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

PURPOSE

Remimazolam 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.

METHODS

This 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.

RESULTS

The 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.

CONCLUSION

Based 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 REGISTRATION

ClinicalTrials.gov ( NCT05298228 ); first submitted 6 March 2022.

Comparison of Laryngeal Mask Airway Seal Between Anesthesiologists and Individuals Without Previous Airway Experience

BACKGROUND

Tracheal intubation is the gold standard for airway management in emergency medicine, but more difficult to apply for inexperienced individuals than laryngeal mask airway (LMA).

OBJECTIVE

The aim of our study was to investigate if inexperienced individuals are able to secure the airway with the help of LMA after a short introduction. A second aim was to evaluate Thiel-fixed specimens against unfixed ones.

METHODS

In a body donor model, LMA application was evaluated between medical students without previous airway experience and anesthesiologists by comparing the sealing of the larynx using a water column applied to the esophagus.

RESULTS

LMAs were successfully applied in 46 out of 55 (83.6%) attempts by medical students and in 30 out of 39 (76.9%) attempts by anesthesiologists. Among medical students, 14.1% of all LMA applications were primarily leaky, compared with 18.8% in anesthesiologists. Esophageal sealing was better in Thiel-fixed specimens (leakage 10.9%) compared with unfixed specimens (leakage 22.9%). Our data showed no significant difference between anesthesiologists and medical students in terms of sealing of LMA. Therefore, we conclude that medical students without previous airway experience can quickly learn to apply LMA sufficiently and thus, achieve aspiration protection similar to anesthesiologists.

CONCLUSION

Medical students without previous airway experience can successfully insert LMAs after a short introduction. Thiel-fixed specimens are suitable for studies as well as for training in LMA application.

Comparing leak pressure of LMA® ProSeal™ versus i-gel® at head rotation: a randomized controlled trial

PURPOSE

The effect of head rotation on supraglottic airway (SGA) oropharyngeal leak pressure (OPLP) has not been well elucidated. The aim of this study was to help clarify which SGA device provides higher OPLP at head-rotated position.

METHODS

Patients who underwent elective surgery under general anesthesia were enrolled and randomly divided into laryngeal mask airway (LMA®) ProSeal™ and i-gel® groups. The allocated SGA device was inserted under anesthesia. The primary outcome was OPLP, and secondary outcomes were ventilation score, expiratory tidal volume, and maximum pressure under volume-controlled ventilation (VCV) with an inspiratory tidal volume of 10 mL·kg-1 ideal body weight and fibreoptic view of the vocal cords at 0°, 30°, and 60° head rotation.

RESULTS

Data from 78 and 76 patients were analyzed in the LMA ProSeal and i-gel groups, respectively. The mean (standard deviation) OPLP of the LMA ProSeal was significantly higher than that of the i-gel at the 60° head-rotated position (LMA ProSeal, 20.4 [6.5] vs i-gel, 16.9 [7.8] cm H2O; difference in means, 3.6; adjusted 95% confidence interval, 0.5 to 6.6; adjusted P = 0.02, adjusted for six comparisons). The maximum pressure under VCV at 60° head rotation was significantly higher in the LMA ProSeal group than in the i-gel group. The expiratory tidal volume of the LMA ProSeal did not significantly change with head rotation and was significantly higher than that of the i-gel at 60° head rotation. Ventilation score, fibreoptic view of the vocal cords, and complications were not significantly different between the ProSeal and i-gel groups.

CONCLUSIONS

The LMA ProSeal provides higher OPLP than the i-gel at a 60° head-rotated position under general anesthesia.

TRIAL REGISTRATION

Japan Registry of Clinical Trials (https://jrct.niph.go.jp) (JRCT1012210043); registered 18 October 2021.

Anesthetic Management of a Broken Tracheostomy Tube Stem as a Foreign Body in the Trachea: A Case Report

Tracheostomy is commonly performed in patients to secure the airway. There are known early and late complications related to tracheostomy. Few case reports have described the rupture of the stem of the tracheostomy tube and its migration into the tracheobronchial tree. Here we describe a pediatric case with a broken stem of the tracheostomy tube in the trachea, acting as a foreign body and causing mild respiratory distress. The patient was successfully managed with neck exploration under general anesthesia using a supraglottic airway device in low-resource settings. In addition, we have described the potential problems that may be faced while managing the airway of such patients and how to deal with these complications.

Comparative study of ventilation techniques with supraglottic airway devices in cats: volume-controlled vs pressure-controlled techniques

OBJECTIVES

This study compared the effectiveness of a new supraglottic airway device (SGAD) in cats undergoing anaesthesia using two types of mechanical ventilation: volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV).

METHODS

A total of 13 healthy cats (five male, eight female; median age 2 years [range 1-3]) were randomly allocated to either VCV or PCV. Five tidal volumes (6, 8, 10, 12 and 14 ml/kg) and five peak inspiratory pressures (4, 5, 6, 7 and 8 cmH2O) were randomly applied with a minute ventilation of 100 ml/kg/min. Various parameters, such as blood pressure, gas leakage, end-tidal CO2 (ETCO2) and work of breathing (WOB), were measured while using VCV or PCV.

RESULTS

The occurrence of hypotension (mean arterial blood pressure <60 mmHg) was slightly less frequent with VCV (38 events, 65 ventilating sessions) than with PCV (40 events, 65 ventilating sessions), but this difference did not reach statistical significance (P = 0.429). The number of leakages did not differ between the VCV group (3 events, 65 ventilating sessions) and the PCV group (3 events, 65 ventilating sessions) (P = 1.000). Hypercapnia was identified when using VCV (10 events, 65 ventilating sessions) less frequently than when using PCV (17 events, 65 ventilating sessions), but this difference did not reach statistical significance (P = 0.194). The study found a significantly higher WOB in the PCV group compared with the VCV group (P <0.034).

CONCLUSIONS AND RELEVANCE

The present results suggested that both VCV and PCV can be used with an SGAD during anaesthesia, with VCV preferred for prolonged mechanical ventilation due to its lower workload. Adjusting tidal volume or inspiratory pressure corrects hypercapnia.

The effect of class 3 obesity on the functionality of supraglottic airway devices: a historical cohort analysis with propensity score matching

PURPOSE

Supraglottic airway devices (SGAs) have been increasingly used as a primary airway in patients undergoing anesthesia as an alternative to endotracheal tubes. Second-generation devices have expanded their applicability to include uses in patients with obesity. Nevertheless, there is limited evidence of SGA suitability for patients with class 3 obesity (body mass index [BMI] ≥ 40 kg·m-2). As such, we compared rates of SGA functionality between patients with class 3 obesity and patients without class 3 obesity undergoing general anesthesia.

METHODS

We performed a propensity score matching analysis using inverse probability of treatment weighting to compare the functionality of SGAs in adult patients with class 3 obesity vs without class 3 obesity. These patients underwent surgery at a hospital in Queensland, Australia from November 2017 to September 2020 and had a SGA inserted as part of their anesthetic care. All data were collected from patients' electronic medical records. We included 321 patients in the cohort with class 3 obesity and 471 in the cohort without class 3 obesity (control/comparison). The estimated effect of class 3 obesity on SGAs was calculated using adjusted odds ratios (AORs) with their 95% confidence intervals (CIs).

RESULTS

The overall weighted prevalence of nonfunctional SGAs was 3.2%, with a significantly higher rate in the class 3 obesity cohort compared with the control cohort (4.7% vs 2.1%) (P = 0.04). This adjusted analysis illustrates that class 3 obesity was associated with an almost four times higher odds of a nonfunctional SGA (odds ratio [OR], 2.3; 95% CI, 1.0 to 5.1; AOR, 3.9; 95% CI, 1.4 to 10.6) than patients without class 3 obesity.

CONCLUSION

Patients with class 3 obesity (BMI ≥ 40 kg·m-2) had greater than three-fold odds of nonfunctional intraoperative SGAs than patients without class 3 obesity.

Airway Management During Diagnostic Laparoscopic Surgery: A Comparison of I-Gel and Proseal Laryngeal Mask Airway

Background

Supraglottic airway devices (SADs) may be used during laparoscopic procedures in place of the often utilised endotracheal tube. The Proseal laryngeal mask airway (PLMA) is designed with an inflatable cuff, which provides an excellent oropharyngeal seal, and the I-gel is a newer SAD designed with a softer and noninflatable cuff and sharing similar features with PLMA.

Aim and Objectives

This study compared the ease of insertion, haemodynamic and ventilatory parameters as well as morbidities associated with these SADs when used for airway management during diagnostic laparoscopic procedures.

Patients and Methods

Eighty American Society of Anaesthesiologist I and II patients aged 18-60 years undergoing diagnostic laparoscopic surgery under controlled ventilation had either I-gel or PLMA used for airway management. Anaesthesia was induced with standard dose of propofol, patient received atracurium, fentanyl and the SAD inserted. Pulse oximetry, capnography, noninvasive blood pressure, oropharyngeal leak pressure (OLP), and evidence of pharyngolaryngeal morbidity were assessed. Data were analysed using the Statistical Package for Social Sciences version 21.0. The quantitative variables were analysed using the Student's t test and the qualitative using the Chi-square test. A P value of less than 0.05 was considered significant.

Results

The success rates at first insertion for I-gel and PLMA were 95% and 80%, respectively (P = 0.04). The mean changes in mean arterial pressure following insertion were 9.6 mmHg (±4.7) and 10.6 mmHg (±8) for I-gel and PLMA, respectively (P = 0.02). The OLP during insufflation was higher in the PLMA (35.8 cmH2O) than in the I-gel group (27.9 cmH2O) (P = 0.57). In the I-gel group, 12.5% of the patients had oropharyngeal morbidities compared with 37.5% in the PLMA group (P = 0.009).

Conclusion

Both I-gel and PLMA provide optimal ventilation during abdominal insufflation, with PLMA providing a better oropharyngeal seal, whereas I-gel has a better haemodynamic profile.

Transient Hypoglossal and Lingual Nerve Injury Following the Use of I-gel Supraglottic Airway: A Case Report

Injury to the hypoglossal and/or lingual nerve is a rare occurrence with the use of a laryngeal mask airway (LMA) or supraglottic airway (SGA) device. There has been one prior report of a lingual and hypoglossal nerve injury with the i-gel™ SGA. We are describing the second reported hypoglossal and lingual transient nerve injury in a male patient while using an i-gel™ SGA. Although excessive cuff pressure has been cited as a possible cause, the i-gel™ does not have a cuff. This report highlights that hypoglossal nerve injury can still occur, even with the use of a cuffless LMA such as the i-gel™ SGA.

Comparison of standard weight-based and thenar eminence dimension-based selection of I-gel in pediatric patients - A randomized controlled study

Background and Aim

Supraglottic airway devices are increasingly being used for airway management. I-gel is being widely used even for pediatric patients. Although the weight-based selection of the size of the device seems to be the standard technique, this method may not be possible in all patients. The aim of the study was to compare the standard weight-based method with the thenar eminence dimension-based method for I-gel selection.

Material and Methods

A prospective randomized study was conducted on 74 pediatric patients of either sex, aged between 6 months and 15 years, belonging to American Society of Anesthesiologists (ASA) physical status I, II, and III and who were posted for various surgical procedures under general anesthesia. The study population was divided into two groups of 37 patients each. I-gel was inserted based on weight in group A patients and based on thenar eminence size in group B patients. Parameters like first attempt success rate, ease of insertion, and complications were compared between the two groups using Student's t-test and Chi-square test.

Results

The demographic values between the groups were comparable. The first attempt success rate was 97.4% in group A and 91.7% in group B (P = 0.358). Insertion of I-gel was unsuccessful in two patients in group B. Two patients of group B had blood staining of the device. None of the patients had complications related to insertion.

Conclusion

The thenar eminence dimension can be used instead of weight while choosing the size of I-gel in pediatric patients. None of the patients had complications related to device insertion.

Anesthetic Management of Inguinal Hernia Surgery Using a Second-Generation Supraglottic Airway in a Patient With Trisomy 18: A Case Report

Children with trisomy 18 have abnormal airway anatomy, making their airway management challenging. Only a few papers have comprehensively described and discussed the use of supraglottic airway devices in patients with trisomy 18. We present a case of a 20-month-old boy with trisomy 18 who was scheduled for open repair of the right inguinal hernia. He had micrognathia, a short neck, and an atrial septal defect but was in a clinically stable condition. A supraglottic airway device was inserted under general anesthesia. The patient's respiration was maintained by pressure support ventilation with spontaneous breathing. A right ilioinguinal-iliohypogastric nerve block was performed for perioperative analgesia. The surgery ended without complications. After removing the supraglottic airway device and ensuring proper respiratory parameters, the patient was transferred to the post-anesthesia care unit. In our case, supraglottic airway devices could be effectively used as a primary airway for inguinal hernia repair. The concomitant ilioinguinal-iliohypogastric nerve block was helpful for anesthetic management with spontaneous breathing maintained using pressure support ventilation. A supraglottic airway device may be a potential alternative as a primary airway for superficial surgery in pediatric patients with trisomy 18. For pediatric patients with difficult airways, a second-generation supraglottic airway device with the insertion of a gastric tube to prevent gastric insufflation combining pressure support ventilation and positive end-expiratory pressure may be a beneficial choice for the maintenance of spontaneous breathing.

Comparison of Clinical Performance of C-MAC Video Laryngoscope Guided vs Blind Placement of I-Gel® in Paediatric Patients: A Randomized Controlled Open-Label Trial

Objective

Placement of the supraglottic airway devices under direct vision has been shown to decrease the incidence of malposition in adults. This study was designed to compare the clinical performance of C-MAC guided and blind placement of i-gel® in paediatric patients.

Methods

The present prospective, randomized controlled study was conducted on 102 paediatric patients scheduled to undergo elective infraumbilical surgeries under general anaesthesia. Patients were randomly divided into group "B" (blind) and group "C" (C-MAC) based on the technique used for placement of i-gel®. The primary objective of the study was to compare the incidence of malposition based on the fiberoptic bronchoscope (FOB) score of the glottic view. Oropharyngeal leak pressure (OPLP), hemodynamic parameters, and insertion characteristics (time taken to insert and the number of attempts) were secondary objectives. Categorical data were presented as ratio or percentage and continuous data were presented as mean ± standard deviation or median [95% confidence interval (CI)].

Results

The incidence of malposition (Brimacombe score 1 or 2) was significantly lower in group C compared to group B (7.8% vs 49% respectively) (P < 0.001); implying a relative risk reduction of 2.42 (95% CI 1.72 to 3.40) with C-MAC. On FOB assessment, the median (interquartile range) Brimacombe score was significantly better in group C [4 (4-4)] compared to group B [3 (2-3)] (P < 0.001). The OPLP was significantly higher in group C compared to group B. Other insertion characteristics were comparable in both the study groups.

Conclusion

Compared to blind placement, C-MAC guided placement ensures proper alignment of i-gel® with periglottic structures and proper functioning of i-gel®.

Postoperative pulmonary complications in older patients undergoing elective surgery with a supraglottic airway device or tracheal intubation

The two most commonly used airway management techniques during general anaesthesia are supraglottic airway devices and tracheal tubes. In older patients undergoing elective non-cardiothoracic surgery under general anaesthesia with positive pressure ventilation, we hypothesised that a composite measure of in-hospital postoperative pulmonary complications would be less frequent when a supraglottic airway device was used compared with a tracheal tube. We studied patients aged ≥ 70 years in 17 clinical centres. Patients were allocated randomly to airway management with a supraglottic airway device or a tracheal tube. Between August 2016 and April 2020, 2900 patients were studied, of whom 2751 were included in the primary analysis (1387 with supraglottic airway device and 1364 with a tracheal tube). Pre-operatively, 2431 (88.4%) patients were estimated to have a postoperative pulmonary complication risk index of 1-2. Postoperative pulmonary complications, mostly coughing, occurred in 270 of 1387 patients (19.5%) allocated to a supraglottic airway device and 342 of 1364 patients (25.1%) assigned to a tracheal tube (absolute difference -5.6% (95%CI -8.7 to -2.5), risk ratio 0.78 (95%CI 0.67-0.89); p < 0.001). Among otherwise healthy older patients undergoing elective surgery under general anaesthesia with intra-operative positive pressure ventilation of their lungs, there were fewer postoperative pulmonary complications when the airway was managed with a supraglottic airway device compared with a tracheal tube.

Conventional versus reverse insertion of i-gel® in overweight and obese patients - Interventional randomised controlled trial

Background and Aims

The supraglottic airway device, i-gel, is used in obese patients for short- to medium-duration surgical procedures. Insertion techniques have contributed to the successful and proper placement of i-gel in the first attempt. This study aims to compare two techniques for successfully inserting i-gel in the first attempt in overweight and obese patients as measured by oropharyngeal leak pressure (OLP).

Methods

This interventional, randomised, controlled study was conducted after ethical approval, and trial registration in overweight and obese patients. Patients were randomised into two groups: In Group C, the conventional technique was used, while in Group R, the reverse technique was used to insert i-gel. OLP, successful placement, required manipulations, time taken for insertion, number of attempts, and intraoperative and postoperative complications were studied. The collected data were analysed statistically.

Results

The mean OLP (30.46 ± 3.76 vs. 32.12 ± 3.10 mmHg, P = 0.018) and the mean time of insertion (16.42 ± 1.86 vs. 13.98 ± 1.97 s, P = 0.001) for conventional and reverse techniques, respectively, were statistically significant and favourable for Group R compared to Group C. Successful placement of i-gel at the first attempt, ease of insertion, number of attempts and all the manipulations except withdrawal and advancement were comparable in both the groups. No postoperative complications were noted.

Conclusion

The reverse technique significantly favoured the actual OLP values and the mean insertion time. Successful placement of i-gel at the first attempt was observed with both conventional and reverse techniques.

Aerosol generation with the use of positive pressure ventilation via supraglottic airway devices: an observational study

The amount of aerosol generation associated with the use of positive pressure ventilation via a supraglottic airway device has not been quantified. We conducted a two-group, two-centre, prospective cohort study in which we recruited 21 low-risk adult patients scheduled for elective surgery under general anaesthesia with second-generation supraglottic airway devices. An optical particle sizer and an isokinetic sampling probe were used to record particle concentrations per second at different size distributions (0.3-10 μm) during use as well as baseline levels during two common activities (conversation and coughing). There was a median (IQR [range]) peak increase of 2.8 (1.5-4.5 [1-28.1]) and 4.1 (2.0-7.1 [1-18.2]) times background concentrations during SAD insertion and removal. Most of the particles generated during supraglottic airway insertion (85.0%) and removal (85.3%) were < 3 μm diameter. Median (IQR [range]) aerosol concentration generated by insertion (1.1 (0.6-5.1 [0.2-22.3]) particles.cm^-3 ) and removal (2.1 (0.5-3.0 [0.1-18.9]) particles.cm^-3 ) of SADs were significantly lower than those produced during continuous talking (44.5 (28.3-70.5 [2.0-134.5]) particles.cm^-3 ) and coughing (141.0 (98.3-202.8 [4.0-296.5]) particles.cm^-3 ) (p < 0.001). The aerosol levels produced were similar with the two devices. The proportion of easily inhaled and small particles (<1 μm) produced during insertion (57.5%) and removal (57.5%) was much lower than during talking (99.1%) and coughing (99.6%). These results suggest that the use of supraglottic airway devices in low-risk patients, even with positive pressure ventilation, generates fewer aerosols than speaking and coughing in awake patients.

Comparison between LMA ProSeal and I-gel airway in anesthetized patients on spontaneous ventilation during daycare procedures: A prospective randomized study

Background

General anesthesia remains the most popular technique for ambulatory surgeries with patients, surgeons, and anesthesia providers. The supraglottic airway (SGA) devices result in fewer incidences of sore throat, laryngospasm, coughing, and hoarseness as compared to inserting a tracheal tube. This study was conducted to compare two second-generation SGA devices, LMA ProSeal and I-gel airway, in anesthetized patients on spontaneous ventilation during daycare procedures to establish the superior SGA device.

Methodology

This prospective randomized study was done on 90 patients of either sex aged 15-60 years, ASA grade I-II, Mallampatti grade I and II, and BMI between 20 and 30 kg/m2 scheduled for elective surgeries of duration less than 90 min. Patients were randomly allocated into two groups-group A (I-gel) and group B (LMA ProSeal). Insertion parameters, hemodynamic responses, oxygenation, ventilation, peak airway pressure (PAP), and postoperative complications were recorded. Statistical analysis was done using SPSS version 21.0 statistical analysis software.

Results

Mean insertion time of LMA ProSeal was found to be significantly higher as compared to I-gel (33.27 ± 3.88 vs 18.49 ± 3.18 s; P < 0.001). No significant difference was found between the groups in the number of attempts and of operators attempted for insertion, as well as in hemodynamic response, oxygenation, and ventilation. Postoperative complications were lesser in group A.

Conclusion

I-gel is an easy-to-insert cuffless SGA device requiring lesser time for insertion, provides adequate ventilation with lesser postoperative complications and thus appears to be better than LMA ProSeal.

Evaluation of the New SingularityTM Air versus Ambu® Aura GainTM: A Randomized, Crossover Mannequin Study

Background: This randomised crossover mannequin study aimed to compare the insertion time for the newly developed SingularityTM Air and the Ambu® AuraGainTM. The SingularityTM Air includes a bendable tube in order to allow optimal passform. Methods: Fifty anaesthetists with a minimum of 100 supraglottic airway device insertions were recruited and randomly assigned to start either with the SingularityTM Air or with the Ambu® AuraGainTM. Participants watched a tutorial video the day before the assessment and received a standardized introduction immediately before the assessment. The primary outcome was the time for successful insertion. Secondary parameters were the overall insertion success rate, the numbers of insertion attempts (maximum three), the glottic view through a flexible bronchoscope, and the success rate for gastric tube insertion. Results: Fifty participants were eventually recruited and randomly assigned to insert both devices according to the randomization. The insertion time was 24 s for SingularityTM Air as compared to 20 s for Ambu® AuraGainTM (p < 0.001). Overall insertion rate was 92% for the SingularityTM Air as compared to 100% for the Ambu® AuraGainTM (p could not be derived as one variable is a constant). The primary insertion success rate was better for the Ambu® AuraGainTM than for the SingularityTM Air (94% versus 68%; p: 0.002, respectively). Conclusion: The time for successful insertion and the insertion success rate for the newly developed SingularityTM Air is inferior to that for the Ambu® AuraGainTM.

Radiologic Imaging of the In Vivo Position of the New Supraglottic Airway Device Spritztube(®) in an Adult Patient-A Case Report

Spritztube^® is a new supraglottic airway device that allows either extraglottic ventilation or orotracheal intubation with the same device. The aim of the present report is to provide the first radiologic images of the Spritztube in situ in a living human and to assess the depth of insertion and its anatomical relationships in vivo. We present the case of a 55-year-old man who was admitted to our centre to perform an interventional neuroradiological procedure. We obtained and analysed radiologic images of the head and neck of an adult patient to ascertain the position of the cuffs of the Spritztube relative to different anatomic structures. The insertion and depth of the device, correct tip positioning, effects of the distal and proximal cuffs on adjacent soft tissues, and the position of the pharyngeal cuff from the cranial to the hyoid bone were evaluated. Our report shows that Spritztube could be helpful in maintaining an adequate airway during radiologic procedures.

Supraglottic airway device to improve ventilation success and reduce pulmonary aspiration during cardio-pulmonary resuscitation by basic life support rescuers: a randomised cross-over human cadaver study

Objectives: Early airway management during cardiopulmonary resuscitation (CPR) prevents aspiration of gastric contents. Endotracheal intubation is the gold standard to protect airways, but supraglottic airway devices (SGA) may provide some protection with less training. Bag-mask ventilation (BMV) is the most common method used by rescuers. We hypothesized that SGA use by first rescuers during CPR could increase ventilation success rate and also decrease intragastric pressure and pulmonary aspiration.Methods: We performed a randomized cross-over experimental trial on human cadavers. Protocol A: we assessed the rate of successful ventilation (chest rise), intragastric pressure, and CPR key time metrics. Protocol B: cadaver stomachs were randomized to be filled with 300 mL of either blue or green serum saline solution through a Foley catheter. Each rescuer was randomly assigned to use SGA or BMV during a 5-minute standard CPR period. Then, in a crossover design, the stomach was filled with the second colour solution and another 5-minute CPR period was performed using the other airway method. Pulmonary aspiration, defined as the presence of coloured solution below the vocal cords, was assessed by a blinded operator using bronchoscopy. A generalized linear mixed model was used for statistical analysis.Results: Protocol A: Forty-eight rescuers performed CPR on 11 cadavers. Median ventilation success was higher with SGA than BMV: 75.0% (IQR: 59.8-87.3) vs. 34.7% (IQR: 25.0-50.0), (p = 0.003). Gastric pressure and differential (maximum minus minimum) gastric pressure were lower in the SGA group: 2.21 mmHg (IQR: 1.66; 2.68) vs. 3.02 mmHg (IQR: 2.02; 4.22) (p = 0.02) and 5.70 mmHg (IQR: 4.10; 7.60) vs. 8.05 mmHg (IQR: 5.40; 11.60) (p = 0.05). CPR key times were not different between groups. Protocol B: Ten cadavers were included with 20 CPR periods. Aspiration occurred in 2 (20%) SGA procedures and 5 (50%) BMV procedures (p = 0.44).Conclusion: Use of SGA by rescuers improved the ventilation success rate, decreased intragastric pressure, and did not affect key CPR metrics. SGA use by basic life support rescuers appears feasible and efficient.

Risk factors for postoperative sore throat associated with i-gel™, a supraglottic airway device

i-gel™ is a supraglottic airway device widely used for airway management during general anesthesia as an alternative to tracheal intubation. It sometimes results in a sore throat postoperatively; however, the risk factors for a postoperative sore throat caused by i-gel remain unclear. Here, we clarify the risk factors for a postoperative sore throat associated with i-gel insertion. We retrospectively reviewed the data of 426 adult patients who received general anesthesia with i-gel at our institution from January 2018 to December 2019. The incidence of postoperative sore throat and intraoperative data (size of i-gel, number of insertion attempts, total insertion time, and dose of the neuromuscular blocker and opioid) were evaluated. Logistic regression analysis was performed to identify the risk factors. Postoperative sore throat following i-gel insertion occurred in 24/426 patients (5.6%). The insertion time was significantly associated with the incidence of postoperative sore throat in the univariate analysis, but not in the multivariate analysis (P=0.519). Increased doses of neuromuscular blockers before i-gel insertion (odds ratio [OR], 5.46; 95% confidence interval [CI], 1.50-19.80; P=0.001) and reduced doses of intraoperative fentanyl (OR, 0.51; 95% CI, 0.28-0.93; P=0.028) were risk factors in the univariate and multivariate analyses. In the subgroup that used neuromuscular blockers before i-gel insertion, only an increased dose of neuromuscular blocker (OR, 17.2; 95%, CI 1.06-280; P=0.046) was an associated risk factor in the univariate and multivariate analyses. Overall, increased doses of neuromuscular blockers before i-gel insertion could contribute to the development of postoperative sore throat.

Prehospital Use of the Esophageal Tracheal Combitube Supraglottic Airway Device: A Retrospective Cohort Study

BACKGROUND

In the province of Quebec (Canada), paramedics use the esophageal tracheal Combitube (ETC) for prehospital airway management.

OBJECTIVES

Our main objective was to determine the proportion of patients with successful ventilation achieved after ETC use. Our secondary aim was to determine the number of ETC insertion attempts required to ventilate the patient.

METHOD

This is a retrospective cohort study. All patients who had ≥1 attempt to insert an ETC during prehospital care between January 1, 2017 and December 31, 2018 were included. Prehospital and in-hospital data were extracted. Successful ventilation was defined as thorax elevation, lung sounds on chest auscultation, or positive end-tidal capnography after ETC insertion.

RESULTS

A total of 580 emergency medical services interventions (99.3% cardiac arrests) were included. Most patients were men (62.5%) with a mean age 67.0 years (SD 17.6 years), and 35 (13.1%) of the 298 patients transported to emergency department survived to hospital discharge. Sufficient information to determine whether ventilation was successful or not was available for 515 interventions. Ventilation was achieved during 427 (82.7%) of these interventions. The number of ETC insertion attempts was available for 349 of the 427 successful ETC use. Overall, the first insertion resulted in successful ventilation during 294 interventions for an overall proportion of first-pass success ranging between 57.1% and 72.1%.

CONCLUSION

Proportions of successful ventilation and ETC first-pass success are lower than those reported in the literature with supraglottic airway devices. The reasons explaining these lower rates and their impact on patient-centered outcomes need to be studied.

A quantitative evaluation of aerosol generation during supraglottic airway insertion and removal

Many guidelines consider supraglottic airway use to be an aerosol-generating procedure. This status requires increased levels of personal protective equipment, fallow time between cases and results in reduced operating theatre efficiency. Aerosol generation has never been quantitated during supraglottic airway use. To address this evidence gap, we conducted real-time aerosol monitoring (0.3-10-µm diameter) in ultraclean operating theatres during supraglottic airway insertion and removal. This showed very low background particle concentrations (median (IQR [range]) 1.6 (0-3.1 [0-4.0]) particles.l-1 ) against which the patient's tidal breathing produced a higher concentration of aerosol (4.0 (1.3-11.0 [0-44]) particles.l-1 , p = 0.048). The average aerosol concentration detected during supraglottic airway insertion (1.3 (1.0-4.2 [0-6.2]) particles.l-1 , n = 11), and removal (2.1 (0-17.5 [0-26.2]) particles.l-1 , n = 12) was no different to tidal breathing (p = 0.31 and p = 0.84, respectively). Comparison of supraglottic airway insertion and removal with a volitional cough (104 (66-169 [33-326]), n = 27), demonstrated that supraglottic airway insertion/removal sequences produced <4% of the aerosol compared with a single cough (p < 0.001). A transient aerosol increase was recorded during one complicated supraglottic airway insertion (which initially failed to provide a patent airway). Detailed analysis of this event showed an atypical particle size distribution and we subsequently identified multiple sources of non-respiratory aerosols that may be produced during airway management and can be considered as artefacts. These findings demonstrate supraglottic airway insertion/removal generates no more bio-aerosol than breathing and far less than a cough. This should inform the design of infection prevention strategies for anaesthetists and operating theatre staff caring for patients managed with supraglottic airways.

Success of placement and complications during v-gel placement and maintenance of anaesthesia

Objectives

Airway management during anaesthesia in cats is always a demanding task and is associated with several complications. The aim of this study was to evaluate the practicability and complications during feline-specific laryngeal mask placement in anaesthetised cats as an alternative to endotracheal intubation.

Methods

In this prospective clinical study, laryngeal masks were placed in 148 anaesthetised cats. Success of placement was evaluated by capnography.

Results

Placement was possible at the first attempt in 136 cats, at the second attempt in eight cats and at the third attempt in one cat. In one cat, placement was not possible. Two cats were excluded. Failure to position the laryngeal mask at the first attempt was not different between laryngeal mask sizes (P = 0.313) or positioning during placement (P = 0.406). In nine cats, the laryngeal mask dislocated during the procedure. Dislocation occurred more often in the dorsal position than in the sternal (P = 0.018) and right lateral positions (P = 0.046). Mucous obstruction of the laryngeal mask occurred in one of these cats and regurgitation in another. Material-related issues, such as disconnection of the parts of the laryngeal mask and leakage of the balloon, were observed in 2/8 laryngeal masks.

Conclusions and relevance

The placement of a feline-specific laryngeal mask was easy to perform. In about 7% of the cases, replacement of the device was required due to mispositioning or dislocation. Full monitoring, including capnography, should be provided to uncover dislocation and airway obstruction immediately.

Temporomandibular joint dysfunction following the use of a supraglottic airway device during general anaesthesia: a prospective observational study

Supraglottic airway devices are commonly used to manage the airway during general anaesthesia. There are sporadic case reports of temporomandibular joint dysfunction and dislocation following supraglottic airway device use. We conducted a prospective observational study of adult patients undergoing elective surgery where a supraglottic airway device was used as the primary airway device. Pre-operatively, all participants were asked to complete a questionnaire involving 12 points adapted from the Temporomandibular Joint Scale and the Liverpool Oral Rehabilitation Questionnaire. Objective measurements included inter-incisor distance as well as forward and lateral jaw movements. The primary outcome was the inter-incisor distance, an accepted measure of temporomandibular joint mobility. Both the questionnaire and measurements were repeated in the postoperative period and we analysed data from 130 participants. Mean (SD) inter-incisor distance in the pre- and postoperative period was 46.5 (7.2) mm and 46.3 (7.5) mm, respectively (p = 0.521) with a difference (95%CI) of 0.2 (-0.5 to 0.9) mm. Mean (SD) forward jaw movement in the pre- and postoperative period was 3.6 (2.4) mm and 3.9 (2.4) mm, respectively (p = 0.018). Mean (SD) lateral jaw movement to the right in the pre- and postoperative period was 8.9 (4.1) mm and 9.1 (4.0) mm, respectively (p = 0.314). Mean (SD) lateral jaw movement to the left in the pre- and postoperative period was 8.8 (4.0) mm and 9.3 (3.6) mm, respectively (p = 0.008). The number of patients who reported jaw clicks or pops before opening their mouth as wide as possible was 28 (21.5%) vs. 12 (9.2%) in the pre- and postoperative period, respectively (p < 0.001) with a difference (95%CI) of 12.3% (6.7-17.9%). There was no significant difference in the responses to the other 11 questions or in the number of patients who reported pain in the temporomandibular joint area postoperatively. No clinically significant dysfunction of the temporomandibular joint following the use of supraglottic airway devices in the postoperative period was identified by either patient questionnaires or objective measurements.

Laryngeal mask airway protector generates higher oropharyngeal leak pressures compared to the laryngeal mask airway supreme: A randomized clinical trial in the ambulatory surgery unit

Background and Aims

The Laryngeal Mask Airway (LMA) Protector™ is one of the latest introduced supraglottic airway devices. It provides access and functional separation of the respiratory and digestive tracts. Compared to the LMA Supreme™, it has two digestive ports, one to provide suction in the pharyngeal region and one for gastric tube insertion. High oropharyngeal leak pressure is a marker for safe ventilation when using LMA devices. We hypothesized that oropharyngeal leak pressure of the LMA Protector™ is 5 cm H₂O higher than the oropharyngeal leak pressure of the LMA Supreme™ at various cuff volumes. Secondary outcome measures were ease of insertion of both masks, fiberoptic confirmation of correct positioning, failures of insertion, presence of blood staining, sore throat, presence of air leak and insertion time.

Material and Methods

American Society of Anesthesiologists (ASA) I-III patients aged >18 years, scheduled for elective minor ambulatory surgery under general anesthesia with a LMA were included. Patients were randomized in the LMA Protector™ or LMA Supreme™ group based on a computer-generated random sequence table. After general anesthesia induction, oropharyngeal leak pressures were measured.

Results

Oropharyngeal leak pressures were significantly higher (P < 0.0001) for LMA Protector™ compared to LMA Supreme™ at different cuff volumes and a cuff pressure of 65 cm H₂O. Insertion time was significantly higher for the LMA Protector™ (29 sec) [interquartile range (IQR) 23, 35] compared to the LMA Supreme™ (19 sec) (IQR 16, 22) (P < 0.0001). There were no statistically significant differences in ease of insertion (number of attempts for succesful positioning), failures of insertion, presence of blood staining, sore throat or presence of air leak.

Conclusion

Oropharyngeal leak pressures were consistently higher (>5 cm H₂O) for LMA Protector™ compared to LMA Supreme™. LMA Protector™, therefore, allows effective ventilation at higher airway pressures than LMA Supreme™.

Trial Registration

http://clinicaltrials.gov.NCT03462550.

LMA® Gastro™: A paediatric experience

The laryngeal mask airway, the LMA® Gastro™ (Teleflex Medical, Athlone, Ireland), is a novel airway device which permits upper gastrointestinal (GI) endoscopy to be performed via a dedicated large calibre oesophageal lumen. It has been validated in adult studies, but to our knowledge, there have been no data published regarding its use in a paediatric population. Following a brief education programme, the LMA Gastro was introduced on a trial basis at our institution and made freely available. Over a four-month period, our pre-existing endoscopy audit framework captured data on a total of 55 patients who had the LMA Gastro device chosen as the primary airway for elective upper GI endoscopy. These data were collected prospectively by the treating anaesthetist and included a range of airway and endoscopy outcomes. Of the 55 patients, the LMA Gastro provided an adequate airway in 52 (94.5%). Forty-six (88.5%) were sited on first attempt, and 50 (96.2%) insertions were rated 'easy' by the anaesthetist. Aside from three insertion failures, there were no airway events. The endoscopy success rate was 100% in the 52 patients who had an LMA Gastro airway successfully inserted. First-pass oesophageal access was achieved in 51 (98%) cases, and 100% of insertions were rated 'easy' by the gastroenterologist. Despite our relative inexperience with it, the device had a high success rate for airway maintenance and oesophageal access in our paediatric patient population. In our institution, the LMA Gastro provided a useful airway option in older children undergoing elective upper GI endoscopy.

Effect on Chest Compression Fraction of Continuous Manual Compressions with Asynchronous Ventilations Using an i-gel® versus 30:2 Approach during Simulated Out-of-Hospital Cardiac Arrest: Protocol for a Manikin Multicenter Randomized Controlled Trial

The optimal airway management strategy during cardiopulmonary resuscitation is uncertain. In the case of out-of-hospital cardiac arrest, a high chest compression fraction is paramount to obtain the return of spontaneous circulation and improve survival and neurological outcomes. To improve this fraction, providing continuous chest compressions should be more effective than using the conventional 30:2 ratio. Airway management should, however, be adapted, since face-mask ventilation can hardly be carried out while continuous compressions are administered. The early insertion of a supraglottic device could therefore improve the chest compression fraction by allowing ventilation while maintaining compressions. This is a protocol for a multicenter, parallel, randomized simulation study. Depending on randomization, each team made up of paramedics and emergency medical technicians will manage the 10-min scenario according either to the standard approach (30 compressions with two face-mask ventilations) or to the experimental approach (continuous manual compressions with early insertion of an i-gel® supraglottic device to deliver asynchronous ventilations). The primary outcome will be the chest compression fraction during the first two minutes of cardiopulmonary resuscitation. Secondary outcomes will be chest compression fraction (per cycle and overall), compressions and ventilations quality, time to first shock and to first ventilation, user satisfaction, and providers' self-assessed cognitive load.

Evaluation of supraglottic airway device use during inhalation anesthesia in healthy African pygmy hedgehogs (Atelerix albiventris)

OBJECTIVE

To evaluate a supraglottic airway device (SGAD) designed for rabbits in African pygmy hedgehogs (Atelerix albiventris) during inhalation anesthesia.

STUDY DESIGN

Prospective, randomized, blinded experimental study.

ANIMALS

A total of 12 adult African pygmy hedgehogs (seven male, five female).

METHODS

Hedgehogs were placed in a chamber and anesthesia was induced using isoflurane in oxygen. Oropharyngeal endoscopy was performed and video recorded. The SGAD (v-gel R1) was inserted and connected to a Mapleson D circuit. Capnography, pulse oximetry and physiologic variables were measured during anesthesia, and lung inflation was tested at 10 and 20 cmH₂O. With the SGAD temporarily disconnected, anesthetized hedgehogs were randomly positioned into right and left lateral, dorsal and sternal recumbency to evaluate the effect of a change in body position on SGAD placement. Oropharyngeal endoscopy was repeated at the end of anesthesia, and recovery time was recorded. Pre- and post-SGAD placement endoscopy videos were retrospectively reviewed and scored for gross trauma.

RESULTS

The median [interquartile range (IQR)] time to successful SGAD placement was 38 (16-68) seconds. The time to SGAD placement decreased as the study progressed. SGAD required repositioning in six hedgehogs, median 2.5 (IQR, 1-3.5) adjustments each, to successfully perform lung inflation or maintain capnography readings. Lung inflation at 10 cmH₂O was successfully performed without leakage in nine animals, and in the other three animals after adjusting the SGAD at 1-2 time points. Inflation at 20 cmH₂O was rarely achieved without an air leak. Changes in heart and respiratory rates during anesthesia were not clinically relevant. Median endoscopic scores were 0 (no lesions) for both pre-and postplacement.

CONCLUSIONS AND CLINICAL RELEVANCE

The SGAD was relatively quickly and easily placed, permitted lung inflation and caused no significant oropharyngeal damage. The SGAD is a practical option for airway management in African pygmy hedgehogs.

Successful endotracheal intubation using i-gel supraglottic airway device and ultrasonography in a patient with bedside cervical traction: A case report

We report a case of successful endotracheal intubation using i-gel and ultrasonography without a laryngoscope in a patient with a bedside cervical traction device. A 57-year-old man was referred to the emergency department because of quadriparesis following a motor vehicle accident, who was confirmed to have cervical dislocation with spinal cord compression. For ventilation support, the i-gel rescue airway device was placed to secure the patient airway temporarily. Then, an endotracheal tube was passed through the stem of the i-gel while observing the optimal tube position with ultrasonography. This case showed that ultrasonography can be used for early confirmation of endotracheal tube placement into the trachea via the i-gel.

Dimensional compatibility and limitations of tracheal intubation through supraglottic airway devices: a mannequin-based in vitro study

BACKGROUND

Flexible bronchoscope-guided tracheal intubation through supraglottic airway devices (SGAs) is a well-established element of difficult intubation algorithms. Success can be limited by dimensional incompatibilities between tracheal tubes (TTs) and SGAs.

METHODS

In this in vitro study, we tested the feasibility of TT passage through SGAs, removal of SGAs over TTs, and the ability to guide the flexible bronchoscope with 13 TT brands (internal diameter, 6.5-8.0 mm) and ten different SGAs (#4 and #5) in an intubation mannequin.

RESULTS

We tested 1,040 combinations of SGAs and TTs. Tracheal tube passage failed in 155 (30%) combinations of the five tested first-generation SGAs (117 [46%] with SGA #4, 38 [15%] with SGA #5) and in three (0.6%) combinations of the five tested second-generation SGAs (two [0.8%] with SGA #4 and one [0.4%] with SGA #5). The reason for failed passage of a TT through a first-generation SGA consistently was a too-narrow SGA connector. Removal of the SGA over the TT in the 882 remaining combinations was impossible for all sizes of reinforced TTs, except the Parker Reinforced TT, and was possible for all non-reinforced TTs. Only one combination with SGA #4 and 84 combinations with SGA #5 were not ideal to adequately guide the flexible bronchoscope.

CONCLUSION

Clinically relevant combinations of adult-size TTs and SGAs can be incompatible, rendering flexible bronchoscope-guided tracheal intubation through an SGA impossible. Additional limitations exist regarding removal of the SGA and maneuverability of the flexible bronchoscope.

Difficult Airway Management in Neonates and Infants: Knowledge of Devices and a Device-Oriented Strategy

Difficult airway management (DAM) in neonates and infants requires anesthesiologists and critical care clinicians to respond rapidly with appropriate evaluation of specific situations. Therefore, organizing information regarding DAM devices and device-oriented guidance for neonate and infant DAM treatment will help practitioners select the safest and most effective strategy. Based on DAM device information and reported literature, there are three modern options for DAM in neonates and infants that can be selected according to the anatomical difficulty and device-oriented strategy: (1) video laryngoscope (VLS), (2) supraglottic airway device (SAD), and (3) flexible fiberoptic scope (FOS). Some VLSs are equipped with small blades for infants. Advanced SADs have small sizes for infants, and some effectively function as conduits for endotracheal intubation. The smallest FOS has an outer diameter of 2.2 mm and enables intubation with endotracheal tubes with an inner diameter of 3.0 mm. DAM in neonates and infants can be improved by effectively selecting the appropriate device combination and ensuring that available providers have the necessary skills.

Supraglottic airway device versus tracheal intubation and the risk of emergent postoperative intubation after general anaesthesia in adults: a retrospective cohort study

BACKGROUND

We examined the association between emergent postoperative tracheal intubation and the use of supraglottic airway devices (SGAs) vs tracheal tubes.

METHODS

We included data from adult noncardiac surgical cases under general anaesthesia between 2008 and 2018. We only included cases (n=59 991) in which both airways were deemed to be feasible options. Multivariable logistic regression, instrumental variable analysis, propensity matching, and mediation analysis were used.

RESULTS

Use of a tracheal tube was associated with a higher risk of emergent postoperative intubation (adjusted absolute risk difference [ARD]=0.80%; 95% confidence interval (CI), 0.64-0.97; P<0.001), and a higher risk of post-extubation hypoxaemia (ARD=3.9%; 95% CI, 3.4-4.4; P<0.001). The effect was modified by the use of non-depolarising neuromuscular blocking agents (NMBAs); mediation analyses revealed that 28.9% (95% CI, 14.4-43.4%; P<0.001) of the main effect was attributable to NMBA. Airway management modified the association of NMBA and risk of emergent postoperative intubation (P_interaction=0.02). Patients managed with an SGA had higher odds of NMBA-associated reintubation compared to patients managed with a tracheal tube (adjusted odds ratio [aOR]=3.65, 95% CI, 1.99-6.67 vs aOR=1.68, 95% CI, 1.29-2.18 [P<0.001], respectively).

CONCLUSIONS

In patients undergoing procedures under general anaesthesia that could be managed with either SGA or tracheal tube, use of an SGA was associated with lower risk of emergent postoperative intubation. The effect can partly be explained by use of NMBAs. Use of NMBAs in patients with an SGA appears to increase the risk of emergent postoperative intubation.

Blind intubation through an i-gel® in the prone position: A prospective cohort study

Accidental extubation in the prone position is a medical emergency in which quick and low resource demanding airway management is required. Regaining oxygenation is the primary goal, but sometimes intubation may be required to regain oxygenation. Blind intubation through an i-gel® (Intersurgical Ltd, Wokingham, Berkshire, UK) may be a quick and low resource demanding method. However, the success rate of the use of an i-gel as an intubation conduit in the prone position is unknown. This was a prospective study in patients scheduled for lumbar surgery. General anaesthesia was induced in the prone position and an i-gel was inserted. After successful ventilation, up to three attempts at intubation using a VivaSight-SL single-lumen tube (Ambu A/S, Ballerup, Denmark) were performed. The first attempt was blinded for the operator and the patient's head was in a neutral position. The second attempt was blinded for the operator with the patient's head rotated laterally. The third attempt was on-screen and allowed various manoeuvres to facilitate intubation. A success rate of 70% was deemed clinically acceptable. The study was terminated early after 14 subjects because the success rate of 70% was not achievable. However, ventilation using the i-gel in the prone position was successful in 13 patients (93%). Intubation was successful in only one patient at the first attempt, one patient at the second attempt and three patients at the third attempt. Overall, the success rate was 36%. Blind intubation using an i-gel as an intubation conduit in the prone position is not recommended.Netherlands Trial Register number NL6387 (NTR7659).

Comparison of endoscopic endotracheal intubation and the v-gel supraglottic airway device for spontaneously ventilating New Zealand white rabbits undergoing ovariohysterectomy

BACKGROUND

Due to the technical difficulties with endotracheal intubation of rabbits, a prospective, randomised, controlled study was performed to compare a rabbit-specific supraglottic airway device (SGAD), the v-gel, with endoscopic endotracheal intubation (EEI) in spontaneously breathing rabbits undergoing ovariohysterectomy.

METHODS

Fourteen adult female New Zealand white rabbits were randomly allocated to one of two groups based on the method of airway establishment: EEI or v-gel SGAD. Anaesthesia was induced with ketamine and xylazine and maintained using isoflurane in 100 per cent oxygen. Comparisons were made between groups based on placement time of endotracheal tube/SGAD, number of attempts and adjustments, the necessity to increase isoflurane concentrations to maintain a surgical plane of anaesthesia, arterial blood gas values, gross laryngeal evaluation, and laryngotracheal histopathology.

RESULTS

Both techniques resulted in elevated arterial pCO₂ levels, but the v-gel was associated with more elevated pCO₂ in comparison with EEI (P=0.045). Airway trauma was histologically present but clinically negligible in both groups, with no statistically significant differences observed between techniques (P>0.05). Placement time of the v-gel was significantly faster (P=0.003) and required less technical skill than EEI, but was more easily displaced when changing the animal's position (P=0.004).

CONCLUSION

The v-gel is a practical alternative to EEI for securing the airway of healthy spontaneously ventilating rabbits, provided a capnograph is utilised to ensure continuous placement. Both airway techniques appear safe and effective with few complications, as long as intermittent positive pressure ventilation can be employed to correct hypercapnia.

A Randomized Controlled Trial Comparing Ambu AuraGain and i-gel in Young Pediatric Patients

Supraglottic airway devices have been increasingly used because of their several advantages. Previous studies showed that the small-sized i-gel provides effective ventilation for young pediatric patients; however, few studies have reported the use of AuraGain in these patients. Herein, we compared the clinical performance of AuraGain and i-gel in young pediatric patients aged between 6 months and 6 years old and weighing 5–20 kg, who were scheduled to undergo extremity surgery under general anesthesia. In total, 68 patients were enrolled and randomly allocated into two groups: AuraGain group and i-gel group. The primary outcome was the requirement of additional airway maneuvers. We also analyzed insertion parameters, fiberoptic bronchoscopic view, oropharyngeal leak pressure, and peri-operative adverse effects. Compared with the AuraGain group, the i-gel group required more additional airway maneuvers during the placement of the device and maintenance of ventilation. The fiberoptic view was better in the AuraGain group than in the i-gel group. However, the oropharyngeal leak pressure was higher in the i-gel group. AuraGain might be a better choice over i-gel considering the requirement of additional airway maneuvers. However, when a higher oropharyngeal leak pressure is required, the i-gel is more beneficial than AuraGain.

Dexmedetomidine reduces sevoflurane EC50 for supraglottic airway device insertion in spontaneously breathing morbidly obese patients

Purpose: This study aimed to assess the effect of intravenous dexmedetomidine (DEX) on sevoflurane EC₅₀ for supraglottic airway device (SAD) insertion in spontaneously breathing morbidly obese patients.

Patients and methods: Thirty-eight morbidly obese patients with a body mass index 40–57 kg/m² who were scheduled for bariatric surgery under general anesthesia requiring tracheal intubation were randomly allocated to two groups receiving the different treatments: group S, saline was given intravenously, and group D, a bolus dose of DEX 1 μg/kg was administered intravenously over 10 mins, followed by intravenous DEX infusion at a rate of 0.5 μg/kg/h. Five percent sevoflurane was initially inhaled for anesthesia induction and then end-tidal expiratory sevoflurane concentration (ET_sev) was adjusted to a target value as to the modified Dixon’s up-and-down method. Patients’ response to SAD insertion was classified as “movement” or “no movement”. The average of the midpoints of all crossover points was defined as calculated sevoflurane EC₅₀ for successful SAD insertion. Furthermore, the probit regression analysis was used to determine sevoflurane end-tidal concentrations where 50% (EC₅₀) and 95% (EC₉₅) insertions of SAD were successful. After the observation was completed, flexible bronchoscope-guided intubation was performed through the SAD.

Results: The calculated sevoflurane EC₅₀ for successful SAD insertion was significantly lower in group D than in group S (1.75±0.32% vs 2.92±0.26%, p<0.001). By the probit regression analysis, EC₅₀ and EC₉₅ of sevoflurane for successful SAD insertion were 1.59% (95% CI, 1.22–1.90%) and 2.15% (95% CI, 1.86–3.84%) in group D, respectively, and 2.81% (95% CI, 2.35–3.29%) and 3.32% (3.02–6.74%) in group S.

Conclusion: When sevoflurane inhalational induction is performed in spontaneous breathing morbidly obese patients, intravenous DEX can reduce sevoflurane EC₅₀ for successful SAD insertion by about 40%.

Chinese Clinical Trial Registry: No. ChiCTR1800016868

The effect of i-gel® insertion on the accuracy of cricothyroid membrane identification in adult females: a prospective observational study

BACKGROUND

Identification of the cricothyroid membrane is frequently inaccurate in females because of less distinct anatomy compared with males. Supraglottic airway devices cause ventral displacement of the laryngeal structures. We investigated if this would impact on the accuracy of cricothyroid membrane identification using palpation.

METHODS

We recruited 64 adult females who underwent assessment by volunteer participants with and without a sited i-gel^® supraglottic airway device. The primary outcome was accuracy in identifying the cricothyroid membrane. Secondary outcomes included distance from participant estimate to actual cricothyroid membrane location and perceived difficulty using a visual analogue scale. Ultrasound images were analysed to determine the effect of the i-gel^® on the anatomical structures relevant to cricothyroidotomy.

RESULTS

The cricothyroid membrane was identified correctly in 42/64 subjects with the i-gel^® in place (66%) vs 23/64 of controls (36%; P<0.001, mean difference 30%; 95% confidence interval, 12-47%). VAS (P<0.001) and distance to the cricothyroid membrane (P<0.001) decreased in the intervention group. Analysis of the ultrasound image series showed a reduction in the mean angle between the cricothyroid membrane and anterior wall of the trachea in the i-gel^® group, because of the more ventral position of the cricoid cartilage compared with control images (166° vs 151°, P<0.001).

CONCLUSIONS

The presence of the i-gel^® improved accuracy of identifying the cricothyroid membrane using palpation in females. The cricoid cartilage was pushed ventrally by the i-gel^® in the hypopharynx, creating a more palpable prominence. It may therefore be advantageous to retain a sited supraglottic airway, rather than remove it, before performing emergency cricothyroidotomy.

Comprehensive evaluation of manikin-based airway training with second generation supraglottic airway devices

Background

Supraglottic airway devices (SADs) are an essential second line tool during difficult airway management after failed tracheal intubation. Particularly for such challenging situations the handling of an SAD requires sufficient training. We hypothesized that the feasibility of manikin-based airway management with second generation SADs depends on the type of manikin.

Methods

Two airway manikins (TruCorp AirSim^® and Laerdal Resusci Anne^® Airway Trainer™) were evaluated by 80 experienced anesthesia providers using 5 different second generation SADs (LMA^® Supreme™ [LMA], Ambu^® AuraGain™, i-gel^®, KOO™-SGA and LTS-D™). The primary outcome of the study was feasibility of ventilation measured by assessment of the manikins' lung distention. As secondary outcome measures, oropharyngeal leakage pressure (OLP), ease of gastric tube insertion the insertion time, position and subjective assessments were evaluated.

Results

Ventilation was feasible with all combinations of SAD and manikin. By contrast, an OLP exceeding 10 cm H₂O could be reached with most of the SADs in the TruCorp but with the LTS-D only in the Laerdal manikin. Gastric tube insertion was successful in above 90% in the Laerdal vs 87% in the TruCorp manikin (P<0.009). Insertion times differed significantly between manikins. The SAD positions were better in the Laerdal manikin for LMA, Ambu, i-gel and LTS-D. Participant's assessments were superior in the Laerdal manikin for LMA, Ambu, i-gel and KOO-SGA.

Conclusions

Ventilation is possible with all combinations. However, manikins are variable in their ability to adequately represent additional functions of second generation SADs. In order to achieve the best performance during training, the airway manikin should be chosen depending on the SAD in question.

A new second-generation supraglottic airway device (Ambu® AuraGain•) versus intubating laryngeal mask airway as conduits for blind intubation - A prospective, randomised trial

Background and Aims:

The Ambu^® AuraGain^• is a new single-use supraglottic airway device with gastric channel, designed to facilitate intubation. The study aimed to assess the success rates of proper placement and intubation using Ambu^® AuraGain^• compared with intubating laryngeal mask airway (ILMA).

Methods:

One hundred and twenty patients (18–60 years) were enrolled into this prospective, randomised, comparative study. After inducing general anaesthesia, appropriate size ILMA (group I)/Ambu^® AuraGain^• (group A) was placed as per the manufacturer's recommendations and correct placement was confirmed. Appropriate size endotracheal tube was passed through the device. The success rate of insertion and intubation, number of attempts, Cormack–Lehane grading before insertion and haemodynamics were recorded. Data were analysed using Mantel–Haenszel Chi-square test, Student's t-test and Fisher's exact test.

Results:

Demographic and airway parameters were uniformly distributed in both the groups. The success rate for insertion was 100% in both devices. The success rate for intubation was 96.6% (58/60) in group I and 36.6% in group A (P < 0.001). In group I, patients with mean thyromental distance >7.62 ± 0.75 cm had higher successful intubation compared with patients with mean thyromental distance <5.25 ± 0.35 cm (P = 0.014). Cormack–Lehane grading did not correlate with intubation attempts or success rate in group I (P = 0.45), whereas in group A the rate of successful blind intubation with Cormack–Lehane grade 1 was 50% (19/38).

Conclusion:

Both devices have 100% insertion success, though Ambu^® AuraGain^• has lower success rate for facilitating intubation compared with ILMA.

Supraglottic airway devices in difficult airway management: a retrospective cohort study of 658,104 general anaesthetics registered in the Danish Anaesthesia Database

Indications for using supraglottic airway devices have widened over time and they now hold a prominent role in guidelines for difficult airway management. We aimed to describe the use of supraglottic airway devices in difficult airway management. We included adult patients undergoing general anaesthesia registered in the Danish Anaesthesia Database from 2008 to 2012 whose airway management had been recorded as difficult, defined as: ≥ 3 tracheal intubation attempts; failed tracheal intubation; or difficult facemask ventilation. In the Danish Anaesthesia Database, a separate difficult airway management module requires the technique used in each successive airway management attempt to be recorded. The primary aim of the study was to describe the use of supraglottic airway devices in cases of difficult airway management. Secondary aims were to examine success rates of supraglottic airway devices in difficult airway management cases, and specifically in the cases of 'cannot intubate, cannot facemask ventilate'. Difficult airway management occurred in 4898 (0.74% (95%CI 0.72-0.76%)) of 658,104 records of general anaesthesia. Supraglottic airway devices were used or use was attempted in 607 cases of difficult airway management (12.4% (95%CI 11.5-13.3%)), and were successful in 395 (65.1% (95%CI 61.2-68.8%)) cases. In 'cannot intubate, cannot facemask ventilate' situations, supraglottic airway devices were used in 86 (18.9% (95%CI 15.6-22.8%)) of 455 records and were successful in 54 (62.8% (95%CI 52.2-72.3%)) cases. We found that supraglottic airway devices are not widely used in the management of the difficult airway despite their prominent role in difficult airway management guidelines.

Comparison of plasma propofol concentration for apnea, response to mechanical ventilation, and airway device between endotracheal tube and supraglottic airway device in Beagles

The relationships between propofol plasma concentrations and the pharmacodynamic endpoints may differ according to a type of airway device. To clarify these relationships in different airway devices would be useful to avoid the complication such as apnea and intraoperative awareness. The aim of this study was to investigate the influence of difference of airway device on propofol requirement during maintenance of anesthesia in dogs. We compared the influence of airway devices on the plasma propofol concentrations for apnea, response to mechanical ventilation, and response to airway device between endotracheal tube (ETT) and supraglottic airway device (SGAD) in Beagles. The pharmacodynamic effects were repeatedly assessed at varying propofol concentrations. The plasma concentrations (mean ± SD) of propofol in the ETT and SGAD groups were 10.2 ± 1.8 and 10.9 ± 2.4 µg/ml for apnea (P=0.438), 7.9 ± 1.2 and 7.4 ± 1.5 µg/ml for response to mechanical ventilation (P=0.268), and 5.2 ± 0.7 and 5.4 ± 1.5 µg/ml for response to airway device (P=0.580), respectively. Required propofol concentration during maintenance of anesthesia may be similar between ETT and SGAD. Without moderate to strong stimuli such as airway device insertion or painful stimulation during surgery, the type of airway device may have little impact on required propofol concentration during maintenance of anesthesia in dogs.

Neuromuscular blockers and reversal agents and their impact on anesthesia practice

Neuromuscular blockers have long been an intricate part of the anesthesia regimen. The scientific progress in pharmacology and physiology has strengthened their clinical relevance, has helped to delineate with precision their medical role, and has enhanced the safety and effectiveness of their use. New frontiers in research will define further the role of these agents in modern anesthesia practice and guide their expanding and discrete clinical applications.

Supraglottic airway device versus a channeled or non-channeled blade-type videolaryngoscope for accidental extubation in the prone position: A randomized crossover manikin study

BACKGROUND

It is very rare but challenging to perform emergency airway management for accidental extubation in a patient whose head and neck are fixed in the prone position when urgently turning the patient to the supine position would be unsafe. The authors hypothesized that tracheal intubation with a videolaryngoscope would allow effective airway rescue in this situation compared with a supraglottic airway device and designed a randomized crossover manikin study to test this hypothesis.

METHODS

The authors compared airway rescue performances of the 3 devices-the ProSeal laryngeal mask airway (PLMA; Teleflex Medical, Westmeath, Ireland) as a reference; the Pentax AWS (AWS; Nihon Kohden, Tokyo, Japan) as a channeled blade-type videolaryngoscope; and the McGRATH videolaryngoscope (McGRATH; Medtronic, Minneapolis, MN) as a nonchanneled blade type in a manikin fixed to the operating table in the prone position. Twenty-one anesthesiologists performed airway management on the prone manikin with the 3 devices, and the time required for intubation/ventilation and the success rates were recorded.

RESULTS

The median (range) intubation/ventilation times with the PLMA, AWS, and McGRATH were 24.5 (13.5-89.5) s, 29.9 (17.1-79.8) s, and 46.7 (21.9-211.7) s, respectively. There was no significant difference in intubation/ventilation times between the PLMA and AWS. The AWS permitted significantly faster tracheal intubation than did the McGRATH (P = 0.006). The success rates with the PLMA (100%) and AWS (100%) were significantly greater than that with the McGRATH (71.4%). Airway management performance of the PLMA and AWS was comparable between devices and better than that of the McGRATH in the prone position.

CONCLUSIONS

Considering that tracheal intubation can provide a more secure airway and more stable ventilation than the PLMA, re-intubation with a channeled blade-type videolaryngoscope such as the AWS may be a useful method of airway rescue for accidental extubation in patients in the prone position.

Current practice patterns of supraglottic airway device usage in paediatric patients amongst anaesthesiologists: A nationwide survey

Background and Aims:

Supraglottic airway devices (SGADs) are increasingly being used for airway management in paediatric patients undergoing general anaesthesia. This survey was designed to assess the nationwide practice patterns of SGAD usage in paediatric patients.

Methods:

A questionnaire of 28 questions was circulated amongst 16,532 members of the Indian Society of Anaesthesiologists through online survey engine Google Forms^® and served manually to 500 delegates attending the Asian Society of Paediatric Anaesthesiologists conference 2017. Percentage, mean and standard deviation were calculated using Microsoft Excel 2016 (Redmond, WA, USA).

Results:

Four hundred and five (2.3%) valid responses were obtained. The most commonly used device was i-gel^© (60.74%). Three hundred and four (75.06%) respondents had access to second-generation SGADs. Second-generation devices (60.74%) were more commonly used than first-generation devices (39.26%). Anaesthesiologists utilised SGADs in various challenging scenarios such as in the difficult airway (53.33%), remote locations (55.47%), ophthalmologic (38.77%) and long-duration surgeries (17.53%). Sixty per cent respondents did not use SGADs in laparoscopic surgery. Disposable SGADs were reused by 77.28% respondents. Oropharyngeal seal and intracuff pressures were not measured by 86.91% and 56.92% respondents, respectively. Difficulty in size selection (84.19%), securing position (82.22%) and maintaining unobstructed ventilation (78.76%) were common problems encountered while using SGADs.

Conclusion:

Although there is a widespread use of second-generation SGADs in Indian paediatric anaesthesia, safe practices such as using capnography, measurement of oropharyngeal seal pressure, cuff pressure and appropriate disinfection are lacking.

Optimum end-tidal concentration of sevoflurane to facilitate supraglottic airway device insertion with propofol at induction allowing spontaneous respiration in obese patients: A prospective observational study

Obese patients are more likely to encounter with difficult airway management, and supraglottic airway device has been adopted to facilitate tracheal intubation. The optimum anesthetic concentration for obese patients to insert a supraglottic airway device with spontaneous respiration has not been investigated. This study was designed to determine the end-tidal concentration of sevoflurane that would provide acceptable condition for supraglottic airway device insertion with propofol at induction in obese patients without using neuromuscular blockade.Thirty elective obese patients [body mass index (BMI) 30-50 kg/m] scheduled for bariatric surgery were enrolled in this study. Sevoflurane was inhaled at a concentration of 5% after infusion of 1 mg/kg propofol (within 1 minute) according to lean body weight. The target concentration of sevoflurane was initiated at 2.5% with 0.5% as a step size using a modified Dixon up-and-down method. Five minutes after target concentration achieved, the insertion of supraglottic airway device was attempted.The minimum alveolar concentration of sevoflurane for successful insertion of supraglottic airway device calculated using up-and-down method were 2.25 (0.53) % for obese patients. The values of the effective concentration of sevoflurane for successful supraglottic airway device insertion in 50% (EC50) and 95% (EC95) of the obese patients obtained by probit regression analysis were 2.09% (95% confidence interval 1.48-2.68) and 3.31% (95% confidence interval 2.70-8.12), respectively.We conclude that sevoflurane at a minimum alveolar concentration of 2.25% can provide optimal conditions for insertion of supraglottic airway device with spontaneous respiration in obese patients with 1 mg/kg propofol at induction.

All India Difficult Airway Association 2016 guidelines for the management of anticipated difficult extubation

Extubation has an important role in optimal patient recovery in the perioperative period. The All India Difficult Airway Association (AIDAA) reiterates that extubation is as important as intubation and requires proper planning. AIDAA has formulated an algorithm based on the current evidence, member survey and expert opinion to incorporate all patients of difficult extubation for a successful extubation. The algorithm is not designed for a routine extubation in a normal airway without any associated comorbidity. Extubation remains an elective procedure, and hence, patient assessment including concerns related to airway needs to be done and an extubation strategy must be planned before extubation. Extubation planning would broadly be dependent on preventing reflex responses (haemodynamic and cardiovascular), presence of difficult airway at initial airway management, delayed recovery after the surgical intervention or airway difficulty due to pre-existing diseases. At times, maintaining a patent airway may become difficult either due to direct handling during initial airway management or due to surgical intervention. This also mandates a careful planning before extubation to avoid extubation failure. Certain long-standing diseases such as goitre or presence of obesity and obstructive sleep apnoea may have increased chances of airway collapse. These patients require planned extubation strategies for extubation. This would avoid airway collapse leading to airway obstruction and its sequelae. AIDAA suggests that the extubation plan would be based on assessment of the airway. Patients requiring suppression of haemodynamic responses would require awake extubation with pharmacological attenuation or extubation under deep anaesthesia using supraglottic devices as bridge. Patients with difficult airway (before surgery or after surgical intervention) or delayed recovery or difficulty due to pre-existing diseases would require step-wise approach. Oxygen supplementation should continue throughout the extubation procedure. A systematic approach as briefed in the algorithm needs to be complemented with good clinical judgement for an uneventful extubation.

Air-Q intubating laryngeal airway: A study of the second generation supraglottic airway device

BACKGROUND AND AIMS

Air-Q intubating laryngeal mask airway (ILA) is used as a supraglottic airway device and as a conduit for endotracheal intubation. This study aims to assess the efficacy of the Air-Q ILA regarding ease of insertion, adequacy of ventilation, rate of successful intubation, haemodynamic response and airway morbidity.

METHODS

Sixty patients presenting for elective surgery at our Medical College Hospital were selected. Following adequate premedication, baseline vital parameters, pulse rate and blood pressure were recorded. Air-Q size 3.5 for patients 50-70 kg and size 4.5 for 70-100 kg was selected. After achieving adequate intubating conditions, Air-Q ILA was introduced. Confirming adequate ventilation, appropriate sized endotracheal tube was advanced through the Air-Q blindly to intubate the trachea. Placement of the endotracheal tube in trachea was confirmed.

RESULTS

Air-Q ILA was successfully inserted in 88.3% of patients in first attempt and 11.7% patients in second attempt. Ventilation was adequate in 100% of patients. Intubation was successful in 76.7% of patients with Air-Q ILA. 23.3% of patients were intubated by direct laryngoscopy following failure with two attempts using Air-Q ILA. Post-intubation the change in heart rate was statistically significant (P < 0.0001). 10% of patients were noted to have a sore throat and 5% of patients had mild airway trauma.

CONCLUSION

Air-Q ILA is a reliable device as a supraglottic airway ensuring adequate ventilation as well as a conduit for endotracheal intubation. It benefits the patient by avoiding the stress of direct laryngoscopy and is also superior alternative device for use in a difficult airway.

Comparison of three supraglottic airway devices for airway rescue in the prone position: A manikin-based study

BACKGROUND

Accidental extubation during surgery in prone position can be life-threatening. Supraglottic airway devices (SAD) have been used successfully in such situations to rescue the airway. However, which SAD would be most appropriate in this setting has not been described in the literature.

AIMS

The aim of our study was to determine the most appropriate SAD for securing airway in a prone position during accidental extubation.

MATERIALS AND METHODS

In the study, Airway Trainer (Laerdal) manikin was used for studying insertion of three SADs; I-gel, Laryngeal Mask Airway ProSeal™ (PLMA) and LMA Classic™ (CLMA) in the prone position. Forty anesthesia resident doctors participated in this study. The time taken for insertion; ease of insertion and ventilation; bronchoscopic view; and insertion score were compared among the three groups.

RESULTS

The time taken for I-gel insertion was significantly lesser (12.89 ± 3.94 seconds) as compared to CLMA (17.07 ± 3.5 seconds) and PLMA (25 + 4.78 seconds). Least resistance was encountered in the insertion of I-gel, while maximum resistance was experienced in PLMA group (22.5% vs. 90%). The maneuver required for optimal positioning was observed in 27.5% of PLMA insertion, 2.5% in CLMA while no maneuver was required in any of the I-gel insertion. Ease of ventilation was comparable in all three SADs. The bronchoscopic view and insertion score were significantly higher with I-gel as compared to CLMA and PLMA.

CONCLUSION

All three SADs were successful as rescue devices during accidental extubation in the prone position. However, the ease of insertion was maximum with I-gel, followed by CLMA and PLMA.

A prospective study to evaluate and compare laryngeal mask airway ProSeal and i-gel airway in the prone position

Background:

Prone position is commonly used to provide surgical access to a variety of surgeries. In view of the advantages of induction of anesthesia in the prone position, we conducted a randomized study to evaluate and compare ProSeal laryngeal mask airway (LMA) and i-gel in the prone position.

Materials and Methods:

Totally, 40 patients of either sex as per American Society of Anesthesiologists physical status I or II, between 16 and 60 years of age, scheduled to undergo surgery in prone position were included in the study. After the patients positioned themselves prone on the operating table, anesthesia was induced by the standard technique. LMA ProSeal was used as an airway conduit in group 1 while i-gel was used in group 2. At the end of surgery, the airway device was removed in the same position.

Results:

Insertion of airway device was successful in first attempt in 16, and 17 cases in ProSeal laryngeal mask airway (PLMA) and i-gel groups, respectively. A second attempt was required to secure the airway in 4 and 3 patients in PLMA and i-gel groups, respectively. The mean insertion time was 21.8 ± 2.70 s for group 1 and 13.1 ± 2.24 s for group 2, the difference being statistically significant (P < 0.05). The mean seal pressure in group 1 was 36 ± 6.22 cm H₂ O and in group 2 was 25.4 ± 3.21 cm H₂ O. The difference was statistically significant (P < 0.05). 13 patients in group 1 had fiberoptic bronchoscopy (FOB) grade 1 while it was 6 for group 2. The remaining patients in both groups had FOB grade 2.

Conclusion:

Insertion of supraglottic airways and conduct of anesthesia with them is feasible in the prone position. The PLMA has a better seal while insertion is easier with i-gel.

I-gel versus laryngeal mask airway-Proseal: Comparison of two supraglottic airway devices in short surgical procedures

BACKGROUND AND AIMS

Supraglottic airway devices have been established in clinical anesthesia practice and have been previously shown to be safe and efficient. The objective of this prospective, randomized trial was to compare I-Gel with LMA-Proseal in anesthetized spontaneously breathing patients.

MATERIAL AND METHODS

Sixty patients undergoing short surgical procedures were randomly assigned to I-gel (Group I) or LMA- Proseal (Group P). Anesthesia was induced with standard doses of propofol and the supraglottic airway device was inserted. We compared the ease and time required for insertion, airway sealing pressure and adverse events.

RESULTS

There were no significant differences in demographic and hemodynamic data. I-gel was significantly easier to insert than LMA-Proseal (P < 0.05) (Chi-square test). The mean time for insertion was more with Group P (41 + 09.41 secs) than with Group I (29.53 + 08.23 secs) (P < 0.05). Although the airway sealing pressure was significantly higher with Group P (25.73 + 02.21 cm of H2O), the airway sealing pressure of Group I (20.07 + 02.94 cm of H2O) was very well within normal limit (Student's t test). The success rate of first attempt insertion was more with Group I (P < 0.05). There was no evidence of airway trauma, regurgitation and aspiration. Sore throat was significantly more evident in Group P.

CONCLUSION

I-Gel is a innovative supraglottic device with acceptable airway sealing pressure, easier to insert, less traumatic with lower incidence of sore throat. Hence I-Gel can be a good alternative to LMA-Proseal.

Anaesthetic Management of a Patient with Pseudo-TORCH Syndrome

BACKGROUND

Pseudo-TORCH syndrome is a rare, chronic disorder that is characterised by dimorphic features such as microcephaly, intracranial calcification, seizures, mental retardation, hepatosplenomegaly and coagulation disorders.

CASE REPORT

We present the anaesthetic management of a forty day-old boy with Pseudo-TORCH syndrome during magnetic resonance imaging. Microcephaly, growth failure, high palate and bilateral rales in the lungs were detected in pre-anaesthetic physical examination. The peripheral oxygen saturation was 88-89% in room-air and was 95% in a hood with 5 L/min oxygen. We planned general anaesthesia to ensure immobility during magnetic resonance imaging. After standard monitoring, general anaesthesia was induced with 8% sevoflurane in 100% O2. After an adequate depth of anaesthesia was reached, we inserted a supraglottic airway device to avoid intubation without the use of a muscle relaxant.

CONCLUSION

In patients with Pseudo-TORCH syndrome, the perioperative anaesthetic risk was increased. We believe that using a supraglottic airway device to secure the airway is less invasive than intubation, and can be performed without the need of muscle relaxants.