Comparison of the clinical performance of i-gel and Ambu laryngeal masks in anaesthetised paediatric patients:A meta-analysis

BACKGROUND Paediatric supraglottic airway devices(SGAs)are widely used in routine anaesthesia and serve as primary or back-up devices for difficult airway management.The inflatable Ambu laryngeal masks and non-inflatable i-gel are two improvements of SGAs based on classic laryngeal masks.The clinical performance and safety of these two devices in paediatric patients are still unclear and warrant further investigation.AIM To perform a systematic review and meta-analysis on the clinical performance and safety of Ambu laryngeal masks and i-gel in anaesthetised paediatric patients.METHODS MEDLINE,Embase,Web of Science and Cochrane Central Register of Controlled Trials were searched from inception dates to April 2020.We identified published randomised controlled trials(RCTs)in which the intervention involved the use of Ambu laryngeal masks and i-gel in anaesthetised paediatric patients(age<18 years).We assessed the oropharyngeal leak pressure(OLP)as the primary outcome.The secondary outcomes were insertion time,success rate of insertion on the first attempt,and incidence of adverse events.RESULTS After searching for all relevant trials published up to April 2020,data from seven RCTs with a total of 667 paediatric patients(323 and 344 participants in the i-gel and Ambu groups,respectively)were evaluated.The mean OLP in anaesthetised paediatric patients was lower in the Ambu group[21.82 cmH2O for Ambu vs 23.98 cmH2O for i-gel,P=0.003,95%confidence interval(CI):-3.58 to-0.75,I2=68%,Mantel-Haenszel random model].We did not find any clear evidence of differences between the devices in terms of insertion time,success rate of insertion,and incidence of adverse events except for blood staining(risk ratio 5.86,95%CI:1.76 to 19.46,P=0.004,I2=0,fixed-effect model).CONCLUSION The i-gel airway may provide a better seal and is therefore probably more suitable than the Ambu laryngeal mask airway in anaesthetised paediatric patients.However,the evidence is insufficient to allow making firm conclusions or to guide clinical practice,owing to the small number of relevant published studies.

Shikani Optical Stylet–guided Intubation via the Intubating Laryngeal Airway in Patients With Scar Contracture of the Face and Neck

Objective To evaluate the feasibility of the Shikani Optical Stylet （SOS）-guided inmbation through a new Intubafing Laryngeal Airway （ILA） in anticipated difficult airways caused by scar contracture of the face and neck. Methods Thirty-three adult patients with anticipated difficult airways undergoing selective faciocervical scar plastic surgery under general anesthesia were enrolled in this study. After anesthesia induction, a size 2.5, 3.5 or 4.5 ILA was inserted. Following good lung ventilation being verified, the SOS preloaded with an endotracheal tube was inserted via the ILA. Once the clear vocal cords came into view under the SOS, the endotracheal tube was advanced through glottis into the trachea. Results The ILA provided an effective airway in all patients, lntubation was successful at the first attempt on 22/33 （66.7%） occasions and at the second attempt on 6/33 （18.2%）. Intubation failed in 5 （15.1%） patients who suffered from severe limitation of head extension due to scar contracture of the neck. These patients＇ tracheas were finally intubated using a fibreoptic bronchoscope via the ILA. Conclusions The SOS-guided intubating method via the ILA is a feasible technique in patients with scar contracture of the face and neck. However, in patients with severe limitation of head extension, the use of SOS cannot be recommended. The SOS can be used as an alternative apparatus when the fibreoptic bronchoscope is not available.

Total intravenous general anesthesia with laryngeal mask airway for transurethral resection of bladder tumor

Objective： To observe the advantage of total intravenous anesthesia for transurethral resection of bladder tumor （TURBT）. Methods.. Sixty ASA Ⅰ-Ⅱ patients undergoing TURBT were randomly assigned to 2 groups. Spinal anesthesia with 0. 75% pure bupivacaine （8-12 rag） was applied to patients in Group Ⅰ （n= 30）. Patients in Group Ⅱ （n=30） received total intravenous anesthesia with continuous infusion of Propofol and Remifentanil ; and a laryngeal mask was used to ensure the airway and ventilation. BP, HR, SPO2 and pertinent side effects were monitored and recorded. Results ： The patients in group Ⅱ experienced more stable hemodynamics than those in group Ⅰ . Obturator nerve reflex was observed in 15 （50. 0%） patients in Group Ⅰ , but none （0%） in Group Ⅱ （P〈0. 01）. Conclusion.. Total intravenous anesthesia with laryngeal mask is a safe, reliable, controllable and simple manual for patient undergoing TURBT.

Lingual nerve injury caused by laryngeal mask airway during percutaneous nephrolithotomy:A case report

BACKGROUND Lingual nerve injury(LNI)is a rare complication following the use of laryngeal mask airway(LMA).The occurrence of this unexpected complication causes uncomfortable symptoms in patients and worsens their quality of life.We present an unusual case of LNI caused by the use of an LMA in percutaneous nephrolithotomy(PCNL).CASE SUMMARY A 49-year-old man presented to our hospital with a 3-year history of intermittent left lower back pain.Abdominal computed tomography showed a 25 mm×20 mm stone in the left renal pelvis.PCNL surgery using LMA was performed to remove the renal stone.The patient reported numbness on the tip of his tongue after the operation,but there were no signs of swelling or trauma.The patient was diagnosed with LNI after other possible causes were ruled out.The symptom of numbness eventually improved after conservative medical therapy for 1 wk.The patient completely recovered 3 wk after surgery.CONCLUSION This is the first case report describing LNI with the use of LMA in PCNL.In our case,an inappropriate LMA size,intraoperative movement,and a specific surgical position might be potential causes of this rare complication.

Comparison of Postoperative Throat and Neck Complaints after the Use of the i-Gel versus the Traditional Laryngeal Mask

Introduction: One of the most important jobs of an anesthesiology is to preserve an adequate gaseous exchange. With the coming in the 80’s of the laryngeal mask airway, a less invasive technique was introduced for this end. There are a lot of variants of these supraglotic issues, being the i-gel a no inflate mask;witch principle is to provide a perilaryngel stamp that reduced the incidence of sore throat, cervical pain compared with the traditional laryngeal mask. Method: A group of 121 ASA I-II patients with general anesthesia administration, where divided in two groups, one of 60 patients where a traditional laryngeal mask airway was used, and a second group of 61 patients where an i-gel mask was used. In both groups the presence of postoperative sore throat, cervical pain and dysphonia;number of attempts and pressure in the airway tract was measured. Results: The group of patients where the i-gel was used present lower incidence of sore throat (11% vs 27%) and cervical pain (3% vs 9%) and lower values of pressure on the airway tract compared with the group in which the conventional laryngeal mask was used. On the other hand there was no difference in the presence of dysphonia, trauma or number of attempts used to insert the mask. Conclusions: The i-gel larygeal mask demonstrated to be a safe issue, with low incidence of morbidity to administrated general anesthesia.

Severe gastric insufflation and consequent atelectasis caused by gas leakage using AIR-Q laryngeal mask airway:A case report

BACKGROUND The airways of patients undergoing awake craniotomy(AC)are considered“predicted difficult airways”,inclined to be managed with supraglottic airway devices(SADs)to lower the risk of coughing or gagging.However,the special requirements of AC in the head and neck position may deteriorate SADs’seal performance,which increases the risks of ventilation failure,severe gastric insufflation,regurgitation,and aspiration.CASE SUMMARY A 41-year-old man scheduled for AC with the asleep–awake–asleep approach was anesthetized and ventilated with a size 3.5 AIR-Q intubating laryngeal mask airway(LMA).Air leak was noticed with adequate ventilation after head rotation for allowing scalp blockage.Twenty-five minutes later,the LMA was replaced by an endotracheal tube because of a change in the surgical plan.After surgery,the patient consistently showed low tidal volume and was diagnosed with gastric insufflation and atelectasis using computed tomography.CONCLUSION This case highlights head rotation may cause gas leakage,severe gastric insufflation,and consequent atelectasis during ventilation with an AIR-Q intubating laryngeal airway.

The effect of different inflation volumes of laryngeal mask airway on efficacy of closed circuit controlled ventilation in pediatric cancer patients

Objective： The laryngeal mask airway （LMA） is an established way for airway control during spontaneous ventila- tion. Its ability to deliver positive pressure ventilation without leakage especially in low flow states is still controversy. The aim of this study is to test the possibility of using LMA in pediatric closed circuit controlled ventilation, and to find out the optimum cuff volume to perform closed system ventilation. Methods： Twenty children scheduled for elective surgeries were enrolled in a crossover study. Laryngeal mask airway was used. In stage I, the cuff was inflated with the maximum volume of air as rec- ommended by the manufacturers. Adjustment of volume of air inflated into the LMA cuff to the minimum volume to obtain the effective seal was done at stage II. The leak pressure, intracuff pressure and the leak volume were measured in both stages. Results： The cuff filling volume was significantly lower compared to the maximum cuff inflation volume in stage I. Leakage values showed significantly less values in stage II of the study with smaller cuff inflation volumes. The airway leakage pressure was significantly lower in stage fl in comparison to stage I. Cuff inflation pressure in stage I showed marked elevation which dropped significantly after adjustment of cuff volume in stage I1. Conclusion： Laryngeal mask airway is an effective tool to provide closed circuit controlled ventilation in pediatrics. Inflation of the cuff by the minimum volume of air needed to reach the just sealing pressure is suggested to minimize the leakage volume.

Effect of different types of laryngeal mask airway placement on the right internal jugular vein: A prospective randomized controlled trial

BACKGROUND In recent years, with the popularity of laryngeal mask airway(LMA) for the management of clinical anesthesia, the influence of the LMA on the position and blood flow of the internal jugular vein(IJV) has attracted an increasing amount of attention.AIM To investigate the effect of placement of different types of LMA(Supreme LMA,Guardian LMA, I-gel LMA) on the position and blood flow of the right IJV.METHODS This was a prospective randomized controlled trial. A total of 102 patients aged 18-75 years who were scheduled to undergo laparoscopic abdominal surgery with general anesthesia were randomly assigned to three groups: Supreme LMA(group 1), Guardian LMA(group 2), and I-gel LMA(group 3) groups. The main indicator was the overlap index(OI) of IJV and the common carotid artery(CCA)at the high, middle, and low points before and after the placement of the LMA.The second indicators were the proportion of ultrasound-simulated needle crossing the IJV and CCA, and the cross-sectional area and blood flow velocity of the IJV before and after placement of the LMA at the middle point.RESULTS Data from 100 patients were included in the statistical analysis. The OI increased significantly after placement of the LMA in the three groups at the three points(P< 0.01), except group 2 at the low point. In group 2 and group 3, the OI was lower than that in group 1 after LMA insertion at the high point(P < 0.0167). At the middle point, after LMA insertion, the proportion of simulated needle crossing the IJV significantly decreased in all three groups(P < 0.05), and the proportion in group 2 was higher than that in group 3(P < 0.0167). The proportion of simulated needle crossing the CCA or both the IJV and CCA significantly increased in group 1 and group 2(P < 0.05), which increased with no statistical significance in group 3. After LMA insertion, the cross-sectional area of the IJV significantly increased, while the blood flow velocity significantly decreased(P <0.01). There was no significant difference among the three groups.CONCLUSION The placement of Supreme, Guardian, and I-gel LMA can increase the OI, reduce the success rate of IJV puncture, increase the incidence of arterial puncture, and cause congestion of IJV. Type of LMA did not influence the difficulty of IJV puncture. Therefore when LMA is used, ultrasound is recommended to guide the IJV puncture.

Clinical Observation of Double Tube Laryngeal Mask in Fast-Track Anesthesia for Limb Orthopedic Surgery in Children with Cerebral Palsy

Objective: To compare and analyze the effect and safety of double tube laryngeal mask and endotracheal intubation general anesthesia in fast track anesthesia for limb orthopaedic surgery in children with cerebral palsy. Methods: 78 children with cerebral palsy undergoing limb orthopedic surgery were randomly divided into laryngeal mask group and intubation group, with 39 cases in each group. The perioperative hemodynamic indexes, anesthesia effect related indexes, anesthesia related complications or adverse reaction rates of the two groups were observed and compared between the two groups. Results: When the two groups of children entered the room, there was no significant difference in MAP and HR (P > 0.05);MAP and HR of children in the intubation group were higher than those in the laryngeal mask anesthesia group (P Conclusion: Laryngeal mask is used to establish the airway of intravenous general anesthesia in limb orthopaedic surgery of children with cerebral palsy, which is conducive to the stability of children’s circulatory and respiratory system, to reduce the impact of narcotic drugs on children, to reduce the incidence of postoperative anesthesia related complications, and to improve the anesthetic effect. It meets the requirements of fast track anesthesia, and can be widely used in clinical practice.

Study on Effect of Laryngeal Mask Anesthesia and Endotracheal Intubation Anesthesia on Elderly Patients Undergoing Laparoscopic Gallbladder Surgery

Objective:To analyze the effect of laryngeal mask anesthesia and endotracheal intubation anesthesia in elderly laparoscopic gallbladder surgery.Methods:100 subjects of the experiment came from elderly patients with gallbladder stones admitted from September 2016 to September 2019 in our hospital.There were group A and group B of 50 cases each,and were used tube anesthesia and laryngeal mask anesthesia,then comparing the anesthesia effect.Results:Statistical significance(P<0.05):Air pressure and end-respiratory carbon dioxide partial pressure index changes when immediately after insertion,immediately after removal,3 minutes after removal;heart rate,mean arterial pressure,airway pressure,and end-expiratory carbon dioxide index changes when 3 minutes after insertion and immediately before removal;blood glucose and cortisol changes when after insertion,immediately before removal and min after removal.No statistical significance(P>0.05):Changes in heart rate,mean arterial pressure,airway pressure,and endexpiratory carbon dioxide indexes before insertion;changes in blood glucose and cortisol indexes before insertion.Conclusion:It is more ideal for elderly patients with abdominal cavity and gallbladder surgery to have laryngeal mask anesthesia,which can effectively keep blood circulation stable and have promotion value.

Safety of removal of ProSeal laryngeal mask airway in children in the supine versus lateral position in a deep plane of anesthesia:A randomized controlled trial

Importance:When a ProSeal laryngeal mask airway(PLMA)is removed with the child in a deep plane of anesthesia,the upper airway muscle tone and protective upper airway reflexes may be obtunded.Objective:To determine whether the supine or lateral position is safer for the removal of a PLMA in deeply anesthetized children by comparing the incidence of upper airway complications.Methods:This randomized single-blind comparative trial was conducted at a tertiary care hospital between January 2020 and September 2020.Forty children of the American Society of Anesthesiologists class I/II of ages 1–12 years age undergoing surgery under general anesthesia with PLMA used as the definitive airway device were recruited.Patients were randomly allocated to lateral group or supine group for PLMA removal in a deep plane of anesthesia in the lateral or supine position.The primary outcome was the number of patients experiencing one or more upper airway complications and the secondary outcomes were incidence of individual respiratory adverse effects and of severe airway complications.Results:The incidence of airway complications was 30%in the supine group and 20%in the lateral group(P=0.6641).Incidence of laryngospasm,immediate stridor,and excessive secretions were similar.Early stridor and oxygen desaturation were higher in the supine group(P=0.0374,P=0.0183 respectively).Interpretation:The overall incidence of upper airway complications was similar with the removal of a PLMA in the supine or lateral position in deeply anesthetized children.The incidence of oxygen desaturation and stridor were higher with PLMA removal in the supine as compared to the lateral position.

Intraoperative awake anesthesia applied for tumor excision in cerebral functional areas

Objective:To observe the feasibility and safety of awake anesthesia for tumor excisions in pa- tients with brain tumors involving cerebral functional areas.Methods:Fifty patients with brain tumors in- volving cerebral functional areas,ASAⅠ-Ⅱgrade,were enrolled in this study.Propofol and remifentanil were used for total intravenous anesthesia,and a laryngeal mask airway(LMA)was inserted for the air- way opening and synchronized intermittent mandatory ventilation(SIMV).At the surgeon's request for an intraoperative wake-up test,the propofol infusion was stopped advance of 10-15 min,the remifentanil in- fusion rate was decreased to 0.050-0.075μg/kg from 0.10-0.20μg/kg per min for easing surgical pain. The LMA was removed until the patient awakened.The anesthesiologist then kept up an on-going neuro- logical examination.After that,anesthesia was re-deepened and LMA was re-inserted until the whole surgery was accomplished.Results:Forty-six of 50 patients(92%)were successfully awakened and 4 (8%)failed to complete the intraoperative wake-up test because of dyspnea,over-sedation,or severe hy pertension.No severe complications occurred during the whole process.Conclusions:During the awake anesthetic period,the intraoperative wake-up test combined with navigation,evoked potential and ultra- sound techniques can help surgeons excise maximumly and precisely the brain tumors near to or in the functional areas.

Investigating the Fluid Seal of Supraglottic Airway Devices in Humans Using Indicator Dye via the Drainage Tube:A Potential Roadmap for Future Studies

Background: The fluid seal of supraglottic airway devices (SGA) protects the airway from fluid contamination. We evaluated the suitability of indicator dye placement in the upper digestive tract of anesthetized patients combined with fiberoptical tracing to investigate the fluid seal of SGA. Methods: Patients swallowed a capsule of indigo carmine green (ICG) prior to induction of anaesthesia. After induction of anesthesia, one of two different SGA (either an i-GelTM or an LMA-SupremeTM (LMA-S)) was inserted after randomization. Methylene blue stained normal saline was injected through the proximal opening of drainage tube during mechanical ventilation as well as spontaneous breathing. We monitored regurgitation of ICG with a flexible fiberscope (FO) inserted through the drainage tube and checked for the appearance of methylene blue in the mask bowl with the FO inserted through the airway tube. Results: In thirty-six patients with an i-GelTM and 37 with a LMA-S no regurgitation of ICG was observed at the level of the upper oesophageal sphincter (UES). Methylene blue stained saline was not visible in any patient during pressure-controlled ventilation, but was detected in two of the 36 patients with the i-GelTM during spontaneous breathing. Conclusion: Instilling dye through the drainage tube of SGA models with a built-in drainage tube represents a useful method to examine and to compare the fluid seal of different SGA. Our protocol presented in this study proved to be an easy and reproducible approach for future studies. Furthermore, the clinical results gained during this evaluation highlight the necessity for further investigations regarding the fluid seal competencies of SGAs in humans under clinical conditions.

Laryngeal Mask Airway for Cesarean Delivery： A 5-Year Retrospective Cohort Study

Background： The laryngeal mask airway （LMA） is the most commonly used rescue airway in obstetric anesthesia. The aim of this retrospective cohort study was to evaluate the application of the LMA in parturients undergoing cesarean delivery （CD） for 5 years in our hospital. As a secondary objective, we investigated the incidence of airway-related complication in obstetric general anesthesia （GA）. Methods： We collected electronic data for all obstetric patients who received GA for CD between January 2010 and December 2014 in Peking University First Hospital. Based on the different types of airway device, patients were divided into endotracheal intubation （ET） group and LMA group. The incidences of regurgitation and aspiration, as well as maternal and neonatal postoperative outcomes were compared between groups. Results： During the 5-year study, GA was performed in 192 cases, which accounted for 2.0% of all CDs. The main indications fbr GA were contraindication to neuraxial anesthesia or a failed block. Among these, ET tube was used in 124 cases （68.9%） and LMA in 56 cases （31.1%）. The percentage of critical patients above the American Society of Anesthesiologists＇ Grade II was 24/124 in ET group and 4/56 in LMA group （P = 0.036）. The emergent delivery rate was 63.7% for ET group and 37.5% for LMA group （P = 0.001）. None of the patients had regurgitation or aspiration. There were no significant differences in terms of neonatal Apgar scores, maternal and neonatal postoperative outcomes between the two groups. Conclusions： Our results suggested that GA was mainly used for contraindication to neuraxial anesthesia or a failed block, and emergent CDs accounted for most cases. The second-generation LMA could be used for obstetric anesthesia, but correct position to achieve a good seal is the key to prevent reflux and aspiration. Whether they could replace the tracheal tube in routine practice needs further large prospective studies.

Comparative study of hemodynamic responses to orotra- cheal intubation with intubating laryngeal mask airway and direct laryngoscope

Background Intubating laryngeal mask airway （ILMA） offers a new approach for orotracheal intubation and is expected to produce less cardiovascular stress responses. However, the available studies provide inconsistent results. The purpose of this study was to identify whether there is a clinically relevant difference in hemodynamic responses to orotracheal intubation by using ILMA and direct laryngoscope （DLS）. Methods A total of 53 adult patients, ASA physical status I-II, scheduled for elective plastic surgery under general anesthesia requiring the orotracheal intubation, were randomly allocated to either DLS or ILMA groups. After a standard intravenous anesthesia induction, orotracheal intubation was performed. Noninvasive blood pressure and heart rate were recorded before （baseline values） and after anesthesia induction （post-induction values）, at intubation and every minute for the first 5 minutes after intubation. The data were analyzed using Chisquare test, paired and unpaired Student＇s t test, and repeated-measures analysis of variance as appropriate. Results The mean intubation time in the ILMA group was longer than that in the DLS group （P〈0.05）. The blood pressure and heart rate increased significantly after intubation in the two groups compared to the postinduction values （P〈0.05）, but the maximum value of blood pressure during the observation did not exceed the baseline value, while the maximum value of heart rate was higher than the baseline （P〈0.05）. During the observation, there were no significant differences in blood pressure and heart rate among each time point and in the maximum values between the two groups. Conclusions Orotracheal intubations by using ILMA and DLS produce similar hemodynamic response. ILMA has no advantage in attenuating the hemodynamic responses to orotracheal intubation compared with DLS.

Application of Minimum Effective Cuff Inflating Volume for Laryngeal Mask Airway and its Impact on Postoperative Pharyngeal Complications

Background：High intracuffpressure can cause severe pharyngeal complications including sore throat or hoarseness after laryngeal mask airway （LMA） removal postoperatively.Though the application of minimum effective cuffinflating volume is suggested to maintain airway sealing and adequacy of ventilation for patients receiving general anesthesia with LMA at lower level of the intracuffpressure,it is currently not a standard care in most of the anesthetic departments.In this study,the minimum effective cuff inflating volume was determined for classic LMA Well LeadTM （Well Lead Medical Co.,Ltd.,China） and its impact on postoperative pharyngeal complications was also explored.Methods：Patients with American Society of Anesthesiologists physical status （Ⅰ-Ⅲ） undergoing the short-duration urological surgery were recruited in this trial.First,the minimum effective cuff inflating volume was determined for size 4 or 5 LMA Well LeadTM in the study 1.Immediately following placement and confirmation of ideal LMA position,the cuff was inflated with 5,7,10 ml of air and up to 30 ml at 5 ml increment.The intracuff pressure,oropharyngeal leak pressure （OLP）,and inspiratory peak airway pressure under positive pressure ventilation at the corresponding cuff volume as indicated above were recorded.Second,the enrolled patients were randomly allocated into minimum effective cuff inflating volume group （MC） and routine care （RC） group in the study 2.The minimum effective cuff inflating volume was applied and maintained in MC group,whereas the cuff volume was inflated with half of the maximum cuff inflating volume recommended by manufacturer in RC group throughout the surgical procedure and stay in postanesthesia care unit prior to LMA removal.The incidence of pharyngeal complications at 0,2,24,and 48 h after removal of LMA and other intra-operative adverse events were also documented.Results：The intracuffpressure varied with the cuff inflating volume in a positive linear correlation manner （Y =11.68X-42.l,r2 =0.9191） under the range of 5-30 ml for size 4 LMA.In similar with size 4 LMA,the data were also showed the linear relationship between the intracuff pressure and the cuff inflating volume （Y =7.39X-10.9,r2 =0.8855） for size 5 LMA.The minimal effective cuff inflating volume for size 4 or 5 LMA was 7-9 ml in combination of considering OLP needed to maintain airway sealing during intermittently positive pressure ventilation.The intracuffpressure in MC group was lower compared with RC group （63.0 ± 3.7 vs.126.4 ± 24.0 cmH2O for size 4 LMA;55.6 ± 2.4 vs.138.5± 26.8 cmH2O for size 5 LMA;P ＜ 0.0001）.The incidence of pharyngeal adverse events was lower in MC group versus the RC group at 2,24 h after LMA removal.Conclusions：The relationship between the cuff inflating volume and the intracuffpressure for size 4 or 5 LMA Well LeadTM is in a linear correlation manner at the range of 5-30 ml.The minimal cuffinflating volume is adequate for satisfactory airway sealing and consequently associated with lower incidence of postoperative pharyngeal complications for LMA Well Lead.TM