Comparison of the Safety and Efficacy of Remimazolam Besylate versus Dexmedetomidine for Patients Undergoing Fiberoptic Bronchoscopy: A Prospective, Randomized Controlled Trial.

Objective: Remimazolam besylate is a novel ultra-short-acting benzodiazepine that is rapidly hydrolyzed to zolpidem propionic acid by tissue lipases. We designed this study to compare the safety and efficacy of remimazolam besylate alfentanil versus dexmedetomidine-alfentanil for fiberoptic bronchoscopy (FB). Methods: One hundred and twenty patients undergoing FB into this prospective randomized controlled trial were divided into two groups. The anesthesia induction consisted of 6 mg/kg/h of remimazolam besylate in the RA group and 0.5 µg/kg of dexmedetomidine in the DA group. 1-2 mg/kg/h of remimazolam besylate or 0.2-0.7 µg/kg/h of dexmedetomidine were administered to maintain during FB. The lowest oxygen saturation, success rate of FB, hemodynamics, time metrics, bronchoscopy feasibility, drug dose requirements, patient and bronchoscopist satisfaction scores, occurrence of intraoperative awareness, number of patients willing to repeat FB with the same sedation regimen, and occurrence and severity of adverse events. Results: The lowest oxygen saturation during the FB was significantly higher in the RA group (P = 0.001). Compared with the variables in the DA group, peripheral oxygen saturation, systolic blood pressure, and diastolic blood pressure were significantly lower at T2 and T3 in the RA group (P < 0.05). Heart rates were significantly higher from T2 to T4 in the DA group (P < 0.05). More patients experienced bradycardia in the DA group (P = 0.041). Compared with time metrics in the DA group, the induction time, fully-alert time, and recovery room-leaving time were all significantly shorter in the RA group (P < 0.05). The bronchoscopy feasibility scores in the RA group were significantly lower at T2, whereas they were lower at T3 in the DA group (P < 0.05). Conclusion: Remimazolam besylate is superior to dexmedetomidine when combined with alfentanil during FB, promoting faster patients' recovery, better operative conditions and respiratory stability with similar rates of occurrence and severity of adverse events.

Low-Dose Alfentanil Inhibits Sufentanil-Induced Cough During Anesthesia Induction: A Prospective, Randomized, Double-Blind Study.

Background: Cough is one of the most common complications following intravenous administration of sufentanil during anesthesia induction. The study aimed to investigate the protective effect of alfentanil, afentanyl derivative with short onset time and short duration, in reducing sufentanil-induced cough. Patients and methods: Eighty patients that scheduled for thyroid surgery under general anesthesia were randomly divided into the alfentanil group and normal saline group, with 40 cases per group. Patients in the alfentanil group received intravenous administration of 2 µg/kg alfentanil prior to sufentanil injection during general anesthesia induction, while the same dose of normal saline was administered in the normal saline group. The outcomes measures included the incidence and severity of cough and common side effects of opioids following the administration of sufentanil during the induction of general anesthesia, intraoperative hemodynamics parameters and major adverse events during anesthesia recovery period. Results: The incidence of cough within one minute after the injection of sufentanil during anesthesia induction was 40% in the normal saline group, and the pretreatment of alfentanil significantly reduced the incidence of sufentanil-induced cough to 5% (p < 0.05). Correspondingly, the patients in the alfentanil group had decreased severity of sufentanil-induced cough compared with the normal saline group (p < 0.05). No significant differences in the incidences of common side effects of opioids (dizziness, nausea and vomiting, chest tightness and respiratory depression) within one minute after sufentanil injection were found (p > 0.05). Furthermore, there were no significant differences between the two groups in intraoperative hemodynamic parameters, extubation time, or the incidences of emergence agitation, respiratory depression, delayed recovery from anesthesia and postoperative nausea and vomiting during Postanesthesia Care Unit stay (p > 0.05). Conclusion: Pretreatment with low-dose alfentanil (2 µg/kg) effectively and safely reduced both the incidence and severity of sufentanil-induced cough during anesthesia induction. Clinical Trial Registration Number: Chinese Clinical Trial Registry (identifier: ChiCTR2300069286).

Determination of ED50 and ED95 of remimazolam besylate combined with alfentanil for adult gastroscopy: a prospective dose-finding study.

BACKGROUND: To explore the median effective dose (ED50) and 95% effective dose (ED95) of remimazolam besylate combined with alfentanil for adult gastroscopy. METHODS: This prospective studyenrolled 31 patients scheduled to painless gastroscopy at Anhui No. 2 Provincial People's Hospital between April and May, 2022. 5 µg.kg-1 of alfentanil hydrochloride was used for pre-analgesia. The initial single loading dose of remimazolam besylate was 0.12 mg.kg-1, increased or reduced by 0.01 mg.kg-1 for the next patient with modified Dixon sequential method. The modified Observer's Assessment of Alertness/Sedation Scale (MOAA/S) was used to assess sedation. RESULTS: Combined with alfentanil, the ED50 of remimazolam besylate was 0.147 mg.kg-1 (95% CI: 0.138-0.160 mg.kg-1) and ED95 0.171 mg.kg-1 (95% CI: 0.159-0.245 mg.kg-1). The induction time after injection of remimazolam besylate was 70 ± 25 s, with the anesthesia recovery time and the observation time in resuscitation room 5.13 ± 2.13 min and 2.32 ± 1.6 min, respectively. Twenty nine patients' vital signs were within acceptable limits during gastroscopy. CONCLUSIONS: The ED50 of remimazolam besylate combined with alfentanil for painless gastroscopy was 0.147 mg.kg-1, and the ED95 was 0.171 mg.kg-1.

The 90% effective dose (ED90) of remimazolam for inhibiting responses to the insertion of a duodenoscope during ERCP.

BACKGROUND: Compared to midazolam, remimazolam has a faster onset and offset of hypnotic effect, as well as cardiorespiratory stability, this study aims to determine the 90% effective dose (ED90) of remimazolam to inhibit responses to insertion of a duodenoscope during endoscopic retrograde cholangiopancreatography (ERCP). METHODS: A dose-response study was carried out undergoing ERCP who received remimazolam-alfentanil anesthesia using 10 µg/kg of alfentanil between September 2021 and November 2021. The initial dose of remimazolam was 0.2 mg/kg. The dose was then decided based on the responses of earlier patients by exploiting the sequential ascend and descend according to a 9: 1 biased coin design. Upon failure, the dose of remimazolam was increased by 0.025 mg/kg in the next patient. When the insertion was successful, the succeeding patient was randomized to an identical dose or a dose that was lower by 0.025 mg/kg.The ED90 of remimazolam for inhibiting responses to the insertion of a duodenoscope during ERCP was calculated. Adverse events and complications of remimazolam were recorded. RESULTS: A total of 55 elderly patients (age > 65) were included in the study. 45 successfully anesthetized patients, and 10 unsuccessfully. The ED90 of remimazolam was 0.300 mg/kg (95% CI = 0.287-0.320). ED95 was 0.315 (95% CI = 0.312-0.323) and ED99 was 0.323 (95% CI = 0.323-0.325). Among the patients, 9 patients developed hypotension, 2 patients developed bradycardia and 1 patient developed tachycardia, and hypoxia occurred in 2 patients. CONCLUSIONS: A loading dose of 0.300 mg / kg of remimazolam for elderly patients undergoing ERCP can safely, effectively, and quickly induce patients to fall asleep and inhibit responses to the insertion of a duodenoscope. TRIAL REGISTRATION: The study protocol was registered at the website ClinicalTrials.gov on 22/09/2021(NCT05053763).

Safety and efficacy of a low-dose combination of midazolam, alfentanil, and propofol for deep sedation of elderly patients undergoing ERCP.

BACKGROUND: Proper sedation of patients, particularly elderly individuals, who are more susceptible to sedation-related complications, is of significant importance in endoscopic retrograde cholangiopancreatography (ERCP). This study aims to assess the safety and efficacy of a low-dose combination of midazolam, alfentanil, and propofol for deep sedation in elderly patients undergoing ERCP, compared to a group of middle-aged patients. METHODS: The medical records of 610 patients with common bile duct stones who underwent elective ERCP under deep sedation with a three-drug regimen, including midazolam, alfentanil, and propofol at Shandong Provincial Third Hospital from January 2023 to September 2023 were retrospectively reviewed in this study. Patients were categorized into three groups: middle-aged (50-64 years, n = 202), elderly (65-79 years, n = 216), and very elderly (≥ 80 years, n = 192). Intraoperative vital signs and complications were compared among these groups. RESULTS: The three groups showed no significant difference in terms of intraoperative variation of systolic blood pressure (P = 0.291), diastolic blood pressure (P = 0.737), heart rate (P = 0.107), peripheral oxygen saturation (P = 0.188), bispectral index (P = 0.158), and the occurrence of sedation-related adverse events including hypotension (P = 0.170) and hypoxemia (P = 0.423). CONCLUSION: The results suggest that a low-dose three-drug regimen consisting of midazolam, alfentanil, and propofol seems safe and effective for deep sedation of elderly and very elderly patients undergoing ERCP procedures. However, further studies are required to verify these findings and clarify the benefits and risks of this method.

The 90% effective concentration of alfentanil combined with 0.075% ropivacaine for epidural labor analgesia: a single-center, prospective, double-blind sequential allocation biased-coin design.

PURPOSE: More literature studies have reported that alfentanil is safe and effective for labor analgesia. However, there is no unified consensus on the optimal dosage of alfentanil used for epidural analgesia. This study explored the concentration at 90% of minimum effective concentration (EC90) of alfentanil combined with 0.075% ropivacaine in patients undergoing epidural labor analgesia to infer reasonable drug compatibility and provide guidance for clinical practice. METHODS: In this prospective, single-center, double-blind study, a total of 45 singleton term primiparas with vaginal delivery who volunteered for epidural labor analgesia were recruited. The first maternal was administered with 3 µg/mL alfentanil combined with 0.075% ropivacaine with the infusion of 10 mL of the mixture every 50 min at a background dose of 3 mL/h. In the absence of PCEA, a total of 15 mL of the mixture is injected per hour. The subsequent alfentanil concentration was determined on the block efficacy of the previous case, using an up-down sequential allocation with a bias-coin design. 30 min after epidural labor analgesia, the block of patient failed with visual analog score (VAS) > 3, the alfentanil concentration was increased in a 0.5 µg/mL gradient for the next patient, while the block was successful with VAS ≤ 3, the alfentanil concentration was remained or decreased in a gradient according to a randomized response list for the next patient. EC90 and 95% confidence interval were calculated by linear interpolation and prediction model with R statistical software. RESULTS: In this study, the estimated EC90 of alfentanil was 3.85 µg/mL (95% confidence interval, 3.64-4.28 µg/mL). CONCLUSION: When combined with ropivacaine 0.075%, the EC90 of alfentanil for epidural labor analgesia is 3.85 µg/mL in patients undergoing labor analgesia.

Effective doses of ciprofol combined with alfentanil in inhibiting responses to gastroscope insertion, a prospective, single-arm, single-center study.

BACKGROUND: Ciprofol is a novel intravenous sedative and anesthetic. Studies have shown that it features a rapid onset of action, a fast recovery time, slight inhibition of respiratory and cardiovascular functions, and a low incidence of adverse reactions. This study aims to explore the median effective dose (ED50) and the 95% effective dose (ED95) of ciprofol in inhibiting responses to gastroscope insertion when combined with a low dose of alfentanil, and to evaluate its safety, to provide a reference for the rational use of ciprofol in clinical practices. METHODS: We included 25 patients aged 18-64 years of either sex who underwent gastroscopy under intravenous general anesthesia, with a Body Mass Index (BMI) 18-28 kg/m2, and an American Society of Anesthesiologists (ASA) grade I or II. In this study, the dose-finding strategy of ciprofol followed a modified Dixon's up-and-down method with an initial dose of 0.30 mg/kg and an increment of 0.02 mg/kg. Ciprofol was administered after intravenous injection of 7 µg/kg of alfentanil, and 2 min later a gastroscope was inserted. When the insertion response of one participant was positive (including body movement, coughing, and eye opening), an escalation of 0.02 mg/kg would be given to the next participant; otherwise, a de-escalation of 0.02 mg/kg would be administered. The study was terminated when negative response and positive response alternated 8 times. A Probit model was used to calculate the ED50 and ED95 of ciprofol in inhibiting responses to gastroscope insertion when combined with alfentanil. Patients' recovery time, discharge time, vital signs and occurrence of adverse reactions were recorded. RESULTS: The ED50 of single-dose intravenous ciprofol injection with 7 µg/kg of alfentanil in inhibiting gastroscope insertion responses was 0.217 mg/kg, and the ED95 was 0.247 mg/kg. Patients' recovery time and discharge time were 11.04 ± 1.49 min and 9.64 ± 2.38 min, respectively. The overall incidence of adverse reactions was 12%. CONCLUSION: The ED50 of ciprofol combined with 7 µg/kg of alfentanil in inhibiting gastroscope insertion responses was 0.217 mg/kg, and the ED95 was 0.247 mg/kg. Ciprofol showed a low incidence of anesthesia-related adverse events. TRIAL REGISTRATION: http://www.chictr.org.cn (ChiCTR2200061727).

Comparison of ciprofol-alfentanil and propofol-alfentanil sedation during bidirectional endoscopy: A prospective, double-blind, randomised, controlled trial.

BACKGROUND: Although propofol is widely used for gastrointestinal endoscopic sedation, cardiopulmonary adverse events remain common. Ciprofol is a new intravenous anaesthetic agent demonstrating respiratory and hemodynamic stability. AIMS: This study aimed to clarify the benefits of ciprofol combined with alfentanil in bidirectional endoscopy (esophagogastroduodenoscopy followed by colonoscopy) to reduce adverse events and improve post-endoscopic recovery. METHODS: A total of 185 patients scheduled to undergo bidirectional endoscopy were randomly divided into two groups: ciprofol combined with alfentanil or propofol combined with alfentanil. All patients received 7 µg/kg alfentanil intravenously before the study drugs were administered. The propofol group received a bolus of 1.2 mg/kg (0.12 ml/kg) propofol intravenously, whereas the ciprofol group received a bolus of 0.3 mg/kg (0.12 ml/kg) ciprofol intravenously. The primary outcome was the proportion of patients with cardiopulmonary adverse events (i.e., any one of the airway obstruction, apnoea, hypotension, hypertension, bradycardia, tachycardia or arrhythmias). RESULTS: Compared with propofol, ciprofol reduced cardiopulmonary adverse events by 43.51 % (34.4% vs. 60.9 %, P <0.001), mitigated respiratory adverse events by 54.74 % (17.2% vs. 38.0 %, P = 0.002) overall and by 59.05 % (12.9% vs. 31.5 %, P = 0.002) during the induction period. CONCLUSIONS: Ciprofol can significantly decrease respiratory depression events and provides a better sedative efficacy than propofol with higher recovery quality and satisfaction.

Effects of alfentanil on myocardial fibrosis in rats with acute myocardial infarction by regulating the SphK1/S1P signaling pathway / 中国药房

OBJECTIVE To explore the effects of alfentanil （ALF） on myocardial fibrosis in rats with acute myocardial infarction （AMI） by regulating sphingosine kinase 1 （SphK1）/sphingosine 1-phosphate （S1P） signaling pathway. METHODS Male SD rats were collected to construct AMI model by the ligation of anterior descending branch of left coronary artery. The successfully modeled rats were randomly divided into AMI model group （Model group）， ALF low-dose group （ALF-L group， 0.25 mg/kg ALF）， ALF high-dose group （ALF-H group， 0.5 mg/kg ALF）， high dose of ALF+SphK1 activator group （ALF-H+K6PC-5 group， 0.5 mg/kg ALF+1 μg/g K6PC-5）. At the same time， a sham operation group （Sham group） was set up to perform only chest opening/closing operations without ligating the anterior descending branch of left coronary artery， with 15 rats in each group. Rats in each drug group were intraperitoneally injected with the corresponding drug solution， once a day， for 4 consecutive weeks. Twelve hours after the last medication， cardiac function indicators [left ventricular systolic pressure （LVSP）， left ventricular ejection fraction （LVEF）， left ventricular systolic diameter （LVSD）， left ventricular fractional shortening （LVFS）] of rats were detected in each group； the condition of myocardial infarction， pathological changes in myocardial tissue， and degree of fibrosis were observed； serum levels of brain natriuretic peptide （BNP） and cardiac troponin Ⅰ （cTnⅠ） in rats were detected. The protein expressions of collagen Ⅰ ， collagen Ⅲ ， matrix metalloproteinase-2 （MMP-2）， SphK1 and S1P were alsodetected in the myocardial tissue of rats. RESULTS Compared with the Sham group， the arrangement of myocardial cells in the Model group was disordered， with a large number of inflammatory cells infiltrating. The levels of LVSP， LVFS and LVEF in the Model group were significantly reduced （P＜0.05）； LVSD level， myocardial infarction area， collagen volume fraction， serum levels of BNP and cTnⅠ， the protein expressions of collagen Ⅰ， collagen Ⅲ， MMP-2， SphK1 and S1P in myocardial tissue were significantly increased or enlarged （P＜0.05）. Compared with the Model group， the pathological changes and degree of fibrosis in the myocardial tissue of rats in each dose group of ALF were improved or relieved， while the quantitative indicators of rats in the ALF-H group were significantly improved and significantly better than those in ALF-L group （P＜0.05）. K6PC-5 could significantly reverse the improvement effect of high-dose ALF on the above quantitative indicators in rats （P＜0.05）. CONCLUSIONS ALF can reduce myocardial fibrosis and improve cardiac function in AMI rats， and the effect may be related to the inhibition of the SphK1/S1P signaling pathway.

Modified Dixon sequential method to determine the effective dose of alfentanil compounded with propofol for day-case hysteroscopy.

Background: Propofol combined with alfentanil is suitable for intravenous anesthesia for day-case hysteroscopy. Objective: To investigate the median effective dose (ED50) and 95% effective dose (ED95) of alfentanil compounded with propofol for day-case hysteroscopy. Design: In all, 29 patients who volunteered for painless hysteroscopy in 2022 were recruited. 1.5 mg/kg propofol was given as a sedative to all patients. The trial was conducted using the modified Dixon sequential method, with an initial dose of 10 µg/kg of alfentanil, and the subject's alfentanil dose depended on whether the prior hysteroscopy had failed, which was defined as inadequate cervical dilatation and hysteroscope placement with the patient exhibiting body movement, frowning, or a MOAA/S score >1. If the hysteroscopy failed (i.e. a positive response), the subsequent subject's alfentanil dosage was raised, and conversely (i.e. a negative response), the dose was decreased, with the adjacent dose ratio always being 1:1.2. The formal test begins with the first crossover wave and lasts until seven crossover waves materialize. Methods: The probit method was used to calculate the ED50, ED95, and corresponding 95% confidence intervals (CIs) of alfentanil compounded with propofol for hysteroscopy. Results: The ED50 and ED95 of alfentanil combined with propofol for day-case hysteroscopy were 5.701 (95% CI: 3.841-7.069) µg/kg and 8.817 (95% CI: 7.307-20.868) µg/kg, respectively. Conclusion: Alfentanil at 8.817 µg/kg in conjunction with propofol is a successful and safe approach for day-case painless hysteroscopy. Trial registration: The trial registry name: Modified sequential method to determine the half-effective dose of alfentanil compounded with propofol for ambulatory hysteroscopy. The URL of registration is https://www.chictr.org.cn/showproj.html?proj=171786, where the full trial protocol can be accessed. Registration number: ChiCTR2200061619.

Alfentanil combined with propofol is suitable for day-case hysteroscopy Why was this study done? Hysteroscopy is a procedure in which a hysteroscope is placed after the cervix is dilated to observe lesions in the uterine cavity. This study explores the effective dose of alfentanil combined with propofol for day-case (i.e., patients admitted and discharged on the same day) hysteroscopy to provide patients with comforting anesthesia (i.e., pain relief) during hysteroscopy. What did the researchers do? The research team recruited 29 patients who volunteered for painless hysteroscopy in 2022. All patients received alfentanil and propofol for intravenous anesthesia. If anesthesia was not effective, subsequent subjects increased the dose of anesthetic medication, and vice versa, the dose was decreased. According to this method, we can find the optimal dose of anesthetic drugs in hysteroscopy. What did the researchers find? The effective dose of alfentanil combined with propofol in patients undergoing painless hysteroscopy was 8.817 µg/kg. What do the findings mean? Alfentanil at 8.817 µg/kg in conjunction with propofol is a successful and safe approach for day-case painless hysteroscopy.

Remimazolam Pilot for Office-Based Dental Sedation: Adverse Events, Awareness and Outcomes.

In recent years, remimazolam has gained approval for use in adult procedural sedation in both the United Kingdom and the United States, potentially offering an alternative to conventional sedatives like propofol and midazolam for procedural sedation. However, there is a limited body of literature that systematically reviews the outcomes of a remimazolam-alfentanil combination protocol for routine office-based dental procedures. The primary objective of this pilot study was to assess the occurrence of significant adverse events associated with the use of a remimazolam-alfentanil sedation protocol for adult dental procedures. Secondary outcomes included evaluating physiological responses, sedation effectiveness, patient and clinician satisfaction and the incidence of intraprocedural awareness. Notably, no significant adverse events were reported among the 25 adult subjects who received remimazolam and alfentanil, and all dental procedures were successfully completed. Patients and clinicians expressed high levels of satisfaction, and patients did not report any distressing memories associated with the dental procedure. These findings suggest that in a limited cohort, the remimazolam-alfentanil regimen appears to be well tolerated and effective for office-based dental procedures in adult patients, with a low risk of adverse events, acceptable hemodynamic effects, rapid onset and recovery and minimal intraoperative awareness. This study provides valuable insights into the potential use of the remimazolam-alfentanil combination in dental sedation practice.

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.

A promising and highly sensitive electrochemical platform for the detection of fentanyl and alfentanil in human serum.

A novel electrochemical method has been developed, based on a covalent organic framework (COF) and reduced graphene oxide (rGO), to detect fentanyl and alfentanil. COF nanomaterials with chrysanthemum morphology obtained by solvothermal reaction contain rich active sites for electrochemical catalytic reaction, thus improving the detection performance of the designed sensor. Reduced graphene oxide improves the sensor's sensitivity due to enhanced electron transfer. Under optimized experimental conditions, the fabricated electrode presents a linear range of 0.02 to 7.26 µM for alfentanil and 0.1 to 6.54 µM for fentanyl, with detection limits of 6.7 nM and 33 nM, respectively. In addition, the sensor possesses excellent selectivity, outstanding reproducibility, and acceptable stability. The proposed sensor is feasible for the reliable monitoring of fentanyl and alfentanil in human serum samples, with acceptable reliability and high potential in real-world applications. Finally, the electrochemical characteristic fingerprint of fentanyl is investigated by studying the electrochemical behavior of alfentanil and fentanyl on the electrode surface.

Effects of single-use alfentanil versus propofol on cognitive functions after colonoscopy: A randomized controlled trial.

Purpose: Colonoscopy is often accompanied by short-term postoperative cognitive decline. We aimed to explore whether single-use alfentanil for patients undergoing elective colonoscopy could reduce cognitive impairment at discharge compared with propofol. Patients and methods: 172 adult patients undergoing elective colonoscopy were randomized to receive intravenous propofol at 2 mg/kg (group P) or alfentanil at 10 µg/kg (group A); 40 healthy volunteers were included in the blank group. Cognitive function was considered the primary outcome and was measured using five neuropsychological tests before sedation and discharge. The z-score method was used to determine cognitive dysfunction according to z-score >1.96 in two types of neuropsychological tests. Other outcomes included discharge time, vital signs, associated adverse events during colonoscopy, and the satisfaction level of patients and endoscopic physicians. Results: 164 patients (78 in group A and 86 in group P) completed the study protocol. At discharge, the incidence of cognitive dysfunction in group P was 23% and was significantly lower in the alfentanil group (2.5%), with a relative risk of 0.11 (95% confidence interval: 0.03-0.46, P < 0.001). The incidence of hypotension in group A was lower than that in group P (3.8% vs 22.1%, relative risk = 0.17 [95% confidence interval: 0.05-0.46, P = 0.001]), and the discharge time in group A was shorter than that in group P (5 [(Rutter and et al., 2016; Zhang and et al., 2013; Hirsh and et al., 2006; Zhou and et al., 2021; Singh and et al., 2008; Ko and et al., 2010; Sargin et al., 2019) 3-93-9 vs 13 [(Ekmekci and et al., 2017; Eberl and et al., 2012; Eberl and et al., 2014; N'Kaoua and et al., 2002; Chung et al., 1995; Berger and et al., 2019; Quan and et al., 2019; Deng and et al., 2021; Gualtieri and Johnson, 2006) 10-1810-18 min, P < 0.001). Conclusion: For patients undergoing colonoscopy, single-use alfentanil causes less damage to postoperative cognitive function, less risk of hypotension, and shorter discharge time than propofol.

Remimazolam-remifentanil causes less postoperative nausea and vomiting than remimazolam-alfentanil during hysteroscopy: a single-centre randomized controlled trial.

BACKGROUND: Although the operation time of hysteroscopy is short, the incidence of postoperative nausea and vomiting is high. The aim of this study was to compare the incidence of postoperative nausea and vomiting in hysteroscopy when remimazolam is combined with remifentanil or alfentanil. METHODS: We conducted a randomized, controlled, double-blind trial. Patients undergoing hysteroscopy were recruited and randomly assigned to either the remimazolam-remifentanil (Group RR) or the remimazolam-alfentanil group (Group RA). All patients in the two groups were started with an induction dose of remimazolam besylate 0.2 mg/kg and then maintained with a dosage of 1.0 mg/kg/h. After induction with remimazolam besylate, in Group RR, remifentanil was infused using a target-controlled infusion system with a target concentration of 1.5 ng/ml and titrated throughout the procedure. In Group RA, infusion of alfentanil was started with an initial bolus dose of 20 µg/kg over 30 s and then maintained at an initial rate of 0.16 µg/kg/min. The primary observation outcome was the incidence rate of postoperative nausea and vomiting. The secondary observation outcomes were the time to awakening, the length of stay in the PACU, the total remimazolam dose and adverse effects, such as low SpO2, bradycardia, hypotension and body movement. RESULTS: A total of 204 patients were successfully included in this study. The incidence of postoperative nausea and vomiting in Group RR (2/102, 2.0%) was significantly lower than that in Group RA (12/102, 11.8%) (p < 0.05). There was no significant difference in the incidence of adverse events, such as low SpO2, bradycardia, hypotension and body movement, between Groups RR and RA (p > 0.05). CONCLUSIONS: Remimazolam-remifentanil causes less postoperative nausea and vomiting than remimazolam-alfentanil in hysteroscopy. TRIAL REGISTRATION: Clinical trial registration number: ChiCTR2100044177. Full date of the first registration: 12/03/2021.

Cardiopulmonary Adverse Events of Remimazolam versus Propofol During Cervical Conization: A Randomized Controlled Trial.

Purpose: This study aimed to compare the cardiopulmonary safety of remimazolam and propofol in patients undergoing cervical conization. Methods: This was a single-blind, parallel, randomized controlled study. A total of 204 patients scheduled for day surgery of cold knife cervical conization received either remimazolam-alfentanil anesthesia (remimazolam group) or propofol-alfentanil anesthesia (propofol group). The primary outcome was the incidence of intraoperative cardiopulmonary adverse events (a composite outcome of hypotension, bradycardia and hypoxemia). The occurrence of hypotension, bradycardia, hypoxemia and the degree of body movement were secondary outcomes, as well as the moment at which consciousness was lost, the interval between the end of anesthesia and the operating room's release of the patient, and the overall dosage of alfentanil administered during the procedure. Results: The incidence of intraoperative cardiopulmonary adverse events was 45 (44.1%) in the remimazolam group and 72 (70.6%) in the propofol group (absolute risk difference [95% CI], -26.47% [-39.55% to -13.39%]; odds ratio (OR) [95% CI], 0.43 [0.28 to 0.65]; P < 0.001). The remimazolam group showed lower incidences of hypotension and hypoxemia compared to the propofol group (P = 0.01 for both). No significant differences were observed in the overall alfentanil dosages administered, bradycardia, bodily movement, or time to losing consciousness between the two groups. Conclusion: In patients who underwent cold knife cervical conization, remimazolam-alfentanil anesthesia was associated with a reduced incidence of intraoperative cardiopulmonary adverse events compared with propofol-alfentanil anesthesia.

A comparative study on the efficacy and safety of propofol combined with different doses of alfentanil in gastroscopy: a randomized controlled trial.

PURPOSE: Propofol can be used alone or in combination with opioids during gastroscopy. This study aimed to assess the efficacy and safety of intravenous propofol and different doses of alfentanil in patients undergoing gastroscopy. METHODS: A total of 300 patients undergoing sedative gastroscopy were randomly divided into four groups, and 0.9% saline (group A), 2 µg/kg alfentanil (group B), 3 µg/kg alfentanil (group C) or 4 µg/kg alfentanil (group D) were injected intravenously 1 min before the intravenous injection of 1.5 mg/kg propofol. If body movement and coughing occurred during the procedure, 0.5 mg/kg propofol would be administered intravenously. The primary outcome (awakening time) and secondary outcomes were recorded and analyzed, including hemodynamic changes, the incidences of body movement, coughing, hypoxemia, hypotension, hypertension, bradycardia, tachycardia, nausea and vomiting, drowsiness and dizziness. RESULTS: Patients in group C (7.0 [5.0 to 8.0] min) and group D (6.0 [5.0 to 7.0] min) woke up significantly earlier than those in group A (8.0 [6.0 to 10.0] min) (P < 0.001). Patients in group A experienced more body movement (P = 0.001) and coughing (P < 0.001) than the other groups. With the increasing dose of alfentanil, the morbidity of hypotension and bradycardia increased significantly (P = 0.001), while the incidence of dizziness decreased significantly (P = 0.037). The incidences of hypoxemia, tachycardia, drowsiness, nausea and vomiting were similar among the four groups (P > 0.05). CONCLUSIONS: Intravenous 1.5 mg/kg propofol combined with 3 µg/kg alfentanil is more suitable for patients undergoing gastroscopy, and the dose of alfentanil can be reduced according to the patient's actual physical condition.

Alternatives to remifentanil for the analgesic component of total intravenous anaesthesia: a narrative review.

Propfol-remifentanil-based total intravenous anaesthesia has dominated recent clinical practice due to its favourable pharmacokinetic profile. Interruption in remifentanil supply has presented an opportunity to diversify or even avoid the use of opioids and consider adjuncts to propofol-based total intravenous anaesthesia. Propofol, while a potent hypnotic, is not an effective analgesic. The administration of opioids, along with other adjuncts such as α-2 adrenoceptor agonists, magnesium, lidocaine, ketamine and nitrous oxide provide surgical anaesthesia and avoids large doses of propofol being required. We provide an overview of both target-control and manual infusion regimes for the alternative opioids: alfentanil, sufentanil and fentanyl. The optimal combination of hypnotic-opioid dose, titration sequence and anticipated additional postoperative analgesia required depend on the chosen combination. In addition, we include a brief discussion on the role of non-opioid adjuncts in total intravenous anaesthesia, suggested doses and expected reduction in propofol dose.

Propofol combined with alfentanil for general anesthesia in vocal cord polypectomy under suspension laryngoscopy.

OBJECTIVE: To investigate the clinical effect of propofol combined with alfentanil in vocal cord polypectomy under suspension laryngoscopy. METHODS: A total of 308 patients undergoing vocal cord polypectomy under suspension laryngoscopy in the First Affiliated Hospital of Nanchang University were included in this prospective study, and the patients were randomly divided into an observation group and a control group. Patients in the observation group received alfentanil combined with propofol, while those in the control group were anesthetized with sufentanil combined with propofol. The heart rate (HR), mean arterial pressure (MAP), real portfolio project (RPP), and Steward postanesthetic recovery scores were compared between the two groups before anesthesia induction (T0), at intubation (T1), 5 min after intubation (T2), at the time of placing suspension laryngoscopy (T3), 1 min after placing the suspension laryngoscopy (T4), 1 min after extraction of support laryngoscope (T5), and 1 min after extubation (T6). In addition, the propofol dosage and peripheral plasma levels of epinephrine (E) and norepinephrine (NE) were also compared between the groups. RESULTS: The MAP, HR, and RPP of the patients in the observation group were higher than those in the control group at T1-T5 (all P<0.05), while there was no statistical difference at T0 and T6 (all P>0.05). The Steward postanesthetic recovery scores and the propofol dosage in the observation group were lower than those in the control group. In addition, there was a statistically significant difference in the E and NE levels between the two groups after surgery (P<0.001). There was also an interaction effect between the groups and among the time points (both P<0.001). CONCLUSION: Alfentanil can reduce the fluctuation of hemodynamics during vocal cord polypectomy under suspension laryngoscopy, and therefore improve anesthesia effect. Simultaneously, the usage of propofol was reduced, as well as the stress levels. CLINICAL TRIAL NUMBER: ChiCTR2100054186.

Median effective dose of alfentanil combined with propofol inhibiting responses to laryngeal mask airway insertion in children / 中华麻醉学杂志

Objective:To determine the median effective dose(ED 50) of alfentanil combined with propofol inhibiting responses to the laryngeal mask airway(LMA) insertion in children. Methods:American Society of Anesthesiologists Physical Status classification Ⅰ children, aged 6-10 yr, with body mass index of 18-24 kg/m 2, undergoing facial skin pigmented nevus resection, were selected. Propofol(target plasma concentration 3 μg/ml) was given by the target-controlled infusion, alfentanil was intravenously injected, 2 min later LMA was inserted, and anesthesia was maintained with 2%-3% sevoflurane until the end of surgery. The dose of alfentanil was determined by the up-and-down sequential method, the initial dose of alfentanil was 15 μg/kg, when the response to LMA insertion was positive/negative, the dose of alfentanil increased/decreased by 1 μg/kg in the next case. The LMA insertion response was defined as swallowing, bucking, body movement occurred during insertion of the LMA, and this process was repeated until 7th turning points appeared. The ED 50 and 95% confidence interval of alfentanil combined with propofol inhibiting responses to LMA insertion in children were calculated using probit method. Results:The ED 50 of alfentanil combined with propofol inhibiting responses to LMA insertion was 13.18(95% confidence interval 12.43-13.79) μg/kg in children. Conclusions:The ED 50 of alfentanil combined with propofol inhibiting responses to LMA insertion is 13.18 μg/kg in children.