Tracheal intubation with a flexible intubation scope versus other intubation techniques for obese patients requiring general anaesthesia

Impact of airway devices and emergency airway techniques characteristics on airway adverse events in mainland China: a cross-sectional study

BACKGROUND

Novel airway devices are becoming widely available, yet it is unclear whether the techniques or preferences of airway practitioners for airway management have been impacted. Given these facts, a cross-sectional study of the current status of airway management in mainland China was conducted and compared with previous survey findings.

METHODS

The national survey was conducted from November 7th to November 28th, 2022. An electronic survey was sent to the New Youth Anesthesia Forum to examine the availability of airway devices, preference for front-of-neck access (FONA) techniques, the incidence of adverse airway events, and the status of airway management training.

RESULTS

Questionnaires were completed by 3783 respondents, with a response rate of 72.14%. So far, the availability of optical airway devices has improved dramatically, with the availability of videolaryngoscopes reaching 97.18%. When encountering "cannot intubate, cannot ventilate" (CICV) scenarios, the majority of respondents would prefer needle cricothyrotomy to establish FONA. However, less than a quarter of respondents had actually performed it. Moreover, the incidence of airway adverse events from 2016 to 2022 was 11.48%, of which 5.13% were brain damage or death. Multivariate logistic regression analysis revealed that the ability to perform FONA techniques (odds ratio [OR] 0.23, 95% CI: 0.16, 0.32; P<0.001) and the availability of difficult airway management carts or kits (OR 0.59, 95% CI 0.41, 0.85; P=0.005) were associated with a lower incidence of airway adverse events.

CONCLUSIONS

Optical airway devices can overcome some of the challenges posed by difficult airways, yet the CICV scenario remains a major obstacle. The future focus of airway management should be training, particularly for complicated emergency airway techniques.

A Comparison of Miller Straight Blade and Macintosh Blade Laryngoscopes for Intubation in Morbidly Obese Patients

The primary objective of this study was to demonstrate whether the Miller blade laryngoscope could provide better visualization of the vocal cords in morbidly obese patients than the Macintosh blade laryngoscope. The secondary objective was to identify the patient-measured factors associated with better visualization of the vocal cords when using the Miller vs. Macintosh blade, as well as whether the application of external pressure might improve the visibility of the glottis during intubation. A prospective, observational study encompassing 110 patients with a BMI > 40 undergoing elective bariatric surgery and intubation procedure was performed. The evaluation of the vocal cords was performed according to the Cormack-Lehane scale and POGO scale in the same patient during intubation, performed with a Miller and a Macintosh blade laryngoscope, in a random matter. The following parameters were assessed: body weight, height, BMI, neck circumference, thyromental distance, sternomental distance, mouth opening, and Mallampati scale and their impact on visualization of the vocal cords using the Miller blade without the application of external pressure. The Miller blade provides an improved view of the glottis compared to the Macintosh blade measured with both the Cormac-Lehane scale (45 (40.91%) without external pressure application on the larynx, and 18 (16.36%) with external pressure application on the larynx) and the POGO scale (45 (40.91%) without external pressure application on the larynx, and 19 (17.27%) with external pressure application on the larynx). The application of laryngeal pressure improved the view of the glottis. Among the measured features, a significant improvement in the visibility of the glottis could be found in patients with a BMI over 44.244 kg/m2 and a neck circumference over 46 cm. To conclude, the usage of the Miller blade improves the visibility of the glottis compared to the Macintosh blade in morbidly obese patients. The recommendation to use the Miller blade in this group of patients requires further investigation, taking into account the effectiveness of the intubation. Trial Registration: NCT05494463.

Styletubation in Bariatric Surgery: A Case Report

Direct laryngoscopes and videolaryngoscopes are the dominant endotracheal intubation tools. The styletubation technique (using a video-assisted intubating stylet) has shown its advantages in terms of short intubation time, high success rate, less required stimulation, and operator satisfaction. The learning curve can be steep but is easily overcome if technical pitfalls are avoided. Conditions that make styletubation challenging include secretions/blood, short/stiff neck, restricted mouth opening and cervical spine mobility, anatomical abnormalities over head and neck regions, obesity, etc. In this clinical report, we present the effectiveness and efficiency of the routine use of the styletubation for tracheal intubation in a super-super-obese patient (BMI 103 kg/m2) undergoing bariatric surgery with laparoscopic sleeve gastrectomy.

Fibreoptic intubation in airway management: a review article

Since the first use of the flexible fibreoptic bronchoscope, a plethora of new airway equipment has become available. It is essential for clinicians to understand the role and limitations of the available equipment to make appropriate choices. The recent 4th National Audit Project conducted in the United Kingdom found that poor judgement with inappropriate choice of equipment was a contributory factor in airway morbidity and mortality. Given the many modern airway adjuncts that are available, we aimed to define the role of flexible fibreoptic intubation in decision-making and management of anticipated and unanticipated difficult airways. We also reviewed the recent literature regarding the role of flexible fibreoptic intubation in specific patient groups who may present with difficult intubation, and concluded that the flexible fibrescope maintains its important role in difficult airway management.

Guidelines for Perioperative Care in Bariatric Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations

BACKGROUND

During the last two decades, an increasing number of bariatric surgical procedures have been performed worldwide. There is no consensus regarding optimal perioperative care in bariatric surgery. This review aims to present such a consensus and to provide graded recommendations for elements in an evidence-based "enhanced" perioperative protocol.

METHODS

The English-language literature between January 1966 and January 2015 was searched, with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohort studies. Selected studies were examined, reviewed and graded. After critical appraisal of these studies, the group of authors reached a consensus recommendation.

RESULTS

Although for some elements, recommendations are extrapolated from non-bariatric settings (mainly colorectal), most recommendations are based on good-quality trials or meta-analyses of good-quality trials.

CONCLUSIONS

A comprehensive evidence-based consensus was reached and is presented in this review by the enhanced recovery after surgery (ERAS) Society. The guidelines were endorsed by the International Association for Surgical Metabolism and Nutrition (IASMEN) and based on the evidence available in the literature for each of the elements of the multimodal perioperative care pathway for patients undergoing bariatric surgery.

Videolaryngoscopy versus direct laryngoscopy for adult patients requiring tracheal intubation

BACKGROUND

Successful tracheal intubation during general anaesthesia traditionally requires a line of sight to the larynx attained by positioning the head and neck and using a laryngoscope to retract the tongue and soft tissues of the floor of the mouth. Difficulties with intubation commonly arise, and alternative laryngoscopes that use digital and/or fibreoptic technology have been designed to improve visibility when airway difficulty is predicted or encountered. Among these devices, a rigid videolaryngoscope (VLS) uses a blade to retract the soft tissues and transmits a lighted video image to a screen.

OBJECTIVES

Our primary objective was to assess whether use of videolaryngoscopy for tracheal intubation in adults requiring general anaesthesia reduces risks of complications and failure compared with direct laryngoscopy. Our secondary aim was to assess the benefits and risks of these devices in selected population groups, such as adults with obesity and those with a known or predicted difficult airway.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase on 10 February 2015. Our search terms were relevant to the review question and were not limited by outcomes. We carried out clinical trials register searches and forward and backward citation tracking. We reran the search on 12 January 2016; we added potential new studies of interest from the 2016 search to a list of 'Studies awaiting classification', and we will incorporate these studies into the formal review during the review update.

SELECTION CRITERIA

We considered all randomized controlled trials and quasi-randomized studies with adult patients undergoing laryngoscopy performed with a VLS or a Macintosh laryngoscope in a clinical, emergency or out-of-hospital setting. We included parallel and cross-over study designs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data, consulting a third review author to resolve disagreements. We used standard Cochrane methodological procedures, including assessment of risk of bias.

MAIN RESULTS

We included 64 studies identified during the 2015 search that enrolled 7044 adult participants and compared a VLS of one or more designs with a Macintosh laryngoscope. We identified 38 studies awaiting classification and seven ongoing studies. Of the 64 included studies, 61 included elective surgical patients, and three were conducted in an emergency setting. Among 48 studies that included participants without a predicted difficult airway, 15 used techniques to simulate a difficult airway. Seven recruited participants with a known or predicted difficult airway, and the remaining studies did not specify or included both predicted and not predicted difficult airways. Only two studies specifically recruited obese participants. It was not possible to blind the intubator to the device, and we noted a high level of inevitable heterogeneity, given the large number of studies.Statistically significantly fewer failed intubations were reported when a VLS was used (Mantel-Haenszel (M-H) odds ratio (OR), random-effects 0.35, 95% confidence Interval (CI) 0.19 to 0.65; 38 studies; 4127 participants), and fewer failed intubations occurred when a VLS was used in participants with an anticipated difficult airway (M-H OR, random-effects 0.28, 95% CI 0.15 to 0.55; six studies; 830 participants). We graded the quality of this evidence as moderate on the basis of the GRADE system. Failed intubations were fewer when a VLS was used in participants with a simulated difficult airway (M-H OR, random-effects 0.18, 95% CI 0.04 to 0.77; nine studies; 810 participants), but groups with no predicted difficult airway provided no significant results (M-H OR, random-effects 0.61, 95% CI 0.22 to 1.67; 19 studies; 1743 participants).Eight studies reported on hypoxia, and only three of these described any events; results showed no differences between devices for this outcome (M-H OR, random-effects 0.39, 95% CI 0.10 to 1.44; 1319 participants). Similarly, few studies reported on mortality, noting no differences between devices (M-H OR, fixed-effect 1.09, 95% CI 0.65 to 1.82; two studies; 663 participants), and only one study reporting on the occurrence of respiratory complications (78 participants); we graded these three outcomes as very low quality owing to lack of data. We found no statistically significant differences between devices in the proportion of successful first attempts (M-H OR, random-effects 1.27, 95% CI 0.77 to 2.09; 36 studies; 4731 participants) nor in those needing more than one attempt. We graded the quality of this evidence as moderate. Studies reported no statistically significant differences in the incidence of sore throat in the postanaesthesia care unit (PACU) (M-H OR, random-effects 1.00 (95% CI 0.73 to 1.38); 10 studies; 1548 participants) nor at 24 hours postoperatively (M-H OR random-effects 0.54, 95% CI 0.27 to 1.07; eight studies; 844 participants); we graded the quality of this evidence as moderate. Data combined to include studies of cross-over design revealed statistically significantly fewer laryngeal or airway traumas (M-H OR, random-effects 0.68, 95% CI 0.48 to 0.96; 29 studies; 3110 participants) and fewer incidences of postoperative hoarseness (M-H OR, fixed-effect 0.57, 95% CI 0.36 to 0.88; six studies; 527 participants) when a VLS was used. A greater number of laryngoscopies performed with a VLS achieved a view of most of the glottis (M-H OR, random-effects 6.77, 95% CI 4.17 to 10.98; 22 studies; 2240 participants), fewer laryngoscopies performed with a VLS achieved no view of the glottis (M-H OR, random-effects 0.18, 95% CI 0.13 to 0.27; 22 studies; 2240 participants) and the VLS was easier to use (M-H OR, random-effects 7.13, 95% CI 3.12 to 16.31; seven studies; 568 participants).Although a large number of studies reported time required for tracheal intubation (55 studies; 6249 participants), we did not present an effects estimate for this outcome owing to the extremely high level of statistical heterogeneity (I2 = 96%).

AUTHORS' CONCLUSIONS

Videolaryngoscopes may reduce the number of failed intubations, particularly among patients presenting with a difficult airway. They improve the glottic view and may reduce laryngeal/airway trauma. Currently, no evidence indicates that use of a VLS reduces the number of intubation attempts or the incidence of hypoxia or respiratory complications, and no evidence indicates that use of a VLS affects time required for intubation.

A comparison of performance of endotracheal intubation using the Levitan FPS optical stylet or Lary-Flex videolaryngoscope in morbidly obese patients

INTRODUCTION

The use of videolaryngoscopes is recommended for morbidly obese patients. The aim of the study was to evaluate the Levitan FPS optical stylet (Levitan) vs Lafy-Flex videolaryngoscope (Lary-Flex) in a group of MO patients.

METHODS

Seventy-nine MO (BMI > 40 kg m(-2)) patients scheduled for bariatric surgery were included in the study and randomly allocated to the Levitan FPS or Lary-Flex group. The primary endpoint was time to intubation and evaluation laryngoscopic of glottic view. Anesthesiologists were asked to evaluate the glottic view first under direct laryngoscopy using the videolaryngoscope as a standard laryngoscope (monitor display was excluded from use) and then using devices. The secondary endpoint was the cardiovascular response to intubation and the participant's evaluation of such devices.

RESULTS

The time to intubation was 8.572.66 sec. versus 5.790.2 sec. for Levitan and Lary-Flex, respectively (P < 0.05). In all cases of CL grade >1 under direct laryngoscopy, the study devices improved CL grade to 1. The Levitan FPS produced a greater cardiovascular response than the Lary-Flex videolaryngoscope.

CONCLUSION

The Lary-Flex videolaryngoscope and the Levitan FPS optical stylet improve the laryngeal visualization in morbidly obese patients, allowing for fast endotracheal intubation, but Lary-Flex produces less cardiovascular response to intubation attempt.

The use of VivaSight™ single lumen endotracheal tube in morbidly obese patients undergoing laparoscopic sleeve gastrectomy

Background

The population of obese patients is progressively growing and bariatric operations are becoming increasingly common. Morbidly obese patients require special anesthetic care and are often considered to be difficult to ventilate and intubate. The VivaSight™ Single Lumen tube is an endotracheal tube with a camera embedded in its tip. The view from the tip appears continuously on a monitor in the anesthesiologist's vicinity. The aim of this study was to assess the VivaSight™ in comparison with conventional endotracheal tube as an aid in the intubation and surveillance of tube position during surgery of obese patients.

Methods

This is a prospective study of 72 adult obese patients who underwent laparoscopic sleeve gastrectomy. The patients were randomly assigned to be intubated by either the VivaSight™ (40 patients, test group) or a conventional endotracheal tube (32 patients, control group). Data on the patients, the pre-operative airway evaluation, the endotracheal intubation and the post-operative outcome were collected and compared.

Results

The Mallampati scores were significantly higher in the test group than in the control group. Endotracheal intubation took 29 ± 10 and 24 ± 8 seconds using the VivaSight™ and a conventional tube respectively (p = 0.02). Three of the patients in the control group, while none of those in the test group, had soft tissue injury (p < 0.05).

Conclusion

We found the VivaSight™ SL to be helpful in the endotracheal intubation and continuous surveillance of tube position in morbidly obese patients undergoing laparoscopic sleeve gastrectomy.