Effect-site concentration of propofol required for LMA-Supreme™ insertion with and without remifentanil: a randomized controlled trial.
ABSTRACT: A new supraglottic device, the LMA-Supreme™, has recently become available for clinical use. Information on anaesthetic and co-adjuvant requirements for insertion of the LMA-Supreme™ is limited. The present study aimed to evaluate the optimal effect-site concentration of propofol in 50 % (EC50) of adults necessary for successful insertion of the LMA-Supreme™ and to examine remifentanil's effect on propofol requirements.Fifty-eight elective patients (aged 18-60 years; ASA (American Society Anaesthesiologists) physical status classification I and II) scheduled for day surgery were randomly assigned to one of two groups: propofol with saline or propofol with remifentanil. Anaesthesia was induced by target-controlled infusion according to predetermined effect-site concentrations of propofol and remifentanil (5 ng.mL(-1)). The EC50 was calculated using Dixon's up-and-down method. Ten minutes following drug administration, LMA-Supreme™ insertion was attempted without the use of muscle relaxant drugs.In the propofol + saline group, the EC50 of propofol required for LMA-Supreme™ insertion was 6.32 ± 0.67 ?g.mL(-1) (95 % CI, 5.69-6.94 ?g.mL(-1)). With the addition of remifentanil at an effect-site concentration of 5 ng.mL(-1), the EC50 of propofol required for LMA-Supreme™ insertion was 2.50 ± 0.80 ?g.mL(-1) (95 % CI, 1.82-3.17 ?g.mL(-1); p < 0.0001).The propofol requirement for smooth insertion of the LMA-Supreme™ was 60 % less when remifentanil (5 ng.mL(-1)) was co-administered.Identified as NCT01974648 at www.clinicaltrials.gov .
Project description:<h4>Background and objective</h4>Conflicting results were found between the I-gel™ and the LMA-Supreme™ during anesthesia, so we conducted a meta-analysis of randomized controlled trials (RCTs) to compare the effectiveness and safety of the I-gel™ vs. the LMA-Supreme™during anesthesia.<h4>Methods</h4>A comprehensive search was conducted using Pubmed, EMbase, ISI Web of Knowledge, the Cochrane Library, China Journal Full-text Database, Chinese Biomedical Database, Chinese Scientific Journals Full-text Database, CMA Digital Periodicals, and Google scholar to find RCTs that compare the LMA-S™ with the i-gel™during anesthesia. Two reviewers independently selected trials, extracted data, and assessed the methodological qualities and evidence levels. Data were analyzed by RevMan 5.0 and comprehensive meta-analysis software.<h4>Results</h4>Ten RCTs were included. There were no significant differences in oropharyngeal leak pressures (mean difference [MD] 0.72, 95% confidence interval [CI] -1.10 2.53), device placement time (MD -1.3, 95%CI -4.07 1.44), first attempt insertion success (risk ratio [RR] 1.01, 95% CI 0.9 1.14), grade 3 and 4 fiberoptic view (RR 0.89, 95%CI 0.65 1.21), and blood on removal (RR 0.62, 95%CI 0.32 1.22) between the i-gel™ and the LMA-Supreme™, respectively. However, the LMA-Supreme™was associated with easier gastric tube insertion (RR 1.17, 95%CI 1.07 1.29), and more sore throat (RR 2.56, 95%CI 1.60 4.12) than the i-gel™ group.<h4>Conclusions</h4>The LMA-Supreme™ and i-gel™ were similarly successful and rapidly inserted. However, the LMA-Supreme™ was shown to be easier for gastric tube insertion and associated with more sore throat compared with the i-gel™.
Project description:Supraglottic airway devices (SGA) are commonly used in pediatric anesthesia and serve as primary or back-up devices for difficult airway management. Most SGA are marketed without proper clinical evaluation. The purpose of this study was to evaluate the performance of the pediatric LMA Supreme™, Air-Q® and Ambu® Aura-i™.This prospective observational study was performed at Bern University Hospital, Switzerland. With ethics committee approval and a waiver for written informed consent 240 children undergoing elective surgery with an ASA class I-III and a weight of 5-30 kg were included. Three different pediatric supraglottic airway devices were assessed: The LMA Supreme™, Air-Q® and Ambu® Aura-i™. Primary outcome parameter was airway leak pressure. Secondary outcome parameters included first attempt and overall success rate, insertion time, fiberoptic view through the SGA, and adverse events. The primary hypothesis was that the mean airway leak pressure of each tested SGA was 20 cmH2O ± 10%.None of the SGA showed a mean airway leak pressure of 20 cmH2O ± 10%, but mean airway leak pressures differed significantly between devices [LMA Supreme™ 18.0 (3.4) cmH2O, Air-Q® 15.9 (3.2) cmH2O, Ambu® Aura-i™ 17.3 (3.7) cmH2O, p < 0.001]. First attempt success rates (LMA Supreme™ 100%, Air-Q® 90%, Ambu® Aura-i™ 91%, p = 0.02) and overall success rates (LMA Supreme™ 100%, Air-Q® 91%, Ambu® Aura-i™ 95%, p = 0.02) also differed significantly. Insertion times ranged from 20 (7) seconds (Air-Q®) to 24 (6) seconds (LMA Supreme™, <p = 0.005). Insertion was rated easiest with the LMA Supreme™ (very easy in 97% vs. Air-Q® 70%, Ambu® Aura-i™ 72%, p < 0.001). Fiberoptic view was similar between the SGA. Adverse events were rare.Airway leak pressures ranged from 16 to 18 cmH2O, enabling positive pressure ventilation with all successful SGA. The highest success rates were achieved by the LMA Supreme™, which was also rated easiest to insert.ClinicalTrials.gov , identifier NCT01625858 . Registered 31 May 2012.
Project description:The Supreme™ and ProSeal™ laryngeal mask airways (LMAs) are widely used in paediatric anaesthesia; however, LMA use in infants is limited because many anaesthesiologists prefer to use tracheal intubation in infants. In this study, we compared the Supreme and ProSeal LMAs in infants by measuring their performance characteristics, including insertion features, ventilation parameters, induced changes in haemodynamics and rates of postoperative complications.Infants of ASA physical status I scheduled for elective, minor, lower abdominal surgery were divided into two groups: the Supreme LMA group and the ProSeal LMA group. Times and ease of LMA insertion were noted. The percentages of tidal volume leakage as well as peak, mean and leakage pressures for all infants were measured. Heart rate (HR), oxygen saturation (SpO2) and end tidal carbon dioxide (EtCO2) values were recorded before and after LMA insertion and before and after extubation. After extubation, complications and adverse effects were noted.Demographic and surgical data were similar between the two groups. LMA insertion times were shorter for the ProSeal group than for the Supreme group (P?<?0.002). The mean HR value for the ProSeal group was lower than for the Supreme group (P?<?0.011). Both the peak pressure and the leakage percentage for the ProSeal group were statistically lower than for the Supreme group. The leakage pressure for the ProSeal group was statistically higher than for the Supreme group (P?<?0.001).The ProSeal LMA is superior to the Supreme LMA for use in infants due to the ease of insertion, high oropharyngeal leakage pressure and fewer induced changes in haemodynamics.ClinicalTrial.gov, NCT03251105 , retrospectively registered on 15 Aug 2017.
Project description:BACKGROUND:ProSeal (PLMA) and Supreme (SLMA) laryngeal mask airways are effective ventilator devices with distinctive designs that may require different anaesthetics for insertion. Sevoflurane induction provides acceptable conditions for laryngeal mask insertion, and remifentanil significantly decreases the minimum alveolar concentration of sevoflurane required for that insertion. The study aimed to evaluate the optimal end-tidal (ET) sevoflurane concentration for successful insertion of PLMA versus SLMA in patients receiving a remifentanil infusion without a neuromuscular blocking agent. METHODS:Altogether, 45 patients ASA (American Society Anaesthesiologists) physical status I-II, aged 18-60?years were scheduled for elective ambulatory surgery. Exclusion criteria were a difficult airway, recent respiratory infection, reactive airway, obstructive sleep apnoea syndrome, gastric aspiration's risk factors, pregnancy, and lactation. Patients were randomly allocated to receive the SLMA or the PLMA. Sevoflurane induction with co-administration of remifentanil was performed at an effect-site concentration of 4?ng?mL-?1. ET50 was calculated with a modified Dixon's up-and-down method (starting at 2.5% in steps of 0.5%). Predetermined sevoflurane concentration was kept constant during the 10?min before LMA insertion. Patient's response to LMA insertion was classified as "movement" or "no movement". Sevoflurane ET50 was determined as the midpoint concentration of all the independent pairs that manifested crossover from "movement" to "no movement". RESULTS:The ET50 sevoflurane concentration co-administered with remifentanil required for PLMA insertion was 1.20?±?0.41% (95% confidence interval 0.76 to 1.63%). For SLMA insertion, it was 0.55?±?0.38% (95% confidence interval 0.14 to 0.95%) (p =?0.019). CONCLUSIONS:The end-tidal sevoflurane concentration with co-administered remifentanil required to allow insertion of the SLMA was 54% lower than that needed for inserting the PLMA. TRIAL REGISTRATION:Clinicaltrials.gov identifier: NCT03003377. Retrospectively registered. Date of registration: December 28, 2016.
Project description:BACKGROUND:There are scenarios where pre-mixing and infusing analgesic and anaesthetic agents as a single intravenous (IV) solution is highly desirable; however, it is important to ensure the agents are compatible when mixed. As such, the long-term stability of a remifentanil-propofol mixture, and means of improving this, were assessed across a range of remifentanil concentrations, diluents, and time points. METHODS:Remifentanil was reconstituted with ultrapure water, 0.9% saline, 20% saline, or 8.4% sodium bicarbonate solution (the latter two chosen for their pH characteristics, rather than their use in pharmaceutical reconstitution) and then mixed with propofol (1%) or further diluted with water to derive concentrations of 10-50??g?mL-?1. Remifentanil and propofol concentrations were determined initially and then periodically for up to 24?h using high performance liquid chromatography (HPLC). Mass spectrometry (MS) was used to detect degradation products in solutions containing 30??g?mL-?1 of remifentanil. Statistical analysis was performed using ANOVA and Student's t-test, with a significance value of 0.05. RESULTS:Isolated remifentanil (pH <?4) and propofol (pH?7.35) did not degrade significantly when reconstituted with water or saline solution over 24?h, while remifentanil reconstituted with sodium bicarbonate degraded significantly (P <?0.001, pH?8.65). Mixing with propofol substantially increased the pH of the mixture and resulted in significant remifentanil degradation for all reconstitution solutions used, while propofol remained stable (pH?6.50). The amount of degradation product detected in samples containing isolated remifentanil and a mixture of the drugs was proportional to the remifentanil degradation observed. CONCLUSIONS:Remifentanil stability is affected by both the reconstitution solution used and when mixed with propofol, with pH appearing to be a contributing factor to degradation. If the pH of the solution and concentration of remifentanil are correctly controlled, e.g. through the use of a more acidic diluent, an admixture of remifentanil and propofol may be useful clinically.
Project description:BACKGROUND:In the present study, we compare the LMA-Protector™ and the i-gel™ in terms of adequacy of the airway seal, insertion time, ease and accuracy of insertion, and the incidence of postoperative sore throat. METHODS:In 110 anesthetized and paralyzed adult patients, the i-gel™ (n?=?55) or the LMA-Protector™ (n?=?55) was inserted. The primary outcome was airway leak pressure. The secondary outcomes included the first-attempt success rate, insertion time, ease and accuracy of the device insertion, ease of gastric tube placement, blood staining on the device after removal, and incidence and severity of postoperative sore throat. RESULTS:The airway leak pressure was higher with the LMA-Protector™ than with the i-gel™ (31  cmH2O vs. 27  cmH2O, respectively; P?=?0.016). Insertion time was longer with the LMA-Protector™ than with the i-gel™ (27  sec vs. 19  sec, respectively, P?<?0.001), but ease of insertion and the first-attempt success rate were not different between the two groups. The LMA-Protector™ provided a worse fiberoptic view of the vocal cords and more difficult gastric tube insertion than the i-gel™ (both P?<?0.001). Blood staining on the device was more frequent with the LMA-Protector™ than with the i-gel™ (P?=?0.033). The incidence and severity of postoperative sore throat were not different between the two groups. CONCLUSION:The LMA-Protector™ provided a better airway sealing effect than the i-gel™. However, it required a longer insertion time, provided a worse fiberoptic view of the vocal cords, and caused more mucosal injury compared to the i-gel™. TRIAL REGISTRATION:ClinicalTrials.gov (NCT03078517). Registered prior to patient enrollment, Date of registration: Mar 13, 2017.
Project description:Propofol is associated with pain during injection, which is stressful to patients. The present study was designed to investigate the analgesic effect of pretreatment with remifentanil and esmolol in minimizing propofol injection pain, compared with placebo.In a randomized, double-blind, prospective trial, 120 patients, scheduled for elective dental surgery under general anesthesia, were randomized to 1 of the 4 treatment arms (n = 30 each) receiving normal saline, remifentanil 0.35 μg/kg, esmolol 0.5 mg/kg, and 1 mg/kg before administration of propofol. During injection of 1% propofol 0.5 mg/kg, pain was evaluated by a 4-point score (0 = none, 1 = mild, 2 = moderate, 3 = severe). Any adverse effects such as hypotension and bradycardia were recorded during the perioperative periods.In all, 120 patients completed this study. There were no significant differences in terms of demographic data. The incidence of pain on injection of propofol was 11 (36.7%) with remifentanil 0.35 μg/kg, 12 (40%) with esmolol 0.5 mg/kg, and 11 (36.7%) with esmolol 1 mg/kg, compared with 25 (83.3%) with normal saline (respectively, P < 0.05). There were no significant differences in the incidence of pain between groups with remifentanil 0.35 μg/kg, and esmolol 0.5 mg/kg and 1 mg/kg. There were no emergence reactions such as hypotension and bradycardia in all groups.Pretreatment with esmolol 0.5 mg/kg and 1 mg/kg and remifentanil 0.35 μg/kg equally decreased pain during propofol injection.
Project description:BACKGROUND:Avoidance of airway complications and rapid emergence from anaesthesia are indispensable for the use of a laryngeal mask airway (LMA). Evidence from adequately powered randomised studies with a low risk of bias for the optimal anaesthetic in this context is limited. OBJECTIVE:We tested the hypothesis that when using remifentanil-based intra-operative analgesia, desflurane would be the most suitable anaesthetic: with noninferiority in the occurrence of upper airway complications and superiority in emergence times compared with sevoflurane or propofol. DESIGN:A randomised, multicentre, partially double-blinded, three-arm, parallel-group study. SETTING:Two university and two regional German hospitals, from February to October 2015. PATIENTS:A total of 352 patients (age 18 to 75 years, ASA physical status I to III, BMI less than 35?kg?m and fluent in German) were enrolled in this study. All surgery was elective with a duration of 0.5 to 2?h, and general anaesthesia with a LMA was feasible. INTERVENTION:The patients were randomised to receive desflurane, sevoflurane or propofol anaesthesia. MAIN OUTCOME MEASURES:This study was powered for the primary outcome 'time to state date of birth' and the secondary outcome 'intra-operative cough'. Time to emergence from anaesthesia and the incidence of upper airway complications were assessed on the day of surgery. RESULTS:The primary outcome was analysed for 343 patients: desflurane (n=114), sevoflurane (n=111) and propofol (n=118). The desflurane group had the fastest emergence. The mean (± SD) times to state the date of birth following desflurane, sevoflurane and propofol were 8.1?±?3.6, 10.1?±?4.0 and 9.8?±?5.1?min, respectively (P?<?0.01). There was no difference in upper airway complications (cough and laryngospasm) across the groups, but these complications were less frequent than in previous studies. CONCLUSION:When using a remifentanil infusion for intra-operative analgesia in association with a LMA, desflurane was associated with a significantly faster emergence and noninferiority in the incidence of intra-operative cough than either sevoflurane or Propofol. TRIAL REGISTRATION:ClinicalTrials.gov identifier: NCT02322502; EudraCT identifier: 2014-003810-96.
Project description:Objective To investigate the effect-site concentration of remifentanil required to blunt haemodynamic responses during tracheal intubation with a single-lumen tube (SLT) or a double-lumen tube (DLT). Methods Patients scheduled for thoracic surgery requiring one-lung ventilation were randomly allocated to either the SLT or DLT group. All patients received a target-controlled infusion of propofol and a predetermined concentration of remifentanil. Haemodynamic parameters during intubation were recorded. The effect-site concentration of remifentanil was determined using a delayed up-and-down sequential allocation method. Results A total of 92 patients were enrolled in the study. The effective effect-site concentrations of remifentanil required to blunt haemodynamic responses in 50% of patients (EC50) estimated by isotonic regression with bootstrapping was higher in the DLT than the SLT group (8.5 ng/ml [95% confidence interval (CI) 8.0-9.5 ng/ml] versus 6.5 ng/ml [95% CI 5.6-6.7 ng/ml], respectively). Similarly, the effective effect-site concentrations of remifentanil in 95% of patients in the DLT group was higher than the SLT group (9.9 ng/ml [95% CI 9.8-10.0 ng/ml] versus 7.0 ng/ml [95% CI 6.9-7.0 ng/ml], respectively). Conclusions This study demonstrated that a DLT requires a 30% higher EC50 of remifentanil than does an SLT to blunt haemodynamic responses during tracheal intubation when combined with a target-controlled infusion of propofol. Trial registration Clinicaltrials.gov identifier: NCT01542099.
Project description:We evaluated the efficacy of an alternative technique, for insertion of the silicone laryngeal mask airway (LMA) Classic™ in 40 American Society of Anesthesiologists grade ASA I and II patients scheduled for elective surgery. In group I (Index Finger group), the LMA was inserted by the classic index finger technique and, in group T (Thumb Insertion group), the thumb insertion technique was used. Ease of insertion, fiberoptic laryngoscopic position, cuff pressures and laryngopharyngeal morbidity were assessed in both study groups. On statistical analysis, both groups were comparable in all respects. From our study it can be concluded that thumb insertion is an effective insertion technique for the LMA Classic™.