Follow-up assessment of CPAP efficacy in patients with obstructive sleep apnea using an ambulatory device based on peripheral arterial tonometry

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.

Correlations between home sleep apnea tests and polysomnography outcomes do not fully reflect the diagnostic accuracy of these tests

STUDY OBJECTIVES

The clinical performance of home sleep apnea tests (HSATs) can be described by their (diagnostic) accuracy, defined as the percentage agreement with the obstructive sleep apnea severity category (normal, mild, moderate, and severe) based on polysomnography. Rather than reporting on accuracy, there has been a strong reliance in the literature to report correlation coefficients between the apnea-hypopnea index of HSATs and polysomnography to support claims of diagnostic performance. This is surprising, as it has been well described that correlation coefficients are inadequate to evaluate equivalence between 2 parameters. The aim of this study was to systematically investigate the magnitude of the discrepancies between correlation coefficients and diagnostic accuracy reported in or retrievable from HSAT validation studies.

METHODS

We compared the discrepancy between accuracy and apnea-hypopnea index correlation coefficients of all validation papers that met the inclusion criteria. A total of 20 papers were retained, representing a participant pool of 1,652.

RESULTS

The weighted average apnea-hypopnea index correlation across all 20 papers was 0.82 and the weighted average accuracy was 0.61, highlighting a discrepancy of 0.21 and an overall misdiagnosis rate of 39%.

CONCLUSIONS

The results of our study confirm the need for increased scientific rigor in selecting primary performance endpoints to support clinical performance claims of HSATs.

CITATION

Massie F, Van Pee B, Bergmann J. Correlations between home sleep apnea tests and polysomnography outcomes do not fully reflect the diagnostic accuracy of these tests. J Clin Sleep Med. 2022;18(3):871-876.

Use of the WatchPAT to detect occult residual sleep-disordered breathing in patients on CPAP for obstructive sleep apnea

STUDY OBJECTIVES

To determine the accuracy of the apnea-hypopnea index (AHI) as measured by continuous positive airway pressure (CPAP) machines by simultaneously employing a home sleep apnea testing device (WatchPAT 200, Itamar Medical, Israel [WPAT]) in patients suspected of having residual sleep-disordered breathing (SDB).

METHODS

Patients with new, recurrent, or worsening signs, symptoms, or comorbidities associated with obstructive sleep apnea underwent home sleep apnea testing using WPAT while simultaneously using CPAP at their usual prescribed settings. CPAP AHI and WPAT AHI, respiratory disturbance index, and oximetry readings were then compared.

RESULTS

We identified an elevated AHI with WPAT testing in nearly half of patients with clinically suspected residual SDB and a normal CPAP AHI. WPAT detected additional respiratory events as well, including rapid eye movement-related apneas, respiratory effort-related arousals, and hypoxemia.

CONCLUSIONS

WPAT AHI was significantly higher than simultaneous CPAP AHI in nearly half of those patients with clinically suspected residual SDB being treated with CPAP. Additional respiratory disturbances, including rapid eye movement-related respiratory events, respiratory effort-related arousals, and hypoxemia, were elucidated only with the use of the WPAT. Residual SDB may have potential clinical consequences, including reduced CPAP adherence, ongoing hypersomnolence, and other health-related sequelae. Simultaneous WPAT testing of patients with a normal CPAP AHI may represent a valuable tool to detect clinically suspected residual SDB or to ensure adequate treatment in high-risk patients with obstructive sleep apnea in general.

The Interaction Between Craniofacial Computed Tomographic Dimensional Parameters and BMI in Obstructive Sleep Apnea

Introduction

The impact of the dimensional parameters of the pharyngeal bony frame by its length, width and the position of the hyoid upon the severity of obstructive sleep apnea syndrome (OSAS) has not been investigated in depth. Interactions of those parameters with body mass index (BMI) and their overall reciprocal effect on OSAS severity have also not been established.

Materials and Methods

This retrospective cross-sectional study was conducted on 108 male OSAS patients followed in OSAS outpatient clinics between November 2014 and October 2015. They all underwent a polysomnography test, and an apnea-hypopnea index (AHI) was calculated. They also underwent an upper airway computerized tomographic scan in which three craniofacial parameters were evaluated: inter-pterygoid distance (IPD), hard palate-to-hyoid (HP-H) distance, and gnathion plane-to-hyoid (GP-H) distance.

Results

A longer pharynx and an inferiorly placed hyoid bone correlated with the AHI (r = 0.33, p = 0.001 and r = 0.226, p = 0.03, respectively). GP-H correlated with body mass index (BMI) (r = 0.3243, p < 0.001), while HP-H and IPD did not. We found an interaction between BMI and HP-H, but none between GP-H and BMI. IPD did not correlate with OSAS severity, but it correlates with the age of the OSAS patients (r = 0.235, p = 0.015).

Conclusion

Pharynx length and hyoid position have significant effects upon OSAS severity, and they interact differently with BMI in terms of those effects. Hard palate width increases with age but has no correlation with OSAS severity.

Impact of Arterial Stiffness on WatchPAT Variables in Patients With Obstructive Sleep Apnea

STUDY OBJECTIVES

The WatchPAT is a wrist-worn portable device that creates integration data regarding peripheral arterial tone (PAT), oxyhemoglobin saturation, heart rate, and actigraphy to diagnose or screen for obstructive sleep apnea (OSA). Previous studies have demonstrated the efficacy and validity of respiratory variables measured by the WatchPAT compared to those using polysomnography (PSG). However, the effects of arterial stiffness or atherosclerosis on WatchPAT parameters remain to be elucidated.

METHODS

Sixty-one consecutive patients with suspected OSA who underwent home-based testing with the WatchPAT 200, standard in-laboratory overnight polysomnography (PSG), and pulse wave velocity (PWV) as an index of arterial stiffness were studied. All PSG recordings were scored manually using the American Academy of Sleep Medicine criteria, whereas WatchPAT data were analyzed by an automatic algorithm. We evaluated how arterial stiffness affected respiratory event index data in WatchPAT (WP-AHI), because WP-AHI could be partly influenced by PAT, comparing WP-AHI and the apneahypopnea index measured by PSG (PSG-AHI) in consideration of PWV result.

RESULTS

Overall, WP-AHI was moderately correlated to PSG-AHI, but WP-AHI was significantly lower than PSG-AHI (28.4 ± 19.2 versus 53.6 ± 30.2 events/h, P < .0001). For the lower PWV group, there was a significant correlation and good agreement between the WP-AHI and PSG-AHI, but as the PWV increased, there was low correlation between the WP-AHI and PSG-AHI.

CONCLUSIONS

Arterial stiffness may affect the respiratory variables measured by WatchPAT in patients with OSA.

COMMENTARY

A commentary on this article appears in this issue on page 301.

Obstructive sleep apnea and postoperative complications among patients undergoing gynecologic oncology surgery

OBJECTIVE

To investigate the prevalence of obstructive sleep apnea (OSA), physiological or risk factors associated with OSA, and OSA-associated postoperative complications among patients undergoing gynecologic oncology surgery.

METHODS

A prospective observational study enrolled gynecologic oncology patients undergoing abdominal surgery at a center in the UK between August 2009 and January 2013. All patients underwent perioperative sleep oximetry for the diagnosis of OSA. Data assessed included the body mass index, the STOP-Bang score, the Epworth Sleepiness Scale score, the apnea-hypopnea index, and postoperative complications. Associations were determined between preoperative OSA and postoperative OSA, postoperative complications, and risk factors such as body mass index, age, STOP-Bang score, and Epworth score.

RESULTS

Among 160 participants, 72 (45.0%) were obese and 80 (50.0%) had OSA. Obesity, older age (more than 65 years), and a neck circumference of 40 cm or more were significantly associated with OSA. Overall, 58 (36.3%) patients had postoperative complications; 21 (13.1%) had surgical complications and 37 (23.1%) had medical complications. Complications were not associated with OSA (P=0.612). Four (2.5%) patients died; mortality was not associated with OSA (P=0.810).

CONCLUSION

OSA is common among gynecologic oncology patients. Portable sleep oximetry identifies gynecology patients who have OSA or require postoperative critical care. Obesity is associated with OSA, but OSA is not associated with postoperative complications in gynecologic oncology patients.

Effective Apnea-Hypopnea Index ("Effective AHI"): A New Measure of Effectiveness for Positive Airway Pressure Therapy

STUDY OBJECTIVES

To assess a new measure of positive airway pressure (PAP) effectiveness, the Effective AHI, which accounts for sleep disordered breathing events during the time PAP is (PAP On) and is not (PAP Off) being used. A secondary aim was to test the accuracy of the Watch-PAT 200 (WP) portable monitor for measurement of the Effective AHI.

METHODS

A prospective two-center cohort study design was used to evaluate patients who had been prescribed PAP therapy for ≥ 2 months. The primary outcome measure was the Effective AHI as determined by an in-laboratory polysomnogram (PSG) where patients used their PAP machine as they did at home, and concomitantly wore the WP. The Effective AHI equals the sum of apneas and hypopneas with PAP On and PAP Off divided by hours of total sleep time.

RESULTS

Twenty-eight adult patients (75% men, age 51.4 ± 10.8 years [mean ± SD]) comprised the study sample. The mean Effective AHI of 18.3, was significantly lower than the mean Diagnostic AHI of 67.9 (P < 0.0001). All patients using PAP ≥ 6 h had an Effective AHI < 5. For patients using PAP < 6 h, Effective AHI scores < 5 only occurred in patients who slept in a non-supine position during PAP Off time; leaving 63.6% of patients with residual moderate-to-severe OSA. There was a high correlation between the PSG and WP for the Effective AHI (r = 0.871).

CONCLUSIONS

Significant disease burden, as objectively measured by the Effective AHI, may still exist in many patients with severe OSA in whom PAP therapy is not utilized for the entire sleep period. The WP is a reasonably accurate device to measure the Effective AHI.

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-based diagnosis of obstructive sleep apnea in an urban population

STUDY OBJECTIVES

Home-based diagnosis of obstructive sleep apnea (OSA) with portable monitoring (PM) is increasingly utilized, but remains understudied in underserved and minority populations. We tested the feasibility of home PM in an urban population at risk for OSA compared to in-laboratory polysomnography (PSG) and examined patient preference with respect to home PM versus PSG.

METHODS

Randomized crossover study of home PM (WatchPAT200) and in-laboratory simultaneous PSG and PM in 75 urban African Americans with high pre-test probability of OSA, identified with the Berlin questionnaire.

RESULTS

Fifty-seven of 75 participants were women, average age 45 ± 11 years (mean ± SD), 35% with ≤ high school education, and 76% with annual household income < $50,000. Technical failure rates were 5.3% for home vs. 3.1% for in-laboratory PM. There was good agreement between apnea hypopnea index on PSG; AHIPSG and AHI on home PM (mean ± 2 SD of the differences = 0.64 ± 46.5 and intraclass correlation coefficient; ICC = 0.73). The areas under the curve for the receiver-operator characteristic curves for home PM were 0.90 for AHIPSG ≥ 5, 0.95 for AHIPSG ≥ 10, and 0.92 for AHIPSG ≥ 15. 62/75 (82%) participants preferred home over in-laboratory testing.

CONCLUSIONS

Home PM for diagnosis of OSA in a high risk urban population is feasible, accurate, and preferred by patients. As home PM may improve access to care, the cost-effectiveness of this diagnostic strategy for OSA should be examined in underserved urban and rural populations.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov, identifier: NCT01997723.

The Effect of the Transition to Home Monitoring for the Diagnosis of OSAS on Test Availability, Waiting Time, Patients' Satisfaction, and Outcome in a Large Health Provider System

During 2009, the Haifa district of Clalit Health Services (CHS) has switched from in-lab polysomnography (PSG) to home studies for the diagnosis of obstructive sleep apnea (OSA). We assessed the effects of this change on accessibility, waiting time, satisfaction, costs, and CPAP purchase by the patients. Data regarding sleep studies, CPAP purchase, and waiting times were collected retrospectively from the computerized database of CHS. Patients' satisfaction was assessed utilizing a telephone questionnaire introduced to a randomized small sample of 70 patients. Comparisons were made between 2007 and 2008 (in-lab PSGs) and 2010 and 2011 (when most studies were ambulatory). Of about 650000 insured individuals in the Haifa district of CHS, 1471 sleep studies were performed during 2007-2008 compared to 2794 tests during 2010-2011. The average waiting time was 9.9 weeks in 2007-2008 compared to 1.1 weeks in 2010-2011 (P < 0.05). 597 CPAPs were purchased in 2007-2008 compared to 831 in 2010-2011. The overall patients' satisfaction was similar, but discomfort tended to be higher in the in-laboratory group (4.1 vs 2.7 in a scale of 0-10; P = 0.11). Switching to ambulatory diagnosis improved the test accessibility and reduced the waiting times. Patients' satisfaction remained similarly high. The total direct cost of OSA management was reduced.

Reliability of the Watch-PAT 200 in detecting sleep apnea in highway bus drivers

OBJECTIVE

To predict the validity of Watch-PAT (WP) device for sleep disordered breathing (SDB) among highway bus drivers.

METHOD

A total number of 90 highway bus drivers have undergone polysomnography (PSG) and Watch-PAT test simultaneously. Routine blood tests and the routine ear-nose-throat (ENT) exams have been done as well.

RESULTS

The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 89.1%, 76.9%, 82% and 85.7% for RDI > 15, respectively. WRDI, WODI, W < 90% duration and Wmean SaO2 results were well correlated with the PSG results. In the sensitivity and specificity analysis, when diagnosis of sleep apnea was defined for different cut-off values of RDI of 5, 10 and 15, AUC (95%CI) were found as 0.84 (0.74-0.93), 0.87 (95%CI: 0.79-0.94) and 0.91 (95%CI: 0.85-0.97), respectively. There were no statistically significant differences between Stage1+2/Wlight and Stage REM/WREM. The percentage of Stage 3 sleep had difference significant statistically from the percentage of Wdeep. Total sleep times in PSG and WP showed no statistically important difference. Total NREM duration and total WNREM duration had no difference either.

CONCLUSION

Watch-PAT device is helpful in detecting SDB with RDI > 15 in highway bus drivers, especially in drivers older than 45 years, but has limited value in drivers younger than 45 years old who have less risk for OSA. Therefore, WP can be used in the former group when PSG is not easily available.

Screening for sleep disordered breathing among applicants for a professional driver's license

OBJECTIVES

Individuals with sleep disordered breathing (SDB) are at high risk for falling asleep while driving. The aim of this study was to identify variables that would predict SDB among healthy young applicants for a professional driver's license.

METHOD

A total of 301 applicants for a driver's license completed self-administered questionnaires. Sleep was recorded for one night with the Watch peripheral arterial tone-100. To identify possible predictors of SDB (Respiratory Disturbance Index >15), we employed new statistical methods.

RESULTS

The following items were identified as significant predictors of SDB: body mass index, age, Mini Sleep Questionnaire, smoking, father snoring, afternoon nap-taking, and falling asleep while traveling as a passenger. Moderate or severe SDB was prevalent in at least 25% of the applicants.

CONCLUSION

New statistical methods revealed that a combination of questions related to sleep habits, complaints, and demographic data predicted most of the clinically significant SDB.

A critical review of peripheral arterial tone and pulse transit time as indirect diagnostic methods for detecting sleep disordered breathing and characterizing sleep structure

PURPOSE OF REVIEW

Sympathetic activity varies continuously across sleep stages. During rapid eye movement sleep, sympathetic tone increases substantially but is highly variable. Microarousals are associated with momentary bursts of sympathetic activity. Abnormal respiratory events progressively elevate sympathetic activity in proportion to the severity of oxyhemoglobin desaturation. These phenomena imply that cardiovascular markers of sympathetic activity such as peripheral arterial tone (PAT) and pulse transit time could be indirect tools for diagnosing sleep disordered breathing and characterizing sleep structure and fragmentation.

RECENT FINDINGS

Measurement of variations in PAT coupled with pulse rate accelerations and desaturations in oximetry can be used to diagnose sleep apnea. Good agreement between both manually and automatically analyzed PAT recordings and polysomnography has been demonstrated during in-laboratory or at-home studies. Numerous validation studies against esophageal pressure have demonstrated that pulse transit time is the best noninvasive method for measurement of respiratory effort. Pulse transit time and PAT are sensitive techniques for arousal recognition, particularly in children and infants. There are specific sleep stage-dependent PAT patterns that allow for the recognition of rapid eye movement sleep and, in the case of nonrapid eye movement sleep, the separation of lighter stages from deeper, slow wave sleep. Elevated nocturnal sympathetic activity as documented by PAT attenuations is linked with chronically elevated blood pressure in humans.

SUMMARY

Cardiovascular markers of autonomic control during sleep permit not only the diagnosis of obstructive sleep apnea and estimation of sleep structure but are also linked with the prevalence of daytime hypertension.

Surgical reconstruction of the upper airway for obstructive sleep apnea

Positive airway pressure can be effective for OSA treatment but is not effectively used by many patients. Surgical reconstruction of the airway is appropriate for patients who are not otherwise effectively treated or as first-line treatment for patients with focal airway lesions. For surgical planning, examination schemes of the awake patient, as well as sleep endoscopy may be used. Nasal surgery may facilitate treatment using positive airway pressure or oral appliances or to improve quality of life. Pharyngoplasty and tongue base techniques for therapeutic upper airway reconstruction may be performed staged or simultaneously. Current and future approaches are described.

Watch peripheral arterial tonometry in the diagnosis of obstructive sleep apnea: influence of aging

OBJECTIVES/HYPOTHESIS

To investigate the consequences of aging and associated peripheral vascular tone impairment on peripheral arterial tonometry (Watch PAT)-based sleep and respiratory disturbance analysis in obstructive sleep apnea (OSA) diagnosis.

STUDY DESIGN

Prospective, nonrandomized, clinical trial.

METHODS

A total of 56 subjects with age ranges of 20 to 35 years (group I, n = 27) and 50 to 65 years (group II, n = 29) referred to the sleep laboratory for overnight polysomnography (PSG) with suspected OSA were enrolled. All patients underwent simultaneous overnight PSG and Watch PAT monitoring. The data derived from PSG and Watch PAT records, including apnea-hypopnea index (AHI), rapid eye movement (REM) AHI, non-rapid eye movement (NREM) AHI, oxygen desaturation index (ODI), mean O(2) saturation (mean O(2) sat), minimum O(2) saturation (min O(2) sat), sleep duration, and the percentages of NREM sleep stages 1-2 and 3 and of REM sleep were used for comparisons. The calculated ΔPSG-Watch PAT of the two groups were compared statistically. The correlations between the PSG-Watch PAT measurements in each group were assessed.

RESULTS

The comparison of AHI, REM AHI, NREM AHI, ODI, mean O(2) sat, min O(2) sat, NREM sleep stage 1-2, and REM sleep ΔPSG-Watch PAT between the two groups did not reveal statistical significance. The difference between the two groups in terms of ΔPSG-Watch PAT of sleep duration and sleep stage 3 was statistically significant.

CONCLUSIONS

In addition to the good agreement confirmed between PSG and Watch PAT data in each group, aging did not negatively impact Watch PAT recorded data in terms of included parameters, except the difference in ΔPSG-Watch PAT of sleep stage 3, which may be attributable to aging and impaired vascular tone.

Obstructive sleep apnea devices for out-of-center (OOC) testing: technology evaluation

Guidance is needed to help clinicians decide which out-of-center (OOC) testing devices are appropriate for diagnosing obstructive sleep apnea (OSA). A new classification system that details the type of signals measured by these devices is presented. This proposed system categorizes OOC devices based on measurements of Sleep, Cardiovascular, Oximetry, Position, Effort, and Respiratory (SCOPER) parameters.Criteria for evaluating the devices are also presented, which were generated from chosen pre-test and post-test probabilities. These criteria state that in patients with a high pretest probability of having OSA, the OOC testing device has a positive likelihood ratio (LR+) of 5 or greater coinciding with an in-lab-polysomnography (PSG)-generated apnea hypopnea index (AHI) ≥ 5, and an adequate sensitivity (at least 0.825).Since oximetry is a mandatory signal for scoring AHI using PSG, devices that do not incorporate oximetry were excluded. English peer-reviewed literature on FDA-approved devices utilizing more than 1 signal was reviewed according to the above criteria for 6 questions. These questions specifically addressed the adequacy of different respiratory and effort sensors and combinations thereof to diagnose OSA. In summary, the literature is currently inadequate to state with confidence that a thermistor alone without any effort sensor is adequate to diagnose OSA; if a thermal sensing device is used as the only measure of respiration, 2 effort belts are required as part of the montage and piezoelectric belts are acceptable in this context; nasal pressure can be an adequate measurement of respiration with no effort measure with the caveat that this may be device specific; nasal pressure may be used in combination with either 2 piezoelectric or respiratory inductance plethysmographic (RIP) belts (but not 1 piezoelectric belt); and there is insufficient evidence to state that both nasal pressure and thermistor are required to adequately diagnose OSA. With respect to alternative devices for diagnosing OSA, the data indicate that peripheral arterial tonometry (PAT) devices are adequate for the proposed use; the device based on cardiac signals shows promise, but more study is required as it has not been tested in the home setting; for the device based on end-tidal CO(2) (ETCO(2)), it appears to be adequate for a hospital population; and for devices utilizing acoustic signals, the data are insufficient to determine whether the use of acoustic signals with other signals as a substitute for airflow is adequate to diagnose OSA.Standardized research is needed on OOC devices that report LR+ at the appropriate AHI (≥ 5) and scored according to the recommended definitions, while using appropriate research reporting and methodology to minimize bias.

Respiratory event detection by a positive airway pressure device

STUDY OBJECTIVES

Compare automatic event detection (AED) of respiratory events using a positive airway pressure (PAP) device with manual scoring of polysomnography (PSG) during PAP treatment of obstructive sleep apnea (OSA).

DESIGN

Prospective PSGs of patients using a PAP device.

SETTING

Six academic and private sleep disorders centers.

PATIENTS

A total of 148 PSGs from 115 participants with OSA (apnea-hypopnea index [AHI] ≥ 15 events/hr) were analyzed.

INTERVENTIONS

A signal generated by the PAP device identifying the AED of respiratory events based on airflow was recorded during PSG.

MEASUREMENTS AND RESULTS

The PSGs were manually scored without visualization of the AED signal and scoring of a hypopnea required a ≥ 4% oxygen desaturation. The apnea index (AI), hypopnea index (HI), and AHI by manual score and PAP AED were compared. A customized computer program compared individual events by manual scoring and AED to determine the true positive, false positive, false negative, or true negative events and found a sensitivity of 0.58 and a specificity of 0.98. The AHI, AI, and HI by the two methods were highly correlated. Bland-Altman analysis showed better agreement for AI than HI. Using a manually scored AHI of ≥ 10 events/hr to denote inadequate treatment, an AED AHI ≥ 10 events/hr had a sensitivity of 0.58 and a specificity of 0.94.

CONCLUSIONS

An AHI < 10 events/hr by PAP AED is usually associated with good treatment efficacy. Differences between manually scored and AED events were primarily due to different criteria for hypopnea detection.

Complications/adverse effects of maxillomandibular advancement for the treatment of OSA in regard to outcome

Objective: To evaluate adverse effects/postoperative complications and surgical response rate of maxillomandibular advancement for the treatment of severe obstructive sleep apnea syndrome.

Study Design: Case series with chart review.

Setting: Otolaryngology Head and Neck Surgery Department in a teaching hospital.

Subjects and Methods: A total of 59 consecutive severe sleep apnea patients underwent maxillomandibular advancement. Systemic complications were evaluated from medical charts. Functional adverse effects and cosmetic consequences were evaluated by questionnaires. The treatment outcome was assessed by polysomnography.

Results: Fifty patients were evaluated. They had a mean age of 46.4 ± 9.0 years. No serious postoperative complication was observed. The most frequent local complication was mental nerve sensory loss. Most patients reported cosmetic changes. The mean apnea-hypopnea index decreased from 65.5 ± 26.7 per hour to 14.4 ± 14.5 per hour ( P < 0.0001). Light-sleep stages were also decreased ( P < 0.0001), whereas deep-sleep stages were increased ( P < 0.001).

Conclusion: Maxillomandibular advancement can induce local adverse effects and cosmetic changes, but they seem to be considered as secondary to the patients according to the surgical outcome.

The effects of 1-year treatment with a herbst mandibular advancement splint on obstructive sleep apnea, oxidative stress, and endothelial function

BACKGROUND

Obstructive sleep apnea (OSA) is associated with endothelial dysfunction. In the current study, we assessed the effect of long-term modified Herbst mandibular advancement splint (MAS) treatment on OSA, oxidative stress markers, and on endothelial function (EF).

METHODS

A total of 16 subjects participated (11 men and 5 women; mean [+/- SD] age, 54.0 +/- 8.3 years; mean body mass index, 28.0 +/- 3.1 kg/m(2)), 12 of whom completed the 1-year evaluation. Apnea severity, levels of oxidative stress markers, and EF were assessed after 3 months and 1 year of receiving treatment. For comparison, 6 untreated patients underwent two evaluations 9 months apart, and 10 non-OSA individuals were assessed once as a reference group. The results are presented as the mean +/- SD.

RESULTS

The mean apnea-hypopnea index (AHI) decreased significantly from 29.7 +/- 18.5 events/h before treatment to 17.7 +/- 11.1 events/h after 3 months of treatment and 19.6 +/- 11.5 events/h after 1 year of treatment (p < 0.005 for both). The mean Epworth sleepiness scale score decreased significantly from 12.4 +/- 6.0 before treatment to 10.2 +/- 6.6 after 3 months of treatment and 7.8 +/- 3.8 after 1 year of treatment (p < 0.001 for both). The mean EF improved significantly from 1.77 +/- 0.4 before treatment to 2.1 +/- 0.4 after 3 months of treatment (p < 0.05) and 2.0 +/- 0.3 after 1 year of treatment (p = 0.055), which were similar to the values of the reference group. Thiobarbituric acid-reactive substance (TBARS) levels decreased from 18.8 +/- 6.2 nmol malondialdehyde (MDA)/mL before treatment to 15.8 +/- 3.9 MDA/mL after 3 months of treatment (p = 0.09) and 15.5 +/- 3.2 nmol MDA/mL after 1 year of treatment (p < 0.05). There was a correlation between the improvement in AHI and in EF or TBARS levels (r = 0.55; p = 0.05). The untreated control group remained unchanged.

CONCLUSIONS

The Herbst MAS may be a moderately effective long-term treatment for patients with OSA. EF improved to levels that were not significantly different than reference levels, even though apneic events were not completely eliminated. We think that these data are encouraging and that they justify the performance of larger randomized controlled studies.