P149 The role of OSA pathophysiological traits on mandibular advancement treatment response and efficacy of a novel mandibular advancement device

Mandibular advancement devices (MAD) are an effective therapy for OSA. However, treatment response is difficult to predict. Recent studies have investigated the influence of OSA endotypes on MAD outcomes albeit using simplified endotyping methods. We aimed to prospectively quantify and compare OSA pathophysiological traits between responders and non-responders to a novel MAD using gold-standard endotyping methodology. Data from 30 OSA patients (AHI>10events/h) are analysed to date. OSA was confirmed via in-laboratory polysomnography. Next, a detailed physiology night was conducted before MAD therapy. Participants were instrumented with EEG, nasal mask, pneumotachograph, epiglottic pressure catheter and intramuscular genioglossus electrodes to quantify baseline OSA pathophysiological traits. Pcrit was quantified via CPAP drops and non-anatomical traits from naturally occurring respiratory events. Participants were fitted with a novel MAD with a built-in oral airway (Oventus O2Vent Optima™) and titrated to ≥75% of maximum mandibular advancement. A treatment efficacy PSG followed therapy acclimatisation. OSA severity decreased by 41±30% (25.1[16.3,39.2] vs. 12.1[7.3,20.0] events/h P<0.001) with MAD therapy. Similar reductions occurred in participants with high nasal resistance. OSA pathophysiological traits measured by gold-standard methodology were similar between responders and non-responders to MAD (residual AHI>10events/h). MAD responders had less collapsible airways at baseline when measured using simple estimates (Vpassive: 92.5[86.3,97.0] vs. 72.5[43.0,91.3] %Veupnea, P=0.022). The novel MAD reduced OSA severity by ~40% including in those with nasal obstruction. The upper airway was less collapsible in responders to MAD when estimated but not when directly measured. Simple estimates of OSA pathophysiological traits may be used to predict responses to MAD.

Anesthetic Management of a Juvenile Hyaline Fibromatosis Patient With Trismus and Cervical Movement Limitation

Juvenile hyaline fibromatosis (JHF) is a rare autosomal recessive disease characterized by the presence of tissue nodules, joint contractures, and gingival hyperplasia. With a 1-year-9-month-old female patient scheduled for a gingivectomy and excision of a lower lip mass under general anesthesia, it was anticipated that airway management would be difficult because of trismus and limited cervical movement. Intubation with video-laryngoscopic assistance could not be achieved because gingival hyperplasia and trismus prevented blade insertion and manipulation. Therefore, 2 endotracheal tubes were used: 1 used as a nasopharyngeal airway for assisted ventilation, and 1 used for intubation along with a flexible fiberoptic scope. This case demonstrated a useful method for managing ventilation and intubation in patients with JHF, particularly when the use of oral airway devices is difficult.

437 Efficacy of a novel oral appliance and the influence of OSA pathophysiological traits on treatment response

Introduction Oral appliance therapy is a recommended alternative to CPAP for OSA. Approximately 50% of patients have a major reduction in OSA severity but successful treatment outcome remains challenging to predict. Previous prediction methods have focused on clinical variables which have poor predictive value. OSA is recognised as a heterogenous disorder caused by 4 pathophysiological traits. The influence of OSA pathophysiological traits on oral appliance treatment outcome has been explored in recent physiological studies using simplified phenotyping methods. In this preliminary report, we prospectively compared differences in the 4 OSA phenotypes between responders and incomplete responders to a novel oral appliance with built in oral airway using gold standard phenotyping methodology. Methods Data from 22 people with OSA (AHI>10events/h) have been analysed to date. A diagnostic in-laboratory PSG was initially conducted to confirm OSA. A detailed physiology PSG was carried out prior to commencement of oral appliance therapy. For this study night participants were instrumented with standard PSG equipment, nasal mask, pneumotachograph, epiglottic pressure catheter and intramuscular electrodes inserted perorally into the genioglossus to quantify baseline OSA phenotypic traits. Pcrit was quantified via CPAP dial downs and the non-anatomical traits were quantified from naturally occurring apneas and hypopneas. Participants were then fitted with a next generation novel oral appliance with a built-in oral airway (Oventus O2Vent Optima™) and titrated to at least 75% of maximum mandibular advancement. After acclimatization to therapy, participants were invited to undergo a treatment efficacy PSG. Results Oral appliance therapy reduced the AHI by 52% (21[15,31] vs. 11[7,16] events/h, p<0.001). 46% of participants responded to oral appliance therapy based on the definition of AHI < 10events/h. Preliminary analyses indicated that estimates of baseline upper airway collapsibility tended to be different in responders versus non-responders (responders have less collapsible airways). Conclusion The novel oral appliance reduced OSA severity by 50% with resolution of OSA in half of participants. Baseline pharyngeal collapsibility may be an important physiological predictor of treatment outcome. Support (if any):

The Articulated Oral Airway as an aid to mask ventilation: a prospective, randomized, interventional, non-inferiority study

Background Oropharyngeal airways are used both to facilitate airway patency during mask ventilation as well as conduits for flexible scope intubation, though none excel at both. A novel device, the Articulated Oral Airway (AOA), is designed to facilitate flexible scope intubation by active displacement of the tongue. Whether this active tongue displacement also facilitates mask ventilation, thus adding dual functionality, is unknown. This study compared the AOA to the Guedel Oral Airway (GOA) in regards to efficacy of mask ventilation of patients with factors predictive of difficult mask ventilation. The hypothesis was that the AOA would be non-inferior to the GOA in terms of expiratory tidal volumes by a margin of 1 ml/kg, thus demonstrating dual functionality. Methods In this randomized controlled clinical trial, fifty-eight patients with factors predictive of difficult mask ventilation were mask ventilated with both the GOA and the AOA. Video of the anesthetic monitors were evaluated by a blinded member of the research team, noting inspiratory and expiratory tidal volumes and expiratory CO2 waveforms. Results The AOA was found to be non-inferior to the GOA at a margin of 1 ml/kg with a mean weight-standardized expiratory tidal measurement 0.45 ml/kg lower (CI: 0.34–0.57) and inspiratory tidal measurement 0.109 lower (CI: − 0.26-0.04). There was no significant difference in expiratory waveforms (p = 0.2639). Conclusions The AOA was non-inferior to the GOA for mask ventilation of patients with predictors of difficult mask ventilation and there was no significant difference in EtCO2 waveforms between the groups. These results were consistent in the subset of patients who were initially difficult to mask ventilate. Trial registration ClinicalTrials.gov, NCT03144089, May 2017.

CONGENITAL CHOANAL ATRESIA: A CASE SERIES

Congenital Choanal Atresia (CA) is the failure in the development in communication between the nasal cavity and the nasopharynx. Its incidence is 1 in 7000 births. The male to female ratio for infants with choanal atresia is 2.2. Approximately two-thirds of cases are unilateral. Structurally there are two main types– a) Osseous-90% b) Membranous. Bilateral CA is an important but rare cause of respiratory distress in newborn. The distress improves with an oral airway. Here 3 paediatric cases of congenital choanal atresia are being discussed. Choanal atresia as a differential diagnosis should always be kept in mind in children presenting with respiratory distress in early neonatal period and in patients presenting with unilateral nasal discharge. Endoscopic surgical technique of choanal atresia repair along with stenting was done in all the 3 cases.

The use of the Sanuki airway™ in three patients with suspected difficult airway

The Sanuki airway is a single-use intubation oral airway designed for fiberoptic bronchoscope intubation. Sanuki airway has a bite block function and a wide lumen for the tracheal tube to pass through. Here, three cases are reported in which Sanuki airway was used for oral fiberoptic bronchoscope intubation. Case 1 is a patient who presented with reduced mouth opening and intraoral edema due to facial bone fracture. Case 2 is a patient who suffered from severe neck stiffness and had reduced mouth opening due to systemic psoriatic arthritis. Case 3 is a patient who suffered from multiple facial traumas and was in a full-stomach state. In all patients, advancing the tip of the bronchofiber into the larynx using Sanuki airway was possible under dexmedetomidine sedation, which contributed to the successful tracheal intubation. Using Sanuki airway may be considered an option for oral fiberoptic bronchoscope intubation in patients anticipated with difficult airways.

CPAP combined with oral appliance therapy reduces CPAP requirements and pharyngeal pressure swings in obstructive sleep apnea

Combined CPAP and oral appliance therapy has been suggested as an alternative for incomplete responders to oral appliance therapy. We used a novel oral appliance incorporating an oral airway together with CPAP to show that pharyngeal pressure swings were normalized at reduced CPAP levels. Our findings demonstrate that using CPAP and oral appliance together may be a beneficial alternative for incomplete responders to oral appliance therapy and intolerant CPAP users due to high-pressure requirements.

Is sore throat an underreported and under-estimated quality indicator for endoscopic procedures? Results from a large prospective cohort

Background and study aims Patients often develop sore throat after upper endoscopy procedures but there data are very limited on the magnitude of the problem. The aim of this study was to evaluate and identify independent risk factors of sore throat in patients undergoing endoscopy. Patients and methods Data were collected prospectively on consecutive outpatient endoscopy procedures performed at Cedars-Sinai Medical Center from October 2018 to February 2019. Procedure nurses collected pre-procedure, intra-procedure, and immediate post-procedure surveys including evaluation of sore throat (pain scale from 1 – 10). Significant univariate variables (P < 0.05) were entered into a multivariate logistic regression model. Results Data were collected on 715 patients. Four hundred seventy-two patients (mean age = 61 years, females = 53 %) were included in the analysis and 85 patients (18 %) experienced post-procedure sore throat. On univariate analysis, female gender, oral endoscopic ultrasound (EUS), oral double balloon enteroscopy (DBE), fellow involvement, throat suctioning, general anesthesia, oral airway, and prolonged procedure (> 30 minutes) were risk factors for sore throat (all P < 0.05). On the multivariate analysis, independent risk-factors for post-procedure sore throat were oral DBE (odds ratio [OR] 5.2), oral airway (OR 4.8), general anesthesia (OR 2.7), fellow involvement (OR 2.5), oral EUS (OR 2.4), and female gender (OR 2.0). Conclusions Contrary to popular belief, our study found that post-procedural sore throat is more common (18 %) than previously reported. Two types of endoscopic procedures, two anesthesia maneuvers, female gender, and fellow involvement were all independent risk factors. This is of particular concern for interventionalists who perform EUS and oral DBE as these patients are at higher risk for sore throat.