Normal Airway Research Articles

Recent Advances in Videolaryngoscopy for One-Lung Ventilation in Thoracic Anesthesia: A Narrative Review.

Since their advent, videolaryngoscopes have played an important role in various types of airway management. Lung isolation techniques are often required for thoracic surgery to achieve one-lung ventilation with a double-lumen tube (DLT) or bronchial blocker (BB). In the case of difficult airways, one-lung ventilation is extremely challenging. The purpose of this review is to identify the roles of videolaryngoscopes in thoracic airway management, including normal and difficult airways. Extensive literature related to videolaryngoscopy and one-lung ventilation was analyzed. We summarized videolaryngoscope-guided DLT intubation techniques and discussed the roles of videolaryngoscopy in DLT intubation in normal airways by comparison with direct laryngoscopy. The different types of videolaryngoscopes for DLT intubation are also compared. In addition, we highlighted several strategies to achieve one-lung ventilation in difficult airways using videolaryngoscopes. A non-channeled or channeled videolaryngoscope is suitable for DLT intubation. It can improve glottis exposure and increase the success rate at the first attempt, but it has no advantage in saving intubation time and increases the incidence of DLT mispositioning. Thus, it is not considered as the first choice for patients with anticipated normal airways. Current evidence did not indicate the superiority of any videolaryngoscope to another for DLT intubation. The choice of videolaryngoscope is based on individual experience, preference, and availability. For patients with difficult airways, videolaryngoscope-guided DLT intubation is a primary and effective method. In case of failure, videolaryngoscope-guided single-lumen tube (SLT) intubation can often be achieved or combined with the aid of fibreoptic bronchoscopy. Placement of a DLT over an airway exchange catheter, inserting a BB via an SLT, or capnothorax can be selected for lung isolation.

A Study to Evaluate Changes in Modified Mallampati Class in Patients Undergoing Spine Surgery in Prone Position.

Background: Perioperative airway changes due to anesthesia and surgery could change a normal airway at induction to a risky airway at extubation.Objectives: The objective is to evaluate primarily the degree of airway changes, as quantified by the modified Mallampati (MMP) class, after spine surgery in the prone position. Secondary to assess the time required for these changes to revert back to the preoperative state and their correlation with other demographic and surgical variables.Methods: The present prospective observational study was conducted in a tertiary care hospital after ethical approval and trial registration. Fifty ASA I and II patients aged 18-65 years of both sex and undergoing spine surgery in prone positions were included. Supine MMP grade was observed preoperatively and at one, two, four, 24, and 48 hours postoperatively.Statistical analysis: IBM SPSS version 22 (IBM Corp, Armonk, NY) was used.Mean values were compared using paired t-tests and medians by the Wilcoxon test. The Spearman correlation was used to assess a relationship. The time for recovery was analyzed by Kaplan-Meir analysis.Results: An increase in MMP grade was observed at one hour postoperatively in 46 (92%) patients. Changes reverted back in 45 (98%) patients by 24 hours postoperatively. A weak positive correlation with age, weight, body mass index, duration of surgery, perioperative drop in hemoglobin, and a moderate positive correlation with fluid administered and estimated blood loss was recorded.Conclusions: An increase in postoperative MMP occurs in the majority of patients undergoing prone position spine surgery which may persist up to 48 hours. So, more vigilance and caution are warranted should reintubation be needed postoperatively.

Integrin/TGF-β1 Inhibitor GLPG-0187 Blocks SARS-CoV-2 Delta and Omicron Pseudovirus Infection of Airway Epithelial Cells In Vitro, Which Could Attenuate Disease Severity.

As COVID-19 continues to pose major risk for vulnerable populations, including the elderly, immunocompromised, patients with cancer, and those with contraindications to vaccination, novel treatment strategies are urgently needed. SARS-CoV-2 infects target cells via RGD-binding integrins, either independently or as a co-receptor with surface receptor angiotensin-converting enzyme 2 (ACE2). We used pan-integrin inhibitor GLPG-0187 to demonstrate the blockade of SARS-CoV-2 pseudovirus infection of target cells. Omicron pseudovirus infected normal human small airway epithelial (HSAE) cells significantly less than D614G or Delta variant pseudovirus, and GLPG-0187 effectively blocked SARS-CoV-2 pseudovirus infection in a dose-dependent manner across multiple viral variants. GLPG-0187 inhibited Omicron and Delta pseudovirus infection of HSAE cells more significantly than other variants. Pre-treatment of HSAE cells with MEK inhibitor (MEKi) VS-6766 enhanced the inhibition of pseudovirus infection by GLPG-0187. Because integrins activate transforming growth factor beta (TGF-β) signaling, we compared the plasma levels of active and total TGF-β in COVID-19+ patients. The plasma TGF-β1 levels correlated with age, race, and number of medications upon presentation with COVID-19, but not with sex. Total plasma TGF-β1 levels correlated with activated TGF-β1 levels. Moreover, the inhibition of integrin signaling prevents SARS-CoV-2 Delta and Omicron pseudovirus infectivity, and it may mitigate COVID-19 severity through decreased TGF-β1 activation. This therapeutic strategy may be further explored through clinical testing in vulnerable and unvaccinated populations.

Inspiration After Posterior Pharyngeal Flap Palatoplasty: A Preliminary Study Using Computational Fluid Dynamic Analysis.

Posterior pharyngeal flap palatoplasty (PPF) is one of the most commonly used surgical procedures to correct speech, especially for patients suffering from velopharyngeal insufficiency (VPI). During PPF, surgeons use the catheter to control the lateral velopharyngeal port on each side. Airway obstruction and sleep apnea are common after PPF. To understand the air dynamics of the upper airway after PPF, we used computational fluid dynamics (CFD) to demonstrate the airflow. In our previous study, we have revealed the expiration process of the upper airway after PPF and shown the features of how PPF successfully restores the oral pressure for speech. In this study, we focus on examining the inspiration process. Normal airway structures were included. For the normal velopharyngeal structure, one cylinder was applied to each model. For recapitulating the velopharyngeal structure after PPF, two cylinders were used in each model. The ports for borderline/inadequate closure, which can help the oral cavity get the required pressure, were chosen for this study. A real-time CFD simulation was used to capture the airflow through the ports. We found that the airflow dynamics of the upper airway’s inspiration were dependent on the velopharyngeal structure. Although the airflow patterns were similar, the velocities between one-port and two-port structures were different, which explained why patients after PPF breathed harder than before and suggested that the one-port structure might be a better choice for secondary VPI reconstruction based on the CFD analyses.

Discovery of a Fungal Metabolite as a Novel TMEM16a Inhibitor in Human Airway Epithelial Cells

Transmembrane protein 16a (TMEM16a) is a Ca2+‐activated Cl‐ channel (CaCC) that expresses in various epithelia. Inhibition of TMEM16a has been reported as a potential strategy for attenuating severity and progression of asthma. The main objective of this study is to discover a novel TMEM16a inhibitor and mechanisms of its action. By screening, we found that N9, a fungal metabolite, inhibited UTP‐activated TMEM16a Cl‐ current in basolaterally permeabilized Calu‐3 cell monolayers with an IC50 of ~ 0.8 µM and maximal inhibitory effect being observed at 10 µM. Indeed, N9 had no cytotoxic effect and did not disrupt airway epithelial barrier function, suggesting that inhibitory effect of N9 on TMEM16a was not due to the disturbance of normal airway epithelial function. Electrophysiological analyses indicated that N9 suppressed both ionomycin‐ and thapsigargin‐activated TMEM16a Cl‐ current. In addition, N9 had no effect on elevated intracellular Ca2+ level induced by UTP and thapsigargin, suggesting that N9 reduced TMEM16a Cl‐ current in human airway epithelial cell monolayers in a Ca2+‐independent mechanism. Of particular importance, N9 also significantly suppressed TMEM16a‐mediated Cl‐ current induced by Eact, a direct activator of TMEM16a, indicating that N9 exerts a novel class of TMEM16a inhibitor in human airway epithelial cell monolayers. Hence, this study may lead to identification of a novel class of anti‐asthmatic drug from fungal metabolites.

Initial clinical experience of the MedAn videolaryngoscope with the Nishikawa blade

BackgroundThe MedAn videolaryngoscope with the Nishikawa blade has been designed to make videolaryngoscopy and tracheal intubation safer and more successful. AimWe aimed to preliminarily evaluate the performance of this new videolaryngoscope system for routine tracheal intubation at a teaching hospital. MethodsA total of 243 patients with apparently normal airways scheduled for elective surgery under general anesthesia were randomly assigned to the consultant or trainee group according to the actual operation schedule. Video clips of videolaryngoscopic intubation were recorded to analyze the relevant parameters. The primary outcome was the first-attempt intubation success rate. The secondary outcomes included the total time to successful intubation (laryngoscopy and intubation times) on the first attempt and recorded soft tissue injury. ResultsThe first-attempt intubation success rate was 98.8% (240/243). The median total time to intubation on the first attempt was 26.0 s, and it was longer in the trainee group than in the consultant group (median, 28.0 vs. 23.0 s, p < 0.001). Soft tissue injury was not observed. ConclusionThe MedAn videolaryngoscope with the Nishikawa blade can provide an excellent laryngeal view and sufficient intubation pathway for safe, easy, and effective intubation in patients with apparently normal airways.

Endothelial Cell Injury and Activation in a Murine Model of Left Lung Transplantation

<h3>Purpose</h3> Endothelial cells are the first non-self-barrier encountered by the recipient's immune system after allograft transplantation and thus are involved early during alloimmune response. Our goal was to study processes of endothelial cell injury/activation in a mouse model of lung transplantation. <h3>Methods</h3> Mouse orthotopic left lung transplantation was performed in isografts (C57BL/6 to C57BL/6) and allografts (Balbc to C57BL/6), both received daily immunosuppression (10 mg/kg cyclosporin A and 1.6 mg/kg methylprednisolone) and were serially sacrificed at day 1, 7 and 35 post-transplant (n=6/timepoint/group). Left transplanted lungs were made into single cell suspension and absolute cell numbers were quantified by flow cytometry for CD31+ endothelial cells, CD45+ leukocytes and MHCI/II, VCAM-1 and ICAM-1 for cell activation. One additional allograft and isograft were scanned with high resolution (HR) <i>ex vivo</i> microCT (µCT) to visualize airways and blood vessels at day 70 post transplantation. <h3>Results</h3> Endothelial cell numbers decreased from day 1 until day 7 (p=0.03) in allografts and recovered slightly at day 35. While in isografts, endothelial cells seemed to increase non-significantly over time. In contrast, leukocytes significantly increased at day 7 in allografts versus day 1 (p=0.036) and isografts at day 7 (p=0.003). Leukocytes remained stable in isografts over time (p=0.3). Mean fluorescence intensity (MFI) was increased for MHC I/II and VCAM-1 (p=0.003; p<0.0001; p=0.04) on endothelial cells, the MFI of MHC I/II and ICAM-1 on leukocytes was increased in allografts versus isografts (p=0.0002; p=0.006; p=0.002). HR µCT showed normal airway morphology while lumen of arteries and veins was narrowed in allograft compared to isograft. Arterioles and venules were occluded in allograft. <h3>Conclusion</h3> Destruction of endothelial cells may represent the very first onset of alloimmune response post lung transplantation and warrant further investigations towards diagnostic and therapeutic approaches.

Mechanisms Involved in the Stimulatory and Inhibitory Effects of 5-Hydroxytryptamine on Vagal Mechanosensitive Afferents in Rat Lung.

Mechanosensitive vagal afferents in the lung, rapidly and slowly adapting receptors (RARs and SARs, respectively), play an important role in eliciting the reflexes that regulate the normal airway function. A profound bronchoconstrictive effect of 5-hydroxytryptamine (5-HT) has been extensively reported in various animal species, but its influence on the SAR and RAR activity is not known. This study investigated the effect of 5-HT on these receptors, and the possible mechanisms involved. Single-fiber activities of these afferents were measured in anesthetized, open-chest, and mechanically ventilated rats. Our results showed that intravenous injection of 5-HT evoked a consistent and pronounced stimulation of phasic RARs. In contrast, 5-HT generated an inconsistent and paradoxical action on SARs: no effect in 29% (5 of 17) of the SARs; stimulation in 35% (6 of 17); and inhibition in the remainder. These responses of both RARs and SARs to 5-HT were reproducible and dose-dependent. After the injection of a high dose of 5-HT (16 μg/kg), the receptor responses slowly reached a peak (after ∼8 s) and returned toward the baseline in ∼20 s, accompanied by a consistent increase in total pulmonary resistance and a decrease in dynamic lung compliance in a temporal pattern very similar to the increased receptor activity. When these changes in lung mechanics induced by 5-HT were prevented by pretreatment with salbutamol, a β2 adrenergic receptor agonist, the delayed responses of both RARs and SARs to 5-HT were also abolished, except that the immediate stimulatory effect on a subset of RARs, the silent RARs, was not affected. In conclusion, 5-HT generated a delayed stimulatory effect on RARs and a paradoxical effect on SARs, which resulted primarily from the 5-HT-induced changes in mechanical properties of the lung.

Aiding Airway Obstruction Diagnosis With Computational Fluid Dynamics and Convolutional Neural Network: A New Perspective and Numerical Case Study

AbstractIt is challenging to locate small-airway obstructions induced by chronic obstructive pulmonary disease (COPD) directly from visualization using available medical imaging techniques. Accordingly, this study proposes an innovative and noninvasive diagnostic method to detect obstruction locations using computational fluid dynamics (CFD) and convolutional neural network (CNN). Specifically, expiratory airflow velocity contours were obtained from CFD simulations in a subject-specific 3D tracheobronchial tree. One case representing normal airways and 990 cases associated with different obstruction sites were investigated using CFD. The expiratory airflow velocity contours at a selected cross section in the trachea were labeled and stored as the database for training and testing two CNN models, i.e., ResNet50 and YOLOv4. Gradient-weighted class activation mapping (Grad-CAM) and the Pearson correlation coefficient were employed and calculated to classify small-airway obstruction locations and pulmonary airflow pattern shifts and highlight the highly correlated regions in the contours for locating the obstruction sites. Results indicate that the airflow velocity pattern shifts are difficult to directly visualize based on the comparisons of CFD velocity contours. CNN results show strong relevance exists between the locations of the obstruction and the expiratory airflow velocity contours. The two CNN-based models are both capable of classifying the left lung, right lung, and both lungs obstructions well using the CFD simulated airflow contour images with total accuracy higher than 95.07%. The two automatic classification algorithms are highly transformative to clinical practice for early diagnosis of obstruction locations in the lung using the expiratory airflow velocity distributions, which could be imaged using hyperpolarized magnetic resonance imaging.

Comparison of two external manoeuvres with the conventional technique on glottic visualisation using a C-MAC® videolaryngoscope in children for elective surgery

Background and Aims:Glottic visualization is a pre-requisite for successful intubation. We compared the effect of backward upward rightward pressure (BURP) and jaw thrust manoeuvres with the conventional technique on glottic visualisation using a C-MAC® videolaryngoscope in children of 3 to 10 years.Methods:Ninety children of either gender of 3 to 10 years with normal airways and of the American Society of Anesthesiologists grade I or II for elective surgery under general anaesthesia with endotracheal intubation using a C-MAC® videolaryngoscope were enroled. Glottic views with the conventional technique (C), BURP (B), and jaw thrust (J) manoeuvres in three groups were assessed by modified Cormack Lehane grade (MCL) grade, percentage of glottic view (POGO) score, and a new two-dimensional metric – approximate glottic opening area in pixels squared. Approximate glottic opening area calculations were performed using tool pencil in horos medical imaging software.Results:Jaw thrust had statistically significant superiority over the conventional technique and BURP on glottic visualisation (a p value of C vs J < 0.0001 and B vs J < 0.05 for all the three parameters). BURP was comparable to the conventional technique in MCL grade and POGO score (a p value of C vs B > 0.05) but was superior to the conventional technique in glottic area (a p value of C vs B = 0.013).Conclusion:Jaw thrust enhanced glottic visualisation by maximising all the glottic view parameters as compared to the BURP manoeuvre and the conventional technique and should be considered the primary manoeuvre to aid intubation in children.Glottic Area (pixels squared)C (n=90)B (n=90)J (n=90)Total P C vs BC vs JB vs JMean±SD3969.64±2180.884657.19±1994.875508.12±2036.954711.65±2158.81<.00010.013<.00010.006Median (25th-75th percentile)3469.79 (2356.025-5193.743)4452.7 (3238.408-5482.152)5332.83 (4157.038-6904.62)4419.82 (3065.835-5821.836)Range639.02-9996.47638.23-9467.261603.95-9848638.23-9996.47

Smith’s Anesthesia for Infants and Children, 10th Edition

Smith’s Anesthesia for Infants and Children, 10th Edition

Comparisons of Videolaryngoscopes for Intubation Undergoing General Anesthesia: Systematic Review and Network Meta-Analysis of Randomized Controlled Trials.

Background: The efficacy and safety of videolaryngoscopes (VLs) for tracheal intubation is still conflicting and changeable according to airway circumstances. This study aimed to compare the efficacy and safety of several VLs in patients undergoing general anesthesia. Methods: Medline, EMBASE, and the Cochrane Library were searched until 13 January 2020. The following VLs were evaluated compared to the Macintosh laryngoscope (MCL) by network meta-analysis for randomized controlled trials (RCTs): Airtraq, Airwayscope, C-MAC, C-MAC D-blade (CMD), GlideScope, King Vision, and McGrath. Outcome measures were the success and time (speed) of intubation, glottic view, and sore throat (safety). Results: A total of 9315 patients in 96 RCTs were included. The highest-ranked VLs for first-pass intubation success were CMD (90.6 % in all airway; 92.7% in difficult airway) and King Vision (92% in normal airway). In the rank analysis for secondary outcomes, the following VLs showed the highest efficacy or safety: Airtraq (safety), Airwayscope (speed and view), C-MAC (speed), CMD (safety), and McGrath (view). These VLs, except McGrath, were more effective or safer than MCL in moderate evidence level, whereas there was low certainty of evidence in the intercomparisons of VLs. Conclusions: CMD and King Vision could be relatively successful than MCL and other VLs for tracheal intubation under general anesthesia. The comparisons of intubation success between VLs and MCL showed moderate certainty of evidence level, whereas the intercomparisons of VLs showed low certainty evidence.

Dental Strain on Maxillary Incisors During Tracheal Intubation With Double-Lumen Tubes and Different Laryngoscopy Techniques - A Blinded Mannequin Study

To quantify dental forces during double-lumen tube intubations with different laryngoscopy techniques. Experimental biomechanical mannequin study. Two German university hospitals. One hundred four anesthesiologists with varying levels of experience. Participants performed a sequence of intubations on a mannequin equipped with hidden forces sensors in the maxillary incisors. Different laryngoscopy techniques were evaluated under normal and difficult airway conditions. Direct laryngoscopy was compared with different videolaryngoscopy techniques: the C-MAC with a Macintosh blade, the GlideScope, and the KingVision with hyperangulated blades. A total of 624 intubations were evaluated. In normal airway conditions, the median (interquartile range [range]) peak forces were significantly lower when the GlideScope (15.7 (11.3-22.0 [2.1-110.5]) N) was used compared with direct laryngoscopy (21.0 (14.1-28.5[4.7-168.6]) N) (p=0.007). In difficult airways, resulting forces were reduced using hyperangulated videolaryngoscopes (GlideScope: -13.7 N [p < 0.001]; KingVision: -11.9 N [p < 0.001]) compared with direct laryngoscopy, respectively. The time to intubation was prolonged with the use of the KingVision (25.5 (17.1-41.9[9.2-275.0])s [p < 0.001]) in comparison to direct laryngoscopy (20.8 (15.9-27.4[8.7-198.6]) s). The C-MAC demonstrated the shortest time to intubation. Although hyperangulated videolaryngoscopes improve dental strain, clinicians also should consider the time to intubation, which is shortest with nonhyperangulated videoblades, when choosing a laryngoscopy technique on an individual patient basis.

Comparison of the success with two bending angles for lighted stylet intubation in children: A prospective randomised study.

The bend angle of a lighted stylet is an important factor for successful orotracheal intubation. The aim of this study was to test the differences in the success of endotracheal intubation using lighted stylet with 70° versus 90° bend angles in children aged 4-6years with normal airways. A total of 136 children with normal airways required orotracheal intubation were enrolled and were randomly allocated to the 90° or 70° bend angle groups. The first-attempt success rate was assessed as the primary outcome. The intubation time, lighted stylet search time, lighted stylet withdrawal time, hemodynamic responses, and perioperative complications were recorded as secondary outcomes. All intubations were completed within three attempts (the 90° group, 63/5/0; the 70° group, 55/11/2). The first-attempt success rate was higher in the 90° group than that in the 70° group (92.6% [63/68 patients] versus 80.9% [55/68 patients], respectively; risk ratio, 1.15; 95% CI, 1.01-1.31; p=.04). Esophageal entry occurred in nine of 83 intubation attempts in the 70° group and two of 73 intubation attempts in the 90° group (risk ratio, 1.09; 95% CI, 1.01-1.19; p=.04). The intubation time and the lighted stylet search time were significantly shorter in the 90° group than that in the 70° group (intubation time: 12.2±2.0s versus 14.9±2.6s, respectively; mean difference, 2.65; 95% CI, 1.87-3.43; p<.01; effect size, 1.16; lighted stylet search time: 5.4±1.0s versus 8.0±1.6s, respectively; mean difference, 2.66; 95% CI, 2.21-3.12; p<.01; effect size, 1.95). Lighted stylet intubation with a 90° bend angle improved the first-attempt success rate and reduced esophageal intubation in children aged 4-6years with normal airways.

Severe acute respiratory syndrome coronavirus 2 can be detected in exhaled aerosol sampled during a few minutes of breathing or coughing

BackgroundThe knowledge on the concentration of viral particles in exhaled breath is limited. The aim of this study was to explore if severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) can be detected in aerosol from subjects with the coronavirus disease 2019 (COVID‐19) during various types of breathing and coughing and how infection with SARS‐CoV‐2 may influence the number and size of exhaled aerosol particles.MethodsWe counted and collected endogenous particles in exhaled breath in subjects with COVID‐19 disease by two different impaction‐based methods, during 20 normal breaths, 10 airway opening breaths, and three coughs, respectively. Breath samples were analyzed with reverse transcription real‐time polymerase chain reaction (RT‐PCR).ResultsDetection of RNA in aerosol was possible in 10 out of 25 subjects. Presence of virus RNA in aerosol was mainly found in cough samples (n = 8), but also in airway opening breaths (n = 3) and in normal breaths (n = 4), with no overlap between the methods. No association between viral load in aerosol and number exhaled particles <5 μm was found. Subjects with COVID‐19 exhaled less particles than healthy controls during normal breathing and airway opening breaths (all P < 0.05), but not during cough.ConclusionSARS‐CoV‐2 RNA can be detected in exhaled aerosol, sampled during a limited number of breathing and coughing procedures. Detection in aerosol seemed independent of viral load in the upper airway swab as well as of the exhaled number of particles. The infectious potential of the amount of virus detected in aerosol needs to be further explored.

Concepts of advanced therapeutic delivery systems for the management of remodeling and inflammation in airway diseases.

Chronic respiratory disorders affect millions of people worldwide. Pathophysiological changes to the normal airway wall structure, including changes in the composition and organization of its cellular and molecular constituents, are referred to as airway remodeling. The inadequacy of effective treatment strategies and scarcity of novel therapies available for the treatment and management of chronic respiratory diseases have given rise to a serious impediment in the clinical management of such diseases. The progress made in advanced drug delivery, has offered additional advantages to fight against the emerging complications of airway remodeling. This review aims to address the gaps in current knowledge about airway remodeling, the relationships between remodeling, inflammation, clinical phenotypes and the significance of using novel drug delivery methods.

Tracheobronchitis in children with tracheostomy tubes: Overview of a challenging problem.

Tracheobronchitis is common in children with tracheostomy tubes. These children are predisposed to respiratory infections due to the bypassing of normal upper airway defense mechanisms by the tracheostomy, bacterial colonization of the tracheostomy tube itself, and underlying medical conditions. Diagnosis of bacterial tracheobronchitis is challenging due to the difficulty in differentiating between bacterial colonization and infection, as well as between viral and bacterial etiologies. Difficulty in diagnosis complicates management decisions, and there are currently no consensus guidelines to assist clinicians in the treatment of these patients. Frequent administration of systemic antibiotics causes adverse effects and leads to the emergence of resistant organisms. Topical administration of antibiotics via nebulization or direct instillation may lead to a significantly higher concentration of drug in the upper and lower airways without causing systemic side effects, although therapeutic trials in children with tracheostomy tubes are lacking. Several preventative measures such as regular airway clearance and the use of a speaking valve may mitigate the risk of developing respiratory infections.

Prevalence of laryngotracheal injury in chronically tracheostomized children at a large referral center

ObjectiveTo assess the prevalence and factors associated with laryngotracheal lesions in chronically tracheostomized children followed at a comprehensive care center for tracheostomized patients. Study designCross-sectional study. SettingTertiary care hospital. MethodsBetween 2011 and 2018, tracheostomized children were submitted to flexible bronchoscopy and divided into groups according to the findings: laryngotracheal injury without subglottic stenosis; laryngotracheal injury with subglottic stenosis; and normal airway. Multivariate analysis was performed with the covariates main indication for tracheostomy, age, duration of intubation, sex, and comorbidities. ResultsA total of 195 children were included, the median age at tracheostomy was 12 months, and upper airway obstruction was the indication for tracheostomy in 63.1%. Of the 195 patients evaluated, 41 (21%) had laryngotracheal injury without subglottic stenosis, 132 (67.7%) had laryngotracheal injury with subglottic stenosis, and 22 (11.3%) had a normal airway. In the final multivariate analysis, being intubated for ≥21 days increased the overall risk of subglottic stenosis (OR = 6.98; 95% CI, 1.42–34.3), which was significantly more common among the patients with laryngotracheal injury and subglottic stenosis than among those with laryngotracheal injury only and those with a normal airway (OR = 5.82; 95% CI, 1.44–23.52). ConclusionsIn our sample, the most prevalent lesion was subglottic stenosis The duration of intubation appears to be associated with the occurrence of laryngotracheal injury in tracheostomized children.

Comparison of airtraq™ versus C-MAC® videolaryngoscope for tracheal intubation in children with normal airways

Background and Aims: When compared with direct laryngoscopes, videolaryngoscopes can provide a significantly better view of the larynx. There are no studies in children directly comparing Airtraq™ and C-MAC® videolaryngoscopes. We aimed to compare intubating characteristics between these two devices in pediatric patients. The primary outcome measure was the time needed for successful intubation and secondary outcome measures were the number of attempts to intubate, ease of intubation, percentage of glottic opening (POGO) score, optimization maneuvers and complications such as airway trauma and esophageal intubation. Materials and Methods: One hundred and twelve children aged 1–12 years undergoing elective surgery under general anesthesia are quiring tracheal intubation were enrolled. Children were randomized into two groups using computer generated randomization sequence. The t-test was used for analyzing quantitative data, nonparametric data were analyzed using Mann–Whitney test, and categorical data were analyzed using the Chi-square test. Results: Time to tracheal intubation was significantly longer with Airtraq™ (41.0 s) compared to C-MAC® (23.4 s); P < 0.001. The number of attempts at tracheal intubation was more with Airtraq™ (P = 0.008). Seventy-five percent of anesthesiologists found C-MAC® easy to use. POGO score was >90% in both groups without maneuvers. Conclusion: The study found that in pediatric patients with normal airways, time to intubation was faster with C-MAC® as compared to AirtraqTM. C-MAC® also performed better in aspects like the number of attempts and ease of intubation.

Laryngoscopic View after Application of Manual In-Line Stabilization - A Comparison with Early Morning Sniffing Position in the Same Patient.

Background:The application of manual in-line stabilization (MILS) for minimizing spinal cord injury is known to increase difficulty in airway management.Aim:The study aims to assess the change in Modified Cormack–Lehane (CL) laryngoscopic view with the application of MILS from the early morning sniffing position (EMSP) in adult patients.Setting and Design:This was a prospective, interventional, self-controlled study conducted on 220 patients aged 18–65 years, belonging to the American Society of Anesthesiologists Physical Status Class I or II, having a normal airway, and scheduled for elective surgery under general anesthesia.Materials and Methods:After inducing general anesthesia, MILS was applied to the patient's neck, and a Modified CL view of the vocal cords was recorded under direct laryngoscopy. The view was again noted after applying backward-upward-rightward pressure (BURP). MILS and BURP were released. The view was obtained again with and without BURP in EMSP.Statistical Analysis:Normality of data was tested by Kolmogorov–Smirnov test. Wilcoxon ranked-sum test for quantitative variables and Chi-square test for qualitative variables were used.Results:On application of MILS, the majority of patients had Modified CL Grade 3a (121 patients) and 3b (53 patients) views. The majority of patients had Modified CL Grade 1 (114 patients) and 2a (71 patients) views on placing in EMSP. These findings were statistically significant (P < 0.0001). Consequent to the placement of BURP upon MILS, patients with lower CL Grade views (2b: 101 patients) were significantly higher (P < 0.0001) in comparison with MILS alone.Conclusion:In patients with a normal airway, MILS leads to a significantly greater incidence of higher grades of laryngoscopic views in comparison to EMSP. Use of BURP after MILS causes significantly less incidence of higher grades of laryngoscopic view when compared with MILS alone. All patients requiring MILS should be considered to be a difficult airway, and hence, preparation should be done accordingly.