Prevention of pain on injection of propofol: systematic review and meta-analysis

Effect of injection pain and withdrawal movement of propofol and rocuronium in the induction of anaesthesia on postoperative pain outcomes in gynaecological laparoscopic surgery: a prospective observational study

INTRODUCTION

The experience and perception of pain may vary among individuals.This prospective cohort study aimed to determine the impact of injection pain/withdrawal movement of propofol and rocuronium in the induction of anaesthesia on postoperative pain outcomes in gynaecological laparoscopic surgery.

METHODS

A total of 100 patients aged 19-60 years received propofol and rocuronium injections for the induction of anaesthesia. The incidence of propofol injection pain (PIP) and rocuronium-induced withdrawal movement (RIWM), postoperative pain scores and total opioid consumption were evaluated, and the associations between PIP/RIWM and postoperative pain outcomes were determined.

RESULTS

Visual analogue scale (VAS) for pain after surgery and total opioid consumption after surgery were significantly higher in patients with PIP or RIWM than in patients without PIP or RIWM. The correlations of PIP/RIWM with VAS at 1 h, VAS at 24 h and total opioid consumption were significant and weakly positive ( r = 0.249, r = 0.234, r = 0.22 and r = 0.234, respectively). The RIWM correlated more positively with pain score compared to PIP at 1 h ( r = 0.408 vs. r = 0.234), PIP at 24 h ( r = 0.398 vs. r = 0.227) and with total opioid consumption for 48 h after surgery ( r = 0.457 vs. r = 0.234).

CONCLUSION

During anaesthesia induction, the occurrence of PIP and RIWM may predict the severity of postoperative pain and total opioid consumption, with RIWM emerging as a stronger predictor than PIP.

Characteristics that increase the risk for pain on propofol injection

BACKGROUND

Propofol for anesthesia has become increasingly popular for endoscopic procedures. However, pain on propofol injection (POPI) remains an issue with administration. The primary endpoint of this study was to identify patient characteristics and factors, such as IV site and gauge, that could predict the occurrence of POPI.

METHODS

This was a prospective chart review study of 291 patients undergoing endoscopic procedures. The patient's demographics, intravenous (IV) site, and gauge were extrapolated. POPI was scored 0-3: 0 for no pain, 1 for minimal discomfort or awareness of sensation, 2 for discomfort but manageable/tolerable, and 3 for severe discomfort with writhing.

RESULTS

291 patient charts were reviewed. One patient was excluded for a lower extremity IV site. 225 (77.6%) had no pain, 48 (16.6%) grade 1 pain, 16 (5.5%) grade 2 pain, and 1 (0.3%) grade 3 pain. 137, 13, and 140 patients respectively had antecubital (AC), forearm, and hand IVs. Zero patients with an AC IV experienced a score greater than 1. Compared to AC, forearm IVs with pain of 2-3 had a univariate odds ratio (OR) of 11.3 (0.66,1.92; p-value < 0.001), and hand IVs had a univariate OR of 18.8 (2.46,143.3; p-value < 0.001) with a multivariable OR 15.2 (1.93,118.9; p-value 0.004). Patients with anxiety/depression and pain had a univariate OR 2.31 (1.09, 7.27; p-value 0.031) with a multivariable OR 2.85 (1.06, 7.74; p-value 0.039). SSRI/SNRI use had a univariate OR 1.56 (0.57,4.28; p-value 0.38). Alcohol use had a univariate OR 1.24 (0.39,3.91; p-value 0.71). Narcotic use had a Univariate OR 6.18 (1.49,25.6; p-value 0.012). Diabetic patients had a univariate OR of 1.42 (0.45,4.48; p-value 0.55). Chronic pain had a univariate OR of 3.11 (1.04,9.28; p-value 0.042). Females had a univariate OR 0.98 (0.37,2.63; p-value 0.95).

CONCLUSION

This study identified potential characteristics for having POPI. The incidence of POPI was statistically significant in patients with hand and forearm IVs compared to AC IV sites, larger IV gauges, history of depression/anxiety, history of chronic narcotic use, fibromyalgia, and chronic pain syndromes. This shows the potential of premedicating with analgesics or using AC sites on these select patients to help reduce the risk of POPI.

Avoiding pain during propofol injection in pediatric anesthesia: Hypnoanalgesia of the hand versus intravenous lidocaine

INTRODUCTION

Pain related to injection of propofol during induction of anesthesia decreases from 66.8% without prevention, to 22-31% of cases when lidocaine is associated. Hypnoanalgesia of the hand is currently used for painful procedures in children but has never been evaluated in this indication. The primary aim of this prospective randomized single-blind study was to evaluate the efficacy of hypnoanalgesia of the hand for the prevention of moderate to severe pain during intravenous injection of propofol alone in comparison to lidocaine admixture. The secondary aim was to compare the global satisfaction of children in both methods.

PATIENTS AND METHODS

One hundred patients aged 7-14 years, ASA 1-2, admitted for scheduled surgery under general anesthesia were randomized into two groups. Group L received a mixture of 1% propofol (3 mg/kg) and 1% Lidocaine (0.3 mg/kg). Group H received 1% propofol (3 mg/kg) after hypnoanalgesia of the hand realized by a single experimented operator. A video was made in order to evaluate the pain related to propofol injection by a blinded observer using the 4-point score of Cameron (painful ≥ 2). The global satisfaction of children was evaluated in postanesthesia care unit and documented if visual analog score was <7/10.

RESULTS

Ninety-six patients were analyzed. The rate of painful patients did not differ significantly between groups (8.5% in group H [n = 47] vs 6.1% in group L [n = 49], OR= 0.70; 95% CI [0.13-3.35], p = 0.65), nor did the rate of nonsatisfied patients (10.6 in group H vs. 12.2% in group L, OR = 0.85; 95% CI [0.19-3.65], p = 1).

CONCLUSIONS

Our results suggest that hypnoanalgesia of the hand alone is effective to prevent the pain related to propofol injection in children. No significant difference was found in comparison with lidocaine admixture nor for pain or satisfaction.

Efficacy and safety of ciprofol versus propofol for induction and maintenance of general anesthesia: a systematic review and meta-analysis

BACKGROUND

Propofol has been the gold standard for anesthesia induction and maintenance due to its rapid onset and favorable pharmacokinetic properties. However, the search for alternative agents with improved safety and efficacy has led to the emergence of ciprofol (HSK3486), a structural analog of propofol. This systematic review and meta-analysis aim to comprehensively assess the safety and efficacy of ciprofol compared to propofol for anesthesia induction and maintenance in adult patients undergoing surgical procedures.

METHODS

This study included only double-arm RCTs in which participants were aged eighteen or older undergoing surgery. For the statistical analysis of the extracted data, we employed RevMan 5.4.1.

RESULTS

Ciprofol demonstrated a promising trend of higher anesthesiologists' satisfaction during the induction phase (MD 0.14, 95%, CI - 0.28 to 0.56, p = 0.51), whereas Propofol was favored during maintenance. Propofol also exhibited advantages with a shorter time to successful anesthesia induction (MD 0.08 min, 95% CI 0.00 to 0.15, p = 0.04), and quicker attainment of full alertness (MD 0.11 min, 95% CI - 1.29 to 1.52, p = 0.87), suggesting its efficiency in clinical practice. Importantly, there were no significant disparities in the success rate of anesthesia.

CONCLUSION

Both ciprofol and propofol demonstrate comparable efficacy and safety for anesthesia induction and maintenance in adult patients undergoing surgery. While propofol provides a faster onset of induction, ciprofol exhibits advantages in terms of pain management. Clinicians should consider these findings when selecting anesthetic agents, and tailoring choices to individual patient needs and clinical scenarios.

Comparison of the Efficacy of HSK3486 and Propofol for Induction of General Anesthesia in Adults: A Multicenter, Randomized, Double-blind, Controlled, Phase 3 Noninferiority Trial

BACKGROUND

Propofol is an intravenous anesthetic associated with hypotension, respiratory depression, and injection-site pain. HSK3486 injectable emulsion (ciprofol) is a 2,6-disubstituted phenol derivative with fast onset and quick, stable recovery. Previous studies support HSK3486 as an effective, safe anesthetic with substantially less injection-site pain than propofol. The primary objective of this study was to investigate the noninferiority of HSK3486 compared with propofol in successful general anesthesia induction.

METHODS

Two hundred fifty-five participants were enrolled in HSK3486-304, a multicenter, randomized (2:1), double-blind, propofol-controlled, phase 3 study evaluating HSK3486 for general anesthesia induction in adults undergoing elective surgery with tracheal intubation. The primary endpoint was successful anesthesia induction, defined as 1 or less on the Modified Observer's Assessment of Alertness/Sedation scale. Key secondary endpoints were proportion of participants with injection-site pain on the Numerical Rating Scale of 1 or greater and a composite endpoint, including the proportion of participants successfully induced while maintaining the desired anesthetic depth and without substantial cardiac and respiratory events. Safety endpoints included adverse events, abnormal vital signs, and injection-site pain.

RESULTS

Two hundred fifty-one participants (HSK3486, n = 168; propofol, n = 83) were included in the analyses. General anesthesia was successfully induced in 97.0% versus 97.6% of participants with HSK3486 and propofol, respectively. The difference in success rate was -0.57% (95% CI, -5.4 to 4.2%); the noninferiority boundary of -8% was not crossed. Thirty participants (18.0%) had injection-site pain with HSK3486 versus 64 (77.1%) with propofol (P < 0.0001). Eighty-one participants (48.2%) with HSK3486 versus 42 (50.6%) with propofol (P = 0.8780) satisfied the composite endpoint. When injection-site pain was excluded, the incidence of treatment-emergent adverse events related to study drug was 17.9% for HSK3486 and 14.5% for propofol.

CONCLUSIONS

The study met its primary objective and endpoint, demonstrating noninferiority of HSK3486 compared with propofol in successful anesthetic induction. Substantially less injection-site pain was associated with HSK3486 than with propofol.

EDITOR’S PERSPECTIVE

Remimazolam versus propofol for sedation in gastrointestinal endoscopy and colonoscopy within elderly patients: a meta-analysis of randomized controlled trials

PURPOSE

Propofol has become the sedative of choice for endoscopy and colonoscopy. However, it has shown associations with various adverse effects, specifically in the geriatric population. In contrast, remimazolam is a novel benzodiazepine, demonstrating a superior clinical safety profile. Hence, this systematic review and meta-analysis aims to clarify the efficacy and safety of remimazolam versus propofol in elderly patients (≥ 60 years) undergoing gastrointestinal endoscopic and colonoscopy procedures.

METHODS

Electronic databases including PubMed, Cochrane Library, ScienceDirect, and Google Scholar were explored from inception till January 7, 2024. The Cochrane Risk of Bias Tool for Randomized Controlled Trials (RoB-2) was utilized to evaluate the quality of each included study reported in this meta-analysis.

RESULTS

Seven randomized control trials were included, resulting in the pooling of 1,466 patients (remimazolam: 731 patients; propofol: 735 patients). Propofol demonstrated a significantly lower time to loss of consciousness (P < 0.00001, 4 studies, 784 patients) and a greater sedation success after first dose (P = 0.05, 5 studies, 1,271 patients). Remimazolam reported a significantly lower risk of bradycardia (P = 0.02, 5 studies, 1,323 patients), hypoxemia (P < 0.00001, 6 studies, 1,389 patients), and pain on injection site (P < 0.00001, 5 studies, 1,184 patients). No statistically significant differences in sedation time, number of supplemental doses, procedural parameters, and other adverse outcomes were reported.

CONCLUSION

As per the results of our analyses, propofol demonstrated comparatively superior efficacy, however, remimazolam demonstrated comparatively superior safety. The debatable evidence generated from this meta-analysis may not currently be powerful enough to advocate for the use of remimazolam in elderly patients undergoing gastrointestinal procedures; hence, further comprehensive studies are necessary in order to arrive at a robust conclusion.

Effect of intravenous lidocaine on the ED50 of propofol induction dose in elderly patients undergoing painless gastroscopy: a prospective, randomized, double-blinded, controlled study

BACKGROUND

Intravenous lidocaine could be a potential alternative adjuvant to propofol-based sedation for gastroscopy in elderly patients. This study aimed to evaluate the effect of intravenous lidocaine on the median effective dose (ED50) of propofol induction dose in elderly patients undergoing painless gastroscopy.

METHODS

The study included 70 patients aged ≥ 60 years undergoing painless gastroscopy with 64 randomly assigned to either group L (2% lidocaine 1.5 mg/kg, n = 31) or group N (equal volume normal saline, n = 33). All patients received propofol induction following 0.1 μg/kg intravenous sufentanil. The Dixon "up-and-down" sequential method was used, with a 1.5 mg/kg initial induction dose of propofol followed by a 0.1 mg/kg sequential variable dose. The primary endpoint was the ED50 of the propofol induction dose. The total propofol dose, recovery time, adverse events, and local anesthetic intoxication reactions were also recorded.

RESULTS

The ED50 of propofol induction dose was 0.670 (95% confidence interval [CI] 0.216-0.827) mg/kg in group L and 1.118 (95% CI 0.803-1.232) mg/kg in group N. There was a statistically significant difference between the two groups (p < 0.001). The incidence of hypotension and propofol injection pain were lower in group L than in group N (p < 0.05). Furthermore, the orientation recovery time in group L was shorter compared to group N (p < 0.05). None of the participants in group L observed local anesthetic intoxication reactions after receiving lidocaine.

CONCLUSIONS

The administration of intravenous lidocaine to elderly patients undergoing painless gastroscopy resulted in a significant 40% reduction in the ED50 of propofol induction dose, which may be related to the decreased incidence of hypotension and injection pain, as well as the improved post-gastroscopy orientation recovery.

TRIAL REGISTRATION

ChiCTR, ChiCTR2200065530. Registered on 08 November 2022.

The Relationship between Pre-Anesthetic Analgesia and Nociception (ANI) and Propofol Injection Pain among Patients Receiving Remifentanil: A Prospective, Randomized, Controlled Study

Background and Objectives: The analgesia/nociception index (ANI) potentially monitors nociceptive status during anesthesia, but its link to preoperative pain sensitivity is unclear. We investigated the relationship between pre-anesthetic ANI scores and propofol injection pain (PIP) in patients receiving remifentanil. Materials and Methods: This study included 124 male patients aged 19-60 undergoing general anesthesia (ASA class I or II). Patients were randomized to group R (n = 62, remifentanil 4 ng/mL) or group C (n = 62, saline). The primary outcome was the association between PIP and ANI. Secondary outcomes included the incidence and severity of PIP or rocuronium-induced withdrawal movement (RIWM) and their association with ANI. Results: PIP and RIWM incidence and severity were lower in group R than in group C. A weak negative correlation between PIP and ANI at pre-induction (rpb = -0.21, p = 0.02, rpb = -0.37, p < 0.01) and a moderate negative correlation during propofol injection (rpb = -0.48, p = 0.02) were observed. A significant negative correlation was found between RIWM and ANI during rocuronium injection (τb = -0.61, p < 0.01). AUC, cut-off value, specificity, and sensitivity in ANI at pre-induction for predicting PIP were 0.67 (p = 0.02), 59, 76%, and 55%, respectively. AUC, cut-off value, specificity, and sensitivity in ANI during propofol injection for PIP were 0.77 (p < 0.01), 65, 81%, and 67%, respectively. Conclusions: ANI scores demonstrated significant differences between groups, suggesting potential predictive value for PIP despite the low pre-induction AUC value. This study highlights the potential of using ANI scores to predict and manage PIP in patients receiving remifentanil.

The safety of remimazolam versus propofol in gastroscopic sedation: a meta-analysis

BACKGROUND

This meta-analysis was designed to compare the safety and efficiency of remimazolam with those of propofol in patients undergoing gastroscope sedation.

METHODS

We searched PubMed, Cochrane Library, Embase, Ovid, Wanfang Database, China National Knowledge Infrastructure, SINOMED, and ClinicalTrials.gov for studies that reported on remimazolam versus propofol for gastroscope sedation from establishment to February 25, 2023. The sedative efficiency and the incidence of adverse events were assessed as outcomes. Version 2 of the Cochrane risk-of-bias assessment tool was used to assess the risk of bias. Review Manager 5.4 and STATA 17 were used to perform all statistical analyses.

RESULTS

A total of 26 randomized controlled trials involving 3,641 patients were included in this meta-analysis. The results showed that remimazolam had a significantly lower incidence of respiratory depression (risk ratio [RR] = 0.40, 95% confidence interval [CI]: 0.28-0.57; p < 0.01, GRADE high), hypoxemia (RR = 0.34, 95% CI: 0.23-0.49; p < 0.01, GRADE high), bradycardia (RR = 0.34, 95% CI: 0.23-0.51; p < 0.01, GRADE high), dizziness (RR = 0.45, 95% CI: 0.31-0.65; p < 0.01, GRADE high), injection site pain (RR = 0.06, 95% CI: 0.03-0.13; p < 0.01, GRADE high), nausea or vomiting (RR = 0.79, 95% CI: 0.62-1.00; p = 0.05, GRADE moderate), and hypotension (RR = 0.36, 95% CI: 0.26-0.48; p < 0.01, GRADE low).

CONCLUSIONS

Remimazolam can be used safely in gastroscopic sedation and reduces the incidence of respiratory depression, hypoxemia, bradycardia, injection site pain, and dizziness compared with propofol, and doesn't increase the incidence of nausea and vomiting.

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).

Efficacy and safety of ciprofol (HSK3486) for procedural sedation and anesthesia induction in surgical patients: A systematic review and meta-analysis

Background

Ciprofol (HSK3486) is a novel gamma-aminobutyric acid type A (GABAA) receptor agonist that has attracted wide attention because of its lower injection pain and fewer adverse events. We summarized all available evidence and analyzed the efficacy and safety of ciprofol during procedural sedation and anesthesia induction.

Methods

An electronic search of PubMed, Embase, Cochrane Library, Web of Science, Google Scholar, Science Direct, the Chinese National Knowledge Infrastructure, Wan Fang Data, and the VIP Chinese Journal Service platform was conducted from inception of databases to March 1, 2023. Risk ratio (RR) and mean difference (MD) with 95 % confidence interval (CI) were used separately for binary categorical and continuous variables. We performed trial sequential analysis and the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology to judge the certainty of evidence.

Results

Fifteen randomized controlled trials with 2441 patients were included in this study. Ciprofol showed similar advantages to propofol in terms of induction success rate (RR = 1, 95 % CI = 0.99, 1.01, moderate certainty) and induction time (MD = 3.31, 95 % CI = -0.34, 6.95, low certainty), but did not increase the incidence of adverse events (RR = 0.88, 95 % CI = 0.78, 1.00, very low certainty), such as bradycardia (RR = 0.96, 95 % CI = 0.77, 1.21, high certainty), hypoxia (RR = 0.79, 95 % CI = 0.46, 1.37, p = 0.40, moderate certainty) and other adverse events. Although it may be associated with a longer time to be fully alert (MD = 1.22, 95 % CI = 0.32, 2.12, very low certainty), ciprofol significantly reduced injection pain (RR = 0.15, 95 % CI 0.09, 0.24, low certainty) and may have reduced the incidence of hypotension (RR = 0.77, 95 % CI = 0.63, 0.94, low certainty) and respiratory depression (RR = 0.29, 95 % CI = 0.15, 0.56, moderate certainty).

Conclusion

Ciprofol and propofol had similar effects on most outcomes. While the time to full alertness may be prolonged, injection pain was significantly reduced, and hypotension and respiratory depression may be reduced compared with propofol. We believe that ciprofol is an effective alternative to intravenous anesthetic agents.

Control Volume Analysis of the Infusion Rate in Cephalic and Median Cubital Veins Based on Infusion Bag Height and Peripheral Venous Catheter Inner Diameter: Application of Bernoulli's Equation and Consideration of Frictional Forces

Purpose

This pilot study aimed to provide basic data on intravenous infusion nursing by analyzing the infusion rate in the cephalic and median cubital veins depending on the height of the infusion bag and inner diameter of the peripheral venous catheter (PVC).

Methods

While infusing 0.9% normal saline at 22 °C (room temperature) into elbow cephalic and median cubital veins, the infusion rate may be controlled by adjusting the fluid height and PVC diameter. To assess the validity of the laminar flow assumption, the study estimated the Reynolds number (Re) using the velocity obtained by applying Bernoulli's equation considering the friction coefficient.

Results

At a constant fluid height, the infusion rate increased with increasing PVC diameter. At a constant PVC diameter, the infusion rate increased with increasing fluid height. In a comparison between the cephalic and median cubital veins at constant fluid height and PVC diameter, the solution was infused at a higher rate into the cephalic vein, which was under lower venous pressure.

Conclusion

The analysis of the infusion rate according to fluid height and PVC diameter provided basic data on intravenous infusion nursing. The results are expected to provide evidence for the standardization of intravenous infusion nursing.

Efficacy and safety of remimazolam besilate for sedation in outpatients undergoing impacted third molar extraction: a prospective exploratory study

BACKGROUND

Dental treatments often cause anxiety, fear, and stress in patients. Intravenous sedation is widely used to alleviate these concerns, and various agents are employed for sedation. However, it is important to find safer and more effective sedation agents, considering the adverse effects associated with current agents. This study aimed to investigate the efficacy and safety of remimazolam besilate (hereinafter called "remimazolam") and to determine the optimal dosages for sedation in outpatients undergoing dental procedures.

METHODS

Thirty-one outpatients aged 18-65 years scheduled for impacted third molar extraction were included in the study. Remimazolam was administered as a single dose of 0.05 mg/kg followed by a continuous infusion at a rate of 0.35 mg/kg/h, with the infusion rate adjusted to maintain a sedation level at a Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score of 2-4. The primary endpoint was the sedation success rate with remimazolam monotherapy, and the secondary endpoints included induction time, recovery time, time until discharge, remimazolam dose, respiratory and circulatory dynamics, and frequency of adverse events.

RESULTS

The sedation success rate with remimazolam monotherapy was 100%. The remimazolam induction dose was 0.08 (0.07-0.09) mg/kg, and the anesthesia induction time was 3.2 (2.6-3.9) min. The mean infusion rate of remimazolam during the procedure was 0.40 (0.38-0.42) mg/kg/h. The time from the end of remimazolam administration to awakening was 8.0 (6.7-9.3) min, and the time from the end of remimazolam administration to discharge was 14.0 (12.5-15.5) min. There were no significant respiratory or circulatory effects requiring intervention during sedation.

CONCLUSIONS

Continuous intravenous administration of remimazolam can achieve optimal sedation levels without significantly affecting respiratory or circulatory dynamics. The study also provided guidance on the appropriate dosage of remimazolam for achieving moderate sedation during dental procedures. Additionally, the study findings suggest that electroencephalogram monitoring can be a reliable indicator of the level of sedation during dental procedural sedation with remimazolam.

TRIAL REGISTRATION

The study was registered in the Japan Registry of Clinical Trials (No. jRCTs061220052) on 30/08/2022.

The study of different dosages of remazolam combined with sufentanil and propofol on painless gastroscopy: A randomized controlled trial

BACKGROUND

Gastroscopy is one of the most commonly used diagnostic modalities for upper gastrointestinal disorders. Remazolam besylate, a new type of ultrashort-acting benzodiazepine drug, has been less studied in gastroscopy. In this study, we studied the efficacy and safety of remazolam combined with propofol for painless gastroscopy.

METHODS

This is a single-center, randomized controlled clinical trial. Hundred patients undergoing painless gastroscopy were included in this study and randomly divided into 2 groups (n = 50 per group): the remazolam 3 mg group (R3 group) and the remazolam 6 mg group (R6 group). Sufentanil, remazolam, and propofol are used to anesthetize the patients, and then, the effects of different dosages of remazolam on these patients are compared and analyzed. The patient's general condition, vital signs at different times, the dosage of propofol (mg) and additional times, complications, duration of gastroscopy (minute), awakening time (minute), residence time in the resuscitation room (minute), and adverse reactions were recorded.

RESULTS

R3 group systolic blood pressure and diastolic blood pressure are more stable (P < .05); The number of additional propofol in R6 group was less (P < .05). The incidence of hypotension was lower in R3 group, as well as the time of awakening and staying in the resuscitation room were shorter (P < .05).

CONCLUSION

Remazolam 3mg combined with sufentanil and propofol have less effect on hemodynamics in painless gastroscopy, and the patients have shorter awakening time.

The safety and efficacy of remimazolam tosylate combined with propofol in upper gastrointestinal endoscopy: A multicenter, randomized clinical trial

INTRODUCTION

Hypotension is the most common adverse event under propofol-mediated sedation and is possible to cause varying degrees of damage to patients. Whereas remimazolam has a poorer sedative effect than propofol.

AIM

The aim of this study was to explore the advantages of the combination of remimazolam tosylate and propofol.

METHODS

304 patients were divided into the remimazolam tosylate group (RT group), the propofol group (P group), and the remimazolam tosylate plus propofol group(R+T group). The primary outcome was the incidence of hypotension. Secondary outcomes included the results of sedation and recovery. The safety results mainly include the incidence of Hypotension, adverse respiratory events, postoperative nausea and vomiting, hiccup, cough, body movement and bradycardia.

RESULTS

The incidence of hypotension was 56.7% in the P group, 12.6% in the RT group, and 31.3% in the R+P group, three groups of pairwise comparisons showed statistical differences, with P< 0.001. The incidence of body movement was significantly higher in the RT group (26.1%) than in the P group (10.3%) and the R+P group (12.5%), P = 0.004. The endoscopist satisfaction was higher in the P (3.87±0.44) and R+P (3.95±0.22)groups than in the RT(3.53±0.84) group. The incidence of adverse events, in descending order, was P group, RT group, and R+P group (93.8%vs.61.3%vs.42.7%).

CONCLUSION

Co-administration had fewer adverse events than propofol monotherapy, also had a better sedative effect and higher endoscopist satisfaction than remimazolam monotherapy.

TRIAL REGISTRATION

Clinical trial registration number: NCT05429086.

Prevention of pain on injection of propofol using ice gel pack versus pre-treatment with lignocaine: a randomized controlled trial

PURPOSE

Regardless of the positive attributes of propofol, it is frequently associated with pain on injection. We compared the efficacy of topical cold thermotherapy using an ice gel pack with intravenous lignocaine pre-treatment for reducing pain on propofol injection.

METHODS

This single-blinded randomized controlled trial was conducted in 200 American Society of Anesthesiologists physical status I, II, and III patients scheduled for elective/emergency surgery under general anesthesia. The patients were randomized into two groups: the Thermotherapy group- receiving an ice gel pack proximal to the intravenous cannula for 1 min, or the Lignocaine group-receiving 0.5 mg/kg of lignocaine administered intravenously, with occlusion proximal to the site of the intravenous cannula for 30 s. The primary objective was to compare the overall incidence of pain after propofol injection. The secondary objectives included the incidence of discomfort on the application of an ice gel pack, comparison of dose of propofol needed for induction, and hemodynamic changes at induction, between the two groups.

RESULTS

Fourteen patients in the lignocaine group and 15 patients in the thermotherapy group reported pain. The incidence of pain and the distribution of pain scores were comparable among groups (p = 1.00). Patients of the lignocaine group required significantly less amount of propofol for induction as compared to the thermotherapy group (p = 0.001).

CONCLUSION

Topical thermotherapy using an ice gel pack was not found superior to lignocaine pre-treatment in alleviating pain on injection of propofol injection. However, topical cold therapy using an ice pack remains a non-pharmacological technique that is easily available, reproducible, and cost-effective. Further studies are required to prove its equivalence to lignocaine pre-treatment.

TRIAL REGISTRATION

CTRI (CTRI/2021/04/032950).

Remimazolam versus propofol for procedural sedation: a meta-analysis of randomized controlled trials

Background

To improve patient tolerability and satisfaction as well as minimize complications, procedural sedation has been widely used. Propofol is the most widely used agent for induction of anesthesia and sedation by anesthesiologists. With a different mechanism compared to propofol, remimazolam is a new short-acting GABA-A receptor agonist. It is an ester-based benzodiazepine. This meta-analysis aims to clarify the efficacy and safety of remimazolam versus propofol for procedure sedation.

Methods

Electronic databases were searched for randomized controlled trials (RCTs) comparing efficacy or safety of remimazolam versus propofol. Meta-analysis were conducted using RStudio with "metafor" package with random-effects model.

Results

A total of twelve RCTs were included in the meta-analysis. The pooled results demonstrated that patients with remimazolam for procedural sedation had lower risk of bradycardia (OR 0.28, 95% CI [0.14-0.57]), hypotension (OR 0.26, 95% CI [0.22-0.32]), and respiratory depression (OR 0.22, 95% CI [0.14-0.36]). There was no difference in the risk of developing postoperative nausea and vomiting (PONV) (OR 0.65, 95% CI [0.15-2.79]) and dizziness (OR 0.93, 95% CI [0.53-1.61]) between the remimazolam and propofol groups. Using remimazolam for procedural sedation is significantly associated with less injection pain compared to propofol (OR 0.06, 95% CI [0.03-0.13]). Regarding the sedation efficacy, there was no difference in sedation success rate or time to loss of consciousness, recover and discharge between the remimazolam and the propofol groups.

Conclusions

Based on our meta-analysis, patients receiving procedural sedation with remimazolam had lower risk of bradycardia, hypotension, respiratory depression and injection pain compared with propofol. On the other hand, there was no difference in sedation success rate, risk of PONV, dizziness, time to LOC, recovery and discharge between these two sedatives.

PROSPERO registration number

CRD42022362950.

Comparison of the effects of remimazolam tosylate and propofol on postoperative delirium among older adults undergoing major non-cardiac surgery: protocol for a randomised controlled trial

INTRODUCTION

Postoperative delirium (POD) is a common cognitive disturbance in elderly individuals that is characterised by acute and fluctuating impairments in attention and awareness. Remimazolam tosylate is a novel, ultrashort-acting benzodiazepine, and there is limited evidence of its correlation with the incidence of early POD. The aim of this study is to evaluate the incidence of POD after anaesthesia induction and maintenance with remimazolam tosylate or propofol in elderly patients undergoing major non-cardiac surgery.

METHODS AND ANALYSIS

This is a single-centre, randomised controlled trial. 636 elderly patients undergoing major non-cardiac surgery will be enrolled and randomised at a 1:1 ratio to receive total intravenous anaesthesia with either remimazolam tosylate or propofol. The primary outcome is the incidence of POD within 5 days after surgery. Delirium will be assessed twice daily by the 3 min Diagnostic Interview for the Confusion Assessment Method or the Confusion Assessment Method for the intensive care unit (ICU) for ICU patients. Secondary outcomes are the onset and duration of delirium, cognitive function at discharge and within 1-year postoperatively, postoperative analgesia within 5 days, chronic pain at 3 months, quality of recovery and postoperative inflammatory biomarker levels.

ETHICS AND DISSEMINATION

The study was approved by the institutional ethics committee of the National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences (approval No. 22/520-3722). Written informed consent will be obtained from each patient before enrolment. The results of this trial will be presented at scientific conferences and in peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

ChiCTR2300067368.

Advantages of Sedation With Remimazolam Compared to Midazolam for the Removal of Impacted Tooth in Patients With Dental Anxiety

PURPOSE

Although midazolam is commonly used to sedate patients with dental anxiety, it has shortcomings that reduce the satisfaction of patients and doctors. The aim of this study was therefore to explore the advantages of remimazolam as a sedative.

METHODS

The study design was a prospective randomized controlled trial. Patients with dental anxiety and who were to undergo impacted tooth removal were randomized into remimazolam and midazolam groups. They were sedated with remimazolam or midazolam prior to receiving nerve blocker. The predictor variable was the type of sedative, while the primary outcome variables were the onset time, awakening time, recovery time, and postoperative side effects. Secondary outcome variables were the Modified Dental Anxiety Scale score before and after surgery, patient satisfaction and comfort levels scores, and doctor satisfaction level scores. Other variables included the patient demographics and the operation time. Data were analyzed using the Student's t-test, Mann-Whitney test, χ² test, and two-way repeated measurement ANOVA test (SPSS Version 25.0).

RESULTS

A total of 83 patients were included in this study, with 42 randomized to the remimazolam group and 41 to the midazolam group. There were no significant differences between the two groups in terms of demographic features and operation time. Patients in the remimazolam group had significantly shorter onset time, awakening time, and recovery time compared to those in the midazolam group (each P < .001). Postoperative side effects were more frequent in the midazolam group (P < .001). Following surgery, the Modified Dental Anxiety Scale scores in both groups were significantly lower than prior to surgery (P < .001). Satisfaction levels scores for the patients and doctor were higher in the remimazolam group than in the midazolam group (P < .001).

CONCLUSIONS

The use of remimazolam results in faster onset, more rapid recovery, and lower incidence of postoperative side effects compared to midazolam, leading to improved satisfaction for patients and doctors. Remimazolam therefore appears to have several advantages over midazolam for the sedation of patients with dental anxiety associated with the removal of impacted teeth.

The safety and efficacy of remimazolam tosylate for induction and maintenance of general anesthesia in pediatric patients undergoing elective surgery: Study protocol for a multicenter, randomized, single-blind, positive-controlled clinical trial

Introduction: Remimazolam is an ultra-short-acting benzodiazepine sedative agent commonly used in general anesthesia, procedural sedation, and intensive care unit (ICU) sedation. This study aimed to explore the efficacy and safety of remimazolam versus propofol for the induction and maintenance of general anesthesia in preschool-age children undergoing elective surgery. Methods and analysis: In this multicenter, randomized, single-blind, positive-controlled non-inferior clinical trial, one hundred ninety-two children aged 3-6 years will be randomly allocated as a 3:1 ratio into two groups: Group R with an intravenous dose of remimazolam 0.3 mg/kg for the induction of anesthesia followed by a constant infusion rate of remimazolam 1-3 mg/kg/h to maintain anesthesia, and Group P with an intravenous dose of propofol 2.5 mg/kg for the induction of anesthesia followed by a constant infusion rate of propofol 4-12 mg/kg/h to maintain anesthesia. The primary outcome will be the rate of the successful induction and maintenance of anesthesia. The secondary outcomes will include the time to LoC, the Bispectral Index (BIS) value, awakening time, extubation time, post-anesthesia care unit (PACU) discharge time, usage of additional sedative drugs during the induction period, usage of remedial drugs in PACU, emergence delirium, pain in PACU, behavior scores at day 3 after surgery, parental and anesthesiologists' satisfaction, and adverse events. Ethics and dissemination: This study has been approved by the ethics review boards at all participating hospitals. The Ethics Committee of the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University (Reference No. LCKY 2020-380, November 13, 2020) is the central ethics committee.

Advances in Analgosedation and Periprocedural Care for Gastrointestinal Endoscopy

The number and complexity of endoscopic gastrointestinal diagnostic and therapeutic procedures is globally increasing. Procedural analgosedation during gastrointestinal endoscopic procedures has become the gold standard of gastrointestinal endoscopies. Patient satisfaction and safety are important for the quality of the technique. Currently there are no uniform sedation guidelines and protocols for specific gastrointestinal endoscopic procedures, and there are several challenges surrounding the choice of an appropriate analgosedation technique. These include categories of patients, choice of drug, appropriate monitoring, and medical staff providing the service. The ideal analgosedation technique should enable the satisfaction of the patient, their maximum safety and, at the same time, cost-effectiveness. Although propofol is the gold standard and the most used general anesthetic for endoscopies, its use is not without risks such as pain at the injection site, respiratory depression, and hypotension. New studies are looking for alternatives to propofol, and drugs like remimazolam and ciprofol are in the focus of researchers' interest. New monitoring techniques are also associated with them. The optimal technique of analgosedation should provide good analgesia and sedation, fast recovery, comfort for the endoscopist, patients' safety, and will have financial benefits. The future will show whether these new drugs have succeeded in these goals.

Deep breathing alleviates propofol-induced pain: a prospective, randomized, single-blind study

PURPOSE

Propofol is commonly used to induce general anesthesia; however, the pain caused during propofol injection is a disadvantage. This study aimed to assess whether deep breathing attenuates propofol injection pain.

METHODS

This prospective, single-blind, randomized controlled study included 200 patients who were scheduled to undergo elective surgery under general anesthesia and randomly and equally divided them into group D and group C. The observers were not blinded to the pain-relieving modality, but each patient was blinded. Group D patients were requested to repeatedly take deep breaths throughout general anesthesia induction with propofol. Group C patients were requested to breathe in the usual manner. The intensity of propofol injection pain was evaluated using the visual analog scale (VAS). Furthermore, we recorded the patients' pain expressions, including grimace or hand-withdrawal, and the recalled pain measured using a VAS in the post-anesthetic care units (PACU).

RESULTS

Compared with patients in group C, those in group D showed significantly reduced VAS scores for propofol injection pain (20 [interquartile range (IQR): 0-48] vs. 37 [IQR 9-65], P = 0.017) and recalled pain in the PACU (16 [IQR 0-32] vs. 26 [IQR 0.5-51], P = 0.031). Further, the grimace incidence was significantly lower in group D (18%) than in group C (45%) (P < 0.001). There was no significant difference in the incidence of pain at induction, recalled pain, or hand-withdrawal.

CONCLUSIONS

Deep breathing could be an easy, safe, and inexpensive method for reducing pain during propofol injection.

Relationship between ANI and qNOX and between MAC and qCON during outpatient laparoscopic cholecystectomy using remifentanil and desflurane without muscle relaxants: a prospective observational preliminary study

This study was designed to investigate qCON and qNOX variations during outpatient laparoscopic cholecystectomy using remifentanil and desflurane without muscle relaxants and compare these indices with ANI and MAC. Adult patients undergoing outpatient laparoscopic cholecystectomy were included in this prospective observational study. Maintenance of anesthesia was performed using remifentanil targeted to ANI 50-80 and desflurane targeted to MAC 0.8-1.2 without muscle relaxants. The ANI, qCON and qNOX and desflurane MAC values were collected at different time-points and analyzed using repeated measures ANOVA. The relationship between ANI and qNOX and between qCON and MAC were analyzed by linear regression. The ANI was comprised between 50 and 80 during maintenance of anesthesia. Higher values of qNOX and qCON were observed at induction and extubation than during all other time-points where they were comprised between 40 and 60. A poor but significant negative linear relationship (r² = 0.07, p < 0.001) was observed between ANI and qNOX. There also was a negative linear relationship between qCON and MAC (r² = 0.48, p < 0.001) and between qNOX and remifentanil infusion rate (r² = 0.13, p < 0.001). The linear mixed-effect regression correlation (r²) was 0.65 for ANI-qNOX and 0.96 for qCON-MAC. The qCON and qNOX monitoring seems informative during general anesthesia using desflurane and remifentanil without muscle relaxants in patients undergoing ambulatory laparoscopic cholecystectomy. While qCON correlated with MAC, the correlation of overall qCON and ANI was poor but significant. Additionally, the qNOX weakly correlated with the remifentanil infusion rate. This observational study suggests that the proposed ranges of 40-60 for both indexes may correspond to adequate levels of hypnosis and analgesia during general anesthesia, although this should be confirmed by further research.

Ciprofol: A Novel Alternative to Propofol in Clinical Intravenous Anesthesia?

Ciprofol is a novel compound that was independently developed in China. According to the Chinese product instructions approved by the China National Medical Products Administration and the information of official website, indications for ciprofol include sedation and anesthesia during the surgical/procedure of nontracheal intubation, induction and maintenance of general anesthesia, and sedation during intensive care. Ciprofol is a short-acting intravenous sedative based on the structural modification of propofol. Ciprofol has high efficacy, good selectivity, and fewer adverse reactions, indicating good clinical application potential. A series of clinical studies have been conducted to evaluate the sedative effect of ciprofol in various procedures and settings, including gastroscopy and colonoscopy, fiber-optic bronchoscopy, general anesthesia in elective surgeries, and mechanical ventilation in intensive care units. This review summarizes the chemical structure, pharmacodynamics, and pharmacokinetic properties of ciprofol. We also assessed the efficacy and safety of ciprofol by synthesizing the relevant clinical trial data.

Transcutaneous electrical nerve stimulation for pain during propofol injection: a randomized clinical trial

Background

Propofol is a short-acting intravenous sedative widely used for procedural sedation and general anesthesia. However, pain during propofol injection is a distressing adverse effect. This study was designed to investigate whether transcutaneous electrical nerve stimulation (TENS) could reduce pain during propofol injection compared to sham TENS.

Methods

In a randomized controlled trial, 80 patients were allocated to two groups: the active TENS group received electrical stimulation via two electrodes on the venous cannulation site, whereas the sham TENS group received no stimulus. After 20 min following TENS, propofol 0.5 mg/kg pain was injected intravenously and pain was evaluated using a four-point score (0 = none, 1 = mild, 2 = moderate, 3 = severe). Adverse effects associated with TENS were also recorded.

Results

The overall incidence of pain during propofol injection was 47.5% in the TENS group and 87.5% in the sham group (P < 0.001). The incidence of moderate pain was significantly lower in the TENS group (7.5%) than in the sham TENS group (42.5%) (P < 0.001). There were no complications associated with TENS.

Conclusion

Pre-treatment with TENS significantly reduced the incidence and intensity of pain during propofol injection.

The effective doses of remimazolam besylate in the procedural sedation of endoscopic retrograde cholangiopancreatography

This study aimed to determine the values of the half-effective dose (ED50) and 95% effective dose (ED95) of remimazolam besylate used in the procedural sedation of endoscopic retrograde cholangiopancreatography (ERCP). Sixty patients who fulfilled the inclusion and exclusion criteria of this study were selected. Sufentanil was administered intravenously and remimazolam besylate was administered 2 min later. ERCP treatment was feasible when the modified alertness/sedation (MOAA/S) score was ≤2. If choking or movement occurred during duodenoscope placement, it was considered as a positive reaction. The dose was increased in the next patient; otherwise, it was considered as a negative reaction, and the dose was reduced in the next patient. The ED50 and ED95 values and 95% confidence interval (CI) of remimazolam besylate were calculated by Probit regression analysis. All 60 patients completed the trial. The ED50 and ED95 values of remimazolam besylate were 0.196 and 0.239 mg/kg, respectively, for the procedural sedation of ERCP. The time of MOAA/S score ≤ 2 was (82.58 ± 21.70) s, and the mean time of awakening was (9.03 ± 5.64) min. Transient hypotension was observed in two patients without medical intervention. The ED50 and ED95 values of remimazolam besylate used in the procedural sedation of ERCP were 0.196 and 0.239 mg/kg, and the dose of the medications has definite efficacy and good safety.

Esketamine prevents propofol-induced injection pain: Randomized controlled trial

Background: Propofol is widely used during anesthesia. However, propofol-induced injection pain (PIP) is considered an unpleasant perioperative outcome. This study aimed to investigate the efficacy of a mixture of esketamine and propofol in preventing propofol injection pain in patients undergoing general anesthesia.

Methods: This was a prospective, double-blind, multicenter, and randomized controlled trial. We included 252 adult patients with the American Society of Anesthesiologists physical status I to II who underwent surgery under general anesthesia. Patients were randomly allocated in a 1:1:1:1 ratio to four groups (n = 63 per group). Group NS received a mixture of 1% propofol (20 ml) and 0.9% normal saline (1 ml), group ESK-4 received a mixture of 1% propofol (20 ml) and esketamine 4 mg (diluted with 0.9% normal saline, 1 ml), group ESK-12 received a mixture of 1% propofol (20 ml) and esketamine 12 mg (diluted with 0.9% normal saline, 1 ml), and group ESK-20 received a mixture of 1% propofol (20 ml) and esketamine 20 mg (diluted with 0.9% normal saline, 1 ml) as sedative drugs during anesthesia. The primary outcome was the incidence and distribution of different degrees of PIP. The secondary outcomes were vital signs, characteristics of surgery and anesthesia, and adverse events.

Results: The incidence of PIP in group ESK-20 (33.3%) was significantly lower than that in groups NS, ESK-4, and ESK-12 (63.3%, 62.2%, and 49.1%, respectively; p &lt; 0.01). The incidence of moderate PIP in group NS (33.3%) and group ESK-4 (22.6%) was higher than that in groups ESK-12 (7.5%) and ESK-20 (6.7%). The incidence of severe PIP in group NS (6.7%) and group ESK-4 (9.4%) was higher than that in groups ESK-12 (1.9%) and ESK-20 (0%). There were no differences in the vital signs, characteristics of surgery and anesthesia, or adverse events between the groups.

Conclusion: Our results indicated that the esketamine–propofol admixture reduced the incidence of PIP in patients undergoing general anesthesia without severe side effects.

The efficacy and safety of ciprofol use for the induction of general anesthesia in patients undergoing gynecological surgery: a prospective randomized controlled study

Background

Ciprofol is a recently developed, short-acting γ-aminobutyric acid receptor agonist sedative that is more potent than propofol, but there have been few clinical studies of this agent to date. Here, we sought to examine the safety and efficacy of ciprofol use for the induction of general anesthesia in individuals undergoing gynecological surgery.

Methods

Women between the ages of 18 and 60 years (ASA physical status 1 or 2) who were scheduled to undergo elective gynecological surgery under general anesthesia were randomly assigned to two equally sized groups in which anesthesia induction was performed using either ciprofol or propofol. General anesthesia induction success rates were the primary outcome for this study, while secondary outcomes included changes in BIS during the 10 min following the first administration of the study drug, the duration of successful induction, and adverse event incidence.

Results

A total of 120 women were included in the study. A 100% rate of successful induction was achieved in both the ciprofol and propofol groups, with no significant differences between these groups with respect to the duration of successful induction (34.8 ± 15.5 s vs 35.4 ± 9.5 s, P = 0.832), the time to the disappearance of the eyelash reflex (33.7 ± 10.6 s vs 34.0 ± 6.5 s, P = 0.860), or tracheal intubation (58.2 ± 31.1 s vs 53.9 ± 25.4 s, P = 0.448). Adverse event rates, including intubation responses, were significantly lower in the ciprofol group as compared to the propofol group(20% vs 48.33%, P = 0.0019). Ciprofol was associated with reduced injection pain relative to propofol (16.7% vs 58.3%, P < 0.001).

Conclusions

Ciprofol exhibits comparable efficacy to that of propofol when used for the induction of general anesthesia in individuals undergoing gynecological surgery and is associated with fewer adverse events.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01782-7.

Pretreatment with Low-Dose Esketamine for Reduction of Propofol Injection Pain: A Randomized Controlled Trial

Background

Propofol-induced injection pain is a common adverse effect during the induction of general anesthesia. The purpose of this study is to investigate the effect of low-dose esketamine in preventing propofol injection pain.

Methods

In this double-blind, randomized, controlled trial, patients scheduled for elective ear surgery under general anesthesia received either normal saline (NS), or 40 mg lidocaine, or 0.15 mg/kg esketamine 30 seconds before manual injection of propofol. The primary outcome of this study was the incidence of propofol injection pain. The secondary outcomes included injection pain score, vital signs, total dosage of vasoactive drugs used within 5 minutes after induction, and adverse events related to drugs.

Results

A total of 105 patients were included. Compared with the NS group (67%), pretreatment with esketamine and lidocaine significantly reduced the incidence of injection pain to 29% and 33%, respectively (both P < 0.05); however, no significant difference was found between the esketamine and lidocaine groups. The median of injection pain score was significantly lower in the esketamine and lidocaine groups (both median (interquartile range) = 0 (0–1)) than that in the NS group (1 (0–2); P < 0.05). In addition, compared with the NS and lidocaine groups, preinjection esketamine provided more stable hemodynamic parameters within 5 minutes after induction (P < 0.05). No statistical difference was found in adverse events among the three groups.

Conclusions

Pretreatment with a low-dose esketamine can not only reduce the incidence of propofol injection pain but also provide a more stable circulation in patients after anesthesia induction. This convenient, well-tolerated, and economic treatment appears as an option to be routinely applied in clinic practice. Clinical Trial Registration. This trial is registered with https://www.chictr.org.cn/showproj.aspx?proj=136690 (the number for the trial registration isChiCTR2100052742).

Sedation-analgesia techniques for nonoperating room anesthesia: an update

PURPOSE OF REVIEW

There has been a substantial increase in nonoperating room anesthesia procedures over the years along with an increase in the complexity and severity of cases. These procedures pose unique challenges for anesthesia providers requiring meticulous planning and attention to detail. Advancements in the delivery of sedation and analgesia in this setting will help anesthesia providers navigate these challenges and improve patient safety and outcomes.

RECENT FINDINGS

There has been a renewed interest in the development of newer sedative and analgesic drugs and delivery systems that can safely provide anesthesia care in challenging situations and circumstances.

SUMMARY

Delivery of anesthesia care in nonoperating room locations is associated with significant challenges. The advent of sedative and analgesic drugs that can be safely used in situations where monitoring capabilities are limited in conjunction with delivery systems, that can incorporate unique patient characteristics and ensure the safe delivery of these drugs, has the potential to improve patient safety and outcomes. Further research is needed in these areas to develop newer drugs and delivery systems.

Remimazolam tosilate compared with propofol for gastrointestinal endoscopy in elderly patients: a prospective, randomized and controlled study

Background

Remimazolam tosilate (HR7056, RT), a novel ultrashort-acting benzodiazepine, can be used for procedural sedation and general anaesthesia. However, few studies have focused on the sedative effect of RT during gastrointestinal endoscopy in elderly patients. The purpose of this study is to compare the sedative effect of RT and propofol for gastrointestinal endoscopy in elderly patients.

Methods

A total of 82 patients aged ≥65 years with an American Society of Anaesthesiologists (ASA) grade I-II and a body mass index (BMI) of 18.0 to 30.0 kg/m² who were scheduled for gastrointestinal endoscopy from Jan 2021 to Aug 2021 were selected and randomly divided into a RT group and a propofol group. Alfentanil 5 μg/kg was used for analgesia in both groups. The RT group was given remimazolam tosilate 0.15 mg/kg with supplemental doses of 0.05 mg/kg as need, while the propofol group was given propofol 1.5 mg/kg with supplemental doses of 0.5 mg/kg. The supplemental doses were determined by the modified observational alertness/sedation assessment (MOAA/S) score and the patients’ body movements. Sedative effects, such as the time to loss of consciousness (LOC) (MOAA/S score ≤ 1), successful sedation in one dose, number of supplemental doses after successful induction, and recovery time, were evaluated. Sedation-related side effects, such as injection pain, haemodynamic events and respiratory depression, were also noted. Postoperative nausea and vomiting (PONV), visual analogue scale (VAS) scores at rest, remedial analgesics, and dizziness or headache were recorded. In addition, patients’ satisfaction and physician’s satisfaction of the procedure were compared between the two groups.

Results

Data from 77 patients were analysed. The success rate of sedation in both groups was 100%. The time to LOC (MOAA/S score ≤ 1) in the RT group was longer than that in the propofol group (20.7 ± 6.1s vs. 13.2 ± 5.2s, P < 0.001). There were fewer patients in the RT group reporting injection pain than that in the propofol group (0/39 vs. 5/38, P = 0.025). Haemodynamic events and respiratory depression in the RT group were less frequent than those in the propofol group ((6/39 vs. 17/38, P = 0.005), (2/39 vs. 9/38, P = 0.026), respectively). The number of supplemental doses after successful induction in the RT group was greater than that in the propofol group (4/9/11/13/1/1 vs. 8/4/18/6/2/0 requiring 0, 1, 2, 3, 4 or 5 supplemental doses, P = 0.014). The characteristics of the patients enrolled, postoperative parameters of the patients, and patients’ and physician’s satisfaction of the procedure were comparable in the two groups.

Conclusions

Compared with propofol, RT can be safely and effectively used for gastrointestinal endoscopy sedation in elderly patients, and the incidence of sedation-related adverse reactions, especially haemodynamic events and respiratory depression, is lower. When RT is used, the number of supplemental doses after successful induction may increase slightly.

Trial registration

Chictr.org.cn ChiCTR2000040498. Retrospectively registered (date of registration: December 1, 2020).

A. The Valsalva Maneuver Is Not as Effective as Lidocaine for the Attenuation of Pain on Injection of Propofol: A Randomized Controlled Study

Background and objective

Lidocaine pretreatment is considered the gold standard for attenuating pain on injection of propofol. Valsalva maneuver (VM) causes baroreceptor reflex arc-induced antinociception by increasing the intrathoracic pressure. We aimed to evaluate the efficacy of VM in alleviating the pain on injection of propofol in this randomized comparative study.

Methods

A total of 90 patients were recruited for this randomized study. They were classified into two groups. Patients in group D received 5-mL 4% lidocaine in saline intravenously while the venous drainage was occluded. Then they were asked to press a rubber ball as hard as they could. Patients in group V received 5-ml saline pretreatment. They were then asked to perform VM by blowing into rubber tubing connected to a manometer and raising and holding the pressure up to 40 mmHg. The verbal response and behavioral signs were recorded with a score corresponding to no, mild, moderate, or severe pain. A t-test was performed to compare the mean of variables between the two groups. The Kolmogorov-Smirnov test was used for testing the equality of the distribution function of pain scores between the groups. Repeated measures analysis of variance (ANOVA) was performed to test the heart rate and mean arterial pressure (MAP) at different points of observation.

Results

The incidence of pain and pain scores were significantly higher among the patients in the VM group as compared to those in the lidocaine with distraction group.

Conclusions

VM performed immediately before the injection failed to attenuate the pain produced by propofol as compared to lidocaine pretreatment along with distraction.

Comparison of ciprofol (HSK3486) versus propofol for the induction of deep sedation during gastroscopy and colonoscopy procedures: A multi-centre, non-inferiority, randomized, controlled phase 3 clinical trial

Ciprofol is a propofol analogue with improved pharmacokinetic properties. A multi‐centre, non‐inferiority trial was conducted to compare the deep sedation properties of ciprofol and propofol with a non‐inferiority margin of 8% in patients undergoing gastroscopy and colonoscopy. In total, 289 patients were randomly allocated for surgery (259 colonoscopy and 30 gastroscopy) at a 1:1 ratio to be given intravenous injections of ciprofol (0.4 mg/kg) or propofol (1.5 mg/kg). The primary outcome was the success rate of colonoscopy defined as colonoscopy completion with no need for an alternative sedative or >5 ciprofol or propofol top up doses within any 15‐min time period. The success rate of colonoscopy was 100% in the ciprofol group vs. 99.2% in the propofol group (mean difference 0.8%, 95% CI: −2.2% to 4.2%). Except for the gastrointestinal lesions found during the gastroscopy and colonoscopy procedures, the occurrence rates of adverse drug reactions in the ciprofol and propofol groups were 31.3% and 62.8%, respectively (P < 0.001). Pain on injection was less common in the ciprofol group (4.9% vs. 52.4%, P < 0.001). The outcomes demonstrated that ciprofol was non‐inferior to propofol with regard to successful sedation for gastroscopy or colonoscopy procedures and no obvious important adverse events occurred.

A comparison of ondansetron and lidocaine in reducing injection pain of propofol: a randomized controlled study

Background

Direct stimulation of the afferent nerve endings in the venous endothelium is one explanation of propofol injection pain. Previous studies found that ondansetron can also block sodium channels. This effect is similar to that of lidocaine.

Objective

The primary outcome was the efficacy of ondansetron compared to lidocaine and placebo for the reduction of propofol injection pain.

Method

This trial was conducted in 240 patients, American Society of Anesthesiologists classification I-III and aged between 18–65 years old, undergoing elective surgery, and having a 20-gauge intravenous catheter at the hand dorsum. Each group of 80 patients received 8 mg. of ondansetron in the O Group, 40 mg. of lidocaine in the L Group and normal saline in the C Group. The study medications were blindly administered to the patients through a 20-gauge intravenous catheter placed on the hand dorsum, and then 1 min later, the small dose of propofol (50 mg.) was infused via the syringe pump at a rate of 600 ml/hr. for 30 s. Following that, the syringe pump of propofol was temporarily stopped, and the patients were asked to rate their pain at the injection site.

Result

The incidence of pain was lowest in the L group (66.2%) compared with the O (82.5%) and the C groups (85.0%) (P < 0.01). The median pain score in the L, O, and C groups were 2 (0–4), 4 (2–5), and 4.5 (2–6), respectively (P < 0.01). The incidences of no pain, mild, moderate, and severe pain were also significantly different in the L group (33.8%, 37.5%, 21.2%, and 7.5%, respectively) compared with those in the O group (17.5%, 31.2%, 31.2%, and 20.0%, respectively) and the C groups (15.0%, 22.5%, 40.0%, and 22.5%, respectively) (P < 0.01).

Conclusion

Pretreatment with intravenous lidocaine, rather than ondansetron, can reduce the incidence and intensity of propofol-induced pain.

Clinical Study on the Combination of Transcutaneous Electrical Acupoint Stimulation and Lidocaine for Preventing Propofol Injection Pain

Purpose

Propofol is a widely used intravenous anesthetic in clinical practice. Lidocaine pretreatment is currently the most commonly used method to reduce the pain of propofol injection. However, propofol injection pain has not been eliminated and its incidence remains high. Transcutaneous electrical acupoint stimulation is a green therapy that combines transcutaneous electrical nerve stimulation therapy with the traditional acupuncture therapy of our motherland. This study investigated the effectiveness of transcutaneous electrical acupoint stimulation (TEAS) combined with lidocaine in preventing propofol injection pain and determined whether it can reduce postoperative complications and promote rapid postoperative recovery of patients.

Patients and Methods

A total of 220 women scheduled to undergo hysteroscopic surgery were enrolled in the study. The included patients were randomly divided into four groups of 55 patients each: normal saline group (group K), lidocaine group (group L), TEAS group (group T), and lidocaine + TEAS group (group L + T). Patients in group K received 2 mL saline (0.9% NaCl) pre-injection before anesthesia induction. Group L received 40 mg lidocaine pre-injection (2 mL of 2% lidocaine) before anesthesia induction. Group T received 30 min of transcutaneous electrical stimulation at bilateral election Hegu, Neiguan, and 2 mL saline pre-injections before anesthesia induction. Group L + T received TEAS and lidocaine pre-injection.

Results

The VAS scores and the four-point verbal rating scale of propofol injection were significantly different among the four groups. The prevalence of nausea, vomiting, abdominal pain, and abdominal distension after surgery among the four groups were statistically different. The bleeding days after surgery were significantly different among the four groups.

Conclusion

TEAS combined with lidocaine pre-injection reduced the incidence of propofol injection pain and significantly reduced patients’ pain levels compared with single lidocaine pre-injection. TEAS can also reduce the incidence of postoperative nausea and vomiting, abdominal pain, and abdominal distension, shorten postoperative bleeding days, and accelerate the postoperative recovery of patients.

Effect of 6% hydroxyethyl starch pre-administration for reduction of pain on propofol injection: A placebo-controlled randomised study

Background and Aims:

Colloids modify the vascular endothelium and prevent contact activation of various substances. Pre-administration of colloids may prevent contact activation of vascular endothelium by propofol. The objective of this study was to evaluate the effect of 6% hydroxyethyl starch (HES) 130/0.4 pre-administration on propofol injection pain.

Methods:

Adult patients of the American Society of Anesthesiologists physical status I and II patients, 18-65 years old, of either gender and undergoing elective surgery were randomised into two groups. 100 mL bolus of HES or 0.9% normal saline (NS) was administered over three to five minutes through an 18 G cannula placed in the hand or forearm vein, followed by induction with 1% propofol premixed with 2% lidocaine. Pain during propofol injection was assessed every 10 seconds before the loss of verbal contact as 0- no pain; 1- mild pain evident only on questioning after 10 seconds without any obvious discomfort; 2-moderate pain self-reported by patients within 10 seconds with some discomfort; and 3- severe pain accompanied by withdrawing of hand, and behavioural signs.

Results:

126 patients completed the study. Overall incidence of pain was significantly higher in the NS group vs HES group (53% vs 28%; P = 0.004; relative risk 1.54, 95% confidence interval 1.13-2.09). Incidence of severe (8% vs 0%) and moderate pain (16% vs 5%) was higher in the NS group, while the incidence of mild pain was comparable (29% vs 23%; NS vs HES). A significant difference was seen in the severity of pain between the groups (P = 0.002).

Conclusion:

Pre-administration of 100 mL bolus of 6% HES 130/0.4 significantly reduced propofol injection pain.

Sedation Effects Produced by a Ciprofol Initial Infusion or Bolus Dose Followed by Continuous Maintenance Infusion in Healthy Subjects: A Phase 1 Trial

Introduction

The effects of continuous infusions of ciprofol on its pharmacodynamic and pharmacokinetic properties and safety profiles in healthy Chinese subjects were evaluated.

Methods

In this open-label, randomized, two-way cross-over study, subjects received initial doses of continuous ciprofol/propofol as an infusion for 30 min in part 1 (n = 8) and a bolus dose in part 2 (n = 8) followed by maintenance infusions for a total of 4 h in part 1 and 12 h in part 2. Each subject participated in both parts with a washout time of at least 40 h.

Results

The safety and tolerability parameters of ciprofol were similar to those of propofol, and all treatment-emergent adverse events were mild. The incidences of injection pain and respiratory depression in subjects given ciprofol were lower than those receiving propofol. The pharmacokinetic parameters C_max, t_max, t_1/2, λz and MRT for ciprofol and propofol were similar, while CL, V_d and V_ss were statistically significantly different. Pharmacodynamic parameters including the Richmond Agitation Sedation Scale and bispectral index profiles of ciprofol were similar to those of propofol.

Conclusion

Ciprofol has potential for clinical application for continuous intravenous infusion to maintain sedation for 12 h with the same safety, tolerability and efficacy as propofol.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01914-4.

Efficacy and Safety of Fospropofol Disodium for Injection in General Anesthesia Induction for Adult Patients: A Phase 3 Trial

Background: Fospropofol disodium for injection (Fospropofol_FD) is a prodrug that is metabolized into propofol to produce a general anesthesia effect when administered intravenously.

Objective: This study aimed to assess the efficacy and safety of Fospropofol_FD in comparison with propofol medium/long-chain fat emulsion injections (propofol-MCT/LCT) for general anesthesia induction in adult patients undergoing elective surgeries.

Setting: Nine academic medical centers in China.

Method: This multicenter, randomized, double-blind, double-simulated, controlled, and non-inferiority trial evaluated 540 eligible adult patients randomly assigned (2:1) to the intervention (20 mg/kg Fospropofol_FD) or control (2 mg/kg propofol-MCT/LCT) groups.

Main Outcome Measure: The primary efficacy endpoint was the success rate, defined as a Modified Observer’s Assessment of Alertness/Sedation Scale score of 1 within 5 min after study drug administration. The safety endpoints consisted of adverse events (AEs) related to consciousness, cognitive function, hemodynamic status, liver and kidney function, and blood tests.

Results: A total of 347 (96.3%) and 175 (97.2%) patients in the intervention and control groups, respectively, completed the study. The success rate for the primary outcome was 97.7% for both study drugs. The most frequent AEs in the intervention group were abnormal feeling (62.0%), blood pressure reduction (13.5%), and injection site pain (13.3%). No AEs related to consciousness and mental and cognitive functions or serious adverse events were reported.

Conclusion: Fospropofol_FD (20 mg/kg) is not inferior to propofol-MCT/LCT (2 mg/kg) in general anesthesia induction for American Society of Anesthesiologists (ASA) physical status I-II adult patients undergoing elective surgeries. It is safe and effective for clinical use under anesthesiologist monitoring.

Impact on Practice Statement: Fospropofol_FD can produce a general anesthesia effect and reduce the incidence of pain at the site of injection.

Propofol Ameliorates Microglia Activation by Targeting MicroRNA-221/222-IRF2 Axis

Background

Propofol is a widely used intravenous anesthetic drug with potential neuroprotective effect in diverse diseases of neuronal injuries such as traumatic brain injury and ischemic stroke. However, the underlying molecular mechanism remains largely unknown.

Methods

Real-time qPCR, enzyme-linked immunosorbent assay, and Western blotting were used to identify the expression pattern of miR-221/222, inflammatory genes, cytokines, and IRF2. The biological roles and mechanisms of propofol in microglia activation were determined in BV2 cells and primary microglia. Bioinformatic analysis and luciferase reporter assay were used to confirm the regulatory role of miR-221/222 in Irf2 expression.

Results

We found that miR-221 and miR-222 were downstream targets of propofol and were consistently upregulated in lipopolysaccharide- (LPS-) primed BV2 cells. Gain- and loss-of-function studies revealed that miR-221 and miR-222 were profoundly implicated in microglia activation. Then, interferon regulatory factor 2 (Irf2) was identified as a direct target gene of miR-221/222. IRF2 protein levels were reduced by miR-221/222 and increased by propofol treatment. Ectopic expression of IRF2 attenuated the proinflammatory roles induced by LPS in BV2 cells. More importantly, the suppressive effects of propofol on LPS-primed activation of BV2 cells or primary mouse microglia involved the inhibition of miR-221/222-IRF2 axis.

Conclusions

Our study highlights the critical function of miR-221/222, which inhibited Irf2 translation, in the anti-inflammatory effects of propofol, and provides a new perspective for the molecular mechanism of propofol-mediated neuroprotective effect.

Pain Intensity at Injection Site during Esophagogastroduodenoscopy Using Long- and Medium-Chain versus Long-Chain Triglyceride Propofol: A Randomized Controlled Double-Blind Study

Background/Aims

The intensities of injection pain resulting from the use of long- and medium-chain triglyceride (LCT/MCT) propofol and conventional LCT propofol during esophagogastroduodenoscopy (EGD) have yet to be compared. We aimed to determine the pain intensity caused by different formulations of propofol and to evaluate the formulation that would be preferred by patients as a sedative agent during their next procedure.

Methods

This study was a single-center, randomized, controlled, and double-blind trial. Pain intensity was estimated 30 seconds after propofol injection by an examiner who was blinded to the group assignment using a numeric (0-10) pain rating scale (NPRS). After 1 week, the patients were asked whether they could recall the pain and were willing to receive the same agent for their next EGD.

Results

One hundred twenty-nine patients were randomly assigned to LCT/MCT or LCT group. Although there was no significant difference in pain incidence between the LCT/MCT and LCT groups (52.9% vs 65.6%, p=0.156), the pain intensity was significantly lower in the LCT/MCT group (NPRS median [interquartile range]; 1 (0-2) vs 2 (0-5), p=0.005). After 1 week, fewer patients in the LCT/MCT group recalled the pain (19.1% vs 63.9%, p<0.001) and more patients in the LCT/MCT group were more willing to use the same agent for their next procedure (86.8% vs 72.1%, p=0.048) than in the LCT group.

Conclusions

LCT/MCT propofol significantly reduced injection pain intensity compared to LCT propofol during EGD and preferred by patients as a sedative agent during their next EGD.

Median Effective Dose of Lidocaine for the Prevention of Pain Caused by the Injection of Propofol Formulated with Medium- and Long-Chain Triglycerides Based on Lean Body Weight

OBJECTIVE

To determine the median effective dose (ED50) of prophylactic intravenous lidocaine for the prevention of propofol medium-chain triglyceride/long-chain triglyceride (MCT/LCT) emulsion injection pain.

DESIGN

Prospective trial, Dixon up-and-down sequential method.

SETTING

Operating room of a single hospital.

PATIENTS

Thirty patients aged 18-65 years with American Society of Anesthesiologists (ASA) status I or II who were scheduled for elective surgery under general anesthesia (GA) were included.

INTERVENTIONS

The initial dose of prophylactic lidocaine before propofol MCT/LCT emulsion injection was set at 0.5 mg/kg lean body weight (LBW). The lidocaine dose was adjusted according to the degree of patients' injection pain using the Dixon up-and-down sequential method.

MEASUREMENTS

The ED50 and 95% confidence intervals (CIs) of lidocaine were calculated using the Dixon-Massey formula. Vital signs and adverse effects were recorded. In the postanesthesia care unit (PACU), patients were asked if they recalled feeling any injection pain with visual analog scale (VAS) evaluation.

RESULTS

The ED50 of lidocaine for the prevention of propofol MCT/LCT emulsion injection pain was 0.306 mg/kg LBW (95% CI, 0.262-0.357 mg/kg LBW). No adverse reactions to lidocaine occurred. In the PACU, 90.9% of patients who experienced injection pain recalled this pain (VAS score, 2.8±1.8).

CONCLUSIONS

Prophylactic intravenous lidocaine (0.306 mg/kg LBW) effectively prevented propofol MCT/LCT emulsion injection pain in 50% of patients scheduled for elective surgery under GA with no adverse reaction occurring.

Pharmacological control of pain during propofol injection: a systematic review and meta-analysis

OBJECTIVE

A research was performed to review the effect of pharmacological interventions to control the propofol injection pain.

METHODS

A search of databases was performed. Randomized clinical trials comparing pharmacological interventions with placebo or active compound to reduce of propofol injection pain were selected. The outcome was the frequency of pain. Data were analyzed in three subgroups according to type of control. Random effect model was used to calculate relative risk (RR) with 95% confidence intervals (CIs).

RESULTS

Fifty-two articles with 105 studies on 7315 adults were included. The incidence of pain in intervention and control group was 40.91% and 66.27%. Combination therapy with two drugs (RR = 0.29 95% CI = (0.11, 0.75)), opioids (RR = 0.39 95% CI = (0.28, 0.54)) and 5 HT3 antagonists (RR = 0.39 95% CI = (0.30, 0.50)) were the most effective interventions compared to placebo. Combination therapy was the most effective intervention compared to lidocaine as control (RR = 0.51 95% CI = (0.46, 0.55)). Opioids were the most effective intervention compared to long chain triglyceride propofol as control (RR = 0.27 95% CI = (0.15, 0.49)).

CONCLUSION

Pretreatment with two different drugs, opioids and surprisingly 5 HT3 antagonists were the most effective interventions compared to placebo. Combination therapy was the most effective versus lidocaine as control.

Intravenous Dexmedetomidine Administration Prior Anesthesia Induction With Propofol at 4°C Attenuates Propofol Injection Pain: A Double-Blind, Randomized, Placebo-Controlled Trial

Background: Propofol injection pain, despite various interventions, still occurs during the anesthesia induction and causes intense discomfort and anxiety in patients. This study aimed to explore the effect of intravenous dexmedetomidine on propofol injection pain prior to anesthesia induction with propofol at 4°C.

Methods: A total of 251 patients (American Society of Anesthesiologists I–II) who underwent oral and maxillofacial surgery were randomly assigned to a combination group (n = 63), lidocaine group (n = 62), dexmedetomidine group (n = 63), and placebo-control group (n = 63); they received 0.5 ug/kg dexmedetomidine prior to anesthesia induction with propofol at 4°C, 40 mg lidocaine, 0.5 ug/kg dexmedetomidine prior to anesthesia induction, and normal saline, respectively. Incidence of pain, pain intensity, and reaction to the pain stimulus were evaluated by using verbal categorial scoring (VCS), a numerical rating scale (NRS), and the Surgical Pleth Index (SPI), respectively. In addition, hemodynamic parameters such as heart rate (HR) and mean arterial pressure (MAP) were also measured. The VCS and NRS were evaluated at 5 s after propofol injection. In addition, SPI, HR, and MAP were evaluated at three time points (before anesthesia induction and 5 and 30 s after propofol injection).

Results: The incidence of pain in the combination group (51%) was significantly lower than that in the lidocaine group (71%), dexmedetomidine group (67%), or placebo-control group (94%) (p < 0.001). VCS and NRS scores in the combination group were also lower compared with the other three groups (p < 0.001), with no statistically significant differences between the lidocaine group and dexmedetomidine group (p > 0.05). The SPI of the combination group decreased significantly in comparison with the other three groups at 5 s after propofol injection (F = 96.23, p < 0.001) and 30 s after propofol injection (F = 4.46, p = 0.005). Further comparisons between HR and MAP revealed no significant differences across the groups (p > 0.05).

Conclusion: Because of the sedative nature of dexmedetomidine and analgesic effect of low temperature, this study showed that intravenous dexmedetomidine prior to anesthesia induction with propofol at 4°C is highly effective in attenuating the incidence and severity of pain during injection compared with lidocaine (40 mg), dexmedetomidine 0.5 ug/kg) and placebo. This approach was not associated with any anesthesia complications.

Clinical Trial Registration:ClinicalTrials.gov, identifier: ChiCTR-2000034663

Efficient and flexible synthesis of new photoactivatable propofol analogs

Propofol is a widely used general anesthetic, which acts by binding to and modulating several neuronal ion channels. We describe the synthesis of photoactivatable propofol analogs functionalized with an alkyne handle for bioorthogonal chemistry. Such tools are useful for detecting and isolating photolabeled proteins. We designed expedient and flexible synthetic routes to three new diazirine-based crosslinkable propofol derivatives, two of which have alkyne handles. As a proof of principle, we show that these compounds activate heterologously expressed Transient Receptor Potential Ankyrin 1 (TRPA1), a key ion channel of the pain pathway, with a similar potency as propofol in fluorescence-based functional assays. This work demonstrates that installation of the crosslinkable and clickable group on a short nonpolar spacer at the para position of propofol does not affect TRPA1 activation, supporting the utility of these chemical tools in identifying and characterizing potentially druggable binding sites in propofol-interacting proteins.

Lidocaine for Reduction of Pain Induced by Propofol in a Tertiary Care Hospital: A Descriptive Cross-sectional Study

INTRODUCTION

Propofol is the most frequently used anaesthetic agent. Despite various anaesthetic benefits, propofol is not without side effects, pain on injection being the most common adverse effect. This study aimed to find the grade of pain reduced due to the injection of propofol after administration of lidocaine.

METHODS

A descriptive cross-sectional study was conducted from March 2015 to August 2015 in the operating theatre in a tertiary care hospital after taking ethical clearance with an ethical clearance from the Institutional Review Committee. A total of 64 participants fulfilling all inclusion criteria of both gender, age ranged from 16-65 years of American Society of Anesthesiologists physical status I and II ready for elective surgery under general anaesthesia with propofol pretreated with 60mg lidocaine with venous occlusion for one minute were observed. The pain was graded by the four-point scale (0=none, 1=mild, 2=moderate, 3=severe). Haemodynamic variables were measured until just before intubation.

RESULTS

In patients pretreated with lidocaine, no pain 56 (87.5%), mild pain 8 (12.5%) and moderate pain 0 (0%) were observed.

CONCLUSIONS

The grade of pain during injection of propofol was reduced in more than three-fourth of the patients after administration of pre-anaesthetic drug-like lidocaine.

Comparison of the influence of low dose etomidate and propofol as priming dose on the incidence of etomidate induced myoclonus: a randomised, double-blind clinical trial

Background

Though hemodynamically stable, etomidate is known for its myoclonus side effect following induction. The main aim of this study is an effective attempt to decrease the incidence of myoclonus with a priming agent.

Methods

A prospective, double-blind study was carried out on 50 adults posted for elective surgery. After premedication, priming was done with etomidate 0.03 mg.kg^-1 (Group E) and propofol 0.2 mg.kg^-1 (Group P), i.e., 1/10th of induction dose. After 60 seconds of priming, patients were induced with etomidate by titrating dose over 60 seconds until loss of verbal command and eyelash reflex. The grading of myoclonus, induction dosage, and hemodynamics for 10 minutes post induction were recorded.

Results

In the study, only 4 cases had myoclonus. Grade 1 myoclonus was encountered in three cases of etomidate group, while only one case in the propofol group had grade 2 myoclonus which was not statistically significant (p-value: 0.12). There was a significant reduction in the etomidate induction dosage in both groups.

Conclusion

Priming with etomidate and propofol is equally effective in reducing myoclonus with the added benefit of hemodynamic stability and reduction of an induction dose of etomidate (> 50%).

A Co-Induction Technique Utilizing 4% Sevoflurane Followed by 0.75 mg/kg Propofol in Elderly Patients Undergoing Minimally Invasive Procedures: A Prospective Randomized Control Study

Background and Objectives: Elderly patients constitute a large segment of healthcare receivers. Considering the functional deterioration of multiple organ systems with aging, achieving a safe perioperative approach is challenging. Our aim is to study the safety and effectiveness of a genuinely regimented co-induction technique in order to minimize anesthesia-related complications. Materials and Methods: One hundred and five patients were assigned to three groups according to the induction technique: propofol, sevoflurane and co-induction group. Inclusion criteria: patients with age ≥65 and American Society of Anesthesiologists physical status classification (ASA) II-III who underwent endoscopic urological procedures. The propofol group received a dose of 1.5 mg kg⁻¹ of propofol over two minutes for induction. The sevoflurane group received 8% of sevoflurane and 100% oxygen through a plastic facemask with the fresh gas flow set at 8 L min⁻¹. The co-induction group received 4% sevoflurane through plastic facemask for two minutes, followed by a 0.75 mg kg⁻¹ dose of propofol. After ensuring full range jaw relaxation, the laryngeal mask airway (LMA) was inserted. Results: Overall, the co-induction technique had a favorable profile in terms of respiratory adverse events, while the sevoflurane group had a favorable profile in terms of hemodynamic stability. Furthermore, 24 (68.6%) patients receiving inhalational sevoflurane had episodes of transient apnea, which constitutes 77.4% of the 31 episodes of transient apnea in the studied sample (p < 0.001). Moreover, six (17.1%) patients in the sevoflurane group had an episode of partial laryngospasm (p = 0.034). Compared with the co-induction group, we found that the propofol group had significantly less systolic and diastolic blood pressures in the second minute, with p values of (0.018) and (0.015), respectively. Conclusions: The co-induction technique utilizing 4% sevoflurane at 8 L min⁻¹ flow of oxygen inhaled over two minutes followed by 0.75 mg kg⁻¹ of propofol achieved less respiratory adverse events compared with the sevoflurane group, and less hemodynamic instability compared with the propofol group.