Low-dose Remifentanil Research Articles

Serum neurofilament light release levels as marker of neurotoxicity in general anesthesia versus hypnosis: A prospective non-randomized trial

Background: Whether general anesthetics induce neurotoxicity is unclear. Objectives: We hypothesized that serum neurofilament light (NfL) release, a marker of neural injury, would not be different in patients receiving general anesthesia (GA) compared to hypnosis. Design: Prospective, non-randomized. Setting: Tertiary university hospital. Methods: Patients undergoing breast cancer or thyroid/parathyroid surgery were enrolled. Propofol and remifentanil were used for GA. For hypnosis, only low dose remifentanil was allowed. Main outcome measures: NfL was measured at baseline, at day 1 and at postoperative visit. At preoperative and postoperative visit, patients performed a Montreal Cognitive Assessment (MoCA) test. Primary outcome was absolute change in NfL at day 1 between groups. Results: Among 100 included patients, 51 were in GA and 49 in hypnosis group. There were 26/49 (53%) breast cancer patients in hypnosis group and 13/51 (26%) in GA arm, p = 0.005. Baseline NfL was higher in the hypnosis group (p = 0.050). We subtracted log-transformed baseline NfL from postoperative NfL to analyze normalized values as absolute change. The mean normalized value at day 1 (primary endpoint) was 0.02 (± 0.11) in the GA and 0.03 (± 0.20) in the hypnosis group; p = 0.979 [d = 0.16, 95% CI: -0.40 to 0.39]. In a linear mixed-effects model including variables that influenced baseline NfL (advanced age, higher creatinine values, breast cancer), mean difference (95 % CI) in absolute change of log NfL at day 1 between both groups was 0.007 (- 0.04 to 0.06); p = 0.791. A change in MoCA as compared to baseline was not different between groups (p = 0.761). Conclusions: Our results show that there was no statistical or clinical difference in postoperative NfL release between GA and hypnosis. GA with propofol was not associated with a different risk of neural injury compared to hypnosis. Trial registration: NCT04500236.

Conscious sedation anesthesia using different doses of remifentanil combined with dexmedetomidine for peritoneal dialysis catheter implantation

Background Conscious sedation anesthesia (CSA) is an anesthetic method during peritoneal dialysis catheter implantation. However, lack of optimal CSA strategies for patients with end-stage renal disease (ESRD). This study aimed to evaluate the analgesic effects and safety of CSA using different doses of remifentanil combined with dexmedetomidine during peritoneal dialysis catheter insertion. Methods Patients who underwent peritoneal dialysis (PD) catheter placement via open surgical incision were retrospectively analyzed and divided into three groups based on the tertile dose of remifentanil. The bispectral index (BIS) was used to monitor the depth of anesthesia. Data regarding clinical findings, the effects of anesthesia, and the incidence of drug-related adverse effects were collected. Results In total, 102 patients completed the surgery successfully and safely. The dose of remifentanil was 0.02–0.07 μg/kg/min, 0.08–0.13 μg/kg/min, and 0.14–0.20 μg/kg/min in Groups A, B, and C, respectively. Only seven patients reported mild pain during the surgery. No significant differences were observed among the numeric rating scale scores of the three groups (p > 0.05). Intraoperative hemodynamics were stable. The incidence of respiratory depression was 8.3%, 20.0%, and 41.9% in Groups A, B, and C, respectively (p < 0.01). The incidence of gastrointestinal symptoms in Group C (51.6%) was higher than that in Groups A and B (p < 0.05). Conclusion Low-dose remifentanil (0.02–0.07 μg/kg/min) combined with dexmedetomidine achieved satisfactory anesthetic effects with fewer adverse drug reactions during PD catheter implantation, indicating its potential for use in patients undergoing PD catheter placement.

Comparison of Two Anesthetic Regimens on Extubation Time and Postoperative Recovery in Children Undergoing Ambulatory Adenoidectomy: A Retrospective Study

PurposeThis aim of this study was to compare two anesthetic regimens in terms of extubation time and postoperative recovery in children undergoing ambulatory adenoidectomy. DesignA retrospective cohort study with propensity score matching. MethodsThe medical charts of 452 children aged between 3 and 8 years undergoing ambulatory adenoidectomy were retrieved for analysis, of which 438 were eligible to participate in this study. A majority (n = 327) were children exposed to a conventional propofol-pronounced general anesthetic regimen (high-dose propofol plus low-dose remifentanil, labeled as group P), while n = 111 were administered a modified remifentanil-pronounced anesthetic regimen (low-dose propofol plus high-dose remifentanil, namely group R). Propensity score matching was employed to adjust for confounders, resulting in 69 matched patients in each group. The primary endpoint of this study was extubation time. The secondary endpoints were total intraoperative fluid volume, length of stay in the postanesthesia care unit (PACU), postoperative pain rating, the incidence of emergence agitation, nausea and vomiting, as well as the level of consciousness (fully awake or waking by gentle patting) when transferred out of PACU, and any major complications (wound bleeding, reintubation, readmission, and overnight stay). FindingsNo major complications were observed in both groups. Compared to group P, group R had significantly shorter extubation time (8.2 ± 1.4 minutes vs 13.3 ± 2.4 minutes, P < .001), shorter length of stay in the PACU (14.1 ± 3.1 minutes vs 20.2 ± 3.4 minutes, P < .001), and a higher proportion of cases being fully awake when transferred out of the PACU (91% vs 46%, P < .001). Lastly, the pain rating, frequency of oropharyngeal airway usage, incidence of emergence agitation, and nausea and vomiting were comparable between the two groups (P > .05 for all). ConclusionsRemifentanil-pronounced anesthesia was superior to propofol-pronounced anesthesia in children undergoing ambulatory adenoidectomy, given that the former was associated with a faster recovery time from anesthesia without jeopardizing patient safety.

Epidural electrical stimulation of the cervical spinal cord opposes opioid-induced respiratory depression.

Opioid overdose suppresses brainstem respiratory circuits, causes apnoea and may result in death. Epidural electrical stimulation (EES) at the cervical spinal cord facilitated motor activity in rodents and humans, and we hypothesized that EES of the cervical spinal cord could antagonize opioid-induced respiratory depression in humans. Eighteen patients requiring surgical access to the dorsal surface of the spinal cord between C2 and C7 received EES or sham stimulation for up to 90s at 5 or 30Hz during complete (OFF-State) or partial suppression (ON-State) of respiration induced by remifentanil. During the ON-State, 30Hz EES at C4 and 5Hz EES at C3/4 increased tidal volume and decreased the end-tidal carbon dioxide level compared to pre-stimulation control levels. EES of 5Hz at C5 and C7 increased respiratory frequency compared to pre-stimulation control levels. In the OFF-State, 30Hz cervical EES at C3/4 terminated apnoea and induced rhythmic breathing. In cadaveric tissue obtained from a brain bank, more neurons expressed both the neurokinin 1 receptor (NK1R) and somatostatin (SST) in the cervical spinal levels responsive to EES (C3/4, C6 and C7) compared to a region non-responsive to EES (C2). Thus, the capacity of cervical EES to oppose opioid depression of respiration may be mediated by NK1R+/SST+ neurons in the dorsal cervical spinal cord. This study provides proof of principle that cervical EES may provide a novel therapeutic approach to augment respiratory activity when the neural function of the central respiratory circuits is compromised by opioids or other pathological conditions. KEY POINTS: Epidural electrical stimulation (EES) using an implanted spinal cord stimulator (SCS) is an FDA-approved method to manage chronic pain. We tested the hypothesis that cervical EES facilitates respiration during administration of opioids in 18 human subjects who were treated with low-dose remifentanil that suppressed respiration (ON-State) or high-dose remifentanil that completely inhibited breathing (OFF-State) during the course of cervical surgery. Dorsal cervical EES of the spinal cord augmented the respiratory tidal volume or increased the respiratory frequency, and the response to EES varied as a function of the stimulation frequency (5 or 30Hz) and the cervical level stimulated (C2-C7). Short, continuous cervical EES restored a cyclic breathing pattern (eupnoea) in the OFF-State, suggesting that cervical EES reversed the opioid-induced respiratory depression. These findings add to our understanding of respiratory pattern modulation and suggest a novel mechanism to oppose the respiratory depression caused by opioids.

Brain-based measures of nociception during general anesthesia with remifentanil: A randomized controlled trial.

BackgroundCatheter radiofrequency (RF) ablation for cardiac arrhythmias is a painful procedure. Prior work using functional near-infrared spectroscopy (fNIRS) in patients under general anesthesia has indicated that ablation results in activity in pain-related cortical regions, presumably due to inadequate blockade of afferent nociceptors originating within the cardiac system. Having an objective brain-based measure for nociception and analgesia may in the future allow for enhanced analgesic control during surgical procedures. Hence, the primary aim of this study is to demonstrate that the administration of remifentanil, an opioid widely used during surgery, can attenuate the fNIRS cortical responses to cardiac ablation.Methods and findingsWe investigated the effects of continuous remifentanil on cortical hemodynamics during cardiac ablation under anesthesia. In a randomized, double-blinded, placebo (PL)-controlled trial, we examined 32 pediatric patients (mean age of 15.8 years,16 females) undergoing catheter ablation for cardiac arrhythmias at the Cardiology Department of Boston Children’s Hospital from October 2016 to March 2020; 9 received 0.9% NaCl, 12 received low-dose (LD) remifentanil (0.25 mcg/kg/min), and 11 received high-dose (HD) remifentanil (0.5 mcg/kg/min). The hemodynamic changes of primary somatosensory and prefrontal cortices were recorded during surgery using a continuous wave fNIRS system. The primary outcome measures were the changes in oxyhemoglobin concentration (NadirHbO, i.e., lowest oxyhemoglobin concentration and PeakHbO, i.e., peak change and area under the curve) of medial frontopolar cortex (mFPC), lateral prefrontal cortex (lPFC) and primary somatosensory cortex (S1) to ablation in PL versus remifentanil groups. Secondary measures included the fNIRS response to an auditory control condition. The data analysis was performed on an intention-to-treat (ITT) basis. Remifentanil group (dosage subgroups combined) was compared with PL, and a post hoc analysis was performed to identify dose effects. There were no adverse events. The groups were comparable in age, sex, and number of ablations. Results comparing remifentanil versus PL show that PL group exhibit greater NadirHbO in inferior mFPC (mean difference (MD) = 1.229, 95% confidence interval [CI] = 0.334, 2.124, p < 0.001) and superior mFPC (MD = 1.206, 95% CI = 0.303, 2.109, p = 0.001) and greater PeakHbO in inferior mFPC (MD = −1.138, 95% CI = −2.062, −0.214, p = 0.002) and superior mFPC (MD = −0.999, 95% CI = −1.961, −0.036, p = 0.008) in response to ablation. S1 activation from ablation was greatest in PL, then LD, and HD groups, but failed to reach significance, whereas lPFC activation to ablation was similar in all groups. Ablation versus auditory stimuli resulted in higher PeakHbO in inferior mFPC (MD = 0.053, 95% CI = 0.004, 0.101, p = 0.004) and superior mFPC (MD = 0.052, 95% CI = 0.013, 0.091, p < 0.001) and higher NadirHbO in posterior superior S1 (Pos. SS1; MD = −0.342, 95% CI = −0.680, −0.004, p = 0.007) during ablation of all patients. Remifentanil group had smaller NadirHbO in inferior mFPC (MD = 0.098, 95% CI = 0.009, 0.130, p = 0.003) and superior mFPC (MD = 0.096, 95% CI = 0.008, 0.116, p = 0.003) and smaller PeakHbO in superior mFPC (MD = −0.092, 95% CI = −0.680, −0.004, p = 0.007) during both the stimuli. Study limitations were small sample size, motion from surgery, indirect measure of nociception, and shallow penetration depth of fNIRS only allowing access to superficial cortical layers.ConclusionsWe observed cortical activity related to nociception during cardiac ablation under general anesthesia with remifentanil. It highlights the potential of fNIRS to provide an objective pain measure in unconscious patients, where cortical-based measures may be more accurate than current evaluation methods. Future research may expand on this application to produce a real-time indication of pain that will aid clinicians in providing immediate and adequate pain treatment.Trial registrationClinicalTrials.gov NCT02703090

Association between the Remifentanil Dose during Anesthesia and Postoperative pain.

Remifentanil is an ultra-short-acting opioid that sometimes causes opioid-induced hyperalgesia, which has led to controversy regarding the association between intraoperative remifentanil administration and postoperative pain. This study aimed to assess the effects of the intraoperative remifentanil dose on postoperative pain. Patients undergoing esophageal, gastric/hepatobiliary, or intestinal/colon surgery and using postoperative patient-controlled epidural analgesia were analyzed. The patients were divided into two groups based on the average intraoperative remifentanil dose (high-dose remifentanil [HR] group: ≥0.1 μg/kg/min; low-dose remifentanil [LR] group: <0.1 μg/kg/min). In all, 406 patients met the inclusion criteria. A significant difference in the average dose of remifentanil was seen between the groups during the anesthesia period (0.14±0.05 vs. 0.07±0.02 μg/kg/min). However, no significant difference was seen in pre- or intraoperative patient characteristics. Numerical rating scale (NRS) scores on postoperative day 1 were similar between the groups (HR: 1.7±2.0; LR: 1.7±2.0; p=0.74). The incidence of poor pain control (NRS > 3/10) was also similar between the groups (HR: 14%; LR: 16%; p=0.57). Older age (> 60 years) and type of surgery (esophageal surgery) were associated with worse postoperative NRS scores. No significant association was seen between the intraoperative remifentanil dose and postoperative NRS scores following thoracoabdominal surgery with postoperative epidural pain management.

Remifentanil requirement for acceptable intubation conditions with two different doses of ketamine without a neuromuscular blocking agent in pediatric patients.

The optimal remifentanil concentration for improving intubation conditions when intubation is performed without neuromuscular blocking agents (NMBAs) but with ketamine as an induction agent remains unknown. Here, we aimed to identify the effective bolus doses of remifentanil required to achieve acceptable intubation conditions upon anesthesia induction with 1 or 2 mg/kg ketamine without NMBAs. In this prospective, double-blinded, randomized up-down sequential allocation study, we enrolled pediatric patients aged 3-12 years undergoing general anesthesia for inguinal hernia surgery. The patients were randomly allocated to one of two groups to receive either ketamine 1.0 mg/kg (K1 group) or 2.0 mg/kg (K2 group) intravenously until seven success-failure pairs were achieved. The remifentanil dose for each patient was determined using the modified Dixon's up-and-down method with an initial dose of 2.5 μg/kg and a step size of 0.5 μg/kg. In total, 51 patients (22 in the K1 group and 29 in the K2 group) were enrolled. The effective dose (ED)50s of remifentanil for obtaining clinically acceptable intubation conditions under anesthesia induction with ketamine but without NMBAs was 3.2 μg/kg in the K1 group and 1.6 μg/kg in the K2 group. High-dose remifentanil with 1 mg/kg ketamine was associated with more severe chest wall rigidity and lower mean blood pressure and heart rate than was low-dose remifentanil with 2 mg/kg ketamine. The ED50 of remifentanil required for clinically acceptable intubation conditions with anesthesia induction using 1 mg/kg ketamine without NMBAs in pediatric patients was twice that when using 2 mg/kg ketamine. The combination of 2 mg/kg ketamine and remifentanil was better at preventing chest wall rigidity.

Effect of Remifentanil on Postoperative Vomiting After Strabismus Surgery in Preschool Children: A Prospective Randomized Controlled Trial.

BackgroundStrabismus surgery and the use of opioid are risk factors of postoperative vomiting. We evaluated whether there is a dose-dependent effect of remifentanil on the incidence of postoperative vomiting.MethodsSixty pediatric patients who were scheduled for strabismus surgery were enrolled. Patients were randomly divided into three groups; Group H (high-dose remifentanil group), Group L (low-dose remifentanil group), and Group C (control group). After endotracheal intubation, patients in the Group H and L received an intravenous bolus dose of remifentanil of 1.0 μg/kg and 0.5 μg/kg over 2 min, respectively. Group H and L patients received a continuous infusion of remifentanil (0.1 μg/kg/min) during the surgery. The patients in Group C did not have any dose of remifentanil. Intravenous fentanyl (1 µg/kg) was administered to the patients for postoperative pain control.ResultsThe primary outcome was a difference of the incidence of postoperative vomiting within 24 hours after surgery. There was no significant difference in incidence of postoperative vomiting between three groups. The degree of emergence agitation and postoperative pain did not show any significant difference between three groups.ConclusionsThe intraoperative administration of remifentanil did not show dose-dependent effect on postoperative vomiting in pediatric strabismus surgery.

Comparison of the effects of target-controlled infusion-remifentanil/midazolam and manual fentanyl/midazolam administration on patient parameters in dental procedures.

BackgroundModerate sedation is an integral part of dental care delivery. Target-controlled infusion (TCI) has the potential to improve patient safety and outcome. We compared the effects of using TCI to administer remifentanil/manual bolus midazolam with manual bolus fentanyl/midazolam administration on patient safety parameters, drug administration times, and patient recovery times.MethodsIn this retrospective chart review, records of patients who underwent moderate intravenous sedation over 12 months in a private dental clinic were assessed. Patient indicators (pre-, intra-, and post-procedure noninvasive systolic and diastolic blood pressure, respiration, and heart rate) were compared using independent t-test analysis. Patient recovery time, procedure length, and midazolam dosage required were also compared between the two groups.ResultsEighty-five patient charts were included in the final analysis: 47 received TCI-remifentanil/midazolam sedation, and 38 received manual fentanyl/midazolam sedation. Among the physiological parameters, diastolic blood pressure showed slightly higher changes in the fentanyl group (P = 0.049), respiratory rate changes showed higher changes in the fentanyl group (P = 0.032), and the average EtCO2 was slightly higher in the remifentanil group (P = 0.041). There was no significant difference in the minimum SpO2 levels and average procedure length between the fentanyl and remifentanil TCI pump groups (P > 0.05). However, a significant difference was observed in the time required for discharge from the chair (P = 0.048), indicating that patients who received remifentanil required less time for discharge from the chair than those who received fentanyl. The dosage of midazolam used in the fentanyl group was 0.487 mg more than that in the remifentanil group; however, the difference was not significant (P > 0.05).ConclusionThe combination of TCI administered remifentanil combined with manual administered midazolam has the potential to shorten the recovery time and reduce respiration rate changes when compared to manual administration of fentanyl/midazolam. This is possibly due to either the lower midazolam dosage required with TCI remifentanil administration or achieving a stable, steady-state low dose remifentanil concentration for the duration of the procedure.

Pre-emptive remifentanil alleviates pain associated with tracheal suctioning in patients under mechanical ventilation and goal-directed sedation: A randomized controlled feasibility trial.

To investigate the efficacy of pre-emptive remifentanil in alleviating pain during tracheal suctioning in patients under mechanical ventilation. Goal-directed sedation is recommended for patients under mechanical ventilation by the current guidelines. Whether goal-directed sedation can prevent pain during tracheal suctioning in these patients is unknown. This was a two-centre, randomized, crossover, single-blind trial conducted between August and October 2019. Patients under mechanical ventilation received low-dose remifentanil, high-dose remifentanil or placebo prior to each tracheal suctioning in a random order. The primary outcomes were evaluated using the critical-care pain observation tool and Richmond agitation-sedation scale after tracheal suctioning. Adverse events were also documented. A total of 39 patients who underwent 117 tracheal suctions were enrolled. After the tracheal suction, changes in the critical-care pain observation tool and Richmond agitation-sedation scale scores were significantly lower in the low-dose and high-dose groups than in the placebo group (P<0.001). A non-significant increase in the absence of spontaneous breathing was observed in the high-dose group compared to that in the placebo group. A pre-emptive remifentanil bolus of 0.5μg/kg can mitigate the pain associated with tracheal suctioning.

Remifentanil for Carboprost-Induced Adverse Reactions During Cesarean Delivery Under Combined Spinal-Epidural Anesthesia

PurposeCarboprost may induce adverse reactions when used to treat postpartum hemorrhage. We aimed to explore the effects of intravenous infusion of low-dose remifentanil to prevent such reactions.MethodsWe enrolled parturient patients scheduled for elective cesarean section. Anesthesiologist administered combined spinal epidurals at the L3/4 interspace, with 0.5% hyperbaric bupivacaine subarachnoid space injections (1.5–2.5 ml). We randomly divided parturient patients, administered carboprost during surgery, into the remifentanil group (group R) and the control group (group C). Patients in group R received an intravenous target-controlled infusion of remifentanil (target effect-site concentration, 1.5 ng/ml) simultaneously with a carboprost tromethamine injection (250 µg). Patients in group C received a normal saline infusion with carboprost. We recorded and analyzed the incidence of carboprost-related adverse reactions (vomiting, nausea, chest congestion, flushing, hypertension, tachycardia, cough, and shivering), and assessed patient comfort using a numerical rating scale ([NRS], on which 0 was very uncomfortable and 10 was very comfortable).ResultsAfter applying inclusion and exclusion criteria, we conducted statistical analysis of the data from 70 women. The incidence of vomiting was significantly lower in group R than in group C (14.3 vs. 51.4%, p < 0.01); and the incidence of nausea, chest congestion, facial flushing, and hypertension were significantly lower in group R than in group C (all p < 0.01). Furthermore, the patients’ comfort scores were significantly higher in group R than in group C (8.0 ± 1.8 vs. 3.6 ± 2.1, p < 0.01).ConclusionOur results demonstrate that an intravenous low-dose remifentanil infusion can effectively prevent carboprost-related adverse reactions during cesarean delivery under combined spinal and epidural anesthesia.Clinical Trial RegistrationWe pre-registered this study at http://www.chictr.org.cn/showproj.aspx?proj=27707 (ChiCTR1800016292).

Remifentanil improves myocardial ischemia-reperfusion injury in rats through inhibiting IL-18 signaling pathway.

To explore the protective effect of remifentanil against myocardial ischemia-reperfusion injury (MIRI) in rats and its mechanism. The rat models of IRI were established and randomly divided into 1) sham-operation group (S group), 2) IRI rat model group (M group), 3) low-dose remifentanil group (R-L group), 4) moderate-dose remifentanil group (R-M group), and 5) high-dose remifentanil group (R-H group). The rats in R-L group, R-M group, and R-H group were administrated with remifentanil at 0.4 μg/kg/min, 2 μg/kg/min, and 10 μg/kg/min, respectively. The activity of creatine kinase-MB (CK-MB), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) in myocardial cells was detected using the automatic biochemical analyzer, and the apoptosis rate of myocardial cells was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Moreover, the messenger ribonucleic acid (mRNA) and protein levels of related cytokines in myocardial cells were determined through quantitative Polymerase Chain Reaction (qPCR) and Western blotting, and the content of interleukin-1β (IL-1Symbol ) and IL-18 in peripheral blood was detected via enzyme-linked immunosorbent assay (ELISA). Remifentanil at different concentrations could protect myocardium from IRI, and remifentanil at 2 μg/kg/min and 10 μg/kg/min could significantly down-regulate the myocardial enzyme indexes in IRI myocardial cells (p<0.01). Besides, remifentanil reduced the mRNA expressions of IL-18, INF-γ, TNF-β, and IL-1β (p<0.01), significantly decreased the protein expression of IL-18, and raised the protein expression of IL-18BP, thereby improving myocardial pathological damage. The protective mechanism of remifentanil on the myocardium of MIRI rats may be related to the inhibition on the IL-18 signaling pathway.

Remifentanil attenuates cardiac dysfunction, lipid peroxidation and immune disorder in rats with isoproterenol-induced myocardial injury via JNK/NF-KB p65 inhibition.

BackgroundMyocardial injury caused by myocardial ischemia (MI) is still a severe condition that can result in apoptosis, oxidative stress, and inflammation. Remifentanil is a selective, ultra-short-acting, µ-opioid receptor agonist opioid. It can improve sinusoidal heart rate patterns in the fetus, for bupivacaine-induced cardiotoxicity, and with lipopolysaccharide (LPS)-induced cardiomyocytes injuries. This study aimed to explore the cardioprotective effects of remifentanil in MI model rats.MethodsSprague Dawley (SD) rats were split into five groups at random, including a control group, Isop group, low-dose remifentanil treatment group (10 µg/kg), medium-dose remifentanil treatment group (20 µg/kg), and a high-dose remifentanil treatment group (40 µg/kg). The MI model was achieved by subcutaneously injecting rats with isoproterenol (85 mg/kg) for two consecutive days. With the expression of apoptotic molecules, myocardial systolic function index, inflammation, antioxidant enzymes, and the myocardial enzyme taken into account, the data was analyzed.ResultsAfter treatment with remifentanil, the left ventricular wall thickness (LVWT), left ventricular end-systolic volume (LVESV), left ventricular ejection fraction (LVEF), fraction shortening (FS), and heart rate (HR) were significantly increased in comparison with the Isop group. Creatine kinase-MB (CK-MB), Mb, and cTnl expressions were decreased. Meanwhile, the levels of cleaved caspase-3 and caspase-9 were decreased. Remarkably, the levels of reactive oxidative species (ROS), malondialdehyde (MDA), and lactate dehydrogenase (LDH) were observed to be repressed, while the levels of superoxide dismutase (SOD) was significantly increased. More importantly, the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and interferon (IFN)-γ were decreased.ConclusionsRemifentanil has significant potential as a therapeutic intervention strategy for ameliorating myocardial injury after MI and these findings provide the rationale for further clinical studies.

Effects of low-dose remifentanil infusion on analgesic or antiemetic requirement during brain function mapping: A retrospective cohort study.

Pain and discomfort during the awake phase in awake craniotomy should be relieved to facilitate brain mapping. Although some anaesthesiologists use low-dose (0.01-0.05µg/kg/min) remifentanil infusion to provide analgesia during this phase, its efficacy and side effects have never been evaluated. Therefore, this study primarily aimed to investigate the effects of low-dose remifentanil infusion on the need for antiemetic treatment during brain mapping and secondarily aimed to determine its effects on the need for additional analgesic treatment. This retrospective study included 218 patients who underwent awake craniotomy at our centre from 2008 to 2018. The relationship between low-dose remifentanil infusion during the awake phase and the requirement for analgesic or antiemetic treatment was examined. A multivariable competing risk regression analysis was performed to adjust for patient and operative variables. Sixty-six patients (30.3%) received low-dose (median rate: 0.01µg/kg/min) remifentanil infusion during the awake phase. Forty-nine patients (22.5%) received an antiemetic and 99 (45.4%) received additional analgesic treatment. The difference in additional analgesic treatment was not significant between patients who received low-dose remifentanil infusion and those who did not (adjusted hazard ratio: 1.13; 95% confidence interval: 0.75-1.70; P=.570); however, the use of antiemetics significantly increased in patients who received remifentanil (adjusted hazard ratio: 1.78; 95% confidence interval: 1.01-3.15; P=.047). Low-dose remifentanil infusion during the awake phase in awake craniotomy significantly increased the need for antiemetics but did not decrease the need for additional analgesic treatment.

Regulatory effects of propofol on high-dose remifentanil-induced hyperalgesia.

We aimed to evaluate the regulatory effects of propofol on high-dose remifentanil-induced hyperalgesia. A total of 180 patients receiving laparoscopic cholecystectomy were randomly divided into sevoflurane + high-dose remifentanil (SH) group, sevoflurane + low-dose remifentanil (SL) group and propofol + high-dose remifentanil group (PH) group (n=60). After intravenous administration of midazolam, SH and SL groups were induced with sevoflurane and remifentanil, and PH group was induced with propofol and remifentanil. During anesthesia maintenance, SH and SL groups were given 0.3 microg/kg/min and 0.1 microg/kg/min sevoflurane and remifentanil respectively, and PH group was given 0.3 microg/kg/min propofol and remifentanil. The three groups had significantly different awakening time, extubation time and total dose of remifentanil (P<0.001). Compared with SL group, periumbilical mechanical pain thresholds 6 h and 24 h after surgery significantly decreased in SH group (P<0.05), and the visual analog scale (VAS) scores significantly increased 30 min, 2 h and 6 h after surgery (P<0.05). Compared with SH group, periumbilical mechanical thresholds 6 h and 24 h after surgery were significantly higher in PH group (P<0.05), and VAS scores 30 min, 2 h and 6 h after surgery were significantly lower (P<0.05). PH group first used patient-controlled intravenous analgesia pump significantly later than SL group did (P<0.05). The total consumptions of sufentanil in PH and SL groups were significantly lower than that of SH group (P<0.05). The incidence rates of bradycardia and postoperative chill in PH and SH groups were significantly higher than those of SL group (P<0.05). Anesthesia by infusion of high-dose remifentanil plus sevoflurane caused postoperative hyperalgesia which was relieved through intravenous anesthesia with propofol.

Continuous intravenous infusion of remifentanil improves the experience of parturient undergoing repeated cesarean section under epidural anesthesia, a prospective, randomized study

BackgroundUnsatisfactory analgesia would occur frequently during repeated cesarean section under epidural anesthesia. The aim of this study is to observe the effects of intravenous remifentanil on maternal comfort, maternal and neonatal safety during repeated cesarean section under epidural anesthesia.MethodsA total of 80 parturients undergoing repeated cesarean section were involved in the study. The patients were randomly divided into the intravenous remifentanil- assisted epidural group (group R) and epidural group (group E), respectively (n = 40). In group R, the remifentanil was continuously intravenously infused as an adjuvant to epidural anesthesia. In group E, 0.75% ropivacaine epidural or intravenous ketamine was administered as needed. Parturient baseline characteristics, vital signs, VAS scores, and comfort scores during surgery were recorded. Adverse effects were also recorded.ResultsA total of 80 patients were enrolled in the current study and the final analyses included 39 patients in group R and 38 patients in group E. No differences in patients’ baseline characteristics were found between the two groups (p > 0.05). Compared with group E, the comfort score was significantly higher in group R (9.1 ± 1.0 vs. 7.5 ± 1.3, p < 0.001), whereas the maximum VAS score was significantly lower in group R (1.8 ± 1.2 vs. 4.1 ± 1.0, p < 0.001). Maternal and neonatal adverse effects did not differ between the two groups during surgery (p > 0.05).ConclusionsContinuous intravenous infusion of low-dose remifentanil can significantly improve the experience of parturients undergoing repeated cesarean section under epidural anesthesia, without noticeable maternal or neonatal adverse effects.Trial registrationThis study was pre-registered at http://www.chictr.org.cn/index.aspx (ChiCTR1800018423) on 17/09/2018.

Anesthetic effect of low-dose remifentanil combined with propofol on patients undergoing sequential painless gastroscopy and painless colonoscopy

Objective To explore the anesthetic effect of low dose remifentanil in patients undergoing sequential painless gastroscopy and painless colonoscopy in accordance with intravenous induction of propofol. Methods From July 2017 to January 2018, 86 patients who needed painless gastroscopy and painless colonoscopy in sequence were selected as observation objects in the Second Hospital of Jiaxing and were divided into control group and observation group according to random number table method, with 43 cases in each group.The control group was anesthetized with propofol only, while the observation group was anesthetized with low dose remifentanil in accordance with propofol.The occurrence of adverse reactions and recovery were compared between the two groups. Results The incidence rate of adverse reactions of the control group was 20.93%(9/43), which of the observation group was 13.95%(6/43), there was no statistically significant difference between the two groups (χ2=0.272, P=394). The recovery time and the observation time after awakening in the observation group were (7.19±1.98)min and (6.94±2.04)min, respectively, which were significantly shorter than those in the control group [(10.33±2.42)min and (11.69±3.21)min], the differences were statistically significant (t=6.585, 8.190, P=0.000, 0.000). Conclusion Intravenous induction with low dose remifentanil combined with propofol in patients undergoing painless gastroscopy and painless colonoscopy in sequence has less adverse reactions, good anesthesia persistence and short recovery time, which is worthy of clinical popularization. Key words: Gastroscopy; Colonoscopy; Anesthesia and analgesia; Remifentanil; Propofol

Effects of remifentanil gradual withdrawal on remifentanil induced postoperative hyperalgesia

Objective: To explore the effects of remifentanil gradual withdrawal on remifentanil induced postoperative hyperalgesia. Methods: Ninety patients from January to June 2018 undergoing elective laparoscopic hysterectomy under general anaesthesia at Ningbo NO.2 hospital, ASA Ⅰ or Ⅱ grade, aged 20-60, were enrolled in this study and randomly assigned to 3 groups (n=30): Group L (low dose remifentanil), Group H (high dose remifentanil) and Group G (high dose remifentanil with gradual withdrawal). Mechanical pain thresholds (MPT), visual analogue scale (VAS) and additional analgesics were recorded at 6 and 24 hours after the operation. Results: There was no significant difference among the VAS and additional analgesics in three groups at 6 and 24 hours after operation (P>0.05). There was no significant difference among the MPT in three groups before operation (P>0.05). The MPT of group L, group H and group G were (49.8±12.2), (35.5±13.0) and (48.6±11.4) g at 6 hours after surgery, and (51.4±14.3), (36.9±11.1) and (48.8±11.5) g at 24 hours after surgery, respectively, with statistically significant differences (F=12.6, 11.668, both P<0.01). The MPT of group H at 6 h and 24 h after surgery was lower than that of group L (all P<0.01), while the MPT of group G at 6 h and 24 h after surgery was significantly higher than that of group H (all P<0.01). No correlation was observed between MPT and VAS scores or additional analgesics at 6 and 24 hours postoperatively (P>0.05). Conclusion: Remifentanil gradual withdrawal significantly alleviated intraoperative administration of remifentanil induced postoperative hyperalgesia in laparoscopic hysterectomy patients.

Corrigendum to "Total Intravenous Anaesthesia with High-Dose Remifentanil Does Not Aggravate Postoperative Nausea and Vomiting and Pain, Compared with Low-Dose Remifentanil: A Double-Blind and Randomized Trial".

[This corrects the article DOI: 10.1155/2014/724753.].

Effects of low-dose ketamine infusion on remifentanil-induced acute opioid tolerance and the inflammatory response in patients undergoing orthognathic surgery.

PurposeRemifentanil is associated with acute opioid tolerance that can lead to increased postoperative consumption of opioid analgesics. The purpose of this study was to determine whether a low dose of ketamine prevents remifentanil-induced acute opioid tolerance and affects the neutrophil–lymphocyte ratio (NLR), a newly recognized biomarker of inflammation.Materials and methodsForty patients undergoing orthognathic surgery were enrolled in this prospective, randomized, double-blind study and randomly assigned to intraoperative administration of one of the following anesthetic regimens: high-dose remifentanil (0.6 µg/kg/minute); low-dose remifentanil (0.2 µg/kg/minute); or high-dose remifentanil with ketamine (remifentanil 0.6 µg/kg/minute with 0.5 mg/kg ketamine just after induction followed by an intraoperative infusion of ketamine 5 µg/kg/minute until wound closure). Fentanyl by intravenous patient-controlled analgesia was used for postoperative pain control. Visual Analog Scale pain scores and fentanyl consumption were recorded in the first 24 hours postoperatively. Perioperative serum C-reactive protein level and NLR were also determined.ResultsBaseline characteristics were similar in the three study groups. There were no between-group differences in Visual Analog Scale pain scores during the study period. The high-dose remifentanil group had a significantly higher requirement for fentanyl than the other two groups. Addition of ketamine did not affect the C-reactive protein level but increased the NLR; this increase was associated with decreased fentanyl consumption.ConclusionHigh-dose intraoperative remifentanil induced postoperative acute opioid tolerance that was prevented by infusion of low-dose ketamine. Ketamine increased the postoperative NLR associated with decreased fentanyl requirement for postoperative pain control.