Feasibility of unattended home polysomnography in children with sleep-disordered breathing

The Role of Telemedicine in Children with Obstructive Sleep Apnea Syndrome (OSAS): A Review of the Literature

The advent of telemedicine marked a significant turning point in the healthcare landscape, introducing a revolutionary approach to the delivery of medical care. Digital technologies easily connect health professionals and patients, overcoming geographical and temporal barriers. Telemedicine has been used for sleep disorders including obstructive sleep apnea syndrome (OSAS) since the mid-1990s. In adult patients with OSAS, telemedicine is helpful both for consultation and diagnosis, the latter obtained through remote recordings of oxygen saturation and further parameters registered with telemonitored respiratory polygraphy or polysomnography. Remote monitoring can be used to follow up the patient and verify adherence to daily treatments including continuous positive airway pressure (CPAP). In children, studies on the role of telemedicine in OSAS are scarce. This narrative review aims to describe the application of telemedicine in children with obstructive sleep apnea syndrome (OSAS), assessing its advantages and disadvantages. In patients with OSA, telemedicine is applicable at every stage of patient management, from diagnosis to treatment monitoring also in pediatric and adolescent ages. While telemedicine offers convenience and accessibility in healthcare delivery, its application in managing OSAS could be associated with some disadvantages, including limitations in physical examination, access to diagnostic tools, and education and counseling; technology barriers; and privacy concerns. The adoption of a hybrid approach, integrating both in-office and virtual appointments, could effectively meet the needs of children with OSAS. However, more studies are needed to fully assess the effectiveness and safety of telemedicine in the pediatric population.

Obstructive sleep apnea in asthmatic children: a cross-sectional study about prevalence and risk factors

OBJECTIVES

Primary objectives were to analyze the prevalence of obstructive sleep apnea in (1) boys and girls, and (2) severe asthma versus moderate and mild cases. The authors hypothesized that girls and severe asthma would have a higher prevalence of obstructive sleep apnea.

METHODS

Cross-sectional evaluation of asthmatic children attending a tertiary Pediatric Pulmonology clinic. The authors performed a history, physical examination, pulmonary function test, and home sleep apnea test.

RESULTS

The authors studied 80 consecutive patients, 7-18 years old, mean age of 11.6 years (standard deviation 2.7), 51.3% female, and 18.5% obese. Pulmonary function tests were obtained from 80 volunteers, 45% with obstruction pattern. Home sleep apnea tests were available from 76 volunteers, with a mean obstructive respiratory index of 1.8 events/h. Obstructive sleep apnea was found in 49 volunteers (61.2%). The authors did not find associations between obstructive sleep apnea and sex or asthma severity.

CONCLUSIONS

Obstructive sleep apnea was frequent among these asthmatic children. Sex and asthma severity were not risk factors. Considering the interrelationship of both diseases, it is worth keeping in mind the possibility of obstructive sleep apnea among children and teenagers with asthma.

Diagnosis of Paediatric Obstructive Sleep-Disordered Breathing beyond Polysomnography

Obstructive sleep-disordered breathing (SDB) has significant impacts on health, and therefore, a timely and accurate diagnosis is crucial for effective management and intervention. This narrative review provides an overview of the current approaches utilised in the diagnosis of SDB in children. Diagnostic methods for SDB in children involve a combination of clinical assessment, medical history evaluation, questionnaires, and objective measurements. Polysomnography (PSG) is the diagnostic gold standard. It records activity of brain and tibial and submental muscles, heart rhythm, eye movements, oximetry, oronasal airflow, abdominal and chest movements, body position. Despite its accuracy, it is a time-consuming and expensive tool. Respiratory polygraphy instead monitors cardiorespiratory function without simultaneously assessing sleep and wakefulness; it is more affordable than PSG, but few paediatric studies compare these techniques and there is optional recommendation in children. Nocturnal oximetry is a simple and accessible exam that has high predictive value only for children at high risk. The daytime nap PSG, despite the advantage of shorter duration and lower costs, is not accurate for predicting SDB. Few paediatric data support the use of home testing during sleep. Finally, laboratory biomarkers and radiological findings are potentially useful hallmarks of SDB, but further investigations are needed to standardise their use in clinical practice.

Alternatives to Polysomnography for the Diagnosis of Pediatric Obstructive Sleep Apnea

Diagnosis of obstructive sleep apnea (OSA) in children with sleep-disordered breathing (SDB) requires hospital-based, overnight level I polysomnography (PSG). Obtaining a level I PSG can be challenging for children and their caregivers due to the costs, barriers to access, and associated discomfort. Less burdensome methods that approximate pediatric PSG data are needed. The goal of this review is to evaluate and discuss alternatives for evaluating pediatric SDB. To date, wearable devices, single-channel recordings, and home-based PSG have not been validated as suitable replacements for PSG. However, they may play a role in risk stratification or as screening tools for pediatric OSA. Further studies are needed to determine if the combined use of these metrics could predict OSA.

Unattended home sleep studies for the diagnosis of obstructive sleep apnea in a population of French children

BACKGROUND

Ambulatory exams were preferred in children during the COVID-19 pandemic. Polysomnography (PSG), the gold standard for obstructive sleep apnea (OSA) diagnosis, requires several leads and sensors to be attached to the child's body. Children are more comfortable with respiratory polygraphic (RP) recording, which needs fewer sensors.

OBJECTIVE

To compare respiratory parameters obtained by home RP with those obtained by home PSG with the device installed at the child's home by a trained sleep nurse from a national health care provider.

METHODS

Data from home PSGs performed in children aged 2-19 years were retrospectively included. The obstructive apnea-hypopnea index (OAHI) was computed in PSG and then in RP after removing the sleep signals. The two indexes were compared using non-parametric paired Wilcoxon rank test, Bland-Altman analysis and sensitivity-specificity analysis.

RESULTS

44 PSGs of 44 children were included with only 34 (77%) PSGs interpretable. Median (min-max) OAHI was significantly underestimated in RP than in PSG (2.2 (0-25) vs 4.0 (0.4-28), p < 0.0001), confirmed also by the Bland-Altman diagram, the magnitude of the difference being mean ± standard deviation -1.7 ± 1.7. The sensitivity and specificity of OAHI in RP to identify an OAHI ≥2/h in PSG was 0.91 for both.

CONCLUSION

Unattended ambulatory RP performed at child's house and installed under carefully controlled conditions is a useful exam for diagnosing OSA in children with or without comorbidities. However, RP must be installed in a supervised environment and interpreted with caution as it tends to underestimate OSA severity.

Two nights of home polysomnography in healthy 7-14-year-old children - Feasibility and intraindividual variability

OBJECTIVE

Attended polysomnography (PSG) is the gold standard for childhood sleep evaluation. There is, however, only limited information regarding repeated ambulatory PSG in children. We aimed to test whether in hospital attached level 2 home PSG is feasible and reproducible in healthy children.

METHODS

We recruited healthy children aged 7-14 years to undergo two nights of full level 2 PSG. The PSG equipment was attached at the hospital on the day of the sleep test and all recordings were performed at home. Subjective sleep quality, nocturnal urine production, sleep time and number of awakenings were documented for a week in connection to the first PSG night.

RESULTS

Thirty-three children were recruited of whom 32 children (aged 11 ± 2.1 years) underwent two nights of PSG. All 64 PSGs were technically adequate for sleep evaluation. We found mean sleep efficiency of 94% and mean total sleep time of 8.4 h. Sleep stages distribution with 5.9% N1, 46.8% N2, 24.3% N3 and 22.8% REM sleep. We found poorer subjective sleep quality, more self-reported awakenings, and shorter total sleep time on nights with PSG compared to nights without PSG with no differences between PSG study nights. No differences in nocturnal urine production were found between nights with and without PSG. The comparison of PSG variables between the two PSG nights revealed no first night effect.

CONCLUSIONS

Type 2 PSG recording is feasible for sleep evaluation in children 7-14 years of age producing good data quality. We found no first night effect on PSG variables. www.

CLINICALTRIALS

gov Registration number: NCT03477812.

ERS technical standards for using type III devices (limited channel studies) in the diagnosis of sleep disordered breathing in adults and children

For more than three decades, type III devices have been used in the diagnosis of sleep disordered breathing in supervised as well as unsupervised settings. They have satisfactory positive and negative predictive values for detecting obstructive and central sleep apnoea in populations with moderately high pre-test probability of symptoms associated with these events. However, standardisation of commercially available type III devices has never been undertaken and the technical specifications can vary widely. None have been subjected to the same rigorous processes as most other diagnostic modalities in the medical field. Although type III devices do not include acquisition of electroencephalographic signals overnight, the minimum number of physical sensors required to allow for respiratory event scoring using standards outlined by the American Academy of Sleep Medicine remains debatable. This technical standard summarises data on type III studies published since 2007 from multiple perspectives in both adult and paediatric sleep practice. Most importantly, it aims to provide a framework for considering current type III device limitations in the diagnosis of sleep disordered breathing while raising research- and practice-related questions aimed at improving our use of these devices in the present and future.

Telehealth-supported level 2 pediatric home polysomnography

STUDY OBJECTIVES

The gold standard for diagnosis of pediatric obstructive sleep apnea is level 1 polysomnography (PSG). Some children are selected for unattended level 2 home sleep apnea testing (HSAT) with telehealth support, and we sought to review this home service.

METHODS

A retrospective audit was conducted from 2013 to 2020. All level 2 HSAT reports in children aged 5-18 years referred for suspected OSA were analyzed. American Academy of Sleep Medicine compliant portable PSG acquisition equipment with EEG was used. The primary outcome was the proportion of technically successful tests achieved, and of these the % with potential underestimation of diagnostic category. Secondary outcomes included sleep quality and parental acceptance by non-validated service-specific questionnaire. Data were analyzed using descriptive & inferential statistics. χ² tests were used for categorical variables.

RESULTS

There were 233 (139 male, 59.6%) patients studied between 2013 and 2020 (7 years). The mean age was 10.8 (SD 3.6) years. 67 patients (28.8%) had comorbidities. Technically successful studies were obtained in almost 90% (209/233) and failed studies occurred in just over 10% (24/233). One failed study still achieved a diagnosis. There was no significant difference between failed studies set up by HITH nurses compared with Sleep scientists (p=0.2). Overall, an accurate diagnosis was made in 80% (167/209) of patients, with potential for under-estimation in 20% (42/209). Six hours or more of sleep was obtained in 89.5%. Parental questionnaires revealed 89.3% perceived high-level care, 91% perceived increased convenience and 76% good/excellent telehealth support.

CONCLUSIONS

Telehealth-supported pediatric HSAT achieves technical success in almost 90% of patients investigated for OSA, with 89.5% achieving ≥6 hours sleep duration, and excellent family acceptability.

Trends in Diagnosing Obstructive Sleep Apnea in Pediatrics

Obstructive sleep apnea in children has been linked with behavioral and neurocognitive problems, impaired growth, cardiovascular morbidity, and metabolic consequences. Diagnosing children at a young age can potentially prevent significant morbidity associated with OSA. Despite the importance of taking a comprehensive sleep history and performing thorough physical examination to screen for signs and symptoms of OSA, these findings alone are inadequate for definitively diagnosing OSA. In-laboratory polysomnography (PSG) remains the gold standard of diagnosing pediatric OSA. However, there are limitations related to the attended in-lab polysomnography, such as limited access to a sleep center, the specialized training involved in studying children, the laborious nature of the test and social/economic barriers, which can delay diagnosis and treatment. There has been increasing research about utilizing alternative methods of diagnosis of OSA in children including home sleep testing, especially with the emergence of wearable technology. In this article, we aim to look at the presentation, physical exam, screening questionnaires and current different modalities used to aid in the diagnosis of OSA in children.

Pulse transit time as a diagnostic test for OSA in children with Down syndrome

STUDY OBJECTIVES

Children with Down syndrome (DS) are at risk of obstructive sleep apnea (OSA), but the access to sleep lab polysomnography (PSG) is limited. Simplified techniques are needed, such as polygraphy coupled with pulse transit time (PTT-PG) that detects respiratory events and the total autonomic arousals index (PTTAI). Our objective was to assess the ability of PTT-PG compared with PSG to diagnose OSA in children with DS.

METHODS

In this prospective multicenter study, patients with DS underwent a full-night PSG coupled with PTT. Sleep questionnaires (Sleep Disturbance Scale for Children and Pediatric Sleep Questionnaire) were filled by parents. PSG and PTT-PG results were compared to test their sensibility and specificity to diagnose OSA.

RESULTS

A total of 53 patients with DS were included; their median age was 9.3 years. An obstructive apnea-hypopnea index (OAHI) by PSG > 1 event/h was found in 36 (68%) patients, OAHI was > 1 and < 5 events/h in 18 patients (34%), ≥ 5 and < 10 events/h in 11 patients (21%), and ≥ 10 events/h in 7 patients (13%). OAHI was larger on PSG than on PTT-PG (P = .0005). For OSA diagnosis, the sensitivity was excellent for OAHI by PTT-PG if the added total PTTAI was > 1 event/h (1.0) and the specificity was high for the Pediatric Sleep Questionnaire (0.88) and OAHI > 1 event/h on PTT-PG (1.0).

CONCLUSIONS

More than two-thirds of children with DS referred for screening by a genetics specialist had OSA diagnosed by PSG. With its excellent sensitivity and specificity, PTT-PG could be a good and simplified alternative to PSG to diagnose OSA in children with DS.

CITATION

Ioan I, Weick D, Sevin F, et al. Pulse transit time as a diagnostic test for OSA in children with Down syndrome. J Clin Sleep Med. 2022;18(1):119-128.

Obstructive sleep apnea in children with Down syndrome: is it possible to predict severe apnea?

The objectives are to explore the demographic and polysomnographic features of children with Down syndrome and to determine the predictive factors associated with severe sleep apnea. A total of 81 children with Down syndrome referred for full-night polysomnography were analyzed. In addition, parental interviews were performed for each child. Data were available for 81 children, with a mean age of 4.8 years. Severe obstructive sleep apnea was determined in 53.1%. Age, sex, exposure to second-hand smoke, clinical findings, anthropometric features, and the presence of comorbidities were not predictors of severe obstructive sleep apnea. Children who were exposed to second-hand smoke had more sleep-related symptoms. Even in children without symptoms, the prevalence of severe obstructive sleep apnea was 40%. Moreover, 86% of parents had no previous information regarding possible sleep breathing disorders in their children. Clinically significant central apnea was present in 10 patients (12.3%).Conclusion: Our results demonstrate that severe obstructive sleep apnea is common in children with Down syndrome, even in children without a history of symptoms of sleep apnea. It is not possible to predict patients with severe apnea; thus, screening of children with Down syndrome beginning from young ages is very important. Central apneas could be a part of the spectrum of sleep abnormalities in Down syndrome.

Sleep Measurement in Children-Are We on the Right Track?

Sleep plays a critical role in the development of healthy children. Detecting sleep and sleep disorders and the effectiveness of interventions for improving sleep in children require valid sleep measures. Assessment of sleep in children, in particular infants and young children, can be a quite challenging task. Many subjective and objective methods are available to evaluate various aspects of sleep in childhood, each with their strengths and limitations. None can, however, replace the importance of thorough clinical interview with detailed history and clinical examination by a sleep specialist.

[Diagnostic criteria for obstructive sleep apnea syndrome in adolescent]

The obstructive sleep apnoea syndrome (OSAS) affects 1-4% of adolescents. It represents a transitional stage between paediatric and adult OSA and is characterized by specific symptoms. BACKGROUND: The persistence of childhood OSAS during adolescence is not frequent. Risk factors are male sex, obesity and a history of tonsillectomy or adenoidectomy. Symptoms may be misleading such as tiredness and depressive disorders. In adolescence, untreated OSAS may result in neuro-behavioural and cognitive deficits, systemic inflammation, cardiovascular and metabolic disorders. The French Society of Research and Sleep Medicine organized a meeting on OSAS in adolescents. A multidisciplinary group of specialists (pulmonologists, pediatricians, ENT and maxillo-facial surgeons, dentofacial orthopedists/orthodontists, myofunctional therapists and sleep specialists) exchanged their experience, discussed publications and drew up a consensus document on the diagnosis and polysomnographic criteria for OSAS in adolescents. They proposed a practical diagnostic guideline and follow-up for these adolescents. OUTLOOK AND CONCLUSION: A good knowledge of the particularities of this pathology by the physician will lead to an early diagnosis, propose adapted multifactorial treatments and avoid the deleterious consequences of this pathology at adult age.

Alternatives to surgery in children with mild OSA

Precision medicine requires coordinated and integrated evidence-based combinatorial approaches so that diagnosis and treatment can be tailored to the individual patient. In this context, the treatment approach to mild obstructive sleep apnea (OSA) is fraught with substantial debate as to what is mild OSA, and as to what constitutes appropriate treatment. As such, it is necessary to first establish a proposed consensus of what criteria need to be employed to reach the diagnosis of mild OSA, and then examine the circumstances under which treatment is indicated, and if so, whether and when anti-inflammatory therapy (AIT), rapid maxillary expansion (RME), and/or myofunctional therapy (MFT) may be indicated.

Feasibility of conducting type III home sleep apnoea test in children

OBJECTIVES

To test the feasibility of conducting unattended paediatric type III HSAT and to identify issues for improvements to optimize signal quality.

MATERIAL AND METHODS

Parents were instructed in setting up the unattended HSAT and reported their experiences. Signal quality and causes of signal failure of recordings were assessed.

RESULTS

Forty children were included. Mean age was 5.2 years. Predefined success criteria were met in 53% of recordings. Main causes of signal failure were nasal cannula, pulse-oximetry and battery failure. Sensor fixation techniques were developed and implemented during the study and hence signal quality improved. Seventeen (94%) parents reported HSAT to be either easy or medium hard to use.Conclusions and significance: Unattended paediatric type III HSAT can be conducted at home with acceptable signal quality. Signal quality improved considerably using simple sensor fixation techniques.

Quality of poly(somno)graphy recordings in children

The aim of the study was to assess the scorability of the signals of four poly(somno)graphy devices and transcutaneous carbon dioxide tracings (PtcCO₂ ) of one device in children. The presence (0%, < 25%, 25%-50%, 50%-75%, 75%-99%, 100% of recording time) and quality (bad, average, good) of the signal of each sensor were analysed. During a 5-month period, 364 poly(somno)graphies were performed in 12 different hospital units. Forty-one children had poor/bad cooperation, and 13 severe behaviour disorders. Seventy-one and 293 poly(somno)graphies were performed in children aged ≤ 2 and > 2 years, respectively; nine poly(somno)graphies failed. For the four poly(somno)graphy devices, the signal was present during 99% of recording time for the electroencephalogram, 99% for thoracic belt, 97% for abdominal belt, 97% for body position, 95% for the microphone, 92% for pulse oximetry, 87% for tracheal sound, 71% for oronasal thermistor, 52% (41% for ≤ 2 years, 55% for > 2 years old) for nasal pressure and 86% for PtcCO₂ . The signal was of good quality in 98% of poly(somno)graphies for body position, 96% for microphone, 96% for thoracic belt, 95% for pulse oximetry, 91% for abdominal belt, 91% for tracheal sound, 82% for oronasal thermistor, 78% for electroencephalogram, 73% for nasal pressure and 46% of PtcCO₂ recordings. The scorability was comparable between devices. Nasal pressure and oronasal thermistor had the lowest scorability, especially in children aged ≤ 2 years. This underlines the necessity of the development or improvement of alternative, ideally face-free, sensors, or miniaturized devices adapted for infants and children.

Sleep diary- and actigraphy-derived sleep parameters of 8-hour fast-rotating shift work nurses: A prospective descriptive study

BACKGROUND

Given the harmful effects of night shifts and rotating schedules on nurses' sleep and work performance, shift nurses' sleep patterns have been a research concern. Actigraphy involves acquisition of data using a movement sensor worn continuously on the nondominant wrist, typically for a week or more. Although actigraphy provides objective and accurate sleep data, sleep diaries have been a practical alternative. However, there is a lack of research on the agreement and consistency between the two methods of measuring sleep for shift work nurses. In addition, differences in sleep patterns by shift types among 8-hour fast-rotating shift work nurses has not yet been examined.

OBJECTIVES

To evaluate the agreement between the sleep diary and actigraphy methods for sleep assessment, and to compare sleep parameters of 8-hour fast-rotating shift work nurses according to shift type.

DESIGN

Descriptive and prospective study design.

SETTINGS

Two tertiary hospitals in Seoul, South Korea.

PARTICIPANTS

A total of 94 shift work nurses who wore actigraphy along with completing a sleep diary.

METHODS

Subjective and objective sleep parameters were recorded during a two-week period in a sleep diary and actigraphy, respectively. Bland-Altman plots and intraclass correlation coefficients were used to analyze the agreement between the two methods. Sleep parameters according to shift type were compared using the Kruskal-Wallis and Mann-Whitney U tests.

RESULTS

Good agreement was observed between the sleep diary and the actigraphy data for total sleep time (intraclass correlation coefficients = 0.765 or 0.858) and variability in sleep time (intraclass correlation coefficients = 0.838). When compared to the actigraphy data, diary-derived data were overestimated by 41-45 min for total sleep time and 0.4% for variability in sleep time. There was a difference of 2-3 h of sleep quantity by shift type: 5.3-5.8 h for day shifts and 7.1-8.4 h for night shifts.

CONCLUSIONS

A sleep diary can function as an acceptable alternative to actigraphy for measuring shift work nurses' sleep patterns, specifically total sleep time and variability in sleep time. Given the high variability in sleep among shift work nurses, both personal and organizational efforts are required. Nurses should monitor their sleep quantity and develop their own regular sleep schedules to fit their work schedules. Hospitals should establish healthy schedules for nurses to guarantee sufficient sleep hours before work. Future research on shift work nurses' sleep should examine fluctuations in sleep duration.

Feasibility of parent-attended ambulatory polysomnography in children with suspected obstructive sleep apnea

STUDY OBJECTIVES

Due to a limited number of pediatric sleep centers, the aim was to test the feasibility of ambulatory polysomnography (PSG-home) in a group of French children suspected of OSA.

METHODS

Children undergoing one-night PSG-home, with the device installed at the pediatric sleep physician's office, were prospectively included. General failure was considered when PSG-home recording captured < 5 h of artifact-free sleep or when ≥ 1 channel (nasal flow, thoraco-abdominal belts, oximetry) presented artifacts > 75% of the recording time. No-OSA was defined as an obstructive apnea-hypopnia index (OAHI) < 1 event/h and respiratory-related arousals index (RAI) < 1 event/h. OSA was defined as upper airways resistance syndrome (UARS) with OAHI < 1 event/h with RAI ≥ 1 event/h, or mild OSA (OAHI ≥ 1 event/h-5 events/h), moderate OSA (OAHI ≥ 5 events/h-10 events/h), or severe OSA (OAHI ≥ 10 events/h). Parents completed a severity hierarchy score questionnaire, Conners Parent Rating Scale, and an adapted Epworth Sleepiness Scale.

RESULTS

Fifty-seven children aged 3 through 16 years were included. PSG-home was technically acceptable in 46 (81%). Failure due to nasal cannula was observed in 11% (n = 6), oximetry in 7% (n = 4), and both in 2% (n = 1) of cases. No difference in feasibility was found according to age, sex, OSA severity, or comorbidities. There were 14 (25%) children categorized as no-OSA, 43 (75%) as OSA, 4 (7%) as UARS, 26 (46%) as mild, 6 (10%) as moderate, and 7 (12%) as severe OSA. Neither questionnaires nor clinical and physical examination predicted OSA diagnosis.

CONCLUSIONS

When equipment is installed at the professional's office and a parent monitors the child, PSG-home is feasible and technically acceptable in children aged 3 through 16 years old. The short delay and feasibility provided by PSG-home could improve the management of children suspected of OSA.

Home Respiratory Polygraphy is Useful in the Diagnosis of Childhood Obstructive Sleep Apnea Syndrome

The utility of home respiratory polygraphy (HRP) was assessed as an alternative to polysomnography (PSG) in the diagnosis of childhood obstructive sleep apnea syndrome (OSAS). PSG was indicated only in patients with concomitant disease or where HRP results were questionable. The follow-up period was 1 year. We recorded clinical and anthropometric data, physical examination findings, respiratory variables, severity level and choice of therapy. We assessed 121 children, 70 boys and 51 girls, with mean age 7 ± 4 years, mean body mass index (BMI) 19 ± 5 kg/m², and mean BMI percentile 62 ± 38%. We included 104 HRP and 24 PSG recordings. Of the latter, 7 were preceded by HRP (false negatives) and 17 were indicated as the first-choice method owing to concomitant disease. Of the initial HRP recordings, 93% were technically valid. All technically valid HRPs and 96% of PSGs resulted in a diagnosis of OSAS (apnea-hypopnea index 9.5 ± 9.1/h). Thirty-three percent of cases were moderate and 22% severe. Apnea-hypopnea index showed no correlation with BMI or BMI percentile. Adenotonsillectomy was indicated in 93 patients (77%), conservative treatment in 17 (14%), and conservative treatment combined with CPAP/BiPAP in 11 (9%). There were no significant differences between children diagnosed by HRP and by PSG in terms of treatment choice. The prevalence of OSAS in our sample was 96.7%. In conclusion, when the probability of OSAS is high, HRP is usually sufficient for diagnosing the syndrome and establishing therapy in children. PSG is advisable in complex or questionable cases.

STOP-Bang questionnaire should be used in all adults with Down Syndrome to screen for moderate to severe obstructive sleep apnea

STUDY OBJECTIVES

To determine the prevalence of obstructive sleep apnea (OSA) in adults with Down syndrome (DS), to investigate factors related to OSA severity and to identify which sleep questionnaire is the most appropriate for the screening of OSA in this population.

METHODS

Cross-sectional study that consecutively included 60 adults with DS. All patients underwent type III polysomnography and clinical and laboratory data were collected; sleep assessment questionnaires were applied. Multiple linear regression models evaluated the associations between OSA severity (measured by the respiratory event index-REI) and clinical and laboratory data and sleep questionnaires (Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, BERLIN and STOP-Bang questionnaires).

RESULTS

Results show that 60 (100%) adults with DS had OSA, with moderate-severe OSA identified in 49 (81.6%). At the multivariate linear regression, REI significantly correlated with hematocrit levels, BMI and STOP-Bang questionnaire (SBQ) results (P <0.001). The positive STOP-Bang ≥3 points) showed 100% of sensitivity (95%CI: 92.75-100%), 45.45% of specificity (95%CI: 16.75-76.62), positive predictive value of 89.09% (95%CI: 82.64-93.34%), negative predictive value of 100%, accuracy of 90% (95%CI: 79.49-96.24%) and OR of 24.29.

CONCLUSIONS

Adults with DS have a very high prevalence of OSA. Hematocrit levels, BMI and SBQ showed a strong correlation with OSA severity. The SBQ performed well in identifying moderate to severe OSA in this population. Considered together, these results point to the need to perform OSA screening in all adults with DS, and STOP-Bang may play a role in this screening.

Tracheal sounds for the scoring of sleep respiratory events in children

STUDY OBJECTIVES

Oronasal thermistor and nasal cannula are recommended for the scoring of respiratory events (RE) but these sensors are poorly tolerated in children. The aim of the study was to evaluate tracheal sounds (TS) and suprasternal pressure (SSP) for the scoring of RE during sleep in children.

METHODS

We compared the detection and characterization of RE by AASM-recommended sensors ("AASM" scoring), with the detection and characterization of RE by the combination of TS and SSP with respiratory inductance plethysmography-sum (TS-RIP scoring), and TS and SSP only (TS scoring).

RESULTS

The recordings of 17 patients were analyzed. The TS, SSP, and RIP flow signals were present during 95%, 95%, and 99% of the validated recording time, respectively, as compared to 79% and 86% for nasal cannula and oronasal thermistor. A total of 1,456 RE were scored with the "AASM" scoring, 1,335 with the TS-RIP scoring, and 1,311 with the TS scoring. Sensitivity for apnea and hypopnea detection was 88% and 84% for the TS-RIP scoring, and 86% and 77% for the TS scoring. For apnea characterization, the TS-RIP scoring sensitivities and specificities were 97% and 100%, 76% and 98%, and 95% and 97%, for obstructive, mixed, and central apnea, respectively. For the TS scoring, they were 95% and 100%, 95% and 97%, and 91% and 97%, respectively.

CONCLUSIONS

TS and SSP + RIP-sum has a good sensitivity and specificity for the detection and characterization of apnea and hypopnea in children. TS and SSP alone have good sensitivity and specificity for apnea detection and characterization but lower sensitivity for hypopnea detection.

Successful home respiratory polygraphy to investigate sleep-disordered breathing in children

OBJECTIVE

Sleep-disordered breathing (SDB) in children is common. Interest in sleep tests, such as polygraphy (PG), which can be performed in a non-attended setting, are gaining is increasing. PG has, however, been little studied in children with co-morbidities other than obstructive sleep apnea (OSA), and in particular, if performed in a non-attended setting. We report on the feasibility and interpretability of implementing PGs at home versus in hospital.

METHODS

PGs were analyzed according to the setting (hospital or home) and sequence (initial or subsequent) in which they were performed. Non-interpretability was defined as absent or unreliable oxygen saturation by pulse oximetry (SpO₂), or airflow and respiratory inductance plethysmography flow trace signals during the time analyzed.

RESULTS

We retrospectively analyzed 400 PGs; 332/400 were initial PGs. Indications were: suspected OSA (65%), obesity (13%), craniofacial malformations (5%), neuromuscular disease (4%), and other (13%) which included prematurity. 16% were recorded in hospitals and 84% at home. The mean age was 5.7 ± 5.8 years and 7.3 ± 4.5 years for the hospital and home groups, respectively. Interpretability was similar in both settings (87%). In the 68 subsequent PGs, interpretability was 84% when performed for follow-up and 96% when repeated for non-interpretability. Non-interpretability was predominantly due to a failure of the SpO₂ channel.

CONCLUSIONS

PG performed at home is both feasible and interpretable for a variety of indications. Non-interpretability was not predictable in association with the setting, anthropometric data, or indication, independently of the sequence (initial or subsequent PG) in which the parameters were analyzed.

[Sleep-related breathing disorders in children and teenagers: diagnosis, consequences and comorbidities]

Obstructive sleep apnoea syndrome (OSAS) is a frequent sleep-related breathing disorder in children with a prevalence of approximately 3% between the ages of 3 and 8. Its origin is multifactorial (hypertrophy of pharyngeal soft tissues, narrowing of the bone airways, damage to the neuromuscular tone). The symptoms and clinical signs to look for during the day and at night are directly related to upper airway (UA) obstruction or poor sleep quality. After a complete anamnestic and clinical evaluation, including nasofibroscopy, the ENT specialist will refer to an adeno-amygdalectomy or night recording by polysomnography or polygraph to confirm the diagnosis in the child. Among adolescents, the prevalence of OSAS is reported to be between 0.5 and 6%. The main risk factors are obesity, male sex and a history of tonsillectomy. In addition to the classic symptoms of childhood OSAS, this syndrome may, in adolescents, manifest itself as a misleading semiology of dyssomnia, excessive daytime sleepiness and/or mood disorders. Differential diagnoses with risk behaviours, phase delay or narcolepsy should be systematically discussed. It is essential to record breathing during sleep. Even if the obstructive apnea/hypopnea index is low, it must be considered. In both children and adolescents, multidisciplinary management (ENT, orthodontist, maxillofacial physiotherapist, pulmonologist) should be early in order to avoid neurocognitive, behavioural, cardiovascular and metabolic complications. Maxillofacial surgery can be discussed from the age of 15. It is important not to forget to pay attention to the rules of healthy living and sleep as well as the management of obesity.

Are home sleep studies useful in diagnosing obstructive sleep apnea in children with down syndrome?

INTRODUCTION AND AIM

Obstructive sleep apnea syndrome (OSAS) is frequent in children with Down syndrome (DS) and polysomnography (PSG) is recommended for all children with DS. However PSG is not always available and alternative diagnostic methods are needed. The aim of the study was to evaluate the feasibility and validity of home polygraphy (HPG) in children with DS.

METHODS

A national DS association was contacted and children aged 6 to 18 years who accepted to participate were recruited. Otorhinolaryngologic evaluation, in-lab PSG and HPG were performed. OSAS was diagnosed by PSG with an apnea-hypopnea index (AHI) more than or equal to  1. OSAS severity was classified as moderate-to-severe if AHI was more than or equal to  5. Receiver operating characteristic curves were calculated for HPG using PSG as the gold standard.

RESULTS

Nineteen children (12 girls) completed the study. Median age was 11.3 years. Demographic and clinical characteristics were similar in children with and without OSAS. Eighty-nine percent of HPG studies were technically acceptable at the initial night and the success rate was 100% when two failed studies were repeated. PSG revealed OSAS in six (32%) children, two had mild and four had moderate-to-severe OSAS. All four patients with moderate-to-severe OSAS diagnosed with PSG have been diagnosed with the same severity on HPG. HPG had 100% sensitivity and 83% specificity when AHI ≥  3 was set as diagnostic criteria.

CONCLUSION

HPG is a feasible and reliable test of OSAS in children with DS and may be useful in diagnosis and treatment of patients with moderate-to-severe OSAS in this patient group.

The Feasibility and Utility of Level III Portable Sleep Studies in the Pediatric Inpatient Setting

STUDY OBJECTIVES

Sleep-disordered breathing (SDB) may significantly impact the course of medical illness in hospitalized children. Polysomnography (PSG) is the gold standard for establishing diagnosis of SDB, but its availability is limited. The aim of this study was to explore the feasibility and utility of level III portable sleep studies in hospitalized children with SDB.

METHODS

A retrospective study was conducted at a tertiary hospital over the preceding 2 years in hospitalized children < 18 years who had undergone a level III sleep study using the Nox T3 system. The information obtained included demographic data, comorbidities, indication for admission and sleep study, time interval between the study ordered and done, adequacy of technical data from sleep study, study diagnosis, and subsequent management interventions for SDB.

RESULTS

A total of 51 hospitalized children had these studies; 32 were female and mean age was 4.3 years. Approximately 90% of children had significant comorbidities, including neurological and craniofacial abnormalities. The majority (80%) of studies were conducted within 24 hours of the time requested and 92.1% studies had technically adequate data for analysis. Thirty-nine (76.5%) children were identified with SDB; all but one patient underwent therapy for SDB during that same hospitalization, including supplemental oxygen (48.7%), positive airway pressure therapy (23%), surgical intervention (38.2%) or caffeine (10.2%). Twelve percent of children had more than one intervention done.

CONCLUSIONS

The level III portable sleep study is readily available, sufficient to diagnose SDB, and help to provide appropriate medical and/or surgical therapies in hospitalized children with complex medical conditions.

Preschoolers with recurrent wheezing have a high prevalence of sleep disordered breathing

Objective: Sleep-disordered breathing (SDB) is highly prevalent in school children with poorly-controlled asthma. However, this association has not been assessed in preschoolers with recurrent wheeze, nor in those at risk for asthma. We hypothesized that preschoolers with asthma risk (positive asthma predictive index [API]) have a higher prevalence of SDB and higher inflammatory biomarkers (blood-hsCRP and urinary-LTE4) levels than those with negative API.Method: Children 2 to 5 years of age with recurrent wheezing were classified as positive or negative API. SDB was determined by the pediatric sleep questionnaire (PSQ) and its subscale (PSQSub6). Demographic characteristics, spirometry, blood hsCRP and urinary LTE4 were assessed.Results: We enrolled 101 preschoolers: 70 completed all measurements, 55.4% were males, mean age 4.07 ± 0.87 years, 45% overweight or obese, 70% had positive API, 87.5% had rhinitis. The prevalence of SDB measured by PSQ was 40.8% and by PSQSub6 was 29.6%. However, the proportion of SDB was similar between positive and negative API groups. The hsCRP (mean ± SD) was higher in the positive than in negative API (3.58 ± 0.58 and 1.32 ± 0.36 mg/L, p = 0.69, respectively); moreover, no differences in urinary LTE4 were found between groups. No correlation of PSQ (+) or PSQSub6 (+) with hsCRP and uLTE4 was found. However, preschoolers with positive API had significantly more post-bronchodilator percentage change in FEF25-75 than negative API (24.14 ± 28.1 vs. 4.13 ± 21.8, respectively, p = 0.01).Conclusions: In preschoolers with recurrent wheezing, we should be investigating for the coexistence of SDB, using early screening methods for detecting those conditions.

The Accuracy of an Ambulatory Level III Sleep Study Compared to a Level I Sleep Study for the Diagnosis of Sleep-Disordered Breathing in Children With Neuromuscular Disease

STUDY OBJECTIVES

Polysomnography (PSG) surveillance recommendations are not being met for children with neuromuscular disease (NMD) because of limited diagnostic facilities. We evaluated the diagnostic accuracy of an ambulatory level III device as compared to a level I PSG.

METHODS

A cross-sectional study was conducted at a tertiary pediatric institution. Eligibility criteria included: (1) children with NMD; (2) age 6 to 18 years; (3) booked for a clinically indicated overnight level I PSG. Participants were randomized to an overnight level I PSG followed by an ambulatory level III study with end tidal carbon dioxide (etCO₂) or vice versa. Sensitivity and specificity of the ambulatory level III device to diagnose sleep-disordered breathing (SDB) at an apnea-hypopnea index (AHI) cutoff of > 1.0 events/h was the primary outcome.

RESULTS

Moderate to severe SDB was found in 46% of participants (13/28). The device's sensitivity and specificity to detect SDB was 61.5% and 86.7%, respectively. The positive predictive value of the level III study was 80.0% and the negative predictive value was 72.0%. Fifty percent of the cohort were either missing or had incomplete or falsely low ambulatory etCO₂ data.

CONCLUSIONS

A level III device with etCO₂ is not yet able to be implemented in clinical practice as a diagnostic tool for SDB in pediatric patients with NMD.

COMMENTARY

A commentary on this article appears in this issue on page 1973.

Diagnosis and perioperative management in pediatric sleep-disordered breathing

Sleep-disordered breathing has a prevalence of 12% in the pediatric population. It represents a spectrum of disorders encompassing abnormalities of the upper airway that lead to sleep disruption, including primary snoring, obstructive sleep apnea, central sleep apnea, and sleep-related hypoventilation. Sleep-disordered breathing is the most common indication for adenotonsillectomy, one of the most common procedures performed in children. In recent years, the American Academy of Otolaryngology-Head and Neck Surgery, American Academy of Pediatrics, and the American Society of Anesthesiologists have crafted guidelines to help safely manage children with sleep-disordered breathing. Each organization recommends in-laboratory polysomnography for definitive diagnosis of obstructive sleep apnea in certain cases. However, because this test is both costly and inconvenient, there has been significant interest in alternative methods for diagnosing clinically significant sleep-disordered breathing. Accurate diagnosis is critical because sleep-disordered breathing confers certain perioperative risks and increased mortality in some instances. Recent studies have elucidated the danger of anesthesia and opioids in worsening obstructive sleep apnea, and recommendations for alternative analgesia are being created. In addition, determining the most appropriate level and duration of monitoring in the postoperative period is actively being evaluated. This article presents an overview of the recent literature on the perioperative care of pediatric patients with sleep-disordered breathing. It highlights innovative modalities and limitations in diagnosing obstructive sleep apnea, the importance of a tailored anesthetic/analgesic approach to children with obstructive sleep apnea, and the need for postoperative monitoring. It also brings to focus that further studies on the perioperative care of these children are necessary.

The Impact of Altitude on Sleep-Disordered Breathing in Children Dwelling at High Altitude: A Crossover Study

Study Objectives

Sleep-disordered breathing (SDB) is prevalent among children and is associated with adverse health outcomes. Worldwide, approximately 250 million individuals reside at altitudes higher than 2000 meters above sea level (masl). The effect of chronic high-altitude exposure on children with SDB is unknown. This study aims to determine the impact of altitude on sleep study outcomes in children with SDB dwelling at high altitude.

Methods

A single-center crossover study was performed to compare results of high-altitude home polysomnography (H-PSG) with lower altitude laboratory polysomnography (L-PSG) in school-age children dwelling at high altitude with symptoms consistent with SDB. The primary outcome was apnea-hypopnea index (AHI), with secondary outcomes including obstructive AHI; central AHI; and measures of oxygenation, sleep quality, and pulse rate.

Results

Twelve participants were enrolled, with 10 included in the final analysis. Median altitude was 1644 masl on L-PSG and 2531 masl on H-PSG. Median AHI was 2.40 on L-PSG and 10.95 on H-PSG. Both obstructive and central respiratory events accounted for the difference in AHI. Oxygenation and sleep fragmentation were worse and pulse rate higher on H-PSG compared to L-PSG.

Conclusions

These findings reveal a clinically substantial impact of altitude on respiratory, sleep, and cardiovascular outcomes in children with SDB who dwell at high altitude. Within this population, L-PSG underestimates obstructive sleep apnea and central sleep apnea compared to H-PSG. Given the shortage of high-altitude pediatric sleep laboratories, these results suggest a role for home sleep apnea testing for children residing at high altitude.

Sleep disordered breathing in enuretic children and controls

INTRODUCTION

Nocturnal enuresis and sleep disordered breathing are common childhood problems that are reported to be associated with each other. Sleep disordered breathing is often found in children with upper airway obstruction and, according to some studies, its presence is associated with an increased risk of nocturnal enuresis. Respiration during sleep in children with therapy-resistant enuresis, but no history of snoring or sleep apneas, has previously been investigated, and subclinical signs of disordered respiration were found in this group. However, sleep disordered breathing in enuretic children without a history of snoring or sleep apneas has not been thoroughly studied before.

AIM

To evaluate sleep disordered breathing in enuretic children and compare them with healthy control children.

SUBJECTS AND METHODS

Children aged 8-13 years with nocturnal enuresis were included. Exclusion criteria were: daytime incontinence, on-going anti-enuretic treatment, and concomitant urological, endocrinological, nephrological or psychiatric disorders. Twenty children (19 boys and 1 girl) suffering from therapy-resistant nocturnal enuresis, and 21 healthy controls (18 boys and 3 girls) underwent one night of polygraphic sleep registration focused on respiratory variables. The registration included electroencephalography as well as assessment of respiratory movements, nasal airflow and oxygen saturation; it was performed with a portable sleep device at the subjects' homes. In addition to this, OSA 18, a health-related quality of life instrument, was used to evaluate subjective issues related to sleep and breathing.

RESULTS

The mean apnea hypopnea index values were 0.96 ± 0.8 for the patient group and 0.46 ± 0.4 for the control group. The oxygen desaturation index was slightly higher for the children with nocturnal enuresis compared with the healthy controls (P = 0.05). No other differences were found in the respiratory variables. Both groups of children showed low levels of arousals (Summary Table). The enuretic children reported significantly more subjective sleep disturbances and a lower quality of life than their healthy peers.

DISCUSSION

This was the first controlled study of sleep disordered breathing in children with nocturnal enuresis. One limitation of the study was that some variables were known to be underestimated when scoring polygraphic data. The apnea hypopnea index was such a variable and was indeed lower than in a previous study.

CONCLUSION

No major differences in respiration during sleep were found between enuretic children and controls.

American Academy of Sleep Medicine Position Paper for the Use of a Home Sleep Apnea Test for the Diagnosis of OSA in Children

INTRODUCTION

The purpose of this position paper is to establish the American Academy of Sleep Medicine's (AASM) position on the use of a home sleep apnea test (HSAT) for the diagnosis of obstructive sleep apnea (OSA) in children (birth to 18 years of age).

METHODS

The AASM commissioned a task force of 8 experts in sleep medicine to review the available literature on the use of an HSAT to diagnose OSA in children. The task force developed the position statement based on a thorough review of these studies and their clinical expertise. The AASM Board of Directors approved the final position statement.

POSITION STATEMENT

Use of a home sleep apnea test is not recommended for the diagnosis of obstructive sleep apnea in children. 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.

Comparison of home sleep apnea testing versus laboratory polysomnography for the diagnosis of obstructive sleep apnea in children

INTRODUCTION

Obstructive sleep apnea (OSA) affects 1-5% of pediatric patients. Laboratory polysomnography is expensive, not always available, and is inconvenient for patients. Our study investigates the diagnostic ability of an unattended ambulatory monitor for the diagnosis of pediatric OSA.

METHODS

A prospective study was conducted in children, ages 2-17. Subjects completed in-lab polysomnography simultaneously with ambulatory monitoring. Caregivers attempted home studies on two subsequent nights to compare the home monitor and the laboratory polysomnogram (PSG).

RESULTS

Thirty-three subjects completed simultaneous laboratory polysomnogram with portable monitoring. Twenty patients completed home studies, with 16 completing 2 nights of monitoring. The measurement of AHI by the portable monitor was different than that obtained by the PSG with statistical significance for the comparisons of PSG vs. In-Lab (p = 0.0026), PSG vs. Home 1 (p = 0.033), and PSG vs. Home 2 (p = 0.033). The sensitivity of the portable monitor for diagnosing OSA was best for the In-lab use at 81%, but only 69% and 70% for the uses at home on the 2 nights respectively. Interestingly, the comparison of AHI and lowest oxygen saturation measurements from the home sleep test in children age 6 and older did not differ significantly from the PSG.

CONCLUSIONS

This pilot study demonstrated differences between home sleep testing and in-lab polysomnography for the diagnosis of pediatric sleep apnea. These differences were predominantly found to exist in younger children. Larger prospective studies are needed prior to widespread use, but home studies may alleviate issues of access to care and higher costs of laboratory polysomnography.

Assessment of Sleep in Children with Autism Spectrum Disorder

Sleep disturbances in children with autism spectrum disorder (ASD) are significantly more prevalent than found in typically developing (TD) children. Given the detrimental impact of poor sleep on cognitive, emotional, and behavioral functioning, it is imperative to screen and assess for sleep disturbances in this population. In this paper, we describe the screening and assessment process, as well as specific measures commonly used for assessing sleep in children with ASD. Advantages and limitations for use in children with ASD are discussed. While subjective measures, such as parent-report questionnaires and sleep diaries, are the most widely used, more objective measures such as actigraphy, polysomnography, and videosomnography provide additional valuable information for both diagnostic purposes and treatment planning. These objective measures, nonetheless, are limited by cost, availability, and feasibility of use with children with ASD. The current review provides an argument for the complementary uses of both subjective and objective measures of sleep specifically for use in children with ASD.

Sleep-disordered breathing in children with Down syndrome: Usefulness of home polysomnography

OBJECTIVE

To investigate the technical feasibility of unattended home polysomnography (HPSG) in children with Down syndrome.

METHODS

Data from children with Down syndrome under 10 years of age referred to a diagnostic sleep study was analyzed. A full sleep-lab based polysomnography (PSG) or a HPSG with a portable device was performed. Uninterpretable HPSGs were defined as: recordings with (i) loss of ≥2 of the following channels: nasal flow, or thoracoabdominal sensors, or (ii) HPSG with less than 4h of artifact-free recording time or (iii) less than 4h SpO2 (peripheral capillary oxygen saturation) signal.

RESULTS

A total of 44 children (68% males) were included in the study, with a mean age of 3.6 (0.1-10) years. PSG was performed in 8 cases and HPSG in 36 cases. Six HPSG recordings were classified as uninterpretable and had to be repeated. Age, gender and BMI were no significant predictors of uninterpretability of the HPSG. Obstructive sleep apnea (OSA) was present in 61% (n=27) of all subjects, and classified as mild, moderate, and severe in 43% (n=19), 11% (n=5), and 7% (n=3) of cases, respectively. Interpretable and technically acceptable HPSGs were obtained in 30 subjects (83%). Age, gender and BMI were no significant predictors for interpretability of the HPSG.

DISCUSSION

This study demonstrates that a portable polysomnographic home device may be helpful for diagnosing OSA in children with Down syndrome. Considering the potential consequences of untreated OSA, this screening test may be helpful for early diagnosis of OSA in children with Down syndrome.

Pediatric Home Sleep Apnea Testing: Slowly Getting There!

Pediatric OSA can result in significant neurocognitive, behavioral, cardiovascular, and metabolic morbidities. Prompt diagnosis and treatment are, therefore, of paramount importance. The current gold standard for diagnosis of OSA in children is in-laboratory polysomnography (PSG). Home sleep apnea testing has been considered as an alternative as it is potentially more cost effective, convenient, and accessible. This review concentrates mainly on the use of type 2 and 3 portable monitoring devices. The current evidence on the feasibility and diagnostic accuracy of home testing in the diagnosis of pediatric OSA was examined. Overall, the evidence in children is limited. Feasibility studies that have been performed have on the whole shown good results, with several reporting > 90% of their home recordings as meeting predetermined quality criteria regarding signal artifact and minimum recording time. The limited data comparing type 2 studies with in-laboratory PSG have shown no significant differences in respiratory parameters. The results pertaining to diagnostic accuracy of type 3 home sleep apnea testing devices are conflicting. Although more research is needed, home testing with at least a type 3 portable monitor offers a viable alternative in the diagnosis of otherwise healthy children with moderate to severe OSA, particularly in settings where access to polysomnography is scarce or unavailable. Of note, since most studies have been performed in habitually snoring healthy children, home sleep apnea testing may not be applicable to children with other comorbid conditions. In particular, CO2 monitoring is important in children in whom there is concern regarding nocturnal hypoventilation, such as children with neuromuscular disease, underlying lung disease, or obesity hypoventilation, and most home testing devices do not include a transcutaneous or end-tidal CO2 channel.