Laryngeal mask airway indications: new frontiers for second-generation supraglottic airways

Comparison of gum elastic bougie-guided insertion of LMA ProtectorTM versus the conventional method in achieving oesophagal patency - A randomised comparative study

Background and Aims

The passage of a Ryle's tube through the drain port on the laryngeal mask airway (LMA) ProtectorTM has been reported to be arduous despite the larger gastric channel. There are no studies on the evaluation of the guided insertion of LMA ProtectorTM to achieve adequate gastrointestinal drainage function.

Methods

This randomised study included 132 patients who underwent surgery under general anaesthesia. The gum elastic bougie (GEB)-guided insertion of LMA ProtectorTM (group I) was compared with the conventional method (group II), and the alignment of the tip of the drain tube with the oesophagus was assessed. The insertion characteristics of the device, accuracy of LMA ProtectorTM placement, haemodynamic parameters, and post-operative airway morbidity following the insertion of the device were also compared between the two groups.

Results

The first-attempt success rate for the placement of LMA ProtectorTM and the patency of oesophagus was higher in group I patients than in group II (100% vs 84.8%; P < 0.001). However, the time taken for device insertion and associated haemodynamic changes were significantly longer in group I. The patients in group I had better visualisation of laryngeal structures. The GEB-assisted insertion of LMA ProtectorTM resulted in less incidence of blood staining at the cuff of the device.

Conclusion

GEB-guided insertion of LMA ProtectorTM achieved better oesophageal patency than the conventional insertion method. This method also had higher first-attempt success at the placement of the device and was observed to be less traumatic.

Second-generation laryngeal mask airway as an alternative to endotracheal tube in prolonged laparoscopic abdominal surgery: a comparative analysis of intraoperative gas exchanges

Introduction

Laryngeal mask airway (LMA), which is used in difficult airway maintenance conditions during emergencies, is rarely used in prolonged surgery despite its advantages over endotracheal tube (ETT). In this study, we conducted a comparative analysis of intraoperative gas exchanges between second-generation LMA and ETT during prolonged laparoscopic abdominal surgery.

Methods

Prolonged surgery was defined as a surgery lasting more than 2 h. In total, 394 patients who underwent laparoscopic liver resection via either second-generation LMA or ETT were retrospectively analysed. The following parameters were compared between the two groups of patients: end-tidal pressure of carbon dioxide (ETCO2), tidal volume (TV), respiratory rate (RR), peak inspiratory pressure (PIP), arterial partial pressure of carbon dioxide (PaCO2), pH and ratio of arterial partial pressure of oxygen to fractional inspired oxygen (PFR) during surgery. In addition, the incidence of postoperative pulmonary complications (PPCs), including pulmonary aspiration, was compared.

Results

The values of ETCO2, TV, RR and PIP during pneumoperitoneum were comparable between the two groups. Although PaCO2 at 2 h after induction was higher in patients in the LMA group (40.5 vs. 38.5 mmHg, P < 0.001), the pH and PFR values of the two groups were comparable. The incidence of PPC was similar.

Conclusion

During prolonged laparoscopic abdominal surgery, second-generation LMA facilitates adequate intraoperative gas exchange and may serve as an alternative to ETT.

Supraglottic Airway Devices with Vision Guided Systems: Third Generation of Supraglottic Airway Devices

Supraglottic airway devices are currently widely used for airway management both for anaesthesia and emergency medicine. First-generation SADs only had a ventilation channel and did not provide protection from possible aspiration of gastric content if regurgitation occurred. Second-generation SADs are equipped with a gastric channel to allow the insertion of a gastric catheter and suctioning of gastric content. Additionally, the seal was improved by a change in the shape of the cuff. Some second-generation SADs were also designed to allow for intubation through the lumen using fiberscopes. Although the safety and efficacy of use of SADs are very high, there are still some issues in terms of providing an adequate seal and protection from possible complications related to misplacement of SAD. New SADs which allow users to choose the insertion scope and control the position of SAD can overcome those problems. Additionally, the Video Laryngeal Mask Airway may serve as an endotracheal intubation device, offering a good alternative to fibre-optic intubation through second-generation SADs. In this narrative review, we provide knowledge of the use of video laryngeal mask airways and the possible advantages of introducing them into daily clinical practice.

A systematic review and meta-analysis on the efficacy and safety of the Baska mask versus other laryngeal mask airways during general anaesthesia

BACKGROUND

The Baska mask is a supraglottic airway device used during general anaesthesia that combines features from various other devices. This systematic review aims to compare its efficacy and safety with other laryngeal mask airways.

METHODS

Randomised controlled trials were identified by searching PubMed, Scopus, Web of Science and Cochrane Library. RevMan software was used for meta-analysis, with mean difference and risk ratios calculated for continuous and dichotomous data, respectively, along with a 95% confidence interval.

RESULTS

The meta-analysis found that the Baska mask provides a better oropharyngeal seal pressure (mean difference = 7.03; 95% confidence interval = [6.00, 8.07], p < 0.00001) and a higher rate of maximal seal pressure (risk ratio = 18.38; 95% confidence interval = [2.53, 133.47], p = 0.004) compared to other laryngeal mask airways. However, the Baska mask had lower success rates in first-attempt insertion (risk ratio = 0.79; 95% confidence interval = [0.72, 0.86], p < 0.00001) and higher rates of insertion manipulation (risk ratio = 16.64; 95% confidence interval = [5.86, 47.24], p < 0.00001).

CONCLUSION

The Baska mask offers better oropharyngeal seal pressure, but may be more difficult to insert than other laryngeal mask airways, without causing significant delays. The Baska mask appears as safe as other laryngeal mask airways, but larger trials are needed to support these findings.

Supreme laryngeal mask airway for cesarean section under general anesthesia: a 10-year retrospective cohort study

Background

Previous research showed the use of supraglottic airways in obstetric anesthesia. The relevant evidence of laryngeal mask airway (LMA) on maternal and neonatal outcomes is still limited. We aimed to assess the maternal and neonatal outcomes when the LMA Supreme was used for cesarean section under general anesthesia.

Methods

We included all patients who underwent general anesthesia for cesarean section between January 2010 and December 2019. Propensity score matching was used to reduce potential bias from non-random selection of airway intervention. The primary outcome was adverse maternal and neonatal outcomes defined as maternal regurgitation, aspiration, hypoxemia, and low neonatal Apgar scores. Secondary outcomes included patient admission to the intensive care unit, neonate required tracheal intubation, external cardiac massage, and admission to the neonatal intensive care unit.

Results

A total of 723 patients were included in the analysis; of whom, 221 received Supreme laryngeal mask airway (LMA group) and 502 were intubated with an endotracheal tube (ETT group). After propensity score matching, 189 patients remained in each group. No episode of regurgitation and aspiration occurred in both groups. There was no difference in the rates of Apgar score below 7 at 1 min (14.3% LMA group vs. 15.3% ETT group, OR 0.931, 95% CI 0.574 to 1.510, P = 0.772) and 5 min (3.7% vs. 4.2%, OR 0.875, 95% CI 0.324 to 2.365, P = 0.792). No difference was observed in the secondary outcomes between the two groups.

Conclusion

The LMA Supreme was not associated with higher adverse maternal and neonatal outcomes when compared to an endotracheal tube for cesarean section under general anesthesia. It might be considered an alternative to tracheal intubation in obstetric practice.

[Update 2022: interdisciplinary statement on airway management with supraglottic airway devices in pediatric emergency medicine-The laryngeal mask is and remains state of the art : Joint statement of the Institute for Emergency Medicine and Medicine Management (INM), the University Clinic Munich, LMU Munich, Germany, the Working Group for Pediatric Critical Care and Emergency Medicine of the German Interdisciplinary Society for Critical Care and Emergency Medicine (DIVI), the Medical Directors of Emergency Medical Services in Bavaria (ÄLRD), the Scientific Working Group for Pediatric Anesthesia (WAKKA) of the German Society for Anesthesiology and Intensive Care Medicine (DGAI), the Scientific Working Group for Emergency Medicine of the German Society for Anesthesiology and Intensive Care Medicine (DGAI) and the Society of Neonatology and Pediatric Critical Care Medicine (GNPI)]

BACKGROUND

Airway management with supraglottic airway devices (SGA) in life-threatening emergencies in children is increasingly being used. Different specifications of laryngeal masks (LM) and the laryngeal tube (LT) are commonly used devices for this purpose. We present a literature review and interdisciplinary consensus statement of different societies on the use of SGA in pediatric emergency medicine.

MATERIAL AND METHODS

Literature review in the PubMed database and classification of studies according to the criteria of the Oxford Centre for Evidence-based Medicine. Levels and consensus finding within the group of authors.

RESULTS

The evidence for successful applications of the various types of LM is significantly higher than for LT application. Reported smaller series of successful applications of LT are currently limited to selected research groups and centers. Especially for children below 10 kg body weight there currently exists insufficient evidence for the successful application of the LT and therefore its routine use cannot be recommended. SGAs used for emergencies should have a gastric drainage possibility.

DISCUSSION

Considering the scientific data and the large clinical experience with the LM in medical routine and emergency situations in children currently only the LM can be recommended for alternative (i.e., non-intubation) emergency airway management in children. If alternative airway management is part of a local emergency strategy, the LM should be provided in all pediatric sizes (1, 1½, 2, 2½, 3) for out of hospital use and in hospital emergency use and all users should regularly be trained in its application.

Prewarming non-inflatable cuff laryngeal mask for mechanical ventilation: A systematic review and meta-analysis with trial sequential analysis

BACKGROUND

Non-inflatable cuff laryngeal masks are generally composed of thermoplastic material. The thermoplastic nature of the non-inflatable cuff will become soft and match the laryngeal anatomy better as it reaches body temperature after intubation. This meta-analysis aims to evaluate the clinical validity of prewarming non-inflatable cuff laryngeal mask before insertion.

METHODS

We searched PubMed, Cochrane Library, Embase, Web of Science, Ovid Medline, CNKI, Wan Fang Database and VIP Database to find randomized controlled trials (RCTs) researching the clinical validity of prewarming non-inflatable cuff laryngeal mask. The retrieval time is up to June 2022. Articles published in the English and Chinese languages were considered. Quality assessment was conducted with the Cochrane Collaboration's tool and GRADE (Grading of Recommendations Assessment, Development and Evaluation) method. Subgroup analyses and trial sequential analysis (TSA) were performed to control the risk of random errors. Publication bias was assessed by funnel plots and Egger's regression test. The outcomes included sealing pressure immediately after successful ventilation, the first-attempt intubation success rate and the incidence of postoperative pharyngeal pain.

RESULTS

Eight RCTs evaluating 683 patients were identified. Pooled results showed that compared to the control group, prewarming non-inflatable cuff laryngeal mask provided a higher sealing pressure immediately after successful ventilation (mean difference: 1.73 cm H2O; 95% confidence interval [CI]: 0.95-2.52; P < .0001; I2 = 16; high quality), higher first-attempt intubation success rate (risk ratio [RR]: 1.05; 95% CI: 1.01-1.09; P = .01; I2 = 26%; high quality, number needed to treat [NNT] = 22 [95% CI 12.5-100]) and lower incidence of postoperative pharyngeal pain (RR: 0.59, 95% CI: 0.46-0.75; P < .0001; I2 = 0; high quality, NNT = 6 [95% CI 4.17-9.09]). The results were confirmed by TSA.

CONCLUSION

Prewarming non-inflatable cuff laryngeal mask could provide better mechanical ventilation efficiency with higher sealing pressure, a higher first-attempt intubation success rate and a lower incidence of postoperative pharyngeal pain.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42021245350.

Tracheal intubation using intubating laryngeal tube iLTS-D™ and LMA Fastrach™ in 99 adult patients: A prospective multicentric randomised non-inferiority study

STUDY OBJECTIVE

This study aimed to investigate the overall success of tracheal intubation using the intubating Laryngeal Tube Suction-Disposable (iLTS-D™, VBM, Sulz a. N., Germany) compared to the Laryngeal Mask Airway (LMA) Fastrach™ (Teleflex, Athlone, Ireland). We hypothesised that the iLTS-D™ would be non-inferior to the LMA Fastrach™ for tracheal intubation and ventilation.

DESIGN

Multicentric, non-inferiority, randomised controlled study.

SETTING

Operating rooms from two tertiary and one secondary centre in Switzerland from January 2017 to July 2019. The investigators were trained anaesthetists with extensive experience with laryngeal masks but limited to laryngeal tubes. The study was discontinued after the planned interim analysis.

PATIENTS

Ninety-nine adult patients were included after randomisation. The inclusion criteria were American Society of Anesthesiologists physical status 1 to 3 in patients scheduled for elective surgery requiring tracheal intubation. Patients with a history of difficult intubation were excluded.

INTERVENTION(S)

After anaesthesia induction and once neuromuscular blockade was obtained, ventilation was initiated, and tracheal intubation was performed through the randomised device with the flexible endoscope tip placed proximally to the tip of the tracheal tube (visualised blind intubation).

MEASUREMENTS

The primary outcome was the intubation success rate after two attempts. The secondary outcomes were time to intubation, successful ventilation rate, time to achieve ventilation, and gastric access success rate.

MAIN RESULTS

The overall intubation success rate was significantly higher in the Fastrach™ group than in the iLTS-D™ group (91.8% vs 70.0%, p = 0.006). No difference was found in the ventilation success rate (94% for iLTS-D™ and 100% for LMA Fastrach™ [p = 0.829]). The time to achieve ventilation and intubation were similar between the groups. No major airway complications were noted.

CONCLUSIONS

Although both supraglottic devices provided the same effective ventilation rate, the LMA Fastrach™ was superior to the iLTS-D™ as a conduit for intubation in 99 adult patients without a known difficult intubation. These preliminary results need to be confirmed in studies that include a larger population.

TRIAL REGISTRATION

Clinicaltrials.gov, 21.09.2016, Identification Number NCT02922595.

Comparison of I-gel and LMA Protector in Laparoscopic Cholecystectomy: A Randomized Controlled Trial

Aims

Comparison of the use of I-gel and Laringeal Mask Airway (LMA) Protector in laparoscopic cholecystectomy regarding the time and ease of insertion for supraglottic airway devices (SAD) and gastric tube (GT), airway sealing capacity, and postoperative complications.

Patients and Methods

Sixty-four American Society of Anaesthesiologists (ASA) I-III patients undergoing laparoscopic cholecystectomy were randomly allocated into two groups. After anesthesia induction, LMA Protector was inserted in Group LPRO (LMA Protector) (n = 33) and I-gel was inserted in Group IGEL (I-gel) (n = 31) patients. Time of SAD insertion, number of attempts, time, and ease of GT insertion were recorded. The peak inspiratory pressure (PIP) and oropharyngeal leak pressure (OLP) were measured at the time of SAD insertion, 10 min after insertion, 10 min after pneumoperitoneum, and just before the termination of pneumoperitoneum. The presence of bloodstains on SAD, sore throat, hoarseness, nausea, and pain in swallowing was assessed postoperatively. A P value of < 0.05 was accepted as statistically significant.

Result

Two patients in Group LPRO needed endotracheal intubation and were excluded from the study. The SAD insertion time was shorter in Group IGEL than in Group LPRO (13 ± 7.4 s vs. 18.8 ± 9.8 s). The number of attempts and success rate on the first attempt were similar in both groups. GT insertion time was shorter in Group IGEL than Group LPRO (11 ± 7.7 s vs. 21 ± 11 s). The insertion of GT was easier in Group IGEL. The OLP levels decreased during the pneumoperitoneum in Group LPRO while they remained constant in Group IGEL.

Conclusion

We observed that I-gel offers more stable airway sealing and easier GT insertion advantages when compared with LMA Protector in laparoscopic cholecystectomy.

Pre-shaped supraglottic airway devices offer an alternative to endotracheal intubation for airway management of postburn neck contracture: A case series

Background and Aims:

Moderate to severe postburn contractures (PBCs) of the neck lead to multiple areas of difficulty in airway management. Awake flexible fiberscope guided intubation with cuffed endotracheal tube (ETT) is considered the “gold standard” for securing the airway in these cases. Supraglottic airway devices (SADs), if at all used, are used either as rescue devices or as conduits for ETT. This case series looks at the possibility of using SADs as a planned airway securing device in these cases.

Material and Methods:

We managed 24 cases of moderate to severe PBC neck using six types of pre shaped SADs as the first choice airway device. These SADs were placed after either airway topicalization (19 cases) or general anesthesia (GA) (5 cases). Once SAD placement was confirmed, all the patients received GA and muscle relaxant. Tests for proper placement and function and fiberscopy (conducted in four cases) were performed at various times during the procedure. The SADs were removed once the patients were fully awake.

Results:

SADs could be placed in one attempt in all the cases. The time taken to hand over the patients to surgeons was 12–20 min. SADs maintained their proper placement and function in spite of changing airway dimensions during contracture release. The patients tolerated the SADs well right until the time they were fully awake. The SADs could be successfully removed on the operation table in all the cases.

Conclusion:

Pre shaped SADs secure the airway quickly and are free from the risk of intraoperative displacements and allow uneventful emergence in moderate and severe PBC neck cases and need to be considered as the first choice in these cases.

AutoFlow® versus volume-controlled ventilation for laparoscopic gynecological surgery using LMA® ProSeal™: a randomized controlled trial

Background

During laparoscopic gynecological surgery, increased peak airway pressure (PAWP) can cause airway leak upon ventilation with the LMA® ProSeal™. We hypothesized that compared with the use of volume-controlled ventilation (VCV), the use of the AutoFlow® mode would decrease PAWP and airway leak during laparoscopic gynecological surgery with LMA ProSeal.

Methods

This single-center, randomized, controlled trial allocated 80 adult women undergoing elective laparoscopic gynecological surgery to one of two groups, namely, the AutoFlow group or the VCV group. Ventilation settings for both groups were 8 ml/kg of tidal volume and 5 cmH₂O of positive end-expiratory pressure, and respiratory rate was adjusted to maintain end-tidal carbon dioxide at 35–40 mmHg. Airway leak, PAWP, and other ventilatory parameters and vital signs were recorded at four timepoints (1, 1 min after insertion of the gastric tube; 2, 2 min after intravenous administration of rocuronium 0.6–0.8 mg/kg; 3, 1 min after initiation of pneumoperitoneum; and 4, 1 min after changing to the Trendelenburg position). The primary outcome was PAWP during pneumoperitoneum and in the Trendelenburg position, whereas the secondary outcomes included PAWP at other timepoints and airway leak development. We used the Mann–Whitney U test for PAWP and Fisher’s exact test for comparing airway leak among the groups.

Results

Data from 40 patients in the AutoFlow group and 39 in the VCV group were used for analysis. PAWP at pneumoperitoneum pressure and in the Trendelenburg position was significantly lower in the AutoFlow group than in the VCV group [median (interquartile range), 16 (15–18) cmH₂O vs. 18 (17–19) cmH₂O; P < 0.001]. Similarly, patients in the AutoFlow group showed lower PAWP at the other three timepoints measured. Airway leak occurred in four patients in the AutoFlow group and in two patients in the VCV group; however, this incidence was not significantly different (P = 0.68).

Conclusions

Even though AutoFlow ventilation decreased PAWP, it did not reduce the incidence of airway leak compared with VCV during laparoscopic gynecological surgery with the LMA ProSeal.

Trial registration

UMIN Clinical Trials Registry, identifier UMIN000023173.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01406-6.

Difficult Airway Management in Adult COVID-19 Patients: Statement by the Society of Airway Management

The COVID-19 disease, caused by Coronavirus SARS-CoV-2, often results in severe hypoxemia requiring airway management. Because SARS CoV-2 virus is spread via respiratory droplets, bag-mask ventilation, intubation, and extubation may place health care workers (HCW) at risk. While existing recommendations address airway management in patients with COVID-19, no guidance exists specifically for difficult airway management. Some strategies normally recommended for difficult airway management may not be ideal in the setting of COVID-19 infection. To address this issue the Society for Airway Management (SAM) created a task force to review existing literature and current Practice Guidelines for management of the difficult airway by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. SAM task force created recommendations for management of known or suspected difficult airway in the setting of known or suspected COVID-19 infection. The goal of the task force was to optimize successful airway management while minimizing exposure risk. Each member conducted a literature review on specific clinical practice section utilizing standard search engines (PubMed, Ovid, Google Scholar). Existing recommendations and evidence for difficult airway management in COVID-19 context were developed. Each specific recommendation was discussed among task force members and modified until unanimously approved by all task force members. Elements of AGREE Reporting Checklist for dissemination of clinical practice guidelines were utilized to develop this statement. Airway management in the COVID-19 patient increases HCW exposure risk. and difficult airway management often takes longer, may involve multiple procedures with aerosolization potential, strict adherence to personal protective equipment (PPE) protocols is mandatory to reduce risk to providers. When patient's airway risk assessment suggests awake tracheal intubation is an appropriate choice of technique, procedures that may cause increased aerosolization of secretions should be avoided. Optimal preoxygenation before induction with tight seal facemask may be performed to reduce risk of hypoxemia. Unless the patient is experiencing oxygen desaturation, positive pressure bag-mask ventilation after induction may be avoided to reduce aerosolization. For optimal intubating conditions, patients should be anesthetized with full muscle relaxation. Videolaryngoscopy is recommended as first-line strategy for airway management. If emergent invasive airway access is indicated, we recommend a surgical technique such as scalpel-bougie-tube, rather than an aerosolizing generating procedure, such as transtracheal jet ventilation. This statement represents recommendations by SAM task force for the difficult airway management of adults with COVID-19 with the goal to optimize successful airway management while minimizing the risk of clinician exposure.

Second generation laryngeal mask airway during laparoscopic living liver donor hepatectomy: a randomized controlled trial

The second-generation laryngeal mask airway (LMA) provides a higher sealing pressure than classical LMA and can insert the gastric drainage tube. We investigated the difference in respiratory variables according to the use of second-generation LMA and endotracheal tube (ETT) in laparoscopic living liver donor hepatectomy (LLDH). In this single-blind randomized controlled trial, intraoperative arterial carbon dioxide partial pressure at 2 h after the airway devices insertion (P_aCO_{2_}2h) was compared as a primary outcome. Participants were randomly assigned to the following groups: Group LMA (n = 45, used Protector LMA), or Group ETT (n = 43, used cuffed ETT). Intraoperative hemodynamic and respiratory variables including mean blood pressure (MBP), heart rate (HR), and peak inspiratory pressure (PIP) were compared. Postoperative sore throat, hoarseness, postoperative nausea and vomiting (PONV), and pulmonary aspiration were recorded. The P_aCO_{2_}2h were equally effective between two groups (mean difference: 0.99 mmHg, P = 0.003; 90% confidence limits: − 0.22, 2.19). The intraoperative change in MBP, HR, and PIP were differed over time between two groups (P < 0.001, P = 0.015, and P = 0.039, respectively). There were no differences of the incidence of postoperative complications at 24 h following LLDH (sore throat and hoarseness: P > 0.99, PONV: P > 0.99, and P = 0.65, respectively). No case showed pulmonary aspiration in both groups. Compared with endotracheal tube, second-generation LMA is equally efficient during LLDH. The second-generation LMA can be considered as the effective airway devices for securing airway in patients undergoing prolonged laparoscopic surgery.

Trial Registration This study was registered at the Clinical Trial Registry of Korea (https://cris.nih.go.kr. CRiS No. KCT0003711).

Guided vs. non-guided insertion of Ambu AuraGain™ in edentulous patients

BACKGROUND

Supraglottic airway devices perform more poorly and have lower oropharyngeal leak pressure in edentulous patients than in patients with teeth. The Ambu Aura Gain is a newer second generation supraglottic airway device.

OBJECTIVE

This randomized clinical trial assessed the oropharyngeal leak pressure in edentulous patients using the Ambu Aura Gain with a gastric tube for insertion guidance and without insertion guidance.

MATERIAL AND METHODS

Patients with ASA (American Society of Anesthesiology) physical status I-III were recruited. Primary outcome was oropharyngeal leak pressure after insertion. Secondary outcome parameters were oropharyngeal leak pressure 15 min and 30 min after insertion, insertion time, insertion attempts and glottis view through flexible fiberscope.

RESULTS

In this study 72 patients aged between 51 and 90 years (mean 73 years) were randomly allocated to the "with guidance" (n = 36) or the "without guidance" group (n = 36). Mean (SD) oropharyngeal leak pressure in "with guidance" and "without guidance" group was 24 cm H₂O and 24 cm H₂O (ns), respectively. A difference was found in mean insertion time with guidance versus without guidance group 52 s (45 s) vs. 26 s (15 s) (p < 0.001). No difference was found in any of the other secondary outcome parameters.

CONCLUSION

A guided insertion technique does not improve oropharyngeal leak pressure of the Ambu AuraGain™ in edentulous patients. As the only difference is an increase in insertion time this technique is of no benefit for this population.

CT imaging of extraglottic airway device-pictorial review

Compared to intubation with a cuffed endotracheal tube, extraglottic airway devices (EGDs), such as laryngeal mask airways, are considered less definitive ventilation conduit devices and are therefore often exchanged via endotracheal intubation (ETI) prior to obtaining CT images. With more widespread use and growing comfort among providers, reports have now described use of EGDs for up to 24 h including cases for which clinicians obtained CT scans with an EGD in situ. The term EGD encompasses a wide variety of devices with more complex structure and CT appearance compared to ETI. All EGDs are typically placed without direct visualization and require less training and time for insertion compared to ETI. While blind insertion generally results in functional positioning, numerous studies have reported misplacements of EGDs identified by CT in the emergency department or post-mortem. A CT-based classification system has recently been suggested to categorize these misplacements in six dimensions: depth, size, rotation, device kinking, mechanical blockage of the ventilation opening(s), and injury from EGD placement. Identifying the type of EGD and its correct placement is critically important both to provide prompt feedback to clinicians and prevent inappropriate medicolegal problems. In this review, we introduce the main types of EGDs, demonstrate their appearance on CT images, and describe examples of misplacements.

Time to consider supraglottic airway device oropharyngeal leak pressure measurement more objectively

Oropharyngeal leak pressure (OLP) is considered a measure of successful placement, adequate performance and is a useful comparator between supraglottic airway devices (SADs). OLP measurement is based on the premise that the SAD is sited properly in the hypopharynx after blind placements, but the evidence suggests otherwise. Several limitations and controversies surround OLP. This editorial addresses the uses and pitfalls of OLP, the rationale for and methods of ascertaining OLP, the pros and cons of OLP measurement and newer modalities to improve its accuracy.

Effectiveness of the Baska mask versus the i-gel device in adult patients under general anesthesia: a systematic review protocol

OBJECTIVE

The objective of this review is to evaluate the ease of use, effectiveness of airway management, and incidence of perioperative complications of the Baska mask compared to the i-gel device in adult patients undergoing elective procedures with general anesthesia.

INTRODUCTION

Supraglottic airway devices have been widely used for airway management in patients undergoing various surgical procedures under general anesthesia. The Baska mask and the i-gel device are two commonly used second-generation supraglottic airway devices that offer a noninvasive alternative to the endotracheal tube given the ease of insertion, rapidity, low risk of postoperative complications, and reduced autonomic imbalance during insertion. However, there is a dearth of studies comparing the clinical performance of these two devices.

INCLUSION CRITERIA

This review will consider studies with adults aged 18 years or older who underwent elective surgical procedures under general anesthesia and received ventilation with the Baska mask or i-gel. Only randomized controlled trials comparing the two devices will be considered.

METHODS

MEDLINE, Embase, the Cochrane Library, Web of Science, ClinicalTrials.gov, OpenGrey, and ProQuest Dissertations and Theses will be searched to identify both published and unpublished studies. Titles and abstracts will be screened to identify potentially relevant papers. Retrieval of full-text studies, assessment of methodological quality, and data extraction will be performed independently by two reviewers. Data will be synthesized using statistical meta-analysis with heterogeneity of data being assessed using the standard chi-squared and I2 tests, if possible.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020168774.

Effectiveness of different supralottic airways during resuscitation manoeuvres. A systematic review

INTRODUCTION

Supraglottic airways, which are easily inserted and minimize interruptions in cardiopulmonary resuscitation manoeuvres, are now widely used in pre- and in-hospital emergencies. However, most studies in these devices do not specify whether they ensure good ventilation during CPR. This systematic review aims to determine whether there is evidence that supraglotic airways enable effective ventilation during resuscitation.

METHODS

The MEDLINE and COCHRANE databases were searched for studies published in English up to 30 November 2018. Eligible studies were all those that objectively evaluated tidal volume during resuscitation maneuvers in patients over 18 years of age using various supraglottic airways.

RESULTS

A total of 3734 articles were identified, of which 252 were duplicates. Only 1 objectively evaluated ventilation during resuscitation maneuvers and presented data relevant to this review. The study included 470 patients, 51 of which underwent spirometry. Only 4.48% of patients survived to hospital discharge; however, the correlation with ventilation effectiveness was not assessed.

CONCLUSION

There is no scientific evidence that supraglottic airways provide effective ventilation during resuscitation maneuvers. Evaluation by spirometry, chest impedance and ultrasound may help to determine the ventilatory efficacy of supraglottic airways during CPR, and clarify whether this factor contributes to the difficulties experienced in reversing cardiorespiratory arrest.

Recommendations for the evaluation and management of the anticipated and non-anticipated difficult airway of the Societat Catalana d'Anestesiologia, Reanimació i Terapèutica del Dolor, based on the adaptation of clinical practice guidelines and expert consensus

The Airway Division of the Catalan Society of Anaesthesiology, Intensive Care and Pain Management (SCARTD) presents its latest guidelines for the evaluation and management of the difficult airway. This update includes the technical advances and changes observed in clinical practice since publication of the first edition of the guidelines in 2008. The recommendations were defined by a consensus of experts from the 19 participating hospitals, and were adapted from 5 recently published international guidelines following an in-depth analysis and systematic comparison of their recommendations. The final document was sent to the members of SCARTD for evaluation, and was reviewed by 11 independent experts. The recommendations, therefore, are supported by the latest scientific evidence and endorsed by professionals in the field. This edition develops the definition of the difficult airway, including all airway management techniques, and places emphasis on evaluating and classifying the airway into 3 categories according to the anticipated degree of difficulty and additional safety considerations in order to plan the management strategy. Pre-management planning, in terms of preparing patients and resources and optimising communication and interaction between all professionals involved, plays a pivotal role in all the scenarios addressed. The guidelines reflect the increased presence of video laryngoscopes and second-generation devices in our setting, and promotes their routine use in intubation and their prompt use in cases of unanticipated difficult airway. They also address the increased use of ultrasound imaging as an aid to evaluation and decision-making. New scenarios have also been included, such as the risk of bronchoaspiration and difficult extubation Finally, the document outlines the training and continuing professional development programmes required to guarantee effective and safe implementation of the guidelines.

Choosing the best supraglottic airway for ophthalmic general anaesthesia: a manikin study

General anaesthesia is sometimes favoured over regional anaesthesia in ophthalmic surgery. The use of supraglottic airway (SGA) or laryngeal mask airway (LMA) as the primary airway device is increasing due to numerous advantages over tracheal intubation. Compared with 1st generation SGAs, 2nd generation SGAs have an added benefit of isolating the airway from the alimentary tract. However, the vertical profile of SGAs may encroach into the surgical field and hence interfere with surgery. We investigated the vertical projections of 1st generation SGAs (LMA Classic, Ambu AuraFlex) and commonly used 2nd generation SGAs in our institution (LMA ProSeal, LMA Supreme, LMA Protector, Ambu AuraGain and I-gel) in a manikin model. Each device was connected to a corrugated catheter mount or angled connector following insertion as per usual clinical practice in our institutions. Vertical projections of all devices were measured from the chin using a centimetre ruler. Securing of airway device to the chin with an adhesive tape was possible for the LMA Classic and Ambu AuraFlex with straight corrugated connector, whereas the stiffer 2nd generations SGAs required the addition of an angled connector or straight corrugated tubing to direct the airway tube caudally, away from the surgical field. The LMA ProSeal had the lowest vertical projection amongst the 2nd generation SGAs and may be the suitable choice for ophthalmic surgery. We also describe a novel technique of utilising a 1st generation SGA with placement of an orogastric tube, although with some reservations. This study has several limitations and transferability of our findings into clinical practice is questionable as the use of a manikin may not fully imitate the real condition of the patient. Our study is the first study comparing vertical projected height of different SGAs in manikin, but future studies should investigate the use of SGA in the clinical setting during ophthalmic surgery.

Anesthesia for the Morbidly Obese Patient

Obesity is considered a major comorbidity, and it is imperative for an anesthesiologist to put increased emphasis on preoperative evaluation and perioperative management. A multidisciplinary team approach is the key for a successful outcome. This article encompasses basic tenets like pathophysiology and pharmacology pertaining to obesity. The authors also talk about important aspects of anesthesia care starting from preoperative assessment and optimization, intraoperative challenges and care, to recovery and discharge of these patients.

Laryngeal Mask Airway Versus Tracheal Intubation for Laparoscopic Hernia Repair in Children: Analysis of Respiratory Complications

Purpose: The aim of this study was to compare the perioperative and postoperative respiratory complications between laryngeal mask (LM) airway and tracheal intubation (TI) in children undergoing percutaneous internal ring suturing (PIRS) for inguinal hernia. Patients and Methods: From October 2015 to February 2019, 135 pediatric patients (97 males and 38 females) with median age of 4 years, who underwent PIRS for inguinal hernia, were included in study. Patients were divided in two groups. In group I (n = 94) LM airway was used, and in group II (n = 41) TI was performed. Demographic data, surgical and anesthesia times, American Society of Anesthesiologists (ASA) classification, muscle relaxation, level of pneumoperitoneum, and complications of anesthesia were compared between the groups. Results: No significant differences among compared groups regarding age (P = .435), sex (P = .306), body mass index (P = .548), ASA classification (P = .506), level of pneumoperitoneum (P = .968), and duration of surgery (P = .968) were found. Duration of anesthesia was significantly shorter when LM was used compared to TI (25 minutes versus 36 minutes; P < .00001). During recovery from anesthesia, the incidences of desaturation (n = 1 versus n = 5; P = .003), laryngospasm (n = 2 versus n = 5; P = .015), and cough (n = 0 versus n = 4; P = .002) were significantly lower when LM airway was used for securing of the airway. Postoperative incidences of sore throat (P = .543), bronchospasm (P = .128), and aspiration (P = .128) did not differ between LM and TI. Conclusions: The use of LM in pediatric anesthesia results in a decrease in a number of common complications and significantly shortened patient anesthesia time. It is therefore a valuable device for the management of the pediatric airway for laparoscopic hernia repair in children.

Unilateral hypoglossal nerve palsy after the use of laryngeal mask airway (LMA) Protector

BACKGROUND

The laryngeal mask airway (LMAⓇ) ProtectorTM (Teleflex Medical Co., Ireland) is the latest innovation in the second generation of LMA devices. One distinguishing feature of this device is its integrated, color-coded cuff pressure indicator (Cuff PilotTM technology) which enables continuous cuff pressure monitoring and allows adjustments when necessary; this ensures patient safety due to better monitoring.

CASE

We report a case of postoperative unilateral hypoglossal nerve palsy after uncomplicated use of the LMA Protector. To the best of our knowledge, this could be the second reported case.

CONCLUSIONS

This case demonstrates that anesthetists need to routinely measure cuff pressure and that the Cuff PilotTM technology is not a panacea for potential cranial nerve injury after airway manipulation.

Comparison of early postoperative recovery between laryngeal mask airway and endotracheal tube in laparoscopic cholecystectomy: A randomized trial

BACKGROUND

Laryngeal mask airway (LMA) insertion provokes fewer stress responses than endotracheal intubation. This study aimed to evaluate the LMA Protector for assessing improvements in intraoperative hemodynamic stability and to reduce postoperative discomfort compared with endotracheal intubation in laparoscopic cholecystectomy.

METHODS

Fifty-six patients who underwent laparoscopic cholecystectomy while under sevoflurane-based general anesthesia were randomly allocated to airway management using LMA (LMA group) or endotracheal tube (ETT group). Heart rate, blood pressure, and peak airway pressure were recorded before and after carboperitoneum. Postoperative pain and analgesic requirements were assessed, in addition to nausea, hoarseness, dysphonia, and sore throat during the first 1 hour postoperatively and until postoperative day 1.

RESULTS

All patients underwent successful LMA or ETT placement within 2 attempts. There was no difference in highest mean (SD) peak airway pressure during carboperitoneum between the LMA and ETT groups (17.7 [2.8] mm Hg vs 19.1 [3.8] mm Hg, P = .159, respectively). The incidence of high systolic blood pressure and bradycardia was higher in the LMA group. The highest pain scores 1 hour postoperatively and on postoperative day 1 were lower in the LMA group than in the ETT group (3.9 [2.0] vs 5.4 [2.3], P = .017 and 5.6 [1.9] vs 6.7 [1.7], P = .042, respectively); requirements for analgesics were similar in the 2 groups. The incidence of nausea was lower in the LMA group than in the ETT group until postoperative day 1 (4/28 [14%] vs 12/28 [43%], P = .031, respectively).

CONCLUSION

The LMA Protector was an effective ventilator device associated with fewer intraoperative hemodynamic stress responses and improved the quality of early recovery after laparoscopic cholecystectomy.

Fiberoptic intubation of severely obese patients through supraglottic airway: A prospective, randomized trial of the Ambu® AuraGain™ laryngeal mask vs the i-gel™ airway

INTRODUCTION

Airway management in severely obese patients remains a challenging issue for anaesthetists and may lead to life-threatening situations. Supraglottic airway devices, such as the i-gel™ or the AuraGain™, were developed, with the possibility to ventilate the patient or use them as a conduit for endotracheal intubation.

METHODS

In our randomized prospective trial, we hypothesized a 10 seconds faster fiberoptic trans-device intubation time through the AuraGain™ laryngeal mask compared to the i-gel™ laryngeal mask in severely obese patients. We randomly assigned 44 patients to the AuraGain or i-gel group and measured trans-device intubation time after 5 minutes of successful ventilation through the device. Secondary parameters relating to the trans-device intubation success, oropharyngeal leak pressure, and parameters regarding insertion of the supraglottic airway devices were measured. Postoperative airway morbidity was determined 5 hours after surgery.

RESULTS

Mean (SD) intubation time was 55.7 (5.8) seconds for the AuraGain™ vs 54.1 (8.5) for i-gel™ mask (95% CI -2.7 to 5.9; P = 0.474), respectively, on a mean body mass index (BMI) of 39.4 kg/m² in the AuraGain™ group vs 38.9 kg/m² in i-gel™ group. No difference could be found in the other studied parameters.

CONCLUSIONS

Time for intubation through both supraglottic airway devices was similar. Attributed to fast possibility of securing the airway with both supraglottic airway devices, we believe that both, AuraGain™ and i-gel™, can be a good alternative in the airway management in obese patients.

Supraglottic airway devices in short gynecological procedures: A randomized, clinical study comparing the Baska® mask and I-Gel® device

Background

Supraglottic airway devices are used for anesthesia in elective surgical procedures circumventing the need for intubation. We investigated the efficacy and safety of Baska^® mask in comparison to an I-Gel^® device.

Methods

In this cross-sectional, observational study, we randomized 100 female patients (age 18-45 years, American Society of Anaesthesiologists grade I or II) undergoing elective short gynecological procedures into two groups, to receive ventilation with either Baska mask^® (group 1, n = 50) or an I-Gel^® device (group 2, n = 50). We excluded patients with obesity, short neck, and known systemic and upper airway disorders. The primary outcome was the oropharyngeal airway seal pressure, and the secondary outcomes were the ease of insertion and the complication rate. The results were analyzed using Mann-Whitney U-test and Fisher's exact test, and correlation analysis was done by Spearman's correlation test.

Results

A total of 56 patients underwent dilatation and curettage, whereas the remaining had hysteroscopy in the study. The airway seal pressure achieved was higher with Baska^® mask than I-Gel^® device (35.8 ± 10.3 and 26.9 ± 7.5 of cm H₂O, respectively; P < 0.0001). The ease of insertion (P < 0.0001) was better in group 1 and the complication rates were similar in both the groups (P > 0.05).

Conclusion

Baska^® mask offers a superior airway seal pressure with minimum complications in comparison to an I-Gel^® device. Further studies with a large number of patients in different surgical settings are required to confirm our findings.

Randomized comparison of the Baska FESS mask and the LMA Supreme in different head and neck positions

BACKGROUND

The Baska functional endoscopic sinus surgery (FESS) mask is a new supraglottic airway designed for head and neck procedures. This prospective, randomized controlled trial compared the oropharyngeal leak pressure (OLP) of the Baska FESS mask with the laryngeal mask airway (LMA) Supreme in different head and neck positions.

METHODS

One hundred patients undergoing elective surgery were recruited. OLP was compared in supine position, 45° lateral rotation, 45° neck extension, and 30° neck flexion. Glottic view, insertion time, ease of insertion, number of attempts, ease and time of insertion of gastric tube, and complications were also compared.

RESULTS

The OLP of the Baska FESS was higher than the LMA Supreme in all head and neck positions studied (p < 0.001). Glottic views were better in the Baska FESS in supine and lateral rotation. LMA Supreme was easier (p = 0.046) and faster (p < 0.001) to insert. First attempt insertion success rates were 91.8% for Baska FESS and 98% for LMA Supreme. Gastric drain was easier and faster to insert (p < 0.001) in the LMA Supreme.

CONCLUSIONS

The Baska FESS provides a superior airway seal with higher mean OLP than the LMA Supreme in all head and neck positions studied. However, LMA Supreme was superior in terms of ease and speed of insertion.

Short-lasting pediatric laparoscopic surgery: Are muscle relaxants necessary? Endotracheal intubation vs. laryngeal mask airway

PURPOSE

Technical advances have led to lower insufflation pressures and shorter anesthesia times for children undergoing laparoscopic procedures. In this study we compared the use of endotracheal tube (ETT) and laryngeal mask airway (LMA) with or without muscle relaxant (MR) in children undergoing laparoscopic repair for inguinal hernia.

METHODS

Children undergoing laparoscopic inguinal hernia repair were randomized into four groups which underwent procedure with either ETT+MR (group 1), ETT without MR (group 2), LMA with subparalytic dose of MR (group 3) or LMA without MR (group 4). Surgical, anesthesia and recovery times, intragastric pressures and peak airway pressures during insufflation were compared.

RESULTS

After exclusion criteria and discontinued interventions, groups 1 and 3 contained 20, groups 2 and 4 contained 19 patients each. Surgical times were similar between groups. Anesthesia times were statistically significantly different between groups with shortest time in group 4 and longest time in group 1. Recovery time was statistically significantly longer in group 1 when compared to other groups. There was no difference between basal intragastric pressure, average intragastric pressure during insufflation, peak airway pressure, and average peak airway pressure during insufflation of groups.

CONCLUSION

Use of muscle relaxants in short-lasting laparoscopic procedures in children is not absolutely necessary and LMA with subparalytic dose of muscle relaxant or with no muscle relaxant is a safe alternative.

TYPE OF STUDY

Treatment study.

LEVEL OF EVIDENCE

Level II.

Laryngeal mask airway protector™: Advanced uses for laparoscopic cholecystectomies

The laryngeal mask airway (LMA) Protector™ is a second-generation perilaryngeal sealer type supraglottic airway device recently introduced into clinical practice. We describe our initial experiences with the use of the LMA Protector™ in three patients undergoing laparoscopic cholecystectomies. In all patients, we found the LMA Protector™ to have acceptable placements on the first attempt, adequate oropharyngeal leak pressures and ventilation adequacy.