ICU- and ventilator-free days with isoflurane or propofol as a primary sedative - A post- hoc analysis of a randomized controlled trial

PURPOSE

To compare ICU-free (ICU-FD) and ventilator-free days (VFD) in the 30 days after randomization in patients that received isoflurane or propofol without receiving the other sedative.

MATERIALS AND METHODS

A recent randomized controlled trial (RCT) compared inhaled isoflurane via the Sedaconda® anaesthetic conserving device (ACD) with intravenous propofol for up to 54 h (Meiser et al. 2021). After end of study treatment, continued sedation was locally determined. Patients were eligible for this post-hoc analysis only if they had available 30-day follow-up data and never converted to the other drug in the 30 days from randomization. Data on ventilator use, ICU stay, concomitant sedative use, renal replacement therapy (RRT) and mortality were collected.

RESULTS

Sixty-nine of 150 patients randomized to isoflurane and 109 of 151 patients randomized to propofol were eligible. After adjusting for potential confounders, the isoflurane group had more ICU-FD than the propofol group (17.3 vs 13.8 days, p = 0.028). VFD for the isoflurane and propofol groups were 19.8 and 18.5 respectively (p = 0.454). Other sedatives were used more frequently (p < 0.0001) and RRT started in a greater proportion of patients in the propofol group (p = 0.011).

CONCLUSIONS

Isoflurane via the ACD was not associated with more VFD but with more ICU-FD and less concomitant sedative use.

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.