Respiratory event detection by a positive airway pressure device

Accuracy of residual respiratory event detection by CPAPs: a meta-analysis

PURPOSE

Most continuous positive airway pressure (CPAP) machines have built-in manufacturer-specific proprietary algorithms for automatic respiratory event detection (AED) based on very specific respiratory events scoring criteria. With regards to the accuracy of these data from CPAP machines, evidence from the literature seems conflicting, which formed the basis for this meta-analysis.

METHODS

A meta-analysis was performed on studies that reported Bland-Altman analysis data on agreement (mean bias and limits of agreement [LoA]) of CPAP-determined apnea-hypopnea index (AHI) at therapeutic pressures (AHIFLOW) with that determined from simultaneously conducted polysomnograms (AHIPSG).

RESULTS

In six studies, ResMed CPAPs were used, and in another six studies, Respironics CPAPs were used, while only one study used Fisher & Paykel (F&P) CPAPs. The pooled mean AHI bias from ResMed CPAP studies was - 1.01 with pooled LoAs from - 3.55 to 1.54 (I2 = 17.5%), and from Respironics CPAP studies, pooled mean AHI bias was - 0.59 with pooled LoAs from - 3.22 to 2.05 (I2 = 0%). Pooled percentage errors (corresponding to LoAs) from four ResMed CPAP studies, four Respironics CPAP studies, and the F&P CPAP study were 73%, 59%, and 112%, respectively. A review of the literature for this meta-analysis also revealed lack of uniformity not only in the CPAP manufacturers' respiratory events scoring criteria but also in that used for PSGs across the studies analyzed.

CONCLUSIONS

Even though the pooled results of mean AHI bias suggest good clinical agreement between AHIPSG and AHIFLOW, percentage errors calculated in this meta-analysis indicate the possibility of a significant degree of imprecision in the estimation of AHIFLOW by CPAP machines.

Reliability of respiratory event detection with continuous positive airway pressure in moderate to severe obstructive sleep apnea - comparison of polysomnography with a device-based analysis

PURPOSE

Monitored polysomnography (PSG) is considered the gold standard technique to diagnose obstructive sleep apnea (OSA) and titrate continuous positive airway pressure (CPAP), the accepted primary treatment method. Currently, the American Academy of Sleep Medicine (AASM) considers automatic PAP therapy initiation at home comparable to laboratory titration and recommends telemonitoring-guided interventions. Advanced CPAP devices evaluate and report the residual apnea-hypopnea index (AHI). However, in order to control the effectiveness of the prescribed therapy outside of a PSG setting, the automatic event detection must provide reliable data.

METHODS

A CPAP titration was performed in the sleep laboratory by PSG in patients with OSA. The residual event indices detected by the tested device (prismaLine, Loewenstein Medical Technology) were compared to the manually scored PSG indices. Results of the device (AHIFLOW) were compared according to the AASM scoring criteria 1A (AHI1A, hypopneas with a flow signal reduction of ≥ 30% with ≥ 3% oxygen reduction and/or an arousal) and 1B (AHI1B, hypopneas with a flow signal decrease by ≥ 30% with a ≥ 4% oxygen desaturation).

RESULTS

In 50 patients with OSA, the mean PSG AHI1A was 10.5 ± 13.8/h and the PSG AHI1B was 7.4 ± 12.6/h compared to a mean device AHIFlow of 8.4 ± 10.0/h. The correlation coefficient regarding PSG AHI1A and AHIFlow was 0.968. The correlation regarding central hypopneas on the other hand was 0.153. There were few central events to be compared in this patient group.

CONCLUSION

The device-based analysis showed a high correlation in the determination of residual obstructive AHI under therapy. The recorded residual respiratory event indices in combination with the data about leakage and adherence of the studied device provide reliable information for the implementation and follow-up of CPAP therapy in a typical group of patients with OSA.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT04407949, May 29, 2020, retrospectively registered.

Real-world data evaluation of PAP responsiveness in pediatric obstructive sleep apnea

STUDY OBJECTIVES

The use of positive airway pressure (PAP) in children is a complex process determined by multiple factors. There are limited data on the response of the pediatric population to PAP therapy at home. The goal of the study was to examine real-world responses using PAP home monitoring in children with obstructive sleep apnea.

METHODS

The study included PAP therapy data for 195 children aged between 1 month and 18 years with obstructive sleep apnea and polysomnogram baseline study. We collected demographics, clinical variables, and polysomnogram parameters in all study participants. The individual response to PAP therapy was calculated comparing the apnea-hypopnea index (AHI) in the initial polysomnogram with the mean AHI provided by the download of PAP devices. Multivariate models (logistic regression) were used to examine the predictors of positive PAP response defined as a reduction in AHI ≥ 75%.

RESULTS

We found excellent responses to PAP therapy in children (median 85% AHI reduction). However, there was substantial heterogeneity in AHI reductions while on PAP therapy. The best PAP responses were linked to more severe obstructive sleep apnea and higher PAP levels. We also identified that the response to PAP was higher in obese children and lower in males. The best predictive model for individual PAP response was biological sex, obesity, and obstructive AHI ≥ 20 events/h (area under the receiver operating characteristic curve of 0.791).

CONCLUSIONS

Real-world data show that PAP is overall an effective therapy in children but the response is heterogeneous. Obstructive sleep apnea parameters and individual factors can be used to predict individual AHI reductions while on PAP and optimize PAP responses at home.

CITATION

Aguilar H, Kahanowitch R, Weiss M, et al. Real-world data evaluation of PAP responsiveness in pediatric obstructive sleep apnea. J Clin Sleep Med. 2023;19(7):1313-1319.

Work-Related Sleep Disorders: Causes and Impacts

Insufficient sleep syndrome, shift work disorder, and obstructive sleep apnea (OSA) not only significantly impact the health of affected individuals, but also pose a threat to public safety. This article describes the clinical manifestations and impact of these sleep disorders, particularly as they pertain to workers' health and those with safety-sensitive positions. Sleep deprivation, circadian rhythm disruptions, and excessive daytime sleepiness-hallmarks of insufficient sleep, shift work disorder, and OSA, respectively-all lead to a series of cognitive deficits and impaired concentration that affect workers in a wide variety of fields. We describe the health consequences of these disorders along with treatment strategies, with a focus on current regulatory standards and the under-recognition of OSA in commercial drivers. Given its large scale, there is a need for improved guidelines and regulations for the screening, diagnosis, treatment, and long-term follow-up of OSA in commercial motor vehicle drivers. Increased recognition of the ways in which these sleep disorders impact workers will pave the way for significant improvements in occupational health and safety.

Polysomnographic evaluation of obstructive sleep apnea treatment with fixed pressure CPAP determined by formula

PURPOSE

The use of continuous positive airway pressure (CPAP) is one of the therapeutic modalities for obstructive sleep apnea (OSA). Manual titration polysomnography and the 90th or 95th percentiles of pressure titrated by automatic CPAP (APAP) are the current standard for determining fixed pressure. Pressures programmed at an arbitrary fixed value, or at preset values based on body mass index (BMI) or by predictive formulas, are presented as alternative forms. This study aimed to evaluate the residual apnea-hypopnea index (r-AHI) in polysomnography with CPAP therapy using pressure determined by formula and assess its feasibility to start treatment.

METHODS

Patients referred for CPAP therapy were followed up in three outpatient assessments and underwent polysomnography study with pressure CPAP obtained by formula.

RESULTS

The study sample consisted of 80 patients, 41 women; age 58.6 ± 11.3 years, BMI 34.1 ± 7.5 kg/m² and cervical circumference 42.0 ± 4.2 cm. Most patients (74%) had severe OSA and Epworth sleepiness scale (ESS) of 12.0 ± 5.7 points. The calculated average pressure was 7.8 ± 2.1 cmH₂O. Polysomnography studies showed an r-AHI of 6.1 ± 5.2 events/h and reduction of 84% from baseline AHI. The r-AHI in the REM-supine was 8.4 ± 9.9 events/h. At 30- and 120-day follow-up assessment, adherence to CPAP was 78% and 75% and the ESS score was 6.9 and 6.1 points, respectively.

CONCLUSION

Results suggest that a formula provides an effective initial pressure in the majority of patients (73%). This simplified approach appears to be a viable alternative, with reductions in waiting lists and time from diagnosis to initiation of therapy.

Immediate Physiological Responses to Inspiratory Flow Limited Events in Mild Obstructive Sleep Apnea

Rationale: Inspiratory flow limitation (IFL), characterized by flattening of individual breaths on the airflow/time tracing, is a noninvasive indicator of elevated upper airway resistance. An IFL "event" in isolation has not been defined, nor has the ability to reproducibly identify event occurrence been tested. IFL events and their association with immediate physiological responses-as well as the impact of characteristics such as age, sex, sleep stage, sleepiness, and event duration on their association with such outcomes-have not been studied. Symptomatic patients with a normal to mildly abnormal apnea-hypopnea index who have predominant IFL on their polysomnography may benefit from treatment. Objectives: To test the reproducibility of identifying IFL events and their termination and to determine the frequency of the immediate physiological response to their occurrence, including desaturation, electroencephalography (EEG) arousal, and increased heart rate (HR). Methods: Fifty-eight patients with obstructive sleep apnea (OSA) underwent full diagnostic polysomnography. IFL events and their termination were identified manually using predefined rules from the unscored nasal cannula flow channel alone and were evaluated for responses such as EEG arousal, oxygen desaturation of ⩾3%, and HR increase. Results: Interscorer reliability was acceptable, with an average percent agreement for occurrence of 82% ± 3%. Of all IFL events, 24% (regardless of the definition) were not associated with an EEG arousal, an increase in HR, or O₂ desaturation. Of all IFL events scored, 25% caused O₂ desaturation, 40% were associated with an EEG arousal, and 55% were associated with an increase in HR; 67% caused either an EEG arousal and/or an increase in HR. Responses were observed to occur either in isolation or in combination. IFL events that terminated with at least two non-IFL breaths, one of which had a 200% increase in amplitude, were significantly associated with O₂ desaturation, EEG arousal, and increase in HR compared with events that ended in one non-IFL breath. IFL events that had a >50% reduction in flow amplitude compared with baseline were significantly associated with O₂ desaturation compared with events that had a 30% reduction or less. Conclusions: Most IFL events resulted in immediate physiological responses, and no single consequence reliably occurred after every event. We propose a framework that can incorporate the scoring of IFL events into assessing the diagnosis and severity of OSA and suggest that no single consequence be used to define IFL as a respiratory event. The relationship of IFL events to OSA outcomes remains to be tested.

APAP, BPAP, CPAP, and New Modes of Positive Airway Pressure Therapy

Positive airway pressure (PAP) is the primary treatment of sleep-disordered breathing including obstructive sleep apnea, central sleep apnea, and sleep-related hypoventilation. Just as clinicians use pharmacological mechanism of action and pharmacokinetic data to optimize medication therapy for an individual, understanding how PAP works and choosing the right mode and device are critical to optimizing therapy in an individual patient. The first section of this chapter will describe the technology inside PAP devices that is essential for understanding the algorithms used to control the airflow and pressure. The second section will review how different comfort settings including ramp and expiratory pressure relief and modes of PAP therapy including continuous positive airway pressure (CPAP), autotitrating CPAP, bilevel positive airway pressure, adaptive servoventilation, and volume-assured pressure support control the airflow and pressure. Proprietary algorithms from several different manufacturers are described. This chapter derives its descriptions of algorithms from multiple sources including literature review, manufacture publications and websites, patents, and peer-reviewed device comparisons and from personal communication with manufacturer representatives. Clinical considerations related to the technological aspects of the different algorithms and features will be reviewed.

Quantitative Changes in Muscular and Capillary Oxygen Desaturation Measured by Optical Sensors during Continuous Positive Airway Pressure Titration for Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common sleep disorder, and continuous positive airway pressure (CPAP) is the most effective treatment. Poor adherence is one of the major challenges in CPAP therapy. The recent boom of wearable optical sensors measuring oxygen saturation makes at-home multiple-night CPAP titrations possible, which may essentially improve the adherence of CPAP therapy by optimizing its pressure in a real-life setting economically. We tested whether the oxygen desaturations (ODs) measured in the arm muscle (arm_OD) by gold-standard frequency-domain multi-distance near-infrared spectroscopy (FDMD-NIRS) change quantitatively with titrated CPAP pressures in OSA patients together with polysomnography. We found that the arm_OD (2.08 ± 1.23%, mean ± standard deviation) was significantly smaller (p-value < 0.0001) than the fingertip OD (finger_OD) (4.46 ± 2.37%) measured by a polysomnography pulse oximeter. Linear mixed-effects models suggested that CPAP pressure was a significant predictor for finger_OD but not for arm_OD. Since FDMD-NIRS measures a mixture of arterial and venous OD, whereas a fingertip pulse oximeter measures arterial OD, our results of no association between arm_OD and finger_OD indicate that the arm_OD mainly represented venous desaturation. Arm_OD measured by optical sensors used for wearables may not be a suitable indicator of the CPAP titration effectiveness.

A longitudinal study of the accuracy of positive pressure therapy machine-detected apnea-hypopnea events

STUDY OBJECTIVES

During positive airway pressure (PAP) therapy for sleep apnea syndromes, the machine detected respiratory event index (REI_FLOW) is an important method for clinicians to evaluate the beneficial effects of PAP. There are concerns about the accuracy of this detection, which also confounds a related question-how common and severe are residual events on PAP.

METHODS

Subjects with OSA who underwent a split night polysomnography were recruited prospectively. Those treated with PAP and tracked by the EncoreAnywhere system were analyzed. The ones who stopped PAP within one month were excluded for this analysis. Compliance, therapy data and waveform data were analyzed. Machine detected versus manually scored events were compared at the 1st, 3rd, 6th and 12th month from PAP initiation. Logistic regression was used to determine factors associated with a high REI_FLOW difference.

RESULTS

One hundred and seventy-nine patients with a mean age 59.06 ± 13.97 years old, median body mass index 33.60 (29.75-38.75) kg/m², and median baseline AHI 46.30 (31.50-65.90) times/hour were included. The difference between the machine detected REI_FLOW and manually scored REI_FLOW was 10.72 ±8.43 in the first month and remained stable for up to 12 months. Male sex and large leak ≥ 1.5% were more frequent in patients who had an REI_FLOW difference of ≥ 5 / hour of use. A titration arousal index ≥ 15/ hour of sleep, and higher ratio of unstable to stable breathing were also associated with an REI_FLOW difference ≥ 5 times/hour of use.

CONCLUSIONS

There is a substantial and sustained difference between manual and automated event estimates during PAP therapy, and some associated factors were identified.

Interpreting CPAP device respiratory indices in children

STUDY OBJECTIVES

An increasing number of children with obstructive sleep apnea (OSA) require treatment with continuous positive airway pressure (CPAP). This study aimed to determine whether automatic respiratory indices from a CPAP device accurately predict manually determined respiratory indices derived from overnight polysomnography (PSG) in children.

METHODS

Consecutive children undergoing manual CPAP titration PSG using a ResMed VPAP ST-A (S9) were included. The apnea-hypopnea index (AHI), apnea index (AI), and hypopnea index (HI) from automatic analysis of the CPAP device for that night (AHI_CPAP, AI_CPAP, and HI_CPAP) were compared with manually derived respiratory indices (RDI_PSG, OAHI_PSG, AI_PSG, and HI_PSG) using the Wilcoxon matched-pairs signed-ranks test.

RESULTS

Forty-six children (32 boys; median age, 13.5 years; range, 4.6-20.0 years) were included. There was no difference between RDI_PSG and AHI_CPAP (P = .6) nor between HI_PSG and HI_CPAP (P = .2). AI_PSG was significantly lower than AI_CPAP (mean difference -1.3 events/hr, P < .001). AI_PSG and AI_CPAP were strongly correlated (r² = .72, P < .01), but the CPAP machine overestimated the number of apneas at higher AIs. OAHI_PSG was significantly lower than AHI_CPAP (P = .003) but strongly correlated (r² = .87, P < .01). The CPAP device significantly underestimated the number of hypopneas at higher indices. Using the manually scored OAHI_PSG of ≥5 events/hr to define significant residual OSA, the AHI_CPAP had a high specificity (0.95) but low sensitivity (0.20).

CONCLUSIONS

The ResMed S9 respiratory indices are not accurate enough to guide treatment decisions in children; in particular, they do not rule out the presence of residual OSA in children that remain symptomatic on CPAP. A low AHI_CPAP is reassuring in the context of a stable patient but may miss ongoing hypopneas.

Use of polysomnography and home sleep apnea tests for the longitudinal management of obstructive sleep apnea in adults: an American Academy of Sleep Medicine clinical guidance statement

INTRODUCTION

Obstructive sleep apnea is an important and common disorder with associated health risks. Assuring successful longitudinal management is vital to patient health and sleep-related quality of life. This paper provides guidance from the American Academy of Sleep Medicine (AASM) regarding the use of polysomnography (PSG) and home sleep apnea tests (HSATs) after a diagnosis of obstructive sleep apnea has been established and, in most cases, treatment implemented.

METHODS

The AASM commissioned a task force of five sleep medicine experts. A literature search was conducted to identify studies that included adult patients with OSA who underwent follow-up PSG or an HSAT. The task force developed clinical guidance statements based on a review of these studies and expert opinion. The AASM Board of Directors approved the final clinical guidance statements.

CLINICAL GUIDANCE STATEMENTS

The AASM supports the following clinical guidance statements on indications for follow-up PSG and HSAT in adult patients with OSA. 1. Follow-up PSG or HSAT is not recommended for routine reassessment of asymptomatic patients with obstructive sleep apnea on PAP therapy, however, follow-up PSG or HSAT can be used to reassess patients with recurrent or persistent symptoms, despite good PAP adherence. 2. Follow-up PSG or HSAT is recommended to assess response to treatment with non-PAP interventions. 3. Follow-up PSG or HSAT may be used if clinically significant weight gain or loss has occurred since diagnosis of OSA or initiation of its treatment. 4. Follow-up PSG may be used for reassessment of sleep-related hypoxemia and/or sleep-related hypoventilation following initiation of treatment for OSA. 5. Follow-up PSG or HSAT may be used in patients being treated for OSA who develop or have a change in cardiovascular disease. 6. Follow-up PSG may be used in patients with unexplained PAP device-generated data. The ultimate judgment regarding propriety of any specific care must be made by the clinician, in light of the individual circumstances presented by the patient, available diagnostic tools, accessible treatment options and resources.

Reliability of automatic detection of AHI during positive airway pressure treatment in obstructive sleep apnea patients: A "real-life study"

INTRODUCTION

Automatic event detection (AED) of residual apnea-hypopnea index (AHI) by ventilators is a current practice in sleep and mechanical ventilation Units but this methodology has not been validated in an unselected population of OSA patients. Aim of the present study was to assess in a "real-life" condition the reliability of AED during PAP therapy by the in-built software compared to full polysomnography during follow-up.

METHODS

We enrolled 300 OSA patients (105 F; AHI 45.3 ± 27.8) already on Positive airway pressure (PAP) therapy: 53% of the patients were on CPAP while other modalities were used in the rest of the sample.

RESULTS

Overall, the built-in software identified residual obstructive AHI (AHIPAP) > 5, 10 or 15 in 18.7, 8.6 or 4.6% of patients, respectively. By using AHIPAP, 28.4% of patients were wrongly classified as "well controlled" despite a residual AHIPSG>5 (6% considering a residual AHIVENT >15); 7% of patients were classified as not controlled while AHIPSG was <5 (1.4% considering a residual AHIVENT >15). Type of ventilation, ventilator parameters, adherence to treatment and level of baseline or follow-up Epworth Sleepiness Scale score were similar between groups. The sensitivity and positive predicted values were very low. Positive likelihood ratio appears adequate only for residual AHIPAP ≥10, but negative likelihood ratio was inconclusive for all the cut-off considered.

DISCUSSION

The results of the present study suggest a more cautious approach in the follow-up of OSA patients, since a protocol based only on AED detection and symptoms assessment may not be accurate especially for AHIPAP<15.

Validating respiratory index of auto-titrating positive airway pressure device with polysomnography

PURPOSE

Positive airway pressure (PAP) devices have been widely used as the first line of treatment in obstructive sleep apnea (OSA). Most advanced PAP devices support the estimation of respiratory index (RI) using the patient's mask airflow. In addition to the compliance factor for PAP device use, which is important for monitoring patient sleep health, RI is also becoming important for monitoring. However, there are few reports that validate RI of a PAP device with polysomnography.

METHODS

Between January 2015 and December 2017, 50 participants were enrolled who were diagnosed with OSA and prescribed auto-titration PAP (APAP) devices. The RIs of participants were measured at night using APAP devices, concurrently with electroencephalography, respiratory inductance plethysmography sensors, and other polysomnographic sensors in a sleep laboratory. The respiratory-related data of APAP were prospectively analyzed with the manually scored polysomnographic data.

RESULTS

The apnea-hypopnea index and apnea index showed a statistically close relationship between the auto-scored respiratory data from the APAP device and the manually scored respiratory data from polysomnographic sensors. Obstructive apnea and central apnea indices showed relatively low correlations. The differences between the auto-scored RI and manually scored RI were influenced by BMI, waist circumference, weight, oxygen saturation, and respiratory distress indices of diagnostic polysomnographic factors.

CONCLUSIONS

The RIs of APAP devices have a tendency to be underestimated or mismatched when compared with polysomnography. Sleep specialists are advised to consider additional anthropometric and diagnostic factors to account for these differences during PAP treatment.

Objective adherence to dental device versus positive airway pressure treatment in adults with obstructive sleep apnea

Although mandibular advancement device (MAD) treatment of adults with obstructive sleep apnea (OSA) is generally less efficacious than positive airway pressure (PAP), the two treatments are associated, with similar clinical outcomes. As a sub-analysis of a randomized trial comparing the effect of MAD versus PAP on blood pressure, this study compared objectively measured adherence to MAD versus PAP treatment in adults with OSA. Adults with OSA (age 54.1 ± 11.2 [standard deviation] years, 71.1% male, apnea-hypopnea index 31.6 ± 22.7 events/h) were randomized to MAD (n = 89) or PAP (n = 91) treatment for 3-6 months. Objective adherence was assessed with a thermal sensor embedded in the MAD and a pressure sensor in the PAP unit. In a per protocol analysis, no difference was observed in average daily hours of use over all days in participants on MAD (n = 35, 4.4 ± 2.9 h) versus PAP (n = 51, 4.7 ± 1.6 h, p = .597) treatment when days with missing adherence data were included as no use. MAD was used on a lower percentage of days (62.5 ± 36.4% versus 79.9 ± 19.8%, p = .047), but with greater average daily hours of use on days used (6.4 ± 1.9 h versus 5.7 ± 1.2 h, p = .013). Average daily hours of use in the first week were associated with long-term adherence to MAD (p < .0001) and PAP (p = .0009) treatment. Similar results were obtained when excluding days with missing adherence data. In conclusion, no significant difference was observed in objectively measured average daily hours of MAD and PAP adherence in adults with OSA, despite differences in the patterns of use. MAD adherence in the first week predicted long-term use.

[Adherence and efficacy of long-term PAP therapy in patients with sleep-related breathing disorders associated with cardiac conduction disorders]

AIM

To study the effectiveness of prolonged use of PAP therapy (positive airway pressure therapy) in eliminating sleep respiratory disorders and associated cardiac conduction disturbances.

MATERIALS AND METHODS

We included 21 patients who were examined at the Myasnikov Institute of Clinical Cardiology, National Medical Research Center of Cardiology, regarding cardiac rhythm and conduction disturbances, as well as obstructive sleep apnea and who have been on PAP therapy for more than 12 months. The average age was 66.5 [63.5; 73.2] years, body mass index 33.0 [30.2; 38.5] kg/m2, apnea-hypopnea index 65.0 [59.0; 86.3]/h. At the time of analysis, 15 patients continued to use PAP therapy (mean time of use: 6.0 years [4.7; 9.2]) and 6 patients refused long-term use of PAP therapy, mean time to use PAP therapy until failure amounted to 2.82.1 years.

RESULTS

PAP therapy lead to a persistent decrease in apnea-hypopnea index of 63.6/h to 3.7/h was (p=0.0002). 86% of patients met the criteria for adherence to PAP therapy (use 4 hours/night, more than 70% of nights). Initially, before the use of PAP therapy, all cardiac conduction disorders were during sleep and exceeded 3 seconds, with fluctuations from 3.1 to 10.6 seconds. PAP therapy appeared to be effective in all patients: no asystoles, duration of more than 3 seconds, were detected.

CONCLUSION

In obstructive sleep apnea patients with concomitant nighttime cardiac conduction disturbances, the long-term use of PAP therapy is effective and with good adherence.

Built-in software in children on long-term ventilation in real life practice

Information gathered with built-in software (BIS) on new ventilators allow clinicians to access long-term noninvasive ventilation (LTNIV) data. Nevertheless, few evidence are available in literature that highlight potential strengths and disadvantages of using BIS in pediatrics. We aim to evaluate the use of BIS in a cohort of 90 children on LTNIV in our unit, focusing mainly on adherence, air leaks, and residual sleep events. We found that caregivers' perception of ventilator use is independent from objective adherence (P = .137). Furthermore, we failed to find any predictors of adherence. As regards air leaks, we found that pre-scholars' (0-6 years old) total air leaks are lower than teenagers' (more than 12 years old) (P < .05). Multiple regressive analysis showed that age at the beginning of therapy is a predictor of total air leaks: prescholars are associated with lower values (P < .05), while scholars (6-12 years old) are associated with higher values (P < .05). Finally, we explored the validity of BIS automatic scoring of sleep events (AHI_BIS ) as compared with the manual scoring of polygraphy (AHI_PG ). AHI_BIS is within a range of 3.98 from AHI_PG in 95% of cases, with a 64% of sensitivity and a 67% of specificity in identifying a pathological state. The disagreement between the two methods seems to increase for high AHI values. In conclusion, data gathered by BIS are a useful support tool for the clinician in assessing the course of LTNIV. However, clinicians must be aware of the several limitations of built-in software, especially in pediatrics.

OSA in Professional Transport Operations: Safety, Regulatory, and Economic Impact

OSA is common among commercial vehicle operators (CVOs) in all modes of transportation, including truck, bus, air, rail, and maritime operations. OSA is highly prevalent and increases the risk of drowsiness-related crashes in CVOs. Internationally, specific regulations regarding its identification and management vary widely or do not exist; medical examiners and sleep medicine specialists are urged to use available guidance documents in their absence. Education, screening, prompt identification and treatment, and ongoing surveillance to ensure effective therapy can lower the risk of fatigue-related crashes.

[Telemonitoring in continuous positive airway pressure-treated patients with obstructive sleep apnoea syndrome: An algorithm proposal]

Most of the continuous positive airway pressure (CPAP) devices currently in use allow telemonitoring of observance, leaks and the apnoea-hypopnoea index (AHI). La Société française de recherche et de médecine du sommeil (SFRMS) and La Société de pneumologie de langue française (SPLF) workgroup offer to CPAP prescribers and to home care providers a scientific document which has the following purposes: to underline the relevance of the telemonitoring of leaks and the AHI, to define alert thresholds, to describe the principal mechanisms generating excessive leaks and high AHI, and to propose a diagnostic algorithm.

Baseline Lighter Sleep and Lower Saturation Are Associated With Improved Sleepiness and Adherence on Continuous Rather Than Autotitrating Positive Airway Pressure

The objective was to test whether there were better outcomes on switching from autotitrating positive airway pressure (APAP) to continuous positive airway pressure (CPAP) in a clinic sample of patients with obstructive sleep apnea (OSA). Patients prescribed APAP in 2015-2016 and belonging to a subset characterized by side effects, or suboptimal response or adherence, were advised a switch to CPAP following a CPAP titration polysomnography. The main analysis was for improvement (after switch from APAP to CPAP) in (1) sleepiness, wakefulness inability, and fatigue, using change from baseline in the Sleepiness-Wakefulness Inability and Fatigue Test (delta SWIFT), and Epworth Sleepiness Scale (delta ESS), and (2) adherence using percentage of days with ≥4-hour use and whether there was ≥4-hour use on ≥70% days. To determine possible predictors for switching, additional analysis was performed for differences at baseline between patients switching and those staying on APAP. A total of 148 patients were switched from APAP to CPAP and had greater improvement in delta SWIFT (5.2 vs 4.1, P = .004), greater improvement in delta ESS (3.6 vs 2.9, P = .011), and better adherence (79.4% vs 74.3%, P = .006) on CPAP than on APAP. More patients were adherent on CPAP than on APAP (83.1% vs 68.9%, P = .006). Patients switching had higher baseline arousal index and stage N1 sleep, and lower nadir oxygen saturation, than 96 patients not switching. Thus, there is a subset of patients with better outcomes after switching to CPAP than on APAP. Patients with baseline lighter sleep (indicated by more arousals and stage N1), or greater desaturation, may be more likely to do better on CPAP than on APAP. CPAP may be the preferable treatment in a significant subset of patients. If APAP is used first anyway, side effects, or suboptimal response or adherence, should lead to consideration of switching to CPAP based on a CPAP titration polysomnography.

Improvement in Sleep-Disordered Breathing Indices Downloaded From a Positive Airway Pressure Machine Following Conversion of Atrial Fibrillation to Sinus Rhythm

ABSTRACT

Sleep-disordered breathing (SDB) is a contributor to atrial fibrillation (AF) and treatment of obstructive sleep apnea can reduce the recurrence of AF following catheter ablation. However, the effect of AF therapies on measures of SDB severity is less robustly described. We present the case of a middle-aged man with SDB and persistent AF who exhibited improvement in SDB metrics, as characterized by data downloaded from his auto-titrating continuous positive airway pressure (AutoCPAP) machine, very shortly following procedures that restored sinus rhythm. Between procedures, when his rhythm reverted to AF, the downloaded parameters suggested more SDB events. After catheter ablation, the patient maintained sinus rhythm and the improvement in SDB metrics was sustained as well. This case provides support in favor of a bidirectional relationship between SDB and AF and suggests that data available from PAP machines may be useful in serial assessment of SDB status relative to heart rhythm.

Change in Cognition and Other Non-Motor Symptoms With Obstructive Sleep Apnea Treatment in Parkinson Disease

STUDY OBJECTIVES

Parkinson disease (PD) non-motor symptoms are associated with sleep disorders and impair quality of life. Our objective was to assess the effect of obstructive sleep apnea (OSA) treatment using continuous positive airway pressure (CPAP) on PD non-motor symptoms.

METHODS

In this prospective observational study, 67 patients with idiopathic PD underwent polysomnography. Those with moderate-severe OSA were offered CPAP therapy. Subjects were divided into those without OSA (OSA-), and those with OSA (OSA+). Analyses were conducted for 6 and 12 months' follow-up data. At 6 months, those who had used CPAP at home for at least 1 month were considered CPAP users (OSA+CPAP+), whereas those who did not try it, or declined further treatment following a short trial were considered non-users (OSA+CPAP-). For the 12-month analysis, only those still actively using CPAP at 12 months were included in the OSA+CPAP+ group. Non-motor symptom measurements were: Epworth Sleepiness Scale, Montreal Cognitive Assessment (MoCA), Unified Parkinson's Disease Rating Scale part 1 (UPDRS1), Parkinson's Disease Sleep Scale (PDSS), Fatigue Severity Scale, Apathy Scale, Beck Depression Inventory, and Hospital Anxiety and Depression Scale (HADS).

RESULTS

Sixty-five participants were re-assessed at least once. At 6 months, 30 participants were categorized as OSA+CPAP+, 11 OSA+CPAP-, and 18 OSA-. At 12 months, 21 were categorized as OSA+CPAP+, 21 OSA+CPAP-, and 17 OSA-. The UPDRS1 and PDSS improved from baseline in OSA+CPAP+ at 6 months (-2.7, standard deviation [SD] 4.0, P = .001, and 7.9, SD 19.0, P = .03, respectively) and 12 months (-4.1, SD 5.4, P = .002, and 11.4, SD 24.4, P = .04, respectively), but not in other groups. The MoCA and HADS-A improved in OSA+CPAP+ at 12 months (1.7, SD 3.5, P = .04, and -2.1, SD 3.8, P = .02, respectively). The MoCA improved in those with low baseline MoCA and those with REM sleep behavior disorder. Mean CPAP use in users at 12 months was 3 hours 36 minutes per night.

CONCLUSIONS

CPAP treatment of OSA in PD is associated with improved overall non-motor symptoms, sleep quality, anxiety, and global cognitive function over a 12-month period.

The management, privacy and medico-legal issues of electronic CPAP data in Australia and New Zealand: Electronic CPAP data management in Australia and New Zealand

STUDY OBJECTIVE

Continuous Positive Airway Pressure (CPAP) is considered to be the gold standard treatment for obstructive sleep apnoea (OSA). CPAP monitoring systems allow tracking of patient CPAP adherence and treatment efficacy, by measuring residual sleep-disordered breathing, hours of CPAP use, and mask leak etc. The American Thoracic Society (ATS) published a position paper in 2013 highlighting issues of interpreting CPAP data such as a lack of consistency between CPAP manufacturers data algorithms, legal implications of CPAP data and implications for CPAP adherence. This paper extends on this work by investigating these issues in an Australasian context.

METHOD

A review of current literature on CPAP monitoring systems, privacy and security of CPAP data for major Australasian CPAP providers, and CPAP adherence was undertaken. A legal review was also commissioned for issues related to privacy and security of CPAP data.

RESULTS

CPAP manufacturers' utilize different algorithms for respiratory event detection and clinicians need to be aware the implications for interpreting CPAP data. Australasian CPAP manufacturers have created security/privacy policies with the intent to follow relevant legislation to protect patients' CPAP data, however they do need to be constantly reviewed and updated to avoid data breaches and changes to agreements. No guarantees can be provided by the Australasian Sleep Association on CPAP manufacturers' compliance with these policies and there is the potential for some degree of liability for physicians and CPAP providers associated with CPAP data. Lastly, providing patients with feedback on their CPAP usage and OSA management appears to have positive influence CPAP adherence.

CONCLUSIONS

CPAP data provides many opportunities to increase OSA patient care and to help patients self-manage this chronic condition. However, issues relating to lack of standardization of CPAP parameters, privacy, security, and legal implications will need to be managed in this changing technologic and clinical environment.

Management of Obstructive Sleep Apnea in Commercial Motor Vehicle Operators: Recommendations of the AASM Sleep and Transportation Safety Awareness Task Force

ABSTRACT

The American Academy of Sleep Medicine Sleep and Transportation Safety Awareness Task Force responded to the Federal Motor Carrier Safety Administration and Federal Railroad Administration Advance Notice of Proposed Rulemaking and request for public comments regarding the evaluation of safety-sensitive personnel for moderate-to-severe obstructive sleep apnea (OSA). The following document represents this response. The most salient points provided in our comments are that (1) moderate-to-severe OSA is common among commercial motor vehicle operators (CMVOs) and contributes to an increased risk of crashes; (2) objective screening methods are available and preferred for identifying at-risk drivers, with the most commonly used indicator being body mass index; (3) treatment in the form of continuous positive airway pressure (CPAP) is effective and reduces crashes; (4) CPAP is economically viable; (5) guidelines are available to assist medical examiners in determining whether CMVOs with moderate-to-severe OSA should continue to work without restrictions, with conditional certification, or be disqualified from operating commercial motor vehicles.

A real-world comparison of apnea-hypopnea indices of positive airway pressure device and polysomnography

The apnea hypopnea index (AHI) reported by positive airway pressure (PAP) device is widely used in clinical practice, yet its correlation with standardized AHI obtained during the sleep study is not established. The current study was conducted to investigate the correlation between AHI estimated by the PAP device and reported on the smart card with the AHI found during the PAP polysomnography (PSG) in the “real world” setting at an academic sleep center. We retrospectively reviewed the medical records of 280 patients who underwent a PAP titration PSG at Drexel sleep center, and were later prescribed a PAP device. The AHI was categorized in clinically relevant subgroups (as AHI ≤5 and AHI >5). The AHI at the final pressure on the PSG and the average AHI from the prescribed PAP device were compared. The results showed that in the majority (77.3%) of patients (126 of 163), the AHI from both PAP device and PSG correlated well and were in the same category (AHI ≤5 and AHI >5 respectively). The majority of patients (80.7%) with PSG AHI of <5 had PAP device AHI <5 as well. By contrast, if PSG AHI was >5, 61.5% patients reported good control, with AHI <5 on PAP device AHI. We conclude that in a majority of patients who were optimally titrated in the sleep laboratory, the PAP device continued to show optimal control at home.

Validation of the System One RemStar Auto A-Flex for Obstructive Sleep Apnea Treatment and Detection of Residual Apnea-Hypopnea Index: A European Randomized Trial

STUDY OBJECTIVES

Autotitrating continuous positive airway pressure (CPAP) devices adjust pressure in response to changes in airflow and are an alternative to attended in-laboratory titration polysomnography (PSG) to determine optimal pressure levels. The aim of this study was to compare the performance of the System One RemStar Auto A-Flex (Philips Respironics, Murrysville, PA, USA) automatically adjusted positive airway pressure (APAP) mode to manually titrated, fixed pressure CPAP and to validate the device's breathing event detection capabilities against attended in-laboratory PSG.

METHODS

Sixty-one patients investigated in five centers for moderate to severe obstructive sleep apnea between May 2012 and June 2013 were invited to participate. Participants underwent two full-night attended polysomnograms in random order with manually titrated, fixed pressure CPAP versus APAP.

RESULTS

Fifty-three participants with a mean apnea-hypopnea index (AHI) of 45.9 ± 23 completed two sleep studies and were included in the analysis. There were significant but not clinically relevant differences between APAP and CPAP respectively: Apnea index [1.0 (2.8 ± 0.8), median (mean ± standard deviation)] versus [1.8 (5.3 ± 11.5)], p = 0.004; percentage of N1 sleep [12.3 (15.9 ± 0.5)] versus [14.3 (18.9 ± 12.7)], p = 0.028. AHI values differed between PSG [2.8 (5.5. ± 9.3)] and device [3.7 (6.0 ± 8.6)], p = 0.003). Regarding residual events detection, intraclass correlation coefficients for AHI were strong (0.956, p < 0.001) and the area under the curve was 0.988 (AHI cut-off value of 10).

CONCLUSIONS

The new APAP modality was effective and residual apnea-hypopnea indices calculated by the device strongly correlated to those assessed by PSG.

COMMENTARY

A commentary on this article appears in this issue on page 167.

A new predictive model for continuous positive airway pressure in the treatment of obstructive sleep apnea

BACKGROUND

Numerous mathematical formulas have been developed to determine continuous positive airway pressure (CPAP) without an in-laboratory titration study. Recent studies have shown that style of CPAP mask can affect the optimal pressure requirement. However, none of the current models take mask style into account. Therefore, the goal of this study was to develop new predictive models of CPAP that take into account the style of mask interface.

METHODS

Data from 200 subjects with attended CPAP titrations during overnight polysomnograms using nasal masks and 132 subjects using oronasal masks were randomized and split into either a model development or validation group. Predictive models were then created in each model development group and the accuracy of the models was then tested in the model validation groups.

RESULTS

The correlation between our new oronasal model and laboratory determined optimal CPAP was significant, r = 0.61, p < 0.001. Our nasal formula was also significantly related to laboratory determined optimal CPAP, r = 0.35, p < 0.001. The oronasal model created in our study significantly outperformed the original CPAP predictive model developed by Miljeteig and Hoffstein, z = 1.99, p < 0.05. The predictive performance of our new nasal model did not differ significantly from Miljeteig and Hoffstein's original model, z = -0.16, p < 0.90. The best predictors for the nasal mask group were AHI, lowest SaO2, and neck size, whereas the top predictors in the oronasal group were AHI and lowest SaO2.

CONCLUSION

Our data show that predictive models of CPAP that take into account mask style can significantly improve the formula's accuracy. Most of the past models likely focused on model development with nasal masks (mask style used for model development was not typically reported in previous investigations) and are not well suited for patients using an oronasal interface. Our new oronasal CPAP prediction equation produced significantly improved performance compared to the well-known Miljeteig and Hoffstein formula in patients titrated on CPAP with an oronasal mask and was also significantly related to laboratory determined optimal CPAP.

Sleep remains disturbed in patients with obstructive sleep apnea treated with positive airway pressure: a three-month cohort study using continuous actigraphy

OBJECTIVE

Some patients with obstructive sleep apnea (OSA) remain sleepy despite positive airway pressure (PAP) therapy. The mechanisms by which this occurs are unclear but could include persistently disturbed sleep. The goal of this study was to explore the relationships between subjective sleepiness and actigraphic measures of sleep during the first three months of PAP treatment.

METHODS

We enrolled 80 patients with OSA and 50 comparison subjects prior to treatment and observed them through three months of PAP therapy. PAP adherence and presence of residual respiratory events were determined from PAP machine downloads. Epworth Sleepiness Scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ), and actigraphic data were collected before and at monthly intervals after starting PAP.

RESULTS

Patients with OSA were sleepier and showed a greater degree of sleep disruption by actigraphy at the baseline. After three months of PAP, only ESS and number of awakenings (AWAKE#) normalized, while wake after sleep onset and sleep efficiency remained worse in patients with OSA. FOSQ was improved in patients with OSA but never reached the same level as that of comparison subjects. ESS and FOSQ improved slowly over the study period.

CONCLUSIONS

As a group, patients with OSA show actigraphic evidence of persistently disturbed sleep and sleepiness-related impairments in day-to-day function after three months of PAP therapy. Improvements in sleepiness evolve over months with more severely affected patients responding quicker. Persistent sleep disruption may partially explain residual sleepiness in some PAP-adherent OSA patients.

Residual Events during Use of CPAP: Prevalence, Predictors, and Detection Accuracy

STUDY OBJECTIVES

To assess the frequency, severity, and determinants of residual respiratory events during continuous positive airway therapy (CPAP) for obstructive sleep apnea (OSA) as determined by device output.

METHODS

Subjects were consecutive OSA patients at an American Academy of Sleep Medicine accredited multidisciplinary sleep center. Inclusion criteria included CPAP use for a minimum of 3 months, and a minimum nightly use of 4 hours. Compliance metrics and waveform data from 217 subjects were analyzed retrospectively. Events were scored manually when there was a clear reduction of amplitude (≥ 30%) or flow-limitation with 2-3 larger recovery breaths. Automatically detected versus manually scored events were subjected to statistical analyses included Bland-Altman plots, correlation coefficients, and logistic regression exploring predictors of residual events.

RESULTS

The mean patient age was 54.7 ± 14.2 years; 63% were males. All patients had a primary diagnosis of obstructive sleep apnea, 26% defined as complex sleep apnea. Residual flow measurement based apnea-hypopnea index (AHIFLOW) > 5, 10, and 15/h was seen in 32.3%, 9.7%, and 1.8% vs. 60.8%, 23%, and 7.8% of subjects based on automated vs. manual scoring of waveform data. Automatically detected versus manually scored average AHIFLOW was 4.4 ± 3.8 vs. 7.3 ± 5.1 per hour. In a logistic regression analysis, the only predictors for a manual AHIFLOW > 5/h were the absolute central apnea index (CAI), (odds ratio [OR]: 1.5, p: 0.01, CI: 1.1-2.0), or using a CAI threshold of 5/h of sleep (OR: 5.0, p: < 0.001, CI: 2.2-13.8). For AHIFLOW > 10/h, the OR was 1.14, p: 0.03 (CI: 1.1-1.3) per every CAI unit of 1/hour.

CONCLUSIONS

Residual respiratory events are common during CPAP treatment, may be missed by automated device detection and predicted by a high central apnea index on the baseline diagnostic study. Direct visualization of flow data is generally available and improves detection.

All APAPs Are Not Equivalent for the Treatment of Sleep Disordered Breathing: A Bench Evaluation of Eleven Commercially Available Devices

STUDY OBJECTIVES

This study challenged on a bench-test the efficacy of auto-titrating positive airway pressure (APAP) devices for obstructive sleep disordered breathing treatment and evaluated the accuracy of the device reports.

METHODS

Our bench consisted of an active lung simulator and a Starling resistor. Eleven commercially available APAP devices were evaluated on their reactions to single-type SDB sequences (obstructive apnea and hypopnea, central apnea, and snoring), and to a long general breathing scenario (5.75 h) simulating various SDB during four sleep cycles and to a short scenario (95 min) simulating one sleep cycle.

RESULTS

In the single-type sequence of 30-minute repetitive obstructive apneas, only 5 devices normalized the airflow (> 70% of baseline breathing amplitude). Similarly, normalized breathing was recorded with 8 devices only for a 20-min obstructive hypopnea sequence. Five devices increased the pressure in response to snoring. Only 4 devices maintained a constant minimum pressure when subjected to repeated central apneas with an open upper airway. In the long general breathing scenario, the pressure responses and the treatment efficacy differed among devices: only 5 devices obtained a residual obstructive AHI < 5/h. During the short general breathing scenario, only 2 devices reached the same treatment efficacy (p < 0.001), and 3 devices underestimated the AHI by > 10% (p < 0.001). The long scenario led to more consistent device reports.

CONCLUSION

Large differences between APAP devices in the treatment efficacy and the accuracy of report were evidenced in the current study.

Detection of upper airway status and respiratory events by a current generation positive airway pressure device

STUDY OBJECTIVES

To compare a positive airway pressure (PAP) device's detection of respiratory events and airway status during device-detected apneas with events scored on simultaneous polysomnography (PSG).

DESIGN

Prospective PSGs of patients with sleep apnea using a new-generation PAP device.

SETTINGS

Four clinical and academic sleep centers.

PATIENTS

Forty-five patients with obstructive sleep apnea (OSA) and complex sleep apnea (Comp SA) performed a PSG on PAP levels adjusted to induce respiratory events.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

PAP device data identifying the type of respiratory event and whether the airway during a device-detected apnea was open or obstructed were compared to time-synced, manually scored respiratory events on simultaneous PSG recording. Intraclass correlation coefficients between device-detected and PSG scored events were 0.854 for apnea-hypopnea index (AHI), 0.783 for apnea index, 0.252 for hypopnea index, and 0.098 for respiratory event-related arousals index. At a device AHI (AHIFlow) of 10 events/h, area under the receiver operating characteristic curve was 0.98, with sensitivity 0.92 and specificity 0.84. AHIFlow tended to overestimate AHI on PSG at values less than 10 events/h. The device detected that the airway was obstructed in 87.4% of manually scored obstructive apneas. Of the device-detected apneas with clear airway, a minority (15.8%) were manually scored as obstructive apneas.

CONCLUSIONS

A device-detected apnea-hypopnea index (AHIFlow) < 10 events/h on a positive airway pressure device is strong evidence of good treatment efficacy. Device-detected airway status agrees closely with the presumed airway status during polysomnography scored events, but should not be equated with a specific type of respiratory event.

Home-use servo-ventilation therapy in chronic pain patients with central sleep apnea: initial and 3-month follow-up

PURPOSE

Opioid treatment of non-malignant chronic pain can result in hypoxemia, hypercarbia, and central sleep apnea. The aim of this study was to determine the initial efficacy of auto servo-ventilation (ASV) and after 3 months of home use.

METHODS

This prospective multicenter interventional study recruited chronic pain patients prescribed ≥100 morphine equivalents for at least 4 months.

PARTICIPANTS

Following full-night polysomnography (PSG) to confirm the presence of sleep-disordered breathing, patients were randomized to three additional full-night-attended PSGs with continuous positive airway pressure (CPAP), ASV, and servo-ventilation with an initial mandatory pressure support of 6 cm H2O (ASV manual PSmin 6). Following the PSGs, patients were sent home with EncoreAnywhere and ASV with or without mandatory pressure support.

RESULTS

Based on the initial PSG studies, CPAP improved but did not normalize the apnea-hypopnea index (AHI), central apnea index (CAI), or hypopnea index (HI), as all remained elevated. Clinically significant reductions were noted after just one night of ASV and ASV manual (PSmin 6). After 3 months of ASV home use, the AHI, CAI, and obstructive apnea index (OAI) were significantly reduced when compared to baseline diagnostic levels and even when compared to respiratory disturbance indices with CPAP treatment.

CONCLUSIONS

Initial and home use of ASV for 3 months resulted in significantly lower AHI, CAI, and OAI. This reduction attests to the efficacy of ASV treatment in chronic pain patients on high doses of opioids.

Auto-adjusting positive airway pressure treatment for sleep apnea diagnosed by home sleep testing

STUDY OBJECTIVES

Compare auto-adjusting positive airway pressure (APAP) treatment with positive airway pressure (PAP) titration by polysomnography (PSG) followed by CPAP treatment in patients diagnosed with obstructive sleep apnea (OSA) by home sleep apnea testing (HSAT).

DESIGN

Prospective randomized treatment study.

SETTING

Tertiary Veterans Administration Medical Center.

PARTICIPANTS

156 patients diagnosed with OSA by HSAT (apneahypopnea index [AHI] ≥ 10/h) suitable for APAP treatment.

INTERVENTIONS

APAP arm: Treatment with an APAP device, CPAP arm: PSG PAP titration followed by CPAP treatment.

MEASUREMENTS

Mean PAP adherence, Epworth sleepiness scale (ESS), Functional Outcomes of Sleep Questionnaire (FOSQ).

RESULTS

The mean (± SD) age, BMI, and diagnostic AHI (APAP: 28.6 ± 18.5, CPAP: 28.3 ± 16.0/h, p = NS) did not differ between the study arms. After 6 weeks of treatment, 84.6% of 78 patients started on APAP and 84.3% of 70 patients started on CPAP (8 declined treatment after the titration) were using PAP, p = NS. The 90% APAP and level of CPAP were similar (10.8 ± 3.1, 11.7 ± 2.5 cm H2O, p = 0.07). The average nightly PAP use did not differ (APAP: 4.45 ± 2.3, CPAP: 4.0 ± 2.3 h, p = NS). The improvements in the ESS (APAP: -4.2 ± 4.7, CPAP: -3.7 ± 4.8, p = NS) and in the FOSQ (APAP: 2.6 ± 3.5, CPAP: 2.2 ± 3.7, p = NS) were not different.

CONCLUSIONS

Following diagnosis of OSA by HSAT, treatment with APAP results in equivalent PAP adherence and improvement in sleepiness compared to a PSG titration and CPAP treatment.

COMMENTARY

A commentary on this article appears in this issue on page 1277.

Does Positive Airway Pressure Therapy Result in Improved Sleep Quality?

INTRODUCTION

Positive airway pressure (PAP) therapy is the gold-standard for obstructive sleep apnea (OSA) management. While it is known that PAP is efficacious for controlling breathing events during sleep when it is worn at the right pressure for the amount of time prescribed, there is less clear data on how well it improves sleep quality. There are few studies that have examined the effectiveness of PAP therapy on sleep quality.

METHODS

OSA participants (n = 241) from a larger trial examining a PAP adherence were included. Participants were provided with PAP instruction and followed at 2 months and 4 months. PAP adherence was measured as the number of hours per night at prescribed pressure, an objective measure of treatment adherence. The Pittsburgh Sleep Quality Index (PSQI) was used as the primary measure of sleep quality.

RESULTS

The PSQI was significantly correlated with PAP adherence at both the 2-month and 4-month time points, such that lower sleep quality was associated with lower PAP use. This finding held for the sleep disturbance subscale of the PSQI. Over 55% of those using PAP therapy at the 4-month time point continued to report significantly disturbed sleep.

DISCUSSION

This study shows that PAP therapy does not appear to improve sleep quality to a degree that would be expected. Over half of those patients using PAP therapy still experienced disturbed sleep. Whether the disturbed sleep is directly attributable to the PAP device itself or to disturbed sleep secondary to uncontrolled OSA when PAP is not worn is worthy of further investigation.

Improvements in current treatments and emerging therapies for adult obstructive sleep apnea

Obstructive sleep apnea (OSA) is common and is associated with a number of adverse outcomes, including an increased risk for cardiovascular disease. Typical treatment approaches, including positive airway pressure, oral appliances, various upper airway surgeries, and/or weight loss, can improve symptoms and reduce the severity of disease in select patient groups. However, these approaches have several potential limitations, including suboptimal adherence, lack of suitability for all patient groups, and/or absence of adequate outcomes data. Emerging potential therapeutic options, including nasal expiratory positive airway pressure (PAP), oral negative pressure, upper airway muscle stimulation, and bariatric surgery, as well as improvements in existing treatments and the utilization of improving technologies are moving the field forward and should offer effective therapies to a wider group of patients with OSA.

Symptoms of insomnia among patients with obstructive sleep apnea before and after two years of positive airway pressure treatment

STUDY OBJECTIVES

To assess the changes of insomnia symptoms among patients with obstructive sleep apnea (OSA) from starting treatment with positive airway pressure (PAP) to a 2-y follow-up.

DESIGN

Longitudinal cohort study.

SETTING

Landspitali--The National University Hospital of Iceland.

PARTICIPANTS

There were 705 adults with OSA who were assessed prior to and 2 y after starting PAP treatment.

INTERVENTION

PAP treatment for OSA.

MEASUREMENTS AND RESULTS

All patients underwent a medical examination along with a type 3 sleep study and answered questionnaires on health and sleep before and 2 y after starting PAP treatment. The change in prevalence of insomnia symptoms by subtype was assessed by questionnaire and compared between individuals who were using or not using PAP at follow-up. Symptoms of middle insomnia were most common at baseline and improved significantly among patients using PAP (from 59.4% to 30.7%, P < 0.001). Symptoms of initial insomnia tended to persist regardless of PAP treatment, and symptoms of late insomnia were more likely to improve among patients not using PAP. Patients with symptoms of initial and late insomnia at baseline were less likely to adhere to PAP (odds ratio [OR] 0.56, P = 0.007, and OR 0.53, P < 0.001, respectively).

CONCLUSION

Positive airway pressure treatment significantly reduced symptoms of middle insomnia. Symptoms of initial and late insomnia, however, tended to persist regardless of positive airway pressure treatment and had a negative effect on adherence. Targeted treatment for insomnia may be beneficial for patients with obstructive sleep apnea comorbid with insomnia and has the potential to positively affect adherence to positive airway pressure.

Comparing methods of respiratory event detection during the treatment of obstructive sleep apnea

Renewed focus on comparative effectiveness research presents a unique opportunity to develop optimal clinical management pathways for patients with obstructive sleep apnea. With this momentum comes the challenge of measuring treatment effect on sleep-disordered breathing, especially in large, multisite studies. In-laboratory polysomnography, the current gold standard sleep assessment of obstructive sleep apnea severity, is costly and imposes significant participant burden. Alternatives include home unattended sleep testing and overnight pulse oximetry recording. Research studies using positive airway pressure treatment have the additional option of using the information recorded by the patient's positive airway pressure device to assess treatment effectiveness. Recent research has shown relatively good agreement between manual identification of residual respiratory events in overnight in-laboratory polysomnography and the automatic event detection utilized in positive airway pressure machines. In addition to assessing the effects of interventions on sleep disordered breathing, obstructive sleep apnea-related comparative effectiveness studies need to assess the impact of the interventions on patient burden, cost of therapy, timeliness of care, improved quality of life and other clinically relevant outcomes.

An official American Thoracic Society statement: continuous positive airway pressure adherence tracking systems. The optimal monitoring strategies and outcome measures in adults

BACKGROUND

Continuous positive airway pressure (CPAP) is considered the treatment of choice for obstructive sleep apnea (OSA), and studies have shown that there is a correlation between patient adherence and treatment outcomes. Newer CPAP machines can track adherence, hours of use, mask leak, and residual apnea-hypopnea index (AHI). Such data provide a strong platform to examine OSA outcomes in a chronic disease management model. However, there are no standards for capturing CPAP adherence data, scoring flow signals, or measuring mask leak, or for how clinicians should use these data.

METHODS

American Thoracic Society (ATS) committee members were invited, based on their expertise in OSA and CPAP monitoring. Their conclusions were based on both empirical evidence identified by a comprehensive literature review and clinical experience.

RESULTS

CPAP usage can be reliably determined from CPAP tracking systems, but the residual events (apnea/hypopnea) and leak data are not as easy to interpret as CPAP usage and the definitions of these parameters differ among CPAP manufacturers. Nonetheless, ends of the spectrum (very high or low values for residual events or mask leak) appear to be clinically meaningful.

CONCLUSIONS

Providers need to understand how to interpret CPAP adherence tracking data. CPAP tracking systems are able to reliably track CPAP adherence. Nomenclature on the CPAP adherence tracking reports needs to be standardized between manufacturers and AHIFlow should be used to describe residual events. Studies should be performed examining the usefulness of the CPAP tracking systems and how these systems affect OSA outcomes.

Bench test evaluation of adaptive servoventilation devices for sleep apnea treatment

RATIONALE

Adaptive servoventilation devices are marketed to overcome sleep disordered breathing with apneas and hypopneas of both central and obstructive mechanisms often experienced by patients with chronic heart failure. The clinical efficacy of these devices is still questioned.

STUDY OBJECTIVES

This study challenged the detection and treatment capabilities of the three commercially available adaptive servoventilation devices in response to sleep disordered breathing events reproduced on an innovative bench test.

METHODS

The bench test consisted of a computer-controlled piston and a Starling resistor. The three devices were subjected to a flow sequence composed of central and obstructive apneas and hypopneas including Cheyne-Stokes respiration derived from a patient. The responses of the devices were separately evaluated with the maximum and the clinical settings (titrated expiratory positive airway pressure), and the detected events were compared to the bench-scored values.

RESULTS

The three devices responded similarly to central events, by increasing pressure support to raise airflow. All central apneas were eliminated, whereas hypopneas remained. The three devices responded differently to the obstructive events with the maximum settings. These obstructive events could be normalized with clinical settings. The residual events of all the devices were scored lower than bench test values with the maximum settings, but were in agreement with the clinical settings. However, their mechanisms were misclassified.

CONCLUSION

The tested devices reacted as expected to the disordered breathing events, but not sufficiently to normalize the breathing flow. The device-scored results should be used with caution to judge efficacy, as their validity depends upon the initial settings.

Accuracy of positive airway pressure device-measured apneas and hypopneas: role in treatment followup

Improved data transmission technologies have facilitated data collected from positive airway pressure (PAP) devices in the home environment. Although clinicians' treatment decisions increasingly rely on autoscoring of respiratory events by the PAP device, few studies have specifically examined the accuracy of autoscored respiratory events in the home environment in ongoing PAP use. “PAP efficacy” studies were conducted in which participants wore PAP simultaneously with an Embletta sleep system (Embla, Inc., Broomfield, CO), which was directly connected to the ResMed AutoSet S8 (ResMed, Inc., San Diego, CA) via a specialized cable. Mean PAP-scored Apnea-Hypopnea Index (AHI) was 14.2 ± 11.8 (median: 11.7; range: 3.9–46.3) and mean manual-scored AHI was 9.4 ± 10.2 (median: 7.7; range: 1.2–39.3). Ratios between the mean indices were calculated. PAP-scored HI was 2.0 times higher than the manual-scored HI. PAP-scored AHI was 1.5 times higher than the manual-scored AHI, and PAP-scored AI was 1.04 of manual-scored AI. In this sample, PAP-scored HI was on average double the manual-scored HI. Given the importance of PAP efficacy data in tracking treatment progress, it is important to recognize the possible bias of PAP algorithms in overreporting hypopneas. The most likely cause of this discrepancy is the use of desaturations in manual hypopnea scoring.