Supraglottic airways in difficult airway management: successes, failures, use and misuse

How does head position affect laryngeal vision with a video laryngeal mask airway?

Background

The Laryngeal Mask Airway Vision Mask (LMA VM) is a supraglottic airway device (SAD) with a vision guidance system. The ideal head and neck position for direct laryngoscopy is known, but the ideal position for placing a LMA is not. The objective of this study is to evaluate and compare the optimal position for placement of a video laryngeal mask airway.

Methods

This prospective, observational, transversal, and analytical study was performed in 72 consecutive patients. In the same patient, laryngeal vision was first assessed with the head and neck in the sniffing position and then with the head in the neutral position. Procedures were performed by the same investigator. The assessment of the laryngeal view was performed using two classifications: Cormack-Lehane classification and Brimacombe classification. The placement of the device was considered adequate when the Cormack-Lehane rating was between 1 and 2 and the Brimacombe rating between 2 and 4.

Results

In this study, 72 patients participated. In the assessment of the glottis using the Cormack-Lehane classification for fibre-optic view, laryngeal visibility was adequate in 64 (88.89%) patients in the neutral position and in 65 (90, 28%) patients in the sniffing position (p > 0.05). In the fibre-optic view of the glottis, evaluated using the Brimacombe classification, laryngeal visibility was adequate in 68 (93%) patients in the neutral position and in 69 (95%) patients in the sniffing position (p > 0.05). There was no statistically significant difference in the rate of success between the sniffing position (70 patients, 97.22% success rate) and the neutral position (67 patients, 93.06% success rate) during the first insertion attempt. Two patients required a second attempt in the sniffing position, while five patients required a second attempt in the neutral position.

Conclusion

An adequate sniffing position did not result in a better glottic view than the neutral position. Additional manoeuvres were equal in both positions. The head-neck position does not influence on the placement of a third-generation SAD.

A new video laryngoscope combined with flexible laryngeal mask insertion: A prospective randomized study

BACKGROUND

The video laryngoscope (VLS) has been proven to be an effective insertion device for airway management. However, no laryngoscope has been specifically designed for the placement of the laryngeal mask airway (LMA). We improved the current VLS and developed a novel VLS method. This study aimed to evaluate the clinical efficacy of an improved VLS for inserting a flexible laryngeal mask airway (F-LMA) compared with the standard blind method.

METHODS

One hundred and fifty-seven patients who underwent F-LMA insertion under general anesthesia were randomly assigned to either the standard blind insertion technique (group B) or VLS -assisted insertion (group VL). First attempt success rates were recorded. Secondary outcomes included oropharyngeal leakage pressure (OLP), fiberoptic view, insertion time, position adjustment, reinsertion rate, and postoperative airway morbidity.

RESULTS

The first-attempt success rate was higher in group VL than that in group B (99% vs. 86%; p = 0.002). The OLP was significantly higher in the VLS-guided technique (26.4 ± 5.1 vs 23.8 ± 4.4 cmH2O, p = 0.002). The fiberoptic view was significantly better in the group VL (p < 0.001) and required less readjustment and reinsertion to establish an effective airway (p < 0.001). The insertion time was shorter in the group B than that in group VL (33.9 vs 41.3 s, p < 0.001). Hemodynamic stress responses and postoperative airway complications did not differ between the two groups.

CONCLUSIONS

The new VLS-guided insertion technology has a high success rate, achieves greater OLP, and provides an ideal anatomical position with minimal adjustment, without increasing the risk of hemodynamic stress or adverse events.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (registration number: ChiCTR2300075866; https://www.chictr.org.cn).

Innovative (and Safe) Techniques With Supraglottic Airways

ABSTRACT

Supraglottic airways have been utilized as an alternative to facemask ventilation and endotracheal intubation and thus have been essential to airway management since their introduction in the late 1980s. This chapter describes basic considerations in their use and an update on current clinical practice, with an emphasis on safe management. The devices have evolved to meet today's clinical airway challenges, and they provide benefits for patients and practitioners.

To compare the efficacy of the between-the-fingers grip with the conventional pen-holding grip to hold an endotracheal tube for orotracheal intubation: A randomised controlled trial

Background and Aims

Correctly holding the endotracheal tube (ETT) is essential for successful tracheal intubation. The study's primary objective was to compare the between-the-fingers grip with the conventional pen-holding grip regarding the number of attempts required for orotracheal intubation and usage of external aids.

Methods

Three hundred patients undergoing elective surgeries under general anaesthesia were randomised according to the method to hold the ETT to Group C (conventional grip) and Group M (modified, between-the-fingers grip) during oro-tracheal intubation. A designated anaesthetist blinded to the groups performed laryngoscopy in all the patients, and difficult Cormack-Lehane grade 3b and 4 (n = 24) were excluded. Then, the group was revealed to the anaesthetist, and intubation was done accordingly; the number of attempts, use of backward upward rightward pressure (BURP), and time taken were noted. The sample size was estimated using the software G*Power version 3.1.9.2. Statistical Package for Social Sciences, version 23 (SPSS-23, IBM, Chicago, USA) was used for data analysis.

Results

Single-attempt intubation was comparable between the groups (99.3% versus 97.2%, P = 0.197). In contrast, the external assistance as BURP (0.75% versus 6.99%, P = 0.009) and the time taken for intubation (P = 0.008) were reduced in group M significantly.

Conclusion

The between-the-fingers grip seems as effective as the standard grip to hold the ETT during intubation. However, it proved to be better as it can reduce the requirement for external assistance in BURP.

Spanish Society of Anesthesiology, Reanimation and Pain Therapy (SEDAR), Spanish Society of Emergency and Emergency Medicine (SEMES) and Spanish Society of Otolaryngology, Head and Neck Surgery (SEORL-CCC) Guideline for difficult airway management. Part II

The Airway Management section of the Spanish Society of Anesthesiology, Resuscitation, and Pain Therapy (SEDAR), the Spanish Society of Emergency Medicine (SEMES), and the Spanish Society of Otorhinolaryngology and Head and Neck Surgery (SEORL-CCC) present the Guide for the comprehensive management of difficult airway in adult patients. Its principles are focused on the human factors, cognitive processes for decision-making in critical situations, and optimization in the progression of strategies application to preserve adequate alveolar oxygenation in order to enhance safety and the quality of care. The document provides evidence-based recommendations, theoretical-educational tools, and implementation tools, mainly cognitive aids, applicable to airway management in the fields of anesthesiology, critical care, emergencies, and prehospital medicine. For this purpose, an extensive literature search was conducted following PRISMA-R guidelines and was analyzed using the GRADE methodology. Recommendations were formulated according to the GRADE methodology. Recommendations for sections with low-quality evidence were based on expert opinion through consensus reached via a Delphi questionnaire.

Supraglottic Airway Devices: Present State and Outlook for 2050

Correct placement of supraglottic airway devices (SGDs) is crucial for patient safety and of prime concern of anesthesiologists who want to provide effective and efficient airway management to their patients undergoing surgery or procedures requiring anesthesia care. In the majority of cases, blind insertion of SGDs results in less-than-optimal anatomical and functional positioning of the airway devices. Malpositioning can cause clinical malfunction and result in interference with gas exchange, loss-of-airway, gastric inflation, and aspiration of gastric contents. A close match is needed between the shape and profile of SGDs and the laryngeal inlet. An adequate first seal (with the respiratory tract) and a good fit at the second seal of the distal cuff and the gastrointestinal tract are most desirable. Vision-guided insertion techniques are ideal and should be the way forward. This article recommends the use of third-generation vision-incorporated-video SGDs, which allow for direct visualization of the insertion process, corrective maneuvers, and, when necessary, insertion of a nasogastric tube (NGT) and/or endotracheal tube (ETT) intubation. A videoscope embedded within the SGD allows a visual check of the glottis opening and position of the epiglottis. This design affords the benefit of confirming and/or correcting a SGD's position in the midline and rotation in the sagittal plane. The first clinically available video laryngeal mask airways (VLMAs) and multiple prototypes are being tested and used in anesthesia. Existing VLMAs are still not perfect, and further improvements are recommended. Additional modifications in multicamera technology, to obtain a panoramic view of the SGD sitting correctly in the hypopharynx and to prove that correct sizes have been used, are in the process of production. Ultimately, any device inserted orally-SGD, ETT, NGT, temperature probe, transesophageal scope, neural integrity monitor (NIM) tubes-could benefit from correct vision-guided positioning. VLMAs also allow for automatic recording, which can be documented in clinical records of patients, and could be valuable during teaching and research, with potential value in case of legal defence (with an airway incident). If difficulties occur with the airway, documentation in the patient's file may help future anesthesiologists to better understand the real-time problems. Both manufacturers and designers of SGDs may learn from optimally positioned SGDs to improve the design of these airway devices.

In-hospital care of children with COVID-19

Children have been reported to be less affected and to have milder severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection than adults during the coronavirus disease 2019 (COVID-19) pandemic. However, children, and particularly those with underlying disorders, are still likely to develop critical illnesses. In the case of SARS-CoV-2 infection, most previous studies have focused on adult patients. To aid in the knowledge of in-hospital care of children with COVID-19, this study presents an expert review of the literature, including the management of respiratory distress or failure, extracorporeal membrane oxygenation (ECMO), multisystem inflammatory syndrome in children (MIS-C), hemodynamic and other organ support, pharmaceutical therapies (anti-viral drugs, anti-inflammatory or antithrombotic therapies) and management of cardiopulmonary arrest.

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.

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.

Laryngeal mask general anaesthesia versus spinal anaesthesia for promoting early recovery of cervical conisation: A randomised, controlled clinical study

Background

Although both spinal and general anaesthesia provides good anaesthesia for cervical conization, spinal anaesthesia delays the return of lower limb movements and urinary function, whereas general anaesthesia requires the patient to be unconscious. It is unclear which anaesthetic technique is more conducive to early postoperative recovery in patients undergoing cervical conization.

Patients and methods

140 patients undergoing cervical conization underwent either laryngeal mask general anaesthesia (LMA, n = 70) or spinal anaesthesia (SA, n = 70). In the LMA group, an i-gel mask was used for airway management. In the SA group, spinal anaesthesia was received with 0.75% ropivacaine (15 mg) in the L3-4 interval. The quality of recovery score (QoR-15) was the primary endpoint of the study. Secondary endpoints included incidence of adverse 24-h analgesia (NRS>3); return of lower limb activity; first bed activity and feeding; and the number of catheters removed at 6, 12 and 24 h postoperatively.

Result

The LMA group significantly improved QoR-15 scores (136.62 ± 11.02 vs 119.97 ± 12.75; P < 0.001); and reduced the incidence of poor analgesia (NRS >3) within 24 h postoperatively (20% vs 42.8%, P = 0.006); reduced time in bed (15.62 ± 3.83 h vs 18.27 ± 5.57 vs, P = 0.001); improved patient satisfaction (86% vs 27%; P < 0.001); and catheters removal within 24 h (70/70 vs 42/70, P < 0.001).

Conclusion

LMA general anaesthesia can facilitate early postoperative recovery in patients undergoing cervical conization compared with conventional spinal anaesthesia.

Trial registration

Chinese Clinical Trial Registry (ID: ChiCTR1800019384), http://www.chictr.org.cn/listbycreater.aspx (08/11/2018).

New technologies in airway management: A review

The evolution of medical knowledge and technological growth have contributed to the development of different techniques and devices for airway management. These appear to play a role in optimizing the number of attempts and overall success, ultimately reducing the negative consequences of airway manipulation. In this literature review, we highlight the recent evidence regarding new technologies applied to airway management. Before intubation, every patient should have an individualized structured airway management plan. Technology can help with both airway evaluation and tracheal intubation. Point-of-care cervical ultrasound and artificial intelligence models with automated facial analysis have been used to predict difficult airways. Various devices can be used in airway management. This includes a robotic video endoscope that guides intubation based on real image recognition, a laryngeal mask with a non-inflatable cuff that tries to reduce local complications, video laryngeal masks that are able to confirm the correct position and facilitate intubation, Viescope™, a videolaryngoscope developed for combat medicine with a unique circular blade, a system that uses cervical transillumination for glottis identification in difficult airways and Vivasight SL™ tracheal tube, which has a high-resolution camera at its tip guaranteeing visual assurance of tube position as well as guiding bronchial blocker position. To conclude, we detailed the challenges in airway management outside the operating room as well as described suction-assisted laryngoscopy and airway decontamination technique for contaminated airways. Further research in the clinical setting is recommended to better support the use of these technologies.

Comparison of SaCoVLM™ video laryngeal mask-guided intubation and i-gel combined with flexible bronchoscopy-guided intubation in airway management during general anesthesia: a non-inferiority study

BACKGROUND

When a difficult airway is unanticipatedly encountered and the initial laryngoscopic intubation fails, a supraglottic airway device (SAD) may be placed to aid ventilation and oxygenation, and act as a conduit for intubation. SaCoVLM™, as new SAD, can offer a direct vision to guide intubation. However, no study has evaluated the performance of SaCoVLM™ video laryngeal mask (VLM) intubation and i-gel combined with flexible bronchoscopy (FB)-guided intubation in airway management during general anesthesia.

METHODS

A total of 120 adult patients were randomly allocated into the SaCoVLM™ group (Group S) and i-gel group (Group I). After induction of general anesthesia, guided tracheal intubation under direct vision of the SaCoVLM™ was conducted in Group S, while Group I received FB-guided tracheal intubation using the i-gel. The success rate of SAD placement, first-pass success rate of guided tracheal tube placement, and total success rate in both groups were recorded. The time for SAD placement, time for guided tracheal intubation, total intubation time (time for SAD placement and intubation), glottic exposure grading and postoperative intubation complications (i.e., dysphagia, hoarseness, pharyngalgia, etc.) of both groups were also compared.

RESULTS

The first-time success rate of SAD placement was 98% in two groups. The first-pass success rate of guided endotracheal intubation was 92% in Group S and 93% in Group I (P = 0.74 > 0.05). The total intubation time was 30.8(± 9.7) s and 57.4(± 16.6) s (95% CI = -31.5 to -21.7) in Group S and Group I, respectively (P < 0.01). The total complication rate was 8% in Group S and 22% in Group I (P < 0.05). The laryngeal inlet could be observed in the S group through the visual system of SaCoVLM™. No dysphagia or hoarseness was reported.

CONCLUSION

SaCoVLM™ can reveal the position of laryngeal inlet, thus providing direct vision for tracheal intubation. SaCoVLM™ -guided intubation is faster, and does not rely on FB, compared to i-gel combined with FB-guided intubation. Besides, SaCoVLM™ has a lower post-intubation complication rate.

TRIAL REGISTRATION

Chinese Clinical Trials Registry (ChiCTR2100043443); Date of registration: 18/02/2021.

General anesthesia for cesarean section: are we doing it well?

Korea has a higher rate of cesarean sections under general anesthesia than in other countries. Neuraxial anesthesia is the gold standard for a cesarean section, but there are some cases in which general anesthesia is inevitable. Therefore, obstetric anesthesiologists should be familiar in performing general anesthesia for cesarean section. Rapid-sequence induction and intubation with cricoid pressure using thiopental-succinylcholine have been the standard for cesarean section under general anesthesia for a long time. Recently, with the introduction of new drugs (propofol, rocuronium, and sugammadex) and equipments (videolaryngoscopy and supraglottic airways), anesthesia methods have also gradually changed. Pursuing the safety of obstetric patients and anesthesiologists at the same time, this review will help update the knowledge or training in performing general anesthesia for cesarean section.

Updated guideline on equipment to manage difficult airways: Australian and New Zealand College of Anaesthetists

The Australian and New Zealand College of Anaesthetists (ANZCA) recently reviewed and updated the guideline on equipment to manage a difficult airway. An ANZCA-established document development group, which included representatives from the Australasian College for Emergency Medicine and the College of Intensive Care Medicine of Australia and New Zealand, performed the review, which is based on expert consensus, an extensive literature review, and bi-nationwide consultation. The guideline (PG56(A) 2021, https://www.anzca.edu.au/getattachment/02fe1a4c-14f0-4ad1-8337-c281d26bfa17/PS56-Guideline-on-equipment-to-manage-difficult-airways) is accompanied by a detailed background paper (PG56(A)BP 2021, https://www.anzca.edu.au/getattachment/9ef4cd97-2f02-47fe-a63a-9f74fa7c68ac/PG56(A)BP-Guideline-on-equipment-to-manage-difficult-airways-Background-Paper), from which the current recommendations are reproduced on behalf of, and with the permission of, ANZCA. The updated 2021 guideline replaces the 2012 version and aims to provide an updated, objective, informed, transparent, and evidence-based review of equipment to manage difficult airways.

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.

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.

Head elevation and laryngeal mask airway Supreme insertion: A randomized controlled trial

BACKGROUND

A laryngeal mask airway (LMA) is usually inserted by conventional 7 cm head elevation. However, little is known about the association of head elevation degree and LMA insertion. We hypothesized that 14 cm head elevation would increase the first attempt success rate of LMA Supreme insertion compared with conventional 7 cm head elevation in patients undergoing transurethral resection of bladder tumour.

METHODS

Patients were randomly allocated to the high group (n = 55, 14 cm head elevation) or the control group (n = 55, conventional 7 cm head elevation). The primary outcome was the first attempt success rate of LMA Supreme insertion.

RESULTS

The first attempt success rate was significantly higher in the high group than in the control group (53 [96.4%] vs 40 [72.7%], P = .001, relative risk = 1.30, 95% confidence interval [CI] = 1.12-1.57, absolute risk reduction = 23.7%). Fibreoptic bronchoscope grade 4 (ie optimal position of the LMA) was significantly higher in the high group (35 [64.8%] vs 18 [36.7%], P = .004, relative risk = 1.76, 95% CI = 1.16-2.68, absolute risk reduction = 30.9%).

CONCLUSIONS

Head elevation of 14 cm height increased the first attempt success rate of LMA Supreme insertion and fibreoptic bronchoscopic grade in patients undergoing transurethral resection of bladder tumour. High head elevation can be an effective option for successful LMA Supreme insertion. Trial Registry Number: Clinicaltrials.gov (NCT04229862).

Comparison of endotracheal intubation, laryngeal mask airway, and I-gel in children undergoing strabismus surgery

Background

Insertion of the advanced airway during induction of general anesthesia can cause undesirable sympathetic stimulation such as increased intraocular pressure (IOP) and hemodynamic parameters. In this study, we compared insertion of three different advanced airway devices; endotracheal tube (ETT), laryngeal mask airway (LMA) and I-gel in terms of IOP, hemodynamic changes and postoperative nausea and vomiting (PONV) following induction of general anesthesia with propofol and remifentanil in children undergoing strabismus surgery.

Materials and Methods

A total of 90 children (5.68 ± 1.49 years old) were randomly assigned to one of the three groups, ETT, LMA, or I-gel insertion as advanced airway devices IOP and also hemodynamic variables were measured before (T0 and T1) and immediately after (T2) the insertion of these airway devices, although 2 min (T3) and 5 min (T4) after it. PONV was assessed about 2 h after the completion of surgery in the recovery room.

Results

The mean arterial pressure (MAP), IOP, and systolic and diastolic blood pressures were significantly different between the three groups immediately (T2), 2 min (T3), and 5 min (T4) after the insertion of airway devices. The heart rate (HR) was significantly different between the three groups in all measurement times except of T0. Within-group comparisons showed that the three groups had significant changes in MAP, IOP, HR, systolic and diastolic pressure before and after airway insertion (T1 and T2). The trend in the LMA and ETT groups was descending-ascending-descending, whereas in the I-gel group, it was quite descending. There was no significant difference among the three groups in terms of PONV.

Conclusion

As a result, our study showed that, compared with LMA and ETT, the I-gel had less impact on undesirable stress responses and seems to be superior to LMA and ETT in children undergoing strabismus surgery.

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.

The distance between the glottis and the cuff of a tracheal tube placed through three supraglottic airway devices in children: A randomised controlled trial

BACKGROUND

After tracheal tube insertion via various types of supraglottic airway devices, the distance from the tube cuff to the vocal cords has not been evaluated in children.

OBJECTIVES

The aim of this study was to evaluate the position of a tracheal tube cuff relative to the glottis in children when one of three supraglottic airway devices (I-gel, AuraGain and air-Q laryngeal airway) are used as intubation conduits.

DESIGN

A randomised controlled trial.

SETTING

Tertiary children's hospital.

PATIENTS

Children aged less than 7 years.

INTERVENTION

In vivo fibre-optic assessment and in vitro measurement.

MAIN OUTCOME MEASURES

The main outcome was the safety margin: the distance between the ventilation outlet of the supraglottic airway device and the beginning of the proximal cuff minus that from the ventilation outlet to the glottis. The maximum inner diameter of the cuffed tracheal tube that could be inserted, the fibre-optic view score and the oropharyngeal leak pressure were also evaluated.

RESULTS

The three devices exhibited significant differences in the distance from the ventilation outlet to the glottis (mean ± SD): I-gel 3.6 ± 0.6 cm, AuraGain 3.8 ± 0.7 cm, air-Q 2.8 ± 1.0 cm (P < 0.001). The safety margin was greatest with the air-Q and narrowest with the I-gel: I gel 1.9 ± 1.1 cm, AuraGain 4.4 ± 0.7 cm and air-Q 7.9 ± 1.1 cm. Using the AuraGain and air-Q, the cuffs of the tracheal tubes were predicted to be located below the glottis with one-size and two-size smaller tracheal tubes in all patients. However, using I-gel, the cuffs would be below the glottis in 69% (95% CI 49.6 to 84.5) and 29% (95% CI 14.0 to 48.4) of the patients with a one-size and two-size smaller tube, respectively.

CONCLUSION

The AuraGain and air-Q are well tolerated intubating conduits. The possibility of vocal cord damage is higher when the I-gel is used.

TRIAL REGISTRATION

www.clinicaltrials.gov (number: NCT03156166).

Availability and organization of difficult airway equipment in Swedish hospitals: A national survey of anaesthesiologists

BACKGROUND

Airway complications account for almost one third of anaesthesia-related brain damage and death. Immediate access to equipment enabling rescue airway strategies is crucial for successful management of unanticipated difficult airway situations.

METHODS

We conducted a nationwide survey of Swedish anaesthesiologists to analyse availability and organization of difficult airway trolleys (DATs), and multiple factors pertaining to difficult airway management, to highlight areas of potential improvement.

RESULTS

Six hundred and thirty-nine anaesthesiologists completed the 14-item survey. Whereas DATs were almost ubiquitous (95%) in main operating departments of hospitals, prevalence was low in remote anaesthetizing locations (20.3%) and electroconvulsive therapy units (26.6%). Approximately 60% of emergency departments had a DAT. Immediate (within 60 seconds) access to videolaryngoscopes in all units where general anaesthesia is conducted was reported by 56.8%. Almost half of anaesthesiologists reported that all DATs at their workplace were standardized. Forty-six per cent reported that the DATs were organized according to a difficult airway algorithm; almost 90% believe that such an organization can impact the outcome of a difficult airway situation positively. Only 36.2% of DATs contained second-generation supraglottic airway devices exclusively. Most Swedish anaesthesiologists use the Swedish Society of Anaesthesiology and Intensive care Medicine difficult airway algorithm, but almost one fifth prefer the Difficult Airway Society algorithm. Less than half of respondents underwent formal difficult airway training annually.

CONCLUSION

Our results motivate efforts to (a) increase availability of DATs in remote anaesthetizing locations, (b) increasingly standardize DATs and organize DATs according to airway algorithms, and (c) increase the frequency of difficult airway training.

Awake supraglottic airway guided flexible bronchoscopic intubation in patients with anticipated difficult airways: a case series and narrative review

Awake intubation is indicated in difficult airways if attempts at securing the airway after induction of general anesthesia may lead to harm due to potential difficulties or failure in those attempts. Conventional awake flexible bronchoscopic intubation is performed via the nasal, or less commonly, oral route. Awake oral flexible bronchoscopic intubation (FBI) via a supraglottic airway device (SAD) is a less common technique; we refer to this as ‘supraglottic airway guided’ FBI (SAGFBI). We describe ten cases with anticipated difficult airways in which awake SAGFBI was performed. After sedation and adequate airway topicalization, an Ambu Auragain^TM SAD was inserted. A flexible bronchoscope, preloaded with a tracheal tube, was then inserted through the SAD. Finally, the tracheal tube was railroaded over the bronchoscope, through the SAD and into the trachea. The bronchoscope and the SAD were carefully removed, whilst keeping the tracheal tube in-situ. The technique was successful and well tolerated by all patients, and associated complications were rare. It also offered the advantages of performing an ‘awake test insertion’ of the SAD, an ‘awake look’ at the periglottic region, and an ‘awake test ventilation.’ In certain patients, awake SAGFBI offers advantages over conventional awake FBI or awake videolaryngoscopy. More research is required to evaluate its success and failure rates, and identify associated complications. Its place in difficult airway algorithms may then be further established.

[Preclinical emergency anesthesia : A current state analysis from 2015-2017]

BACKGROUND AND OBJECTIVE

Due to multiple factors the performance of preclinical emergency anesthesia is fraught with risks even for experienced emergency physicians. In order to support emergency physicians in monitoring and management of anesthesia, the German practice management guidelines for preclinical emergency anesthesia in adults were published in 2015; however, current data on adherence to the guidelines are not available.

MATERIAL AND METHODS

In a retrospective register analysis of preclinical anesthesia from 2015-2017 in Baden-Württemberg, the recorded anesthetic agents, monitoring, airway management and medical disciplines of emergency physicians were analyzed. The anesthetic agents utilized were compared to the emergency scenarios in the guidelines (e.g. cardiac patients, patients with acute respiratory insufficiency or acute neurological disorder and trauma patients).

RESULTS

Midazolam and propofol were predominantly used in the 12,605 cases of preclinical emergency anesthesia evaluated. The adherence to the guidelines was 35% for cardiac patients, 51% for patients with acute respiratory insufficiency or 52% for acute neurological disorders and 79% for trauma patients. Securing the airway was carried out in 88.5 % with endotracheal intubation (capnography 79%). Discipline-related differences occurred in airway management for the devices used, capnography, muscle relaxation and the frequency of the subjectively difficult airway. A higher adherence for trauma patients and patients with acute neurological disorders was found for emergency physicians who were anesthesiologists compared to non-anesthesiologists.

CONCLUSION

The study of the current state of preclinical emergency anesthesia in Germany showed a deficient implementation of the pharmacological recommendations for action except for trauma patients. Reasons for divergence could arise due to different availability of rescue equipment, training concepts or discipline of emergency physicians. Suitable education and training could improve the quality of prehospital anesthesia in Germany.

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.

The Difficult Airway Trolley: A Narrative Review and Practical Guide

Death and severe morbidity attributable to anesthesia are commonly associated with failed difficult airway management. When an airway emergency develops, immediate access to difficult airway equipment is critical for implementation of rescue strategies. Previously, national expert consensus guidelines have provided only limited guidance for the design and setup of a difficult airway trolley. The overarching aim of the current work was to create a dedicated difficult airway trolley (for patients>12 years old) for use in anesthesia theatres, intensive care units, and emergency departments. A systematic literature search was performed, using the PubMed, Embase, and Google Scholar search engines. Based on evidence presented in 11 national or international guidelines, and peer-reviewed journals, we present and outline a difficult airway trolley organized to accommodate sequential progression through a four-step difficult airway algorithm. The contents of the top four drawers correspond to specific steps in the airway algorithm (A = intubation, B = oxygenation via a supraglottic airway device, C = facemask ventilation, and D = emergency invasive airway access). Additionally, specialized airway equipment may be included in the fifth drawer of the proposed difficult airway trolley, thus enabling widespread use. A logically designed, guideline-based difficult airway trolley is a vital resource for any clinician involved in airway management and may aid the adherence to difficult airway algorithms during evolving airway emergencies. Future research examining the availability of rescue airway devices in various clinical settings, and simulation studies comparing different types of difficult airway trolleys, are encouraged.

[Performance of prehospital emergency anesthesia and airway management : An online survey]

BACKGROUND

The goal of rapid sequence induction (RSI) in cases of emergency situations is to secure the airway as quickly as possible to prevent pulmonary aspiration of gastric contents; however, the technique itself is not standardized. For example, the choice of drugs, application of cricoid pressure and the patient position remain controversial. A survey of emergency medical services (EMS) physicians throughout Germany was carried out to assess the different RSI techniques used and with respect to complying with the national guidelines for emergency airway management anesthesia and local standard operating procedures (SOP).

MATERIAL AND METHODS

Between 1 April 2017 and 31 May 2017, EMS medical directors in Germany were contacted and asked to distribute a 28-question online questionnaire to local EMS physicians. Of the questions 26 were multiple choice and 2 with plain text. After 6 weeks an e‑mail reminder was sent. In addition, the survey was distributed via social media to EMS physicians.

RESULTS

In total the survey was opened 2314 times and 1074 completed responses were received (completion rate 46%). Most of the participants were male (78%) and anesthesiologists (70%) and only one quarter had a local SOP for RSI. The most frequently used muscle relaxant was succinylcholine (62%) and over half of the participants reported using cricoid pressure (57%). There was a distinction between the specialist disciplines in the selection of drugs. Propofol was used most by anesthesiologists, while the others still used etomidate on a larger scale. Nearly 100% could fall back on supraglottic devices (one third laryngeal mask, two thirds laryngeal tube) but only 32.8% with the recommended esophageal drainage. A video laryngoscope was available to 51% of all EMS physicians surveyed.

CONCLUSION

The results of the survey demonstrate heterogeneity in RSI techniques used by EMS physicians in Germany. Medical equipment and safe care practices, such as labeling of syringes varied considerably between different service areas. The recommendations of the S1 national guidelines on emergency airway management and anesthesia should be adhered to together with the implementation of local SOPs.

Performance and skill retention of five supraglottic airway devices for the pediatric difficult airway in a manikin

Supraglottic airway devices (SADs) have been introduced to assist medical professionals in emergency situations with limited experience in securing airways via conventional endotracheal intubation (ETI). Literature on the use of SADs for securing an airway during pediatric critical settings is scarce, and there is a lack of studies comparing different SADs to each other and to conventional ETI. We conducted a study comparing five different SADs to ETI with regard to success rate, time to first ventilation, and personal rating in a pediatric manikin under simulated physiologic and pathologic airway conditions in 41 pediatricians of varying clinical experience and training. Only the AirQ, AuraG, and laryngeal tube (LT) were inserted within 30 s correctly by all participants under physiologic conditions. In tongue edema (TE), AirQ and LT had the highest success rate. In limited mobility of the cervical spine (CS), AirQ, AuraG, and LT again all were inserted within 30 s. In a multivariate analysis, factors influencing the success were experience with the respective device and level of medical education. Under TE conditions, there were significantly longer insertion times for the ETI, laryngeal mask airway (LMA), and EzT. Under CS conditions, there were significantly longer insertion times for the ETI, LMA, LT, and EzT. A multivariate analysis showed experience with the respective device to be the only factor of influence on time to first ventilation.

CONCLUSION

LT, AuraG, and AirQ were superior in providing fast and effective ventilation during simulated difficult airway situations in pediatricians. What is Known: • Supraglottic airway devices have been introduced for medical professionals who lack experience for managing difficult airway situations. • A variety of these devices have been developed so far, but not compared to each other yet. What is New: • We compared five different supraglottic airway devices with regard to success rate, time to first ventilation, and personal rating in a pediatric manikin under simulated physiologic and pathologic airway conditions. • Laryngeal tube, AuraG, and AirQ were superior in providing fast and effective ventilation during simulated difficult airway situations in pediatricians with varying clinical experience.

Streamlined Liner of the Pharynx Airway: Randomised Comparison of Size Selection Strategies with Regard to Patient Height versus Thyroid Cartilage Width

Introduction

Streamlined Liner of the Pharynx Airway (SLIPA) is a disposable supraglottic airway. There are two strategies to select the size of SLIPA: by height and width of thyroid cartilage. This study compared the utility of the two strategies in selecting the optimal size.

Methods

One hundred forty-two patients were randomly divided into two groups with size selection by height (H) and the maximal width of the thyroid cartilage (T). The SLIPA size was selected by height in group H, and by the width of thyroid cartilage in group T. After inserting SLIPA, the investigator made note of the oropharyngeal leakage pressure (OLP) and the degree of insertion difficulty. We set the OLP as a primary outcome. In cases of an OLP <15 cmH2O, the investigator manipulated the apparatus to try to reposition it. If air still leaked, another attempt was made using a SLIPA one size larger until an OLP >15 cmH2O was achieved in up to three attempts. After insertion, the investigator measured the inspiratory and expiratory tidal volume. Post-operatively, the presence of blood or regurgitated fluid on the device was evaluated.

Results

OLP for group T was higher than that of group H (p=0.009). The need for manipulation and the leak fraction was higher in group H than in group T (p=0.008 and 0.034, respectively). The degree of insertion difficulty, number of trials and incidence of blood and regurgitated fluid on the device were similar between the two groups.

Conclusions

Both the width and height of thyroid cartilage can be used for selecting the optimal SLIPA size. (Hong Kong j.emerg.med. 2015;22:303-311)

Comparison Between the Cobra Perilaryngeal Airway and Laryngeal Mask Airways Under General Anesthesia: A Systematic Review and Meta-analysis

The complication rate and efficacy of the Cobra Perilaryngeal Airway (CobraPLA) and laryngeal mask airways (LMAs®) have been evaluated in the published literature, but the conclusions have been inconsistent. The aim of this systematic review and meta-analysis was thus to assess the performance of the CobraPLA and LMAs under general anesthesia. We searched PubMed, Embase, and the Cochrane Library for randomized controlled trials comparing the CobraPLA with LMAs under general anesthesia. The LMAs used for comparison were the classic LMA (CLMA) and the unique LMA (ULMA). The random effect model was used if heterogeneity was observed, otherwise the fixed effect model was used. Seventeen randomized controlled trials were included; number of studies analyzed for each result are different and were up to 10. The current result suggests that no significant difference between the devices in the insertion success rate at the first attempt. The success rate of first insertion of the CobraPLA was not different from the rates for the CLMA and the ULMA (relative risk: 0.95, 95% confidence interval [CI], 0.91-1.00). CobraPLA insertion was not different from CLMA and ULMA insertion. The CobraPLA provided an oropharyngeal leak pressure higher than that provided by the CLMA (weight mean difference: 3.90, 95% CI, [1.59-6.21] cmH2O) and ULMA (weight mean difference: 6.57, 95% CI, [4.30-8.84] cmH2O). We also found a higher likelihood of blood staining in the airway with the CobraPLA than with the CLMA. In our research, the principal finding of our meta-analysis is that the success rate of first insertion of the CobraPLA was not different from the rate for each of the CLMA and the ULMA, which featured a short learning curve implying its ease of insertion. There was also no significant difference in the incidence of the best view (with a score of 4) obtained with the CobraPLA compared with the other 2 devices. The CobraPLA does seem to be superior to the CLMA and ULMA in providing a higher oropharyngeal leak pressure. The data were insufficient to establish differences in airway adverse events between the groups except for blood staining in the devices, although mucosal trauma occurred more frequently with the Cobra PLA device than with the CLMA and the ULMA.

Laryngeal tube suction for airway management during in-hospital emergencies

OBJECTIVE:

The role of supraglottic airway devices in emergency airway management is highlighted in international airway management guidelines. We evaluated the application of the new generation laryngeal tube suction (LTS-II/LTS-D) in the management of in-hospital unexpected difficult airway and cardiopulmonary resuscitation.

METHODS:

During a seven-year period, patients treated with a laryngeal tube who received routine anesthesia and had an unexpected difficult airway (Cormack Lehane Grade 3-4), who underwent cardiopulmonary resuscitation, or who underwent cardiopulmonary resuscitation outside the operating room and had a difficult airway were evaluated. Successful placement of the LTS II/LTS-D, sufficient ventilation, time to placement, number of placement attempts, stomach content, peripheral oxygen saturation/end-tidal carbon dioxide development (SpO2/etCO2) over 5 minutes, subjective overall assessment and complications were recorded.

RESULTS:

In total, 106 adult patients were treated using an LTS-II/LTS-D. The main indication for placement was a difficult airway (75%, n=80), followed by cardiopulmonary resuscitation (25%, n=26) or an overlap between both (18%, n=19). In 94% of patients (n=100), users placed the laryngeal tube during the first attempt. In 93% of patients (n=98), the tube was placed within 30 seconds. A significant increase in SpO2 from 97% (0-100) to 99% (5-100) was observed in the whole population and in cardiopulmonary resuscitation patients. The average initial etCO2 of 39.5 mmHg (0-100 mmHg) decreased significantly to an average of 38.4 mmHg (10-62 mmHg) after 5 minutes. A comparison of cardiopulmonary resuscitation patients with non-cardiopulmonary resuscitation patients regarding gastric contents showed no significant difference.

CONCLUSIONS:

LTS-D/LTS-II use for in-hospital unexpected difficult airway management provides a secure method for primary airway management until other options such as video laryngoscopy or fiber optic intubation become available.

Inter-center comparison of EasyTube and endotracheal tube during general anesthesia in minor elective surgery

Background

The EasyTube^® (EzT) is a supraglottic airway device (SAD) enabling ventilation irrespective of its placement into the esophagus or trachea. Data obtained on SADs from multicenter studies, performed in highly specialized centers cannot always be transferred to other sites. However, data on comparability of different sites are scarce. This study focused on inter-site variability of ventilatory and safety parameters during general anesthesia with the EzT.

Methods

400 patients with ASA physical status I-II undergoing general anesthesia for elective surgery in four medical centers (EzT group (n = 200), ETT group (n = 200)). Mallampati classification, success of insertion, insertion time, duration of ventilation, number of insertion attempts, ease of insertion, tidal volumes, leakage, hemodynamic parameters, oxygenation, and complications rates with the EasyTube (EzT) or endotracheal tube (ETT) in comparison within the sites and in between the sites were recorded.

Results

Intra-site and inter-site comparison of insertion success as primary outcome did not differ significantly. The inter-site comparison of expiratory minute volumes showed that the volumes achieved over the course of anesthesia did not differ significantly, however, mean leakage at one site was significantly higher with the EzT (0.63 l/min, p = 0.02). No significant inter-site differences in heart rate, blood pressure, or oxygenation were observed. Sore throat and blood on the cuff after removal of the device were the most frequent complications with significantly more complications at one site with the EzT (p = 0.01) where insertion was also reported significantly more difficult (p = 0.02).

Conclusion

Performance of the EzT but not the ETT varied between sites with regard to insertion difficulty, leakage, and complications but not insertion success, ventilation, hemodynamics, and oxygenation parameters in patients with ASA physical status 1–2 during general anesthesia undergoing minor elective surgery.

The EasyTube during general anesthesia for minor surgery: A randomized, controlled trial

BACKGROUND

The EasyTube (EzT) is a supraglottic airway device that is used for emergency airway situations. Ventilation during general anesthesia should also be feasible, but literature on the EzT is scarce. We evaluated the EzT in comparison with the endotracheal tube (ETT) in its use during general anesthesia in a comparative study.

METHODS

A total of 400 patients with American Society of Anesthesiologists (ASA) physical status I to II scheduled for minor surgery in 4 centers were randomized for ventilation via the ETT or EzT.

RESULTS

In all patients, the EzT and the ETT could be inserted within 3 attempts. In all EzT patients, the inspiratory and expiratory minute volumes (6.64 ± 0.71 and 6.34 ± 0.69 L/min) were sufficient to reach target oxygenation values, similar to ETT patients (P  =  .59). Mean peak pressure, mean plateau pressure, and mean dynamic compliance did not differ between the groups. Sore throat and blood on the cuff after removal were the most frequent complications in both groups.

CONCLUSION

Ventilation for up to 1 hour during general anesthesia in patients with ASA physical status I to II with the EzT is feasible and safe.

Continuous ventilation during intubation through a supraglottic airway device guided by fiberoptic bronchoscopy: a observational assessment

INTRODUCTION

supraglottic airway devices remain, despite advances in video laryngoscopy, important tools in the management of unexpected difficult airways. Intubation through a functioning supraglottic airway device with the aid of a fiberoptic bronchoscope is a well-known technique usually performed in apnoea. With a simple modification, the patient can be ventilated during this procedure.

METHODS

In this observational study, Tracheal intubation Assisted by Bronchoscopy And Sad during Continuous Oxygenation (TABASCO) was performed as part of department training routine in 26 elective, fasted patients. A supraglottic airway device was used as a conduit for an endotracheal tube.

RESULTS

All patients were easily intubated and ventilation was maintained during the procedure. The gap between the outer diameter of the fiberoptic bronchoscope and the inner diameter of the endotracheal tube was more than 2 mm in 25 of 26 patients. Effective ventilation was confirmed by clinical signs, capnography and pressure-volume curves. No signs of airtrapping occurred.

DISCUSSION

No adverse events were observed during this form of airway management in this small series of elective and fasted patient when performed by an anaesthesiologist experienced in fiberoptic intubation. A gap between fiberoptic bronchoscope and endotracheal tube inner lumen seems to be prerequisite for easy ventilation through the supraglottic airway. In trained hands, this technique can be a means to secure an airway with an intubating bronchoscope without pausing ventilations. A prerequisite for this is a well-functioning supraglottic airway device.

The i-gel Supraglottic Airway as a Conduit for Fibreoptic Tracheal Intubation – A Randomized Comparison with the Single-use Intubating Laryngeal Mask Airway and CTrach Laryngeal Mask in Patients with Predicted Difficult Laryngoscopy

Fibreoptic intubation through a supraglottic airway is an alternative plan for airway management in difficult or failed laryngoscopy. The aim of this study was to compare three supraglottic airways as conduits in patients with at least one predictor for difficult laryngoscopy. The i-gel was compared with the single-use intubating laryngeal mask airway (sILMA) and CTrach laryngeal mask in 120 adult patients scheduled for elective surgeries under general anaesthesia using a prospective, randomized and single-blinded design. Primary outcome was success rate of tracheal intubation through the device, while secondary outcomes were times required for device insertion and tracheal tube placement, fibreoptic scores and the incidence of perioperative complications and postoperative complaints. The success rates showed no statistical difference between devices (i-gel 100%, CTrach 97.5%, ILMA 95%). Insertion time was shortest for the i-gel (12.4 s) compared with ILMA (19.3 s) and CTrach (24.4 s). Intubation time was shorter in the i-gel group (29.4 s) in comparison with the CTrach (39.8 s, p<0.05) and sILMA (51.9 s, p<0.001) groups. Best fibreoptic scores were observed also in the i-gel group. In total, 24 patients (20%) presented with difficult laryngoscopy. The i-gel showed significantly shorter times for insertion and fibreoptic intubation than the other two devices in this group. No difference was observed in the incidence of postoperative complaints. The i-gel is a suitable alternative to the sILMA and CTrach for fibrescope-guided tracheal intubation. Shorter insertion and intubation times with the i-gel may provide advantage in case of difficult oxygenation.

Insertion Success of the Laryngeal Tube in Emergency Airway Management

Background. Emergency airway management (AM) is a priority when resuscitating critically ill or severely injured patients. The goal of this study was to determine the success rates of LT insertion during AM. Methods. Studies that included LT first-pass insertion (FPI) and overall-pass insertion (OPI) success by emergency medical services and in-hospital providers performing AM for emergency situations as well as for scheduled surgery published until July 2014 were searched systematically in Medline. Results. Data of 36 studies (n = 1,897) reported a LT FPI success by physicians of 82.5% with an OPI success of 93.6% (p < 0.001). A cumulative analysis of all 53 studies (n = 3,600) led to FPI and OPI success of 80.1% and 92.6% (p < 0.001), respectively. The results of 26 studies (n = 2,159) comparing the LT with the laryngeal mask airway (LMA) demonstrated a FPI success of 77.0 versus 78.7% (p = 0.36) and an OPI success of 92.2 versus 97.7% (p < 0.001). Conclusion. LT insertion failed in the first attempt in one out of five patients, with an overall failure rate in one out of 14 patients. When compared with the LT, the LMA had a cumulative 5.5% better OPI success rate.

Comparison between supraglottic airway devices and endotracheal tubes in patients undergoing laparoscopic surgery: A systematic review and meta-analysis

BACKGROUND

Comparisons between the efficacies of supraglottic airway devices (SGAs) and endotracheal tubes (ETTs) in patients undergoing laparoscopic surgeries have yielded conflicting results. Therefore, in this meta-analysis, we compared the clinical performance and incidence of complications between SGAs and ETT intubation in laparoscopic surgery.

METHODS

A comprehensive search was conducted using MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and Google Scholar to identify randomized controlled trials that compared SGAs with ETTs in laparoscopic surgery.

RESULTS

In total, 1433 patients from 17 studies were included in the final analysis. SGAs and ETTs showed no difference in insertion success rate on the first attempt (relative risk [RR] 1.01, 95% confidence interval [CI] 0.99-1.03), insertion time (standardized mean difference 1.57, 95% CI -3.74 to 0.61), and oropharyngeal leak pressure (OLP) (mean difference -2.54, 95% CI -7.59 to 2.50). The incidence of desaturation (RR 3.65, 95% CI 1.39-9.62), gastric insufflations (RR 0.90, 95% CI 0.48-1.71), regurgitation (RR 0.98, 95% CI 0.02-49.13), and aspiration (RR 0.99, 95% CI 0.01-78.4) also showed no intergroup differences. However, the incidence of laryngospasm (RR 3.12, 95% CI 1.29-7.52), cough at removal (RR 6.68, 95% CI 4.70-9.48), dysphagia (RR 1.47, 95% CI 1.12-1.95) or dysphonia (RR 4.41, 95% CI 1.25-15.55), sore throat (RR 1.60, 95% CI 1.33-1.93), and hoarseness (RR 1.53, 95% CI 1.29-1.81) was higher in the ETT group than in the SGA group.

CONCLUSIONS

The incidence of laryngospasm, cough at removal, dysphagia or dysphonia, sore throat, and hoarseness were higher in the ETT group than in the SGA group. However, the groups showed no differences in the rate of insertion success on the first attempt, insertion time, OLP, and other complications. Therefore, SGAs might be clinically more useful as effective airways in laparoscopic surgery.

Comparative Efficacy of the Air-Q Intubating Laryngeal Airway during General Anesthesia in Pediatric Patients: A Systematic Review and Meta-Analysis

Air-Q® (air-Q) is a supraglottic airway device which can be used as a guidance of intubation in pediatric as well as in adult patients. We evaluated the efficacy and safety of air-Q compared to other airway devices during general anesthesia in pediatric patients by conducting a systematic review and meta-analysis. A total of 10 studies including 789 patients were included in the final analysis. Compared with other supraglottic airway devices, air-Q showed no evidence for a difference in leakage pressure and insertion time. The ease of insertion was significantly lower than other supraglottic airway devices. The success rate of intubation was significantly lower than other airway devices. However, fiberoptic view was better through the air-Q than other supraglottic airway devices. Therefore, air-Q could be a safe substitute for other airway devices and may provide better fiberoptic bronchoscopic view.

Preheating of streamlined liner of pharyngeal airway (SLIPA) reduced the related complications: a randomized control study

This study was designed to verify whether preheating could decrease the complications that may be associated with the use of streamlined liner of pharyngeal airway (SLIPA). We evaluated the incidence of sore throat, maximum sealing pressure, hoarseness and blood stains after preheating of SLIPA. Eighty patients scheduled for hysteroscopic surgery to whom the SLIPA was considered suitable were randomly allocated to preheating group or control group. The SLIPA in preheating group was placed in the incubator at 42 °C. The control group temperature was 24 °C. The mean maximum sealing pressure and duration of insertion were compared. Patients were interviewed at recovery room about sore throat and other complications. There were statistical differences in incidence of sore throat, severity of sore throat and blood stains between groups. However there was no statistical difference in the maximum sealing pressure. Our results suggest preheating of the SLIPA decreased the complications related with the insertion of SLIPA. Clinical Trials.gov Identifier NCT02539485.

Advances in supraglottic airway devices for the management of difficult airways in children

There are innumerable tools and devices available to facilitate airway management and life-saving gas exchange of the patient's lungs. Over the years, various designs and generations of supraglottic airway devices have proven to be effective in accomplishing this function. Their application has grown beyond the original purpose of controlling the normal pediatric airway without tracheal intubation, and has been incorporated in the difficult airway management algorithms of anesthesia societies around the world based on clear evidence of efficacy. Older supraglottic airway devices since the 1980's have been validated in multiple clinical trials to be safe and effective in the pediatric population, however there is also sufficient evidence that the newer designs have features that help overcome some limitations. These newer designs and features are effective in managing both the normal and difficult pediatric airway, and will be discussed in this comprehensive review.

I-gel Versus LMA-Fastrach Supraglottic Airway for Flexible Bronchoscope-Guided Tracheal Intubation Using a Parker (GlideRite) Endotracheal Tube: A Randomized Controlled Trial

BACKGROUND

The I-gel (IG) supraglottic airway device is a reliable way to establish an airway. Its large ventilation lumen allows for easy passage of an endotracheal tube. With the use of a flexible bronchoscope, the IG offers a good visualization of the laryngeal inlet. This prospective randomized study aims to compare the success rate of flexible bronchoscope-guided tracheal intubation using either the IG or the LMA-Fastrach (FT) laryngeal masks.

METHODS

One hundred twenty patients requiring general anesthesia were randomized to 1 of the 2 study groups: IG or FT. After anesthesia induction, the assigned laryngeal mask was inserted to obtain adequate ventilation. We then proceeded to a flexible bronchoscope-guided intubation through the supraglottic device. Tracheal intubation and laryngeal mask insertion success rates were noted, as well as the time required for these manipulations. The view of the laryngeal inlet was graded for each intubation attempt.

RESULTS

Sixty patients were assigned to each study group. The intubation success rates were similar between the IG and the FT groups (100 % vs 95.0 % at first attempt; P = 0.12). The times required for tracheal intubation were significantly lower in the IG group (30 ± 11 seconds vs 50 ± 21 seconds; P < 0.0001). Glottic visualization was better in the IG group, with a significantly higher percentage of grade 1 visualization (63.3% vs 3.3%; P < 0.0001) and a lower percentage of grade 3 visualization (1.7% vs 60.0%; P < 0.0001), than that in the FT group.

CONCLUSIONS

The use of the IG supraglottic airway device as a conduit for flexible bronchoscope-guided tracheal intubation results in a success rate equivalent to the use of the LMA-FT. However, the IG allows for shorter intubation times and a better visualization of the glottic opening compared with the LMA-FT.