Physiology of Sleep Disordered Breathing

Monitoring of Home Respiratory Polygraphy During Mandibular Distraction Osteogenesis Succeeded by LeFort I Osteotomy in Adult Patients With Obstructive Sleep Apnea

BACKGROUND

Bilateral internal ramus distraction (BIRD) is now part of select protocols for treating obstructive sleep apnea (OSA). Introducing a home monitoring protocol offers a valuable alternative to overnight laboratory polysomnography (PSG).

PURPOSE

The purpose of this study was to evaluate and compare OSA parameters obtained via home respiratory polygraphy (HRP) and hospital PSG in a cohort of patients undergoing mandibular distraction for OSA management.

STUDY DESIGN, SETTING, SAMPLE

Hospital Universitario La Princesa (Madrid) researchers conducted a prospective cohort study with patients diagnosed with moderate (apnea-hypopnea index (AHI) = 15 to 30) to severe (AHI>30) OSA undergoing BIRD followed by LeFort maxillary osteotomy. Exclusion criteria were as follows: severe systemic diseases, central apneas, smoking, poor dental hygiene, or prior OSA interventions.

PREDICTOR VARIABLE

The predictor variable was PSG and HRP techniques.

MAIN OUTCOME VARIABLES

The main outcome variable comprises a collection of OSA parameters, including the AHI, oxygen desaturation index (ODI), and time spent below 90% oxygen saturation (T90). These data were measured both before and after distraction, as well as after 6 mm, 9 mm, and 12 mm of mandibular distraction.

COVARIATES

The covariates were age, sex, cardiovascular risk parameters, and the Epworth sleepiness scale.

ANALYSES

Pearson's correlation analyzed AHI, ODI, and T90 values from PSG and HRP. Wilcoxon Signed Rank-Sum Test compared 2 distraction stages, and the Friedman Test evaluated 3 stages (P < .05). Multiple regression analysis assessed if covariates were independent risk factors for postoperative persistent OSA.

RESULTS

The study included 32 patients (25% with moderate and 75% with severe OSA). Final AHI was 10.9 ± 8.9 (events/hour) with HRP, compared to 15.2 ± 13.4 with PSG (r = 0.7, P < .05). ODI was 9.0 ± 8.1 (des/h) with HRP and 8.7 ± 9.5 with PSG (r = 0.85, P < .05). T90 was 1.6 ± 2.2 with HRP and 1.3 ± 3.0 with PSG (r = 0.6, P < .05). Based on HRP data, AHI improved from D1 (34.0 ± 19.5) to D2 (20.8 ± 14.1) and D3 (12.5 ± 10.4) (P < .05). ODI decreased from D1 (26.1 ± 19.0) to D2 (16.0 ± 12.6) and D3 (9.4 ± 8.8) (P < .05). T90 reduced from D1 (8.2 ± 12.6) to D2 (4.1 ± 5.2) and D3 (1.9 ± 2.8) (P < .05). Multiple regression analysis of comorbidities produced nonsignificant results.

CONCLUSION AND RELEVANCE

Monitoring BIRD through HRP has demonstrated efficacy in yielding results that align with PSG.

Types of Epiglottic Collapse in Breathing Sleep Disorder and Their Impact in Clinical Practice

Introduction  Obstructive sleep apnea (OSA) is a severe form of sleep-disordered breathing (SDB) that is strongly correlated with comorbidities, in which epiglottic collapse (EC) and other contributing factors are involved. Objectives  To evaluate the occurrence of EC in OSA patients through drug-induced sleep endoscopy (DISE) and to determine the factors contributing to EC. Methods  A retrospective study of 37 adult patients using medical history. Patients were assessed for laryngopharyngeal reflux (LPR) and lingual tonsil hypertrophy (LTH) using reflux symptom index and reflux finding score (RFS); for OSA using polysomnography, and for airway collapse through DISE. An independent t -test was performed to evaluate risk factors, including the involvement of three other airway structures. Results  Most EC patients exhibited trap door epiglottic collapse (TDEC) (56.8%) or pushed epiglottic collapse (PEC) (29.7%). Lingual tonsil hypertrophy, RFS, and respiratory effort-related arousal (RERA) were associated with epiglottic subtypes. Laryngopharyngeal reflux patients confirmed by RFS (t(25) = -1.32, p  = 0.197) tended to suffer PEC; LTH was significantly associated (X2(1) = 2.5, p  = 0.012) with PEC (odds ratio [OR] value = 44) in grades II and III LTH patients; 11 of 16 TDEC patients had grade I LTH. Pushed epiglottic collapse was more prevalent among multilevel airway obstruction patients. A single additional collapse site was found only in TDEC patients. Conclusion  Laryngopharyngeal reflux causes repetitive acid stress toward lingual tonsils causing LTH, resulting in PEC with grade II or III LTH. Trap door epiglottic collapse requires one additional structural collapse, while at least two additional collapse sites were necessary to develop PEC. Respiratory effort-related arousal values may indicate EC.

Oxidative Stress in Obstructive Sleep Apnea Syndrome: Putative Pathways to Hearing System Impairment

INTRODUCTION

OSAS is a disease that affects 2% of men and 4% of women of middle age. It is a major health public problem because untreated OSAS could lead to cardiovascular, metabolic, and cerebrovascular complications. The more accepted theory relates to oxidative stress due to intermittent hypoxia, which leads, after an intense inflammatory response through multiple pathways, to endothelial damage. The objective of this study is to demonstrate a correlation between OSAS and hearing loss, the effect of the CPAP on hearing function, and if oxidative stress is also involved in the damaging of the hearing system.

METHODS

A review of the literature has been executed. Eight articles have been found, where seven were about the correlation between OSAS and the hearing system, and only one was about the CPAP effects. It is noted that two of the eight articles explored the theory of oxidative stress due to intermittent hypoxia.

RESULTS

All studies showed a significant correlation between OSAS and hearing function (p < 0.05).

CONCLUSIONS

Untreated OSAS affects the hearing system at multiple levels. Oxidative stress due to intermittent hypoxia is the main pathogenetic mechanism of damage. CPAP has no effects (positive or negative) on hearing function. More studies are needed, with the evaluation of extended high frequencies, the execution of vocal audiometry in noisy environments, and the evaluation of potential biomarkers due to oxidative stress.

Effectiveness of functional orthopedic appliances as an alternative treatment among children and adolescents with obstructive sleep apnea: Systematic review and meta-analysis

INTRODUCTION

The objective here was to review the efficacy of functional jaw orthopedic appliances for treating children/adolescents with obstructive sleep apnea (OSA), through correlating the apnea/hypopnea index (AHI) and oxygen saturation (SaO₂) in polysomnography (PSG), in addition to questionnaire scores from the obstructive sleep apnea-18 (OSA-18).

METHODS

The PRISMA 2020 guidelines¹ were followed. A search was conducted in October 2021, with updating to May 2022, in the MEDLINE/PubMed, BVS (LILACS/BBO), ISI, SciELO (Web of Science), COCHRANE, EMBASE, SCOPUS and WHO databases and the gray literature. Data selection and extraction were performed by two independent reviewers, with Cohen kappa testing. All articles included in the meta-analyses showed good quality and low risk of bias. Statistical analyses were performed in the "R" software, using means with standard deviations, and differences in the means were represented graphically in forest plots. Heterogeneity was tested using I², in random-effect models.

RESULTS

From before to after treatment, treated individuals showed improved AHI, SaO₂ and OSA-18 scores². Comparing treated individuals and controls, AHI decreased in treated individuals and increased in controls. For SaO₂, the increase in treated individuals was greater than in controls. For OSA-18, daytime/nighttime symptoms decreased in treated individuals and increased in controls.

CONCLUSION

Functional jaw orthopedic appliances are appropriate and effective for children/adolescents with OSA whose etiology is deficient maxillomandibular growth and development. Functional jaw orthopedics treats the form and function of the stomatognathic system, thereby enhancing quality of life.

PROSPERO REGISTRATION PROTOCOL

CRD42021253341.

Effect of orthopedic and functional orthodontic treatment in children with obstructive sleep apnea: A systematic review and meta-analysis

Orthodontic treatment is suggested in growing individuals to correct transverse maxillary deficiency and mandibular retrusion. Since, as a secondary effect, these orthodontic procedures may improve pediatric obstructive sleep apnea (OSA), this systematic review assessed their effects on apnea-hypopnea index (AHI) and oxygen saturation (SaO2). Twenty-five (25) manuscripts were included for qualitative synthesis, 19 were selected for quantitative synthesis. Five interventions were analyzed: rapid maxillary expansion (RME, 15 studies), mandibular advancement (MAA, five studies), myofunctional therapy (MT, four studies), and RME combined with MAA (one study). RME produced a significant AHI reduction and minimum SaO2 increase immediately after active treatment, at six and 12 months from baseline. A significant AHI reduction was also observed six and 12 months after the beginning of MAA treatment. MT showed positive effects, with different protocols. In this systematic review and meta-analysis of data from mainly uncontrolled studies, interceptive orthodontic treatments showed overall favorable effects on respiratory outcomes in pediatric OSA. However, due to the low to very low level of the body evidence, this treatment cannot be suggested as elective for OSA treatment. An orthodontic indication is needed to support this therapy and a careful monitoring is required to ensure positive improvement in OSA parameters.

Predicting the presence and severity of obstructive sleep apnea based on mandibular measurements using quantitative analysis of facial profiles via three-dimensional photogrammetry

BACKGROUND

In obstructive sleep apnea (OSA), the upper airway is obstructed during sleep due to obesity and/or posterior collapse of the tongue root. Maxillofacial morphological abnormalities increase the risk of OSA in the Asian population. This study sought to elucidate whether three-dimensional (3D) photogrammetry measurements correlate with the severity of OSA irrespective of sex and degree of obesity.

METHODS

A prospective pilot study was performed, in which 37 consecutive adult patients (M/F = 28/9) underwent polysomnography and 3D photogrammetry in the supine position for the diagnosis of OSA. Measurements obtained from 3D photogrammetry included mandibular width (Mw), mandibular length (Ml), mandibular depth (Md), mandibular width-length angle (Mwla), and mandibular area (Ma). The effects of sex and body mass index (BMI) on the measurements and their association with the apnea-hypopnea index (AHI) were statistically analyzed. The inter-rater reliability of the measurements was evaluated using intraclass correlation coefficients (ICC).

RESULTS

Mwla (R = 0.73, p < 0.01), Mw (R = 0.39, p < 0.05), and Md (R = -0.34, p < 0.05) were significantly correlated with the severity of OSA. On multivariate analysis, Mwla (p < 0.01) and Md (p < 0.05) remained independent factors for AHI after adjusting for sex, age, BMI, and neck circumference. In addition, diagnosability analysis revealed that Mwla was useful for identifying the presence of OSA (AHI ≥5) (cutoff: 78.6°, sensitivity: 0.938, specificity: 0.800, area under the curve: 0.931). The ICC was >0.9, showing high reliability.

CONCLUSIONS

This study suggests that Mwla measured using 3D photogrammetry can predict the presence of OSA and correlates with the severity of OSA, independent of obesity and sex.

Aerodynamics Analysis of the Impact of Nasal Surgery on Patients with Obstructive Sleep Apnea and Nasal Obstruction

OBJECTIVE

The purpose of this study was to evaluate the effects of nasal surgery on airflow characteristics in patients with obstructive sleep apnea (OSA) by comparing the alterations of airflow characteristics within the nasal and palatopharyngeal cavities.

METHODS

Thirty patients with OSA and nasal obstruction who underwent nasal surgery were enrolled. A pre- and postoperative 3-dimensional model was constructed, and alterations of airflow characteristics were assessed using the method of computational fluid dynamics. The other subjective and objective clinical indices were also assessed.

RESULTS

By comparison with the preoperative value, all postoperative subjective symptoms statistically improved (p < 0.05), while the Apnea-Hypopnea Index (AHI) changed little (p = 0.492); the postoperative airflow velocity and pressure in both nasal and palatopharyngeal cavities, nasal and palatopharyngeal pressure differences, and total upper airway resistance statistically decreased (all p < 0.01). A significant difference was derived for correlation between the alteration of simulation metrics with subjective improvements (p < 0.05), except with the AHI (p > 0.05).

CONCLUSION

Nasal surgery can decrease the total resistance of the upper airway and increase the nasal airflow volume and subjective sleep quality in patients with OSA and nasal obstruction. The altered airflow characteristics might contribute to the postoperative reduction of pharyngeal collapse in a subset of OSA patients.

Preliminary results on the impact of simultaneous palatal expansion and mandibular advancement on the respiratory status recorded during sleep in OSAS children

INTRODUCTION

The study aimed to evaluate the evolution of the respiratory status during sleep of OSAS children treated with a custom-made device combining maxillary expansion and mandibular advancement.

MATERIAL AND METHODS

Sleep studies were performed before and after the treatment for 103 children presenting an initial OSAS and Class II malocclusion. Sleep questionnaires were also addressed to parents several years after the end of the treatment to evaluate its long-term effects.

RESULTS

After nine months of treatment, the sleep breathing quality significantly improved: the Apnea/Hypopnea Index systematically decreased ≤5. According to the sleep questionnaires results, 84% of the patients did not show any loud or troubled breathing several years after the end of the treatment.

DISCUSSION

Simultaneous maxillary expansion and mandibular advancement induced an increase of the oral space in the three spatial dimensions, helping in the significant improvement of the OSAS symptoms, with long-terms effects on the sleep breathing quality.

The status of cephalometry in the prediction of non-CPAP treatment outcome in obstructive sleep apnea patients

Obstructive sleep apnea syndrome (OSAS) is the most common sleep disordered breathing disorder (SDB) in adults and is characterized by a recurrent partial or complete collapse of the upper airway during sleep. This can be caused by many factors, sometimes interacting, such as skeletal malformations, soft tissue crowding, respiratory instability and the various effects of aging, obesity and gender that dictate craniofacial and upper airway anatomy. Research has demonstrated that the majority of patients exhibit at least one anatomical component such as retrognathia or a narrow posterior airway space that predisposes to the development of OSAS. Within the predisposing elements for OSAS many seem to point to anatomical characteristics. A standardized and relatively simple radiologic technique to evaluate anatomical craniofacial relationships is cephalometry. This has been used already for a long time in orthodontics, but is now gradually being introduced in OSAS treatment to envisage optimal treatment selection as well as to predict treatment outcomes. The purpose of the present review is to evaluate the contribution of cephalometry in the prediction of outcomes from OSAS treatments that depend on the upper airway morphology in their mechanisms of action such as oral appliances that advance the mandible as well as various surgical methods. In addition, an overview of imaging modalities and methods that currently are being used in cephalometric analysis in OSAS patients is provided. The findings indicate that isolated cephalometric parameters cannot be used to reliably predict treatment outcomes from mandibular advancement devices and surgical methods for OSAS. Extreme or outlying values of cephalometric parameters may rather be used as contra-indicators or 'red flags' instead of predictors.

The effect of the prone sleeping position on obstructive sleep apnoea

CONCLUSIONS

Prone positioning reveals promising results in improving the apnoea-hypopnoea index (AHI) and oxygen desaturation index (ODI) in patients with obstructive sleep apnoea (OSA).

OBJECTIVE

To evaluate the effect of the prone position on OSA.

METHODS

Thirty-two patients with mild to severe OSA were included in the study. This was a two-night study to evaluate the effect of the prone position on OSA; a first night in a normal bed with optional positioning and a second night on a mattress and pillow facilitating prone positioning.

RESULTS

A total of 27 patients, 22 males and 5 females, with a mean age of 51 years, 15 patients with positional OSA (POSA) and 12 patients with non-POSA with a total median AHI of 23 (min 5, max 93) completed the study protocol. The median AHI decreased from 23 to 7 (p < 0.001) and the median ODI from 21 to 6 (p < 0.001). The median time spent in the supine position decreased from 142 to <1 min (p < 0.0001) and the median time in the prone position increased from <1 to 330 min (p < 0.0001). In all, 17 of 27 patients (63%) were considered to be responders to prone positioning, 12 of 15 (80%) with POSA and 5 of 12 (42%) with non-POSA. Five patients did not complete the study protocol due to sleep time <4 h.

Anesthetic Dilemmas for Dynamic Evaluation of the Pediatric Upper Airway

Sleep cine magnetic resonance imaging and drug-induced sleep endoscopy are currently used to examine the patterns of dynamic airway collapse in children with obstructive sleep apnea. Providing anesthesia that mimics physiologic sleep in these children is a challenge but is critical for accurate interpretation of the airway evaluation. Anesthetic agents might negatively affect the upper airway evaluation. The anesthetic technique in these patients must be tailored to improve patient safety and obtain optimal study. This review focuses on the periprocedural challenges and anesthetic management of children presenting for dynamic evaluation of the upper airway.

Sleep disordered breathing and airway disease in primary ciliary dyskinesia

BACKGROUND AND OBJECTIVE

Sleep-disordered breathing (SDB) may develop in primary ciliary dyskinesia (PCD), leading to these diseases worsening one another.

METHODS

Sixteen stable PCD patients (4.9-17.2 years) and 42 controls underwent overnight respiratory polysomnography (rPSG) and Sleep Disturbances Scale for Children (SDSC). In PCD we assessed nasal endoscopy, pulmonary function tests and chest high-resolution computed tomography (HRCT).

RESULTS

Compared with controls, PCD had higher obstructive apnoea (4.7 vs 0.2, P < 0.001), central apnoea (0.8 vs 0.2, P < 0.001), hypopnoea (1.8 vs 0.2, P < 0.001), apnoea-hypopnoea (7.8 vs 0.6, P < 0.001), oxygen desaturation indexes (ODI; 0.7 vs 0.2, P = 0.002), and mean oxygen desaturation (4% vs 1%, P < 0.001), while mean and nadir oxygen saturation (97.1% vs 98.1, P < 0.001) (93% vs 97.2%, P < 0.001) were lower, respectively. In PCD, SDSC was unrelated to rPSG (P > 0.05), with total score and subscores of disorders in initiating and maintaining sleep, and sleep-wake transition lower than controls. PCD patients had chronic rhinosinusitis (100%) and adenoidal hypertrophy (50%). Total HRCT score was 7 (range 0-14). ODI correlated with functional residual capacity (r = 0.8, P = 0.02), total HRCT (r = 0.6, P = 0.03) and peribronchial thickening scores (r = 0.7, P = 0.02). Oxygen saturation was associated with bronchiectasis severity score (r = -0.6, P = 0.02).

CONCLUSIONS

PCD's parents may underestimate SDB. As nocturnal desaturation is associated with lung function and structure abnormalities, SDB may significantly contribute to pulmonary morbidity.

Prevention of perioperative and anesthesia-related complications in facial cosmetic surgery

Although office-based anesthesia for facial cosmetic surgery remains remarkably safe, no anesthesia or sedation performed outside the operating room should be considered minor. Proper organization, preparation, and patient selection, close collaboration with the surgeon, and expert and effective anesthesia care will increase patient safety and improve perioperative outcomes and patient satisfaction. This article presents a comprehensive overview of anesthesia in terms of facial plastic surgery procedures, beginning with a broad review of essentials and pitfalls of anesthesia, followed by details of specific anesthetic agents, their administration, mechanism of action, and complications.

Clinical Outcomes of Traditional Chinese Medicine Compound Formula in Treating Sleep-Disordered Breathing Patients

Sleep-Disordered Breathing (SDB) is a prevalent affliction, which can range from simple snoring to severely obstructive sleep apnea. Compared to current treatment options of SDB, traditional Chinese medicine (TCM) provides a noninvasive way to relieve SDB-related symptoms and deaths. The purpose of this retrospective study was to observe the progression of adult SDB patients who had taken compound formula SZ + NUH (concentrated herbal granules) for four weeks. Depending on subjects’ individual needs, minor additions of formulas or single herbs were allowed. We found a significant amount of relief from snoring among the 118 enrolled subjects, according to before-after scores observed through the Snore Outcome Survey (SOS). Furthermore, as projected from the moderate linear correlation in before-after scores, we inferred that those cases with more severe snoring at baseline had greater improvement after treatment. Excessive daytime sleepiness was also significantly improved according to the results of the Epworth Sleepiness Scale (ESS). Assessment, using the SF-36 (Taiwanese version) revealed possible benefits of SZ + NUH in improving multiple facets of subjects’ quality of life. During treatment, no significant side effects occurred. In conclusion, the TCM compound formula based on SZ + NUH could be a safe and effective option for SDB treatment.

Impact of gender on snore-based obstructive sleep apnea screening

Obstructive sleep apnea syndrome (OSA) is a serious widespread disease in which upper airways (UA) are collapsed during sleep. OSA has marked male predominance in prevalence. Although women are less vulnerable to OSA, under-diagnosed OSA in women may associate with serious consequences. Snoring is commonly associated with OSA and one of the earliest symptoms. Snore sounds (SS) are generated due to vibration of the collapsing soft tissues of the UA. Structural and functional properties of the UA are gender dependent. SS capture these time varying gender attributed UA properties and those could be embedded in the acoustic properties of SS. In this paper, we investigate the gender-specific acoustic property differences of SS and try to exploit these differences to enhance the snore-based OSA detection performance. We developed a snore-based multi-feature vector for OSA screening and one time-measured neck circumference was augmented. Snore features were estimated from SS recorded in a sleep laboratory from 35 females and 51 males and multi-layer neural network-based pattern recognition algorithms were used for OSA/non-OSA classification. The results were K-fold cross-validated. Gender-dependent modeling resulted in an increase of around 7% in sensitivity and 6% in specificity at the decision threshold AHI = 15 against a gender-neutral model. These results established the importance of adopting gender-specific models for the snore-based OSA screening technique.

Snoring and obstructive sleep apnea

Obstructive sleep apnea (OSA) may be associated with myriad clinical consequences such as increased risk of systemic hypertension, coronary vascular disease, congestive heart failure, cerebrovascular disease, glucose intolerance, impotence, obesity, pulmonary hypertension, gastroesophageal reflux, and impaired concentration. Nonetheless, OSA remains undiagnosed in 82% of men and 93% of women with the condition. Early identification and treatment of OSA provides significant relief for individuals, prevents complications of OSA, and reduces overall health care costs. Better understanding of the pathogenesis, risk factors, diagnosis, and treatment of OSA has the potential to improve early recognition of OSA and prevention of adverse effects on the individual and society.

Evaluation of the upper airway in children and adolescents with cystic fibrosis and obstructive sleep apnea syndrome

OBJECTIVE

Obstructive sleep apnea syndrome (OSAS) in cystic fibrosis (CF) patients may be associated with the presence of upper airway obstruction caused by chronic infection and nasal polyposis that may also contribute to OSAS severity. Our objective was to identify the profile of findings in CF and OSAS patients by performing upper airway examinations.

METHODOLOGY

Observational, cross-sectional study involving 63 children and adolescents between the ages of 2 and 14 with CF. All patients answered a questionnaire and underwent a standard otolaryngology examination, including an endoscopic nasal and nocturnal polysomnography. OSAS diagnosis was confirmed if the obstructive apnea index was >or=1.

RESULTS

OSAS was identified in 35 (55.6%) patients. The upper airway findings were evaluated using multiple correspondence factorial analysis. The OSAS group presented with overjet >2mm, enlarged pharyngeal pillars, palatine tonsils and pharyngeal tonsils hypertrophy, ogival hard palates and characteristics of chronic rhinosinusitis.

CONCLUSION

Bone and soft tissue structural alterations of the upper airway and chronic rhinosinusitis were associated with the OSAS group patients.