The comparison of the effect of non-pharmacological pain relief and pharmacological analgesia with remifentanil on fear of childbirth and postpartum depression: a randomized controlled clinical trial

INTRODUCTION

Childbirth may be associated with psychological, social, and emotional effects and provide the background for women's health or illness throughout their life. This research aimed at comparing the impact of non-pharmacological pain relief and pharmacological analgesia with remifentanil on childbirth fear and postpartum depression.

MATERIALS AND METHOD

This randomized clinical trial with two parallel arms was conducted on 66 women with term pregnancy referred to Taleghani Hospital in Tabriz for vaginal delivery during September 2022 to September 2023. First, all of the eligible participants were selected through Convenience Sampling. Then, they were randomly assigned into two groups of pharmacological analgesia with remifentanil and non-pharmacological analgesia with a ratio of 1:1 using stratified block randomization based on the number of births. Before the intervention, fear of childbirth (FOC) was measured using Delivery Fear Scale (DFS) between 4 and 6 cm cervical dilatation. Pain and fear during labor in dilatation of 8 cm were measured in both groups using VAS and DFS. After delivery, FOC was assessed using Delivery Fear Scale (W DEQ Version B) and postpartum depression using the Edinburgh's postpartum depression scale (EPDS). Significance level was considered 0.05. Mean difference (MD) was compared with Independent T-test and ANCOVA pre and post intervention.

RESULTS

The mean score of FOC in the non-pharmacological analgesia group was significantly lower than that in the pharmacological analgesia group after the intervention by controlling the effect of the baseline score (MD: -6.33, 95%, Confidence Interval (CI): -12.79 to -0.12, p = 0.04). In the postpartum period, the mean score of FOC in the non-pharmacological analgesia group was significantly lower than that in the pharmacological analgesia group after controlling the effect of the baseline score (MD: -21.89; 95% CI: -35.12 to -8.66; p = 0.002). The mean score of postpartum depression in the non-pharmacological analgesia group was significantly lower than that in the pharmacological analgesia group (MD: -1.93, 95% CI: -3.48 to -0.37, p = 0.01).

TRIAL REGISTRATION

Iranian Registry of Clinical Trials (IRCT): IRCT20170506033834N10. Date of registration: 05/07/2022 Date of first registration: 05/07/2022. URL: https://www.irct.ir/trial/61030; Date of recruitment start date05/07/2022.

CONCLUSION

The study results indicated a reduction in FOC and postpartum depression among parturient women receiving non-pharmacological strategies with active participation in childbirth compared to women receiving pharmacological analgesia. Owing to the possible side effects of pharmacological methods for mother and fetus, non-pharmacological strategies with active participation of the mother in childbirth are recommended to reduce the FOC and postpartum depression.

Application of propofol-remifentanil intravenous general anesthesia combined with regional block in pediatric ophthalmic surgery

OBJECTIVE

The aim of this study is to observe the anesthetic effect and safety of intravenous anesthesia without muscle relaxant with propofol-remifentanil combined with regional block under laryngeal mask airway in pediatric ophthalmologic surgery.

METHODS

A total of 90 undergoing ophthalmic surgery were anesthetized with general anesthesia using the laryngeal mask airway without muscle relaxant. They were randomly divided into two groups: 45 children who received propofol-remifentanil intravenous anesthesia combined with regional block (LG group), and 45 children who received total intravenous anesthesia (G group). The peri-operative circulatory indicators, awakening time after general anesthesia, postoperative analgesic effect and the incidence of anesthesia-related adverse events were respectively compared between the two groups.

RESULTS

All the children successfully underwent the surgical procedure. The awakening time after general anesthesia and removal time of laryngeal mask were significantly shorter in the LG group than in the G group (P < 0.05). There was no statistically significant difference in the heart rates in the perioperative period between the two groups (P > 0.05). There was no statistically significant difference in the incidence of intraoperative physical response, respiratory depression, postoperative nausea and vomiting (PONV) and emergence agitation (EA) between the two groups (P > 0.05). The pain score at the postoperative hour 2 was lower in the LG group than in the G group (P < 0.05).

CONCLUSION

Propofol-remifentanil intravenous anesthesia combined with long-acting local anesthetic regional block anesthesia, combined with laryngeal mask ventilation technology without muscle relaxants, can be safely used in pediatric eye surgery to achieve rapid and smooth recovery from general anesthesia and better postoperative analgesia. This anesthesia scheme can improve the comfort and safety of children in perioperative period, and has a certain clinical popularization value.

Fascia Iliaca Block Reduces Remifentanil Requirement in Conscious Sedation for Transcatheter Aortic Valve Implantation - A Randomized Clinical Trial

BACKGROUND

Whether nerve block improves the quality of conscious sedation (CS) in patients undergoing transcatheter aortic valve implantation (TAVI) is unclear. This study investigated whether fascia iliaca block (FIB) reduced the remifentanil requirement and relieved pain in CS for TAVI.Methods and Results: This prospective study randomized 72 patients scheduled for elective TAVI under CS into 2 groups, with (FIB) and without (control) FIB (n=36 in each group). The sedation targeted a Bispectral Index <90 with a Richmond Agitation-Sedation Scale of -2 to -1. Dexmedetomidine (0.7 µg/kg, i.v.) combined with remifentanil (0.03 µg/kg/min, i.v.) and propofol (0.3 mg/kg/h, i.v.) was used to commence sedation. FIB using 30 mL of 0.185% ropivacaine was implemented 2 min before TAVI. Patient sedation was maintained with dexmedetomidine (0.4 µg/kg/h, i.v.) supplemented with remifentanil (0-0.02 µg/kg/min, i.v.). Remifentanil (20 µg, i.v.) was used as a rescue dose for intraprocedural pain. Compared with the control group, FIB reduced the both the total (median [interquartile range] 83.0 [65.0-98.0] vs. 34.5 [26.0/45.8)] µg; P<0.001) and continuous (25.3 [20.9/31.5] vs. 9.5 [6.8/12.5] ng/kg/min; P<0.001) doses of remifentanil administered.

CONCLUSIONS

FIB reduced the remifentanil requirement and relieved pain in patients undergoing TAVI with CS. Therefore, FIB improved the quality of CS in TAVI.

The effect of dexmedetomidine, remifentanil and metoral in reducing patient bleeding during rhinoplasty surgery

INTRODUCTION

Rhinoplasty is one of the most common surgeries in the ENT department. Rhinoplasty hemorrhage is one of the complications that different strategies have been used to reduce it. Reduction of bleeding reduces the risk of complications such as hemolytic and non-hemolytic reactions, acute lung damage, viral and bacterial infections, hypothermia and coagulation disorders. Therefore, the aim of this study was to compare the effect of dexmedetomidine, remifentanil and metoral in reducing patient bleeding during rhinoplasty surgery.

MATERIALS AND METHODS

This randomized, double-blind trial was performed on rhinoplasty patients. Rhinoplasty candidates who had the inclusion and exclusion criteria were divided into three groups of remifentanil, metoral and dexmedetomidine according to the random number table. Then 0.5 mg/kg/h of dexmedetomidine in the first group was administered, followed by 100-150 kg/h remifentanil in the second group and 50 mg metoral in the third group. Mean blood pressure, heart rate, mean bleeding and surgeon satisfaction were recorded in designed form. Data were analyzed by Spss-22 software.

RESULTS

The mean blood pressure of patients in remifentanil group was lower than the other two groups (P = 0.03). In all three times during surgery, recovery and overall time, the amount of bleeding in the remifentanil group was found to be less than the other two groups. Furthermore, the rate of bleeding in the dexmedetomidine group was found to be less than the metoral group (P = 0.03, P = 0.02). The surgeon's satisfaction score in the remifentanil group was higher than the other two groups. Satisfaction score was higher in dexmedetomidine group than metoral group (P = 0.03). The recovery time in the metoral group was shorter than the other two groups (P = 0.02).

CONCLUSION

Remifentanil caused a good and appropriate reduction of blood pressure in rhinoplasty surgery, causing less bleeding and higher satisfaction.

Predicting the optimal concentration of remifentanil for skull pin fixation with hemodynamic and analgesia nociception index monitoring

Inadequate antinociception during skull pin fixation may cause hemodynamic instability in intracranial surgery. The optimal concentration of remifentanil to provide adequate antinociception and stable hemodynamics during skull pin fixation under analgesia nociception index monitoring is unknown. This study is to assess the 90% effective concentration of remifentanil for skull pin fixation under hemodynamic and analgesia nociception index monitoring. Twenty-six patients were enrolled for intracranial surgery, anesthesia was induced and maintained under total intravenous anesthesia using target-controlled infusion for remifentanil and propofol under analgesia nociception index and bispectral index monitoring. Skull pin fixation was performed at different effect-site concentrations of remifentanil required for Dixon's up-and-down method with a step size of 0.5 ng/ml under bispectral index 40-60. Inadequate antinociception is defined when either ANI < 30 or > 20% in hemodynamic changes from baseline (e.g. heart rate > 100 beats/min, or blood pressure > 180/100 mmHg) and the effect-site concentration of remifentanil is considered as failure. It is considered success as ANI > 30 and < 20% hemodynamic changes from baseline simultaneously. Seven pairs of failure/success were used for probit analysis. The 90% effective concentration of remifentanil for skull pin fixation with adequate antinociception and hemodynamic stability was 4.7 ng/ml.

Safety and efficacy of remifentanil target-controlled infusion for conscious sedation in a pregnant woman: a case report

BACKGROUND

Every year 2% of pregnant women undergo nonobstetric surgical interventions worldwide. According to the American College of Obstetricians and Gynecologists Committee on Obstetric Practice, pregnant women should never be denied the most appropriate surgical treatment, regardless of the trimester of pregnancy. However, additional attention should be paid during the first trimester since it has the highest risk of inducing teratogenic mutations; additionally, during the third trimester, due to the possibility of preterm birth and low birth weight of the newborn, great care should be paid.

CASE PRESENTATION

We present the case of a Caucasian 36-year-old woman during her 21st week of pregnancy, with a normal-sized fetus, according to the gestational age on ultrasound exam, and with no additional risk factors. The patient referred to an increasing nasal obstruction associated with rhinorrhea of the left nasal cavity. She also reported episodes of sleep apnea and hyposmia. The patient received a detailed otolaryngological examination, which allowed for identification of a mass within the left nasal cavity. The subsequent nasal endoscopy confirmed a grayish polypoid mass lesion with a multinodular surface occupying the entire left nasal fossa. The lesion totally obliterated the left maxillary sinus, resulting in obstruction of the anterior osteomeatal unit and ethmoidal sinusitis. She was referred for a functional endoscopic sinus surgery using analgosedation with remifentanil target-controlled infusion.

DISCUSSION AND CONCLUSION

To the very best of our knowledge, this is the first case described in English literature about the use of analgosedation with remifentanil target-controlled infusion for otolaryngology surgery, specifically in functional endoscopic sinus surgery. It could be an interesting option to avoid the use of inhaled anesthetics that could induce fetal damage, especially during the first months of pregnancy. Furthermore, patient intubation is not necessary, which avoids cases of difficult intubation or any trauma to the airways. An adequate informed consent and appropriate compliance are elements of paramount importance in tailoring the anesthetic strategy for pregnant women who need nonobstetric surgical management.

Effect of esketamine on the EC50 of remifentanil for blunting cardiovascular responses to endotracheal intubation in female patients under general anesthesia: a sequential allocation dose-finding study

BACKGROUND

This study aimed to investigate the effect of esketamine on the dose-effect relationship between remifentanil and the cardiovascular response to endotracheal intubation during target-controlled infusion (TCI) of propofol.

METHODS

Patients underwent elective gynecological laparoscopic surgery under general anesthesia with endotracheal intubation, aged 18-65 years, American Society of Anesthesiologists class I or II, 18 kg/m2 ≤ body mass index ≤ 30 kg/m2, were randomly divided into the control (group C) and esketamine groups (group E). Before anesthesia induction, group E received an intravenous injection of 0.3 mg/kg of esketamine, while group C received an equal dose of physiological saline. TCI of propofol to the effect-site concentration (EC) of 3.0 μg/mL, and then TCI of remifentanil to the effect room and intravenous injection of rocuronium 0.6 mg/kg after MOAA/S was 0. Endotracheal intubation was performed after 2 min. Dixon's modified sequential method was used, and the initial EC of remifentanil was 3.0 ng/mL. The EC of remifentanil was determined according to the intubation response of the previous patient, with an adjacent concentration gradient of 0.3 ng/mL. The EC50 and EC95 values and their 95% confidence intervals (CIs) were determined using probit regression analysis.

RESULTS

The EC50 for cardiovascular response inhibition to endotracheal intubation using remifentanil was 3.91 ng/mL (95% CI: 3.59-4.33 ng/mL) and EC95 was 4.66 ng/mL (95% CI: 4.27-6.23 ng/mL) with TCI of propofol 3.0 μg/mL. After intravenous administration of 0.3 mg/kg of esketamine, the EC50 of remifentanil was 3.56 ng/mL (95% CI: 3.22-3.99 ng/mL) and EC95 was 4.31 ng/mL (95% CI: 3.91-5.88 ng/mL).

CONCLUSIONS

Combined with TCI of propofol 3.0 μg/mL for anesthesia induction, esketamine significantly reduced the EC50 and EC95 of remifentanil to inhibit the cardiovascular response to endotracheal intubation.

TRIAL REGISTRATION

The trial was registered in the Chinese Clinical Trials Registry ( www.chictr.org.cn ; registration number: ChiCTR2200064932; date of registration:24/10/2022).

Postoperative pain after different doses of remifentanil infusion during anaesthesia: a meta-analysis

BACKGROUND

This meta-analysis aimed to explore the correlation between the different doses of remifentanil-based anaesthesia and postoperative pain in randomised trials.

METHODS

The electronic databases including PubMed, Cochrane, clinical trial registries, and Google Scholar were searched up to November 2022 for randomised controlled trials (RCTs) that assessed the dose dependent efficacy of remifentanil for postoperative pain intensity and hyperalgesia.

RESULTS

31 studies involving 2019 patients were included for analysis. Compared with the high remifentanil dose administration, patients in low doses showed less postoperative pain intensity at 1-2 h (weighted mean differences (WMD): 0.60, 95% CI, 0.05 to 1.15), 3-8 h (WMD: 0.38, 95% CI, 0.00 to 0.75), 24 h (WMD: 0.26, 95% CI, 0.04 to 0.48) and 48 h (WMD: 0.32, 95% CI, 0.09 to 0.55). Remifentanil-free regimen failed to decrease the pain score at 24 h (WMD: 0.10, 95% CI, -0.10 to 0.30) and 48 h (WMD: 0.15, 95% CI, -0.22 to 0.52) in comparison with remifentanil-based anaesthesia. After excluding trials with high heterogeneity, the dose of the remifentanil regimen was closely correlated with the postoperative pain score (P=0.03). In addition, the dose of the remifentanil regimen was not associated with the incidence of postoperative nausea and vomiting (PONV) (P=0.37).

CONCLUSIONS

Our meta-analysis reveals that the low dose of remifentanil infusion is recommendable for general anaesthesia maintenance. No evidence suggests that remifentanil-free regimen has superiority in reducing postoperative pain. Moreover, remifentanil doesn't have a dose dependent effect in initiating PONV.

TRIAL REGISTRATION

The protocol of present study was registered with PROSPERO (CRD42022378360).

Effect of Remifentanil on the Tpeak-Tend Interval During Electroconvulsive Therapy

INTRODUCTION

QT interval dispersion, which reflects the regional heterogeneity of ventricular repolarization, increases during electroconvulsive therapy (ECT). Tpeak-Tend (TpTe) is considered a new marker of the transmural dispersion of ventricular repolarization (TDR). This study aimed to evaluate the effect of remifentanil on TpTe during ECT.

METHODS

Forty-two patients who were scheduled to undergo ECT with American Society of Anesthesiologists physical status I or II randomly received 0.1 μg/kg remifentanil (group R: n = 21) or saline (group C: n = 21). After the induction of general anesthesia, we measured the TpTe, TpTe/QT, TpTe/QTc, TpTe/RR, TpTe/√RR and TpTe/3√RR every minute during ECT (QT: QT interval, QTc: corrected QT interval, RR: RR interval). Statistical analysis was performed using two-way analysis of variance (ANOVA).

RESULTS

Immediately (T0) and 1 min (T1) after electrical stimulation, the RRs (group C: T0; 654.2 ± 145.9 ms, T1; 657.3 ± 114.8 ms, group R: T0; 849.6 ± 249.3 ms, T1; 885.4 ± 213.6 ms, p < 0.05) were significantly increased, while systolic (group C: T0; 177.1 ± 35 mmHg, group R: T0; 129 ± 27.2 mmHg, p < 0.05) and diastolic blood pressures (group C: T0; 107.1 ± 22.4 mmHg, T1; 101.3 ± 23.2 mmHg, group R: T0; 75.4 ± 19.3 mmHg, T1; 80.6 ± 18.3 mmHg, p < 0.05) were significantly decreased in group R compared to group C. The TpTe/RR was significantly lower at T1 in group R compared to group C (group C: 101.5 ± 28.2, group R: 76.8 ± 21.8, p < 0.05). However, there was no significant difference in TpTe, TpTe/QT, TpTe/QTc, TpTe/√RR or TpTe/3√RR between the two groups throughout the study.

CONCLUSION

Pretreatment with remifentanil suppressed the increase of TpTe/RR after electrical stimulation. Our results imply that remifentanil may lead to a decrease in TDR during ECT.

TRIAL REGISTRATION

This trial was registered with the University Hospital Medical Information Network (registration number: UMIN000051958).

Effects of remimazolam combined with remifentanil on quality of recovery after ambulatory hysteroscopic surgery: a prospective, observational study

BACKGROUND

Remimazolam, a new benzodiazepine, is known for its quick onset of effects and recovery time. Recently, it has been licensed for general anesthesia and sedation in Korea and its use is increasing in other countries. However, less is known about its effect on postoperative recovery. We used a patient-reported outcome questionnaire to examine the effect of remimazolam on postoperative recovery.

METHODS

Patients who underwent hysteroscopy on day surgery basis were administered an induction dose of remimazolam 6 mg/kg/h followed by a maintenance dose of 1-2 mg/kg/h. After surgery, the translated Korean version of 15-item Quality of Recovery scale (QoR-15K) including post-discharge nausea and vomiting (PDNV) and/or pain, was surveyed 24 h after surgery to evaluate patient recovery.

RESULTS

Total of 38 patients were enrolled in this prospective, observational study. All patients successfully completed QoR-15K. Only one patient scored low for moderate pain and PDNV. On average, patients scored 9 and above for all QoR-15K items except for moderate pain (8.66 ± 1.68). When QoR-15K items were grouped into dimensions, all dimensions scored an average of 9 or higher on a 10-point scale. In addition, 19 out of 38 patients gave score range of 148 to 150 out of possible 150.

CONCLUSIONS

Psychometric evaluation based on postoperative QoR-15K among patients receiving remimazolam shows satisfactory patient recovery profiles without significant pain or PDNV. Considering its effectiveness and safety, remimazolam could be one of useful agents for general anesthesia of day surgery in terms of postoperative recovery.

Effects of remifentanil combined with propofol on hemodynamics and oxidative stress in patients undergoing resection of rectal carcinoma

BACKGROUND

Rectal carcinoma (RC) treatment primarily involves laparoscopic surgery, which may induce significant hemodynamic changes and weaken immune function. Certain anesthetic approaches using opioid drugs (including remifentanil and sufentanil) pose risks, such as hypotension.

AIM

To determine the effects of remifentanil combined with propofol on hemodynamics and oxidative stress in patients undergoing RC resection.

METHODS

A total of 211 patients one hundred and four patients with RC treated at the First Affiliated Hospital of Dalian Medical University between November 2018 and November 2022 were retrospectively analyzed. Among them, the remifentanil group included 45 patients receiving remifentanil with propofol anesthesia and the sufentanil group included 59 patients receiving sufentanil with propofol anesthesia. Changes in the hemodynamic index, oxidative stress index, general data, consumption of remifentanil, and use of vasoactive drugs were compared. The incidences of adverse reactions were calculated.

RESULTS

The two groups did not significantly differ in terms of operation, anesthesia, and extubation times (P > 0.05). At 1 min after intubation, the sufentanil group showed a notably higher heart rate, systolic blood pressure (SBP), diastolic blood pressure, and mean arterial pressure (MAP) compared with the remifentanil group (P < 0.05), whereas the sufentanil group showed a notably higher SBP and MAP compared with the remifentanil group at 5 min after pneumoperitoneum (P < 0.05). Thirty minutes after surgery, the remifentanil group showed significantly lower plasma cortisol, noradrenaline, and glucose levels than the sufentanil group (P < 0.001). The remifentanil group consumed significantly less remifentanil than the sufentanil group (P < 0.05), and the adoption frequency of ephedrine was lower in the remifentanil group than that in the sufentanil group (P < 0.05). The incidence of hypotension was notably higher in the sufentanil group than that in the remifentanil group (P < 0.05).

CONCLUSION

Remifentanil combined with propofol can improve hemodynamics and relieve oxidative stress in patients undergoing RC resection.

Effect of transcutaneous electrical acupoint stimulation on remifentanil dosage during craniotomy aneurysm clipping: a prospective, randomized controlled study

BACKGROUND

Craniotomy aneurysm clipping is one of the main treatments for intracranial aneurysm (IA). Endotracheal intubation and intraoperative operation may induce dramatic hemodynamic fluctuations and increase the risk of aneurysm rupture. Intraoperative high-dose opioid use is the main measure to reduce the intraoperative stress response, but it increases the incidence of complications such as postoperative vomiting and delayed awakening. Transcutaneous electrical acupoint stimulation (TEAS) stimulates β-endorphin expression levels and reduces opioid requirements. In this study, we aimed to assess the effects of TEAS on remifentanil dosage and oxidative stress (OS) in craniotomy aneurysm clipping.

METHOD

Forty-two patients with craniotomy aneurysm clipping were randomized into two groups: the TEAS group (T group) and the sham TEAS group (S group). "Hegu" (LI4), "Neiguan" (PC6) and "Zusanli" points (ST36) were selected, and a "HANS" percutaneous acupoint electrical stimulator was used for intervention 30 min before anesthesia induction until the end of the operation. The primary outcome was intraoperative remifentanil dosage. The secondary outcomes were intraoperative propofol dosage, mean arterial pressure (MAP) and heart rate (HR) 5 min before the TEAS intervention (T0), 5 min before head holder pinning (T1), immediately after pinning (T2), 5 min before craniotomy (T3), immediately after craniotomy (T4), at craniotomy (T5), and at the end of surgery (T6), as well as serum β-endorphin levels at T1, T2 and T6 and neuron-specific enolase (NSE), S100β, superoxide dismutase (SOD) and malondialdehyde (MDA) levels at T1, T2 and 24 h after surgery (T7).

RESULTS

The dosage of remifentanil in the T group was reduced compared to that in the S group (P < 0.05). At T2, T4 and T5, the MAP and HR in the T group were lower than those in the S group (P < 0.05). At T2 and T7, the levels of NSE, S100β and MDA in group T were lower than those in group S (P < 0.05), while the SOD levels in group T were higher than those in group S (P < 0.05).

CONCLUSIONS

The use of TEAS can reduce the dosage of remifentanil and reduce hemodynamic fluctuations during craniotomy aneurysm clipping. It reduces the occurrence of OS and central nervous system damage during surgery and has a certain brain protective effect.

TRIAL REGISTRATION

ChiCTR2100052353. https://www.chictr.org.cn/about.html .

Evaluation of the effectiveness of analgesia nociception index (ANI) predictability for surgical stimuli under personal analgesic sufficiency status (PASS) measured by pre-tetanus-induced ANI: a pilot study

The Analgesia Nociception Index (ANI) is a promising monitor to evaluate the balance of nociception and anti-nociception based on heart rate variability. This prospective, interventional, monocentric pilot study aimed to verify the effectiveness of the personal analgesic sufficiency status (PASS) measured by pre-tetanus-induced ANI variation for surgical stimuli. After Ethics approval and informed consent, participants were anesthetized with sevoflurane and increased effect-site concentrations of remifentanil step by step (2, 4, 6 ng ml-1). At each concentration, a standardized tetanic stimulus was applied (5 s, 60 mA, 50 Hz) with no other noxious stimuli presented. Through all the concentrations, defined the lowest concentration when ANI ≥ 50 as the PASS after tetanic stimuli. The surgical stimulus was conducted under at least 5-min of PASS. Thirty-two participants were analyzed. ANI, systolic blood pressure (SBP), and Heart rate (HR) except the Bispectral Index (BIS) were significantly changed at 2 ng ml-1 after tetanic stimuli, only ANI and SBP were significantly altered at 4 and 6 ng ml-1. ANI could predict inadequate analgesia status (an increase in SBP or HR of more than 20% from the baseline) at 2 and 4 ng ml-1 (P = 0.044, P = 0.049, respectively), but not at 6 ng ml-1. The PASS under pre-tetanus-induced ANI identification didn't meet the analgesic needs under surgical stimuli. Further investigations are required to provide a reliable prediction of individualized analgesia by objective nociception monitors.Trial registration NCT05063461.

Remi-fent 1-A pragmatic randomised controlled study to evaluate the feasibility of using remifentanil or fentanyl as sedation adjuncts in mechanically ventilated patients

Objective

To evaluate the feasibility of conducting a prospective randomised controlled trial (pRCT) comparing remifentanil and fentanyl as adjuncts to sedate mechanically ventilated patients.

Design

Single-center, open-labelled, pRCT with blinded analysis.

Setting

Australian tertiary intensive care unit (ICU).

Participants

Consecutive adults between June 2020 and August 2021 expected to receive invasive ventilation beyond the next day and requiring opioid infusion were included. Exclusion criteria were pregnant/lactating women, intubation >12 h, or study-drug hypersensitivity.

Interventions

Open-label fentanyl and remifentanil infusions per existing ICU protocols.

Outcomes

Primary outcomes were feasibility of recruiting ≥1 patient/week and >90 % compliance, namely no other opioid infusion used during the study period. Secondary outcomes included complications, ICU-, ventilator- and hospital-free days, and mortality (ICU, hospital). Blinded intention-to-treat analysis was performed concealing the allocation group.

Results

208 patients were enrolled (mean 3.7 patients/week). Compliance was 80.6 %. More patients developed complications with fentanyl than remifentanil: bradycardia (n = 44 versus n = 21; p < 0.001); hypotension (n = 78 versus n = 53; p < 0.01); delirium (n = 28 versus n = 15; p = 0.001). No differences were seen in ICU (24.3 % versus 27.6 %,p = 0.60) and hospital mortalities (26.2 % versus 30.5 %; p = 0.50). Ventilator-free days were higher with remifentanil (p = 0.01).

Conclusions

We demonstrated the feasibility of enrolling patients for a pRCT comparing remifentanil and fentanyl as sedation adjuncts in mechanically ventilated patients. We failed to attain the study-opioid compliance target, likely because of patients with complex sedative/analgesic requirements. Secondary outcomes suggest that remifentanil may reduce mechanical ventilation duration and decrease the incidence of complications. An adequately powered multicentric phase 2 study is required to evaluate these results.

Efficacy, safety, and pharmacokinetics of MR13A11A, a generic of remifentanil, for pain management of Japanese patients in the intensive care unit: a double-blinded, fentanyl-controlled, randomized, non-inferiority phase 3 study

BACKGROUND

The aims of this study were to evaluate the efficacy, safety, and pharmacokinetics (PK) of continuous intravenous administration of remifentanil in mechanically ventilated patients in the intensive care unit (ICU).

METHODS

This was a multicenter, randomized, double-blinded, fentanyl-controlled, non-inferiority phase 3 study. Patients aged ≥ 20 years requiring 6 h to 10 days mechanical ventilation in an ICU and requiring pain relief were randomly assigned in a 1:1 ratio to receive either remifentanil (n = 98) or fentanyl (n = 98). Dose was titrated from an infusion rate of 1 mL/h (remifentanil: 0.025 µg/kg/min, fentanyl: 0.1 µg/kg/h) until the target level of analgesia (behavioral pain scale [BPS] ≤ 5 or numerical rating score [NRS] ≤ 3) was achieved by escalating the dose in 1 mL/h increasing. Administration was then adjusted to maintain the target level of analgesia until weaning from the ventilator. The primary endpoint was the proportion of patients who did not require rescue fentanyl. Safety was assessed according to standard procedures. PK of remifentanil in the arterial blood was assessed in 24 patients.

RESULTS

The proportion of patients achieving the primary endpoint in the remifentanil and fentanyl groups was 100% (92/92) and 97.8% (88/90), respectively. The difference between the groups was 2.2% (95% confidence interval, - 0.8-5.3) and non-inferiority of remifentanil to fentanyl was verified (p < 0.0001). The incidences of any adverse events in the remifentanil and fentanyl groups was 34 of 92 patients (37.0%) and 34 of 90 patients (37.8%), respectively. Adverse drug reactions was 12 in 92 patients (13.0%) and 15 in 90 patients (16.7%), respectively. In the PK analysis, blood remifentanil concentration decreased within 10 min to almost 50% of the end of administration, suggesting rapid offset of action following discontinuation of remifentanil.

CONCLUSIONS

Remifentanil can be used safely for pain management in mechanically ventilated Japanese patients in the ICU.

TRIAL REGISTRATION

Japan Registry of Clinical Trials, jRCT2080224954. Registered 20 November 2019, https://jrct.niph.go.jp/latest-detail/jRCT2080224954 .

Targeting the opioid remifentanil: Protective effects and molecular mechanisms against organ ischemia-reperfusion injury

Opioids are widely used in clinical practice by activating opioid receptors (OPRs), but their clinical application is limited by a series of side effects. Researchers have been making tremendous efforts to promote the development and application of opioids. Fortunately, recent studies have identified the additional effects of opioids in addition to anesthesia and analgesia, particularly in terms of organ protection against ischemia-reperfusion (I/R) injury, with unique advantages. I/R injury in vital organs not only leads to cell dysfunction and structural damage but also induces acute and chronic organ failure, even death. Early prevention and appropriate therapeutic targets for I/R injury are crucial for organ protection. Opioids have shown cardioprotective effects for over 20 years, especially remifentanil, a derivative of fentanyl, which is a new ultra-short-acting opioid analgesic widely used in clinical anesthesia induction and maintenance. In this review, we provide current knowledge about the physiological effects related to OPR-mediated organ protection, focusing on the protective effect and mechanism of remifentanil on I/R injury in the heart and other vital organs. Herein, we also explored the potential application of remifentanil in clinical I/R injury. These findings provide a theoretical basis for the use of remifentanil to inhibit or alleviate organ I/R injury during the perioperative period and provide insights for opioid-induced human organ protection and drug development.

Comparison of the effects of intraoperative remifentanil and sufentanil infusion on postoperative pain management in robotic gynecological surgery: a retrospective cohort study

BACKGROUND

Remifentanil and sufentanil are potent short-acting synthetic opioid analgesics. The administration of remifentanil has been associated with the incidence of opioid-induced hyperalgesia. Opioid-induced hyperalgesia may be alleviated when opioids, such as morphine, are switched to sufentanil. Therefore, this retrospective observational study aimed to compare the effects of remifentanil and sufentanil on postoperative pain in patients undergoing robotic gynecological surgery.

METHODS

We retrospectively analyzed the electronic medical records of patients who underwent elective robotic gynecological surgery between January 2016 and February 2021. The patients were classified into sufentanil (n = 159) or remifentanil (n = 359) groups according to the opioids administered continuously during anesthesia. The primary outcome assessed in this study was the postoperative pain score measured using the numeric rating scale (NRS). The secondary outcomes assessed included the recovery time (from discontinuation of opioid infusion to extubation) and frequency of rescue analgesic administration in the post-anesthesia care unit (PACU).

RESULTS

The recovery time did not differ significantly between the two groups. The NRS score for pain (median [1Q, 3Q]) in the PACU was significantly lower in the sufentanil group than in the remifentanil group (2 [2, 3] vs. 4 [3, 7], P < 0.001). The frequency of rescue analgesic administration in the PACU was 6.3% and 35.4% in the sufentanil and remifentanil groups, respectively (P < 0.001).

CONCLUSIONS

Sufentanil, as an adjunct to sevoflurane anesthesia is more advantageous than remifentanil in terms of postoperative pain control during robotic gynecological surgery.

Remimazolam Compared to Propofol for Total Intravenous Anesthesia with Remifentanil on the Recovery of Psychomotor Function: A Randomized Controlled Trial

INTRODUCTION

This study aimed to compare remimazolam to propofol in psychomotor recovery after total intravenous anesthesia (TIVA) using the Trieger dot test.

METHODS

Sixty-six patients who were scheduled to undergo endoscopic sinus surgery with American Society of Anesthesiologists (ASA) physical status I or II were randomly allocated to the remimazolam (group R) or propofol group (group P). In group R, all patients received flumazenil postoperatively. After discontinuation of anesthetic agents, the time to eye opening, response to verbal commands, extubation, and discharge from the operation room were measured. Psychomotor recovery was assessed using the Trieger dot test before induction and at 0, 30, 60, 90, 120, 150, and 180 min after anesthesia.

RESULTS

The time to eye opening, response to verbal commands, extubation, and discharge from the operation room were significantly longer in group P compared to group R (group P: 9.8 ± 3.2 min, 11.5 ± 3.4 min, 12.7 ± 3.4 min, 18.1 ± 4.2 min; group R: 6.5 ± 2 min, 7.3 ± 2.6 min, 8.4 ± 2.9 min, 13.2 ± 3.2 min; respectively, p < 0.05). In the Trieger dot test, the number of dots missed was significantly increased in group R compared to group P at 30, 60, 90, and 120 min after discharge from the operation room (group R: 20.5 ± 9.3, 16 ± 8.8, 14.9 ± 11.1, 14.3 ± 10.8; group P: 14.6 ± 7.8, 10 ± 7.1, 8.7 ± 7.3, 7.3 ± 5.7; respectively, p < 0.05). The maximum distance of dots missed was significantly increased in group R compared to group P at 30 min after discharge from the operation room (group R: 3.9 ± 2.8; group P: 2.7 ± 1.6; p < 0.05).

CONCLUSION

Our results suggest that remimazolam with flumazenil leads to rapid recovery following anesthesia; however, it may cause delayed psychomotor decline.

CLINICAL TRIAL REGISTRATION

This trial is registered with the University Hospital Medical Information Network (registration number UMIN000044900).

The Effects of Remifentanil, Dexmedetomidine, and Metoral as Adjuncts to Thiopental on Hemodynamic Status After Electroconvulsive Therapy in Patients with Major Depressive Disorder: A Randomized Controlled Clinical Trial

Background

Depression is a prevalent mental disorder affecting more than 300 million people of all ages globally. Despite being the first-line treatment for depression, antidepressant medications are only effective for 60% - 70% of patients. Electroconvulsive therapy (ECT) is an effective treatment for severe cases, although it can result in short-term side effects.

Objectives

This study aimed to compare the effectiveness of remifentanil, dexmedetomidine, and metoral as premedications for ECT in patients with major depressive disorder (MDD).

Methods

In this prospective double-blinded randomized controlled clinical trial, a total of 120 MDD patients aged 18 - 60 were included. They were randomly assigned to receive remifentanil, dexmedetomidine, or metoral in combination with thiopental before ECT. Hemodynamic responses (mean arterial blood pressure, pulse rate, arterial blood oxygen saturation), seizure duration, recovery time, agitation scores, and patient satisfaction scores (reverse coded) were measured and compared.

Results

Dexmedetomidine exhibited superior hemodynamic control with lower mean arterial blood pressure (P < 0.001) and pulse rate (P < 0.001) than remifentanil and metoral. Patients receiving dexmedetomidine or remifentanil showed reduced agitation (P < 0.001) and better satisfaction than the metoral group (P < 0.001). Remifentanil displayed intermediate outcomes, while metoral exhibited the least favorable results. Seizure duration was not significantly different between the dexmedetomidine and remifentanil groups (P = 0.843).

Conclusions

Dexmedetomidine is considered the most satisfactory group due to the better control of blood pressure, heart rate, and agitation and better patient satisfaction despite the longer recovery time.

Intra-articular remifentanil on postoperative pain in knee arthroscopic surgery; a double blind randomized clinical trial

BACKGROUND

We aimed to assess the efficacy of intra-articular remifentanil in relieving postoperative pain after knee arthroscopy.

METHODS

We conducted a double-blind randomized clinical trial study on 60 patients. Patients were divided into two equal groups. The control group received 25 ml of intra-articular normal saline, and the intervention group received 200 μg of remifentanil dissolved in 25 ml of saline. We evaluated at rest postoperative pain at 1, 3, 6, 12, 18, and 24 h after the surgery using the Visual Analog Scale (VAS). Patients with VAS scores of 4 or more received meperidine (pethidine). The first time meperidine was requested and the total amount of meperidine consumed was recorded.

RESULTS

Out of 60 patients, 49 were male (81.6%), and the mean age of participants was 32.71 (7.02) years. An hour after the surgery, the control group showed a mean VAS score of 8.66 (1.26), and decreased to 2.53 (1.67) at the end of 24 h. The intervention group started with a mean VAS score of 2.23 (1.81) and ended at 0.10 (0.305). All patients in the control group and 11 (36.7%) patients in the intervention group asked for analgesics during follow-up. The mean total meperidine dose in the control and intervention groups was 108.33 (23.97) mg and 13.33 (19.40) mg, respectively (P < 0.001; 95% confidence interval of the difference 83.72 to 106.27).

CONCLUSIONS

Intra-articular remifentanil may decrease postoperative pain and analgesic requirements in patients undergoing knee arthroscopy.

Randomized comparison of effects of two different remifentanil dose on surgical conditions during endoscopic sinus surgery

BACKGROUND

The combination of propofol and remifentanil results in better surgical field conditions during endoscopic sinus surgery than inhalation anesthesia. This study compared surgical field conditions between two groups receiving low or high concentration of remifentanil and hemodynamic variables using non-invasive cardiac monitoring.

METHODS

Fifty-four patients between ASA I or II, were randomly assigned to either the high-concentration remifentanil group (HR), effect-site concentration of 8 ng/mL or the low-concentration remifentanil group(LR), effect-site concentration of 4 ng/mL. Surgical condition was evaluated using the Boezaart Surgical Field Grading Scale presented by Boezaart. Cardiac output was measured using non-invasive cardiac monitoring (CSN-1901).

RESULTS

In terms of surgical conditions, the HR group showed significantly lower values than the LR group (p = 0.021) at 90 min after the start of surgery. Heart rate was significantly lower in the HR group than the LR group at 30, 60, and 90 min after the start of surgery (30 min; p = 0.005, 60 min; p = 0.002, 90 min; p = 0.001). There was a statistically significant decrease of cardiac output in the HR group compared to the LR group immediately after endotracheal intubation and at 30, 60, and 90 min after the start of surgery (Base; P = 0.222, Intubation; P = 0.016, 30 min; p = 0.014, 60 min; P = 0.012, 90 min; P = 0.008). However, in the case of stroke volume, there was no significant difference between the two groups in all measurements.

CONCLUSION

When comparing the HR group and the LR group, the surgical condition was improved at 90 min after the start of surgery. MAP was lower in the HR group and this was a result of reduction in cardiac output primarily attributed to the decrease in heart rate rather than a decrease in stroke volume.

TRIAL REGISTRATION

Clinical Trial Registry of the Republic of Korea (KCT0006453).

Effect-site concentrations of remifentanil for smooth emergence from combined epidural-general anesthesia or general anesthesia in patients using video double-lumen tube: A randomized trial

Objective

The present study aimed to determine the effect-site concentration of remifentanil of 90% (EC90) for smooth emergence in patients with a video DLT (VDLT) under sevoflurane-maintained general anesthesia and to investigate whether the EC90 was affected by epidural anesthesia.

Methods

One hundred and twenty patients who underwent video-assisted thoracic surgery (VATS) were enrolled. Patients received either general anesthesia combined with epidural anesthesia (PEA group, n = 60) or general anesthesia (GA group, n = 60). The primary outcome was the EC90 for smooth emergence in both groups. The secondary outcomes were intraoperative emergence, smooth emergence, recovery, and hemodynamic profiles in both groups.

Result

The EC90 values for smooth emergence in patients using VDLT were 3.5 ng/ml (95% confidence interval [CI], 3.3-4.4 ng/ml) in the PEA group and 2.7 ng/ml (95% CI, 2.5-3.2 ng/ml) in the GA group. The total amount of remifentanil infusion during emergency was significantly higher in the PEA group (164.6 ± 47.9 μg) than in the GA group (127.1 ± 30.4 μg) (P < 0.001). The number of patients who experienced hypotension during emergency in the PEA group was higher than that in the GA group (46.7% versus 13.3%, P < 0.001).

Conclusion

The EC90 of remifentanil for smooth emergence in patients with VDLT under general anesthesia combined with epidural anesthesia (3.5 ng/ml) was higher than that under general anesthesia (2.7 ng/ml).

Trial registration

Chinese Clinical Trial Registry, ChiCTR2100054230.

A Comparative Study of the Effect of Labetalol and Remifentanil on Pain Control After Bariatric Surgery

Background

Finding the optimal combination of anesthetics to maintain hemodynamic stability during surgery can be challenging. Traditionally, strong opioid analgesics such as fentanyl and its newer analogs have been used. However, the use of narcotics is associated with certain side effects.

Objectives

This study compares the effects of labetalol and remifentanil in pain control after bariatric surgery in Hazrat Rasool Akram Hospital.

Methods

This randomized, double-blind clinical trial was conducted on 48 laparoscopic bariatric surgery patients. The participants were randomly divided into two groups receiving remifentanil or labetalol. Postoperative pain was measured in the recovery unit using the numerical rating scale (NRS). This score was recorded upon entering recovery, and 30 minutes, 60 minutes, and 120 minutes after surgery for each patient. Also, the duration of anesthesia, the duration of the operation, the recovery time, the dose of the administered opioids, the volume of intravenous fluids, and the dose of administered propofol were recorded for each patient. Nausea and vomiting after the operation were also recorded as outcomes.

Results

There were no significant differences between the two groups regarding the mean duration of surgery and anesthesia, dose of the administered anesthetics, recovery period, nausea and vomiting, and the dose of analgesics after the operation. The mean pain intensity during the given period and also the trend of pain intensity changes between the two groups demonstrated no statistically significant differences (P = 0.112). During the operation, 9 subjects (37.5%) in the labetalol group and 16 (66.7%) in the remifentanil group needed more analgesics (rescue drug); in this regard, a significant difference was observed between the two groups (P = 0.043).

Conclusions

Based on the study's findings, there were no significant differences between labetalol and remifentanil in post and perioperative pain control. However, rescue drugs needed to maintain hemodynamic stability during laparoscopic surgery were significantly lower in patients who received labetalol than remifentanil. Postoperative complications were also comparable between labetalol and remifentanil.

Effects of Pharmacological Intervention on Recovery After Sevoflurane Anesthesia in Children: a Network Meta-analysis of Randomized Controlled Trials

Sevoflurane, commonly administered to children as anesthesia, often leads to emergence delirium (ED). Currently, a consensus is lacking among clinicians regarding pharmacological interventions to improve recovery. To determine an effective approach, we compared the effects of several drugs in lowering the incidence of ED after sevoflurane anesthesia in children.We searched online databases for relevant randomized controlled trials (59 studies selected; 5199 NMA-eligible participants) and performed a frequentist network meta-analysis (NMA). This study was registered on PROSPERO (number CRD: 42022329939).All included studies had a low to moderate risk of overall bias. The incidence of ED after sevoflurane anesthesia in children differed according to other drugs administered, and were ranked from high to low according to the surface under the cumulative ranking curve (SUCRA).Sufentanil (91.2%) and dexmedetomidine (77.6%) were more likely to reduce the incidence (SUCRA value) of ED, whereas the placebo (6.5%), ramelteon (11.1%), and magnesium (18%) were less likely to reduce the incidence of ED. Remifentanil (89.3%) ranked first in shortening emergence time, followed by placebo (82.4%) and ketamine (69.7%). Placebo shortened extubation time, followed by remifentanil (66.5%) and alfentanil (61.4%).Sufentanil and remifentanil lowered sevoflurane-induced ED incidences among children and shortened the emergence time more effectively than other drugs. Most adjuvant drugs that are combined with sevoflurane either do not change or may even prolong extubation time. Further research and clinical trials are required to support and update these conclusions.

Managing general anesthesia for low invasive dental procedures while maintaining spontaneous respiration with low concentration remifentanil: a cross-sectional study

BACKGROUND

We assessed the relationship between patient age and remifentanil dosing rate in patients managed under general anesthesia with spontaneous breathing using low-dose remifentanil in sevoflurane.

METHODS

The participants were patients with an American Society of Anesthesiologists Physical Status of 1 or 2 maintained under general anesthesia with low-dose remifentanil in 1.5-2.0% sevoflurane. The infusion rate of remifentanil was adjusted so that the spontaneous respiratory rate was half the rate prior to the induction of anesthesia, and γH (µg/kg/min) was defined as the infusion rate of remifentanil under stable conditions where the respiratory rate was half the rate prior to the induction of anesthesia for ≥ 15 minutes. The relationship between γH and patient age was analyzed statistically by Spearman's correlation analysis.

RESULTS

During dental treatment under general anesthesia using low-dose remifentanil in sevoflurane, a significant correlation was detected between γH and patient age. The regression line of y = -0.00079 x + 0.066 (y-axis; γH, x-axis; patient's age) was provided. The values of γH provide 0.064 µg/kg/min at 2 years and 0.0186 µg/kg/min at 60 years. Therefore, as age increases, the dosing rate exhibits a declining trend. Furthermore, in the dosing rate of remifentanil when the patient's respiratory rate was reduced by half from the preanesthetic respiratory rate, the dosing rate provided was around 0.88 mL/h in all ages if the remifentanil was diluted as 0.1 mg/mL. EtCO2 showed 51.0 ± 5.7 mmHg, and SpO2 was controlled within the normal range by this method. In addition, all dental treatments were performed without major problems, such as awakening and body movement during general anesthesia, and the post-anesthetic recovery process was stable.

CONCLUSION

General anesthesia with spontaneous breathing provides various advantages, and the present method is appropriate for minimally invasive procedures.

Remifentanil Anesthesia in Elderly Patients Undergoing Curative Resection for Hepatocellular Carcinoma

INTRODUCTION

The aim of this work is to evaluate the clinical efficacy and safety of sufentanil vs. remifentanil anesthesia in elderly patients undergoing curative resection for hepatocellular carcinoma (HCC).

METHODS

Medical records of elderly patients aged ≥ 65 years who received curative resection for HCC between January 2017 and December 2020 were retrospectively reviewed. The patients were divided into either the sufentanil group or the remifentanil group according to the method of analgesia used. Vital signs including mean arterial pressure (MAP), heart rate (HR), and arterial oxygen saturation (SpO2), distribution of T-cell subsets (CD3, CD4, and CD8 lymphocytes), distribution of the stress response index [cortisol (COR), interleukin (IL)-6, C-reactive protein (CRP), and glucose (GLU)] were recorded prior to anesthesia (T0), after induction of anesthesia (T1), at the end of surgery (T2), 24 h after surgery (T3), and 72 h after surgery (T4). Postoperative adverse events were collected.

RESULTS

Repeated measure analysis of variance (ANOVA) showed that after controlling for baseline patient demographic and treatment characteristics as covariates, both between- and within-group effects were significant (all P < 0.01), and the interaction between time and treatments was also significant (all P < 0.01) in the vital signs (MAP, HR, and SpO2), distribution of T-cell subsets (CD3, CD4, and CD8 lymphocytes), and distribution of the stress response index (COR, IL-6, CRP, and GLU), indicating that sufentanil led to stable hemodynamic and respiratory functions, lower reduction of T-lymphocyte subsets, and stable stress response indices compared to remifentanil. There is no significant difference in adverse reactions between the two groups (P = 0.72).

CONCLUSIONS

Sufentanil was associated with improved hemodynamic and respiratory function, less stress response, less inhibition of cellular immunity, and similar adverse reactions compared with remifentanil.

Comparison of remifentanil and esketamine in combination with propofol for patient sedation during fiberoptic bronchoscopy

BACKGROUND

Ideal sedation and analgesia strategies for fiberoptic bronchoscopy have not been found. At present, propofol based sedation strategy still has some defects, such as respiratory depression and blood pressure drop. It is difficult to meet the requirements of safety and effectiveness at the same time. The aim of this study was to compare the clinical efficacy of propofol/remifentanil with propofol/esketamine for patient sedation during fiberoptic bronchoscopy.

METHOD

Patients undergoing fiberoptic bronchoscopy were randomly assigned to propofol/ remifentanil (PR group; n = 42) or propofol/esketamine (PK group; n = 42) for sedation and analgesia. The primary outcome was the rate of transient hypoxia (oxygen saturation (SpO₂) < 95%). The secondary outcomes are the intraoperative hemodynamics, including the changes in blood pressure, heart rate, the incidence of adverse reactions, the total amount of propofol usage were recorded, and the satisfaction level of patients and bronchoscopists.

RESULTS

After sedation, the arterial pressure and heart rate of patients in the PK group were stable without significant decrease. Decreases in diastolic blood pressure, mean arterial pressure, and heart rate were observed in patients in the PR group (P < 0.05), although it was not of clinical relevance. The dosage of propofol in the PR group was significantly higher than that in the PK group (144 ± 38 mg vs. 125 ± 35 mg, P = 0.012). Patients in the PR group showed more transient hypoxia (SpO₂ < 95%) during surgery (7 vs. 0, 0% versus 16.6%, P = 0.018), more intraoperative choking (28 vs. 7, P < 0.01), postoperative vomiting (22 vs. 13, P = 0.076) and vertigo (15 vs. 13, P = 0.003). Bronchoscopists in the PK group showed more satisfaction.

CONCLUSION

Compared with remifentanil, the combination of esketamine with propofol in fiberoptic bronchoscopy leaded to more stable intraoperative hemodynamics, lower dosage of propofol, lower transient hypoxia rate, fewer incidence of adverse events, and greater bronchoscopists satisfaction.

Comparison of remimazolam-remifentanil and propofol-remifentanil during laparoscopic cholecystectomy

BACKGROUND

Remimazolam is a novel benzodiazepine with fast onset and short half-life. We compared the effects of remimazolam and propofol on recovery profiles for general anesthesia in patients undergoing laparoscopic cholecystectomy.

METHODS

We randomly assigned 108 patients to either a remimazolam (n=54) or propofol (n=54) group. Remimazolam and propofol were used for induction and maintanance of anesthesia. Following anesthesia, we recorded the time until an Aldrete score of 9 was achieved as the primary surrogate marker of complete recovery. The time to reach a Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score of 2 and the time from the end of anesthesia to eye opening time, recovery time of orientation, time to spontaneous breathing, extubation time, and the time required for analgesics were measured. Heart rate, blood pressure, and bispectral index were assessed before, during, and after pneumoperitoneum.

RESULTS

We included 101 patients in the analysis. In the remimazolam group, it took longer to reach an Aldrete score of 9 after the drug infusion ended (P = 0.031). There was no difference in the time to reach MOAA/S 2 between the two groups. The time to eye opening, recovery time of orientation, and time required for analgesics were longer and heart rate was higher in the remimazolam group. Neither blood pressure, nor extubation time differed between groups.

CONCLUSIONS

Remimazolam and propofol provided safe induction and maintenance of anesthesia in patients undergoing laparoscopic cholecystectomy. The recovery time from anesthesia was longer than that with propofol. Fewer hemodynamic changes were observed with remimazolam, but further studies are needed.

The effect-site concentration of remifentanil blunting endotracheal intubation responses during anesthesia induction with etomidate: a dose-finding study

BACKGROUND

Remifentanil can inhibit the hemodynamic responses caused by endotracheal intubation, but the effect-site concentration of it required to control intubation responses when combined with etomidate has not been demonstrated. The purpose of this study was to determine the effect-site concentration of remifentanil blunting tracheal intubation responses in 50% and 95% of patients (EC₅₀ and EC₉₅) during etomidate anesthesia.

METHODS

American Society of Anesthesiologists physical status (ASA) I-II elective surgical patients receiving target-controlled infusion (TCI) of remifentanil, followed by etomidate and rocuronium for anesthesia were enrolled. The Belive Drive A2 monitor was used to calculate the MGRSSI (Maygreen Sedative state index) of hypnotic effect and the MGRNOX (Maygreen Nociception index) of nociception. The MGRSSI and the MGRNOX value were generated every 1 s. Mean arterial pressure (MAP) and heart rate (HR) were measured every minute, noninvasively. Using the modified Dixon's up-and-down method, the concentration of remifentanil was determined based on the intubation response of the previous patient. The cardiovascular response during endotracheal intubation was defined as positive when MAP or HR is 20% higher than the pre-intubation value. A probit analysis was used for calculating EC₅₀, EC₉₅ and 95% confidence interval (CI).

RESULTS

The EC₅₀ and EC₉₅ of remifentanil blunting tracheal intubation responses were found to be 7.731 ng/ml (95%CI: 7.212-8.278 ng/ml) and 8.701 ng/ml (95%CI: 8.199-11.834 ng/ml). There were statistically significant increases in HR, MGRSSI and MGRNOX value to tracheal intubation in the positive responses group compared to the negative group. The most common adverse event was postoperative nausea and vomiting, which occurred in 3 patients.

CONCLUSION

Remifentanil effect-site concentration of 7.731 ng/ml is effective in blunting sympathetic responses to tracheal intubation in 50% of patients when combined with etomidate anesthesia.

TRIAL REGISTRATION

The trial was registered at the Chinese Clinical Trials Registry ( www.chictr.org.cn , registration number: ChiCTR2100054565, date of registration: 20/12/2021).

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.

The effects of the administration sequence and the type of hypnotics on the development of remifentanil-induced chest wall rigidity: a randomized controlled trial

BACKGROUND

Research on remifentanil-induced chest wall rigidity is limited. Furthermore, its incidence is unknown, and the clinical factors influencing its development remain unclear. This prospective, double-blind, randomized controlled trial aimed to investigate the effects of the administration sequence of hypnotics and remifentanil as well as the type of hypnotic administered on the development of remifentanil-induced chest wall rigidity.

METHODS

A total of 125 older patients aged [Formula: see text] 65 years, who were scheduled to undergo elective surgery under general anesthesia, were enrolled in this study. Participants were randomly assigned to one of four groups; Thio-Remi, Pro-Remi, Remi-Thio, or Remi-Pro. After confirming the loss of consciousness and achieving a target effect-site concentration of 3 ng/mL remifentanil, the development of remifentanil-induced chest wall rigidity was evaluated.

RESULTS

The incidence of chest wall rigidity was significantly higher in the remifentanil-hypnotic group than in the hypnotic-remifentanil (opposite sequence) group (55.0% vs. 21.7%, P < 0.001). Logistic regression analysis revealed that remifentanil-hypnotic administration was a significant predictor of the development of chest wall rigidity (crude odds ratio 4.42, 95% confidence interval 1.99; 9.81, P < 0.001).

CONCLUSIONS

Pretreatment with hypnotics potentially reduces the development of chest wall rigidity during the induction of balanced anesthesia with remifentanil in older patients.

TRIAL REGISTRATION

This article was registered at WHO International Clinical Trials Registry Platform (Trial number: KCT0006542).

Effective concentration of remifentanil for successful i-gel insertion during remimazolam induction

BACKGROUND

Remifentanil can be used as adjuvants during remimazolam induction without neuromuscular blockade. We evaluated the 95% effective concentration (EC) of remifentanil effect-site concentration (Ce) for the successful insertion of an i-gel using the biased-coin up-and-down method in adult patients during remimazolam induction.

METHODS

Forty 19-65 year-old patients scheduled to undergo surgery using i-gel were enrolled. Anesthesia was induced using remimazolam infusion (12 mg/kg/h). Simultaneously, remifentanil was infused at a predetermined Ce. After 5 min of anesthesia induction, the i-gel was inserted. The 95% EC (EC95) of remifentanil in each patient was determined using a biased-coin up-and-down method based on a successful insertion in a preceding patient. The step size of remifentanil Ce was 0.4 ng/ml. If the insertion failed, remifentanil Ce was increased in the next patient. Following successful insertions, the corresponding concentration decreased in subsequent patients with a probability of 1/19 or was maintained with a probability of 18/19. The time from remimazolam infusion initiation to a bispectral index (BIS) < 60 (time to BIS60) and hemodynamic variables were measured and recorded.

RESULTS

The EC95 (95% CI) of Ce was 2.07 (1.94, 2.87) ng/ml. The overall time to BIS60 was 154.0 ± 39.9 s. No patient experienced significant hypotension or bradycardia during remimazolam induction.

CONCLUSIONS

The EC95 of remifentanil Ce was 2.07 (1.94, 2.87) ng/ml for successful i-gel insertion during remimazolam induction at 12 mg/kg/h without hemodynamic instability in adult patients. Future studies should measure remifentanil Ce in elderly patients or using remimazolam at various infusion doses.

Anesthetic Management Using Remimazolam in a Hemodialysis Patient

Remimazolam, an ultra-short-acting benzodiazepine, is a new intravenous anesthetic used for sedation and general anesthesia. Because remimazolam is primarily metabolized by carboxylesterases in the liver and other tissues including the lung and has metabolites with little or no bioactivity, its anesthetic effect is not significantly influenced by renal dysfunction. Therefore, remimazolam may be considered an appropriate agent for hemodialysis patients and may have added benefits beyond midazolam and propofol. Remimazolam has also been suggested to cause less cardiac depression than propofol. This case report presents an 82-year-old female hemodialysis patient with chronic heart failure who underwent partial glossectomy for squamous cell carcinoma of the tongue under general anesthesia with remimazolam and remifentanil. Hemodynamic control was stable during the anesthetic, which was safely completed without any adverse events and resulted in a rapid, clear emergence without flumazenil. Remimazolam and remifentanil may be appropriate as first-line general anesthetic agents for hemodialysis patients with heart failure.

Comparison of the perfusion index as an index of noxious stimulation in monitored anesthesia care of propofol/remifentanil and propofol/dexmedetomidine: a prospective, randomized, case-control, observational study

BACKGROUND

Dexmedetomidine, one of the sedatives, has an analgesic effect. We aimed to investigate postoperative analgesia with dexmedetomidine as adjuvants for procedural sedation using perfusion index (PI).

METHODS

In this prospective, randomized, case-control, observational study, 72 adult patients, 19-70 years, who were scheduled for chemoport insertion under monitored anesthesia care were performed. According to the group assignment, remifentanil or dexmedetomidine was simultaneously infused with propofol. The primary outcome was PI 30 min after admission to the post anesthesia care unit (PACU). And, pain severity using numerical rating scale (NRS) score and the relationship between NRS score and PI were investigated.

RESULTS

During PACU staying, PI values were significantly different between the two groups PI values at 30 min after admission to the PACU were 1.3 (0.9-2.0) in the remifentanil group and 4.5 (2.9-6.8) in the dexmedetomidine group (median difference, 3; 95% CI, 2.1 to 4.2; P < 0.001). The NRS scores at 30 min after admission to the PACU were significantly lower in the dexmedetomidine group (P = 0.002). However, there was a weak positive correlation between NRS score and PI in the PACU (correlation coefficient, 0.188; P = 0.01).

CONCLUSION

We could not find a significant correlation between PI and NRS score for postoperative pain control. Using PI as a single indicator of pain is insufficient.

TRIAL REGISTRATION

Clinical Trial Registry of Korea, https://cris.nih.go.kr : KCT0003501, the date of registration: 13/02/2019.

Association between intraoperative remifentanil use and postoperative hyperalgesia in adolescent idiopathic scoliosis surgery: a retrospective study

BACKGROUND

The liberal use of remifentanil in spine surgery has been associated with an increased incidence of postoperative hyperalgesia. Nevertheless, controversies remain as the existing evidence is inconclusive to determine the relationship between remifentanil use and the development of opioid-induced hyperalgesia. We hypothesized that intraoperative infusion of higher dose remifentanil during scoliosis surgery is associated with postoperative hyperalgesia, manifesting clinically as greater postoperative morphine consumption and pain scores.

METHODS

Ninety-seven patients with adolescent idiopathic scoliosis (AIS) who underwent posterior spinal fusion surgery at a single tertiary institution from March 2019 until June 2020 were enrolled in this retrospective study. Anesthesia was maintained using a target-controlled infusion of remifentanil combined with volatile anesthetic desflurane in 92 patients, while five patients received it as part of total intravenous anesthesia. Intravenous ketamine, paracetamol, and fentanyl were administered as multimodal analgesia. All patients received patient-controlled analgesia (PCA) morphine postoperatively. Pain scores at rest and on movement, assessed using the numerical rating scale, and the cumulative PCA morphine consumption were collected at a six-hourly interval for up to 48 h. According to the median intraoperative remifentanil dose usage of 0.215 µg/kg/min, patients were divided into two groups: low dose and high dose group.

RESULTS

There were no significant differences in the pain score and cumulative PCA morphine consumption between the low and high dose remifentanil group. The mean duration of remifentanil infusion was 134.9 ± 22.0 and 123.4 ± 23.7 min, respectively.

CONCLUSION

Intraoperative use of remifentanil as an adjuvant in AIS patients undergoing posterior spinal fusion surgery was not associated with postoperative hyperalgesia.

Antisense oligodeoxynucleotides against dynamin-related protein 1 reduce remifentanil-induced hyperalgesia by modulating spinal N-methyl-D-aspartate receptor expression in rats

Background

Spinal N-methyl-D-aspartate (NMDA) receptor activation is attributed to remifentanil-induced hyperalgesia (RIH). However, the specific mechanism and subsequent treatment is still unknown. Previous studies have shown that the dynamin-related protein 1 (DRP1)-mitochondria-reactive oxygen species (ROS) pathway plays an important role in neuropathic pain. This study examined whether antisense oligodeoxynucleotides against DRP1 (AS-DRP1) could reverse RIH.

Methods

The authors first measured changes in paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) at 24 hours before remifentanil infusion and 4, 8, 24, and 48 hours after infusion. The expression levels of DRP1 and NR₂B were measured after behavioral testing using Western blotting. In addition, DRP1 expression was knocked down by intrathecal administration of AS-DRP1 to investigate the effects of DRP1 on RIH. The behavioral testing, the expression levels of spinal DRP1 and NR₂B, and dorsal mitochondrial superoxide were measured. Changes in mitochondrial morphology were assessed using electron microscopy.

Results

After remifentanil exposure, upregulation of spinal DRP1 and NR₂B was observed along with a reduction in PWMT and PWTL. In addition, AS-DRP1 improved RIH-induced PWTL and PWMT (P < 0.001 and P < 0.001) and reduced remifentanil-mediated enhancement of spinal DRP1 and NR₂B expression (P = 0.020 and P = 0.022). More importantly, AS-DRP1 reversed RIH-induced mitochondrial fission (P = 0.020) and mitochondrial superoxide upregulation (P = 0.031).

Conclusions

These results indicate that AS-DRP1 could modulate NMDA receptor expression to prevent RIH through the DRP1-mitochondria-ROS pathway.

Effective dose of remimazolam co-administered with remifentanil to facilitate I-gel insertion without neuromuscular blocking agents: an up-and-down sequential allocation trial

BACKGROUND

Remimazolam is a new anesthetic drug developed and is an ultra-short-acting agent with rapid onset and offset. The pharmacology of this drug seems to be ideal for short surgeries eligible for I-gel insertion. Therefore, this study aimed to determine the optimal bolus dose of remimazolam for I-gel insertion when co-administered with remifentanil without neuromuscular blocking agents (NMBAs).

METHODS

Patients aged 19-65 years with American Society of Anesthesiologists physical status I or II scheduled for general anesthesia were enrolled. The first dose of remimazolam was 0.15 mg/kg and remifentanil was co-administered at an effect-site concentration (Ce) of 3.0 ng/mL. The dose of remimazolam for the following patient was decreased or increased by 0.05 mg/kg depending on the success or failure of I-gel insertion in the previous patient.

RESULTS

The remimazolam bolus dose required for successful I-gel insertion in 50% of adult patients using modified Dixon's up-and-down method with remifentanil Ce 3.0 ng/mL and no NMBAs was 0.280 ± 0.048 mg/kg. Isotonic regression analysis showed that the 50% and 95% effective doses were 0.244 (83% confidence interval [CI] 0.213-0.313) mg/kg and 0.444 (95% CI 0.436-0.448) mg/kg, respectively. The mean time to loss of consciousness (Modified Observer's Assessment of Alertness/Sedation score < 2) was 52.2 s. Three patients (12.0%) showed a reduction in systolic blood pressure of more than 30% from baseline.

CONCLUSIONS

Selecting the appropriate dose of remimazolam/remifentanil without NMBAs makes it feasible to insert the I-gel.

TRIAL REGISTRATION

This study protocol was registered at http://cris.nih.go.kr (KCT0007801, 12th, October, 2022).

Median Effective Dose of Remifentanil for the Prevention of Pain Caused by the Injection of Rocuronium: An Age-Stratified Study

INTRODUCTION

Rocuronium intravenous pain is common in induction of general anesthesia. The aim of our study was to determine the median effective dose (ED₅₀) of prophylactic intravenous remifentanil for the prevention of rocuronium injection pain and to explore the effect of age on the ED₅₀.

METHODS

Eighty-nine adult patients undergoing elective general anesthesia, ASA I or II, regardless of gender or weight, were stratified according to age: group R1 18-44 years, group R2 45-59 years, and group R3 60-80 years. The initial dose of prophylactic remifentanil before rocuronium injection was set at 1 μg/kg lean body weight (LBW). The remifentanil doses were adjusted according to the degree of injection pain using the Dixon sequential method, with a ratio of 1.1 between adjacent doses. Injection pain was graded, and the occurrence of injection pain and adverse reactions were recorded. The ED₅₀ and 95% confidence intervals (CIs) of remifentanil were calculated using the Dixon-Massey formula. Patients were asked whether they recalled feeling any injection pain in the post-anesthesia care unit (PACU).

RESULTS

The ED₅₀ (95% CIs) of prophylactic remifentanil for the prevention of rocuronium injection pain were 1.266 μg/kg (1.186-1.351 μg/kg), 1.188 μg/kg (1.065-1.324 μg/kg), and 1.070 μg/kg (1.014-1.129 μg/kg) LBW in group R1, group R2, and group R3, respectively. No adverse reactions to remifentanil occurred in any group. In PACU, 84.6, 86.7, and 85.7% of patients who experienced injection pain had memories of the pain in group R1, group R2, and group R3, respectively.

CONCLUSIONS

Prophylactic intravenous remifentanil can prevent rocuronium injection pain, and its ED₅₀ decreases with age, with 1.266 μg/kg (18-44 years), 1.188 μg/kg (45-59 years), and 1.070 μg/kg LBW (60-80 years), respectively.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05217238 (registration date 18 Dec 2021).

Is Sedation of Choice in Thyroplasty Surgery? A Study on the Effects of Sedatives on Voice Quality

OBJECTIVE

In order to establish the ideal anesthetic protocol in thyroplasty type I surgery, where the intraoperative voice test is used to guide the medialization of the paralyzed fold, we have studied the effects of a sedation with midazolam premedication and adjusted intravenous doses of propofol and remifentanil on voice quality in patients without vocal fold pathology undergoing otorhinolaryngology surgery other than thyroplasty.

STUDY DESIGN

Prospective cross-sectional study included 40 adult patients.

METHOD

A voice recording was performed when the patient was fully awake and when an appropriate level of conscious sedation was reached. Following premedication with midazolam at anxiolytic doses, remifentanil and propofol were administrated by target controlled infusion pumps (TCI). These results were compared with those obtained in a previous study carried out by the same team using intravenous bolus (IV) according to weight. The recorded voice analysis was performed using the computer program Praat (v.5.3.39) for a sustained vowel.

RESULTS

All the parameters obtained from the acoustic analysis of the voice were altered after sedation with target controlled infusion in a statistically significant way. Comparing with bolus intravenous, harmonic and noise ratio (HNR) was the only parameter that decreased less in the TCI group.

CONCLUSION

The state of sedation obtained using midazolam premedication, propofol and remifentanil adjusted intravenous doses alters significantly all the voice parameters, although this alteration is considerably less than the changes produced by the medication administered in bolus IV. According to these results, the sedation and the voice test during thyroplasty surgery would present a series of limitations when it comes to guiding the medialization of the paralyzed vocal fold and therefore it could not be considered as the ideal anesthetic protocol in thyroplasty surgery.

Hemodynamic responses to 1 MAC desflurane inhalation during anesthesia induction with propofol bolus and remifentanil continuous infusion: a prospective randomized single-blind clinical investigation

BACKGROUND

Desflurane is not recommended during anesthesia induction because of its sympathetic stimulation effect, particularly in patients with myocardial ischemic disease. To date, the hemodynamic response to 1 MAC desflurane inhalation in combination with remifentanil infusion during anesthesia induction has rarely been reported.

METHODS

This investigation was designed to compare hemodynamic responses to 1 MAC desflurane (group D, n = 200) with sevoflurane (group S, n = 200) during anesthesia induction and endotracheal intubation in adult patients undergoing elective spine surgery. Subgroup analysis of the different age subgroups was also performed. With continuous infusion of remifentanil 0.1 μg/kg/min, anesthesia was induced with propofol bolus, and endotracheal intubation was performed after muscle relaxation. Heart rate (HR) and mean arterial blood pressure (MAP) were measured every minute for 5 min after anesthesia induction (T1-5) and after endotracheal intubation (T6-10).

RESULTS

HR was significantly higher in group D (n = 182) than in group S (n = 173) at T3-10 except at T6 (1 min after intubation) (all P < 0.05). In the age-based subgroup analyses, which subdivided the group D and S into four subgroups based on patient's age, the changes in HR from baseline values were significantly different between the coeval subgroups of patients in their 20-29 years and 30-39 years of age (all P < 0.05). MAP was reduced from baseline value, irrespective of group and age.

CONCLUSION

Inhalation of 1 MAC desflurane during anesthesia induction with propofol bolus and remifentanil continuous infusion and during endotracheal intubation was more likely to induce elevations in HR more likely than 1 MAC sevoflurane, especially in younger patients.

TRIAL REGISTRATION

This study was registered in the Clinical Research Information Service (CRIS, http://cris.nih.go.kr ) of the Republic of Korea on Feb 12, 2016 (Registration No. KCT 0,001,813).

Effect of common OPRM1, COMT, SLC6A4, ABCB1, and CYP2B6 polymorphisms on perioperative analgesic and propofol demands on patients subjected to thyroidectomy surgery

BACKGROUND

Perioperative anesthetic and/or analgesic demand present considerable variation, and part of that variation appears to be genetic in origin. Here we investigate the impact of common polymorphisms in OPRM1, COMT, SLC6A4, ABCB1, and CYP2B6 genes, on the intra-operative consumption of remifentanil and propofol, as well as the postoperative analgesic needs, in patients subjected to thyroidectomy surgery.

METHODS

We conducted a prospective cohort study with 90 patients scheduled to undergo elective thyroidectomy, under total intravenous anesthesia achieved by target control infusion (TCI) of propofol and remifentanil. Postoperative analgesics were administered by protocol and on-demand by the individual patient. Genotyping was established by PCR-RFLP methods. Genotyping data, intra-operative hemodynamics, and total consumption of remifentanil and propofol, as well as postoperative analgesic needs and pain perception, were recorded for each individual.

RESULTS

Patients with the ABCB1 3435TT genotype appeared to experience significantly less pain within one hour post-operatively, compared to C carriers [mean VAS (SD) = 0.86 (1.22) vs. 2.42 (1.75); p = 0.017], a finding limited to those seeking rescue analgesic treatment. Intra-operatively, homozygotes patients for the minor allele of OPRM1 A118G and CYP2B6 G516T appeared to consume less remifentanil [mean (SD) = 9.12 (1.01) vs. 13.53 (5.15), for OPRM1 118GG and A carriers] and propofol [median (range) = 14.95 (11.53, 1359.5) vs. 121.4 (1.43, 2349.4), for CYP2B6 516TT and G carriers, respectively] but the difference was not statistically significant in our sample.

CONCLUSIONS

The ABCB1 C3435T polymorphism appears to affect the postoperative perception of surgical pain among patients with low pain threshold. The small number of minor allele homozygotes for the OPRM1 A118G and CYP2B6 G516T polymorphisms precludes a definitive conclusion regarding the inclusion of the latter in a TCI-programming algorithm, based on the results of this study.

CLINICAL TRIAL REGISTRATION NUMBER

ACTRN12616001598471.

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.

Safety and efficacy of target controlled infusion administration of propofol and remifentanil for moderate sedation in non-hospital dental practice

Background

Fearful and anxious patients who find dental treatment intolerable without sedative and analgesic support may benefit from moderate sedation. Target controlled infusion (TCI) pumps are superior to bolus injection in maintaining low plasma and effect-site concentration variability, resulting in stable, steady-state drug concentrations. We evaluated the safety and efficacy of moderate sedation with remifentanil and propofol using TCI pumps in non-hospital dental settings.

Methods

A prospective chart review was conducted on 101 patients sedated with propofol and remifentanil using TCI pumps. The charts were completed at two oral surgeons and one general dentist's office over 6 months. Hypoxia, hypotension, bradycardia, and over-sedation were considered adverse events and were collected using Tracking and Reporting Outcomes of Procedural Sedation (TROOPS). Furthermore, patient recovery time, sedation length, drug dose, and patient satisfaction questionnaires were used to measure sedation effectiveness.

Results

Of the 101 reviewed sedation charts, 54 were of men, and 47 were of women. The mean age of the patients was 40.5 ±18.7 years, and their mean BMI was 25.6 ± 4.4. The patients did not experience hypoxia, bradycardia, and hypotension during the 4694 min of sedation. The average minimum Mean Arterial Pressure (MAP) and heartbeats were 75.1 mmHg and 60.4 bpm, respectively. 98% of patients agreed that the sedation technique met their needs in reducing their anxiety, and 99% agreed that they were satisfied with the sedation 24 hours later. The average sedation time was 46.9 ± 55.6 min, and the average recovery time was 12.4 ± 4.4 min. Remifentanil and propofol had mean initial effect-site concentration doses of 0.96 µ/ml and 1.0 ng/ml respectively. The overall total amount of drug administered was significantly higher in longer sedation procedures compared to shorter ones, while the infusion rate decreased as the procedural stimulus decreased.

Conclusion

According to the results of this study, no patients experienced adverse events during sedation, and all patients were kept at a moderate sedation level for a wide range of sedation times and differing procedures. The results showed that TCI pumps are safe and effective for administering propofol and remifentanil for moderate sedation in dentistry.

The effects of intravenous remifentanil on umbilical artery serum-derived exosomes in parturients undergoing epidural anesthesia: a randomized trail

BACKGROUND

Umbilical artery serum-derived exosomes (UEs) serve as messengers for maternal-fetal information exchange and cellular regulation. Intravenous remifentanil could be considered as an effective adjunct to epidural anesthesia in providing a favorable analgesia effect for cesarean section (C-section), but its effects on UEs are currently unknown.

METHODS

From 01/12/2021 to 30/06/2022, eligible parturients scheduled for repeated C-section at the First Affiliated Hospital of Wenzhou Medical University were randomized to receive either an intravenous bolus (0.15 μg/kg) followed by a continuous infusion (0.075 μg/kg/min) of remifentanil or normal saline throughout the procedure. The primary outcome was the number of UEs. Secondary outcomes included the size and protein amount of UEs, the vital signs, visceral pain score, sedation score, maternal satisfaction score, Apgar score, the incidence of neonatal asphyxia, umbilical arterial pH, and the presence of complications.

RESULTS

Nanoparticle tracking analysis indicated similar size of UEs between the two groups, but the number and protein amount of UEs were increased in the remifentanil group  compared to the control group (P < 0.05). In parturients receiving remifentanil, visceral pain scores were decreased, which was accompanied by the increased scores of maternal satisfaction with the anesthetic method (P < 0.05). Other maternal and neonatal outcomes were comparable between the two groups (P > 0.05).

CONCLUSION

The intravenous administration of remifentanil increased the number of UEs in parturients undergoing repeated C-section under epidural anesthesia, with improved birth experience and minimal neonatal complications.

Application of different concentrations of sevoflurane with remifentanil in radical surgery for gastrointestinal tumors: Effects on intraoperative hemodynamics and postoperative anesthetic recovery

BACKGROUND

The combination of remifentanil and sevoflurane can provide patients with sufficient analgesic and sedative effects. Anesthesia for gastrointestinal tumor surgery not only needs to reach the required depth of anesthesia for surgery, but also needs to reduce the surgical stress to ensure rapid recovery after surgery.

AIM

To explore the application of different concentrations of sevoflurane with remifentanil in radical surgery for gastrointestinal tumors and the effects on intraoperative hemodynamics and postoperative anesthesia recovery.

METHODS

Eighty-six patients undergoing radical surgery for gastrointestinal tumors at our hospital from January 2020 to December 2021 were selected and divided into two groups by random number table method, with 43 cases in each group. Sevoflurane at a 1.0 minimum alveolar effective concentration (MAC) with remifentanil was adopted in group A, and 1.5 MAC sevoflurane with remifentanil was adopted in group B. The quality of anesthesia, intraoperative hemodynamics [mean arterial pressure (MAP) and heart rate (HR)], cerebral oxygen metabolism [cerebral oxygen uptake rate (CERO₂) and jugular venous oxygen content (SjvO₂)] at different time points, adverse events during anesthesia maintenance, and postoperative anesthesia recovery were recorded in the two groups.

RESULTS

During maintenance of anesthesia, the rate of adjustment of remifentanil pumping rate was lower in group A than in group B (32.56% vs 67.44%, P < 0.05). There was no significant difference in HR or MAP at each time point between the two groups (P > 0.05), and both HR and MAP were within the normal range. There was no significant difference in CERO₂ or SjvO₂ at each time point between the two groups (P > 0.05); CERO₂ at T2, T3, T4, T5, and T6 in both groups was lower than that at T1, and SjvO₂ was higher than that at T1 (P < 0.05). The incidence of hypotension during anesthesia maintenance in group A was lower than that in group B (P < 0.05). The times to open eyes on command, recovery of spontaneous breathing, extubation, and exit from the room during anesthesia awakening were shorter in group A than in group B (P < 0.05).

CONCLUSION

Both 1.0 MAC and 1.5 MAC sevoflurane can meet the demand for anesthesia maintenance in surgery for radical gastrointestinal tumors; however, 1.0 MAC sevoflurane can provide better quality of anesthesia maintenance with less effect on cerebral oxygen metabolism, which can significantly improve the quality of awakening and shorten the anesthesia awakening time, and is conducive to faster clinical turnaround.

Anesthesia for ovarian teratoma resection using remimazolam and remifentanil in a patient with anti-N-methyl-D-aspartate receptor encephalitis -two case reports

BACKGROUND

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis is a type of autoimmune encephalitis that causes characteristic symptoms through the formation of antibodies against NMDA receptors. If ovarian teratomas are detected, surgical removal under general anesthesia is often considered. Many general anesthetic agents inhibit NMDA receptors. As such, anesthetic agents may have unexpected effects on disease progression. For anesthesiologists, providing general anesthesia for these patients is challenging and there are few studies on which anesthetic is most appropriate.

CASE

Two female patients were diagnosed with anti-NMDA receptor encephalitis and ovarian teratomas. Successful teratoma resection was performed under general anesthesia using remimazolam and remifentanil. After the surgery, one patient showed some improvement but died a month later. The other patient progressively improved over time.

CONCLUSIONS

Remimazolam and remifentanil are useful general anesthetic agents for patients with anti-NMDA receptor encephalitis. Further studies are warranted.

Remifentanil attenuates endoplasmic reticulum stress and inflammatory injury in LPS-induced damage in HK-2 cells

Renal injury is a fatal complication in critically ill patients with sepsis. As an ultrashort-acting synthetic opioid derivative, remifentanil has been reported to mitigate renal injury and sepsis. Nevertheless, whether remifentanil also suppresses sepsis-triggered renal injury is uncertain. The aim of this study was to investigate the effect of remifentanil on endoplasmic reticulum stress (ERS) and inflammatory response in an in vitro lipopolysaccharide (LPS)-stimulated renal tubular epithelial cell (HK-2) model and its mechanism. The viability of HK-2 cells with the absence or presence of LPS treatment was surveyed by cell counting kit-8 assay. Under the condition of LPS treatment, apoptosis was appraised by TUNEL assay and western blot. Levels of inflammatory factors were estimated though corresponding kits. Western blot tested the expression of toll-like receptor 4 (TLR4)/nuclear factor-kappaB (NF-κB) signaling-associated proteins. Also, the expression of ERS-related proteins was detected by western blot. Further, ERS inducer tunicamycin (TM) was added and the aforementioned experiments were conducted again. The results underlined the protective effects of remifentanil on LPS-evoked viability injury, inflammation, activation of TLR4/NF-κB signaling and ERS in HK-2 cells. Moreover, the impacts of remifentanil on the biological events of LPS-insulted HK-2 cells were all reversed by TM administration. To conclude, remifentanil might have a remarkable ameliorative effect on sepsis-induced renal injury, which implied the potential of remifentanil-based drug therapy in sepsis-induced renal injury.

Spinal NLRP3 inflammasome activation mediates IL-1β release and contributes to remifentanil-induced postoperative hyperalgesia by regulating NMDA receptor NR1 subunit phosphorylation and GLT-1 expression in rats

BACKGROUND

Trafficking and activation of N-methyl-D-aspartate (NMDA) receptors play an important role in initiating and maintaining postoperative remifentanil-induced hyperalgesia (RIH). Activation of the NOD-like receptor protein 3 (NLRP3) inflammasome has been linked to the development of inflammatory and neuropathic pain. We hypothesized that activation of NLRP3 inflammasome mediates IL-1β release and contributes to RIH in rats by increasing NMDA receptor NR1 (NR1) subunit phosphorylation and decreasing glutamate transporter-1 (GLT-1) expression.

METHODS

Acute exposure to remifentanil (1.2 μg/kg/min for 60 min) was used to establish RIH in rats. Thermal and mechanical hyperalgesia were tested at baseline (24 h before remifentanil infusion) and 2, 6, 24, and 48 h after remifentanil infusion. The levels of IL-1β, GLT-1, phosphorylated NR1 (phospho-NR1), and NLRP3 inflammasome activation indicators [NLRP3, Toll-like receptor 4 (TLR4), P2X purinoceptor 7 (P2X7R), and caspase-1] were measured after the last behavioral test. A selective IL-1β inhibitor (IL-1β inhibitor antagonist; IL-1ra) or three different selective NLRP3 inflammasome activation inhibitors [(+)-naloxone (a TLR4 inhibitor), A438079 (a P2X7R inhibitor), or ac-YVADcmk (a caspase-1 inhibitor)] were intrathecally administered immediately before remifentanil infusion into rats.

RESULTS

Remifentanil induced significant postoperative hyperalgesia, increased IL-1β and phospho-NR1 levels and activated the NLRP3 inflammasome by increasing TLR4, P2X7R, NLRP3, and caspase-1 expression, but it decreased GLT-1 expression in the L4-L6 spinal cord segments of rats, which was markedly improved by intrathecal administration of IL-1ra, (+)-naloxone, A438079, or ac-YVADcmk.

CONCLUSION

NLRP3 inflammasome activation mediates IL-1β release and contributes to RIH in rats by inducing NMDA receptor NR1 subunit phosphorylation and decreasing GLT-1 expression. Inhibiting the activation of the NLRP3 inflammasome may be an effective treatment for RIH.

Effects of fentanyl administration in mechanically ventilated patients in the intensive care unit: a systematic review and meta-analysis

BACKGROUND

Fentanyl is selected to manage pain in critical care patients on mechanical ventilation in the intensive care unit (ICU). However, the usefulness of fentanyl compared with other opioids is unknown. This study examined the evidence for using fentanyl to improve the clinical outcomes of ICU patients, using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

METHODS

We searched the MEDLINE, Cochrane Central Register of Controlled Trials, and Igaku Chuo Zasshi databases in June 2021. Two independent assessors reviewed studies to identify randomized, controlled trials (RCTs) that compared the intravenous administration of fentanyl and other opioids in mechanically ventilated patients in the ICU. The study quality was assessed using the GRADE system and Cochrane methodology. The primary outcome was mortality. The secondary outcomes were the duration of mechanical ventilation, duration of the ICU stay, incidence of severe adverse events, and incidence of delirium. We integrated outcome data using a random-effects model and showed absolute values and certainty of evidence in the GRADE evidence profile.

RESULTS

Seven RCTs met the study inclusion criteria with 534 patients (251 were treated with fentanyl and 283 with other opioids, including 242 with remifentanil and 41 with morphine). Among 191 participants from 2 RCTs, fentanyl was not associated with mortality (risk ratio [RR], 0.79; 95% confidence interval [CI], 0.24 to 2.60; low-quality evidence). Regarding the secondary outcomes, fentanyl did not shorten the duration of mechanical ventilation (mean difference, 0.49 h; 95% CI, - 0.90 to 1.88; moderate-quality evidence) or the duration of the ICU stay (mean difference, 7.04 h; 95% CI, - 3.27 to 17.35; moderate-quality evidence) compared with other opioids. Fentanyl did not increase the incidence of severe adverse events (RR, 0.98; 95% CI, 0.50 to 1.90; low-quality evidence) or delirium (RR, 1.27; 95% CI, 0.79 to 2.04; low-quality evidence).

CONCLUSIONS

Although fentanyl is a frequently administered opioid in the ICU, patients' outcomes are not different between fentanyl use and use of other opioids. However, the GRADE evaluation provides little certainty to support the results of this systematic review. Therefore, further large RCTs are required to confirm our conclusions.

TRIAL REGISTRATION

PROSPERO, CRD42019130648 ( https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=130648 ).