Influence of the device used for obstructive sleep apnea diagnosis on body position: a comparison between polysomnography and portable monitor.

PURPOSE: Different devices have been used for the diagnosis of obstructive sleep apnea (OSA), which differ in the number of sensors used. The numerous sensors used in more complex sleep studies such as in-lab polysomnography may influence body position during sleep. We hypothesized that patients submitted to in-lab polysomnography (PSG) would spend more time in the supine position than patients submitted to an ambulatory Portable Monitor (PM) sleep study. METHODS: Body position during PSG and PM studies was compared among two distinct groups of patients matched for age, body-mass index (BMI), apnea-hypopnea index (AHI), and gender. Predictors of time spent in the supine position were determined using a multiple linear regression model. RESULTS: Of 478 participants who underwent either PSG or PM studies, mean age: 61[43-66] years; males: 43.9%; BMI: 28.4[26.1-31.1]kg/m2; AHI 14[7-27] events/hour). Participants who underwent PSG studies spent more time in the supine position (41[16-68]% than participants who underwent PM studies (34[16-51]%), P = 0.014. Participants with OSA spent more time in the supine position than participants without OSA, both among the PSG and PM groups P < 0.05). Gender, BMI, OSA severity, and sleep study type were independent predictors of time spent in the supine position. CONCLUSION: In-lab PSG may increase time spent in the supine position and overestimate OSA severity compared to a PM sleep study. OSA diagnosis is also associated with increased time spent in the supine position. The potential influence on the sleeping position should be taken into account when choosing among the different sleep study types for OSA diagnosis.

Structure and severity of pharyngeal obstruction determine oral appliance efficacy in sleep apnoea.

KEY POINTS: •Some patients with obstructive sleep apnoea (OSA) respond well to oral appliance therapy, whereas others do not for reasons that are unclear. •In the present study, we used gold-standard measurements to demonstrate that patients with a posteriorly-located tongue (natural sleep endoscopy) exhibit a preferential improvement in collapsibility (lowered critical closing pressure) with oral appliances. •We also show that patients with both posteriorly-located tongue and less severe collapsibility (predicted responder phenotype) exhibit greater improvements in severity of obstructive sleep apnoea (i.e. reduction in event frequency by 83%, in contrast to 48% in predicted non-responders). •The present study suggests that the structure and severity of pharyngeal obstruction determine the phenotype of sleep apnoea patients who benefit maximally from oral appliance efficacy. ABSTRACT: A major limitation to the administration of oral appliance therapy for obstructive sleep apnoea (OSA) is that therapeutic responses remain unpredictable. In the present study, we tested the hypotheses that oral appliance therapy (i) reduces pharyngeal collapsibility preferentially in patients with posteriorly-located tongue and (ii) is most efficacious (reduction in apnoea-hypopnea index; AHI) in patients with a posteriorly-located tongue and less-severe baseline pharyngeal collapsibility. Twenty-five OSA patients underwent upper airway endoscopy during natural sleep to assess tongue position (type I: vallecula entirely visible; type II: vallecula obscured; type III: vallecula and glottis obscured), as well as obstruction as a result of other pharyngeal structures (e.g. epiglottis). Additional sleep studies with and without oral appliance were performed to measure collapsibility (critical closing pressure; Pcrit) and assess treatment efficacy. Overall, oral appliance therapy reduced Pcrit by 3.9 ± 2.4 cmH2 O (mean ± SD) and AHI by 69 ± 19%. Therapy lowered Pcrit by an additional 2.7 ± 0.9 cmH2 O in patients with posteriorly-located tongue (types II and III) compared to those without (type I) (P < 0.008). Posteriorly-located tongue (p = 0.03) and lower collapsibility (p = 0.04) at baseline were significant determinants of (greater-than-average) treatment efficacy. Predicted responders (type II and III and Pcrit < 1 cmH2 O) exhibited a greater reduction in the AHI (83 ± 9 vs. 48 ± 8% baseline, P < 0.001) and a lower treatment AHI (9 ± 6 vs. 32 ± 15 events h-1 , P < 0.001) than predicted non-responders. The site and severity of pharyngeal collapse combine to determine oral appliance efficacy. Specifically, patients with a posteriorly-located tongue plus less-severe collapsibility are the strongest candidates for oral appliance therapy.

Palatal prolapse as a signature of expiratory flow limitation and inspiratory palatal collapse in patients with obstructive sleep apnoea.

In some individuals with obstructive sleep apnoea (OSA), the palate prolapses into the velopharynx during expiration, limiting airflow through the nose or shunting it out of the mouth. We hypothesised that this phenomenon causes expiratory flow limitation (EFL) and is associated with inspiratory "isolated" palatal collapse. We also wanted to provide a robust noninvasive means to identify this mechanism of obstruction.Using natural sleep endoscopy, 1211 breaths from 22 OSA patients were scored as having or not having palatal prolapse. The patient-level site of collapse (tongue-related, isolated palate, pharyngeal lateral walls and epiglottis) was also characterised. EFL was quantified using expiratory resistance at maximal epiglottic pressure. A noninvasive EFL index (EFLI) was developed to detect the presence of palatal prolapse and EFL using the flow signal alone. In addition, the validity of using nasal pressure was assessed.A cut-off value of EFLI >0.8 detected the presence of palatal prolapse and EFL with an accuracy of >95% and 82%, respectively. The proportion of breaths with palatal prolapse predicted isolated inspiratory palatal collapse with 90% accuracy.This study demonstrates that expiratory palatal prolapse can be quantified noninvasively, is associated with EFL and predicts the presence of inspiratory isolated palatal collapse.

Severe obstructive sleep apnea is associated with cochlear function impairment.

PURPOSE: The purpose of this study is to investigate the association between obstructive sleep apnea (OSA) with middle ear acoustic transference and cochlear function. METHODS: Male individuals with and without mild, moderate, and severe OSA according to standard criteria of full polysomnography and no co-morbidities were studied. Subjects with BMI ≥40 kg/m2, present or past treatment for OSA, with heart failure, diabetes, hypertension, dyslipidemia, stroke, use of chronic medications, and previous history of risk for hearing loss were excluded. All subjects were submitted to full polysomnography, evaluation of wideband acoustic immittance by energy of absorbance (EA), and distortion product otoacoustic emissions (DPOAE). RESULTS: We studied 38 subjects (age 35.8 ± 7.2 years, BMI 28.8 ± 3.8 kg/m2) divided into no OSA (n = 10, age 33.6 ± 6.4 years, BMI 26.9 ± 4.1 kg/m2), mild (n = 11, age 32.8 ± 2.9 years, BMI 28.5 ± 3.5 kg/m2), moderate (n = 8, age 34.1 ± 6.8 years, BMI 29.6 ± 3.3 kg/m2), and severe OSA (n = 9, age 41.2 ± 9.2 years, BMI 30.5 ± 3.8 kg/m2). EA was similar between groups. In contrast, patients with severe OSA presented significantly lower DPOAE amplitudes when compared to the control, mild, and moderate OSA groups (p ≤ 0.03, for all comparisons). CONCLUSIONS: Acoustic transference function of middle ear is similar in adults with and without OSA. Severe OSA is independently associated with cochlear function impairment in patients with no significant co-morbidities.

Predicting epiglottic collapse in patients with obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is characterised by pharyngeal obstruction occurring at different sites. Endoscopic studies reveal that epiglottic collapse renders patients at higher risk of failed oral appliance therapy or accentuated collapse on continuous positive airway pressure. Diagnosing epiglottic collapse currently requires invasive studies (imaging and endoscopy). As an alternative, we propose that epiglottic collapse can be detected from the distinct airflow patterns it produces during sleep.23 OSA patients underwent natural sleep endoscopy. 1232 breaths were scored as epiglottic/nonepiglottic collapse. Several flow characteristics were determined from the flow signal (recorded simultaneously with endoscopy) and used to build a predictive model to distinguish epiglottic from nonepiglottic collapse. Additionally, 10 OSA patients were studied to validate the pneumotachograph flow features using nasal pressure signals.Epiglottic collapse was characterised by a rapid fall(s) in the inspiratory flow, more variable inspiratory and expiratory flow and reduced tidal volume. The cross-validated accuracy was 84%. Predictive features obtained from pneumotachograph flow and nasal pressure were strongly correlated.This study demonstrates that epiglottic collapse can be identified from the airflow signal measured during a sleep study. This method may enable clinicians to use clinically collected data to characterise underlying physiology and improve treatment decisions.

Clinical predictors of the respiratory arousal threshold in patients with obstructive sleep apnea.

RATIONALE: A low respiratory arousal threshold (ArTH) is one of several traits involved in obstructive sleep apnea pathogenesis and may be a therapeutic target; however, there is no simple way to identify patients without invasive measurements. OBJECTIVES: To determine the physiologic determinates of the ArTH and develop a clinical tool that can identify patients with low ArTH. METHODS: Anthropometric data were collected in 146 participants who underwent overnight polysomnography with an epiglottic catheter to measure the ArTH (nadir epiglottic pressure before arousal). The ArTH was measured from up to 20 non-REM and REM respiratory events selected randomly. Multiple linear regression was used to determine the independent predictors of the ArTH. Logistic regression was used to develop a clinical scoring system. MEASUREMENTS AND MAIN RESULTS: Nadir oxygen saturation as measured by pulse oximetry, apnea-hypopnea index, and the fraction of events that were hypopneas (Fhypopneas) were independent predictors of the ArTH (r(2) = 0.59; P < 0.001). Using this information, we used receiver operating characteristic analysis and logistic regression to develop a clinical score to predict a low ArTH, which allocated a score of 1 to each criterion that was satisfied: (apnea-hypopnea index, <30 events per hour) + (nadir oxygen saturation as measured by pulse oximetry >82.5%) + (Fhypopneas >58.3%). A score of 2 or above correctly predicted a low arousal threshold in 84.1% of participants with a sensitivity of 80.4% and a specificity of 88.0%, a finding that was confirmed using leave-one-out cross-validation analysis. CONCLUSIONS: Our results demonstrate that individuals with a low ArTH can be identified from standard, clinically available variables. This finding could facilitate larger interventional studies targeting the ArTH.

Critical evaluation of screening questionnaires for obstructive sleep apnea in patients undergoing coronary artery bypass grafting and abdominal surgery.

BACKGROUND: Obstructive sleep apnea (OSA) is an independent risk factor for complications after surgery. However, OSA remains largely under recognized, and questionnaires designed to detect OSA have shown inconsistent results. Patients with cardiovascular diseases may not present with the typical symptoms of OSA. We therefore sought to compare the performance of screening questionnaires of patients referred for coronary artery bypass grafting (CABG) versus abdominal surgery (Abd surgery). METHODS: We studied 40 consecutive patients referred for CABG [29 men; age 56 ± 7 years; body mass index (BMI) 30 ± 4 kg/m(2)], and 41 referred to Abd Surgery matched for age, gender, and BMI (28 men; age 56 ± 8 years; BMI 29 ± 5 kg/m(2)). All patients were evaluated with validated questionnaires to predict OSA (STOP-Bang and Berlin), Epworth sleepiness scale (ESS) and full overnight polysomnography. RESULTS: The prevalence of OSA (apnea-hypopnea index ≥15 events/hour) in the CABG and Abd surgery groups was similar (52 and 41 %, respectively, p = 0.32). The Berlin questionnaire showed similar sensitivity (67 vs. 82 %, p = 0.17) but lower specificity in the CABG group (26 vs. 62 %, p = 0.02). The STOP-BANG questionnaire had a high sensitivity (90 vs. 94 %, p = 0.42) but low specificity (5 vs. 13 %, p = 0.25) in the CABG and Abd surgery groups, respectively. Patients referred for CABG slept less (323 [285-376] vs. 378 [308-415] minutes, p = 0.04) but had lower levels of daytime sleepiness than Abd surgery patients had (ESS, 6 ± 4 vs. 9 ± 5; p = 0.01, respectively). CONCLUSIONS: Presenting clinical characteristics of OSA are modulated by the population evaluated and may affect the performance of screening questionnaires.

Effects of hyperoxia and hypoxia on the physiological traits responsible for obstructive sleep apnoea.

Oxygen therapy is known to reduce loop gain (LG) in patients with obstructive sleep apnoea (OSA), yet its effects on the other traits responsible for OSA remain unknown. Therefore, we assessed how hyperoxia and hypoxia alter four physiological traits in OSA patients. Eleven OSA subjects underwent a night of polysomnography during which the physiological traits were measured using multiple 3-min 'drops' from therapeutic continuous positive airway pressure (CPAP) levels. LG was defined as the ratio of the ventilatory overshoot to the preceding reduction in ventilation. Pharyngeal collapsibility was quantified as the ventilation at CPAP of 0 cmH2O. Upper airway responsiveness was defined as the ratio of the increase in ventilation to the increase in ventilatory drive across the drop. Arousal threshold was estimated as the level of ventilatory drive associated with arousal. On separate nights, subjects were submitted to hyperoxia (n = 9; FiO2 ∼0.5) or hypoxia (n = 10; FiO2 ∼0.15) and the four traits were reassessed. Hyperoxia lowered LG from a median of 3.4 [interquartile range (IQR): 2.6-4.1] to 2.1 (IQR: 1.3-2.5) (P < 0.01), but did not alter the remaining traits. By contrast, hypoxia increased LG [median: 3.3 (IQR: 2.3-4.0) vs. 6.4 (IQR: 4.5-9.7); P < 0.005]. Hypoxia additionally increased the arousal threshold (mean ± s.d. 10.9 ± 2.1 l min(-1) vs. 13.3 ± 4.3 l min(-1); P < 0.05) and improved pharyngeal collapsibility (mean ± s.d. 3.4 ± 1.4 l min(-1) vs. 4.9 ± 1.3 l min(-1); P < 0.05), but did not alter upper airway responsiveness (P = 0.7). This study demonstrates that the beneficial effect of hyperoxia on the severity of OSA is primarily based on its ability to reduce LG. The effects of hypoxia described above may explain the disappearance of OSA and the emergence of central sleep apnoea in conditions such as high altitude.

Obstructive Sleep Apnea Is a Distinct Physiological Endotype in Individuals with Comorbid Insomnia and Sleep Apnea.

Rationale: With up to 40% of individuals with either insomnia or obstructive sleep apnea (OSA) demonstrating clinically significant symptoms of the other disorder, the high degree of comorbidity among the two most common sleep disorders suggests a bidirectional relationship and/or shared underpinnings. Although the presence of insomnia disorder is believed to influence the underlying pathophysiology of OSA, this influence is yet to be examined directly. Objectives: To investigate whether the four OSA endotypes (upper airway collapsibility, muscle compensation, loop gain, and the arousal threshold) are different in patients with OSA with and without comorbid insomnia disorder. Methods: Using the ventilatory flow pattern captured from routine polysomnography, the four OSA endotypes were measured in 34 patients with OSA who met the diagnostic criteria for insomnia disorder (COMISA) and 34 patients with OSA without insomnia (OSA only). Patients demonstrated mild-to-severe OSA (apnea-hypopnea index, 25.8 ± 2.0 events/h) and were individually matched according to age (50.2 ± 1.5 yr), sex (42 male: 26 female), and body mass index (29.3 ± 0.6 kg/m2). Results: Compared with patients with OSA without comorbid insomnia, patients with COMISA demonstrated significantly lower respiratory arousal thresholds (128.9 [118.1 to 137.1] vs. 147.7 [132.3 to 165.0] % eupneic ventilation ([Formula: see text]); U = 261; 95% confidence interval [CI], -38.3 to -13.9; d = 1.1; P < 0.001), less collapsible upper airways (88.2 [85.5 to 94.6] vs. 72.9 [64.7 to 79.2] %[Formula: see text]; U = 1081; 95% CI, 14.0 to 26.7; d = 2.3; P < 0.001), and more stable ventilatory control (i.e., lower loop gain: 0.51 [0.44 to 0.56] vs. 0.58 [0.49 to 0.70]; U = 402; 95% CI, -0.2 to -0.01; d = 0.05; P = 0.03). Muscle compensation was similar between groups. Moderated linear regression revealed that the arousal threshold moderated the relationship between collapsibility and OSA severity in patients with COMISA but not in patients with OSA only. Conclusions: A low arousal threshold is an overrepresented endotypic trait in individuals with COMISA and may exhibit a greater relative contribution to OSA pathogenesis in these patients. Contrastingly, the prevalence of a highly collapsible upper airway in COMISA was low, suggesting that anatomical predisposition may contribute less to OSA development in COMISA. Based on our findings, we theorize that conditioned hyperarousal perpetuating insomnia may translate to a reduced arousal threshold to respiratory events, thereby increasing the risk or severity of OSA. Therapies that target increased nocturnal hyperarousal (e.g., through cognitive behavior therapy for insomnia) may be effective in individuals with COMISA. Clinical trial registered with the Australian and New Zealand Clinical Trial Registry (ACTRN12616000586415).

Respiratory arousal threshold among patients with isolated sleep apnea and with comorbid insomnia (COMISA).

Insomnia and obstructive sleep apnea (OSA) are common sleep disorders and frequently coexist (COMISA). Arousals from sleep may be a common link explaining the frequent comorbidity of both disorders. Respiratory arousal threshold (AT) is a physiologic measurement of the level of respiratory effort to trigger an arousal from sleep. The impact of COMISA on AT is not known. We hypothesized that a low AT is more common among COMISA than among patients with OSA without insomnia. Participants referred for OSA diagnosis underwent a type 3 sleep study and answered the insomnia severity index (ISI) questionnaire and the Epworth sleepiness scale. Participants with an ISI score ≥ 15 were defined as having insomnia. Sleep apnea was defined as an apnea hypopnea index (AHI) ≥ 15 events/h. Low AT was determined using a previously validated score based on 3 polysomnography variables (AHI, nadir SpO2 and the frequency of hypopneas). OSA-only (n = 51) and COMISA (n = 52) participants had similar age (61[52-68] vs 60[53-65] years), body-mass index (31.3[27.7-36.2] vs 32.2[29.5-38.3] kg/m2) and OSA severity (40.2[27.5-60] vs 37.55[27.9-65.2] events/h): all p = NS. OSA-only group had significantly more males than the COMISA group (58% vs 33%, p = 0.013. The proportion of participants with a low AT among OSA-only and COMISA groups was similar (29 vs 33%, p = NS). The similar proportion of low AT among COMISA and patients with OSA suggests that the respiratory arousal threshold may not be related to the increased arousability of insomnia.

Clinical Decision-making for Continuous Positive Airway Pressure Mask Selection.

Continuous positive airway pressure is the gold standard treatment for obstructive sleep apnea. Different interfaces with distinct characteristics, advantages, and disadvantages are available, which may influence long-term adherence. Oronasal masks have been increasingly used. However, recent evidence suggest that nasal masks are more effective when continuous positive airway pressure is used to treat obstructive sleep apnea. The main objective of this review is to describe the basis for the selection of the interface for the treatment of obstructive sleep apnea with continuous positive airway pressure.

Insomnia episodes, new-onset pharmacological treatments, and other sleep disturbances during the COVID-19 pandemic: a nationwide cross-sectional study in Brazilian health care professionals.

STUDY OBJECTIVES: To evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on insomnia and other sleep disturbances in health care professionals. METHODS: A survey was distributed using social media and organizational emails to Brazilian active health care professionals during the COVID-19 outbreak. We explored potential associated factors including age, sex, occupation, workplace, work hours, income, previous infection with COVID-19, recent/current contact with COVID-19 patients, regional number of incident deaths, anxiety, and burnout. We evaluated new-onset/previous insomnia worsening episodes (primary outcome), new pharmacological treatments, sleep quality, duration, nightmares, and snoring (secondary outcomes). RESULTS: A total of 4,384 health professionals from all regions of the country were included in the analysis (44 ± 12 years, 76% females, 53.8% physicians). Overall, 55.7% were assisting patients with COVID-19, and 9.2% had a previous COVID-19 infection. The primary outcome occurred in 32.9% of respondents in parallel to 13% new pharmacological treatments for insomnia. The sleep quality worsened for 61.4%, while 43.5% and 22.8% reported ≥ 1-hour sleep duration reduction and worsening or new-onset nightmares, respectively. Multivariate analyses showed that age (odds ratio [OR]: 1.008; 95% confidence interval [CI] 1.001-1.015), females (OR: 1.590; 95% CI 1.335-1.900), weight change (decrease: OR: 1.772; 95% CI 1.453-2.161; increase: OR: 1.468; 95% CI 1.249-1.728), prevalent anxiety (OR: 3.414; 95% CI 2.954-3.948), new-onset burnout (OR: 1.761; 95% CI 1.489-2.083), family income reduction > 30% (OR: 1.288; 95% CI 1.069-1.553), and assisting patients with COVID-19 (OR: 1.275; 95% CI 1.081-1.506) were independently associated with new-onset or worsening of previous insomnia episodes. CONCLUSIONS: We observed a huge burden of insomnia episodes and other sleep disturbances in health care professionals during the COVID-19 pandemic. CITATION: Drager LF, Pachito DV, Moreno CRC, et al. Insomnia episodes, new-onset pharmacological treatments, and other sleep disturbances during the COVID-19 pandemic: a nationwide cross-sectional study in Brazilian health care professionals. J Clin Sleep Med. 2022;18(2):373-382.

Sleep quality and quality of life in patients with hypertrophic cardiomyopathy.

OBJECTIVES: To evaluate clinical predictors of poor sleep quality and quality of life (QOL) in patients with hypertrophic cardiomyopathy (HCM). METHODS: Consecutive stable patients with HCM were evaluated for the risk of obstructive sleep apnea (OSA) by the Berlin Questionnaire, daytime sleepiness by the Epworth Sleepiness Scale, sleep quality by the Pittsburgh Sleep Questionnaire Index and QOL by the Minnesota Living with Heart Failure Questionnaire. Asymptomatic subjects without HCM were used as controls. RESULTS: We studied 84 patients with HCM and 42 controls who were similar with regard to gender (49 vs. 50% males), age [52 (38-62) vs. 47 (33-58) years] and body mass index (27 ± 4 vs. 27 ± 5). HCM diagnosis, high risk for OSA and female gender were independently associated with poor sleep quality in the entire population. Among patients with HCM, poor QOL was independently associated with poor sleep quality, New York Heart Association functional class and diuretic therapy. CONCLUSION: Poor sleep quality is very common in patients with HCM and may have a negative impact on the QOL, which in turn is an important marker of prognosis in patients with cardiomyopathies.

Effects of oropharyngeal exercises on patients with moderate obstructive sleep apnea syndrome.

RATIONALE: Upper airway muscle function plays a major role in maintenance of the upper airway patency and contributes to the genesis of obstructive sleep apnea syndrome (OSAS). Preliminary results suggested that oropharyngeal exercises derived from speech therapy may be an effective treatment option for patients with moderate OSAS. OBJECTIVES: To determine the impact of oropharyngeal exercises in patients with moderate OSAS. METHODS: Thirty-one patients with moderate OSAS were randomized to 3 months of daily ( approximately 30 min) sham therapy (n = 15, control) or a set of oropharyngeal exercises (n = 16), consisting of exercises involving the tongue, soft palate, and lateral pharyngeal wall. MEASUREMENTS AND MAIN RESULTS: Anthropometric measurements, snoring frequency (range 0-4), intensity (1-3), Epworth daytime sleepiness (0-24) and Pittsburgh sleep quality (0-21) questionnaires, and full polysomnography were performed at baseline and at study conclusion. Body mass index and abdominal circumference of the entire group were 30.3 +/- 3.4 kg/m(2) and 101.4 +/- 9.0 cm, respectively, and did not change significantly over the study period. No significant change occurred in the control group in all variables. In contrast, patients randomized to oropharyngeal exercises had a significant decrease (P < 0.05) in neck circumference (39.6 +/- 3.6 vs. 38.5 +/- 4.0 cm), snoring frequency (4 [4-4] vs. 3 [1.5-3.5]), snoring intensity (3 [3-4] vs. 1 [1-2]), daytime sleepiness (14 +/- 5 vs. 8 +/- 6), sleep quality score (10.2 +/- 3.7 vs. 6.9 +/- 2.5), and OSAS severity (apnea-hypopnea index, 22.4 +/- 4.8 vs. 13.7 +/- 8.5 events/h). Changes in neck circumference correlated inversely with changes in apnea-hypopnea index (r = 0.59; P < 0.001). CONCLUSIONS: Oropharyngeal exercises significantly reduce OSAS severity and symptoms and represent a promising treatment for moderate OSAS. Clinical trial registered with www.clinicaltrials.gov (NCT 00660777).

Discriminating the severity of pharyngeal collapsibility in men using anthropometric and polysomnographic indices.

STUDY OBJECTIVES: Although obstructive sleep apnea results from the combination of different pathophysiologic mechanisms, the degree of anatomical compromise remains the main responsible factor. The passive pharyngeal critical closing pressure (Pcrit) is a technique used to assess the collapsibility of the upper airway and is often used as a surrogate measure of this anatomical compromise. Patients with a low Pcrit (ie, less collapsible airway) are potential candidates for non-continuous positive airway pressure therapies. However, Pcrit determination is a technically complex method not available in clinical practice. We hypothesized that the discrimination between low and high Pcrit can be estimated from simple anthropometric and polysomnographic indices. METHODS: Men with and without obstructive sleep apnea underwent Pcrit determination and full polysomnography. Receiver operating characteristics analysis was performed to select the best cutoff of each variable to predict a high Pcrit (Pcrit ≥ 2.5 cmH2O). Multiple logistic regression analysis was performed to create a clinical score to predict a high Pcrit. RESULTS: We studied 81 men, 48 ± 13 years of age, with an apnea-hypopnea index of 32 [14-60], range 1-96 events/h), and Pcrit of -0.7 ± 3.1 (range, -9.1 to +7.2 cmH2O). A high and low Pcrit could be accurately identified by polysomnographic and anthropometric indices. A score to discriminate Pcrit showed good performance (area under the curve = 0.96; 95% confidence interval, 0.91-1.00) and included waist circumference, non-rapid eye movement obstructive apnea index/apnea-hypopnea index, mean obstructive apnea duration, and rapid eye movement apnea-hypopnea index. CONCLUSIONS: A low Pcrit (less collapsible) can be estimated from a simple clinical score. This approach may identify candidates more likely to respond to non-continuous positive airway pressure therapies for obstructive sleep apnea.

The Importance of Mask Selection on Continuous Positive Airway Pressure Outcomes for Obstructive Sleep Apnea. An Official American Thoracic Society Workshop Report.

Continuous positive airway pressure (CPAP) remains the major treatment option for obstructive sleep apnea (OSA). The American Thoracic Society organized a workshop to discuss the importance of mask selection for OSA treatment with CPAP. In this workshop report, we summarize available evidence about the breathing route during nasal and oronasal CPAP and the importance of nasal symptoms for CPAP outcomes. We explore the mechanisms of air leaks during CPAP treatment and possible alternatives for leak control. The impact of nasal and oronasal CPAP on adherence, residual apnea-hypopnea index, unintentional leaks, and pressure requirements are also compared. Finally, recommendations for patient and partner involvement in mask selection are presented, and future directions to promote personalized mask selection are discussed.