Evaluation of a novel, low-cost, 3D printed video laryngoscope with borescope in anesthetized Beagle dogs

OBJECTIVE

To develop and evaluate a low-cost three-dimensional (3D)-printed video laryngoscope (VLVET) for use with a commercial borescope.

STUDY DESIGN

Instrument development and pilot study.

ANIMALS

A total of six adult male Beagle dogs.

METHODS

The VLVET consisted of a laryngoscope handle and a Miller-type blade, and a detachable camera holder that attached to various locations along the blade. The laryngoscope and camera holder were 3D-printed using black polylactic acid filament. Dogs were premedicated with intravenous (IV) medetomidine (15 μg kg-1) and anesthesia induced with IV alfaxalone (1.5 mg kg-1). The VLVET, combined with a borescope, was used for laryngeal visualization and intubation. Performance was evaluated by comparing direct and video-assisted views in sternal recumbency. The borescope camera was sequentially positioned at 2, 4, 6, 8 and 10 cm from the blade tip (distanceLARYNX-CAM), which was placed on the epiglottis during intubation or laryngoscopy. At the 10 cm distanceLARYNX-CAM, laryngeal visualization was sequentially scored at inter-incisor gaps of 10, 8, 6, 4 and 2 cm. Laryngeal visualization scores (0-3 range, with 0 = obstructed and 3 = unobstructed views) were statistically analyzed using the Friedman's test.

RESULTS

Under direct visualization, the 2 cm distanceLARYNX-CAM had a significantly lower score compared with all other distanceLARYNX-CAM (all p = 0.014) because the view was obstructed by the camera holder and borescope camera. With both direct and camera-assisted views, visualization scores were higher at inter-incisor gaps ≥ 4 cm compared with 2 cm (all p < 0.05).

CONCLUSIONS AND CLINICAL RELEVANCE

During laryngoscopy and intubation, the VLVET and borescope facilitated both direct and video laryngoscopy at distanceLARYNX-CAM in Beagle dogs when inter-incisor gaps were ≥ 4 cm.

Individualized rotation of left double lumen endobronchial tube to improve placement success rate: a randomized controlled trial

BACKGROUND

In conventional practice, the left double lumen tube (DLT) is rotated 90° counterclockwise when the endobronchial cuff passes glottis. Success rate upon the first attempt is < 80%, likely owing to varying morphology of the bronchial bifurcation.

METHODS

We conducted a randomized controlled trial to compare 90° counterclockwise rotation versus individualized degree of rotation in adult patients undergoing elective thoracic surgery using left DLT. The degree of rotation in the individualized group was based on the angle of the left main bronchi as measured on computed tomography (CT). The primary outcome was the first attempt left DLT placement success rate.

RESULTS

A total of 556 patients were enrolled: 276 in the control group and 280 in the individualized group. The average angle of the left main bronchi was 100.6±9.5° (range 72° to 119°). The first attempt left DLT placement success rate was 82.6% (228/276) in the control group versus 91.4% (256/280) in the individualized group (P=0.02, χ2 test). The rate of carina mucosal injury, as measured at 30 min after the start of surgery under fibreoptic bronchoscopy, was significantly lower in individualized group than control group (14.0% versus 19.6%, P=0.041). The individualized group also had lower rate of postoperative sore throat (29.4% versus 44.0%, P<0.001) and hoarseness (16.8% versus 24.7%, P＜0.05).

CONCLUSIONS

Individualized rotation of left DLT based on the angle of the left main bronchi on preoperative CT increased first attempt success rate in adult patients undergoing elective thoracic surgery.

TRIAL REGISTRATION

The trial is registered at Chinese Clinical Trial Registry (ChiCTR2100053349; principal investigator Xiang Quan, date of registration November 19, 2021).

Comparison of video laryngoscope, video stylet, and flexible videoscope for transoral endotracheal intubation in patients with difficult airways: a randomized, parallel-group study

BACKGROUND

The 2022 ASA guidelines recommend the video laryngoscope, video stylet, and flexible videoscope as airway management tools. This study aims to compare the efficacy of three airway devices in intubating patients with difficult airways.

METHODS

A total of 177 patients were selected and randomized into the following three groups: the video laryngoscope group (Group VL, n = 59), video stylet group (Group VS, n = 59), and flexible videoscope group (Group FV, n = 59). The success rate of the first-pass intubation, time of tracheal intubation, level of glottic exposure, and occurrence of intubation-related adverse events were recorded and analyzed.

RESULTS

All patients were successfully intubated with three devices. The first-pass intubation success rate was significantly higher in Groups VS and FV than in Group VL (96.61% vs. 93.22% vs. 83.05%, P < 0.01), but it was similar in the first-pass intubation success rate between Groups VS and FV(P > 0.05). The number of patients categorized as Wilson-Cormack-Lehane grade I-II was fewer in Group VL than in Groups VS and FV (77.97% vs. 98.30% vs. 100%, P = 0.0281). The time to tracheal intubation was significantly longer in Group FV(95.20 ± 4.01) than in Groups VL(44.56 ± 4.42) and VS(26.88 ± 4.51) (P < 0.01). No significant differences were found among the three groups in terms of adverse intubation reactions (P > 0.05).

CONCLUSIONS

In patients with difficult airways requiring intubation, use of the video stylet has the advantage of a relatively shorter intubation time, and the flexible videoscope and video stylet yield a higher first-pass intubation success rate and clearer glottic exposure than the use of the video laryngoscope.

TRIAL REGISTRATION

Chinese Clinical Trial Registry. No: ChiCTR2200061560, June 29, 2022.

Infrared flashing light through the cricothyroid membrane as guidance to awake intubation with a flexible bronchoscope: A randomised cross-over study

BACKGROUND

In case of distorted airway anatomy, awake intubation with a flexible bronchoscope can be extremely difficult or even impossible. To facilitate this demanding procedure, an infrared flashing light source can be placed on the patient's neck superficial to the cricothyroid membrane. The light travels through the skin and tissue to the trachea, from where it can be registered by the advancing bronchoscope in the pharynx and seen as flashing white light on the monitor. We hypothesised that the application of this technique would allow more proximal and easier identification of the correct pathway to the trachea in patients with severe airway pathology.

METHODS

As part of awake intubation, patients underwent insertion of a flexible video bronchoscope via the mouth into the trachea. The procedure was performed twice, in random order in each patient, with and without the aid of the transcutaneous flashing infrared light. All insertions were video recorded to determine at which anatomical landmark within the airway the correct pathway was identified. The videos are accessible via this link: https://airwaymanagement.dk/infrared_comparative. The predefined landmarks were in successive order: oral cavity, oro-pharynx, tip of epiglottis, arytenoid cartilages, false cords, vocal cords and trachea, as well as the spaces between them.

RESULTS

Twenty-two patients had a total of 44 awake insertions with the flexible bronchoscope. The median anatomical level, at which correct identification of the trachea was obtained on the monitor, was, past the epiglottis, with the conventional technique, and at the level of the oropharynx, when using the infrared flashing light (p = .005). The time until the flashing light or the vocal cords were seen was 21 (22) S, mean (SD), and 48 (62) S, during the insertion with and without infrared flashing light activated, respectively (p = .005). Endoscopists rated it easier (p = .001) to recognise the entrance to the trachea in the infrared-group.

CONCLUSION

During awake intubation of patients with airway pathology, the application of trans-cricothyroid infrared flashing light to guide the insertion of a flexible bronchoscope significantly facilitated the recognition of the pathway into the trachea and the correct advancement of the flexible endoscope.

REGISTRATION OF CLINICAL TRIAL

NCT03930550.

Educational suitability of new channel-type video-laryngoscope with AI-based glottis guidance system for novices wearing personal-protective-equipment

The aim of this study was to determine which of 4 laryngoscopes, including A-LRYNGO, a newly developed channel-type video-laryngoscope with an embedded artificial intelligence-based glottis guidance system, is appropriate for tracheal intubation training in novice medical students wearing personal protective equipment (PPE).Thirty healthy senior medical school student volunteers were recruited. The participants underwent 2 tests with 4 laryngoscopes: Macintosh, McGrath, Pentax Airway-Scope and A-LRYNGO. The first test was conducted just after a lecture without any hands-on workshop. The second test was conducted after a one-on-one hands-on workshop. In each test, we measured the time required for tracheal intubation, intubation success rate, etc, and asked all participants to complete a short questionnaire.The time to completely insert the endotracheal tube with the Macintosh laryngoscope did not change significantly (P = .177), but the remaining outcomes significantly improved after the hands-on workshop (all P < .05). Despite being novice practitioners with no intubation experience and wearing PPE, the, 2 channel-type video-laryngoscopes were associated with good intubation-related performance before the hands-on workshop (all P < .001). A-LRYNGO's artificial intelligence-based glottis guidance system showed 93.1% accuracy, but 20.7% of trials were guided by the vocal folds.To prepare to manage the airway of critically ill patients during the coronavirus disease 2019 pandemic, a channel-type video-laryngoscope is appropriate for tracheal intubation training for novice practitioners wearing PPE.

Effect of Placement of a Supraglottic Airway Device vs Endotracheal Intubation on Return of Spontaneous Circulation in Adults With Out-of-Hospital Cardiac Arrest in Taipei, Taiwan: A Cluster Randomized Clinical Trial

IMPORTANCE

Prehospital advanced airway management with either initial endotracheal intubation (ETI) or initial supraglottic airway (SGA) insertion in patients with out-of-hospital cardiac arrest (OHCA) remains controversial.

OBJECTIVE

To compare the effectiveness of ETI and SGA in patients with nontraumatic OHCA.

DESIGN, SETTING, AND PARTICIPANTS

The Supraglottic Airway Device vs Endotracheal intubation (SAVE) trial was a multicenter cluster randomized clinical trial conducted in Taipei City, Taiwan. Individuals aged 20 years or older who experienced nontraumatic OHCA requiring advanced airway management and were treated by participating emergency medical service agencies were enrolled from November 11, 2016, to December 31, 2019. The final day of follow-up was February 19, 2020.

INTERVENTIONS

Four advanced life support ambulance teams were divided into 2 randomization clusters, with each cluster assigned to either ETI or SGA in a biweekly period.

MAIN OUTCOMES AND MEASURES

The primary outcome of the SAVE trial was sustained return of spontaneous circulation (ROSC) (≥2 hours) after resuscitation. Secondary outcomes included prehospital ROSC, survival to hospital discharge, and favorable neurologic outcome, defined as a cerebral performance category score less than or equal to 2. Prespecified subgroups and the association between time to advanced airways were explored. Per protocol and intention-to-treat analysis were performed.

RESULTS

A total of 936 patients (517 in the ETI group and 419 in the SGA group) were included in the primary analysis (median age, 77 [IQR, 62-85] years; 569 men [60.8%]). The first-attempt airway success rates were 77% with ETI (n = 413) and 83% with SGA (n = 360). Sustained ROSC was 26.9% (n = 139) in the ETI group vs 25.8% (n = 108) in the SGA group. The odds ratio of sustained ROSC was 1.02 (95% CI, 0.98-1.06) in the ETI group vs SGA group. The odds ratio of ETA vs SGA was 1.04 (95% CI, 1.02-1.07) for prehospital ROSC, 1.00 (95% CI, 0.94-1.06) for survival to hospital discharge, and 0.99 (95% CI, 0.94-1.03) for cerebral performance category scores less than or equal to 2.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, among patients with OHCA, initial airway management with ETI did not result in a favorable outcome of sustained ROSC compared with SGA device insertion.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02967952.

Cuffed versus uncuffed endotracheal tubes for neonates

BACKGROUND

Endotracheal intubation is a commonly performed procedure in neonates, the risks of which are well-described. Some endotracheal tubes (ETT) are equipped with a cuff that can be inflated after insertion of the ETT in the airway to limit leak or aspiration. Cuffed ETTs have been shown in larger children and adults to reduce gas leak around the ETT, ETT exchange, accidental extubation, and exposure of healthcare workers to anesthetic gas during surgery. With improved understanding of neonatal airway anatomy and the widespread use of cuffed ETTs by anesthesiologists, the use of cuffed tubes is increasing in neonates.

OBJECTIVES

To assess the benefits and harms of cuffed ETTs (inflated or non-inflated) compared to uncuffed ETTs for respiratory support in neonates.

SEARCH METHODS

We searched CENTRAL, PubMed, and CINAHL on 20 August 2021; we also searched trial registers and checked reference lists to identify additional studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs), quasi-RCTs, and cluster-randomized trials comparing cuffed (inflated and non-inflated) versus uncuffed ETTs in newborns. We sought to compare 1. inflated, cuffed versus uncuffed ETT; 2. non-inflated, cuffed versus uncuffed ETT; and 3. inflated, cuffed versus non-inflated, cuffed ETT.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal. Two review authors independently assessed studies identified by the search strategy for inclusion, extracted data, and assessed risk of bias. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We identified one eligible RCT for inclusion that compared the use of cuffed (inflated if ETT leak greater than 20% with cuff pressure 20 cm H₂O or less) versus uncuffed ETT. The author provided a spreadsheet with individual data. Among 76 infants in the original manuscript, 69 met the inclusion and exclusion criteria for this Cochrane Review. We found possible bias due to lack of blinding and other bias. We are very uncertain about frequency of postextubation stridor, because the confidence intervals (CI) of the risk ratio (RR) were very wide (RR 1.36, 95% CI 0.35 to 5.25; risk difference (RD) 0.03, -0.11 to 0.18; 1 study, 69 participants; very low-certainty evidence). No neonate was diagnosed with postextubation subglottic stenosis; however, endoscopy was not available to confirm the clinical diagnosis. We are very uncertain about reintubation for stridor or subglottic stenosis because the CIs of the RR were very wide (RR 0.27, 95% CI 0.01 to 6.49; RD -0.03, 95% CI -0.11 to 0.05; 1 study, 69 participants; very low-certainty evidence). No neonate had surgical intervention (e.g. endoscopic balloon dilation, cricoid split, tracheostomy) for stridor or subglottic stenosis (1 study, 69 participants). Neonates randomized to cuffed ETT may be less likely to have a reintubation for any reason (RR 0.06, 95% CI 0.01 to 0.45; RD -0.39, 95% CI -0.57 to -0.21; number needed to treat for an additional beneficial outcome 3, 95% CI 2 to 5; 1 study, 69 participants; very low-certainty evidence). We are very uncertain about accidental extubation because the CIs of the RR were wide (RR 0.82, 95% CI 0.12 to 5.46; RD -0.01, 95% CI -0.12 to 0.10; 1 study, 69 participants; very low-certainty evidence). We are very uncertain about all-cause mortality during initial hospitalization because the CIs of the RR were extremely wide (RR 2.46, 95% CI 0.10 to 58.39; RD 0.03, 95% CI -0.05 to 0.10; 1 study, 69 participants; very low-certainty evidence). There is one ongoing trial. We classified two studies as awaiting classification because outcome data were not reported separately for newborns and older infants.

AUTHORS' CONCLUSIONS

Evidence for comparing cuffed versus uncuffed ETTs in neonates is limited by a small number of babies in a single RCT with possible bias. There is very low certainty evidence for all outcomes of this review. CIs of the estimate for postextubation stridor were wide. No neonate had clinical evidence for subglottic stenosis; however, endoscopy results were not available to assess the anatomy. Additional RCTs are necessary to evaluate the benefits and harms of cuffed ETTs (inflated and non-inflated) in the neonatal population. These studies must include neonates and be conducted both for short-term use (in the setting of the operating room) and chronic use (in the setting of chronic lung disease) of cuffed ETTs.

Performance of custom made videolaryngoscope for endotracheal intubation: A systematic review

Introduction

Videolaryngoscope is regarded as the standard of care for airway management in well-resourced setups however the technology is largely inaccessible and costly in middle and low-income countries. An improvised and cost-effective form of customized videolaryngoscope was proposed and studied for patient care in underprivileged areas however there were no distinct conclusions on its performances.

Method

The study follows PRISMA guidelines for systematic review and the protocol in International Prospective Register for Systematic Reviews. The primary aim was to assess the first attempt success of customized videolaryngoscope for endotracheal intubation. The secondary objective was to evaluate the number of attempts, laryngoscopic view in terms of Cormack Lehane score and Percentage of glottic opening, use of external laryngeal maneuver and stylet and, the airway injuries after the endotracheal intubation.

Result

Five studies were analyzed for risk of bias using the National Institute of Health Quality Assessment Tool for cross-sectional studies. Most of the studies had a poor to a fair level of evidence with only one study with a good level of evidence. Certainty of evidence was “very low” for all eligible studies when graded using the Grading of Recommendation, Assessment, Development and Evaluation approach for systematic review.

Conclusions

The certainty of the evidence regarding performance of custom-made videolaryngoscope compared to conventional laryngoscope was very low and the study was performed in small numbers with fair to the poor risk of bias. It was difficult to establish and do further analysis regarding whether the customized form of videolaryngoscope will improve the first attempt success rate for tracheal intubation, reduce the number of attempts, improve the laryngoscopic view, require fewer external aids and reduce the incidences of airway injury with the given low-grade evidence. Some properly conducted randomised clinical trials will be required to further analyze the outcome and make the strong recommendations.

Effect of Use of a Bougie vs Endotracheal Tube With Stylet on Successful Intubation on the First Attempt Among Critically Ill Patients Undergoing Tracheal Intubation: A Randomized Clinical Trial

IMPORTANCE

For critically ill adults undergoing emergency tracheal intubation, failure to intubate the trachea on the first attempt occurs in up to 20% of cases and is associated with severe hypoxemia and cardiac arrest. Whether using a tracheal tube introducer ("bougie") increases the likelihood of successful intubation compared with using an endotracheal tube with stylet remains uncertain.

OBJECTIVE

To determine the effect of use of a bougie vs an endotracheal tube with stylet on successful intubation on the first attempt.

DESIGN, SETTING, AND PARTICIPANTS

The Bougie or Stylet in Patients Undergoing Intubation Emergently (BOUGIE) trial was a multicenter, randomized clinical trial among 1102 critically ill adults undergoing tracheal intubation in 7 emergency departments and 8 intensive care units in the US between April 29, 2019, and February 14, 2021; the date of final follow-up was March 14, 2021.

INTERVENTIONS

Patients were randomly assigned to use of a bougie (n = 556) or use of an endotracheal tube with stylet (n = 546).

MAIN OUTCOMES AND MEASURES

The primary outcome was successful intubation on the first attempt. The secondary outcome was the incidence of severe hypoxemia, defined as a peripheral oxygen saturation less than 80%.

RESULTS

Among 1106 patients randomized, 1102 (99.6%) completed the trial and were included in the primary analysis (median age, 58 years; 41.0% women). Successful intubation on the first attempt occurred in 447 patients (80.4%) in the bougie group and 453 patients (83.0%) in the stylet group (absolute risk difference, -2.6 percentage points [95% CI, -7.3 to 2.2]; P = .27). A total of 58 patients (11.0%) in the bougie group experienced severe hypoxemia, compared with 46 patients (8.8%) in the stylet group (absolute risk difference, 2.2 percentage points [95% CI, -1.6 to 6.0]). Esophageal intubation occurred in 4 patients (0.7%) in the bougie group and 5 patients (0.9%) in the stylet group, pneumothorax was present after intubation in 14 patients (2.5%) in the bougie group and 15 patients (2.7%) in the stylet group, and injury to oral, glottic, or thoracic structures occurred in 0 patients in the bougie group and 3 patients (0.5%) in the stylet group.

CONCLUSIONS AND RELEVANCE

Among critically ill adults undergoing tracheal intubation, use of a bougie did not significantly increase the incidence of successful intubation on the first attempt compared with use of an endotracheal tube with stylet.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03928925

Intubation using VieScope vs. Video laryngoscopy in full personal protective equipment - a randomized, controlled simulation trial

BACKGROUND

VieScope is a new type of laryngoscope, with a straight, transparent and illuminated blade, allowing for direct line of sight towards the larynx. In addition, VieScope is disposed of after single patient use, which can avoid cross-contaminations of contagious material. This has gained importance especially when treating patients with highly contagious infectious diseases, such as during the SARS-CoV2 pandemic. In this context, VieScope has not been evaluated yet in a clinical study.

MATERIAL AND METHODS

This study compared intubation with VieScope to video-laryngoscopy (GlideScope) in normal and difficult airway in a standardized airway manikin in a randomized controlled simulation trial. Thirty-five medical specialists were asked to perform endotracheal intubation in full personal protective equipment (PPE). Primary endpoint was correct tube position. First-pass rate (i.e., success rate at the first attempt), time until intubation and time until first correct ventilation were registered as secondary endpoints.

RESULTS

For correct tracheal tube placement, there was no significant difference between VieScope and GlideScope in normal and difficult airway conditions. VieScope had over 91% fist-pass success rate in normal airway setting. VieScope had a comparable success rate to GlideScope in difficult airway, but had a significantly longer time until intubation and time until ventilation.

CONCLUSION

VieScope and GlideScope had high success rates in normal as well as in difficult airway. There was no unrecognized esophageal intubation in either group. Overall time for intubation was longer in the VieScope group, though in an acceptable range given in literature. Results from this simulation study suggest that VieScope may be an acceptable alternative for tracheal intubation in full PPE.

TRIAL REGISTRATION

The study was registered at the German Clinical Trials Register www.drks.de (Registration date: 09/11/2020; TrialID: DRKS00023406 ).

Application of a protective sleeve is associated with decreased occupational anxiety during endotracheal intubation: a randomized controlled trial

BACKGROUND

The high risk of cross-infection during tracheal intubation has caused excessive occupational anxiety for anaesthesiologists amid the novel coronavirus disease 2019 (COVID-19) pandemic. Currently, there is no effective way to attenuate their anxiety in clinical practice. We found that anaesthesiologist with better protective equipment might experience decreased levels of anxiety during intubation.

METHODS

In this study, 60 patients who underwent intubation and extubation in the operating room were enrolled, and then randomized 1:1 to either wear protective sleeves (protective sleeve group) or not (control group). Visual analogue scale (VAS) was used to measure the anxiety level of anaesthesiologists during intubation. The respiratory droplets of patients on the sleeve, and the anaesthesiologists' perception including the patient's oral malodour, exertion, satisfaction degree, waist discomfort and shoulder discomfort were recorded. The patients' anxiety, oppressed feelings and hypoxia and postoperative complications were all measured and recorded.

RESULTS

Compared with the control group, the anaesthesiologists in protective sleeve group achieved lower anxiety scores and better satisfaction degrees during the process of intubation and extubation (all P < 0.05). Respiratory droplets were observed only on the inner side, but not the external side, of the protective sleeves (P < 0.001). The incidence of the anaesthesiologists' perception of patients' oral malodour was significantly lower in the protective sleeve group (P = 0.02) and no patients developed hypoxemia or intubation-related complications in the protective sleeve group.

CONCLUSION

Using protective devices for intubation might eliminate droplet transmission from patients to anaesthesiologists, while also decreasing their anxiety in a controlled operating room environment.

TRIAL REGISTRATION

Chinese Clinical Trial. no. ChiCTR2000030705 . Registry at www.chictr.org.cn on 10/03/2020.

Predictors of post-extubation stridor in patients on mechanical ventilation: a prospective observational study

The cuff leak test (CLT) has been widely accepted as a simple and noninvasive method for predicting post-extubation stridor (PES). However, its accuracy and clinical impact remain uncertain. We aimed to evaluate the reliability of CLT and to assess the impact of pre-extubation variables on the incidence of PES. A prospective observational study was performed on adult critically ill patients who required mechanical ventilation for more than 24 h. Patients were extubated after the successful spontaneous breathing trial, and CLT was conducted before extubation. Of the 191 patients studied, 26 (13.6%) were deemed positive through CLT. PES developed in 19 patients (9.9%) and resulted in a higher reintubation rate (8.1% vs. 52.6%, p < 0.001) and longer intensive care unit stay (8 [4.5-14] vs. 12 [8-30.5] days, p = 0.01) than patients without PES. The incidence of PES and post-extubation outcomes were similar in patients with both positive and negative CLT results. Compared with patients without PES, patients with PES had longer durations of endotracheal intubation and required endotracheal suctioning more frequently during the 24-h period prior to extubation. After adjusting for confounding factors, frequent endotracheal suctioning more than 15 times per day was associated with an adjusted odds ratio of 2.97 (95% confidence interval, 1.01-8.77) for PES. In conclusion, frequent endotracheal suctioning before extubation was a significant PES predictor in critically ill patients. Further investigations of its impact on the incidence of PES and patient outcomes are warranted.

Changes in tapered endotracheal tube cuff pressure after changing position to hyperextension of neck: A randomized clinical trial

BACKGROUND

Endotracheal tube (ETT) with a tapered-shaped cuff had an improved sealing effect when compared to ETTs with a conventional cylindrical-shaped cuff. Positional change and neck movement typically displace an ETT and change the intracuff pressure. The aim of the current study was to compare the ETT cuff pressure in the TaperGuard ETT vs the conventional ETT after a change from the supine, neutral position to the extension of the neck and semi-Fowler position for thyroid surgery.

METHODS

This prospective, randomized clinical trial included 50 patients undergoing thyroidectomy. Patients were randomly allocated into one of the 2 groups: tracheal intubation with the TaperGuard ETT or with a conventional ETT. The ETT cuff was inflated with air and the ETT cuff pressure was set initially at 20 cmH2O using a calibrated cuff manometer. ETT cuff pressure and distance from carina to ETT tip were measured at supine and semi-Fowler positions with neck extension.

RESULTS

After the position change, the ETT tip migrated cephalad and cuff pressure increased in the majority of cases. ETT cuff pressure was significantly higher in the TaperGuard group than the conventional group (28.0 ± 6.6 cmH2O and 22.8 ± 4.5 cmH2O, respectively, P = .001). The degree of cephalad displacement of the ETT tip was comparable between the 2 groups (19.4 ± 6.31 mm in TaperGuard group and 21.9 ± 6.9 mm in conventional group, P = .12).

CONCLUSIONS

After the position change from supine to hyperextension of the neck, the ETT cuff pressure was higher in the TaperGuard ETT than in the conventional ETT, although the extent of displacement of the ETT was comparable between the 2 groups.

Comparison of intragastric pressure between endotracheal tube and supraglottic airway devices in laparoscopic hepatectomy: A randomized, controlled, non-inferiority study

BACKGROUND

Supraglottic airway (SGA) devices do not definitively protect the airway from regurgitation of gastric contents. Increased gastric pressure and long operation time are associated with development of complications such as aspiration pneumonia. The aim of this study was to compare intragastric pressure between second-generation SGA and endotracheal tube (ETT) devices during long-duration laparoscopic hepatectomy.

METHODS

A total of 66 patients was randomly assigned to 2 groups; 33 patients each in the ETT and SGA groups. Intragastric pressure was continuously measured via a gastric drainage tube with a three-way stopcock connected to the pressure monitoring device. Normal saline was added to the end of the gastric drainage tube at each operation time point.

RESULTS

Intragastric pressure during pneumoperitoneum was no different between the 2 groups (P = .146) or over time (P = .094). The mean (standard deviation [SD]) pH of the SGA tip measured after operation was 6.7 (0.4), and a pH <4 was not observed. Relative risk of postoperative complications was significantly higher in the ETT group relative to the SGA group (sore throat, 5.5; cough,13.0).

CONCLUSIONS

Use of SGA devices does not further increase intragastric pressure, even during prolonged upper abdominal laparoscopic surgery. Also, the frequency of postoperative sore throat and cough was significantly lower when the second-generation SGA device was used.

Tracheal suction at birth in non-vigorous neonates born through meconium-stained amniotic fluid

BACKGROUND

Neonates born through meconium-stained amniotic fluid (MSAF) are at risk of developing meconium aspiration syndrome (MAS). Neonates who are non-vigorous due to intrapartum asphyxia are at higher risk of developing MAS. Clearance of meconium from the airways below the vocal cords by tracheal suction before initiating other steps of resuscitation may reduce the risk of development of MAS. However, conducting tracheal suction may not only be ineffective, it may also delay effective resuscitation, thus prolonging and worsening the hypoxic-ischaemic insult.  OBJECTIVES: To evaluate the efficacy of tracheal suctioning at birth in preventing meconium aspiration syndrome and other complications among non-vigorous neonates born through meconium-stained amniotic fluid.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search Cochrane Central Register of Controlled Trials (CENTRAL 2020, Issue 11) in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R) (1946 to 25 November 2020) for randomised controlled trials (RCTs) and quasi-randomised trials. We also searched clinical trials databases and the reference lists of retrieved articles for RCTs and quasi-randomised trials (up to November 2020).

SELECTION CRITERIA

We included studies enrolling non-vigorous neonates born through MSAF, if the intervention being tested included tracheal suction at the time of birth with an intent to clear the trachea of meconium before regular breathing efforts began. Tracheal suction could be performed with an endotracheal tube or a wide-gauge suction catheter. Neonates in the control group should have been resuscitated at birth with no effort made to clear the trachea of meconium.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data, consulting with a third review author about any disagreements. We used standard Cochrane methodological procedures, including assessment of risk of bias for all studies. Our primary outcomes were: MAS; all-cause neonatal mortality; and incidence of hypoxic-ischaemic encephalopathy (HIE). Secondary outcomes included: need for mechanical ventilation; incidence of pulmonary air leaks; culture-positive sepsis; and persistent pulmonary hypertension. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included four studies (enrolling 581 neonates) in the review. All four studies were conducted in tertiary care hospitals in India. Three of the four studies included neonates born at and beyond term gestation, whereas one included neonates born at and beyond 34 weeks of gestation. Due to the nature of the intervention, it was not possible to blind the healthcare personnel conducting the intervention. Tracheal suction compared to no suction in non-vigorous neonates born through MSAF In non-vigorous infants, no differences were noted in the risks of MAS (RR 1.00, 95% CI 0.80 to 1.25; RD 0.00, 95% CI -0.07 to 0.08; 4 studies, 581 neonates) or all-cause neonatal mortality (RR 1.24, 95% CI 0.76 to 2.02; RD 0.02, 95% CI -0.03 to 0.07; 4 studies, 575 neonates) with or without tracheal suctioning. No differences were reported in the risk of any severity HIE (RR 1.05, 95% CI 0.68 to 1.63; 1 study, 175 neonates) or moderate to severe HIE (RR 0.68, 95% CI 0.43 to 1.09; 1 study, 152 neonates) among non-vigorous neonates born through MSAF. We are also uncertain as to the effect of tracheal suction on other outcomes such as incidence of mechanical ventilation (RR 0.99, 95% CI 0.68 to 1.44; RD 0.00, 95% CI -0.06 to 0.06; 4 studies, 581 neonates), pulmonary air leaks (RR 1.22, 95% CI 0.38 to 3.93; RD 0.00, 95% CI -0.02 to 0.03; 3 studies, 449 neonates), persistent pulmonary hypertension (RR 1.29, 95% CI 0.60 to 2.77; RD 0.02, 95% CI -0.03 to 0.06; 3 studies, 406 neonates) and culture-positive sepsis (RR 1.32, 95% CI 0.48 to 3.57; RD 0.01, 95% CI -0.03 to 0.05; 3 studies, 406 neonates). All reported outcomes were judged as providing very low certainty evidence.

AUTHORS' CONCLUSIONS

We are uncertain about the effect of tracheal suction on the incidence of MAS and its complications among non-vigorous neonates born through MSAF. One study awaits classification and could not be included in the review. More research from well-conducted large trials is needed to conclusively answer the review question.

Comparison of a Handheld Device vs Endotracheal Tube-Based Neuromonitoring for Recurrent Laryngeal Nerve Stimulation

OBJECTIVE

To measure the effect of thyroidectomy difficulty on intraoperative neuromonitoring false loss of signal (LOS) and to compare intraoperative endotracheal tube-based neuromonitoring (ETNM) and Checkpoint palpation-based direct stimulation (pDS) signals with postoperative laryngoscopy. We hypothesized that pDS has higher a positive predictive value for postdissection confirmation of recurrent laryngeal nerve function than ETNM and that this difference is accentuated with increasing thyroidectomy difficulty.

STUDY DESIGN

Prospective single-arm cross-sectional study comparing ETNM and pDS for patients undergoing hemi-, total, or completion thyroidectomy from July 2018 to March 2020.

SETTING

Single-surgeon series at a tertiary care hospital.

METHODS

Percentage concordance and positive and negative predictive values were measured. Each thyroidectomy was assigned a validated thyroidectomy difficulty score, and recorded recurrent laryngeal nerve signals were compared with postoperative vocal fold mobility.

RESULTS

Percentage concordance was 90.09%. Positive and negative predictive values were 0.19 (95% CI, 0.09-0.31) and 1.0 for ETNM and 0.59 (95% CI, 0.35-0.82) and 1.0 for pDS. The difference in positive predictive value was significant (0.40 [95% CI, 0.33-0.47], P < .001). False LOS rates for ETNM and pDS were 13.19% versus 3.30% (9.89% [95% CI, 1.80%-18.62%], P = .0155), 44.11% versus 0% (44.11% [95% CI, 25.80%-60.54%], P < .001), and 73.33% versus 13.33% (60% [95% CI, 24.76%-78.46%], P = .001) for the second through fourth thyroidectomy difficulty score quartiles, respectively. False LOS with ETNM was linearly correlated with increasing difficulty (R² = 0.97).

CONCLUSION

ETNM was subject to high rates of postdissection false LOS that increased with thyroidectomy difficulty score. pDS is a reliable alternative that has higher positive predictive value than ETNM, particularly in more challenging cases such as those with posteriorly fixed thyroid cancers and fibrotic glands.

EVIDENCE LEVEL

2.

Use of supraglottic airway devices under capnography monitoring during cardiopulmonary resuscitation: A systematic review

BACKGROUND

Bag-valve-mask ventilation is the most commonly applied method during cardiopulmonary resuscitation. Globally, advanced airway management with blind insertion devices such as supraglottic airway devices has been implemented for years by different emergency services. The efficiency of ventilation via such devices could be measured by capnography.

OBJECTIVE

The objective of this study was to determine whether capnography is useful in patients undergoing cardiopulmonary resuscitation and to assess the effectiveness of ventilation via supraglottic airway devices.

REVIEW METHODS USED

This is a systematic review written following the steps of Preferred Reporting Items for Systematic Review and Meta-analyses protocols.

DATA SOURCES

A bibliographic search was carried out from the following databases: EBSCOhost, Scopus, EMBASE, Virtual Health Library, PubMed, Cochrane Library, Spanish Medical Index, Spanish Bibliographic Index in Health Sciences, and Latin American and Caribbean Health Sciences Literature, from inception until September 2019.

REVIEW METHODS

Studies describing the use of capnography with supraglottic airway devices during cardiopulmonary resuscitation manoeuvres were selected and evaluated using the Critical Appraisal Skills Programme.

RESULTS

Twenty-four articles were identified by title and abstract: six were randomised clinical trials, 11 were nonrandomised clinical trials, six were descriptive prospective studies, and one was a descriptive retrospective study. Nine primary research articles were selected for synthesis. Only one provided objective values of capnography obtained with ventilation with these devices, correlating them with the results of resuscitation.

CONCLUSIONS

The evidence published so far is scarce, mostly from observational studies with high risk of bias in general. Although a degree of recommendation cannot be established, some results indicate that capnography has the potential to facilitate advanced clinical practice of ventilation with supraglottic airway devices during cardiopulmonary resuscitation.

Comparison of Glidescope Core, C-MAC Miller and conventional Miller laryngoscope for difficult airway management by anesthetists with limited and extensive experience in a simulated Pierre Robin sequence: A randomized crossover manikin study

BACKGROUND

Video laryngoscopy is an effective tool in the management of difficult pediatric airway. However, evidence to guide the choice of the most appropriate video laryngoscope (VL) for airway management in pediatric patients with Pierre Robin syndrome (PRS) is insufficient. Therefore, the aim of this study was to compare the efficacy of the Glidescope® Core™ with a hyperangulated blade, the C-MAC® with a nonangulated Miller blade (C-MAC® Miller) and a conventional Miller laryngoscope when used by anesthetists with limited and extensive experience in simulated Pierre Robin sequence.

METHODS

Forty-three anesthetists with limited experience and forty-three anesthetists with extensive experience participated in our randomized crossover manikin trial. Each performed endotracheal intubation with the Glidescope® Core™ with a hyperangulated blade, the C-MAC® with a Miller blade and the conventional Miller laryngoscope. "Time to intubate" was the primary endpoint. Secondary endpoints were "time to vocal cords", "time to ventilate", overall success rate, number of intubation attempts and optimization maneuvers, Cormack-Lehane score, severity of dental trauma and subjective impressions.

RESULTS

Both hyperangulated and nonangulated VLs provided superior intubation conditions. The Glidescope® Core™ enabled the best glottic view, caused the least dental trauma and significantly decreased the "time to vocal cords". However, the failure rate of intubation was 14% with the Glidescope® Core™, 4.7% with the Miller laryngoscope and only 2.3% with the C-MAC® Miller when used by anesthetists with extensive previous experience. In addition, the "time to intubate", the "time to ventilate" and the number of optimization maneuvers were significantly increased using the Glidescope® Core™. In the hands of anesthetists with limited previous experience, the failure rate was 11.6% with the Glidescope® Core™ and 7% with the Miller laryngoscope. Using the C-MAC® Miller, the overall success rate increased to 100%. No differences in the "time to intubate" or "time to ventilate" were observed.

CONCLUSIONS

The nonangulated C-MAC® Miller facilitated correct placement of the endotracheal tube and showed the highest overall success rate. Our results therefore suggest that the C-MAC® Miller could be beneficial and may contribute to increased safety in the airway management of infants with PRS when used by anesthetists with limited and extensive experience.

Endotracheal intubation of COVID-19 patients by paramedics using a box barrier: A randomized crossover manikin study

BACKGROUND

In the prehospital setting, endotracheal intubation (ETI) may be required to secure the coronavirus disease 2019 (COVID-19) patient airway. It has been suggested that the use of a protective barrier can reduce possible aerosol delivery from patients to clinicians during ETI. We sought to assess the performance of ETI by paramedics wearing personal protective equipment with and without the use of a box barrier.

METHODS

A randomized, crossover simulation study was performed in a simulation laboratory. Study participants were 18 paramedics actively working in the clinical environment. Participants' performance of ETI via direct laryngoscopy (DL) with and without the use of a box barrier was assessed. The sequence of intubation was randomized to either BoxDL-first or DL-first. The primary outcome was the success rate of ETI on first-attempt. The secondary and tertiary outcomes were ETI success rates on three attempts and total intubation time, respectively.

RESULTS

There were no differences between the DL group and the BoxDL group in one-attempt success rates (14/18 vs 12/18; P = 0.754), and in overall success rates (16/18 vs 14/18; P = 0.682). The mean (standard deviation) of the total intubation times for the DL group and the BoxDL group were 27.3 (19.7) seconds and 36.8 (26.2) seconds, respectively (P < 0.015).

CONCLUSIONS

The findings of this pilot study suggest that paramedics wearing personal protective equipment can successfully perform ETI using a barrier box, but the intubation time may be prolonged. The applicability of these findings to the care of COVID-19 patients remain to be investigated.

Comparison of polyurethane tracheal tube cuffs and conventional polyvinyl chloride tube cuff for prevention of ventilator-associated pneumonia: A systematic review with meta-analysis

BACKGROUND

The aim of this meta-analysis with trial sequential analysis (TSA) was to evaluate the effect of a polyurethane (PU) tracheal tube cuff on the prevention of ventilator-associated pneumonia (VAP).

METHODS

We performed a systematic search using the MEDLINE database through PubMed, Cochrane Central Register of Controlled Trial, SCOPUS, and Web of Science.Randomized controlled trials comparing the incidence of VAP and clinically relevant outcomes between PU cuff tubes and polyvinyl chloride (PVC) cuff tubes in adult patients. Two authors independently extracted study details, patient characteristics, and clinical outcomes such as incidence of VAP, bacterial colonization of tracheal aspirate, duration of mechanical ventilation, ICU stay, and ICU mortality.

RESULTS

From 309 studies identified as potentially eligible, six studies with 1226 patients were included in this meta-analysis. All studies compared the incidence of VAP between PU cuffs and PVC cuffs. Use of a PU cuff was not associated with a reduction in VAP incidence (RR = 0.68; 95% CI, 0.45-1.03) with significant statistical heterogeneity (I2 = 65%). The quality of evidence was "very low." According to the TSA, the actual sample size was only 15.8% of the target sample size, and the cumulative Z score did not cross the trial sequential monitoring boundary for benefit. No positive impact was reported for the other relevant outcomes for PU cuffs.

CONCLUSIONS

The use of a PU cuff for mechanical ventilation did not prevent VAP. Further trials with a low risk of bias need to be performed.

Ventilation strategies for front of neck airway rescue: an in silico study

BACKGROUND

During induction of general anaesthesia a 'cannot intubate, cannot oxygenate' (CICO) situation can arise, leading to severe hypoxaemia. Evidence is scarce to guide ventilation strategies for small-bore emergency front of neck airways that ensure effective oxygenation without risking lung damage and cardiovascular depression.

METHODS

Fifty virtual subjects were configured using a high-fidelity computational model of the cardiovascular and pulmonary systems. Each subject breathed 100% oxygen for 3 min and then became apnoeic, with an obstructed upper airway. When arterial haemoglobin oxygen saturation reached 40%, front of neck airway access was simulated with various configurations. We examined the effect of several ventilation strategies on re-oxygenation, pulmonary pressures, cardiovascular function, and oxygen delivery.

RESULTS

Re-oxygenation was achieved in all ventilation strategies. Smaller airway configurations led to dynamic hyperinflation for a wide range of ventilation strategies. This effect was absent in airways with larger internal diameter (≥3 mm). Intrapulmonary pressures increased quickly to supra-physiological values with the smallest airways, resulting in pronounced cardio-circulatory depression (cardiac output <3 L min^-1 and mean arterial pressure <60 mm Hg), impeding oxygen delivery (<600 ml min^-1). Limiting tidal volume (≤200 ml) and ventilatory frequency (≤8 bpm) for smaller diameter cannulas reduced dynamic hyperinflation and gas trapping, preventing cardiovascular depression.

CONCLUSIONS

Dynamic hyperinflation can be demonstrated for a wide range of front of neck airway cannulae when the upper airway is obstructed. When using small-bore cannulae in a CICO situation, ventilation strategies should be chosen that prevent gas trapping to prevent severe adverse events including cardio-circulatory depression.

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

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

Comparison of airway management without neuromuscular blockers in laparoscopic gynecological surgery

New generation supraglottic airway devices are suitable for airway management in many laparoscopic surgeries. In this study, we evaluated and compared the ventilation parameters of the laryngeal mask airway-supreme (LM-S) and endotracheal tube (ETT) when a neuromuscular blocker (NMB) agent was not used during laparoscopic gynecological surgery. The second outcome was based on the evaluation of the surgical view because it may affect the surgical procedure.This was a randomized study that enrolled 100 patients between 18 and 65 years old with an ASA I-II classification. Patients were divided into 2 groups: Group ETT and Group LM-S. Standard anesthesia and ventilation protocols were administered to patients in each group. Ventilation parameters [airway peak pressure (Ppeak), mean airway pressure (Pmean), total volume, and oropharyngeal leak pressure] were recorded before, after, and during peritoneal insufflation and before desufflation, as well as after the removal of the airway device. Perioperative surgical view quality and the adequacy of the pneumoperitoneum were also recorded.The data of 100 patients were included in the statistical analysis. The Ppeak values in Group ETT were significantly higher in the second minute after airway device insertion. The Ppeak and Pmean values in Group ETT were significantly higher before desufflation and after removal of the airway device. No significant differences were found between the groups in terms of adequacy of the pneumoperitoneum or quality of the surgical view.The results of this study showed that gynecological laparoscopies can be performed without using a NMB. Satisfactory conditions for ventilation and surgery can be achieved while sparing the use of muscle relaxants in both groups despite the Trendelenburg position and the pneumoperitoneum of the patients, which are typical for laparoscopic gynecological surgery. The results are of clinical significance because they show that the use of a muscle relaxant is unnecessary when supraglottic airways are used for these surgical procedures.

COVID-19 aerosol box as protection from droplet and aerosol contaminations in healthcare workers performing airway intubation: a randomised cross-over simulation study

BACKGROUND

Concerns over high transmission risk of SARS-CoV-2 have led to innovation and usage of an aerosol box to protect healthcare workers during airway intubation in patients with COVID-19. Its efficacy as a barrier protection in addition to the use of a standard personal protective equipment (PPE) is not fully known. We performed a simulated study to investigate the relationship between aerosol box usage during intubation and contaminations on healthcare workers pre-doffing and post-doffing of PPE.

METHODS

This was a randomised cross-over study conducted between 9 April to 5 May 2020 in the ED of University Malaya Medical Centre. Postgraduate Emergency Medicine trainees performed video laryngoscope-assisted intubation on an airway manikin with and without an aerosol box in a random order. Contamination was simulated by nebulised Glo Germ. Primary outcome was number of contaminated front and back body regions pre-doffing and post-doffing of PPE of the intubator and assistant. Secondary outcomes were intubation time, Cormack-Lehane score, number of intubation attempts and participants' feedback.

RESULTS

Thirty-six trainees completed the study interventions. The number of contaminated front and back body regions pre-doffing of PPE was significantly higher without the aerosol box (all p values<0.001). However, there was no significant difference in the number of contaminations post-doffing of PPE between using and not using the aerosol box, with a median contamination of zero. Intubation time was longer with the aerosol box (42.5 s vs 35.5 s, p<0.001). Cormack-Lehane scores were similar with and without the aerosol box. First-pass intubation success rate was 94.4% and 100% with and without the aerosol box, respectively. More participants reported reduced mobility and visibility when intubating with the aerosol box.

CONCLUSIONS

An aerosol box may significantly reduce exposure to contaminations but with increased intubation time and reduced operator's mobility and visibility. Furthermore, the difference in degree of contamination between using and not using an aerosol box could be offset by proper doffing of PPE.

Three-day tracheal intubation manikin training for novice doctors using Macintosh laryngoscope, McGRATH MAC videolaryngoscope and Pentax AirwayScope

BACKGROUND

We compared the intubation skills obtained by novice doctors following training using 3 instruments, the conventional Macintosh laryngoscope (Mac) and 2 types of indirect video-laryngoscopes (McGrathTM-MAC: McGrath (McG) and AirwayScope (AWS)), to determine the most appropriate instrument for novice doctors to acquire intubation skills, especially focusing on visual confirmation of vocal cords, during a 3-day intensive manikin training program.

METHODS

Fifteen novice doctors who did not have sufficient experience in endotracheal intubation (ETI) and consented to participate in this study were included. We used AirSim and AMT (Airway management Trainer) manikins. First, an experienced anesthesiologist instructed the trainees on using the 3 instruments for a few minutes. Then, after familiarizing themselves with each device for 10 minutes, the participants attempted ETI on the 2 manikins with the 3 devices used in random order. Intubations with each device were practiced and performed for 3 successive days. We assessed the percentage of glottic opening (POGO) score, successful intubation rate and tracheal intubation time for each participant, with each device, and on each day.

RESULTS

In the first manikin, AirSim, POGO scores in the McG and AWS groups were significantly higher than those in the Mac group on all 3 days (P < .0001). The number of intubation failures in the Mac group decreased from 2 cases on day 1, to 1 case on day 2 and zero cases on day 3. There were no failures in the McG and AWS groups on any of the days. With the second manikin, AMT, POGO scores in the Mac group were significantly lower than those in the McG and AWS groups on all 3 days. There were no intubation failures in the AWS group on all 3 days. In the Mac group, the number of intubation failures decreased from 3 on day 1, to 2 on day 2 and zero failures on day 3. In the McG group, there were only 3 failures on day 1.

CONCLUSION

The 2 types of indirect video-laryngoscopes (McGRATH and AirwayScope) were demonstrated to be suitable instruments for novice doctors to achieve higher POGO scores in a 3-day intensive ETI training.

Efficacy of Venner-PneuX endotracheal tube system for prevention of ventilator-associated pneumonia in intensive care units: A protocol for systematic review and meta-analysis

BACKGROUND

The pathogenic mechanism and prevention of ventilator-associated pneumonia (VAP) are substantially improved over the past several decades, but VAP remains frequently seen among the critical cases. The Venner-PneuX endotracheal tube system (VPXETS) has been proved to perform better than standard endotracheal tubes (SET) in the prevention of VAP in some studies. Therefore, this systematic review is aimed at evaluating the effectiveness of VPXETS in order to prevent VAP.

METHODS

Electronic databases, including PubMed, WANFANG, CENTRAL, CNKI, EMBASE, and CINAHL, are used to search relevant randomized controlled trials for evaluating the therapeutic effect of VPXETS on preventing VAP from January 2011 to December 2020. To be specific, related studies are selected, data are extracted, risk of bias is assessed, and meta-analysis is conducted in succession.

RESULTS

The present review aims to assess the therapeutic effect of VPXETS on preventing VAP in intensive care units (ICUs). Our outcome measures include the incidence and side reaction of VAP.

CONCLUSIONS

The present review assesses related studies regarding the therapeutic effect of VPXETS on preventing VAP at ICUs.

DISSEMINATION AND ETHICS

Our findings in this work are to be disseminated by means of peer-reviewed publication. No ethical approval is required in our review since it uses the published data. Moreover, anonymity is guaranteed during the data analysis process.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/6BERJ.

A Randomized Trial of Laryngeal Mask Airway in Neonatal Resuscitation

BACKGROUND

Face-mask ventilation is the most common resuscitation method for birth asphyxia. Ventilation with a cuffless laryngeal mask airway (LMA) has potential advantages over face-mask ventilation during neonatal resuscitation in low-income countries, but whether the use of an LMA reduces mortality and morbidity among neonates with asphyxia is unknown.

METHODS

In this phase 3, open-label, superiority trial in Uganda, we randomly assigned neonates who required positive-pressure ventilation to be treated by a midwife with an LMA or with face-mask ventilation. All the neonates had an estimated gestational age of at least 34 weeks, an estimated birth weight of at least 2000 g, or both. The primary outcome was a composite of death within 7 days or admission to the neonatal intensive care unit (NICU) with moderate-to-severe hypoxic-ischemic encephalopathy at day 1 to 5 during hospitalization.

RESULTS

Complete follow-up data were available for 99.2% of the neonates. A primary outcome event occurred in 154 of 563 neonates (27.4%) in the LMA group and 144 of 591 (24.4%) in the face-mask group (adjusted relative risk, 1.16; 95% confidence interval [CI], 0.90 to 1.51; P = 0.26). Death within 7 days occurred in 21.7% of the neonates in the LMA group and 18.4% of those in the face-mask group (adjusted relative risk, 1.21; 95% CI, 0.90 to 1.63), and admission to the NICU with moderate-to-severe hypoxic-ischemic encephalopathy at day 1 to 5 during hospitalization occurred in 11.2% and 10.1%, respectively (adjusted relative risk, 1.27; 95% CI, 0.84 to 1.93). Findings were materially unchanged in a sensitivity analysis in which neonates with missing data were counted as having had a primary outcome event in the LMA group and as not having had such an event in the face-mask group. The frequency of predefined intervention-related adverse events was similar in the two groups.

CONCLUSIONS

In neonates with asphyxia, the LMA was safe in the hands of midwives but was not superior to face-mask ventilation with respect to early neonatal death and moderate-to-severe hypoxic-ischemic encephalopathy. (Funded by the Research Council of Norway and the Center for Intervention Science in Maternal and Child Health; NeoSupra ClinicalTrials.gov number, NCT03133572.).

Use of the GlideScope does not lower the hemodynamic response to tracheal intubation more than the Macintosh laryngoscope: a systematic review and meta-analysis

BACKGROUND

It is presently unclear whether the hemodynamic response to intubation is less marked with indirect laryngoscopy using the GlideScope (GlideScope) than with direct laryngoscopy using the Macintosh laryngoscope. Thus, the aim of this study was to determine whether using the GlideScope lowers the hemodynamic response to tracheal intubation more than using the Macintosh laryngoscope.

METHODS

We performed a comprehensive literature search of electronic databases for clinical trials comparing hemodynamic response to tracheal intubation. The primary aim was to determine whether the heart rate (HR) and mean blood pressure (MBP) 60 s after tracheal intubation with the GlideScope were lower than after intubation with the Macintosh laryngoscope. We expressed pooled differences in HR and MBP between the devices as the weighted mean difference with 95% confidence interval and also performed trial sequential analysis (TSA). Second, we examined whether use of the GlideScope resulted in lower post-intubation hemodynamic responses at 120, 180, and 300 s compared with use of the Macintosh laryngoscope. For sensitivity analysis, we used a multivariate random effects model that accounted for within-study correlation of the longitudinal data.

RESULTS

The literature search identified 13 articles. HR and MBP at 60 seconds post-intubation was not significantly lower with the GlideScope than with the Macintosh (HR vs MBP: weighted mean difference = 0.22 vs 2.56; 95% confidence interval -3.43 to 3.88 vs -0.82 to 5.93; P = .90 vs 0.14; I = 77% vs 63%: Cochran Q, 52.7 vs 27.2). Use of the GlideScope was not associated with a significantly lower HR or MBP at 120, 180, or 300 s post-intubation. TSA indicated that the total sample size was over the futility boundary for HR and MBP. Sensitivity analysis indicated no significant association between use of the GlideScope and a lower HR or MBP at any measurement point.

CONCLUSIONS

Compared with the Macintosh laryngoscope, the GlideScope did not lower the hemodynamic response after tracheal intubation. Sensitivity analysis results supported this finding, and the results of TSA suggest that the total sample size exceeded the TSA monitoring boundary for HR and MBP.

Novel expandable architected breathing tube for improving airway securement in emergency care

Life-saving interventions utilize endotracheal intubation to secure a patient's airway, but performance of the clinical standard of care endotracheal tube (ETT) is inadequate. For instance, in the current COVID-19 crisis, patients can expect prolonged intubation. This protracted intubation may produce health complications such as tracheal stenosis, pneumonia, and necrosis of tracheal tissue, as current ETTs are not designed for extended use. In this work, we propose an improved ETT design that seeks to overcome these limitations by utilizing unique geometries which enable a novel expanding cylinder. The mechanism provides a better distribution of the contact forces between the ETT and the trachea, which should enhance patient tolerability. Results show that at full expansion, our new ETT exerts pressures in a silicone tracheal phantom well within the recommended standard of care. Also, preliminary manikin tests demonstrated that the new ETT can deliver similar performance in terms of air pressure and air volume when compared with the current gold standard ETT. The potential benefits of this new architected ETT are threefold, by limiting exposure of healthcare providers to patient pathogens through streamlining the intubation process, reducing downstream complications, and eliminating the need of multiple size ETT as one architected ETT fits all.

Learning curve and performance in simulated difficult airway for the novel C-MAC® video-stylet and C-MAC® Macintosh video laryngoscope: A prospective randomized manikin trial

Difficult airways can be managed with a range of devices, with video laryngoscopes (VLs) being the most common. The C-MAC® Video-Stylet (VS; Karl-Storz Germany), a hybrid between a flexible and a rigid intubation endoscope, has been recently introduced. The aim of this study is to investigate the performance of the VS compared to a VL (C-MAC Macintosh blade, Karl-Storz Germany) with regards to the learning curve for each device and its ability to manage a simulated difficult airway manikin. This is a single-center, prospective, randomized, crossover study involving twenty-one anesthesia residents performing intubations on a Bill 1™ (VBM, Germany) airway manikin model. After a standardized introduction, six randomized attempts with VL and VS were performed on the manikin. This was followed by intubation in a simulated difficult airway (cervical collar and inflated tongue) with both devices in a randomized fashion. The primary end-point of this study was the total time to intubation. All continuous variables were expressed as the median [interquartile range] and analyzed using the Mann-Whitney U test. A 2-way ANOVA with Bonferroni's post hoc test was used to compare both devices at each trial. All reported p values are two sided. The median total time to intubation on a simulated difficult airway was faster with the VS compared to VL (17 [13.5-25] sec vs 23 [18.5-26.5] sec, respectively; 95% CI; P = 0.031). Additionally, on a normal airway manikin, the VS has a comparable learning curve to the VL. In this manikin-based study, the novel VS was comparable to the VL in terms of learning curve in a normal airway. In a simulated difficult airway, the total time to intubation, though likely not clinically relevant, was faster with the VS to the VL. However, given the above findings, this study justifies further human clinical trials with the VS to see if similar benefits-faster time to intubation and similar learning curve to VL-are replicated clinically.

Airway Rupture Caused by Double-Lumen Tubes: A Review of 187 Cases

The double-lumen tubes (DLTs) are the most widely used devices to provide perioperative lung isolation. Airway rupture is a rare but life-threatening complication of DLTs. The primary aim of this review was to collect all cases reported in the literature about airway rupture caused by DLTs and to describe the reported possible contributors, diagnosis, treatment, and outcomes of this complication. Another aim of this review was to assess the possible factors associated with mortality after airway rupture by DLTs. A comprehensive literature search for all cases of airway rupture caused by DLTs was performed in the PubMed, EMBASE, Ovid, Wanfang Database, and CNKI. The extracted data included age, sex, height, weight, type of operation, type and size of DLT, site of airway rupture, possible contributors, clinical presentation, diagnosis timing, treatment, and outcome. We included 105 single case reports and 22 case series with a total number of 187 patients. Most of the ruptures were in the trachea (n = 98, 52.4%) and left main bronchus (n = 70, 37.4%). The common possible contributors include use of a stylet, cuff overdistention, multiple attempts to adjust the position of a DLT, difficult intubation, and use of an oversized DLT. Most of the airway ruptures were diagnosed intraoperatively (n = 138, 82.7%). Pneumomediastinum, air leakage, hypoxemia, and subcutaneous emphysema were the common clinical manifestations. Most patients were treated with surgical repair (n = 147, 78.6%). The mortality of the patients with airway rupture by DLTs was 8.8%. Age, sex, site of rupture, diagnosis timing, and method of treatment were not found to be associated with mortality.

[Effectiveness of simplified predictive intubation difficulty score and thyromental height in head and neck surgeries: an observational study]

BACKGROUND AND OBJECTIVES

In this study, we aimed to investigate the predictive value of different airway assessment tools, including parts of the Simplified Predictive Intubation Difficulty Score (SPIDS), the SPIDS itself and the Thyromental Height Test (TMHT), in intubations defined as difficult by the Intubation Difficulty Score (IDS) in a group of patients who have head and neck pathologies.

METHODS

One hundred fifty-three patients who underwent head and neck surgeries were included in the study. The Modified Mallampati Test (MMT) result, Thyromental Distance (TMD), Ratio of the Height/Thyromental Distance (RHTMD), TMHT, maximum range of head and neck motion, and mouth opening were measured. The SPIDSs were calculated, and the IDSs were determined.

RESULTS

A total of 25.4% of the patients had difficult intubations. SPIDS scores > 10 had 86.27% sensitivity, 71.57% specificity and 91.2% Negative Predictive Value (NPV). The results of the Receiver Operating Curve (ROC) analysis for the airway screening tests and SPIDS revealed that the SPIDS had the highest area under the curve; however, it was statistically similar to other tests, except for the MMT.

CONCLUSIONS

The current study demonstrates the practical use of the SPIDS in predicting intubation difficulty in patients with head and neck pathologies. The performance of the SPIDS in predicting airway difficulty was found to be as efficient as those of the other tests evaluated in this study. The SPIDS may be considered a comprehensive, detailed tool for predicting airway difficulty.

Comparison of Supraglottic Airway Devices With Endotracheal Intubation in Low-Risk Patients for Cesarean Delivery: Systematic Review and Meta-analysis

BACKGROUND

The safety and adverse event rate of supraglottic airway (SGA) devices for cesarean delivery (CD) is poorly characterized. The primary aims of this review were to determine whether the first-pass success was higher and time to insertion for SGA was faster than endotracheal intubation for elective CD. The secondary aim was to determine the airway-related adverse event rate associated with SGA use compared to endotracheal intubation in elective CD under general anesthesia (GA).

METHODS

Six databases were systematically searched until September 2019. Included studies reported on the use of SGA in comparison to endotracheal tube intubation. A comparative meta-analysis between SGA and endotracheal intubation was performed using RevMan 5.3 software. Dichotomous outcomes were reported using an odds ratio (OR) with 95% confidence interval (CI). The results for continuous outcomes were reported using a weighted mean difference (WMD) with 95% CI.

RESULTS

Fourteen studies with 2236 patients compared SGA and endotracheal intubation. Overall, there was no statistically significant difference in first-attempt success rate (OR = 1.92; 95% CI, 0.85-4.32; I = 0%; P = .44). There was no clinically significant difference in time to insertion (WMD = -15.80 seconds; 95% CI, -25.30 to -6.31 seconds; I= 100%; P = .001). Similarly, there was no difference in any adverse event rate except sore throat which was reduced with the use of an SGA (OR = 0.16; 95% CI, 0.08-0.32; I= 53%; P < .001).

CONCLUSIONS

Despite the reasonable insertion success rate and safety profile of SGAs demonstrated in this meta-analysis, the analysis remains underpowered and therefore inconclusive. At present, further studies are required before the use of an SGA as the first-line airway for an elective CD can be recommended.

Supraglottic airway devices for pediatric airway management in the emergency department

Endotracheal intubation can be difficult in the emergent situation, and it is important to have an appropriate backup strategy. Supraglottic airway devices have provided an alternative method for pediatric airway management that is relatively easy to learn, with a high success rate. This issue reviews the use of supraglottic airway devices in pediatric patients including common devices, indications and techniques for placement, and complications associated with their use. The use of supraglottic airway devices in the patient with a difficult airway is also discussed.

Changing the view: Video versus direct laryngoscopy for intubation in the pediatric emergency department

The aim of this study was to compare the success of first-attempt tracheal intubation in pediatric patients >1-year old performed using video versus direct laryngoscopy and compare the frequency of tracheal intubation-associated events and desaturation among these patients.Prospective observational cohort study conducted in an Academic pediatric tertiary emergency department. We compared 50 children intubated with Mcgrath Mac video laryngoscope (VL group) and an historical series of 141 children intubated with direct laryngoscopy (DL group). All patients were aged 1 to 18 years.The first attempt success rates were 68% (34/50) and 37.6% (53/141) in the VL and DL groups (P < .01), respectively. There was a lower proportion of tracheal intubation-associated events in the VL group (VL, 31.3% [15/50] vs DL, 67.8% [97/141]; P < .01) and no significant differences in desaturation (VL, 35% [14/50] vs DL 51.8% [72/141]; P = .06). The median number of attempts was 1 (range, 1-5) for the VL group and 2 (range, 1-8) for the DL group (P < .01). Multivariate logistic regression showed that video laryngoscope use was associated with higher chances of first-attempt intubation with an odds ratio of 4.5 (95% confidence interval, 1.9-10.4, P < 0.01).Compared with direct laryngoscopy, VL was associated with higher success rates of first-attempt tracheal intubations and lower rates of tracheal intubation-associated events.

Laryngeal tubes and laryngeal mask devices for supraglottic airway management in out-of-hospital emergency care: a systematic review

Various supraglottic devices are currently available for airway management and are used widely in emergency situations because they are easy to position. We undertook a systematic review of the literature comparing laryngeal tubes and various laryngeal mask airway devices (LMAs) to determine which ones can be used most efficiently in emergencies. Nine databases were searched, as follows: Cochrane Library Plus, MEDLINE, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Dialnet, Global Health, Nursing & Allied Health Database, CUIDEN, the Web of Science, and ScienceDirect. We collected studies published between 2014 and 2019 in Spanish, English, French, and Portuguese that compared laryngeal tubes to LMAs of different types for supraglottic airway management. Eighteen studies were selected for analysis after critical reading. Significant differences were not seen between tubes and LMAs with respect to most variables, but in certain contexts the oropharyngeal seal and speed of insertion were superior with laryngeal tubes; however, when fiberoptic bronchoscopes were then inserted the view of the glottis was poor. The different contexts in which these devices are used and the scarcity of studies comparing laryngeal tubes to LMAs does not allow us to identify clear differences among them with respect to efficiency. However, tubes seem to offer poorer visibility of the glottis according to evaluation with fiberoptic scopes, a factor to bear in mind if tracheal intubation, which is considered the gold standard, might become necessary.

The effect of laryngoscope types on hemodynamic response and optic nerve sheath diameter. McCoy, Macintosh, and C-MAC video-laryngoscope

OBJECTIVES

This study aims to investigate the effect of McCoy, Macintosh laryngoscope, and C-MAC video-laryngoscopes on optic nerve sheath diameter (ONSD) and hemodynamic responses to laryngoscopy and intubation.

METHODS

This prospective randomized study was conducted in Zonguldak Bülent Ecevit University Hospital, Zonguldak, Turkey, between July 2019 and January 2020. Informed written consent was obtained from all patients. Patients with previous intracranial/ocular surgery or glaucoma were excluded from the study. The patients were randomized to use McCoy, Macintosh, and C-MAC (30 per group). Intubations were performed by the same person. Mean arterial pressure, heart rate (HR), and ONSD were recorded before the induction and repeated in 1, 3, 5, and 10 minutes after the intubation.

RESULTS

The effects of laryngoscopy and intubation on hemodynamic responses and ONSD were similar between groups (p greater than 0.05). While the comparison within groups showed ONSD increase in McCoy group and HR and ONSD increase in the Macintosh group compared to baseline 1 min after the intubation, no change was observed in hemodynamic responses and ONSD measurements in the C-MAC® group (p greater than 0.05).

CONCLUSIONS

In this study, there was no significant difference between the groups in terms of ONSD and hemodynamic responses to laryngoscopy and intubation. It was observed that there were no significant changes in ONSD values just in C-MAC® video-laryngoscope group. Therefore, intubations with C-MAC® video-laryngoscope are thought to be more appropriate for patients with an increase in intracranial pressure.