these weighted patients, PBA still showed a better OS (ten studies, N = 105,459, IGA group: 79,095, PBA group: 26,364. HR = 0.93, 0.87-1.00), a better 1-year OS (two studies, N = 83,007, IGA group: 67,609, PBA group: 15,398. HR = 0.88, 0.78-0.98) and a trend towards a better 5-year OS (nine studies, N = 121,580, IGA group: 76,797, PBA group: 24,066. HR = 0.95, 0.88-1.03). Loco-regional recurrence-free survival (LRRFS) was also better in PBA group (HR = 0.73, 0.61-0.86). The present study is the first comprehensive meta-analysis to demonstrate that propofol-based anesthesia could significantly improve OS and LRRFS in non-metastatic breast cancer patients, compared with inhalational anesthesia.

Safety of propofol-assisted deep extubation in the dental treatment of children-a retrospective, observational study.

PURPOSE: Awake extubation and deep extubation are commonly used anesthesia techniques. In this study, the safety of propofol-assisted deep extubation in the dental treatment of children was assessed. MATERIALS AND METHODS: Children with severe caries who received dental treatment under general anesthesia and deep extubation between January 2017 and June 2023 were included in this study. Data were collected on the following variables: details and time of anesthesia, perioperative vital signs, and incidence of postoperative complications. The incidence of laryngeal spasm (LS) was considered to be the primary observation indicator. RESULTS: The perioperative data obtained from 195 children undergoing dental treatment was reviewed. The median age was 4.2 years (range: 2.3 to 9.6 years), and the average duration of anesthesia was 2.56 h (range 1 to 4.5 h). During intubation with a videoscope, purulent mucus was found in the pharyngeal cavity of seven children (3.6%); LS occurred in five of them (2.6%), and one child developed a fever (T = 37.8 °C) after discharge. Five children (2.6%) experienced emergence agitation (EA) in the recovery room. Also, 13 children (6.7%) experienced epistaxis; 10 had a mild experience and three had a moderate experience. No cases of airway obstruction (AO) and hypoxemia were recorded. The time to open eyes (TOE) was 16.3 ± 7.2 min. The incidence rate of complications was 23/195 (11.8%). Emergency tracheal reintubation was not required. Patients with mild upper respiratory tract infections showed a significantly higher incidence of complications (P < 0.001). CONCLUSIONS: Propofol-assisted deep extubation is a suitable technique that can be used for pediatric patients who exhibited non-cooperation in the outpatient setting. Epistaxis represents the most frequently encountered complication. Preoperative upper respiratory tract infection significantly increases the risk of complications. The occurrence of EA was notably lower than reported in other studies.

Comparison of remimazolam tosilate and propofol during induction and maintenance of general anesthesia in patients undergoing laparoscopic cholecystectomy: a prospective, single center, randomized controlled trial.

BACKGROUND: Remimazolam tosilate (RT) is a new, ultrashort-acting benzodiazepine. Here, we investigated the efficacy and safety of RT for general anesthesia in patients undergoing Laparoscopic Cholecystectomy (LC). METHODS: In this study, 122 patients undergoing laparoscopic cholecystectomy were randomly allocated to receive either remimazolam tosilate (Group RT) or propofol group (Group P). RT was administered as a slow bolus of 0.3 mg kg- 1 for induction, followed by 1.0-2.0 mg kg- 1 h- 1 for maintenance of general anesthesia. Propofol was started at 2 mg kg- 1 and followed by 4-10 mg kg- 1 h- 1 until the end of surgery. The primary outcome was the time to bispectral index (BIS) ≤ 60. The secondary outcome included the time to loss of consciousness (LoC), and the time to extubation. Adverse events were also assessed. RESULTS: A total of 112 patients were recruited for study participation. Among them, the time to BIS ≤ 60 in Group RT was longer than that in Group P (Group RT: 89.3 ± 10.7 s; Group P: 85.9 ± 9.7 s, P > 0.05). While the time to LoC comparing remimazolam and propofol showed no statistical significance (Group RT: 74.4 ± 10.3 s; Group P: 74.7 ± 9.3 s, P > 0.05). The time to extubation in Group RT was significantly longer than that in Group P (Group RT: 16.0 ± 2.6 min; Group P: 8.8 ± 4.3 min, P < 0.001). Remimazolam tosilate had more stable hemodynamics and a lower incidence of hypotension during general anesthesia. CONCLUSIONS: Remimazolam tosilate can be safely and effectively used for general anesthesia in patients undergoing Laparoscopic Cholecystectomy. It maintains stable hemodynamics during induction and maintenance of general anesthesia compared with propofol. Further studies are needed to validate the findings. TRIAL REGISTRATION: Chictr.org.cn ChiCTR2300071256 (date of registration: 09/05/2023).

Comparison of the effects of axillary brachial plexus block, inhalation anesthesia, and total intravenous anesthesia on tourniquet-induced ischemia-reperfusion injury in upper extremity surgery.

BACKGROUND: Post-ischemia reperfusion can lead to oxidative stress and an increase in oxidative markers. Employing preventive strategies and antioxidant agents may help mitigate ischemia-reperfusion injury (IRI). The use of a tourniquet in extremity surgery has been associated with IRI. This study aims to investigate the impact of three different approaches- brachial plexus block, total intravenous anesthesia (TIVA), and inhalation anesthesia-on IRI during upper extremity surgery using a tourniquet. METHODS: Patients aged 18 to 45 with American Society of Anesthesiologists (ASA) I-II scores were randomly assigned to one of three groups: Group A received an axillary block with bupivacaine; Group I underwent inhalation anesthesia with sevoflurane; and Group T received TIVA with propofol and remifentanil infusion. Blood samples were collected to measure glucose, lactate, total anti-oxidant status (TAS), total oxidant status (TOS), and ischemia-modified albumin (IMA) levels at various time points: before anesthesia (t1), 1 minute before tourniquet release (t2), 20 minutes after tourniquet release (t3), and 4 hours after tourniquet release (t4). RESULTS: In Group I, lactate levels at t3, and glucose levels at t2 and t3, were higher compared to the other groups. Group A exhibited lower IMA levels at t2, t3, and t4 than the other groups. Additionally, Group I had lower IMA levels at t2, t3, and t4 compared to Group T. TAS levels were higher in Group I at t2, t3, and t4 compared to the other groups. TOS levels at t2 and t3 were lower in Group A than in Group I. CONCLUSION: Axillary anesthesia results in a sympathetic block, promoting better perfusion of the upper extremity. This study demonstrated lower levels of oxidative stress markers with axillary plexus block. Therefore, these results suggest that the axillary block has the potential to mitigate IRI.

Etomidate Combined with Propofol versus Remimazolam for Sedation in Elderly Patients During Gastrointestinal Endoscopy: A Randomized Prospective Clinical Trial.

Purpose: Remimazolam is a novel short-acting benzodiazepine used for sedation and general anesthesia. This study aimed to evaluate the efficacy and safety of remimazolam besylate in elderly patients who underwent diagnostic gastrointestinal endoscopy. Patients and Methods: A total of 120 patients aged 60-75 years were randomly allocated to one of two groups. Remifentanil 0.3µg/kg was used for analgesia. Patients were administered remimazolam besylate 7 mg (R group) or etomidate 0.1 mg/kg combined with 1% propofol 0.5 mg/kg (EP group) for induction, supplemental repeated doses were given as needed. Some time metrics, vital signs, adverse events were evaluated. Patients' Mini-cog score and recovery questionnaires were compared. Results: Compared to the EP group, the induction time was slightly longer in the R group (1.50 VS 1.15 minutes) (P<0.05), the time spent in the post-anesthesia care unit (PACU) was shorter (15.17 VS 17.40 minutes) (P<0.05). Compare with EP group, SBP was lower in R group at T15 and T25 time point, but heart rate was higher in T2, T3, T5 (P< 0.05). The Mini-Cog score was higher after the procedure (2.83 VS 2.58) (P<0.05). The incidence of respiratory adverse events was higher in the EP group than R group (18.3% VS 5.0%, P < 0.05). The most common adverse event in R group was hiccups. The sedation satisfaction rate and degree of amnesia were higher in the R group (66.7% VS 11.7%) (P < 0.05), and the effect on patient's life within 24 hours was lower (12.0% VS 30.5%) (P < 0.05). Conclusion: The safety and efficacy of remimazolam besylate are not inferior to those of etomidate combined with propofol, rendering it a safe option for sedation during gastrointestinal endoscopy in ASA I-II elderly patients, but care should be taken to monitor the occurrence of hiccups.

Comparisons of different general anesthetic techniques on immune function in patients undergoing flap reconstruction for oral cancer.

BACKGROUND: Anesthetic-induced immunosuppression is of particular interest in tumor surgery. This study aimed to investigate the influence of the 4 most common general anesthetic techniques on immune function in patients undergoing flap reconstruction for oral cancer. METHODS: 116 patients were randomly divided into 4 groups. Patients in group S were given sevoflurane-based anesthesia. Group P was administered propofol-based anesthesia. The SD group received sevoflurane combined with dexmedetomidine anesthesia. The propofol combined with dexmedetomidine anesthesia (PD) group received PD. Blood samples were obtained at 5 time points: baseline (T0), 1 hour after the start of the operation (T1), end of the operation (T2), 24 hours (T3), and 48 hours (T4) after the operation. Lymphocyte subsets (including CD3+, CD4+, CD8+, and B lymphocytes) and dendritic cells were analyzed by flow cytometry. Blood glucose, norepinephrine, and cortisol levels were measured using ELISA and a blood gas analyzer respectively. RESULTS: In total, 107 patients were included in the final analysis. Immunological indicators, except CD8+ counts, were all decreased in groups S, P, and SD at T1-4 compared with the baseline value, and the counts of CD3+, CD4+, and dendritic cells, as well as CD4+/CD8+ ratios, were significantly higher in the PD group than in the S, P, and SD at T1-3 (P < .05). There were no significant differences between groups P and SD at any observation time point. Intraoperative stress indices, including norepinephrine and cortisol levels, were significantly lower in the PD group than in the other 3 groups at T1-2 (P < .05). CONCLUSION: These findings suggest that PD as a probably optimal choice can alleviate immunosuppression in patients undergoing flap reconstruction for oral cancer.

Effects of ciprofol infusion on hemodynamics during induction and maintenance of anesthesia and on postoperative recovery in patients undergoing thoracoscopic lobectomy: Study protocol for a randomized, controlled trial.

INTRODUCTION: Ciprofol, a new candidate drug, is effective and safe for the maintenance of anesthesia in non-cardiothoracic and non-neurological elective surgery. However, few studies have been conducted on general anesthesia using ciprofol in patients undergoing thoracoscopic lobectomy. Therefore, this study aims to observe the effects of ciprofol on hemodynamics and on postoperative recovery in patients undergoing thoracoscopic lobectomy. METHODS AND ANALYSIS: This randomized controlled trial will include 136 patients aged 18-65 years undergoing elective thoracoscopic lobectomy between April 2023 and December 2024. The participants will be randomly assigned to the propofol or ciprofol group. The primary outcome to be assessed is the hemodynamic fluctuation during the induction and maintenance of anesthesia. The secondary outcomes involve quality of anesthesia induction and quality of recovery from anesthesia. The former includes TLOC (time to loss of consciousness), the use of vasoactive agents, the incidence of injection pain, body movement, muscle twitching and coughing during induction of anesthesia. The latter includes TROC (time to recovery of consciousness), post anesthesia care unit (PACU) time, incidence of postoperative nausea and vomiting (PONV), postoperative agitation, intraoperative awareness and quality of recovery (QoR) score. DISCUSSION: A number of clinical trials have confirmed that ciprofol, as a new sedative-hypnotic agent, has advantages of better tolerance, higher sedation satisfaction score, and lower incidence of adverse reactions, especially in reducing the incidence of injection pain. But considering that ciprofol was recently developed, limited data are available regarding its use for general anesthesia. This study aims to investigate the effects of ciprofol on hemodynamics and on postoperative recovery of patients undergoing thoracoscopic lobectomy. The results of this study may provide evidence for the safe application of ciprofol, a new choice of general anesthetic for thoracic surgery. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT05664386).

Comparison of the efficacy and safety of ciprofol and propofol in sedating patients in the operating room and outside the operating room: a meta-analysis and systematic review.

BACKGROUND: As a new type of intravenous anesthetic, ciprofol has the advantages of fast onset of action, fast recovery and high clearance rate. This study aimed to investigate the effectiveness and safety of ciprofol versus traditional propofol for anesthesia and sedation in and out of the operating room. METHODS: We searched the literature in PubMed, Web of Science, Cochrane Library, and Embase databases from January 2021 to December 2023. All clinical studies comparing the sedative effects of propofol and ciprofol, both inside and outside the operating room, were included in our trial. The main outcome measures were induction time and incidence of injection-site pain. Data are merged using risk ratio and standardized mean difference with 95% confidence interval. Subgroup analysis, meta-regression, sensitivity analysis, and publication bias were performed. The study protocol was prospectively registered with PROSPERO (CRD42023447747). RESULTS: A total of 15 randomized, controlled trials involving 2002 patients were included in this study. Compared with propofol, ciprofol has a longer induction time in the operating room but a shorter induction time in non-operating room settings. Ciprofol can effectively reduce the risk of injection-site pain and respiratory depression both inside and outside the operating room. In addition, the risk of drug-related hypotension induced with ciprofol in the operating room is lower, but the awakening time is also longer. Meta-regression analysis showed that neither age nor BMI were potential sources of heterogeneity. Funnel plot, egger and begg tests showed no significant publication bias. Sensitivity analyzes indicate that our results are robust and reliable. CONCLUSION: Ciprofol has absolute advantages in reducing the risk of injection-site pain and respiratory depression, both in and outside operating room. Intraoperative use of ciprofol reduces the risk of drug-related hypotension and may also reduce the risk of intraoperative physical movements. However, ciprofol may have longer induction and awakening time than propofol.

Prospective Pilot Study: Tolerability of Outpatient Penile Plication Under Nursing-Administered Conscious Sedation vs Anesthesiologist-Administered Deep Sedation.

INTRODUCTION: Penile plication is commonly performed for Peyronie's disease under general or spinal anesthesia. Conscious sedation (CS) offers decreased anesthetic risks, cost-effectiveness, and the ability to perform the procedure in outpatient settings with shorter wait times. We sought to compare tolerability of penile plication under deep intravenous sedation (DIS) administered by anesthesiologists and nursing-administered CS (NACS). METHODS: Tolerability for penile plication was prospectively evaluated, excluding revision surgeries and those with hourglass or hinge deformities. DIS included midazolam and ketamine with infusion of propofol and remifentanil. NACS consisted of midazolam and fentanyl. Baseline characteristics, procedural information, and patient- and surgeon-reported pain assessments were collected. Patients were administered a standardized tolerability questionnaire on follow-up. RESULTS: Forty patients were enrolled (23 DIS; 17 NACS) with similar baseline characteristics. Median curvature of the DIS cohort was 55° (interquartile range = 43.75-76.25) and 45° (interquartile range = 45-60) in NACS. There was a 100% success rate with no procedure abortion or conversion to general anesthetic. On follow-up, all patients had functional curvature (<20°), and 100% of patients in the DIS and NACS cohorts reported that they would recommend CS to others. Over 93% of patients in both cohorts would choose CS over general anesthetic in the future, with no differences in perioperative and postoperative pain between groups. CONCLUSIONS: Penile plication with CS, whether administered by an anesthesiologist or nursing, is well tolerated with no differences in pain or complications. This indicates that outpatient penile plication with trained nursing staff administering CS can safely reduce costs, risks, and wait times.

Comparison of Fentanyl, Ketamine, and Lidocaine Combined with Propofol Anesthesia in Patients with Crohn Disease Undergoing Colonoscopy.

BACKGROUND Colonoscopy is the predominant invasive procedure for Crohn disease (CD) patients. Opioids and propofol carry risks of respiratory and cardiovascular complications. This study aimed to evaluate whether substituting fentanyl with ketamine or lidocaine could diminish propofol usage and minimize adverse events. MATERIAL AND METHODS In total, 146 patients with CD scheduled for elective colonoscopy were assigned to anesthesia with fentanyl (n=47), ketamine (n=47), or lidocaine (n=55). Propofol was administered to achieve sufficient anesthesia. Measured outcomes in each group included propofol consumption, hypotension and desaturation incidents, adverse event types, consciousness recovery time, abdominal pain intensity, Aldrete scale, and Post Anaesthetic Discharge Scoring System (PADSS). RESULTS Patients administered fentanyl needed significantly more propofol (P=0.017) than those on ketamine, with lidocaine showing no notable difference (P=0.28). Desaturation was significantly less common in the ketamine and lidocaine groups than fentanyl group (P<0.001). The ketamine group experienced milder reductions in mean arterial (P=0.018) and systolic blood pressure (P<0.001). Recovery metrics (Aldrete and PADSS scores) were lower for fentanyl (P<0.001), although satisfaction and pain levels were consistent across all groups (P=0.797). Dizziness occurred less frequently with lidocaine than fentanyl (17.2%, P=0.018) and ketamine (15.1%, P=0.019), while metallic taste incidents were more prevalent in the lidocaine group (13.5%, P=0.04) than fentanyl group. CONCLUSIONS Using ketamine or lidocaine instead of fentanyl in anesthesia for colonoscopy in patients with CD significantly lowers propofol use, reduces desaturation events, maintains blood pressure more effectively, without increasing hypotension risk, and accelerates recovery, without negatively impacting adverse events or patient satisfaction.

Effect of desflurane anesthesia on flash visual evoked potential monitoring in patients undergoing spine surgery: study protocol for a randomized controlled trial.

BACKGROUND: Flash visual evoked potentials (FVEPs) are a reliable method for protecting visual function during spine surgery in prone position. However, the popularization and application of FVEPs remain limited due to the unclear influence of various anesthetics on FVEPs. Exploring the effects of anesthetic drugs on FVEP and establishing appropriate anesthesia maintenance methods are particularly important for promoting and applying FVEP. According to the conventional concept, inhaled narcotic drugs significantly affect the success of FVEP monitoring, FVEP extraction, and interpretation. Nonetheless, our previous study demonstrated that sevoflurane-propofol balanced anesthesia was a practicable regimen for FVEPs. Desflurane is widely used in general anesthesia for its rapid recovery properties. As the effect of desflurane on FVEP remains unclear, this trial will investigate the effect of different inhaled concentrations of desflurane anesthesia on amplitude of FVEPs during spine surgery, aiming to identify more feasible anesthesia schemes for the clinical application of FVEP. METHODS/ DESIGN: A total of 70 patients undergoing elective spinal surgery will be enrolled in this prospective, randomized controlled, open-label, patient-assessor-blinded, superiority trial and randomly assigned to the low inhaled concentration of desflurane group (LD group) maintained with desflurane-propofolremifentanil-balanced anesthesia or high inhaled concentration of desflurane group (HD group) maintained with desflurane-remifentanil anesthesia maintenance group at a ratio of 1:1. All patients will be monitored for intraoperative FVEPs, and the baseline will be measured half an hour after induction under total intravenous anesthesia (TIVA). After that, patients will receive 0.5 minimum alveolar concentration (MAC) of desflurane combined with propofol and remifentanil for anesthesia maintenance in the LD group, while 0.7-1.0 MAC of desflurane and remifentanil will be maintained in the HD group. The primary outcome is the N75-P100 amplitude 1 h after the induction of anesthesia. We intend to use the dual measure evaluation, dual data entry, and statistical analysis by double trained assessors to ensure the reliability and accuracy of the results. DISCUSSION: This randomized controlled trial aims to explore the superiority effect of low inhaled concentration of desflurane combined with propofolremifentanil-balanced anesthesia versus high inhaled concentration of desflurane combined with remifentanil anesthesia on amplitude of FVEPs. The study is meant to be published in a peer-reviewed journal and might guide the anesthetic regimen for FVEPs. The conclusion is expected to provide high-quality evidence for the effect of desflurane on FVEPs and aim to explore more feasible anesthesia schemes for the clinical application of FVEPs and visual function protection. TRIAL REGISTRATION: This study was registered on clinicaltrials.gov on July 15, 2022. CLINICALTRIALS: gov Identifier: NCT05465330.

The EC50 of propofol with different doses of dexmedetomidine during gastrointestinal endoscopy: A double-blind, placebo-controlled trial.

PURPOSE: The goal of this study was to evaluate the dose-response relationship between dexmedetomidine and propofol in sedating patients and to determine the optimal dosage of dexmedetomidine during gastrointestinal endoscopy. METHODS: One hundred fifty patients were divided into 5 groups, each receiving a loading dose of dexmedetomidine (0.4, 0.6, 0.8, 1.0 µg/kg) or saline, with propofol for sedation. The median effective concentration (EC50) of propofol was calculated using the modified Dixon up-and-down approach. Adverse effects, vital signs, procedure, and recovery times were recorded. RESULTS: The EC50 of propofol in groups NS, D0.4, D0.6, D0.8, and D1.0 were 3.02, 2.44, 1.97, 1.85, and 1.83 µg/mL, respectively. Heart rate in the dexmedetomidine groups decreased more than the NS group (P < .001). The mean arterial pressure (MAP) in the NS group experienced a decline compared to groups D0.8 and D1.0 when the plasma concentration and effect-site concentration reached equilibrium. Additionally, the respiratory rate was found to be lower in groups NS, D0.4, D0.6, and D0.8 (P < .05). Recovery time in groups D0.8 and D1.0 was longer than the NS group (P < .05). Bruggemann comfort scales score was higher in group D1.0 (P < .05). No significant difference was found in the incidences of hypotension and bradycardia, and the dose of ephedrine and atropine. Respiratory depression was significantly reduced in groups D0.8 and D1.0 compared to the NS group. CONCLUSION: A single dose of 0.6 to 0.8 µg/kg of dexmedetomidine should be recommended in combination with propofol for gastrointestinal endoscopy. And the EC50 of propofol is 1.97 to 1.85 µg/mL.

Recommended dosages of analgesic and sedative drugs in intensive care result in a low incidence of potentially toxic blood concentrations.

Background: Standard dosages of analgesic and sedative drugs are given to intensive care patients. The resulting range of blood concentrations and corresponding clinical responses need to be better examined. The purpose of this study was to describe daily dosages, measured blood concentrations, and clinical responses in critically ill patients. The purpose was also to contribute to establishing whole blood concentration reference values of the drugs investigated. Methods: A descriptive study of prospectively collected data from 302 admissions to a general intensive care unit (ICU) at a university hospital. Ten drugs (clonidine, fentanyl, morphine, dexmedetomidine, ketamine, ketobemidone, midazolam, paracetamol, propofol, and thiopental) were investigated, and daily dosages recorded. Blood samples were collected twice daily, and drug concentrations were measured. Clinical responses were registered using Richmond agitation-sedation scale (RASS) and Numeric rating scale (NRS). Results: Drug dosages were within recommended dose ranges. Blood concentrations for all 10 drugs showed a wide variation within the cohort, but only 3% were above therapeutic interval where clonidine (57 of 122) and midazolam (38 of 122) dominated. RASS and NRS were not correlated to drug concentrations. Conclusion: Using recommended dose intervals for analgesic and sedative drugs in the ICU setting combined with regular monitoring of clinical responses such as RASS and NRS leads to 97% of concentrations being below the upper limit in the therapeutic interval. This study contributes to whole blood drug concentration reference values regarding these 10 drugs.

EVALUATION OF IMMERSION IN EMULSIFIED ISOFLURANE OR PROPOFOL AS PART OF A TWO-STEP EUTHANASIA PROTOCOL IN MARBLED CRAYFISH (PROCAMBARUS VIRGINALIS).

The marbled crayfish (Procambarus virginalis) is a parthenogenetic invasive species across much of the world, and when found, euthanasia is often recommended to reduce spread to naïve ecosystems. Euthanasia recommendations in crustaceans includes a two-step method: first to produce nonresponsiveness and then to destroy central nervous tissue. Minimal data exist on adequate anesthetic or immobilization methods for crayfish. A population of 90 marbled crayfish was scheduled for euthanasia due to invasive species concerns. The population was divided into six treatment groups to evaluate whether immersion in emulsified isoflurane or propofol solutions could produce nonresponsiveness. Each group was exposed to one of six treatments for 1 h: isoflurane emulsified at 0.1%, 0.5%, 2%, 5%, and 15% or propofol at 10 mg/L and then increased to 100 mg/L. Crayfish from all treatment groups were moved to nonmedicated water after completion of 1 h and observed for an additional 4 h. All crayfish treated with isoflurane showed lack of a righting reflex at 5 min and loss of movement after 30 min. By 240 min (4 h), none of the crayfish from the isoflurane treatment groups regained movement. None of the crayfish in the propofol treatment achieved loss of reflexes or responsiveness, and all remained normal upon return to nonmedicated water. Isoflurane emulsified in water produces nonresponsiveness that is appropriate for the first step of euthanasia, while propofol was insufficient at these treatment doses.