Influence of general anaesthesia on circulating biomarkers of glucose metabolism in pigs

Pigs are widely used in metabolic research with procedures often requiring general anaesthesia. The aim was to investigate the effect of four different anaesthetic protocols: 1) isoflurane inhalation, 2) propofol infusion, 3) a mixture of tiletamine, zolazepam, medetomidine, ketamine and butorphanol (TZMKB)) and 4) ketamine combined with midazolam and xylazine (KMX)) on selected biomarkers during basal and glucose stimulated conditions. Eight domestic pigs were included in a cross-over design. Plasma concentrations of glucose, insulin, C-peptide, glucagon, cortisol, triglycerides, total cholesterol, aspartate amino transferase and alanine amino transferase, creatinine, urea, fructosamine, albumin, free fatty acids (FFAs) and glycerol were measured at baseline, during 2 h of anaesthesia and during 1 h of recovery. Intravenous glucose tolerance test (IVGTT, 0.5 g glucose/kg) was performed after 1 h of anaesthesia. Glucose disappearance rate and areas under the insulin, C-peptide and glucagon curves from the IVGTT were calculated. All four anaesthetic protocols affected glucose metabolism parameters significantly compared with un-anaesthetised pigs, which was particularly evident during IVGTT and for TZMKB and KMX anaesthesia. Propofol additionally influenced the plasma concentrations of triglycerides, FFAs and glycerol significantly. The remaining circulating biomarkers were largely unaffected by anaesthesia. These data underline the importance of considering the anaesthetic protocol in porcine studies of circulating metabolic biomarkers.

Operational outcomes of propofol sedation versus fentanyl, midazolam and diphenhydramine sedation for endoscopies and colonoscopies at an academic medical center

BACKGROUND

On July 1st, 2021, the University of Colorado Hospital (UCH) implemented new sedation protocols in the luminal gastrointestinal (GI) suite. GI proceduralist supervised, Nurse Administered Sedation with fentanyl, midazolam, and diphenhydramine (NAS) sedation was transitioned to Monitored Anesthesia Care with propofol under physician anesthesiologist supervision (MAC).

OBJECTIVE

To determine if there are statistically significant reductions in Sedation-Start to Scope-In time (SSSI) when using Monitored Anesthesia Care with propofol (MAC) versus Nurse Administered Sedation with fentanyl, midazolam, and diphenhydramine (NAS). Secondary objectives were to determine if statistically significant improvements to other operational times, quality measures, and satisfaction metrics were present.

METHOD

This study was a retrospective analysis of a natural experiment resultant of a change from NAS to MAC sedation protocols. Outcomes for NAS protocols from 1/1/21-6/30/21 were compared to outcomes of MAC protocols from the dates 8/1/21-10/31/21. Results were analyzed using Quasi-Poisson regression analysis and stratified based on upper GI, lower GI, and combined procedures. Patient demographic data including age, biological sex, comorbidities, and BMI, were adjusted for in the analysis. ASA matching was not performed as nursing sedation does not use ASA classifications. Pre-anesthesia co-morbidities were assessed via evaluation of a strict set of comorbidities abstracted from the electronic medical record. Perioperative operational outcomes include Sedation Start to Scope-In (SSSI), In-Room to Scope-In Time (IRSI), Scope Out to Out of Room (SOOR), Total Case Length (TCL), and Post Anesthesia Care Unit Length of Stay (PACU LOS). Quality outcomes include PACU Administered Medications (PAM), and Clinician Satisfaction Scores (CSS).

RESULTS

A total of 5,582 gastrointestinal (GI) endoscopic cases (upper, lower, and combined endoscopies) were observed. Statistically significant decreases in SSSI of 2.5, 2.1, and 2.2 minutes for upper, lower, and dual GI procedures were observed when using MAC protocols. A statistically significant increase in satisfaction scores of 47.0 and 19.6 points were observed for nurses and proceduralists, respectively, when using MAC.

CONCLUSION

MAC protocols for endoscopic GI procedures at UCH led to statistically significant decreases in the time required to complete procedures thus increasing operational efficiency.

Is assessment of skeletal muscle mass useful to predict time-to-awake in awake craniotomies?

Awake craniotomy is the gold standard for the resection of brain lesions near eloquent areas. For the commonly used asleep-awake-asleep technique, the patient must be awake and fully cooperative as soon as possible after discontinuation of anesthetics. A shorter emergence time is essential to decrease the likelihood of adverse events. Previous research found no relationship between body mass index (BMI) and time-to-awake for intravenous anesthesia with propofol, which is a lipophilic agent. As BMI cannot differentiate between fat and muscle tissue, we hypothesize that skeletal muscle mass, particularly when combined with BMI, may better predict time-to-awake from propofol sedation. We aimed to evaluate the relationship between skeletal muscle mass and the time-to-awake in patients undergoing awake craniotomy, as well as the interaction between skeletal muscle mass and BMI. In 260 patients undergoing an awake craniotomy, we used preoperative magnetic resonance imaging to assess temporalis muscle and cross-sectional skeletal muscle area of the masseter muscles and at level of the third cervical vertebra. Time-to-awake was dichotomized as ≤20 and >20 minutes. No association between various measures of skeletal muscle mass and time-to-awake was observed, and no interaction between skeletal muscle mass and BMI was found (all P > .05). Likewise, patients with a high BMI and low skeletal muscle mass (indicating an increased proportion of fat tissue) did not have a prolonged time-to-awake. Skeletal muscle mass did not predict time-to-awake in patients undergoing awake craniotomy, neither in isolation nor in combination with a high BMI.

Remimazolam-based anesthesia with flumazenil allows faster emergence than propofol-based anesthesia in older patients undergoing spinal surgery: A randomized controlled trial

BACKGROUND

Remimazolam is a novel, ultrashort-acting benzodiazepine that can be antagonized by flumazenil. This study aimed to determine whether remimazolam-based anesthesia with flumazenil provides a more rapid emergence than propofol-based anesthesia in older patients undergoing spinal surgery.

METHODS

This was a prospective, single-blind, randomized controlled trial. Forty-four patients > 75 years old who had undergone spinal surgery were enrolled in this study. They were randomly assigned to the remimazolam or propofol group (1:1) using a computer randomization system stratified by age and body weight. For anesthesia induction and maintenance, remifentanil was administered at a defined dose in both groups, and remimazolam or propofol was adjusted to maintain the bispectral index or state entropy monitoring within 40-60. All anesthetics were discontinued simultaneously after the postoperative X-ray and 0.5 mg flumazenil was administered to the remimazolam group. The primary outcome was extubation time after discontinuing anesthesia, and the secondary outcomes were time to eye opening, obeying commands, and achieving a white fast-track score (WFTS) of 12.

RESULTS

Thirty-nine patients were finally analyzed: remimazolam group (n = 20), propofol group (n = 19). There were no significant differences in intraoperative variables, such as operative time, anesthesia time, and patient background, between the 2 groups. Extubation times were significantly shorter in the remimazolam group than in the propofol group (4 vs 8 minutes, P < .001). The time to eye opening, obeying commands, and achieving a WFTS of 12 were significantly shorter in the remimazolam group (P < .001, for all comparisons).

CONCLUSION

Remimazolam-based anesthesia with flumazenil resulted in a faster emergence than propofol-based anesthesia in older patients undergoing spinal surgery.

A Deep Learning Framework for Anesthesia Depth Prediction from Drug Infusion History

In the target-controlled infusion (TCI) of propofol and remifentanil intravenous anesthesia, accurate prediction of the depth of anesthesia (DOA) is very challenging. Patients with different physiological characteristics have inconsistent pharmacodynamic responses during different stages of anesthesia. For example, in TCI, older adults transition smoothly from the induction period to the maintenance period, while younger adults are more prone to anesthetic awareness, resulting in different DOA data distributions among patients. To address these problems, a deep learning framework that incorporates domain adaptation and knowledge distillation and uses propofol and remifentanil doses at historical moments to continuously predict the bispectral index (BIS) is proposed in this paper. Specifically, a modified adaptive recurrent neural network (AdaRNN) is adopted to address data distribution differences among patients. Moreover, a knowledge distillation pipeline is developed to train the prediction network by enabling it to learn intermediate feature representations of the teacher network. The experimental results show that our method exhibits better performance than existing approaches during all anesthetic phases in the TCI of propofol and remifentanil intravenous anesthesia. In particular, our method outperforms some state-of-the-art methods in terms of root mean square error and mean absolute error by 1 and 0.8, respectively, in the internal dataset as well as in the publicly available dataset.

Use of a propofol infusion for anaesthetic maintenance in Guinea pigs (Cavia porcellus): a retrospective case series

OBJECTIVE

To retrospectively evaluate the feasibility of a propofol infusion for anaesthetic maintenance in guinea pigs.

STUDY DESIGN

Retrospective case series.

ANIMALS

Client-owned guinea pigs undergoing general anaesthesia.

METHODS

Anaesthetic records of guinea pigs anaesthetized between March 2015 and March 2018 were reviewed. Animals administered a propofol infusion for > 20 minutes were identified and evaluated. Procedure performed, pre-anaesthetic medication, preoperative and intraoperative respiratory rate (fR) and heart rates (HRs), total amount of propofol administered, total anaesthesia and recovery times were extracted from the records and analysed using descriptive statistics and Pearson correlation tests. Data are reported as mean (range).

RESULTS

Records of 14 animals meeting the criteria were identified. Following drug combinations were administered for premedication: butorphanol 0.43 (0.3-0.5) mg kg-1, medetomidine 0.1 (0.05-0.2) mg kg-1 and midazolam 1 (0.5-2) mg kg-1 (n = 3); methadone 0.33 (0.25-0.5) mg kg-1, medetomidine 0.07 (0.01-0.1) mg kg-1 and midazolam 0.66 (0.5-1) mg kg-1 (n = 3); butorphanol 0.5 mg kg-1, medetomidine 0.05 mg kg-1 and ketamine 5 mg kg-1 (n = 2); buprenorphine 0.01 mg kg-1, medetomidine 0.07 (0.04-1) mg kg-1 and ketamine 4 (3-5) mg kg-1 (n = 3); butorphanol 0.5 mg kg-1, alfaxalone 1 mg kg-1 and midazolam 0.5 mg kg-1 (n = 1); and methadone 0.38 (0.25-0.5) mg kg-1, medetomidine 0.08 (0.06-1) mg kg-1 with midazolam 0.75 (0.5-1) mg kg-1 (n = 2). Preoperative and intraoperative HRs were 240 (160-300) and 170 (140-200) beats minute-1, respectively. Preoperative and intraoperative fR were 63 (50-86) and 37 (18-80) breaths minute-1, respectively. The propofol infusion rate was 0.45 (0.17-0.80) mg kg-1 minute-1. Total anaesthesia and recovery times were 60 (25-145) and 17 (8-60) minutes, respectively. A slight correlation was found between total propofol dose infused and recovery time (r = 0.58).

CONCLUSION AND CLINICAL RELEVANCE

Propofol infusions may be a useful alternative to inhalant anaesthetics.

Comparison of two sedation protocols, with and without analgesia, in pigs: Assessment of sedation end points and propofol requirements

OBJECTIVE

To compare the effects of intramuscular premedication with a novel nonanalgesic [alfaxalone-midazolam-acepromazine (AMA)] and an analgesic [ketamine-midazolam-detomidine (KMD)] protocol on sedation end points and propofol requirements for induction of anesthesia in swine.

STUDY DESIGN

Prospective experimental study.

ANIMALS

A total of 27 Yorkshire cross gilts weighing approximately 30 kg.

METHODS

Two sedation protocols, AMA and KMD, were compared. Time from intramuscular injection to ataxia, recumbency and nonresponsiveness to tactile stimulation was recorded. The propofol dose requirement for induction of general anesthesia and tracheal intubation, and any adverse events (paddling, twitching), were recorded. Data were tested for normality using a Shapiro-Wilk test. Propofol requirements were compared using a Student's t test. Times from injection to sedation end points were compared using a Mood's test, and significance was confirmed using a Kaplan-Meier curve with Wilcoxon test survival analysis.

RESULTS

Sedation end points were reached significantly faster with KMD than with AMA. Nonresponsiveness occurred in 5 (0-16) and 9.5 (5-36) minutes for KMD and AMA, respectively (p = 0.011). No significant difference (p = 0.437) was found between propofol doses used in either group (KMD; 64.38 ± 5.98 mg, AMA; 72.00 ± 7.57 mg). More adverse events were noted with AMA (11/16 pigs) than with KMD (1/11 pigs).

CONCLUSIONS AND CLINICAL RELEVANCE

In pigs, AMA can be used as a reliable sedation protocol. Frequency of adverse events and time to reach sedation end points between AMA and KMD differed, but the dose of propofol needed to induce general anesthesia was not significantly different.

Safety and efficacy of target-controlled infusion versus intermittent bolus administration of propofol for sedation in colonoscopy: a randomized controlled trial

BACKGROUND

Our objective was to compare the safety and efficacy of Target-Controlled Infusion (TCI) versus intermittent bolus of propofol for colonoscopy sedation.

METHODS

We conducted a randomized (1:1), single-blind, parallel-group superiority trial with fifty ASA I or II patients, both sexes, aged 18 to 65 years, Body Mass Index ≤ 30 kg.m-2, undergoing colonoscopy, allocated to receive propofol by TCI (effect-site, 2 μg.mL-1 plus 0.5 μg.mL-1 until unconsciousness and as necessary for agitation) or intermittent bolus (1 mg.kg-1 plus 0.5 mg.kg-1 every 5 minutes or as above). The primary safety outcome was the need for airway maneuvers and the primary efficacy outcome was the need for interventions to adjust the level of sedation. Secondary outcomes included incidence of agitation, propofol dose, and time to recovery.

RESULTS

The median (IQR) number of airway maneuvers and interventions needed to adjust sedation was 0 (0‒0) vs. 0 (0‒0) (p = 0.239) and 1 (0‒1) vs. 3 (1‒4) (p < 0.001) in the TCI and control groups, respectively. Agitation was more common in the intermittent bolus group ‒ 2 (0‒2) vs. 1 (0‒1), p < 0.001. The mean ± SD time to recovery was 4.9 ± 1.4 minutes in the TCI group vs. 2.3 ± 1.6 minutes in the control group (p < 0.001). The total propofol dose was higher in the TCI group (234 ± 46 µg.kg-1.min-1 vs. 195 ± 44 µg.kg-1.min-1 (p = 0.040)).

CONCLUSIONS

During colonoscopy, TCI is as safe as intermittent bolus of propofol while reducing the incidence of agitation and the need for dose adjustments. However, intermittent bolus administration was associated with lower total propofol dose and earlier recovery.

The preventive effect of 5-hydroxytryptamine-3 receptor antagonist on blood pressure reduction and postoperative nausea and vomiting during general anesthesia induction: A double-blinded, randomized controlled trial

STUDY OBJECTIVE

Administering a 5-hydroxytryptamine-3 receptor (5-HT3) at anesthesia induction may aid in achieving hemodynamic stability during general anesthesia induced using opioids. Therefore, we aimed to evaluate the effect of ramosetron, a 5-HT3 antagonist, administered on hypotension at the induction of total intravenous anesthesia (TIVA) with propofol and remifentanil. Additionally, we aimed to compare the impact of ramosetron administration at anesthesia induction versus that at the end of the surgery on postoperative nausea and vomiting (PONV).

DESIGN

Patients were randomly allocated to the Induction group (administration of ramosetron [0.3 mg/5 ml] at anesthesia induction and normal saline [5 ml] at the end of the surgery) or End group (administration of normal saline [5 ml] at anesthesia induction and ramosetron [0.3 mg/5 ml] at the end of the surgery). Hemodynamic status, PONV, and postoperative pain were assessed.

SETTING

Operating room, post-anesthetic care unit, and general ward.

PATIENTS

In total, 176 non-smoking patients without any past medical history undergoing laparoscopic gynecological surgeries under TIVA were included in the study.

MEASUREMENTS

Blood pressure (BP), heart rate, PONV, visual analog scale (VAS).

MAIN RESULTS

The Induction group exhibited significantly higher BP at anesthesia induction and required significantly lower doses of phenylephrine and ephedrine during anesthesia than the End group had. However, PONV and postoperative pain were similar between the two groups.

CONCLUSIONS

Administering ramosetron at anesthesia induction resulted in significantly better hemodynamic stability with significantly lesser requirement of phenylephrine and ephedrine than administering at the end of the surgery did. Therefore, we recommend ramosetron administration at anesthesia induction rather than at the end of the surgery to prevent PONV and the decrease in the mean BP during TIVA with propofol and remifentanil.

Total Intravenous Anaesthesia <em>vs</em>. Inhalational Agents in a Patient with Autoimmune Liver Disease

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Predictors for delayed awakening in adult glioma patients receiving awake craniotomy under monitored anesthesia care

PURPOSE

Delayed awakening after anesthetic discontinuation during awake craniotomy is associated with somnolence during functional brain mapping. However, predictors of delayed awakening in patients receiving monitored anesthesia care for awake craniotomy are unknown.

METHODS

This retrospective cohort study analyzed 117 adult patients with supratentorial glioma in or near eloquent areas who received monitored anesthesia care for awake craniotomy between July 2020 and January 2023 at Linkou Chang Gung Memorial Hospital. These patients were divided into two groups according to their time to awakening (ability to speak their names) after propofol cessation: longer or shorter than 20 min (median duration). Because propofol was solely used anesthetic from skin incision to dural opening, parameters in Schnider model for propofol target-controlled infusion, such as age, sex, and BMI, were adjusted or propensity-matched to compare their anesthetic, surgical, and histopathological profiles.

RESULTS

After propensity-matched comparisons of age and BMI, significant predictors of delayed awakening included IDH1 wild-type tumors and repeated craniotomies. Subgroup analysis revealed that older age and larger T2 volume were predictors in patients undergoing the first craniotomy, while lower preoperative Karnofsky performance scale scores and depression were predictors in repeated craniotomy cases. Delayed awakening was also associated with somnolence and a lower gross total resection rate.

CONCLUSION

Our retrospective analysis of patients receiving monitored anesthesia care for awake craniotomy revealed that delayed awakening after propofol discontinuation occurred more often in patients with IDH1 wild-type tumors and repeated craniotomies. Also, delayed awakening was associated with somnolence during functional mapping and a lower gross total resection rate.

Trends and Differences in Status Epilepticus Treatment of Children and Adults Over 10 Years: A Comparative Study of Medical Records (2012-2021) from a University Hospital in Germany

BACKGROUND AND OBJECTIVES

Over the last decade, significant advancements have been made in status epilepticus (SE) management, influenced by landmark trials such as ESETT and RAMPART. The objectives of this study were to explore the evolution of drug treatments for patients with SE, to investigate its association with outcomes and mortality, and to evaluate differences in treatment patterns between adults and children for a potential shift in medication trends due to the above mentioned trials.

METHODS

The medical records of patients with SE treated at University Hospital Frankfurt between 2012 and 2021 were evaluated for medication trends and outcomes. Children and adults were analyzed separately and jointly.

RESULTS

This study included 1151 SE episodes in 1021 patients (mean age = 53.3 ± 28.3 years; 52.5 % female [n = 533]). The overall percentage of patients with SE treated prehospital was stable over the last decade. More than half (53.6 %) of children were treated prehospital, compared with less than one-third (26.7 %) of adults. Prehospital midazolam use increased over time, while diazepam use decreased. Lorazepam was the most commonly used benzodiazepine in hospitals in 2012-2013, used in 40.8 % of all episodes. However, its use declined to 27.2 % in 2020-2021, while midazolam use increased to 44.0 %. While the use of older antiseizure medications (ASMs) such as phenobarbital (p = 0.02), phenytoin (p < 0.001), and valproate (p < 0.001) decreased, the use of newer ASMs such as levetiracetam and lacosamide significantly increased (p < 0.001). Propofol and continuous midazolam infusion remained the most used third-line therapy drugs. Overall mortality was 16.5 % at discharge and 18.9 % at 30 days. Mortality rates did not change between 2012 and 2021.

CONCLUSION

Midazolam has become the preferred benzodiazepine in pre- and in-hospital settings, both in children and adults. The same applies to the increased use of levetiracetam and lacosamide over time in children and adults, while phenobarbital, phenytoin, and valproate use decreased. Continuous midazolam infusion and propofol remain the most frequently used anesthetic drugs. Mortality and outcome remain stable despite changes in medication patterns.

Does Propofol Effect Site (Brain) Concentration Predicted by Target-Controlled Infusion Correlate with Propofol Measured in the Brain? An Exploratory Study in Neurosurgical Patients

BACKGROUND

Total intravenous anesthesia with propofol can be administered by target-controlled infusion pumps, which work on the principles of pharmacokinetic modeling. While designing this model, neurosurgical patients were excluded as the surgical site and drug action site remained the same (brain). Whether the predicted set propofol concentration and the actual brain site concentration correlate, especially in neurosurgical patients with impaired blood-brain barrier (BBB), is still unknown. In this study we compared the set propofol effect-site concentration in the target-controlled infusion pump with actual brain concentration measured by sampling the cerebrospinal fluid (CSF).

METHODS

Consecutive adult neurosurgical patients requiring propofol infusion intraoperatively were recruited. Blood and CSF samples were collected simultaneously when patients received propofol infusion at 2 different target effect-site concentrations-2 and 4 ug/mL. To study BBB integrity, CSF-to-blood albumin ratio and imaging findings were compared. The propofol level in the CSF was compared with set concentration using the Wilcoxon signed-rank test.

RESULTS

Fifty patients were recruited, and the data were analyzed from 43 patients. There was no correlation between propofol concentration set in TCI and propofol concentration measured in blood and CSF. Though imaging findings were suggestive of BBB disruption in 37/43 patients, the mean (±standard deviation) CSF-to-serum albumin ratio was 0.0028 ± 0.002, suggesting intact BBB integrity (ratio >0.3 was considered as disrupted BBB).

CONCLUSIONS

CSF propofol level did not correlate with set concentration in spite of acceptable clinical anesthetic effect. Also, the CSF-to-blood albumin measurement did not provide information on the BBB integrity.

Appraisal of Postoperative Outcomes of Volatile and Intravenous Anesthetics: A Network Meta-Analysis of Patients Undergoing Cardiac Surgery

OBJECTIVES

To determine the relative efficacy of specific regimens used as primary anesthetics, as well as the potential combination of volatile and intravenous anesthetics among patients undergoing cardiac, thoracic, and vascular surgery.

DESIGN

This frequentist, random-effects network meta-analysis was registered prospectively (CRD42022316328) and conducted according to the PRISMA-NMA framework. Literature searches were conducted up to April 1, 2022 across relevant databases. Risk of bias (RoB) and confidence of evidence were assessed by RoB-2 and CINeMA, respectively. Pooled treatment effects were compared with propofol monotherapy.

SETTING

Fifty-three randomized controlled trials (N = 8,085) were included, of which 46 trials (N = 6,604) enrolled patients undergoing cardiac surgery.

PARTICIPANTS

Trials enrolling adults (≥18) undergoing cardiac, thoracic, and vascular surgery, using the same induction regimens, and comparing volatile and/or total intravenous anesthesia for the maintenance of anesthesia. Given that the majority of trials focused on those undergoing cardiac surgery and the heterogeneity, analyses were restricted to this population.

MEASUREMENT AND MAIN RESULTS

Outcomes of interest included intensive care unit (ICU) length of stay (LOS), myocardial infarction, in-hospital and 30-day mortality, stroke, and delirium. Across 19 trials (N = 1,821; 9 arms; I2 = 64.5%), sevoflurane combined with propofol decreased ICU LOS (mean difference [MD] -18.26 hours; 95% CI -34.78 to -1.73 hours), whereas midazolam with propofol (MD 17.51 hours; 95% CI 2.78-32.25 hours) was associated with a significant increase in ICU LOS, when compared with propofol monotherapy. Among 27 trials (N = 4,080; 10 arms; I2 = 0%), midazolam was associated with significantly greater risk of myocardial infarction versus propofol (risk ratio 1.94; 95% CI 1.01-3.71). There were no significant differences across other outcomes.

CONCLUSION

In patients undergoing cardiac surgery, sevoflurane with propofol was associated with decreased ICU LOS compared with propofol monotherapy. Midazolam with propofol increased ICU LOS compared with propofol alone. The combined use of intravenous and volatile anesthetics should be explored further. Future trials in thoracic and vascular surgery are warranted.

Comparison of Remimazolam and Propofol for Drug-Induced Sleep Endoscopy: A Randomized Clinical Trial

OBJECTIVE

To compare the efficacy and safety of remimazolam with those of propofol for drug-induced sleep endoscopy (DISE) in patients with obstructive sleep apnea-hypopnea syndrome (OSAHS).

STUDY DESIGN

A prospective, single-center, randomized clinical trial.

SETTING

Xiangya Hospital of Central South University.

METHODS

Patients with OSAHS receiving DISE were randomly assigned to either the remimazolam or propofol group. The primary outcome was the incidence of hypoxemia (pulse oxygen saturation [SpO2 ] < 90%) during DISE. The secondary outcomes were the incidence of severe hypoxemia (SpO2  < 80%), the minimal value of SpO2 , sedation success rate (completion of DISE according to the medication regimen), and incidence of events of interest (including injection pain, bradycardia, and decreased respiratory rate).

RESULTS

Sixty-four patients were included in this study. The incidence of hypoxemia was significantly lower in the remimazolam than in the propofol group (25.00% vs 62.50%, respectively; relative risk, 0.40; 95% confidence interval [CI], 0.20-0.74; p < .01). There was no significant difference in the sedation success rate between the remimazolam and propofol groups (96.88% vs 81.25%, respectively; relative risk, 1.19; 95% CI, 1.01-1.50; p = .10). The incidence of at least 1 event of interest was lower in the remimazolam than in the propofol group (43.75% vs 96.88%, respectively; relative risk, 0.45; 95% CI, 0.29-0.63; p < .01).

CONCLUSION

Remimazolam can present satisfactory sedative efficacy in DISE, with a lower incidence of hypoxemia and a higher safety profile than propofol.

Comparison of anesthetic effects of different doses of alfentanil combined with ciprofol in elderly patients undergoing ERCP: a randomized controlled trial

BACKGROUND AND OBJECTS

Patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) are often old and poor in physical fitness. The purpose of this study was to investigate the anesthetic effect of different doses of alfentanil combined with ciprofol in elderly patients undergoing endoscopic retrograde cholangiopancreatography (ERCP).

METHODS

In this clinical trial, 137 patients, who were candidates for ERCP were randomly divided into three groups. Group A were given 0.15 μg/kg/min of alfentanil in maintenance stage, Group B were given 0.25 μg/kg/min and Group C were given 0.35 μg/kg/min. Mean arterial pressure (MAP), heart rate (HR), oxygen saturation (SpO2) of the patients at each time point including the entry into the operation room (T0), at the beginning of surgery(T1), 10 min after surgery(T2), 20 min after surgery(T3), 30 min after surgery(T4),endoscopy withdrawal (T5) were recorded. Adverse events(including respiratory depression, body movement and hypoxemia),the dosage of ciprofol, the time of operation time and awakening were recorded.

RESULTS

Compared with Group A, MAP and HR in Group B and Group C was decreased during T1-T5 (P < 0.05). Compared with group B, MAP and HR in group C was decreased during T1-T5 (P < 0.05). Compared with Group A and Group C,the number of adverse reactions of Group B was decreased(P < 0.05). There was no statistical difference in surgical time among the three groups(P > 0.05),but a statistically significant difference in recovery time (P < 0.05).

CONCLUSION

The adverse events of alfentanil 0.25μg/kg/min combined with ciprofol were low, and the anesthetic effect was the best.

Application of surgical pleth index in the opioid-free anesthesia: A randomized controlled trial

BACKGROUND

Currently, there is no gold standard for monitoring noxious stimulation during surgery, and the surgical pleth index (SPI) is only one of many monitoring methods. It is commonly used in the monitoring of conventional opiate anesthesia, but its effectiveness in opioid-free anesthesia (OFA) has not been evaluated. Therefore, the aim of this study was to observe the guidance value of the surgical pleth index in opioid-free anesthesia for patients undergoing lower abdominal or pelvic surgery.

METHODS

A total of 122 patients who underwent lower abdominal or pelvic surgery in our hospital between March 2021 and July 2022 were selected and equally divided into OFA (F) and control (C) groups according to the random number table method. Both groups underwent ultrasound-guided unilateral/bilateral quadratus lumborum block in the supine position according to the surgical field. In group F, 0.50% lidocaine and 0.20% ropivacaine (in 20 mL of 0.9% normal saline) were injected on each side. In group C, 20 mL 0.9% normal saline was injected on each side. Group F received general anesthesia without opioids and group C received general anesthesia with opioids. BP, pulse oxygen saturation, PETCO2, reactionentropy, stateentropy, and SPI values; Steward score; dosage of propofol, dexmedetomidine, rocuronium, and diltiazem; extubation time; and awake time were monitored in both groups.

RESULTS

There were no significant differences in the general data between the 2 groups (P > .05). There were no significant differences in SPI values at T0, T1, T2, T3, T4, and T5 or the number of cases requiring additional remifentanil, propofol, and diltiazem between the 2 groups (P > .05). The stateentropy, reactionentropy, and Steward scores were higher in group F than in group C at T4 and T5, while the extubation and awake times were lower in group F than in group C (P < .05). The heart rate and SPI of group F were lower than that of group C at T3 (P < .05).

CONCLUSION

The guiding value of SPI in OFA was similar to its use in opiated anesthesia. Its clinical efficacy is exact, vital signs are stable, enabling rapid, and complete regaining of consciousness.

A preclinical study on online monitoring of exhaled ciprofol concentration by the ultraviolet time-of-flight spectrometer and prediction of anesthesia depth in beagles

BACKGROUND

Exhaled air has been demonstrated as a reliable medium for monitoring propofol concentration. However, online monitoring of exhaled ciprofol have not been reported.

METHODS

Thirty-six beagles undergoing mechanical ventilation were divided into 6 groups, including bolus injection of low (Group BL, n = 6), medium (Group BM, n = 6), and high dose of ciprofol (Group BH, n = 6) groups; as well as 1 h continuous infusion of low (Group IL, n = 6), medium (Group IM, n = 6), and high dose of ciprofol (Group IH, n = 6) groups. The ciprofol concentration in exhaled air (CE) was determined by the ultraviolet time-of-flight mass spectrometer (UV-TOFMS). The correlations of CE and plasma concentration (Cp), CE and the bispectral index (BIS) were explored. Additionally, the pharmacokinetics (PK) models of CE and Cp, the pharmacodynamics (PD) models of CE and BIS were also established.

RESULTS

Online monitoring of exhaled ciprofol can be achieved with the UV-TOFMS instrument. The CE of ciprofol in beagles was found at parts per billion by volume (ppbv) level. The linear correlation of CE and Cp was weak in bolus injection groups (R2 = 0.01) nonetheless moderate in continuous infusion groups (R2 = 0.53). The i.v. bolus PK model of CE and Cp can be fitted with the non-compartment models. Additionally, the the PD models of CE and BIS can be well fitted with the inhibitory sigmoid Emax model with the estimate values of IC50 = 0.05 ± 0.01 ppbv, γ = 4.74 ± 1.51, E0 = 81.40 ± 3.75, Imax = 16.35 ± 4.27 in bolus injection groups; and IC50 = 0.05 ± 0.01 ppbv, γ = 6.92 ± 1.30, E0 = 83.08 ± 1.62, Imax = 12.58 ± 1.65 in continuous infusion groups.

CONCLUSIONS

Online monitoring of exhaled ciprofol concentration in beagles can be achieved with the UV-TOFMS instrument. Good correlations can be observed between exhaled ciprofol concentration and its cerebral effects reflected by the BIS value, demonstrating the potential of exhaled ciprofol monitoring for titrating depth of anesthesia in future clinical setting.

Effect of acute normovolemic hemodilution on anesthetic effect, plasma concentration, and recovery quality in elderly patients undergoing spinal surgery

OBJECTIVE

To explore the effect of acute normovolemic hemodilution (ANH) on the anesthetic effect, plasma concentration, and postoperative recovery quality in elderly patients undergoing spinal surgery.

METHODS

A total of 60 cases of elderly patients aged 65 to 75 years who underwent elective multilevel spinal surgery were assigned randomly into the ANH group (n = 30) and control group (n = 30). Hemodynamic and blood gas analysis indexes were observed and recorded before ANH (T1), after ANH (T2), immediately after postoperative autologous blood transfusion (T3), 10 min (T4), 20 min (T5), 30 min (T6), 40 min (T7), and 50 min (T8) after the transfusion, and at the end of the transfusion (i.e., 60 min; T9). At T3 ~ 9, bispectral index (BIS) and train-of-four (TOF) stimulation were recorded and the plasma propofol/cisatracurium concentration was determined. The extubation time and recovery quality were recorded.

RESULTS

The ANH group presented a lower MAP value and a higher SVV value at T2, and shorter extubation and orientation recovery time (P < 0.05) compared with the control group. BIS values at T8 and T9 were lower in the ANH group than those in the control group (P < 0.05). TOF values at T7 ~ 9 were lower in the ANH group than those in the control group (P < 0.05). There were no statistically significant differences in the postoperative plasma concentrations of propofol and cisatracurium between the groups (P > 0.05).

CONCLUSION

During orthopedic surgery, the plasma concentration of elderly patients is increased after autologous blood transfusion of ANH, and the depth of anesthesia and muscle relaxant effect are strengthened, thus leading to delayed recovery of respiratory function and extubation.

A synopsis of multitarget therapeutic effects of anesthetics on depression

Depression is a profound mental disorder that dampens the mood and undermines volition, which exhibited an increased incidence over the years. Although drug-based interventions remain the primary approach for depression treatment, the available medications still can't satisfy the patients. In recent years, the newly discovered therapeutic targets such as N-methyl-D-aspartate (NMDA) receptor, α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor, and tyrosine kinase B (TrkB) have brought new breakthroughs in the development of antidepressant drugs. Moreover, it has come to light that certain anesthetics possess pharmacological mechanisms intricately linked to the aforementioned therapeutic targets for depression. At present, numerous preclinical and clinical studies have explored the therapeutic effects of anesthetic drugs such as ketamine, isoflurane, N2O, and propofol, on depression. These investigations suggested that these drugs can swiftly ameliorate patients' depression symptoms and engender long-term effects. In this paper, we provide a comprehensive review of the research progress and potential molecular mechanisms of various anesthetic drugs for depression treatment. By shedding light on this subject, we aim to facilitate the development and clinical implementation of new antidepressant drugs based on anesthetic medications.

Effect of raw electroencephalogram-guided anesthesia administration on postoperative outcomes in elderly patients undergoing abdominal major surgery: a randomized controlled trial

BACKGROUND

EEG monitoring techniques are receiving increasing clinical attention as a common method of reflecting the depth of sedation in the perioperative period. The influence of depth of sedation indices such as the bispectral index (BIS) generated by the processed electroencephalogram (pEEG) machine to guide the management of anesthetic depth of sedation on postoperative outcome remains controversial. This research was designed to decide whether an anesthetic agent exposure determined by raw electroencephalogram (rEEG) can influence anesthetic management and cause different EEG patterns and affect various patient outcomes.

METHODS

A total of 141 participants aged ≥ 60 years undergoing abdominal major surgery were randomized to rEEG-guided anesthesia or routine care group. The rEEG-guided anesthesia group had propofol titrated to keep the rEEG waveform at the C-D sedation depth during surgery, while in the routine care group the anesthetist was masked to the patient's rEEG waveform and guided the anesthetic management only through clinical experience. The primary outcome was the presence of postoperative complications, the secondary outcomes included intraoperative anesthetic management and different EEG patterns.

RESULTS

There were no statistically significant differences in the occurrence of postoperative respiratory, circulatory, neurological and gastrointestinal complications. Further EEG analysis revealed that lower frontal alpha power was significantly associated with a higher incidence of POD, and that rEEG-guidance not only reduced the duration of deeper anesthesia in patients with lower frontal alpha power, but also allowed patients with higher frontal alpha power to receive deeper and more appropriate depths of anesthesia than in the routine care group.

CONCLUSIONS

In elderly patients undergoing major abdominal surgery, rEEG-guided anesthesia did not reduce the incidence of postoperative respiratory, circulatory, neurological and gastrointestinal complications. rEEG-guided anesthesia management reduced the duration of intraoperative BS in patients and the duration of over-deep sedation in patients with lower frontal alpha waves under anesthesia, and there was a strong association between lower frontal alpha power under anesthesia and the development of POD. rEEG-guided anesthesia may improve the prognosis of patients with vulnerable brains by improving the early identification of frail elderly patients and providing them with a more effective individualized anesthetic managements.

Transient reactive phlebitis and intravenous ciprofloxacin: Is there an association?

Transient reactive phlebitis (TRP) is a rare adverse event seen with intravenous infusion of medications. It is characterised by the appearance of erythematous cord-like lesions along the superficial veins proximal to the site of infusion. It is rarely seen with drugs such as morphine, rocuronium, eptifibatide, propofol and vancomycin. The exact pathogenesis is not clear; however, certain proposed mechanisms are due to the direct activation of C-nociceptors, activation of the kallikrein-kinin system with bradykinin release, local mediator release or histamine release. Here, we report a case of TRP due to ciprofloxacin infusion.

Comparison of different ratios of propofol-ketamine admixture in rapid-sequence induction of anesthesia for emergency laparotomy: a randomized controlled trial

BACKGROUND

We aimed to compare the hemodynamic effect of two ratios of propofol and ketamine (ketofol), namely 1:1 and 1:3 ratios, in rapid-sequence induction of anesthesia for emergency laparotomy.

METHODS

This randomized controlled study included adult patients undergoing emergency laparotomy under general anesthesia. The patients were randomized to receive either ketofol ratio of 1:1 (n = 37) or ketofol ratio of 1:3 (n = 37). Hypotension (mean arterial pressure < 70 mmHg) was managed by 5-mcg norepinephrine. The primary outcome was total norepinephrine requirements during the postinduction period. Secondary outcomes included the incidence of postinduction hypotension, and the intubation condition (excellent, good, or poor).

RESULTS

Thirty-seven patients in the ketofol-1:1 and 35 patients in the ketofol 1:3 group were analyzed. The total norepinephrine requirement was less in the ketofol-1:1 group than in the ketofol-1:3 group, P-values: 0.043. The incidence of postinduction hypotension was less in the ketofol-1:1 group (4 [12%]) than in ketofol-1:3 group (12 [35%]), P-value 0.022. All the included patients had excellent intubation condition.

CONCLUSION

In patients undergoing emergency laparotomy, the use of ketofol in 1:1 ratio for rapid-sequence induction of anesthesia was associated with less incidence of postinduction hypotension and vasopressor consumption in comparison to the 1:3 ratio with comparable intubation conditions.

CLINICAL TRIAL REGISTRATION

NCT05166330. URL: https://clinicaltrials.gov/ct2/show/NCT05166330 .

Postoperative nausea and vomiting after artificial joint replacement surgery: comparison between remimazolam and sevoflurane, a propensity score analysis

PURPOSE

Remimazolam, a newly synthesized ultrashort-acting benzodiazepine, has not been previously compared with sevoflurane with regard to postoperative nausea and vomiting (PONV). The aim of this study is to investigate the incidence of PONV between remimazolam and sevoflurane among patients undergoing artificial joint replacement surgery.

METHODS

We conducted a retrospective analysis of the electronic medical records of patients who underwent artificial joint replacement surgery at Kobe City Medical Center General Hospital from 2020 to 2022, with a focus on comparing the incidence of PONV among those who received sevoflurane versus remimazolam anesthesia. To control for confounding factors, we employed a propensity score-matching technique to pair patients who received sevoflurane anesthesia with those who received remimazolam anesthesia.

RESULTS

The records of 292 patients receiving general anesthesia for artificial joint replacement surgery were collected and categorized into group sevoflurane (n = 241) or group remimazolam (n = 51). Before propensity score matching, age and ASA-PS exhibited significant differences between two groups. There was no significant difference in the incidence of PONV between them (p = 0.461). After matching, there were 51 patients in each group. However, there is no significant difference in the incidence of PONV between the two matched cohorts (p = 0.243).

CONCLUSIONS

This study demonstrated that there was no difference in the prevalence of PONV between remimazolam and sevoflurane anesthesia in patients undergoing artificial joint replacement surgery.

Modified Manual Chest Compression for Prevention and Treatment of Respiratory Depression in Patients Under Deep Sedation During Upper Gastrointestinal Endoscopy: Two Randomized Controlled Trials

BACKGROUND

We aimed to determine the preventive and therapeutic efficacy of modified manual chest compression (MMCC), a novel noninvasive and device-independent method, in reducing oxygen desaturation events in patients undergoing upper gastrointestinal endoscopy under deep sedation.

METHODS

A total of 584 outpatients who underwent deep sedation during upper gastrointestinal endoscopy were enrolled. In the preventive cohort, 440 patients were randomized to the MMCC group (patients received MMCC when their eyelash reflex disappeared, M1 group) or control group (C1 group). In the therapeutic cohort, 144 patients with oxygen desaturation of a Sp o2 < 95% were randomized to MMCC group (patients who subsequently received MMCC, M2 group) or the conventional treatment group (C2 group). The primary outcomes were the incidence of desaturation episodes with an Sp o2 < 95% for the preventive cohort and the time spent below 95% Sp o2 for the therapeutic cohort. Secondary outcomes included the incidence of gastroscopy withdrawal and diaphragmatic pause.

RESULTS

In the preventive cohort, MMCC reduced the incidence of desaturation episodes <95% (14.4% vs 26.1%; RR, 0.549; 95% confidence interval [CI], 0.37-0.815; P = .002), gastroscopy withdrawal (0% vs 2.29%; P = .008), and diaphragmatic pause at 30 seconds after propofol injection (74.5% vs 88.1%; RR, 0.846; 95% CI, 0.772-0.928; P < .001). In the therapeutic cohort, patients who received MMCC had a significantly shorter time spent below 95% Sp o2 (40 [20-69] seconds vs 91 [33-152] seconds, median difference [95% CI], -39 [-57 to -16] seconds, P < .001), a lower incidence of gastroscopy withdrawal (0% vs 10.4%, P = .018), and more enhanced diaphragmatic movement at 30 seconds after Sp o2 <95% (1.11 [0.93-1.4] cm vs 1.03 [0.7-1.24] cm; median difference [95% confidence interval], 0.16 [0.02-0.32] cm; P = .015).

CONCLUSIONS

MMCC may exert preventive and therapeutic effects against oxygen desaturation events during upper gastrointestinal endoscopy.

Propofol-based intravenous anesthesia is associated with improved survival outcomes after major cancer surgery: a nationwide cohort study in South Korea

BACKGROUND

The optimal anesthetic technique for cancer surgery remains a controversial issue. This study aimed to examine whether propofol-based total intravenous anesthesia (TIVA) was associated with survival outcomes after major cancer surgery in South Korea and compare its effectiveness with that of inhalation anesthesia.

METHODS

This nationwide population-based cohort study included adult patients who were admitted to the hospital and underwent major cancer surgery between January 1, 2016, and December 31, 2020. The major cancers included lung, gastric, colorectal, esophageal, small bowel, liver, pancreatic, and bile duct or gallbladder cancers.

RESULTS

A total of 253,003 patients who underwent major cancer surgery were included in the analysis. After propensity score (PS) matching, 115,370 patients (57,685 in each group) were included in the final analysis. In the PS-matched cohort, the TIVA group showed 9% (hazard ratio [HR]: 0.91, 95% CI [0.85, 0.98], P = 0.018) and 7% (HR: 0.93, 95% CI [0.89, 0.96], P < 0.001) lower 90-day and one-year mortality rates, respectively, than the inhalation group. In subgroup analyses, the TIVA group showed lower 90-day mortality than the inhalation group in the gastric (HR: 0.86, 95% CI [0.72, 0.97], P = 0.033), colorectal (HR: 0.64, 95% CI [0.56, 0.73], P < 0.001), and pancreatic (HR: 0.76, 95% CI [0.57, 0.94], P = 0.038) cancer surgery groups.

CONCLUSIONS

Propofol-based TIVA is associated with better survival outcomes after major cancer surgeries. Moreover, propofol-based TIVA was beneficial in patients who underwent gastric, colorectal, and pancreatic cancer surgeries.

Remimazolam: a randomized controlled study of its suitability for insertion of a supraglottic airway

PURPOSE

Loss of motor response to thrusting the jaw forward is a useful indicator for uncomplicated insertion of a supraglottic airway. The aim of this study was to assess the suitability of remimazolam for insertion of a supraglottic airway assessed by loss of response to jaw thrusting.

METHODS

Seventy patients, who were scheduled for elective surgeries under general anesthesia, were allocated randomly to one of two groups. In one group (remimazolam group), remimazolam was infused 12 mg kg-1 h-1 (50 mg maximum), and in the other (propofol group), propofol was infused at 120 mg kg-1 h-1 (500 mg maximum). Once the eyelash reflex disappeared, response to jaw thrusting was assessed. Primary outcome measure was the proportion of patients with loss of response to jaw thrusting before reaching the maximum dose of the test drug. We planned an interim analysis (of one time) after 40 patients, using the Pocock adjustment method.

RESULTS

From the interim analysis results, the study was stopped after recruitment of 40 patients. Loss of response to jaw thrusting was observed in all of 21 patients (100%) in the propofol group, and in 9 of 19 patients (47%) in the remimazolam group. There was a significant difference in the proportion between the groups (P = 0.0001, 95% CI for difference 30-75%).

CONCLUSION

Remimazolam frequently does not inhibit response to jaw thrusting, and thus remimazolam is not a suitable induction agent for uncomplicated insertion of a supraglottic airway unless either a neuromuscular blocking agent or an opioid is co-administered.

Efficacy of intraoperative thoracoscopic intercostal nerve blocks in nonintubated and intubated video-assisted thoracic surgery: A randomized study

BACKGROUND

The efficacy of thoracoscopic intercostal nerve blocks (TINBs) for noxious stimulation from video-assisted thoracic surgery (VATS) remains unclear. The efficacy of TINBs may also be different between nonintubated VATS (NIVATS) and intubated VATS (IVATS). We aim to compare the efficacy of TINBs on analgesia and sedation for NIVATS and IVATs intraoperatively.

METHODS

Sixty patients randomized to the NIVATS or IVATS group (30 each) received target-controlled propofol and remifentanil infusions, with bispectral index (BIS) maintained at 40-60, and multilevel (T3-T8) TINBs before surgical manipulations. Intraoperative monitoring data, including pulse oximetry, mean arterial pressure (MAP), heart rate, BIS, density spectral arrays (DSAs), and propofol and remifentanil effect-site concentration (Ce) at different time points. A two way ANOVA with post hoc analysis was applied to analyze the differences and interactions of groups and time points.

RESULTS

In both groups, DSA monitoring revealed burst suppression and α dropout immediately after the TINBs. The Ce of the propofol infusion had to be reduced within 5 min post-TINBs in both NIVATS (p < 0.001) and IVATS (p = 0.252) groups. The Ce of remifentanil infusion was significantly reduced after TINBs in both groups (p < 0.001), and was significantly lower in NIVATS (p < 0.001) without group interactions.

CONCLUSION

The surgeon-performed intraoperative multilevel TINBs allow reduced anesthetic and analgesic requirement for VATS. With lower requirement of remifentanil infusion, NIVATS presents a significantly higher risk of hypotension after TINBs. DSA is beneficial for providing real-time data that facilitate the preemptive management, especially for NIVATS.

Effect of Anesthesia Induction on Cardiac Hemodynamics in Patients Undergoing Durable Left Ventricular Assist Device Implantation: The EACH-LVAD Study

Right ventricular (RV) dysfunction is common after left ventricular assist device (LVAD) implantation leading to clinical right heart failure (RHF) associated with worsened survival and quality of life. It is likely that intraoperative events such as anesthesia induction play a role in the development or unmasking of RV dysfunction in addition to known effects from hemodynamic changes that occur after LVAD implantation. The EACH-LVAD Study is a prospective, single-center, single-arm, observational cohort study of adult patients with advanced heart failure undergoing durable LVAD implantation with standard anesthesia induction. Intraoperative RV hemodynamics via central venous pressure, mean pulmonary artery pressure, pulmonary artery pulsatility index, and vasoactive-inotropic score (a simple weighted summation of standardized drug doses) and echocardiographic parameters (RV fractional area change, RV area in diastole, RV basal diameter, septum position, RV function, tricuspid regurgitation) were measured and compared at prespecified timepoints, including postinduction. Postoperative clinical RHF was determined based on published definitions. Forty-two patients receiving a first-time LVAD were included between September 2017 and March 2019. Propofol-based induction was used in 31 patients and etomidate-based induction in eight patients. A significant increase in central venous pressure (CVP; p < 0.001), mean pulmonary artery pressure (mPAP; p < 0.001), and vasoactive inotropic score (VIS; p < 0.001) with associated decrease in pulmonary artery pulsatility index (PAPi; p < 0.001) was observed. Right ventricular function worsened throughout. Right heart failure occurred in 70% of patients. Propofol-based induction was not associated with a higher risk of RHF (relative risk [RR], 1.01 [95% confidence interval {CI}, 0.64-1.61]). The EACH-LVAD study demonstrates an effect of anesthesia induction on worsened RV hemodynamics and echocardiographic changes which may have an effect on the development of RHF.

Comparison of Procedural Sedation With Propofol and Dexmedetomidine During Transcatheter Aortic Valve Replacement Using the Transfemoral Approach

OBJECTIVES

Although procedural sedation is an established method of anesthesia for transcatheter aortic valve replacement (TAVR), reliable evidence to guide the choice of a suitable sedative agent remains scarce. Accordingly, this trial aimed to compare the effect of procedural sedation with dexmedetomidine versus propofol on postoperative neurocognitive and related clinical outcomes in patients undergoing TAVR.

DESIGN

Prospective, randomized, double-blind clinical trial.

SETTING

The study was conducted at the University Medical Centre Ljubljana, Slovenia.

PARTICIPANTS

The study enrolled 78 patients who underwent TAVR under procedural sedation between January 2019 and June 2021. Seventy-one patients randomized into the propofol group (n = 34) and dexmedetomidine group (n = 37) were included in the final analysis.

INTERVENTIONS

Patients in the propofol group received sedation with propofol (continuous intravenous infusion of 0.5-2.5 mg/kg/h), whereas patients in the dexmedetomidine group received sedation with dexmedetomidine (loading dose of 0.5 µg/kg over 10 minutes followed by continuous intravenous infusion of 0.2-1.0 µg/kg/h).

MEASUREMENTS AND MAIN RESULTS

Minimental state examination (MMSE) was performed before and 48 hours after TAVR. There was no statistically significant difference in MMSE scores between groups before TAVR (p = 0.253), but the MMSE after the procedure revealed a significantly lower incidence of delayed neurocognitive recovery (p = 0.005) and thus better cognitive outcomes in the dexmedetomidine group (p = 0.022).

CONCLUSIONS

Compared with propofol, procedural sedation with dexmedetomidine in TAVR was associated with a significantly lower incidence of delayed neurocognitive recovery.

The art of chasing numbers in titration of anaesthetic dose

There is no difference in between-patient variability of concentrations when comparing propofol and sevoflurane titrated to a bispectral index of 40-60. There is about a 300% variation in hypnotic concentration between the bottom 5% and top 5% of the population. Anaesthesia titration cannot be based solely on measured or estimated drug concentrations.

Nasal continuous positive pressure versus simple face mask oxygenation for adult obese and obstructive sleep apnea patients undergoing colonoscopy under propofol-based general anesthesia without tracheal intubation: A randomized controlled trial

STUDY OBJECTIVE

To determine if a nasal positive airway pressure (nasal CPAP) mask would decrease the number of hypoxemic events in obese and obstructive sleep apnea patients undergoing colonoscopy.

DESIGN

Single-center prospective randomized controlled trial.

SETTING

Tertiary academic center.

PATIENTS

We enrolled 109 patients with diagnosis of obesity and/or obstructive sleep apnea scheduled to undergo colonoscopy under propofol general anesthesia without planned tracheal intubation.

INTERVENTION

Patients were randomly allocated (1:1 ratio) to receive supplementary oxygen at a flow of 10 L/min, either through a nasal CPAP or a simple facemask.

MEASUREMENTS

The primary endpoint was the difference in the mean percentage of time spent with oxygen saturation below 90% between the two groups. Secondary outcomes included the need for airway maneuvers/interventions, average SpO2 during the case, duration and severity of oxygen desaturation, incidence and duration of procedural interruptions, and satisfaction and tolerance scores.

MAIN RESULTS

54 were allocated to the simple face mask and 55 to the nasal CPAP mask arms, respectively. A total of 6 patients experienced a hypoxemic event. Among these patients, the difference in the percentage of time spent with oxygen saturation below 90% was not clinically relevant (p = 1.0). However, patients in the nasal CPAP group required less chin lift (20% vs. 42.6%; p = 0.01) and oral cannula insertion (12.7% vs.29.6%; p = 0.03). The percentage of patients with at least one airway maneuver was higher in the simple face mask arm (68.5% vs. 41.8%; p = 0.005). Patient tolerance to device score was lower in the nasal CPAP group (8.85 vs. 9.56; p = 0.003).

CONCLUSIONS

A nasal CPAP did not prevent hypoxemia and should not be used routinely for colonoscopy in obese or OSA patients if a simple face mask is an alternative therapy. However, potential advantages of its use include fewer airway maneuvers or interventions, which may be desirable in certain clinical settings.

TRIAL REGISTRATION

Clinicaltrials.gov, identifier: NCT05175573.

Drug-drug interaction study of ciprofol and sodium divalproex: Pharmacokinetics, pharmacodynamics, and safety in healthy Chinese subjects

Ciprofol (also known as HSK3486) is a promising intravenous anesthetic candidate derived from propofol and independently developed by Haisco Pharmaceutical Group Co., Ltd. (Chengdu, China). Compared with propofol, ciprofol has the potential to reduce the dose required and the associated risks. Ciprofol is extensively metabolized in vivo, and its interaction with other concurrently administered drugs during clinical application is worthy of attention. Therefore, an open-label, two-stage sequential study was performed in healthy subjects who received either a single administration of ciprofol injection or ciprofol injection after oral administration of sodium divalproex. The aim of the study was to evaluate the effects of sodium divalproex on ciprofol with respect to pharmacokinetics, pharmacodynamics, and safety, thus providing a basis for the rational clinical use of ciprofol and sodium divalproex.

Efficacy and Safety of Ciprofol Sedation in ICU Patients Undergoing Mechanical Ventilation: A Multicenter, Single-Blind, Randomized, Noninferiority Trial

OBJECTIVES

To determine the effectiveness and safety of ciprofol for sedating patients in ICUs who required mechanical ventilation (MV).

DESIGN

A multicenter, single-blind, randomized, noninferiority trial.

SETTING

Twenty-one centers across China from December 2020 to June 2021.

PATIENTS

A total of 135 ICU patients 18 to 80 years old with endotracheal intubation and undergoing MV, who were expected to require sedation for 6-24 hours.

INTERVENTIONS

One hundred thirty-five ICU patients were randomly allocated into ciprofol ( n = 90) and propofol ( n = 45) groups in a 2:1 ratio. Ciprofol or propofol were IV infused at loading doses of 0.1 mg/kg or 0.5 mg/kg, respectively, over 4 minutes ± 30 seconds depending on the physical condition of each patient. Ciprofol or propofol were then immediately administered at an initial maintenance dose of 0.3 mg/kg/hr or 1.5 mg/kg/hr, to achieve the target sedation range of Richmond Agitation-Sedation Scale (+1 to -2). Besides, continuous IV remifentanil analgesia was administered (loading dose: 0.5-1 μg/kg, maintenance dose: 0.02-0.15 μg/kg/min).

MEASUREMENTS AND MAIN RESULTS

Of the 135 patients enrolled, 129 completed the study. The primary endpoint-sedation success rates of ciprofol and propofol groups were 97.7% versus 97.8% in the full analysis set (FAS) and were both 100% in per-protocol set (PPS). The noninferiority margin was set as 8% and confirmed with a lower limit of two-sided 95% CI for the inter-group difference of -5.98% and -4.32% in the FAS and PPS groups. Patients who received ciprofol had a longer recovery time ( p = 0.003), but there were no differences in the remaining secondary endpoints (all p > 0.05). The occurrence rates of treatment-emergent adverse events (TEAEs) or drug-related TEAEs were not significantly different between the groups (all p > 0.05).

CONCLUSIONS

Ciprofol was well tolerated, with a noninferior sedation profile to propofol in Chinese ICU patients undergoing MV for a period of 6-24 hours.

Performance of the SEDLine Monitor: Age Dependency and Time Delay

BACKGROUND

Devices monitoring the hypnotic component of general anesthesia can help to guide anesthetic management. The main purposes of these devices are the titration of anesthesia dose. While anesthesia at low doses can result in awareness with intraoperative memory formation, excessive administration of anesthetics may be associated with an increased risk of postoperative neurocognitive disorder. We have previously shown for various indices that they are significantly influenced by the patient's age and that the monitors have a significant time delay. Here, we evaluated the influence of patient's age and time delay on the patient state index (PSI) of the SEDLine monitor.

METHODS

To analyze the influence of the patient's age, we replayed 2 minutes of electroencephalography (EEG) of 141 patients (19-88 years, ASA I-IV) undergoing general anesthesia maintained with desflurane, sevoflurane, or propofol to the SEDLine monitor. We extracted the PSI as well as the spectral edge frequency (SEF) and performed a linear regression analysis. For evaluation of the time delay, we replayed 5 minutes of EEG of stable episodes of adequate anesthesia (PSI between 25 and 50) or light sedation/wake (PSI >70) in different orders to the SEDLine to simulate sudden changes between the states. Time delays were defined as the required time span of the monitor to reach the stable target index.

RESULTS

PSI and SEF increased significantly with the patient's age. These findings did not depend on the administered anesthetic. The evaluation of the correlation between SEF and PSI showed a strong correlation with Spearman's correlation coefficient of ρ = 0.86 (0.82; 0.89). The time delays depended on the type of transition. We found a median time delay of 54 (Min: 46; Max: 61) seconds for the important transition between adequate anesthesia and awake and 55 (Min: 50; Max: 67) seconds in the other direction.

CONCLUSIONS

With our analyses, we show that the indices presented on the SEDLine display, the PSI and the SEF, increase with age for patients under general anesthesia. Additionally, a delay of the PSI to react to sudden neurophysiologic changes due to dose of the maintenance anesthetic is of a time course that is clinically significant. These factors should be considered when navigating anesthesia relying on only the proprietary index for the SEDLine monitor.

Clinical validation of an adapted Eleveld Model for high-dose propofol treatments for depression

Repeated administration of high doses of propofol to patients with treatment-resistant depression (TRD) has been shown to produce antidepressant effects in small clinical trials. These effects can be elicited when the patient's EEG burst-suppression ratio (BSR) is maintained at 70-90% for 15 min in repeated treatments. This deep anesthesia domain lies beyond the range of current propofol pharmacokinetic/pharmacodynamic (PK/PD) models. In this study, we adapt the Eleveld model for use at deep anesthesia levels with a BSR endpoint, with the goal of aiding the estimation of the dosage of propofol needed to achieve 70-90% BSR for 15 min. We test the ability of the adapted model to predict BSR for these treatments. Twenty participants underwent 6-9 treatments of high doses of propofol (5-9 of which were included in this analysis) for a total of 115 treatments. To adapt the Eleveld model for this endpoint, we optimized the model parameters Ke0, γ and Ce50. These parameters were then used in the adapted model to estimate second-by-second BSR for each treatment. Estimated BSR was compared with observed BSR for each treatment of each participant. Median absolute performance error (MdAPE) between the estimated and observed BSR (25th-75th percentile) was 6.63 (3.79-12.96) % points and 8.51 (4.32-16.74) % between the estimated and observed treatment duration. This predictive performance is statistically significantly better at predicting BSR compared with the standard Eleveld model at deep anesthesia levels. Our adapted Eleveld model provides a useful tool to aid dosing propofol for high-dose anesthetic treatments for depression.

Variability of predicted propofol concentrations and measured sevoflurane concentrations during general anaesthesia: a single-centre retrospective cohort study

BACKGROUND

Variability is high in predicted propofol concentrations during clinical anaesthesia titrated by target-controlled infusion (TCI) to maintain a processed EEG parameter (bispectral index [BIS]) within a specified range. We have shown that the potential for improving the pharmacokinetic model is minimal. The drug titration paradox revealed that titration challenges the classical relationship between drug dose and effect in both individuals and the population. We hypothesised that dynamic factors during surgery beyond the static genetic, epigenetic, and other factors such as age, height, and weight affect the necessary dose. We compared the variability of measured end-tidal sevoflurane concentrations with predicted effect-site propofol concentrations when titrated to a BIS range of 40-60, with the hypothesis that the variability in measured sevoflurane concentrations would not be less than the variability in estimated propofol concentrations.

METHODS

Clinical data from 2280 surgical procedures >1 h in duration were included in the analysis. Anaesthesia with sevoflurane or propofol was based on an institutional protocol. The titration performance for both drugs was assessed by comparing BIS values 30 min after skin incision. The variability of the required concentrations at the same time point was calculated and compared.

RESULTS

The achieved 30-min post-incision BIS ranges were not significantly different for sevoflurane or propofol TCI (30 [99% CI: 28-33] and 31 [99% CI: 27-36], respectively). The variability of sevoflurane concentrations was not significantly different from measured predicted propofol concentrations during BIS-guided anaesthesia (normalized concentration range of 0.89 [99% CI: 0.78-0.99] and 0.93 [99% CI 0.87-1.02).

CONCLUSIONS

Improvements in prediction accuracy of pharmacokinetic models beyond that of those already in clinical use are unlikely to reduce variability in target anaesthetic concentrations across patients in clinical practice.

Total intravenous anesthesia for geriatric hip fracture with severe systemic disease

PURPOSE

Our study aimed to determine the impact of a novel technique of anesthesia administration on the clinical outcomes and complications in geriatric patients with severe systemic disease undergoing hip surgery.

METHODS

We retrospectively identified patients aged > 65 years with severe systemic disease that was a constant of life [American Society of Anesthesiologists (ASA) IV] who underwent surgery for hip fracture between January 2018 and January 2020. The patients were divided into two groups: Group I [fascia iliaca compartment block plus propofol-based total intravenous anesthesia (FICB + TIVA)] and Group II [general anesthesia (GA)]. The primary outcomes were 30-day and 1-year mortality. The secondary outcomes included length of hospital stay, length of intensive care unit (ICU) stay, postoperative morbidity, Visual Analog Scale score, and consumption of analgesics.

RESULTS

There was no significant difference in the 30-day mortality (5 vs. 3.8%, p = 0.85) and 1-year mortality (15 vs. 12%, p = 0.73) between the groups. Group I had significantly lower ICU requirements (p = 0.01) and shorter lengths of ICU stay (p < 0.001) and hospital stay (p < 0.001). Moreover, a smaller proportion of patients in Group I required postoperative morphine or oral opiates.

CONCLUSION

Geriatric patients who underwent hip surgery under FICB + TIVA required fewer ICU admissions, shorter lengths of ICU and hospital stay, and had lesser postoperative opioid consumption than those who were under GA. Hence, we recommend the novel FICB + TIVA technique for hip fracture surgery in geriatric patients with poor general health status and high surgical risks (ASA IV).

Paralysis Versus Non-Paralysis Anesthesia for Operative Laryngoscopy: A Randomized Controlled Trial

OBJECTIVE

To compare outcomes between two standard-of-care anesthesia regimens for operative laryngoscopy: general anesthesia with a neuromuscular blocking agent (NMBA) versus remifentanil and propofol (non-NMBA).

METHODS

This was a prospective, single-blinded, randomized controlled trial at a tertiary care center. Patients were randomized to either anesthesia using rocuronium (NMBA) or with remifentanil/propofol infusion alone (non-NMBA). Intraoperative impressions, anesthesia data, and post-operative patient surveys were collected.

RESULTS

Sixty-one patients who underwent suspension laryngoscopy from 2020 to 2022 were included (25 female, 36 male, ranging 20-81 years). Thirty patients were enrolled in the NMBA arm and 31 patients in the non-NMBA arm. Heart rate and mean arterial pressure were higher in the NMBA (p < 0.01). Patients in the non-NMBA group were more likely to require vasopressors (p = 0.04, RR = 3.08 [0.86-11.05]). Surgeons were more frequently satisfied with conditions in the NMBA group (86.7%) compared to the non-NMBA group (58.1%, p < 0.01). Procedures were more likely to be paused due to movement in the non-NMBA group (45.1%) compared to the NMBA group (16.6%, p < 0.03, RR = 2.26 [1.02-4.99]). Patients in the non-NMBA group were more likely to endorse myalgia the week after surgery (44%) compared to the NMBA group (8.3%, p < 0.01) and reported higher average pain levels on a 0-10 pain scale (3.7) compared to the paralysis group (2.0).

CONCLUSIONS

Anesthesia with rocuronium was associated with better intraoperative conditions and postoperative pain compared to anesthesia with remifentanil/propofol. Remifentanil/propofol were associated with lower blood pressure and suppression of laryngoscopy-associated tachycardia.

LEVEL OF EVIDENCE

2 Laryngoscope, 133:2654-2664, 2023.

Remimazolam vs Etomidate: Haemodynamic Effects in Hypertensive Elderly Patients Undergoing Non-Cardiac Surgery

Background

Remimazolam tosilate (RT) is a novel ultrashort-acting γ-aminobutyric acid subtype A (GABAA) agonist, with several advantages including rapid induction and recovery, stable haemodynamics, and mild respiratory inhibition. However, studies have not been conducted to explore the haemodynamic effects of RT in elderly hypertensive subjects undergoing non-cardiac surgery. Therefore, we sought to compare the effects of anaesthesia induction using different doses of RT and etomidate on the haemodynamics of this group of patients.

Methods

Patients were recruited into this single-center, prospective, randomized, double-blind trial from October 2022 to June 2023. A total of 150 hypertensive elderly undergoing non-cardiac surgery were randomly assigned into 0.2 mg/kg RT group (Group RL), 0.3 mg/kg RT group (Group RH) and 0.3 mg/kg etomidate group (Group E). The primary outcome of the study was haemodynamic changes (mean arterial pressure fluctuation value -∆MAP and heart rate fluctuation value -∆HR) observed during anaesthesia induction. Secondary outcomes included incidence of adverse cardiovascular events and adverse drug reactions (injection pain and myoclonus), cumulative doses of vasoactive drugs and vital signs at different time points.

Results

Patients in Group E and Group RL had significantly lower haemodynamic fluctuations (∆MAP), lower incidence of hypotension and cumulative dose of ephedrine than subjects in Group RH. Patients in groups RL and RH had significantly lower incidence of injection pain and myoclonus compared with patients in group E. The results showed no statistically significant differences in ∆HR, hypertension, bradycardia, tachycardia, and time to loss of eye-opening reflex and start of intubation, and vital signs at different time points among the three groups.

Conclusion

Use of low-dose RT (0.2 mg/kg) for induction of non-cardiac surgical anaesthesia in elderly hypertensive patients is more effective in maintaining haemodynamic stability and has fewer adverse effects compared with etomidate.

Efficacy and Safety of Different Doses of Remimazolam Tosilate Applied in Upper Gastrointestinal Endoscopy: A Prospective Randomized Controlled Double-Blind Trial

Background

Remimazolam is a novel benzodiazepine narcotic. When used for gastrointestinal endoscopy or bronchoscopy, it provides adequate sedation and rapid recovery. However, studies on the optimal initial loading dose of remimazolam remain inadequate. Therefore, we conducted a randomized controlled clinical trial to investigate the efficacy and safety of different doses of remimazolam applied in upper gastrointestinal endoscopy.

Methods

A total of 218 patients scheduled for upper gastrointestinal endoscopy were included in our trial and divided into experimental and control groups: the experimental groups were the remimazolam groups (R1 of 0.2 mg/kg, R2 of 0.3 mg/kg, and R3 of 0.4 mg/kg), and the control group was the propofol group. Following a single injection of trial drugs during the induction period, operational requirements were evaluated based on MOAA/S scores. When the sedation was successfully achieved, safety was evaluated based on the incidence of various intraoperative and postoperative adverse events.

Results

The success rates of intraoperative sedation were 82% in group R1, 98% in group R2, 96% in group R3, and 100% in group P. The incidence of hypotension was lower in the remimazolam groups than in the propofol group (16%), 4% in group R1, 6% in group R2, and 6% in group R3. The incidence of postoperative vertigo was significantly higher, and sedation recovery time was prolonged in high-concentration remimazolam group.

Conclusion

Satisfactory efficacy can be obtained with higher concentrations of remimazolam tosilate in patients undergoing upper gastrointestinal endoscopy with ASA grade I or II. However, as the dose is progressively increased, the incidence of adverse reactions by remimazolam tosilate are also significantly increased, such as vertigo and prolonged sedation recovery time.

Trial Registration

The trial was registered prior to enrollment at the Chinese Clinical Trial Registry (ChiCTR 2000032067).

Effect of esketamine on inflammatory factors in opioid-free anesthesia based on quadratus lumborum block: A randomized trial

BACKGROUND

As strong analgesics, opioids provide the analgesic component of general anesthesia, but they have bidirectional effects on the immune system, promoting the production of pro-inflammatory factors. The idea of opioid-free anesthesia is to replace the analgesic effect of opioids in the treatment of acute pain with comparably effective drugs that do not affect the immune system and thereby decrease the production of inflammatory factors. Therefore, this study aims to observe the effect of opioid-free esketamine anesthesia based on quadratus lumborum block on inflammatory factors in patients undergoing lower abdominal or pelvic surgery.

METHODS

A total of 122 patients who underwent lower abdominal or pelvic surgery in our hospital from March 2021 to June 2022 were selected and divided into the esketamine (E) group (n = 62) and control (C) group (n = 60) according to the random number table method. According to the surgical field, the 2 groups underwent unilateral/bilateral quadratus lumborum block in the supine position under ultrasound guidance. In addition, both groups received a target controlled infusion of propofol 3 to 3.5 μg/mL and intravenous rocuronium 0.8 mg/kg. Group E was given opioid-free anesthesia, group C was given opioid-based anesthesia. A 3 to 5 laryngeal mask was inserted according to body weight, and rocuronium 0.5 mg/kg was added intermittently. The levels of interleukin-6 (IL-6), interleukin-8 (IL-8), C-reactive protein (CRP), procalcitonin, tumor necrosis factor-α (TNF-α), numeric rating scales, dosage of propofol, dexmedetomidine and rocuronium, as well as the numeric rating scales score and analgesic complications were monitored in the 2 groups.

RESULTS

There was no significant differences in general outcomes between the 2 groups (P > .05). The blood pressure in group E was higher than in group C at T1 (P < .05). The levels of IL-6, TNF-α, CRP and IL-8 in group E were significantly lower than in group C at T1, T2, T3, and T4 (P < .05). The levels of IL-6, TNF-α, procalcitonin, CRP and IL-8 in the 2 groups at T1, T2, T3, and T4 were significantly higher than at T0 (P < .05).

CONCLUSION

Opioid-free esketamine anesthesia based on quadratus lumborum block achieved perfect postoperative analgesia with little effect on inflammatory factors in patients undergoing lower abdominal or pelvic surgery.

Effects of remimazolam combined with sufentanil on hemodynamics during anesthetic induction in elderly patients with mild hypertension undergoing orthopedic surgery of the lower limbs: a randomized controlled trial

BACKGROUND

This randomized controlled trial was performed to observe the effect of remimazolam with sufentanil on hemodynamics during anesthetic induction in elderly patients with mild hypertension undergoing orthopedic surgery of the lower limbs.

METHODS

Sixty elderly patients were randomly assigned to undergo general anesthesia with intravenous injection of either remimazolam besylate (25 mg/vial, batch number 10T11011; Yichang Humanwell Pharmaceutical Co., Ltd., Yichang, China) at 0.2 mg/kg (Group R, n = 30) or propofol at 1.5 mg/kg (Group P, n = 30). Both injections were completed within 15 to 20 s. If the bispectral index value did not reach 40 to 60, then 0.05 mg/kg of remimazolam was added in Group P and 1 mg/kg of propofol was added in Group R. When the BIS value reached 40 to 60, sufentanil was administered at 0.3 to 0.5 µg/kg and cisatracurium was administered at 0.15 to 0.2 mg/kg in both groups. Three minutes later, tracheal intubation and controlled ventilation were performed to maintain the end-tidal carbon dioxide partial pressure at 4.5 to 5.0 kPa. The mean arterial pressure (MAP), heart rate (HR), cardiac output (CO), continuous cardiac index (CI), systemic vascular resistance (SVR), and pulse oxygen saturation were recorded before induction (T0), when the eyelash reflex disappeared (T1), immediately after endotracheal intubation (T2), 1 min after endotracheal intubation (T3), and 5 min after endotracheal intubation (T4). The disappearance time of the eyelash reflex, injection pain, hypotension, bradycardia, hiccupping, nausea and vomiting, and other adverse events were observed.

RESULTS

The MAP, HR, CO, and CI at T1, T2, T3, and T4 were significantly higher in Group R than P, while SVR was significantly lower in Group R than P (P < 0.05). In Group P, the MAP, HR, CO, and CI were significantly lower and the SVR was significantly higher at T1, T2, T3, and T4 than at T0 (P < 0.05). Adverse events occurred in 8 (20%) patients in Group R and 22 (73%) in Group P. The total incidence of adverse events was significantly lower in Group R than P (P < 0 0.001).

CONCLUSION

Remimazolam combined with sufentanil for general anesthesia induction has the advantages of small hemodynamic fluctuations, stable circulation, and few adverse reactions, making it suitable for elderly patients with mild hypertension.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2300069224, 10/03/2023).