Target-controlled Infusion Of Remifentanil Research Articles

Effective bolus dose of remimazolam for i-gel® insertion in nonparalyzed patients: a dose-finding study

PurposeRemimazolam is a recently developed ultra-short-acting benzodiazepine used for anesthesia induction and maintenance. Nevertheless, the effective bolus dose of remimazolam for i-gel® (Intersurgical Ltd., Wokingham, Berkshire, UK) insertion without the use of neuromuscular blocking agents (NMBAs) has not been well established.MethodsThis study included 25 adult patients scheduled for surgery under general anesthesia who were eligible for i-gel use. Anesthesia was induced with predetermined bolus doses of remimazolam, starting at 0.3 mg·kg−1 for the first patient, without the use of NMBAs. All patients concurrently received remifentanil using target-controlled infusion (TCI) at a fixed effect-site concentration (Ce) of 3.0 ng·mL−1. Insertion of the i-gel was attempted 90 sec after remimazolam administration, and insertion conditions were assessed. Subsequent doses of remimazolam were decreased or increased by 0.05 mg·kg−1, depending on the success or failure of i-gel insertion.ResultsThe mean (standard deviation) 50% effective dose (ED50) of a remimazolam bolus for successful i-gel insertion as determined by the modified Dixon’s up-and-down method was 0.100 (0.027) mg·kg−1. The ED50 and ED95 estimated by isotonic regression were 0.111 (83% confidence interval [CI], 0.096 to 0.131) mg·kg−1 and 0.182 (95% CI, 0.144 to 0.195) mg·kg−1, respectively. None of the patients required treatment for hypotension or bradycardia during anesthesia induction.ConclusionBased on the ED95 of remimazolam bolus dose determined in our study, we recommend using 0.182 mg·kg−1 of remimazolam in combination with remifentanil TCI at a Ce of 3.0 ng·mL−1 for successful i-gel insertion without NMBAs in adult patients. This regimen seems effective with a low risk of hemodynamic instability during anesthesia induction.Study registrationClinicalTrials.gov (NCT05298228); first submitted 6 March 2022.

Effect of target-controlled infusion of remifentanil in combination with propofol on anesthesia and endotracheal intubation response in patients undergoing surgical aneurysm clipping

Purpose: To investigate the effect of target-controlled infusion of remifentanil in combination with propofol on anesthesia and endotracheal intubation response in patients undergoing surgical aneurysm clipping. 
 Methods: The clinical data of 106 patients undergoing surgical aneurysm clipping at the Central Hospital of Wuhan, Wuhan City, China from September 2020 to December 2022 were retrospectively analyzed. Subjects in control group were given fentanyl intravenous infusion anesthesia while study group was treated with target-controlled infusion anesthesia of remifentanil combined with propofol. Hemodynamics and blood-gas indices were evaluated before anesthesia (T1), immediately after endotracheal intubation (T2) and at extubation (T3). The incidence of anesthesia-related complications was determined. 
 Results: In study group, the agitation score was decreased compared to that of control group, while the Ramsay sedation score was increased (p < 0.05). The incidence of cough during endotracheal catheter indwelling and extubation was 7. 27 % in study group, which was less than 21. 57 % in control group (p < 0.05). The cough score of study group was also reduced (p < 0.05). There were no significant differences in the SpO2 and PetCO2 values between the two groups at different times (p > 0.05). Furthermore, the mean arterial pressure at T2 and T3 was upregulated and heart rate (HR) was downregulated in study group (p < 0.05). Recovery time of spontaneous respiration, time of eye-opening and extubation in study group were decreased compared to control group (p < 0.05). 
 Conclusion: Target-controlled infusion of remifentanil in combination with propofol improves anesthetic effect in patients undergoing surgical aneurysm clipping, reduces tracheal intubation reaction, maintains hemodynamic stability and improves recovery quality of patients. Future study will be required to evaluate the efficacy and optimal effective concentration in a diverse population.

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

BackgroundEvery 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 presentationWe 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 conclusionTo 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.

Multimodal prevention of emergence cough following nasal endoscopic surgery under general anesthesia: a double-blind randomized trial.

Cough during emergence from anesthesia is a common problem and may cause adverse events. Monotherapy faces uncertainty in preventing emergence cough due to individual differences. We aimed to evaluate the efficacy and safety of multimodal intervention for preventing emergence cough in patients following nasal endoscopic surgery. In this double-blind randomized trial, 150 adult patients undergoing nasal endoscopic surgery were randomly allocated into three groups. For the control group (n = 50), anesthesia was performed according to clinical routine, no intervention was provided. For the double intervention group (n = 50), normal saline 3 mL was sprayed endotracheally before intubation, 0.4 μg/kg dexmedetomidine was infused over 10 min after intubation, and target-controlled remifentanil infusion was maintained at an effect-site concentration of 1.5 ng/mL before extubation after surgery. For the multimodal intervention group (n = 50), 0.5% ropivacaine 3 mL was sprayed endotracheally before intubation, dexmedetomidine and remifentanil were administered as those in the double intervention group. The primary endpoint was the incidence of emergence cough, defined as single cough or more from end of surgery to 5 min after extubation. The incidences of emergence cough were 98% (49/50) in the control group, 90% (45/50) in the double group, and 70% (35/50) in the multimodal group, respectively. The incidence was significantly lower in the multimodal group than those in the control (relative risk 0.71; 95% CI 0.59 to 0.86; p < 0.001) and double (relative risk 0.78; 95% CI 0.63 to 0.95; p = 0.012) groups; the difference between the double and control groups was not statistically significant (relative risk 0.92; 95% CI 0.83 to 1.02; p = 0.20). The severity of sore throat was significantly lower in the multimodal group than that in the control group (median difference-1; 95% CI -2 to 0; p = 0.016). Adverse events did not differ among the three groups. For adult patients undergoing endonasal surgery, multimodal intervention including ropivacaine topical anesthesia before intubation, dexmedetomidine administration after intubation, and remifentanil infusion before extubation after surgery significantly reduced emergence cough and was safe.

Dental Sedation with Propofol-based Target Controlled Infusions: Changing Sedation Patterns and Our Current Approach after 2800 Office-based Procedures

We describe the changing patterns of our office-based dental sedation technique over the past 5 years, based on the cumulative experience gained from treating 2800 patients. We also report the changing rate over time of minor, clinically insignificant adverse events based on a recent 652-patient audit of our office-based intravenous sedation (IVS). Our current preference, with most patients, is to administer a combination of propofol via a Target Controlled Infusion (TCI) in combination with TCI remifentanil. The rationale and reasons for this and the progressively changing doses of intravenous (IV) agents are discussed. Our office-based TCI IVS technique affords patient safety, high satisfaction rates and much faster discharge times in comparison with discharge times from mainstream hospitals. The surgeons are provided with greater scheduling flexibility plus the ability to operate in their own office with familiar staff.

"The Impact of Different Dosages of Oxycodone on the Incidence of Cough Reflex During Target-Controlled Infusion of Remifentanil: A Single-Center Randomized Controlled Clinical Trial"

"The Impact of Different Dosages of Oxycodone on the Incidence of Cough Reflex During Target-Controlled Infusion of Remifentanil: A Single-Center Randomized Controlled Clinical Trial"

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

BackgroundThe 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.MethodsNinety-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.ResultsThere 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.ConclusionIntraoperative use of remifentanil as an adjuvant in AIS patients undergoing posterior spinal fusion surgery was not associated with postoperative hyperalgesia.

Prolonged Anesthesia Induction to Delivery Time Did Not Influence Plasma Remifentanil Concentration in Neonates.

Remifentanil, in combination with etomidate and sevoflurane, is commonly used in clinics for general anesthesia induction in cesarean section (CS). This study aimed to evaluate the correlation between the induction to delivery (I-D) time and neonatal plasma drug concentration and anesthesia, as well as its effects on neonates. Fifty-two parturients in whom general anesthesia was induced for CS were divided into group A (I-D<8 min) and group B (I-D≥8 min). Maternal arterial (MA), umbilical venous (UV), and umbilical arterial (UA) blood samples were collected at delivery to analyze the remifentanil and etomidate concentrations using liquid chromatography-tandem mass spectrometry. There were no statistically significant differences between the two groups in terms of plasma concentrations of remifentanil in the MA, UA, and UV blood (P > 0.05). The plasma concentration of etomidate in MA and UV was higher in group A than that in group B (P<0.05), whereas the UA/UV ratio of etomidate was higher in group B than that in group A (P<0.05). The Spearman rank correlation test showed no correlation between the I-D time and plasma remifentanil concentration in the MA, UA, and UV plasma (P>0.05). The concentrations of etomidate in the MA and UV were negatively correlated with the I-D time (P < 0.05). Prolonged I-D time did not significantly influence the maternal or neonatal plasma concentration of remifentanil. It is safe to administer remifentanil target-controlled infusion in combination with etomidate and sevoflurane for general anesthesia induction during CS.

Comparison of bispectral index and phase lag entropy during general anesthesia: Sevoflurane or propofol anesthesia.

Phase-lag entropy (PLE) based on functional connectivity between different regions of the brain may be superior to conventional depth of anesthesia (DoA) methods for monitoring changes in consciousness. However, few studies have compared the PLE and bispectral index (BIS) methods for monitoring consciousness during clinical anesthesia, such as total intravenous anesthesia (TIVA) or anesthesia via inhalation. Therefore, we evaluated differences between the PLE and BIS methods in clinical anesthesia, including TIVA using propofol and anesthesia with sevoflurane. The observational trial included 60 patients scheduled for elective surgery under general anesthesia. The BIS and PLE electrodes were placed together on the left temporal-frontal area of all patients. During anesthesia, anesthetic levels were adjusted using the BIS values, which are generally used to monitor the DoA; the level of anesthesia was maintained at between 40 and 60. BIS- and PLE-derived values were recorded continuously. Anesthetic events, the concentration of each anesthetic, and standard monitoring values were recorded. The patients included were divided into 2 groups, the TIVA and sevoflurane groups, with 30 patients in each. For the TIVA group, anesthesia was induced and maintained using propofol and remifentanil target-controlled infusion. For the sevoflurane group, anesthesia was induced using propofol and maintained using sevoflurane and remifentanil. From loss of consciousness until the anesthetic maintenance period, PLE values were higher than BIS values at several time points. During the recovery period, BIS values were higher than PLE values (all P < .001). Spaghetti plots showed that there was more variation among the BIS values than among the PLE values. For monitoring DoA during general anesthesia and surgery, PLE values vary less than BIS values; thus, PLE may be more reliable for monitoring changes in consciousness. However, further studies are needed to evaluate the clinical application of these methods in general anesthesia.

Inhibition of stress and spontaneous respiration: Efficacy and safety of monitored anesthesia care by target-controlled infusion remifentanil in combination with dexmedetomidine in fibreoptic bronchoscopy for patients with severe tracheal stenosis.

This study aimed to determine the effective concentration of target-controlled infusion (TCI) of remifentanil used to inhibit stress during the treatment of severe tracheal stenosis with fibreoptic bronchoscopy and to evaluate the monitored anesthesia care (MAC) by remifentanil. 60 patients with severe tracheal stenosis who underwent fibreoptic bronchoscopy was performed. Dexmedetomidine was initially administered at a bolus dose (0.8 mcg/kg), followed by a 0.5 mcg/(kg⋅h) continuous infusion. Remifentanil was administered by TCI. The effective concentration (EC) of remifentanil was titrated by the improved sequential method, and 30 patients were included. The EC95 of remifentanil was set as the plasma target concentration to evaluate the safety of the MAC, and another 30 patients were included. The half effective effect-chamber concentration of remifentanil (EC50) was 2.243 ng/ml, and the EC95 was 2.710 ng/ml. Among the 30 patients who received an EC95 of remifentanil as the target concentration, one patient was remedied by injecting propofol, the score of Ramsay sedation was three. The incidence of subclinical hypoxemia (SPO2 of 90-95%) was 30%, the incidence of moderate hypoxemia (SPO2 of 75-89%, ≤60 s) was 20 and 86.7% of patients with oxygen saturation was less than 95% returned to normal by awakening. The satisfaction score of the operator was nine, the satisfaction score of the anesthesiologist was eight, the satisfaction score of the patients was 10, the rate of patient willingness to re-accept the procedure was 93.3% and the circulation was stable during the operation. MAC using TCI of remifentanil with continuous pumping dexmedetomidine can effectively inhibit the stress response to fibreoptic bronchoscopy in patients with severe tracheal stenosis while maintaining spontaneous breathing. Under the anesthesia management of an experienced anesthesiologist, it provides a reference to tracheoscopic anesthesia of autonomous breathing. [http://www.chictr.org.cn/], identifier [ChiCTR 2100043380].

Adding Low-Dose Propofol to Limit Anxiety during Target-Controlled Infusion of Remifentanil for Gastrointestinal Endoscopy: Respiratory Issues and Safety Recommendations.

Backgroundand Objectives: Remifentanil-based sedation is one of many protocols proposed for endoscopy procedures in spontaneous ventilation, alone or in combination with propofol. However, the effect of these small doses of propofol on the efficacy and safety of remifentanil target-controlled infusion (TCI) deserves to be examined in this context. The objective of this study was to assess the adverse respiratory and cardiovascular effects of small boluses of propofol combined with remifentanil, in comparison with remifentanil alone, and balanced with the quality of sedation and recovery. Materials andMethods: This was an observational bicenter study, representing a subgroup of a larger study describing remifentanil-based procedural sedation. In center 1, patients scheduled for gastrointestinal (GI) endoscopy had remifentanil TCI alone. In center 2, patients had a 10 mg propofol bolus before TCI and other boluses were allowed during the procedure. Remifentanil TCI was started at a target of 2 ng/mL then adapted by 0.5 ng/mL steps according to patient response to endoscopy stimulations. Results: Center 1 included 29 patients, while center 2 included 60 patients. No difference was found in the patients’ characteristics, incidence of success, average remifentanil consumption, or cardiovascular variables. Light sedation was achieved when propofol was added. The incidence of respiratory events, such as bradypnea, desaturation < 90%, and apnea requiring rescue maneuvers, were significantly higher with propofol. Conclusions: Adding propofol boluses to a remifentanil TCI for GI endoscopy ensures light sedation that may be necessary for anxiolysis but increases respiratory events, even after administration of small-dose boluses. Its safety is acceptable if the procedure is performed in an equipped environment with sedation providers trained to manage respiratory events and drugs titrated to minimal doses.

Comparison of 2 effect-site concentrations of remifentanil with midazolam during transrectal ultrasound-guided prostate biopsy under procedural analgesia and sedation: A randomized controlled study.

Until now, target-controlled infusion of remifentanil with midazolam for transrectal ultrasound-guided prostate biopsy has not been described. Here, we investigate 2 effect-site concentrations of remifentanil with intermittent bolus midazolam for transrectal ultrasound-guided prostate biopsy under procedural analgesia and sedation. A prospective, randomized controlled trial including patients who received a transrectal ultrasound-guided prostate biopsy between February 2019 and January 2021 was conducted. Group 1 and Group 2 were respectively administered an initial effect-site concentration of remifentanil of 1.0 ng/mL and 2.0 ng/mL by a target-controlled infusion pump with Minto model. In both groups, maintenance of the effect-site concentration of remifentanil was adjusted upward and downward by 0.5 ng/mL to keep patient comfort with acceptable pain (remaining moveless), and mean arterial pressure and heart rate within baseline levels ± 30%, and using intermittent bolus midazolam to keep the Observer's Assessment of Alertness/Sedation scale between 2 and 4. The primary outcome was to determine which effect-site concentration of remifentanil provide adequate patient comfort with acceptable pain (remaining moveless) during the procedure. A total of 40 patients in Group 1 and 40 patients in Group 2 were eligible for analysis. Most parameters were insignificantly different between Group 1 and Group 2, except Group 1 having higher peripheral oxygen saturation while probe insertion compared with Group 2. Group 2 patients had less intraoperative movements affecting the procedure (2 vs 18; P < .001), and less total times of target-controlled infusion pump adjustment (0 [0-1] vs 1 [0-3], P < .001) compared with group 1. However, group 1 patients had less apnea with desaturation (peripheral oxygen saturation < 90%; 0 vs 9, P = .002) and less remifentanil consumption (94.9 ± 25.5 μg vs 106.2 ± 21.2 μg, P = .034) compared to Group 2. In transrectal ultrasound-guided prostate biopsy, target-controlled infusion with remifentanil Minto model target 2.0 ng/mL with 3 to 4 mg midazolam use provided sufficient analgesia and sedation, and appropriate hemodynamic and respiratory conditions.

Sufentanil target controlled infusion (TCI) versus remifentanil TCI for monitored anaesthesia care for patients with severe tracheal stenosis undergoing fiberoptic bronchoscopy: protocol for a prospective, randomised, controlled study

IntroductionThe use of monitored anaesthesia care (MAC) is necessary and ubiquitous for fiberoptic bronchoscopy. Anaesthetic management of patients with severe tracheal stenosis has always been a challenge. The efficacy and...

A Comparison of the Effects of Prolonged Infusion of Propofol 2% and 1% During Total Intravenous Anaesthesia Using Target-Controlled Infusion Technique for Elective Neurosurgery.

BackgroundTotal intravenous anaesthesia (TIVA) with a combination of target-controlled infusions (TCIs) of propofol and remifentanil has been advocated for a favourable neurosurgical outcome. Neurosurgical procedures often involve a prolonged duration and large cumulative infusion of propofol. This study compares the serial serum lipid profile, acid-base balance and lactate level of neurosurgical patients anaesthetised with TCIs of propofol at 2% versus 1%.MethodsA total of 74 patients who underwent an elective craniotomy under general anaesthesia were randomised into two groups: i) propofol 1% (n = 37) and ii) propofol 2% (n = 37). All patients were anaesthetised using TCIs of propofol and remifentanil. Serial lipid profiles (serum triglyceride [TG] and cholesterol levels) were taken at the baseline, upon cessation of propofol and at 2 h post-operation. The total dosage, volume used and syringe changes of both groups were also documented.ResultsThe total volume of propofol used was significantly lower in the 2% group than the 1% group (157.19 mL [SD = 77.14] versus 335.17 mL [SD = 174.27]; P = 0.005) and the frequency of syringe changes was also less in the 2% than the 1% group (2 [3] versus 6 [3]; P < 0.001). However, there were no significant differences between the two groups in terms of serial serum TG, cholesterol, the acid-base balance or the lactate level. There was also no significant correlation of lipid profile with cumulative dose or volume of propofol infused between the two groups.ConclusionBoth concentrations of propofol, 1% and 2%, were comparable in terms of the serial lipid profile, acid-base balance and lactate level during TIVA using TCIs for elective neurosurgery. The benefits of propofol at 2% were that a lower volume was used and there were fewer syringe changes, which could minimise anaesthesia interruption throughout surgery.

Airway management of a neurofibromatosis type 2 with multicompartmental tumours: a case report

Neurofibromatosis type 2 (NF2) is a rare autosomal dominant disorder. We report a case of a 52-year-old woman with underlying NF2 who was scheduled for excision of cervical neurofibromas. The patient had four nerve sheath tumours affecting different parts of the airway, namely, two cervical neurofibromas with spinal cord compression, a large retrosternal goitre extending into the anterior mediastinal compartment causing central airway obstruction, and a large left thoracic paravertebral tumour in the posterior mediastinal compartment. After risk stratification and multidisciplinary discussion, awake nasal fibreoptic intubation with a contingency plan of rigid bronchoscopy and jet ventilation was decided. The patient was intubated successfully with target-controlled infusion remifentanil as the sole sedative and airway topicalization with local anaesthetic. The patient was ventilated in a prone position intraoperatively with no desaturation. The tumours were successfully removed and the patient was discharged well. Awake nasal fibreoptic intubation is the choice of management in difficult airways affected by multicompartmental tumours in a centre that is devoid of extracorporeal membrane oxygenation service.

Reliability of the Minto model for target-controlled infusion of remifentanil during cardiac surgery with cardiopulmonary bypass

BackgroundThe Minto pharmacokinetic model is used for target-controlled infusion of remifentanil. The reliability of this model has never been evaluated during normothermic cardiac surgery with cardiopulmonary bypass (CPB). The aim of this study was to assess the predictive performance of the model during CPB to determine its reliability during cardiac surgery. MethodsThis was a single-centre observational study. Arterial blood samples were drawn at five time points: T1, after tracheal intubation; T2, immediately before CPB; T3, 10 min after starting CPB; T4, 45 min after starting CPB; T5, 10 min after weaning off CPB. Prediction error (PE) and absolute prediction error (APE) were calculated for each sample and used to determine median prediction error (MDPE) and median absolute prediction error (MDAPE) per patient. Risk factors for APE >30% were assessed using multivariable analysis. Results are presented as medians with inter-quartile ranges. ResultsFifty-eight patients with 283 blood samples (110 during CPB) were included. In the pre-CPB period, MDPE and MDAPE were –17.3 [–32.9 to 2.3] and 24.6 [12–37.7]%, whereas during CPB, they were –1.8 [–15.6 to 11.1] and 14.0 [6.74–27.1]%, respectively. There was no statistically significant difference between measured and predicted remifentanil plasma concentrations during CPB. Age, preoperative albumin concentrations, temperature, and haemodilution were not independently associated with MDAPE >30%. ConclusionsThe Minto model accurately predicts plasma remifentanil concentrations during cardiac surgery with CPB. Clinical trial registration2017-A03153-50.

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.

Comparison of Postoperative Recovery after Manual and Target-Controlled Infusion of Remifentanil in Bariatric Surgery.

Background and Objectives: Early postoperative recovery after surgery is a key point for patients’ safety and comfort. Moreover, operating room turnover depends on recovery time. Our aim was to assess which method of remifentanil administration, manual (MI) or target-controlled infusion (TCI), could reduce patient time in recovery room. In this study, patients’ recovery times were registered and compared among the groups. Materials and Methods: We enrolled 31 morbidly obese patients in this prospective study. All of them had undergone bariatric surgery at the Hospital of Lithuanian University of Health Sciences Kauno Klinikos in 2020. Sevoflurane/remifentanil anaesthesia was performed for all patients. The patients were randomly assigned to the manual infusion (MI) (control group) or target-controlled infusion (TCI) group for the method of the administration of remifentanil. While the patients were waking up after the surgery, we recorded spontaneous breathing and airway reflexes recovery time, time of extubation, eye opening, recovery of orientation and beginning of the following oral command. For the TCI group, we also documented remifentanil concentrations in the blood (automatic infusion pump). Results: Patients did not differ in demographic values and duration of remifentanil infusion. We found that remifentanil consumption in the TCI group was lower, p = 0.02. Despite lower remifentanil consumption in the TCI group patients, they demonstrated longer total recovery time than the control group patiens: 14 (12–20) vs. 10 (6–16), p = 0.001. Conclusions: The study showed that, upon comparing the TCI method with MI, manual infusion produced better results in postoperative patient recovery. Additionally, higher doses of remifentanil were consumed using MI. In conclusion, the dosage recommended by highly qualified anaesthesiologists is favourable for morbidly obesity patients when compared to the TCI method.

Remifentanil target-controlled infusion with intranasal dexmedetomidine for vitreoretinal procedures: a randomized controlled trial

AimTo evaluate the consumption of remifentanil (as a primary end-point), analgesia, sedation, hemodynamics, respiratory effects, and surgeon and patient satisfaction (as a secondary end-point) with dexmedetomidine sedation compared with those of remifentanil sedation in patients undergoing vitreoretinal surgery.MethodsPatients subjected to retinal ophthalmic surgical procedures were randomized to one of two intraoperative sedation groups: one group (n = 21) received intranasal dexmedetomidine plus intravenous remifentanil (DEX-REMI group), and the other group (n = 19) received intravenous remifentanil only (REM group). The treatment was placebo-controlled. The sedation level was controlled according to the bispectral index, with target values between 80%-90%. Patient levels of comfort, sedation, and pain were documented. The number of intraoperative complications and the level of satisfaction were assessed. Remifentanil consumption and hemodynamic parameters were also included in the statistical analysis.ResultsThe level of remifentanil consumption was significantly lower in the DEX-REMI group, but combination sedation improved the surgeon's, anesthesiologist's, and patients' satisfaction scores. Importantly, the number of complications was zero in the DEX-REMI group, while eight cases of complications were noted in the REM group. The DEX-REMI group showed lower mean minimal arterial pressure, but it was still in the normotensive range.ConclusionsFor patients undergoing ophthalmic procedures, sedation with a combination of intranasal dexmedetomidine and an intravenous infusion of remifentanil provides lower remifentanil consumption, better satisfaction scores, and a lower complication rate than sedation with a remifentanil infusion alone.Clinical trial numberNCT 03251222

Effects of smoking on the optimal effect-site concentration of remifentanil required for preventing cough during anesthetic emergence in male patients undergoing laparoscopic or robotic cholecystectomy.

Target-controlled infusion of remifentanil is known to reduce cough effectively during emergence from general anesthesia. The effect of smoking on emergence cough remains controversial. Therefore, we aimed to investigate the effect-site concentration (Ce) of remifentanil in the male patients undergoing laparoscopic or robotic cholecystectomy for suppressing emergence cough in smokers and non-smokers.Twenty smokers and 24 non-smokers (sex, male; age range, 20–65 years) were enrolled in this study. Anesthesia was maintained using sevoflurane and remifentanil. The Ce of remifentanil in 50% (EC50) and 95% (EC95) of the patients required for suppressing emergence cough were determined for each group (smokers and non-smokers) using Dixon up-and-down method and isotonic regression method with a bootstrapping approach.Dixon up-and-down method revealed that the EC50 value was significantly higher in smokers (3.51 ± 0.60 ng/mL) than in non-smokers (2.71 ± 0.30 ng/mL) (P < 0.001). In smokers and non-smokers, isotonic regression revealed EC50 to be 4.40 (83% CI, 4.17–4.58) ng/mL and 2.58 (83% CI, 2.31–2.87) ng/mL, respectively, and EC95 to be 4.76 (95% CI, 4.73–4.78) ng/mL and 3.15 (95% CI, 3.04–3.18) ng/mL, respectively.The Ces of remifentanil required to prevent cough during emergence were significantly higher in smokers than in non-smokers. Therefore, clinicians should pay attention to the smoking history of a patient to prevent cough during emergence.