Laryngeal photobiomodulation: application sites, interferences from body mass index and skin phototype.

PURPOSE: Establish points on the neck, correspondent to the laryngeal topography, where to apply Low Level Light therapy (LLLT), to evaluate the incidence of light through variables such as skin phototype and body mass index (BMI). METHODS: This is a cross-sectional, analytical, observational study, carried out with 15 vocally healthy women, between 18 and 50 years of age, who were divided into three groups, according to BMI and skin phototype. Six anatomical reference points were established to locate the larynx and its musculature, with visual monitoring by videonasolaryngoscopy, to assess light reach (present/absent) and degree of illumination (from very weak to very strong) in the larynx during the LASER application at doses of 3J, 6J and 9J. A flexible endoscope was used for visual monitoring during the LASER application, and subsequent image analysis. RESULTS: The light reached the larynx at doses of 3J, 6J and 9J, in the anterior commissure of the vocal folds, membranous (thyroarytenoid muscle) and cartilaginous portions of the vocal fold and the cricothyroid muscle. The degree of LASER light illumination decreased in overweight and obese participants and increased in moderate brown and dark brown skin phototypes. CONCLUSION: Data suggest that the LLLT penetrates differently according to skin phototype and BMI, being more evident in individuals with Fitzpatrick IV and V phototypes and less evident with higher BMI levels. The evidence that the LASER light reaches the larynx in specific anatomical points provides direction for the standardization of its use in voice practice.

Quantitative Morphological Study of Larynx APUD-Cells in Asphyxial Type of Drowning in Fresh Water (Experimental Study).

An additional microscopic diagnostic sign has been identified for verification of asphyxial type of drowning. In white non-linear male rats (age 2 months) subjected to free drowning, significant hyperplasia of argyrophilic and morphofunctional activity of serotonin-containing APUD-cells of the laryngeal mucosa were revealed under conditions of acute anoxia in comparison with the intact control. These changes promote the development of laryngospasm, which prevents water penetration into the airways and lungs in asphyxial type of drowning. The presence of statistically significant hyperplasia of argyrophilic and morphofunctional activity of serotonin-containing APUD-cells of the laryngeal mucosa under conditions of acute anoxia can be used as an additional diagnostic criterion for asphyxial type of drowning in experimental studies.

Oxygen reserve index versus conventional peripheral oxygen saturation for prevention of hypoxaemia: A randomised controlled trial.

BACKGROUND: Hypoxaemia occurs frequently during paediatric laryngeal microsurgery. OBJECTIVE: The oxygen reserve index is a noninvasive and continuous parameter to assess PaO2 levels in the range of 100 to 200 mmHg. It ranges from 0 to 1.0. We investigated whether monitoring the oxygen reserve index can reduce the incidence of SpO2 90% or less. DESIGN: Randomised controlled trial. SETTING: A tertiary care paediatric hospital. PARTICIPANTS: Paediatric patients aged 18 years or less scheduled to undergo laryngeal microsurgery. INTERVENTION: The patients were randomly allocated to the oxygen reserve index or control groups, and stratified based on the presence of a tracheostomy tube. Rescue intervention was performed when the oxygen reserve index was 0.2 or less and the SpO2 was 94% or less in the oxygen reserve index and control groups, respectively. MAIN OUTCOME MEASURE: The primary outcome was the incidence of SpO2 90% or less during the surgery. RESULTS: Data from 88 patients were analysed. The incidence of SpO2 ≤ 90% did not differ between the oxygen reserve index and control groups [P = 0.114; 11/44, 25% vs. 18/44, 40.9%; relative risk: 1.27; and 95% confidence interval (CI): 0.94 to 1.72]. Among the 128 rescue interventions, SpO2 ≤ 90% event developed in 18 out of 75 events (24%) and 42 out of 53 events (79.2%) in the oxygen reserve index and control groups, respectively (P < 0.001; difference: 55.2%; and 95% CI 38.5 to 67.2%). The number of SpO2 ≤ 90% events per patient in the oxygen reserve index group (median 0, maximum 3) was less than that in the control group (median 0, maximum 8, P = 0.031). CONCLUSION: Additional monitoring of the oxygen reserve index, with a target value of greater than 0.2 during paediatric airway surgery, alongside peripheral oxygen saturation, did not reduce the incidence of SpO2 ≤ 90%.

[The use of the dura mater at the final stage of reconstructive plastic surgical treatment of cicatricial stenosis of the larynx and trachea]. / Ispol'zovanie tverdoi mozgovoi obolochki pri zaklyuchitel'nom etape rekonstruktivno-plasticheskogo operativnogo lecheniya rubtsovogo stenoza gortani i trakhei.

The article presents an analysis of the plastic reconstructive surgery effectiveness for patients with an extended tracheal defect using an allograft based on the dura mater (DM) at the final stage of surgical treatment of laryngeal and tracheal cicatricial stenosis. The study included 20 patients with cicatricial stenosis of the larynx and trachea, who were previously performed plastic reconstructive treatment with scar tissue excision in the lumen of the respiratory tract and restoration of the supporting frame of the larynx and trachea using allografts based on costal allocartilage. The age of the patients ranged from 21 to 54 years, the duration of the disease was from 1 to 5 years. After a standard clinical and laboratory examination, with a mandatory video endoscopic examination of the larynx and trachea, multislice computed tomography of the larynx and trachea, patients underwent plastic closure of the tracheal defect using DM. Dynamic outpatient monitoring was carried out once a week for 1 month, once a month for 3 months, control examination was done 6 months after surgical treatment. The results of the study demonstrated a full-fledged social and labor rehabilitation of all 20 patients after the final stage of surgical treatment using DM, the absence of rejection reaction and migration of allo-implantation material, the preserved lumen of the larynx and trachea with a rigid supporting skeleton and the absence of anterior tracheal wall floatation. The use of DM as an additional strengthening of the anterior tracheal wall for patients with deficiency of muscular aponeurotic tissues and more than 2 cm size tracheal defect is highly effective at the final stage of surgical treatment for plastic closure of the tracheal defect.

[Diagnosis of benign laryngeal tumors using neural network]. / Diagnostika dobrokachestvennykh novoobrazovanii gortani s primeneniem neiroseti.

The article describes our experience in developing and training an artificial neural network based on artificial intelligence algorithms for recognizing the characteristic features of benign laryngeal tumors and variants of the norm of the larynx based on the analysis of laryngoscopy pictures obtained during the examination of patients. During the preparation of data for training the neural network, a dataset was collected, labeled and loaded, consisting of 1471 images of the larynx in digital formats (jpg, bmp). Next, the neural network was trained and tested in order to recognize images of the norm and neoplasms of the larynx. The developed and trained artificial neural network demonstrated an accuracy of 86% in recognizing of benign laryngeal tumors and variants of the norm of the larynx. The proposed technology can be further used in practical healthcare to control and improve the quality of diagnosis of laryngeal pathologies.

Gekko gecko as a model organism for understanding aspects of laryngeal vocal evolution.

The ability to communicate through vocalization plays a key role in the survival of animals across all vertebrate groups. Although avian reptiles have received much attention relating to their stunning sound repertoire, non-avian reptiles have been wrongfully assumed to have less elaborate vocalization types, and little is known about the biomechanics of sound production and their underlying neural pathways in this group. We investigated alarm calls of Gekko gecko using audio and cineradiographic recordings. Acoustic analysis revealed three distinct call types: a sinusoidal call type (type 1); a train-like call type, characterized by distinct pulse trains (type 3); and an intermediate type, which showed both sinusoidal and pulse train components (type 2). Kinematic analysis of cineradiographic recordings showed that laryngeal movements differ significantly between respiratory and vocal behavior. During respiration, animals repeatedly moved their jaws to partially open their mouths, which was accompanied by small glottal movements. During vocalization, the glottis was pulled back, contrasting with what has previously been reported. In vitro retrograde tracing of the nerve innervating the laryngeal constrictor and dilator muscles revealed round to fusiform motoneurons in the hindbrain-spinal cord transition ipsilateral to the labeled nerve. Taken together, our observations provide insight into the alarm calls generated by G. gecko, the biomechanics of this sound generation and the underlying organization of motoneurons involved in the generation of vocalizations. Our observations suggest that G. gecko may be an excellent non-avian reptile model organism for enhancing our understanding of the evolution of vertebrate vocalization.

[The clinical treatment of laryngotracheal rupture injury].

Objective:To investigate the therapeutic effect of laryngotracheal rupture injury and management of related complications. Methods:A retrospective analysis was conducted on 10 patients with laryngotracheal rupture injury caused by trauma, admitted between October 2014 and October 2022. Results:Anti-shock treatment, local debridement, tracheal-cricoid cartilage or tracheal-tracheal anastomosis, laryngeal cartilage reduction and fixation, local transposition flaps repair and phase-Ⅱ airway reconstruction were performed respectively on 10 patients. Nine patients underwent operations of tracheal-cricoid cartilage or tracheal-tracheal anastomosis, with five of these were performed by cartilage broken reduction and fixation, placed with intraluminal stents of iodoform gauze fingerstalls for （8.2±1.6） days. Tracheal reconstruction surgery was performed on 2 cases during phase-Ⅱ and both were placed with T-shaped silicone tube to support for 3 months. Two cases required tracheoesophageal fistula surgical repair, and vocal cord suturing was conducted for three vocal fold injuries. Anti-shock treatment was given to one emergency case and closed thoracic drainage treatment was given to another one. We removed the tracheal cannula from 10 patients after surgery and one case was diagnosed with Ⅰ-level swallowing function of sub-water test. All cases recovered to take food per-orally. Conclusion:Maintenance of circulation and respiration functions is the major target during early treatment of laryngotracheal rupture. It should strive to complete the reconstruction of airway structure on phase-Ⅰ, among which end-to-end anastomosis to reconstruct airway and broken laryngeal cartilage reduction and fixation are the vital methods for airway structure reconstruction to achieve good results. It is suggested that the reconstruction of trachea and esophagus structures should be performed simultaneously to patients with tracheoesophageal fistula.

[Hyoid epiglottis combined with sternocleidomastoid muscle clavicle flap for repairing laryngeal defect after laryngeal trauma infection: a case report].

The initial treatment of open laryngeal trauma must be implemented immediately, with the primary focus on saving lives. However, in the later stages, various factors may cause changes in the structure and function of the larynx, which requires special attention. This article reports on the treatment process of a patient with depression who suffered from laryngeal trauma. Due to the late stage of laryngeal infection causing laryngeal defects, a hyoid epiglottis combined with sternocleidomastoid muscle clavicular flap repair was performed. Additionally, personalized functional exercise was performed, ultimately resulting in recovery.

Principal dimensions of voice production and their role in vocal expression.

How we produce and perceive voice is constrained by laryngeal physiology and biomechanics. Such constraints may present themselves as principal dimensions in the voice outcome space that are shared among speakers. This study attempts to identify such principal dimensions in the voice outcome space and the underlying laryngeal control mechanisms in a three-dimensional computational model of voice production. A large-scale voice simulation was performed with parametric variations in vocal fold geometry and stiffness, glottal gap, vocal tract shape, and subglottal pressure. Principal component analysis was applied to data combining both the physiological control parameters and voice outcome measures. The results showed three dominant dimensions accounting for at least 50% of the total variance. The first two dimensions describe respiratory-laryngeal coordination in controlling the energy balance between low- and high-frequency harmonics in the produced voice, and the third dimension describes control of the fundamental frequency. The dominance of these three dimensions suggests that voice changes along these principal dimensions are likely to be more consistently produced and perceived by most speakers than other voice changes, and thus are more likely to have emerged during evolution and be used to convey important personal information, such as emotion and larynx size.

Morphological comparison of the larynx and trachea of Chelonia mydas (Linnaeus, 1758), Caiman yacare (Daudin, 1802) and Caiman latirostris (Daudin, 1802).

The larynx is in the lower respiratory tract and has the function of protecting the airways, controlling, and modulating breathing, assisting the circulatory system, and vocalizing. This study aims to describe the anatomy and histology of the skeleton of the larynx and trachea of the species Chelonia mydas, Caiman yacare and Caiman latirostris. The study was conducted at the Federal University of Espírito Santo (UFES), using nine specimens of Ch. mydas, 20 of Ca. yacare and four of Ca. latirostris. Samples of the larynx and trachea were collected, fixed, and sent for dissection of the structures and subsequent macroscopic analysis. For histology, samples were processed by the routine paraffin embedding method and stained with hematoxylin-eosin and Verhoeff. For the three species, two arytenoid cartilages, a cricoid cartilage, a hyoid apparatus composed of a base and two horns were found. In Ch. mydas, two structures called thyroid wings were observed, not found in crocodilians. The trachea of crocodilians presented incomplete tracheal rings and musculature, while the trachea of Ch. mydas presented complete tracheal rings. Histologically, the entire cartilaginous skeleton of the larynx of the three species, as well as the tracheal rings, are constituted by hyaline cartilage.

An investigation of acoustic cues to tonal registers and voicing in Donglei Kama).

The Kam language has experienced historical tonal splits, resulting in the development of a complex tonal system. However, there is still limited knowledge regarding the acoustic characteristics associated with aspiration-based tone splitting. This study aims to investigate the acoustic cues related to the tonal registers and laryngeal configurations in Donglei Kam, a dialect of Southern Kam. Sixteen native speakers of Donglei Kam participated, producing lexical tones. Statistical analyses were conducted to examine the acoustic distinctions between tonal registers, using measurements of voice onset time, spectral tilt, noise, and energy. The results indicated that Donglei Kam retained a two-way contrast of aspiration, albeit with a trend toward gradual loss. Additionally, a breathy voice was detected in the Ciyin tonal register, characterized by elevated spectral tilt values and spectral noise throughout the vowels. Moreover, machine learning classifiers effectively identified tonal registers using voice-quality data, suggesting that the phonation contrast between breathy and modal voice could contribute to the tonal split alongside pitch contrast. In summary, these findings enhance our understanding of the acoustic implementation of breathiness in Kam and offer valuable insights into the role of laryngeal contrast in tonal splits.

Uncovering the neural control of laryngeal activity and subglottic pressure in anaesthetized rats: insights from mesencephalic regions.

To assess the possible interactions between the dorsolateral periaqueductal gray matter (dlPAG) and the different domains of the nucleus ambiguus (nA), we have examined the pattern of double-staining c-Fos/FoxP2 protein immunoreactivity (c-Fos-ir/FoxP2-ir) and tyrosine hydroxylase (TH) throughout the rostrocaudal extent of nA in spontaneously breathing anaesthetised male Sprague-Dawley rats during dlPAG electrical stimulation. Activation of the dlPAG elicited a selective increase in c-Fos-ir with an ipsilateral predominance in the somatas of the loose (p < 0.05) and compact formation (p < 0.01) within the nA and confirmed the expression of FoxP2 bilaterally in all the domains within the nA. A second group of experiments was made to examine the importance of the dlPAG in modulating the laryngeal response evoked after electrical or chemical (glutamate) dlPAG stimulations. Both electrical and chemical stimulations evoked a significant decrease in laryngeal resistance (subglottal pressure) (p < 0.001) accompanied with an increase in respiratory rate together with a pressor and tachycardic response. The results of our study contribute to new data on the role of the mesencephalic neuronal circuits in the control mechanisms of subglottic pressure and laryngeal activity.

Anatomical and Surface Electron Microscopic Investigation of the Tongue and Laryngeal Prominence in the Red-Eyed Turtle Dove (Streptopelia semitorquata, Rüppel 1837).

This study investigated the morphology of tongue and laryngeal structures in red-eyed dove and related it to feeding habits. Samples were examined using gross anatomy, scanning electron microscopy (SEM), and histological techniques. The tongue conformed to the shape of the lower beak, and the apex with a pointed tip, body, and root were distinguished. A median grove was apparent, and a papillary crest with pointed triangular papillae separated the body from the root. The length of the tongue, its width (body), and the percentage of the length of the lower jaw occupied by the tongue were, on average, 12.5 mm, 2.3 mm, and 57.3%, respectively. SEM showed highly desquamated dorsal epithelium with pointed papillae-like projections. The papillary crest presented pointed papillae of about 20-22. Salivary openings were apparent in the root, surrounded by mucosal folds and blunt papillae. Laryngeal prominence was irregularly triangular shaped and elevated. The rim of the glottis showed glandular pinpointed marks. Typical cornified multilayered mucosal epithelium was present in the apex and decreased caudally. Hyaline entoglossal cartilage and adjoining connective tissue were present in the body and apex. Numerous tubuloalveolar glands were seen in the body and root. The rim of the glottis showed mucous intraepithelial glands. The rostral and caudal lingual glands indicated positive reaction to neutral and acidic mucins. This study demonstrated a morphofunctional relationship of the tongue of a red-eyed dove to its diet.

Physiological Biomarkers for Assessment of Pain during Routine Blood Tests for Older Adults with Dementia in Long-Term Residential Care.

OBJECTIVE: Evaluating pain in individuals with dementia can be difficult when verbal communication is limited. Vocalization has emerged as a potential avenue for assessments of pain in nonverbal populations. This study aimed to evaluate if physiological assessments of vocalization were correlated with observational assessments of pain during routine blood tests for persons with dementia. DESIGN: A cross-sectional descriptive study. SETTING AND PARTICIPANTS: Sixty older adults (aged ≥65 years old) with dementia requiring routine finger puncture and peripheral venipuncture for routine blood tests were recruited by purposive sampling from 3 long-term care facilities in Taiwan. METHODS: Observational assessments were conducted with the Pain Assessment in Advanced Dementia (PAINAD) instrument; physiological biomarkers of vocalization were assessed with a noninvasive sensing device and microphone (NISDM). Assessments were conducted simultaneously in one session during situations of increasing pain levels: at rest, making a sound, finger puncture, and peripheral venipuncture. PAINAD scores were compared with signal recording measures from the NISDM. Analysis of variance and Pearson correlation coefficient assessed correlations between observational and physiological measures. RESULTS: Most participants were female (63.3%); mean age was 81.27 years (SD = 9.69); Clinical Dementia Rating was 2.23 ± 0.70; and Mini-Mental State Examination was 7.07 ± 6.95. Signal recording measures using the NISDM during finger puncture and venipuncture were significantly greater compared with measures at rest and making sound, indicating higher signal levels were associated with pain. PAINAD scores were significantly correlated with physiological measures for vocalization variables of sound amplitude (r = 0.49, P < .001), shimmer (r = 0.63, P < .001), and inhalation-to-exhalation amplitude ratio (r = 0.48, P < .001). CONCLUSIONS AND IMPLICATIONS: Elevated vocalizations detected with the NISDM were correlated with increased pain scores on the PAINAD instrument. Physiological measures of pain using novel vocalization biomarkers have the potential to enhance the quality of care for individuals with dementia and limited communication abilities.

Do tight nosebands have an effect on the upper airways of horses?

BACKGROUND/OBJECTIVES: The public perception relating to the welfare of horses involved with equestrian sports is associated with training methods used and the presentation of horses at events. In this context, very tight nosebands, which are intended to prevent the horse from opening its mouth, also attract a lot of attention. Various studies have evaluated the impact of tight nosebands on stress parameters, whereas the effect of tight nosebands on upper airway function is unknown. Therefore, the aim of the study was to use overground endoscopy to evaluate changes in pharyngeal and laryngeal function when a tight noseband is fitted. Moreover, the ridden horse pain ethogram (RHpE) was applied to investigate signs of discomfort (Dyson et al., 2018). STUDY DESIGN: A randomized, blinded, and prospective study was performed. METHODS: Sixteen warmblood horses consisting of twelve mares and four geldings with a mean age of 11.63 ± 3.53 years were ridden on 2 consecutive days with either loose or tight nosebands (two fingers or no space between bridge of the nose and noseband, respectively) and inserted endoscope in a random order. Videos were taken in a riding arena during a standardized exercise protocol involving beginner level tasks for 30 min in all gaits. For video analysis, freeze frames were prepared and analyzed at the beginning of the expiration phase. Pharyngeal diameter was measured using the pharynx-epiglottis ratio. Other findings (swallowing, pharyngeal collapse, soft palate movements, and secretion) were also evaluated. Moreover, the RHpE was applied. Descriptive statistics and generalized linear mixed effects models were used. Results with a p-value < 0.05 were considered statistically significant. RESULTS: While the pharynx-epiglottis ratio did not change significantly in horses ridden with loose versus tight nosebands, there was an increase in mean grade and total counts of parameters assessed in the pharyngeal region, for example, grade of secretion (1.5 [±SD 0.89] vs. 3.13 [±SD 0.96]; p = 0.0001), axial deviation of the aryepiglottic folds (0.29 [±SD 0.73] vs. 1.33 [±SD 1.44]; p = 0.01), and pharyngeal collapse (0.69 [±SD 0.87] vs. 1.88 [±SD 1.54]; p = 0.005) in horses ridden with tight nosebands. There was no RHpE score above 8 indicating musculoskeletal pain, but the RHpE scores were significantly higher in horses ridden with tight nosebands (p < 0.001). MAIN LIMITATIONS: Video quality was limited when horses showed large amounts of secretion. Another limitation was the small number of horses. CONCLUSIONS: Results add to the evidence obtained in other studies that tight nosebands do not only cause adverse reactions based on the RHpE score such as head behind the vertical or intense staring but also contribute to changes in the pharyngeal region, such as increased secretion and collapse of pharyngeal structures. This may provide further support for future decisions regarding regulations on nosebands.

Gossypiboma larynx: a rare cause of post-tracheostomy stridor-case report and review of literature.

BACKGROUND: Gossypiboma, a retained surgical sponge with a foreign body reaction, is an unusual but serious complication seen in open abdominal surgeries. It is exceptionally rare following head and neck surgeries. Here, we present a case of Gossypiboma of the upper airway following tracheostomy. CASE PRESENTATION: A 32-year-old male presented with stridor and difficulty breathing one-month post-tracheostomy after a severe head injury following a road traffic accident. A neck radiograph was unremarkable, and a computed tomography (CT) scan of the neck showed a well-defined homogenous curvilinear membrane extending from the hypopharynx to the upper trachea. Bronchoscopic evaluation of the larynx and upper trachea revealed a retained surgical sponge, which was retrieved. The patient's breathing improved drastically post intervention. CONCLUSION: Gossypiboma may go undetected in radiographs and may also present atypically as a homogenous membrane on a CT scan of the neck. Though rare, retained surgical items can have profound medicolegal and professional consequences on physicians. Hence, a strong clinical suspicion and vigilance for gossypiboma is necessary for patients presenting with respiratory distress post-tracheostomy.

Neoadjuvant Chemotherapy Improves Feasibility of Larynx Preservation and Prognosis in Resectable Locally Advanced Cervical Esophageal Cancer.

BACKGROUND: The optimal strategy for cervical advanced esophageal cancer remains controversial in terms of oncologic outcome as well as vocal and swallowing function. Recently, in East Asian countries, neoadjuvant chemotherapy (NAC) has been a standard strategy for advanced esophageal cancer. METHODS: This study included 37 patients who underwent NAC, and 33 patients who underwent definitive chemoradiation therapy (dCRT) as larynx-preserving treatment for locally advanced cervical esophageal cancer from 2016 to 2021. This study retrospectively investigated outcomes, with comparison between NAC and dCRT for locally advanced cervical esophageal cancer. RESULTS: Larynx preservation was successful for all the patients with NAC and dCRT. After NAC, the rate of complete or partial response was 78.4%, and 30 patients underwent larynx-preserving surgery. On the other hand, after dCRT, the complete response rate was 71.9%, and 4 patients underwent larynx-preserving salvage surgery. Overall survival (OS) and progression free survival were similar between the two groups. However, for the patients with resectable cervical esophageal cancer (cT1/2/3), the 2-year OS rate was significantly higher with NAC (79.9%) than with dCRT (56.8%) (P = 0.022), and the multivariate analyses identified only NAC and cN0, one of the two as a significantly independent factor associated with a better OS (NAC: P = 0.041; cN0, 1: P = 0.036). CONCLUSION: The study showed that NAC as larynx-preserving surgery for resectable cervical esophageal cancer preserved function and had a better prognosis than dCRT. The authors suggest that NAC may be standard strategy for larynx preservation in patients with resectable cervical esophageal cancer.

Sleep apnea patients with epiglottic collapse elevate their larynx more with swallowing; videofluoroscopic swallowing study of 80 patients.

OBJECTIVE: The epiglottis plays an integral role in the swallowing mechanism and is also implicated as an obstruction site in obstructive sleep apnea (OSA). The underlying causes of epiglottic collapse during sleep remain unclear. This study aimed to investigate the cognitive functions using the Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) and the neurophysiological and anatomical factors using videofluoroscopic swallowing studies (VFSS). We compared patients with OSA exhibiting epiglottic collapse to those without, assessing differences in anatomical or neurophysiological characteristics. METHODS: The study included 12 patients with epiglottic collapse (Epi-group) and 68 without (non-Epi group), all undergoing overnight polysomnography (PSG), drug-induced sleep endoscopy (DISE), LOTCA, and VFSS. Oral transit time (OTT), pharyngeal delay time (PDT), and pharyngeal transit time (PTT) were considered as neurophysiological traits, and laryngeal elevation length (LE) as anatomical trait, and were measured across various test diets (10 ml of liquid, soft, or solid). RESULTS: The study comprised 80 individuals, 57 men and 23 women, with no significant age, sex, body mass index or PSG parameters between groups, or DISE findings, with the exception of epiglottic collapse. Swallowing metrics from VFSS were normal, with no differences in OTT, PDT, PTT, or LOTCA scores. Notably, patients with epiglottic collapse showed a greater laryngeal elevation when swallowing soft and solid foods (p = 0.025 and p = 0.048, respectively). CONCLUSIONS: Patients with epiglottic collapse do not exhibit neurophysiological or cognitive impairments when compared to non-Epi group. However, the Epi-group displayed a significantly increased laryngeal elevation length. This suggests that anatomical factors may have a more substantial role in the development of epiglottic collapse than neurophysiological factors.

Oxygen concentration titration guided by oxygen reserve index during pediatric laryngeal surgery with high-flow nasal cannula oxygen: a randomized controlled trial.

PURPOSE: The objective of this study was to evaluate whether adjusting the oxygen concentration guided by the Oxygen Reserve Index (ORI) during pediatric laryngeal surgery with High Flow Nasal Cannula Oxygen (HFNO) could achieve postoperative PaO2 close to physiological levels while ensuring adequate oxygenation in surgery. METHODS: Sixty pediatric patients undergoing laryngeal surgery or examination were randomly assigned to two groups. The ORI group received oxygen concentration adjustments every 5 min to maintain a target ORI value of 0.21, whereas the control group did not undergo any adjustments. Postoperative PaO2, time weighted average fraction of inspired oxygen (FiO2), and mean Peripheral Oxygen Saturation (SpO2) were compared between groups. Finally, some analyses were conducted to examine the relationship of ORI with PaO2. RESULTS: In general, the postoperative PaO2 was 164.9 ± 48.8 mmHg in ORI group and 323.0 ± 87.7 mmHg in control group (P < 0.01). The time weighted average FiO2 in the ORI group was 85.9 [81.8-92.7] %. There was no significant difference in mean SpO2 between the two groups (ORI vs. control: 98.4 [97.7-99.2] vs. 98.8 [97.7-99.5]; P = 0.36). According to the analyses, the optimal cut value for ORI was determined to be 0.195 when PaO2 was 150 mmHg. CONCLUSIONS: In pediatric laryngeal surgery with HFNO, reducing oxygen concentration guided by ORI helped achieve postoperative PaO2 levels closer to physiological norms without compromising intra-operative oxygenation.

Non-inferiority randomized controlled trial comparing CricOid pressure and para-laryngeal pressure in parturients undergoing cesarean delivery: NiCOP trial.

BACKGROUND: Cricoid pressure has been surrounded with controversies regarding its effectiveness. Application of ultrasound-guided para-laryngeal (PL) force has been shown to occlude the esophagus effectively compared with cricoid pressure (CP) in awake patients. We hypothesized that there would be no meaningful difference in the change in antero-posterior esophageal diameter from with application of cricoid or para-laryngeal pressure in parturients undergoing cesarean delivery under general anesthesia. METHODS: In this prospective, randomized, non-inferiority trial, 40 parturients scheduled for elective cesarean delivery under general anesthesia were randomized to receive rapid sequence induction with either cricoid pressure (n = 20) or para-laryngeal pressure (n = 20). The antero-posterior diameter of the esophagus, measured by sonography, was the primary outcome. Visualization of the esophagus, its position in relation to the glottic aperture, esophageal occlusion, percentage of glottic opening (POGO), time to intubation, first pass success rate, overall success rate and adverse events like desaturation or bronchospasm were secondary outcomes. RESULTS: The mean change in anterior-posterior diameter in the CP group was 0.17 ±0.1 cm vs. 0.28 ±0.1 cm in the PL group. The mean difference (CP-para-laryngeal pressure) between the groups was -0.11 (95% CI -0.17 to -0.1) cm. As the upper limit of the 95% CI was lower than the prespecified non-inferiority margin (δ = -0.2), non-inferiority was established (P <0.001]. There was no significant difference in the POGO score (P = 0.818), time to intubation (P =0.55), or intubation attempts (P = 0.99). CONCLUSIONS: Para-laryngeal pressure was non-inferior to CP in occluding the esophagus in parturients undergoing cesarean delivery under general anesthesia and furthermore, no significant deterioration in intubation parameters was seen.