Automatic Derivation of Continuous Positive Airway Pressure Settings: Comparison with In-Laboratory Titration

A Data-Driven Framework for Clinical Decision Support Systems in Positive Airway Pressure and Oxygen Titration

BACKGROUND

Current obstructive sleep apnea treatment relies on manual PAP titration, but it has limitations. Complex interactions during titration and variations in SpO2 data accuracy pose challenges. Patients with co-occurring chronic hypercapnia may require precise oxygen titration. To address these issues, we propose a Clinical Decision Support System using Markov decision processes.

METHODS

This study, compliant with data protection laws, focused on adults with OSA-induced hypoxemia utilizing supplemental oxygen and CPAP/BiPAP therapy. PAP titration, conducted over one night, involved vigilant monitoring of vital signs and physiological parameters. Adjustments to CPAP pressure, potential BiLevel transitions, and supplemental oxygen were precisely guided by patient metrics. Markov decision processes outlined three treatment actions for disorder management, incorporating expert medical insights.

RESULTS

In our study involving 14 OSA patients (average age: 63 years, 27% females, BMI 41 kg m-2), significant improvements were observed in key health parameters after manual titration. The initial AHI of 61.8 events per hour significantly decreased to an average of 18.0 events per hour after PAP and oxygen titration (p < 0.0001), indicating a substantial reduction in sleep-disordered breathing severity. Concurrently, SpO2 levels increased significantly from an average of 79.7% before titration to 89.1% after titration (p < 0.0003). Pearson correlation coefficients demonstrated aggravation of hypercapnia in 50% of patients (N = 5) with initial pCO2 < 55 mmHg during the increase in CPAP pressure. However, transitioning to BiPAP exhibited a reduction in pCO2 levels, showcasing its efficacy in addressing hypercapnia. Simultaneously, BiPAP therapy correlated with a substantial increase in SpO2, underscoring its positive impact on oxygenation in OSA patients. Markov Decision Process analysis demonstrated realistic patient behavior during stable night conditions, emphasizing minimal apnea and good toleration to high CPAP pressure.

CONCLUSIONS

The development of a framework for Markov decision processes of PAP and oxygen titration algorithms holds promise for providing algorithms for improving pCO2 and SpO2 values. While challenges remain, including the need for high-quality data, the potential benefits in terms of patient management and care optimization are substantial, and this approach represents an exciting frontier in the realm of telemedicine and respiratory healthcare.

Relationship between level CPAP titration, anthropometric variables, and drug-induced sleep endoscopy DISE

INTRODUCTION

Subjects with palatal obstruction alone vs. multilevel obstruction on DISE had better outcomes after palate surgery. We asked ourselves if the therapeutic level positive airway pressure (PAP) titration could predict the level of airway obstruction and its complexity.

PURPOSE

The aim of this study was to identify possible relationships between therapeutic level of positive airway pressure initial titration and levels of collapse in drug-induced sleep endoscopy (DISE). A secondary objective was to establish the relationship the other variables and DISE.

METHODS

We analyzed retrospective clinical histories between March 2020 to March 2022 of 37 patients with polysomnography or cardiorespiratory polygraphy studies and PAP initial titration who were taken to drug-induced sleep endoscopy. Sleep study data, anthropometric variables, and patterns of airway collapse during DISE were analyzed with PAP initial titration levels.

RESULTS

Most of the patients with complex collapse had concentric velum collapse (p < 0.006). A significant association was found between the apnea-hypopnea index (AHI) and oropharyngeal collapse; (p < 0.0030) and finally we demonstrated relationship between neck circumference and gender with epiglottis collapse (p < 0.046), (p < 0.037), respectively.

CONCLUSIONS

Our findings show a strong relationship between that complex collapses and concentric velum collapse; patients with greater oropharyngeal collapse have a higher mean AHI. Patients without epiglottic collapse have a higher mean neck circumference. An association between mean pressure initial titration and complex collapse could not be established.

Optimal positive airway pressure requirement and polysomnography indices of obstructive sleep apnea severity in the Saudi population

CONTEXT

Positive airway pressure (PAP) is the first-line therapy for obstructive sleep apnea (OSA). Overnight PAP titration for determining optimal PAP requirements is expensive and often inconvenient. Prediction of optimal PAP requirements from diagnostic polysomnography via mathematical equations is possible but variable across populations.

AIMS

We aimed to (1) determine the optimal PAP requirement, (2) determine differences in optimal PAP requirements across OSA severity groups, (3) determine the relationship between optimal PAP requirement and diagnostic polysomnography measurements of OSA severity, and (4) develop a pilot equation to predict the optimal PAP requirement from diagnostic polysomnography in a sample from the Saudi population.

METHODS

We analyzed records pertaining to adult OSA patients (n = 215; 63% of males) who underwent standardized diagnostic and titration polysomnography in our sleep laboratory between 2015 and 2019. Demographic, anthropometric, and clinical information were also collected for the analysis. Inferential statistics were performed for comparisons between diagnostic and titration studies and between OSA severity groups. Regression analyses were also performed to determine the potential predictors of optimal PAP requirements. Data were presented as the mean (± standard deviation) or median (25th-75th quartiles) according to normality.

RESULTS

The median optimal PAP requirement was 13 (9-17) cmH2O. The optimal PAP requirement was significantly greater for male versus female participants (14 [10-17] vs. 12 [8-16] cmH2O) and for participants with severe OSA (16 [12-20] cmH2O, n = 119) versus those with moderate (11 [8-14] cmH2O, n = 63) or mild (9 [7-12] cmH2O, n = 33) OSA. When combined, nadir oxygen saturation, oxygen desaturation index, and arousal index could be used to predict the optimal PAP requirement (R 2= 0.39, F = 34.0, P < 0.001).

CONCLUSIONS

The optimal PAP requirement in the Saudi population is relatively high and directly correlated with OSA severity. Diagnostic polysomnography measurements of OSA severity predicted the optimal PAP requirement in this sample. Prospective validation is warranted.

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

PURPOSE

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).

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Brazilian Thoracic Association Consensus on Sleep-disordered Breathing

Sleep is essential for the proper functioning of all individuals. Sleep-disordered breathing can occur at any age and is a common reason for medical visits. The objective of this consensus is to update knowledge about the main causes of sleep-disordered breathing in adult and pediatric populations, with an emphasis on obstructive sleep apnea. Obstructive sleep apnea is an extremely prevalent but often underdiagnosed disease. It is often accompanied by comorbidities, notably cardiovascular, metabolic, and neurocognitive disorders, which have a significant impact on quality of life and mortality rates. Therefore, to create this consensus, the Sleep-Disordered Breathing Department of the Brazilian Thoracic Association brought together 14 experts with recognized, proven experience in sleep-disordered breathing.

Titration studies overestimate continuous positive airway pressure requirements in uncomplicated obstructive sleep apnea

STUDY OBJECTIVES

Attended manual CPAP titration is the standard practice for determining optimal positive airway pressures for OSA treatment. However, an unattended single night auto-titrating positive airway pressure (APAP) titration is an alternative. The goal of this study was to determine whether therapeutic CPAP pressures determined during manual titrations are higher than APAP generated surrogate pressures.

METHODS

We conducted a retrospective review of 165 adults with uncomplicated OSA who had full/split-night manual CPAP titrations prior to commencing treatment with APAP. Demographic and clinical data including 30-day APAP compliance data were obtained. We compared the recommended CPAP pressure from manual titrations with the 90th/95th percentile pressure generated from APAP usage over 30 days.

RESULTS

The recommended CPAP pressures during the manual titrations were higher than the 90th/95th percentile pressures generated from APAP. (11.4 ± 3.4 vs. 10.3 ± 2.4, p=0.000). Almost half the group (41.9%) had their manually derived titration pressure at least 1.5 cm above the 90th/95th percentile pressure. In multivariate analyses, BMI was the only variable that predicted higher manual titration pressures. Notably, the average residual AHI on 30-day APAP data was less than the average residual AHI observed at the recommended pressure during the manual titration (5.0 ± 4.3 vs. 7.2 ± 8.5, p= 0.006).

CONCLUSIONS

Manual CPAP titrations may overestimate pressure requirements particularly in patients with higher BMI and may not be necessary in managing patients with uncomplicated OSA. APAP appears to be at least as effective as single pressure CPAP, while delivering lower positive airway pressure.

Alternative Procedure to Individual Nasal Pressure Titration for Sleep Apnea

In the treatment of obstructive sleep apnea (OSA), the current standard of "CPAP titration" in the laboratory or at home is a resource demanding and costly approach that, in developed economies, markedly augments healthcare costs and in low resource economies precludes access to care altogether. Here, we discuss that current guidelines for titration of CPAP could be obviated by taking a different route that in many ways is similar to the institution of treatment in many other medical conditions. To this effect, we present novel population based data from 16,780 patients, showing that after individualized and labor-intensive and expensive CPAP titration, 86.4% of OSA patients are treated with nasal pressure settings within the range of 9 ± 2 cmH₂O, and review the literature to justify the potential adoption of a standard therapeutic CPAP setting as the initial intervention which would be subsequently followed by any necessary adjustments in only a minority of patients who would not derive the necessary benefit from such standardized intervention. Assuming an 80-85% success rate as derived from our analyses, our personal view if extensively adopted could radically reduce healthcare costs and enable markedly improve access to diagnostics.