Drug-induced sleep endoscopy: A new gold standard for evaluating OSAS? Part II: Results

The Application of Ultrasound to Quantify Hyoid Motion During Drug-Induced Sleep Endoscopy

INTRODUCTION

The significance of hyoid dynamics in OSA pathophysiology remains unclear. Drug-induced sleep endoscopy (DISE) is often used for evaluating patients intolerant to positive airway pressure (PAP) therapy. We performed DISE with concurrent hyoid-focused ultrasonography to quantify hyoid dynamics during obstructive and non-obstructive breathing.

METHODS

A cross-sectional analysis from a prospective cohort of patients undergoing DISE with PAP titration (DISE-PAP) and hyoid-focused ultrasound was conducted. Hyoid ultrasound was performed during obstructive breathing, and non-obstructive breathing after PAP administration. Motion was quantified by generating displacement curves based on echo-tracking hyoid movement. The image analysis protocol for quantifying hyoid displacement was performed independently by two researchers, and reliability of measures was assessed. Univariate and multivariate regressions were performed for various clinical data and hyoid displacement during obstructive breathing.

RESULTS

Twenty patients met inclusion criteria. On average, the cohort was male (75%), elderly (65.9 ± 10 years), overweight (29.3 ± 3.99 kg/m2 ), and with moderate-to-severe OSA (29.3 ± 12.5 events/h). Mean hyoid displacement during obstructive breathing was 5.81 mm (±3.48). In all patients, hyoid displacement decreased after PAP administration (-3.94 mm [95% CI: -5.10, -2.78]; p < 0.0001). Inter-rater reliability for measures of hyoid displacement was excellent. After multivariate regression, hyoid displacement at baseline was associated with higher AHI (β [95% CI] = 0.18 [0.03, 0.33], p = 0.020).

CONCLUSION

During DISE, hyoid displacement is greater during obstructive breathing with significant variability amongst patients. Further, these ultrasonographic measurements had excellent intra- and inter-rater reliability. Additional, larger studies are needed to understand contributors to hyoid mobility.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:3221-3227, 2023.

The Effects of Anterior Palatoplasty and Functional Expansion Sphincter Pharyngoplasty on Voice Quality in Patients with Obstructive Sleep Apnea

OBJECTIVES

We aimed to examine the effects of anterior palatoplasty (AP) and functional expansion sphincter pharyngoplasty (FESP) on voice quality in patients with OSAS and to compare them with each other.

MERHODS

The study included 380 patients who came to the Otorhinolaryngology Clinic of our hospital with symptoms of snoring and sleep apnea between April 2020 and April 2022 and were referred to the sleep laboratory for polysomnography (PSG).Forty patients who met the study criteria and underwent AP and 26 patients who underwent FESP were included in the study. All surgeries were performed under general anesthesia by the same otolaryngologist within 1 month at the latest after sleep endoscopy. Acoustic voice analysis was performed using the Praat voice analysis program preoperatively and postoperatively at 6 months. F0, jitter, shimmer, and NHR (noise-to-harmonic ratio) were compared between the groups pre and postoperatively.

RESULTS

There were 20 females and 20 males in the AP group, 12 females and 14 males in the FESP group, There was no statistically significant difference in sex distribution between the groups (P = 0.952). The difference between the preop and postop F0, jitter, shimmer, and NHR in both the AP and FESP groups was statistically significant (P < 0.01). After AP and FESP surgeries, F0 values ​​increased, jitter, shimmer and NHR values ​​decreased (P < 0.01).F0, jitter, shimmer, and NHR changes were the greatest in the FESP group.(P < 0.01).

CONCLUSION

Positive changes in F0, jitter, shimmer, and NHR were greatest in the FESP group significantly. FESP surgery affects voice quality more than AP surgery in patients with OSAS.

Evaluation of a nasopharyngeal stent in patients with obstructive sleep-related breathing disorders

Objective

This study was performed to evaluate the therapeutic effect and diagnostic value of a novel nasopharyngeal stent (Naśtent; Corinium Medical Equipment Ltd., Cirencester, UK). The Naśtent is designed to stent palatal collapse in patients with sleep-related breathing disorders.

Methods

The study was conducted from 2018 to 2019. Patients who did not qualify for continuous positive airway pressure therapy underwent split-night examination with an inserted Naśtent for the first half of the night. The next morning, drug-induced sleep endoscopy (DISE) was performed.

Results

Of the 122 enrolled patients, 21 were excluded because of Naśtent intolerance (n = 14) or technically invalid examinations (n = 7). Among the remaining 101 patients, in correlation with DISE, the apnea–hypopnea index was significantly reduced in patients with palatal obstructions, mainly in those with anteroposterior collapse patterns. The Naśtent did not influence retrolingual or multilevel obstructions. Using a 40% reduction of the apnea–hypopnea index by the Naśtent as a cut-off value, 85.7% of soft palate obstructions were detected compared with DISE.

Conclusions

The Naśtent is a viable tool to reduce palatal obstructions, although it is not readily tolerated. It may also be helpful for diagnosis of sleep-related breathing disorders when DISE is unavailable.

Drug Induced Sleep Endoscopy Versus Awake Endoscopy in Retrolingual Obstruction Assessment in Obstructive Sleep Apnea Patients: A Comparative Study

ABSTRACT

The aim of this study is to evaluate the correlation of retrolingual obstruction determined by drug induced sleep endoscopy (DISE) and awake endoscopy evaluation of Muller maneuver (MM) and lingual tonsil hypertrophy (LTH) in patients with obstructive sleep apnea.A prospective cohort of 100 patients with obstructive sleep apnea who underwent DISE was assessed. The inclusion criteria were age between 18 and 70 years, and apnea-hypopnea index higher than 5. Friedman staging, LTH and MM were determined by awake endoscopy, as other physical findings. The authors evaluated the correlation of retrolingual obstruction determined by DISE using velum oropharynx tongue, epiglottis (VOTE) and nose, oropharynx, hypopharynx, larynx (NOHL) classification.When retrolingual MM was assessed, significant changes between awake and DISE were observed (P = 0.000). Conversely, Friedman stage had no significant changes to DISE retrolingual findings (P = 0.868). Analyzing LTH and DISE retrolingual findings according to NOHL and VOTE, if a cutoff value was established at 50%, DISE findings differ from awake: NOHL (P < 0.001) and VOTE (P = 0.004). Nevertheless, if a restrictive cutoff at 75% was attached, DISE findings were similar to awake: NOHL (P = 0.124) and VOTE (P = 0.123).This study demonstrates that awake endoscopy determining LTH and Friedman stage is a mild predictor of collapse at retrolingual level, showing significant correlation to DISE only when severe retrolingual collapse is present. Our findings suggest that in-office awake endoscopy may have certain predictive value to select surgical patients.

Evaluation of drug-induced sleep endoscopy as a tool for selecting patients with obstructive sleep apnea for maxillomandibular advancement

STUDY OBJECTIVES

(1) to investigate if DISE findings are predictive of surgical response for patients undergoing MMA for OSA; and (2) to investigate the predictive value of jaw thrust maneuver during DISE in terms of surgical response to MMA.

METHODS

A retrospective cohort study was conducted on patients with OSA who underwent a baseline polysomnography (PSG) and DISE followed by MMA and a 3-6-months follow-up PSG, between September 1, 2011 and September 30, 2020.

RESULTS

Sixty-four OSA patients (50 males [78.1%]; mean ± SD age = 51.7 ± 9.5 years; mean ± SD AHI = 49.0 ± 20.8 events/hour) were included. Thirty-nine patients were responders, and twenty-five were nonresponders. Adjusting for baseline characteristics and surgical characteristics (e.g., age, baseline AHI, degree of maxillary advancement), patients with complete anteroposterior epiglottic collapse had 0.239 times lower odds for response to MMA (95% confidence interval, 0.059-0.979; P = 0.047). No significant relationship was found between complete concentric velum collapse and MMA response. There was no statistically significant association between effect of jaw thrust maneuver during DISE on upper airway patency and treatment outcome of MMA.

CONCLUSIONS

This study indicates that DISE is a promising tool in order to identify patients who will or will not respond to MMA for treating OSA. Patients with complete anteroposterior epiglottic collapse may be less suitable candidates for MMA.

Obstructive sleep apnoea/hypopnoea syndrome: relationship with obesity and management in obese patients

Obstructive sleep apnoea/hypopnoea syndrome (OSAHS) is a disease characterised by upper airway obstruction during sleep, quite frequent in the general population, even if underestimated. Snoring, sleep apnoea and diurnal hypersomnia are common in these patients. Central obesity plays a key role: it reduces the size and changes the conformation of the upper airways, besides preventing lung expansion, with consequent reduction of lung volumes. Furthermore, obese people are also resistant to leptin, which physiologically stimulates ventilation; as a result, this causes scarce awakening during apnoea. OSAHS diagnosis is based on the combination of clinical parameters, such as apnoea/hypopnoea index (AHI), medical history, physical examination and Mallampati score. The first objective reference method to identify OSAHS is polysomnography followed by sleep endoscopy. Therapy provides in the first instance reduction of body weight, followed by continuous positive airway pressure (CPAP), which still remains the treatment of choice in most patients, mandibular advancement devices (MAD) and finally otolaryngology or maxillofacial surgery. Among surgical techniques, central is barbed reposition pharyngoplasty (BRP), used in the field of multilevel surgery.

Pediatric Airway Endoscopy: Recommendations of the Society for Pediatric Pneumology

For many decades, pediatric bronchoscopy has been an integral part of the diagnosis and treatment of acute and chronic pulmonary diseases in children. Rapid technical advances have continuously influenced the performance of the procedure. Over the years, the application of pediatric bronchoscopy has considerably expanded to a broad range of indications. In this comprehensive and up-to-date guideline, the Special Interest Group of the Society for Pediatric Pneumology reviewed the most recent literature on pediatric bronchoscopy and reached a consensus on a safe technical performance of the procedure.

Perioperative Management of the Patient With Obstructive Sleep Apnea: A Narrative Review

The prevalence of obstructive sleep apnea (OSA) has reached 1 billion people worldwide, implying significant risk for the perioperative setting as patients are vulnerable to cardiopulmonary complications, critical care requirement, and unexpected death. This review summarizes main aspects and considerations for the perioperative management of OSA, a condition of public health concern. Critical determinants of perioperative risk include OSA-related changes in upper airway anatomy with augmented collapsibility, diminished capability of upper airway dilator muscles to respond to airway obstruction, disparities in hypoxemia and hypercarbia arousal thresholds, and instability of ventilatory control. Preoperative OSA screening to identify patients at increased risk has therefore been implemented in many institutions. Experts recommend that in the absence of severe symptoms or additional compounding health risks, patients may nevertheless proceed to surgery, while heightened awareness and the adjustment of postoperative care is required. Perioperative caregivers should anticipate difficult airway management in OSA and be prepared for airway complications. Anesthetic and sedative drug agents worsen upper airway collapsibility and depress central respiratory activity, while the risk for postoperative respiratory compromise is further increased with the utilization of neuromuscular blockade. Consistently, opioid analgesia has proven to be complex in OSA, as patients are particularly prone to opioid-induced respiratory depression. Moreover, basic features of OSA, including intermittent hypoxemia and repetitive sleep fragmentation, gradually precipitate a higher sensitivity to opioid analgesic potency along with an increased perception of pain. Hence, regional anesthesia by blockade of neural pathways directly at the site of surgical trauma as well as multimodal analgesia by facilitating additive and synergistic analgesic effects are both strongly supported in the literature as interventions that may reduce perioperative complication risk. Health care institutions are increasingly allocating resources, including those of postoperative enhanced monitoring, in an effort to increase patient safety. The implementation of evidence-based perioperative management strategies is however burdened by the rising prevalence of OSA, the large heterogeneity in disease severity, and the lack of evidence on the efficacy of costly perioperative measures. Screening and monitoring algorithms, as well as reliable risk predictors, are urgently needed to identify OSA patients that are truly in need of extended postoperative surveillance and care. The perioperative community is therefore challenged to develop feasible pathways and measures that can confer increased patient safety and prevent complications in patients with OSA.

The Use of Propofol versus Dexmedetomidine for Patients Receiving Drug-Induced Sleep Endoscopy: A Meta-Analysis of Randomized Controlled Trials

The sedation outcomes associated with dexmedetomidine compared with those of propofol during drug-induced sleep endoscopy (DISE) remains unclear. Electronic databases (i.e., the Cochrane controlled trials register, Embase, Medline, and Scopus) were searched from inception to 25 December 2020 for randomized controlled trials (RCTs) that evaluated the sedation outcomes with dexmedetomidine or propofol in adult patients diagnosed with obstructive sleep apnea (OSA) receiving DISE. The primary outcome was the difference in minimum oxygen saturation (mSaO2). Five RCTs (270 participants) published between 2015 and 2020 were included for analysis. Compared with dexmedetomidine, propofol was associated with lower levels of mSaO2 (mean difference (MD) = -7.24, 95% confidence interval (CI) -12.04 to -2.44; 230 participants) and satisfaction among endoscopic performers (standardized MD = -2.43, 95% CI -3.61 to -1.26; 128 participants) as well as a higher risk of hypoxemia (relative ratios = 1.82, 95% CI 1.2 to 2.76; 82 participants). However, propofol provided a shorter time to fall asleep and a lower risk of failed sedation compared with dexmedetomidine. No significant difference was found in other outcomes. Compared with propofol, dexmedetomidine exhibited fewer adverse effects on respiratory function and provided a higher level of satisfaction among endoscopic performers but was associated with an elevated risk of failed sedation.

A systematic approach to the evaluation and management of obstructive sleep apnea: The Jefferson Protocol

Obstructive sleep apnea (OSA) has become increasingly prevalent in the United States. While continuous positive airway pressure (CPAP) therapy remains the gold standard for treatment, surgical intervention can enhance compliance and improve outcomes for those intolerant of CPAP. Since the majority of OSA patients have multilevel obstruction, it is critical that otolaryngologists understand each patient's pattern and anatomic level of obstruction before solidifying a treatment plan. This publication serves as a comprehensive review of evaluation, characterization, and management of OSA. Further, the authors outline their departmental algorithm for identifying ideal surgical candidates and tailoring corresponding surgical interventions.

Post-Operative Sleep Endoscopy with Target-Controlled Infusion After Palatopharyngoplasty for Obstructive Sleep Apnea: Anatomical and Polysomnographic Outcomes

INTRODUCTION

The findings of drug-induced sleep endoscopy (DISE) are not always correlated with the outcome of upper airway surgery for obstructive sleep apnea (OSA), and whether multilevel surgery is truly required in treating multilevel obstruction identified in preoperative DISE remains an issue. We attempted to compare DISE findings before and after palatopharyngoplasty in patients with OSA because changes in DISE may be beneficial to better understand polysomnographic and anatomical outcomes.

METHODS

This was a prospective cohort study for 34 patients with moderate to severe OSA who underwent palatopharyngoplasty at a tertiary care center from 2016 to 2018. We recorded the patients' demographic characteristics, procedures, and surgical outcomes and compared the preoperative and postoperative DISE staging patterns.

RESULTS

The apnea-hypopnea index (AHI) values of 34 adults improved significantly after surgery (40.6 ± 23.3 versus 25.6 ± 20.6, P < 0.001). The majority of patients, 26/34, had preoperative complete concentric collapse at the velum, and for most (20/26, 77%) there was a change of the collapse pattern into anteroposterior collapse postoperatively. Patients with postoperative velar collapse had higher follow-up AHI values than those who without (27.8 ± 21.9 versus 15.2 ± 7.7, P = 0.023). Patients with preoperative complete tongue base collapse had higher follow-up AHI values than did those with no or partial collapse (40.6 ± 21.0 versus 21.0 ± 18.6, P = 0.017). Patients with postoperative complete tongue base collapse also had higher follow-up AHI values than the others (42.7 ± 22.1 versus 18.5 ± 15.4, P = 0.001).

CONCLUSION

Palatopharyngoplasty could change the collapse pattern at the velum in most patients. Preoperative and postoperative complete tongue base collapse and postoperative velar collapse identified in TCI-DISE were associated with relatively poor outcomes.

The Emerging Role of Drug-Induced Sleep Endoscopy in the Management of Obstructive Sleep Apnea

Obstructive sleep apnea is a prevalent sleep disorder characterized by partial or complete obstruction of the upper airway. Continuous positive airway pressure is the first-line therapy for most patients, but adherence is often poor. Alternative treatment options such as mandibular advancement devices, positional therapy, and surgical interventions including upper airway stimulation target different levels and patterns of obstruction with varying degrees of success. Drug-induced sleep endoscopy enables the visualization of upper airway obstruction under conditions mimicking sleep. In the era of precision medicine, this additional information may facilitate better decision-making when prescribing alternative treatment modalities, with the hope of achieving better adherence and/or success rates. This review discusses the current knowledge and evidence on the role of drug-induced sleep endoscopy in the non-positive airway pressure management of obstructive sleep apnea.

OSAS and upper pharynx surgery: Does basilingual collapsus always rhyme with failure?

OBJECTIVE

Drug-induced-sedation endoscopy (DISE) has proved superior to awake clinical examination for diagnosis of upper-airway obstruction sites and surgical planning. Our question is: does multilevel obstruction on DISE systematically entail failure for surgery limited to the upper pharynx?

MATERIAL & METHODS

We conducted a retrospective single-center study in patients with obstructive sleep apnea syndrome (OSAS) treated by single-level surgery of the upper pharynx (tonsillectomy with or without pharyngoplasty). Preoperative assessment included polysomnography (PSG) and DISE. Surgical efficacy was assessed on postoperative PSG. Treatment response was defined by postoperative apnea-hypopnea index (AHI) <20 events/h with 50% reduction, and cure by AHI <10 (patients with preoperative AHI ≤10 being excluded). Efficacy was compared between groups without (group A) and with basilingual or laryngeal collapsus on DISE (group B).

RESULTS

We analyzed 63 patients, with mean preoperative AHI 33.8±17.9 events/h. The two groups (A, n=36; B, n=27) were clinically comparable. Postoperative PSG took place at a mean 8.5 ± 11.5 months. The success rate was 66.7% in group A (mean reduction in AHI, 57.3±36.2%) and 59.3% in group B (mean reduction, 53.9±39.2%). Cure rates were respectively 48.5% and 48.1%. There was no statistically significant difference between the two groups (P>0.1).

CONCLUSIONS

Oropharyngeal surgery can alleviate associated obstructive sites found on DISE in the lower pharynx, and step-by-step treatment shows efficacy equal to that of single-step multilevel surgery.

Comparison of Findings between Clinical Examinations and Drug-Induced Sleep Endoscopy in Patients with Obstructive Sleep Apnea Syndrome

The Velum, Oropharynx, Tongue base and Epiglottis (VOTE) classification on drug-induced sleep endoscopy (DISE) is used widely for obstructive sleep apnea (OSA) syndrome, though research into comparative physical examinations with VOTE on DISE is still limited. The aim of this study was to evaluate the relationship between the findings of physical examinations and DISE in patients with OSA. Fifty-five patients with OSA were enrolled in this retrospective study. All of the patients received clinical explorations including a Brodsky classification, a modified Mallampati score (MMS), a modified Friedman’s staging system, and a Muller’s test. Drug-induced sleep endoscopy was further evaluated in the operating room. There were significant relationships between Brodsky classification, modified Friedman’s staging system, Muller’s test and oropharynx collapse during DISE (p < 0.05). Brodsky classification, MMS, modified Friedman’s staging system and retropalatal lateral-to-lateral (L–L) collapse of Muller’s test were significantly correlated with VOTE count (p < 0.05). The concordance between VOTE under DISE and Brodsky classification or modified Friedman’s staging system was moderate. In contrast, the concordance between VOTE under DISE and MMS or Muller’s test was slight. The study revealed that Brodsky classification and Friedman staging had a significant relationship with DISE on the velum and oropharynx, but the level of tongue base is uncertain between DISE and MMS. Correlation of awake evaluation of tongue base is still not correlated to the DISE findings. Pre-treatment evaluation of DISE is still warranted.

Can drug-induced sleep endoscopy improve the success rates of tongue base surgery?

Background

The purpose of this study was to determine the therapeutic value of drug-induced sleep endoscopy (DISE) by comparing the outcomes of tongue base surgery based on Muller’s maneuver (MM) and those based on DISE in obstructive sleep apnea (OSA) patients.

Methods

Ninety-five patients who underwent the tongue base surgery in combination with palatal surgery for OSA at a tertiary referral hospital between March 2012 and March 2019 were enrolled in this retrospective comparative study. Forty-seven patients underwent MM for surgical decision and 48 patients underwent DISE in addition to MM for surgical decision. Surgical success was defined according to the Sher criteria (postoperative apnea-hypopnea index [AHI] < 20/h and ≥ 50% reduction in preoperative AHI), and AHI improvement (%) was defined as (preoperative AHI-postoperative AHI) × 100/preoperative AHI. For comparison between the MM and DISE groups, p-values were calculated using independent or paired t-tests for continuous variables and using chi-square test for categorical variables.

Results

By comparing the results of MM and DISE, consensus on the tongue base level showed insignificant concordance (kappa = 0.017, p = 0.865), whereas that on the oropharynx level showed fair agreement (kappa =0.241, p = 0.005). AHI, supine AHI, rapid eyeball movement (REM) AHI, non-REM AHI, and nadir oxygen saturation were all significantly improved after the tongue base surgery in both groups. The MM group showed a significant improvement in the Epworth sleepiness scale after the tongue base surgery (p = 0.014), whereas the DISE group did not (p = 0.165). However, there was no significant difference in the AHI improvement (MM group = 47.0 ± 32.0, DISE group = 48.3 ± 35.4, p = 0.852) and surgical success (MM group = 42.6%, DISE group = 45.8%, p = 0.748) between the groups. Tonsil grade (p < 0.05) and occlusion at the oropharynx lateral wall (p = 0.031) were significantly related to surgical success in the MM group.

Conclusions

In the judgment of the tongue base surgery, MM and DISE findings showed poor agreement. DISE might affect the surgical decision on the tongue base surgery in OSA patients; however, there was a lack of evidence regarding the superiority of DISE over MM with respect to the surgical outcomes.

Drug-Induced Sleep Endoscopy: Clinical Application and Surgical Outcomes

The visualization of the level and pattern of apnea and hypopnea events is of pivotal importance in the diagnosis and therapeutic decision-making for sleep-disordered breathing (SDB). There are numerous techniques available to assess upper airway obstruction, which include imaging, acoustic analysis, pressure transducer recording, and endoscopic evaluation. Drug-induced sleep endoscopy (DISE) is a diagnostic tool that allows the dynamic, three-dimensional evaluation of the patterns of vibration and collapse of the upper airway of SDB patients. DISE may change the initial surgical planning in a high percentage of cases. A universally accepted and methodologically standardized DISE could provide significant insight into its role to improve surgical outcomes. However, up to now the ideal DISE protocol remains an open question.

Society of Anesthesia and Sleep Medicine Guideline on Intraoperative Management of Adult Patients With Obstructive Sleep Apnea

The purpose of the Society of Anesthesia and Sleep Medicine Guideline on Intraoperative Management of Adult Patients With Obstructive Sleep Apnea (OSA) is to present recommendations based on current scientific evidence. This guideline seeks to address questions regarding the intraoperative care of patients with OSA, including airway management, anesthetic drug and agent effects, and choice of anesthesia type. Given the paucity of high-quality studies with regard to study design and execution in this perioperative field, recommendations were to a large part developed by subject-matter experts through consensus processes, taking into account the current scientific knowledge base and quality of evidence. This guideline may not be suitable for all clinical settings and patients and is not intended to define standards of care or absolute requirements for patient care; thus, assessment of appropriateness should be made on an individualized basis. Adherence to this guideline cannot guarantee successful outcomes, but recommendations should rather aid health care professionals and institutions to formulate plans and develop protocols for the improvement of the perioperative care of patients with OSA, considering patient-related factors, interventions, and resource availability. Given the groundwork of a comprehensive systematic literature review, these recommendations reflect the current state of knowledge and its interpretation by a group of experts at the time of publication. While periodic reevaluations of literature are needed, novel scientific evidence between updates should be taken into account. Deviations in practice from the guideline may be justifiable and should not be interpreted as a basis for claims of negligence.

Moderate OSAS and turbinate decongestion: surgical efficacy in improving the quality of life and compliance of CPAP using Epworth score and SNOT-20 score

SUMMARY

Drug-induced sleep endoscopy (DISE) is an important procedure in diagnostic pathway of patients affected by moderate OSAS. However, the Italian National Health System does not provide any compatible Diagnosis-related-group (DRG) code codification for DISE, which makes it impossible to obtain regional reimbursement. In order to overcome this problem, DISE is usually associated with other codified surgical procedures. The aim of our study is to assess the association of turbinate decongestion (TD) and DISE in order to combine in a single operating session diagnostic and therapeutic procedures. The objective of our work is to assess the role of nasal surgery on symptoms of moderate OSA. Recent studies have confirmed that isolated nasal surgery improves quality of life (QOL), but not the apnoea hypopnoea index (AHI) during polygraph registration. We enrolled 30 patients, aged between 29 and 64 years (mean 50.53 ± 9.20), 26 males and 4 females, with a mean BMI of 26.07 ± 2.81 kg/m², who were affected by moderate OSAS. All patients underwent otolaryngologycal pre-operative evaluation, home respiratory polygraph and subjective evaluation through Sino-Nasal-Outcome Test (SNOT-20) and Epworth Sleepiness Scale (ESS). During the same surgery session, they underwent DISE and TD. Patients were re-evaluated six months later using the same questionnaires. We observed a significant improvement (p #x003C; 0.05) in both the mean ESS index (6.03 ± 2.75 vs 4.16 ± 4.63) and total SNOT score (22.53 ± 12.16 vs 13.23 ± 10.82). Significant differences (p #x003C; 0.05) were also identified for partial SNOT questions 1-11 (9.1 ± 5.11 vs 6.13 ± 4.12) and 11-20 (13.36 ± 10.20 vs 7.13 ± 9.644). The results of the present study confirm that TD alone can improve sleepiness, QOL and nasal symptoms. Thus, in absence of a National Health System recognition for DISE, the association of this procedure with TD can be useful for diagnostic and therapeutic management of OSAS, improving CPAP compliance and adherence, reducing sleepiness, ameliorating nasal symptoms and therefore QOL.

A Novel Non-invasive Approach for Measuring Upper Airway Collapsibility in Mice

Introduction: Invasive procedures were previously developed for measuring pharyngeal collapsibility in rodents during expiration, when declining neuromuscular activity makes the airway unstable. We developed a non-invasive approach for streamlining collapsibility measurements by characterizing responses in physiologic markers of dynamic expiratory airflow obstruction to negative nasal pressure challenges. Methods: Anesthetized mice were instrumented to monitor upper airway pressure-flow relationships with head-out plethysmography while nasal pressure was ramped down from ~ +5 to -20 cm H₂O over several breaths. Inspiratory and expiratory flow, volume, and timing characteristics were assessed breath-wise. Pcrit was estimated at transitions in expiratory amplitude and timing parameters, and compared to gold standard P_CRIT measurements when nasal and tracheal pressures diverged during expiration. Predictions equations were constructed in a development data set (n = 8) and applied prospectively to a validation data set (n = 16) to estimate gold standard P_CRIT. Results: The development data demonstrated that abrupt reversals in expiratory duration and tidal volume during nasal pressure ramps predicted gold standard P_CRIT measurements. After applying regression equations from the development to a validation dataset, we found that a combination of expiratory amplitude and timing parameters proved to be robust predictors of gold standard P_CRIT with minimal bias and narrow confidence intervals. Conclusions: Markers of expiratory airflow obstruction can be used to model upper airway collapsibility, and can provide sensitive measures of changes in airway collapsibility in rodents. This approach streamlines repeated non-invasive P_CRIT measurements, and facilitates studies examining the impact of genetic, environmental, and pharmacologic factors on upper airway control.

The role of drug-induced sleep endoscopy: predicting and guiding upper airway surgery for adult OSA patients

PURPOSE

Obstructive sleep apnea (OSA) is a common sleep disorder that can be corrected with upper airway surgery. Prior to surgery, drug-induced sleep endoscopy (DISE) is routinely used to evaluate obstruction sites and severity. Evidence suggests that the findings of DISE may relate to the final surgical outcome. Therefore, we evaluated the ability of drug-induced sleep endoscopy to predict the final effect of upper airway surgery and potentially to guide surgical treatment decision-making.

METHODS

A retrospective analysis was conducted on 85 adult patients with OSA (50 men with mean apnea-hypopnea index [AHI] 30 ± 15 events/h) who underwent DISE followed by tonsillectomy, uvulopalatopharyngoplasty (UPPP), or a combination of the two. Surgery outcome was evaluated at follow-up by polysomnography. Success response to surgery was defined as a postoperative value of the AHI< 20 events/h and more than 50% postoperative reduction of AHI.

RESULTS

Of the 85 patients evaluated, 48 (53%) were responders. DISE revealed significant differences between the two groups. Specifically, complete circumferential collapse at the velum and complete anterior-posterior collapse at the tongue base occurred at higher frequencies in nonresponders. In contrast, the presence of grade 3-4 tonsillar hypertrophy and anterior-posterior mild/partial collapse at the velum were positively associated with responders.

CONCLUSIONS

Our results suggest that DISE may help predict the final outcome of tonsillectomy, UPPP, or a combination of the two in adult patients with OSA. The use of DISE shows potential to guide treatment decisions for individual patients with OSA.

Drug-Induced Sleep Computed Tomography-Directed Upper Airway Surgery for Obstructive Sleep Apnea: A Pilot Study

OBJECTIVE

A surgical response to upper airway (UA) surgery for obstructive sleep apnea (OSA) depends on adequate correction of collapsible sites in the UA. This pilot study aimed to examine the surgical response to UA surgery directed by drug-induced sleep computed tomography (DI-SCT) for OSA.

STUDY DESIGN

Prospective case series.

SETTING

Tertiary referral center.

SUBJECTS AND METHODS

This study recruited 29 OSA patients (median age, 41 years; median body mass index, 26.9 kg/m²) who underwent single-stage DI-SCT-directed UA surgery between October 2012 and September 2014. DI-SCT was performed with propofol for light sedation with a bispectral monitor before and after UA surgery. Nonresponders were defined as those with a reduction in apnea-hypopnea index <50% after 6 months following UA surgery.

RESULTS

DI-SCT showed that 28 (97%) patients had collapses at multiple sites, all of whom underwent multilevel UA surgery accordingly. The apnea-hypopnea index decreased from 53.6 to 26.8 ( P < .001). There were 18 (62%) nonresponders and 11 (38%) responders. Multiple-site collapses could not predict surgical response ( P > .99). The nonresponders had significant improvements in velopharyngeal, oropharyngeal lateral wall, and tongue collapses (all P < .05), whereas the responders had significant improvements in velopharyngeal and oropharyngeal lateral wall collapses (both P ≤ .05).

CONCLUSION

Despite multilevel OSA surgery, residual UA obstruction in nonresponders likely occurs due to multiple mechanisms. DI-SCT may help to elucidate the reasons for a nonresponse.

Drug-induced sleep endoscopy: from obscure technique to diagnostic tool for assessment of obstructive sleep apnea for surgical interventions

PURPOSE OF REVIEW

Provide a practical update on drug-induced sleep endoscopy (DISE) for anesthesia providers, which can also serve as a reference for those preparing to establish a DISE program.

RECENT FINDINGS

New developments in surgical approaches to OSA and the growing global incidence of the condition have stimulated increased interest and demand for drug-induced sleep endoscopy. New techniques include transoral robotic surgery and hypoglossal nerve stimulation. Recent DISE literature has sought to address numerous debates including relevance of DISE findings to those during physiologic sleep and the most appropriate depth and type of sedation for DISE. Propofol and dexmedetomidine have supplanted midazolam as the drugs of choice for DISE. Techniques based on pharmacokinetic models of propofol are superior to empiric dosing with regard to risk of respiratory compromise and the reliability of dexmedetomidine to achieve adequate conditions for a complete DISE exam is questionable.

SUMMARY

The role of DISE in surgical evaluation and planning for treatment of OSA continues to develop. Numerous questions as to the optimal anesthetic approach remain unanswered. Multicenter studies that employ a standardized approach using EEG assessment, pharmacokinetic-pharmacodynamic modelling, and objectively defined clinical endpoints will be helpful. There may be benefit to undertaking DISE studies in non-OSA patients.

Imaging of adult obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is characterised by recurrent upper airway collapse during sleep resulting in chronic and repetitive hypoxia, hypercapnia, subsequent arousal and fragmented sleep. Symptoms are insidious and diagnosis is usually delayed. Moderate to severe OSA has serious health implications with significant increase in all causes of mortality in patients with the condition as compared with unaffected individuals. The prevalence of OSA in the 30-70 year age group is estimated at 27% of males and 11% of females and it increases with age. 80% of affected individuals are obese and as obesity rates rise, so has the prevalence of OSA. An overnight polysomnogram (PSG) is required for a definitive diagnosis of OSA. Imaging has played a fundamental role in the evaluation of the anatomical factors associated with recurrent upper airway collapse and the pathogenesis of OSA. The upper airway is frequently imaged by radiologists, providing an opportunity to detect features that are strongly associated with unsuspected OSA and to raise the possibility of this diagnosis. The gold standard of treatment is continuous positive airway pressure (CPAP) which acts as a pneumatic splint for the upper airway. However, efficacy is frequently limited by poor tolerance; clinicians and patients are increasingly opting for one of a range of surgical procedures. Dedicated imaging protocols can be performed for evaluation of the upper airway to aid surgical planning.