Optimal Continuous Positive Airway Pressure Research Articles

Association Between Obstructive Sleep Apnea (OSA) Severity and Optimal Continuous Positive Airway Pressure (CPAP); Do Severe OSA Patients Always Need High CPAP Pressure?

Objective: Obstructive sleep apnea (OSA) is a prevalent sleep disorder associated with an increased risk of cardiovascular disease. Severity of OSA is assessed using the apnea-hypopnea index (AHI), but the optimal continuous positive airway pressure (CPAP) does not always correlate proportionally with AHI. This study aims to identify factors leading to the need for high CPAP pressure despite low AHI or vice versa.Methods: The study includes 91 patients diagnosed with OSA through polysomnography. Participants undergoing CPAP titration were categorized in three groups based on AHI (30/h) and optimal CPAP pressure (10 cm H<sub>2</sub>O); low AHI and high CPAP pressure group (LH group), high AHI and low CPAP pressure group (HL group), direct proportion group (DP group). The Kruskal–Wallis nonparametric statistical test is used to identify significant differences between the three groups.Results: Among the subjects, 78% were male, with no significant age or BMI differences between groups. There were 36 (39.6%) subjects with mild to moderate OSA and 55 (60.4%) subjects with severe OSA. The study revealed that patients requiring high CPAP pressure despite low AHI (LH group) had lower AHI, oxygen desaturation index, and various other parameters compared to other groups as expected. However, certain factors like the percentage of hypopnea in AHI, limb movement (LM) arousal index, and spontaneous arousal index were higher in the LH group.Conclusion: Patients with mild to moderate OSA requiring high CPAP pressure are more likely associated with specific aspects such as hypopnea in AHI, LM arousal, and spontaneous arousal index, presenting unpredictable outcomes.

Continuous positive airway pressure and adherence in patients with different endotypes of obstructive sleep apnea.

Determining the endotypes of obstructive sleep apnea (OSA) has potential implications for precision interventions. Here we assessed whether continuous positive airway pressure (CPAP) treatment outcomes differ across endotypic subgroups. We conducted a retrospective analysis of data obtained from 225 patients with moderate-to-severe OSA from a single sleep centre. Polysomnographic and CPAP titration study data were collected between May 2020 and January 2022. One-month CPAP treatment adherence was followed. Obstructive sleep apnea endotypes, namely arousal threshold, collapsibility, loop gain, and upper airway gain were estimated from polysomnography and dichotomised as high versus low. We examined associations between endotypic subgroups and (1) optimal CPAP titration pressure, (2) CPAP-related improvements in sleep architecture (proportions of slow-wave and rapid eye movement (REM) sleep), and (3) CPAP adherence. We observed that patients with high collapsibility required a higher CPAP pressure than those with low collapsibility (∆ = 0.4 cmH2 O, 95% confidence interval [CI] = 0.3-1.7). A larger increase in slow-wave sleep and in REM sleep proportions after CPAP treatment were observed in patients with a high arousal threshold, high collapsibility, high loop gain, or high upper airway gain than in those with low levels of endotypes. High loop gain and high collapsibility were independently associated with longer CPAP use hours per night (∆ = 0.6 h, 95% CI = 0.2-1.5 and ∆ = 0.3 h, 95% CI = 0.03-1.5, respectively). In conclusion, different endotypic subgroups of OSA exhibit a difference in outcomes of CPAP treatment. Knowledge of endotypes may help clinicians to understand which patients are expected to benefit most from CPAP therapy prior to its administration.

Conversion of Atrial Fibrillation to Normal Sinus Rhythm With Optimal Continuous Positive Airway Pressure Therapy in Severe Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) and atrial fibrillation (AF) are associated with increased morbidity and mortality. OSA and AF share multiple risk factors, including hypertension, cardiovascular disorders, congestive heart failure, and metabolic syndrome. Although the two conditions are likely to have a bidirectional association, recent studies have suggested that OSA contributes to the development of AF through direct mechanical effects on cardiac remodeling. We report a patient with severe OSA showing immediate conversion of AF to normal sinus rhythm with optimal continuous positive airway pressure (CPAP) therapy. This supports that OSA may lead to AF, which can be effectively reversed with CPAP therapy.

Clinical and polysomnographic predictors of suboptimal auto-adjusting CPAP titration in adult OSA patients: a single-center study.

To examine potential clinical, demographic, anthropometric, and polysomnographic predictors of successful auto-adjusting continuous positive airway pressure (CPAP) titration for treatment of obstructive sleep apnea (OSA). This cross-sectional study was conducted in adults diagnosed with moderate-to-severe OSA (baseline apnea-hypopnea index [AHI] ≥ 15.0/h), who underwent auto-adjusting CPAP titration (S9 or S10 AutoSet ResMed®) in a sleep laboratory setting while wearing a nasal or pillow mask. Participants were then grouped into two groups: optimal CPAP titration (residual AHI < 5.0/h) or suboptimal CPAP titration (residual AHI ≥ 5.0/h). Multivariate logistic regression analysis was used to assess possible independent predictive factors for suboptimal CPAP titration. A total of 1222 adults consisting of 874 subjects with optimal CPAP titration (71.5%) and 348 subjects with suboptimal CPAP titration (28.5%) were evaluated. Multivariate analysis resulted in a model with an adequate calibration (Hosmer-Lemeshow chi-square-test: 7.088; p = 0.527), with male sex, higher values of baseline AHI, therapeutic pressure (95th percentile), and mask leak (95th percentile) emerging as significant and independent predictors for suboptimal CPAP titration: adjusted odds ratio (OR): 1.456 (95% confidence interval [CI] 1.076-1.971; p = 0.015), OR: 1.009 (95% CI 1.002-1.016; p = 0.013), OR: 1.281 (95% CI 1.206-1.361; p < 0.001), and 1.035 (1.026-1.043; p < 0.001), respectively. In a large cohort of adults undergoing auto-adjusting CPAP titration due to moderate-to-severe OSA, male sex, increased values of baseline AHI, pressure requirements, and mask leak were significant predictors for less than optimal CPAP titration.

A predictive model for optimal continuous positive airway pressure in the treatment of pure moderate to severe obstructive sleep apnea in China

BackgroundNumerous predictive formulas based on different ethnics have been developed to determine continuous positive airway pressure (CPAP) for patients with obstructive sleep apnea (OSA) without laboratory-based manual titrations. However, few studies have focused on patients with OSA in China. Therefore, this study aimed to develop a predictive equation for determining the optimal value of CPAP for patients with OSA in China.Methods526 pure moderate to severe OSA patients with attended CPAP titrations during overnight polysomnogram were spited into either formula derivation (419 patients) or validation (107 patients) group according to the treatment time. Predictive model was created in the derivation group, and the accuracy of the model was tested in the validation group.ResultsApnea hypopnea index (AHI), body mass index (BMI), longest apnea time (LAT), and minimum percutaneous oxygen saturation (minSpO2) were considered as independent predictors of optimal CPAP through correlation analysis and multiple stepwise regression analysis. The best equation to predict the optimal value of CPAP was: CPAPpred = 7.581 + 0.020*AHI + 0.101*BMI + 0.015*LAT-0.028*minSpO2 (R2 = 27.2%, p < 0.05).The correlation between predictive CPAP and laboratory-determined manual optimal CPAP was significant in the validation group (r = 0.706, p = 0.000). And the pressure determined by the predictive formula did not significantly differ from the manually titrated pressure in the validation cohort (10 ± 1 cmH2O vs. 11 ± 3 cmH2O, p = 0.766).ConclusionsThe predictive formula based on AHI, BMI, LAT, and minSpO2 is useful in calculating the effective CPAP for patients with pure moderate to severe OSA in China to some extent.

Surgical correction of nasal obstruction in obstructive sleep apnea improves CPAP outcomes and compliance.

Although continuous positive airway pressure (CPAP) therapy curtails most of the negative impacts of obstructive sleep apnea (OSA), its efficacy is limited by its low long-term adherence. Nasal obstruction contributes to OSA pathophysiology and necessitates high CPAP titration pressures which reduce CPAP compliance. This study aims at elucidating the outcomes of surgical correction of nasal obstruction in patients intolerant to CPAP therapy. Forty-nine patients with severe OSA intolerant to CPAP secondary to surgically correctable nasal obstruction were operated upon. Patients were evaluated preoperatively and at least 3months after the surgical intervention. Subjective assessment entailed the Nasal Obstruction Symptom Evaluation score (NOSE) and the Epworth Sleepiness Scale (ESS). Objectively the patients were assessed by acoustic rhinometry and standard polysomnography. Nasal surgical intervention resulted in an a statistically significant decrease in the mean NOSE score, ESS and optimal CPAP titration pressure. In addition, theminimalcross-sectional area (MCA1&2) increased significantly postoperatively. There was a positive correlation between the improvement in NOSE score as well as the MCA1& 2 and the postoperative decrease in CPAP titration pressure. Surgical correction of nasal obstruction improved CPAP outcomes and compliance in all patients. Nasal surgery in OSA objectively assessed by acoustic rhinometry improved nasal obstruction with a resultant decrease in the CPAP pressure requirements. Given that lower CPAP pressures improve adherence to CPAP therapy, surgical alleviation of nasal obstruction should be considered a crucial intervention in the management armamentarium of OSA.

New Predictive Equation for Optimal Continuous Positive Airway Pressure in Adult Patients with Obstructive Sleep Apnea

Objective: This study aimed to develop and validate a new continuous positive airway pressure (CPAP) prediction equation and compare it with other formulas.Material and Methods: We retrospectively included patients with obstructive sleep apnea who underwent a CPAP titration study between January 2012 and December 2016. All clinical and polysomnographic data were collected. The new prediction equation was developed using the first data set, and the predictability performance was validated using the second data set.Results: Among the 266 enrolled patients, 73.7% were male, and the mean body mass index (BMI) was 30.8±7.4 kg/m2 . Five variables, namely age, BMI, neck circumference (NC), apnea–hypopnea index (AHI), and minimum pulse oxygen saturation (Min SpO2 ), highly correlated with the optimal titration pressure, and were therefore included in the equation, as stated below:Predicted pressure (cm H2 O) = 2.26 + (0.02xAge) + (0.04xBMI) + (0.11xNC) + (0.04xAHI) - (0.04xMin SpO2 )This equation accounted for 54.4% of the variance in predicting the optimal titration pressure (R2 =0.544, p-value &lt;0.001). Its optimal estimation was 62.0% in the validated group. The equation-derived predicted pressure correlated with good agreement with the laboratory-derived optimal titration pressure (r=0.70, 95% CI=0.6335–0.755, p-value&lt;0.001) according to Bland–Altman analysis. Conclusion: Our equation is highly consistent with the CPAP titration study in predicting fixed CPAP pressure, and is thereby beneficial for sleep technicians in establishing a starting pressure for such studies at a sleep laboratory.

Prediction of optimal continuous positive airway pressure in Thai patients with obstructive sleep apnea

Continuous positive airway pressure (CPAP) is simple and effective treatment for obstructive sleep apnea (OSA) patients. However, the CPAP prediction equation in each country is different. This study aimed to predict CPAP in Thai patients with OSA. A retrospective study was conducted in Thai patients, who OSA was confirmed by polysomnography and CPAP titration from January 2015 to December 2018. Demographics, body mass index (BMI), neck circumference (NC), Epworth sleepiness scale, apnea–hypopnea index (AHI), respiratory disturbance index (RDI), mean and lowest pulse oxygen saturation (SpO2), and optimal pressure were recorded. A total of 180 subjects were included: 72.8% men, age 48.7 ± 12.7 years, BMI 31.0 ± 6.3 kg/m2, NC 40.7 ± 4.1 cm, AHI 42.5 ± 33.0 per hour, RDI 47.1 ± 32.8 per hour, and lowest SpO2 77.1 ± 11.0%. Multiple linear regression analysis identified NC, BMI, RDI, and lowest SpO2. A final CPAP predictive equation was: optimal CPAP (cmH2O) = 4.614 + (0.173 × NC) + (0.067 × BMI) + (0.030 × RDI) − (0.076 × lowest SpO2). This model accounted for 50.0% of the variance in the optimal pressure (R2 = 0.50). In conclusion, a CPAP prediction equation can be used to explain a moderate proportion of the titrated CPAP in Thai patients with OSA. However, the CPAP predictive equation in each country may be different due to differences of ethnicity and physiology.Trial registration: TCTR20200108003.

430 Outcome of Sleep-Wake Pattern in Obstructive Sleep Apnea Patients after Positive Airway Pressure Therapy using Actigraphy

Abstract Introduction The initial phase of continuous positive airway pressure (CPAP) therapy in patients with obstructive sleep apnea (OSA) may affect sleep parameters and PAP compliance. Actigraphy is a validated method using accelerometer to objectively measure sleep parameters in patients with a range of sleep disorders, including OSA, particularly to follow-up after treatment. We compare sleep parameters from actigraphy, sleep log, sleep diary, Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), heart rate and blood pressure in OSA patients before and after CPAP therapy for 1 week. Methods This pilot study have been prospectively performed at Central Chest Institute of Thailand (CCIT) since June to November 2020. Adult OSA patients, diagnosed by ICSD-3 criteria and achieved optimal or good CPAP pressure titration from split-night polysomnography (PSG), were informed and consent to wear actigraphy before and after CPAP therapy each for 1 week. Clinical and sleep parameters were recorded and analyzed using Wilcoxon matched-pair signed-rank and Mann Whitney U test. P-value &amp;lt; 0.05 was considered to have statistical significance. Results All 11 OSA patients participated in this study. Most patients were male (63.6%), hypertension (54.5%) and dyslipidemia (45.4%). Means of age, body mass index (BMI), ESS, PSQI, apnea hypopnea index (AHI), nadir SpO2, and CPAP usage were 45.5 ± 15.9 years, 29.1 ± 5.2 kg/m2, 10.8 ± 3.9, 7.7 ± 2.9, 65.2 ± 37.7 events/h, 82.3 ± 10.8 % and 9.5 ± 3.1 cmH2O, respectively. Comparing before and after 1-week CPAP therapy, an average number of wake bouts ((NWB), 48.4 vs 38 events, p=0.010), ESS (11 vs 9, p=0.035) and PSQI (8 vs 4, p=0.005) were significantly decrease. Additionally, when comparing between poor and good CPAP compliance group, NWB (55.1 vs 36.3 events, p=0.036) and the difference of wake after sleep onset (WASO, 10.5 vs -0.11 min, p=0.035) were significantly decrease. Conclusion OSA patients treated with CPAP for 1-week experienced marked improvement in sleepiness, sleep quality and nighttime awakening. Support (if any):

Are there sex-related differences in therapeutic CPAP levels in adults undergoing in-laboratory titration?

The first-choice therapy for adults with moderate/severe obstructive sleep apnea is continuous positive airway pressure (CPAP). However, studies evaluating whether the therapeutic CPAP level obtained from a titration is affected by sex are surprisingly scarce. Our main objective was to verify if sex influenced the optimal CPAP measurement obtained during a titration. This cross-sectional study was conducted in adults diagnosed with moderate/severe obstructive sleep apnea [baseline apnea-hypopnea index (AHI) ≥ 15.0 events/h] who underwent auto-adjusting CPAP titration (S9 or S10 AutoSet ResMed) in a sleep laboratory setting. All participants used a nasal mask during the titration. The optimal pressure, leak, and residual AHI values were registered. Multiple linear regression was used to evaluate if clinical and polysomnographic data influenced the therapeutic CPAP level setting (95th percentile pressure). A total of 1,006 adults were enrolled: 354 women and 652 men. There were no statistically significant sex-related differences in the CPAP requirements and leak values delineated during the titration; all P-values > .005. However, the median residual AHI was significantly higher in males vs females: 2.7 events/h vs 2.2 events/h (P = .008). Body mass index (β: 0.292, P < .001), baseline AHI (β: 0.167, P < .001), and age (β: 0.065, P = .035) were independent predictors of the therapeutic CPAP level settings. Sex does not significantly influence the therapeutic CPAP settings. However, age, BMI, and baseline AHI emerge as independent predictors of the 95thpercentile CPAP requirement during an auto-adjusting CPAP titration. Duarte RLM, Magalhães-da-Silveira FJ, Gozal D. Are there sex-related differences in therapeutic CPAP levels in adults undergoing in-laboratory titration? JClin Sleep Med. 2021;17(9):1815-1820.

Continuous positive airway pressure improves work of breathing in pediatric chronic heart failure

BackgroundSleep disordered breathing (SDB) is common in adults with chronic heart failure (CHF), but its prevalence in children remains unclear. Continuous positive airway pressure (CPAP) is the treatment of SDB but deleterious hemodynamic effects have been reported. MethodsWe prospectively analyzed SDB in children with CHF and the effect of CPAP on work of breathing (WOB) and cardiac index (CI). Children aged 6 months to 18 years old with CHF due to: 1) dilated cardiomyopathy (DM) with an ejection fraction < 45%, 2) functional single ventricle (SV) or 3) aortic or mitral valve disease awaiting surgery (VD) were eligible for the study. A polysomnography (PSG), measurement of WOB and CI during spontaneous breathing (SB) and CPAP (6, 8 and 10 cmH2O) were performed. ResultsThirty patients with mean age of 6.4 ± 5 years were included (16 DM 16, 10 SV, 4 LV). Twenty (73%) patients had a normal sleep efficiency. Median apnoeas hypopnea index (IAH) was within normal range at 1.6 events/h (0, 14) events/hour. Only one patient had central sleep apnoeas, none had Cheyne-Stokes respiration, and 3 patients had an obstructive AHI between 5 and 10 events/hour. Optimal CPAP level decreased WOB (p = 0.05) and respiratory rate (p = 0.01). ConclusionsSevere SDB was uncommon in children with CHF. However, CPAP may be beneficial by decreasing WOB and respiratory rate without deleterious effects on CI.

Altered K-complex morphology during sustained inspiratory airflow limitation is associated with next-day lapses in vigilance in obstructive sleep apnea.

Determine if changes in K-complexes associated with sustained inspiratory airflow limitation (SIFL) during N2 sleep are associated with next-day vigilance and objective sleepiness. Data from thirty subjects with moderate-to-severe obstructive sleep apnea who completed three in-lab polysomnograms: diagnostic, on therapeutic continuous positive airway pressure (CPAP), and on suboptimal CPAP (4 cmH2O below optimal titrated CPAP level) were analyzed. Four 20-min psychomotor vigilance tests (PVT) were performed after each PSG, every 2 h. Changes in the proportion of spontaneous K-complexes and spectral characteristics surrounding K-complexes were evaluated for K-complexes associated with both delta (∆SWAK), alpha (∆αK) frequencies. Suboptimal CPAP induced SIFL (14.7 (20.9) vs 2.9 (9.2); %total sleep time, p < 0.001) with a small increase in apnea-hypopnea index (AHI3A: 6.5 (7.7) vs 1.9 (2.3); p < 0.01) versus optimal CPAP. K-complex density (num./min of stage N2) was higher on suboptimal CPAP (0.97 ± 0.7 vs 0.65±0.5, #/min, mean ± SD, p < 0.01) above and beyond the effect of age, sex, AHI3A, and duration of SIFL. A decrease in ∆SWAK with suboptimal CPAP was associated with increased PVT lapses and explained 17% of additional variance in PVT lapses. Within-night during suboptimal CPAP K-complexes appeared to alternate between promoting sleep and as arousal surrogates. Electroencephalographic changes were not associated with objective sleepiness. Sustained inspiratory airflow limitation is associated with altered K-complex morphology including the increased occurrence of K-complexes with bursts of alpha as arousal surrogates. These findings suggest that sustained inspiratory flow limitation may be associated with nonvisible sleep fragmentation and contribute to increased lapses in vigilance.

Optimal Continuous Positive Airway Pressure Treatment of Obstructive Sleep Apnea Reduces Daytime Resting Heart Rate in Prediabetes: A Randomized Controlled Study.

BackgroundIt has been widely recognized that obstructive sleep apnea (OSA) is linked to cardiovascular disease. Yet, randomized controlled studies failed to demonstrate a clear cardiovascular benefit from OSA treatment, mainly because of poor adherence to continuous positive airway pressure (CPAP). To date, no prior study has assessed the effect of CPAP treatment on daytime resting heart rate, a strong predictor of adverse cardiovascular outcomes and mortality.Methods and ResultsWe conducted a randomized controlled study in 39 participants with OSA and prediabetes, who received either in‐laboratory all‐night (ie, optimal) CPAP or an oral placebo for 2 weeks. During daytime, participants continued daily activities outside the laboratory. Resting heart rate was continuously assessed over 19 consecutive days and nights using an ambulatory device consisting of a single‐lead ECG and triaxis accelerometer. Compared with placebo, CPAP reduced daytime resting heart rate (treatment difference, −4.1 beats/min; 95% CI, −6.5 to −1.7 beats/min; P=0.002). The magnitude of reduction in daytime resting heart rate after treatment significantly correlated with the magnitude of decrease in plasma norepinephrine, a marker of sympathetic activity (r=0.44; P=0.02), and the magnitude of decrease in OSA severity (ie, apnea‐hypopnea index [r=0.48; P=0.005], oxygen desaturation index [r=0.50; P=0.003], and microarousal index [r=0.57; P<0.001]).ConclusionsThis proof‐of‐concept randomized controlled study demonstrates, for the first time, that CPAP treatment, when optimally used at night, reduces resting heart rate during the day, and therefore has positive cardiovascular carry over effects. These findings suggest that better identification and treatment of OSA may have important clinical implications for cardiovascular disease prevention.RegistrationURL: https:/// www.clini​caltr​ials.gov; Unique identifier: NCT01156116.

Prediction of upper airway dryness and optimal continuous positive airway pressure conditions

Continuous positive airway pressure is the most effective long-term treatment for obstructive sleep apnoea, which is a sleeping disorder characterized by pauses in breathing during sleep. It introduces pressurized atmospheric air into the respiratory system in order to maintain open airways without blockage. Some continuous positive airway pressure devices incorporate a convective heat transfer humidifier to overcome dryness. However, many side effects, including the unacceptable excess of water droplets in the air supply line, have been reported and improvements are essential for better patient’s comfort and acceptance of the therapy. The excess of water droplets is attributed to the qualitative rather than the quantitative approach of determining the rise in temperature and humidity of the inspired air. Therefore, a human upper airway mathematical model is developed to predict the heat and water transfer variation between normal breathing and continuous positive airway pressure conditions and determine the optimal input temperature and relative humidity in the continuous positive airway pressure humidifier.

Improving Airways Patency and Ventilation Through Optimal Positive Pressure Identified by Noninvasive Mechanical Ventilation Titration in Mounier-Kuhn Syndrome: Protocol for an Interventional, Open-Label, Single-Arm Clinical Trial.

BackgroundMounier-Kuhn syndrome or congenital tracheobronchomegaly is a rare disease characterized by dilation of the trachea and the main bronchi within the thoracic cavity. The predominant signs and symptoms of the disease include coughing, purulent and abundant expectoration, dyspnea, snoring, wheezing, and recurrent respiratory infection. Symptoms of the disease in some patients are believed to be pathological manifestations arising due to resident tracheobronchomalacia. Although treatment options used for the management of this disease include inhaled bronchodilators, corticosteroids, and hypertonic solution, there is no consensus on the treatment. The use of continuous positive airway pressure (CPAP) has been reported as a potential therapeutic option for tracheobronchomalacia, but no prospective studies have demonstrated its efficacy in this condition.ObjectiveThe purpose of this is to identify the presence of tracheobronchomalacia and an optimal CPAP pressure that reduces the tracheobronchial collapse in patients with Mounier-Kuhn syndrome and to analyze the repercussion in pulmonary ventilation. In parallel, we aim to evaluate the prevalence of obstructive sleep apnea/hypopnea syndrome.MethodsThis interventional, open-label, single-arm clinical trial will enroll patients who are diagnosed Mounier-Kuhn syndrome. Patient evaluation will be conducted in an outpatient clinic and involve 3 visits. Visit 1 will involve the collection and registration of social demographic, clinical, and functional data. Visit 2 will entail polysomnography, bronchoscopy for the evaluation of tracheobronchomalacia, titration of the optimal pressure that reduces the degree of collapse of the airway, and electrical impedance tomography. In visit 3, patients exhibiting a reduction in collapse areas will be requested to undergo chest computed tomography during inspiration and forced expiration with and without positive pressure (titrated to determine optimal CPAP pressure).ResultsThis protocol is a doctorate project. The project was submitted to the institutional review board on January 24, 2017, and approval was granted on February 2, 2017 (Brazilian Research database number CAAE 64001317.4.000.0068). Patient evaluations started in April 2018. Planned recruitment is based on volunteers’ availability and clinical stability, and interventions will be conducted at least once a month to finish the project at the end of 2020. A preliminary analysis of each case will be performed after each intervention, but detailed results are expected to be reported in the first quarter of 2021.ConclusionsThere is no consensus on the best treatment options for managing Mounier-Kuhn syndrome. The use of positive pressure could maintain patency of the collapsed airways, functioning as a “pneumatic stent” to reduce the degree of airflow obstruction. This, in turn, could promote mobilization of thoracic secretion and improve pulmonary ventilation.Trial RegistrationClinicalTrails.gov NCT03101059; https://clinicaltrials.gov/ct2/show/NCT03101059.International Registered Report Identifier (IRRID)DERR1-10.2196/14786

Factors Affecting Optimal Titration Pressure of Continuous Positive Airway Pressure Device in Patients with Obstructive Sleep Apnea Syndrome.

To assess the effects of anatomical, clinical parameters, and pulmonary respiratory function on the therapeutic titration pressure of continuous positive airway pressure (CPAP) device in obstructive sleep apnea syndrome (OSAS). The study comprised 41 OSAS patients whose optimum CPAP titration pressures were measured. Each patient underwent an otorhinolaryngologic and thoracic examination, and data was recorded for height, weight, body mass index, neck-waist circumferences, Mallampati classification, tonsillar hypertrophy, hypopharyngeal collapse, soft palate-tongue base obstruction scores, peak nasal inspiratory flow and acoustic rhinometry measures, and CPAP device therapeutic pressures. Forced vital capacity, forced expiratory volume, FEV1/FVC ratio and peak expiratory flow values were noted. Median CPAP optimal pressure cut-off value was determined as 9 mmH2O. Statistical analysis was made in two groups as CPAP titration optimal pressure ≤9 and >9 mmH2O. In the optimal pressure >9 group, neck and waist circumferences, hypopharyngeal collapse score, retropalatal and retrolingual lateral wall collapse scores were significantly higher (p<0.05). In multivariate and univariate model analysis, neck and waist circumferences, hypopharyngeal collapse score, retropalatal and retrolingual lateral wall collapse scores were observed to be significant in predicting high and low pressures in univariate model. For the prediction of optimal CPAP titration pressure in OSAS treatment, wide neck and waist circumferences, high hypopharyngeal collapse score and retropalatal and retrolingual lateral wall collapse grades may be determinative.

Predictive equation for optimal continuous positive airway pressure in children with obstructive sleep apnoea.

AimA subgroup of children with obstructive sleep apnoea (OSA) requires treatment with continuous positive airway pressure (CPAP). This study's aims were: 1) to determine if the optimal CPAP for the treatment of OSA in children correlates with body mass index (BMI); 2) to determine the correlation between polysomnographic variables and optimal CPAP in children with OSA; and 3) to develop a CPAP predictive equation for children with OSA.MethodsThis was a retrospective study of children with OSA who underwent CPAP titration studies. Patients with craniofacial abnormalities (except Down syndrome) and neuromuscular diseases were excluded. Polysomnograms were done using Sandman Elite. Correlations between optimal CPAP, clinical and polysomnographic variables were analysed. A multivariable linear regression model for optimal CPAP was developed.Results198 children (mean±sd age 13.1±3.6 years) were studied. Optimal CPAP had a significant positive correlation with age (rho=0.216, p=0.002), obstructive apnoea-hypopnoea index (rho=0.421, p<0.001), 3% oxygen desaturation index (rho=0.417, p<0.001), rapid eye movement respiratory disturbance index (rho=0.378, p<0.001) and BMI z-score (rho=0.160, p=0.024); and a significant negative correlation with arterial oxygen saturation measured by pulse oximetry nadir (rho= −0.333, p<0.001). The predictive equation derived was:Optimal CPAP (cmH2O)=6.486+0.273·age (years)−0.664·adenotonsillectomy(no=1, yes=0)+2.120·Down syndrome (yes=1, no=0)+0.280·BMI z-score.ConclusionThe equation developed may help to predict optimal CPAP in children with OSA. Further studies are required to validate this equation and to determine its applicability in different populations.

Prediction of Optimal CPAP Pressure in Patients with OSAS in Turkish Population

The most effective therapy defined for the patients with obstructive sleep apnea syndrome (OSAS) is the continuous positive airway pressure (CPAP). In this study, we aimed to construct a CPAP prediction formula in Turkish population in order to decrease the requirements for polysomnography (PSG) laboratories. The demographic features, age, gender, weight and height of the participants were recorded at the first visit, together with the neck, waist and hip circumferences. Epworth Sleepiness Scale (ESS) was used to evaluate the levels of daytime sleepiness. All patients underwent at least two PSG studies. In a total of 269 patients with a mean age of 53.42 ±13.32 years were included in the study. In step-wise multiple regression analysis; BMI, AHI, ARI, and neck circumference were the independent predictors of CPAP. A new formula was developed using these values: CPAP pred: (BMI X 0.138) + (AHI X 0.044) + (ARI X 0.056) +(NECK X 0.151) -6.180. The mean CPAP was 7.70 ±2.48 and the mean CPAP pred was 7.71 ±1.53. When the mean CPAP and CPAP pred values were compared, there was not a significant difference with a p value of 0.846. There was a significant correlation between CPAP and CPAP pred values (p:0.001 and r:0.613). We determined that, predicting CPAP with high accuracy may be possible with formulations. These formulations are important in order to reduce the requirements for repeated PSG. Further, larger, prospective studies are required to increase the accuracy of CPAP predicting formulas.

Determination of equation for estimating continuous positive airway pressure in patients with obstructive sleep apnea for the Indian population.

Background:Continuous positive airway pressure (CPAP) is the treatment of obstructive sleep apnea (OSA). The CPAP pressure is generally estimated by manual titration or an auto CPAP device. An alternative method involves the use of the predictive equation.Aim and Objective:There is no equation developed, taking into account the Indian population. The aim is to develop a predictive equation for optimal CPAP pressure in patients with OSA and to validate the equation by comparing it with manual titration pressure.Materials and Methods:A total of 250 patients with OSAS who underwent successful manual titration for CPAP treatment in a tertiary care center were included in this study and divided randomly into two groups A and B with 150 and 100 patients, respectively. Stepwise multiple regression analysis was applied to anthropometric and polysomnographic variables of group A and the predictive equation for estimating CPAP was developed using SPSS. This equation was validated by comparing the estimated pressure with that of manual titration pressure in Group B.Results:The mean age was 55.09 ± 11.43 and mean body mass index (BMI) was 33.69 ± 6.56. CPAP pressure in patients with OSA was 11.13 ± 1.83 cm H2O. The Apnea Hypopnea index (AHI) (r = 0.595, P < 0.001), minimal; SpO2 (r = −0.502, P < 0.001), BMI (r = 0.494, P < 0.001) significantly correlated with optimal CPAP level. A predictive equation for optimal CPAP level in patients with OSA was developed using AHI, BMI, and minimal SpO2, which can be easily measured during the diagnostic process. Optimal CPAP level (cm H2O) =8.401+ (0.053 × BMI) + (0.020 × AHI) − (0.031 × lowest oxygen). Twenty-six percent of the variance in the optimal CPAP level was explained by this equation (R2 = 0.26, P < 0.001) and the equation showed 86% of optimal estimation.Conclusion:The results suggest that manual titration pressure correlates with the pressure derived from the predictive equation in our study.

Dose-dependent effects of mandibular advancement on optimal positive airway pressure requirements in obstructive sleep apnoea.

Implementation of mandibular advancement splint (MAS) therapy as first-line treatment for obstructive sleep apnoea (OSA) is hindered by inter-individual variability of treatment outcomes and lack of robust patient selection methods. Optimal continuous positive airway pressure (CPAP) requirement provides an estimate of airway collapsibility severity, and high CPAP requirements predict MAS therapy failure in retrospective studies. Thus, understanding the effects of mandibular advancement on optimal CPAP requirements may enhance optimisation of patient selection for MAS therapy. This study aims to determine dose-dependent effects of mandibular advancement on optimal CPAP requirements in OSA. Prior to MAS therapy initiation, participants with OSA (apnoea-hypopnea index (AHI) > 10 events/h) underwent a research polysomnogram in which a remotely controlled mandibular positioner (RCMP) was used to determine dose-response effects of varying mandibular advancement positions (0% 'habitual bite' and 25, 50, 75 and 100% of maximum mandibular advancement, in random order) on optimal CPAP requirements. A separate polysomnography determined treatment outcome. Data are presented as mean ± SD or median (1st-3rd quartiles). Seventeen participants (age = 47 ± 9years, body mass index = 26kg/m2 (23-27), apnoea-hypopnea index = 18 events/h (14-44) and minimal oxygen saturation = 84 ± 7%) were studied. Optimal CPAP requirements were reduced with mandibular advancement in a dose-dependent manner (8.9 ± 2.4 vs. 7.9 ± 2.8, 6.4 ± 1.8, 5.7 ± 1.9 and 4.9 ± 1.8cmH2O; respectively, p < 0.0001). Compared with non-responders, responders to MAS therapy had lower AHI, lower arousal index and greater MinSaO2 at baseline. Optimal CPAP requirements at 0% mandibular advancement (or other positions) were not different between groups. Increasing mandibular advancement lowers optimal CPAP requirements in a dose-dependent manner. This supports prior work indicating a beneficial effect of MAS on upper airway collapsibility.