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Analysis of large-volume data holds promise for improving the application of precision medicine to sleep, including improving identification of patient subgroups who may benefit from alternative therapies. Big data used within the health care system also promises to facilitate end-to-end screening, diagnosis, and management of sleep disorders; improve the recognition of differences in presentation and susceptibility to sleep apnea; and lead to improved management and outcomes. To meet the vision of personalized, precision therapeutics and diagnostics and improving the efficiency and quality of sleep medicine will require ongoing efforts, investments, and change in our current medical and research cultures., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The American Academy of Sleep Medicine (AASM) Sleep Apnea Definitions Task Force reviewed the current rules for scoring respiratory events in the 2007 AASM Manual for the Scoring and Sleep and Associated Events to determine if revision was indicated. The goals of the task force were (1) to clarify and simplify the current scoring rules, (2) to review evidence for new monitoring technologies relevant to the scoring rules, and (3) to strive for greater concordance between adult and pediatric rules. The task force reviewed the evidence cited by the AASM systematic review of the reliability and validity of scoring respiratory events published in 2007 and relevant studies that have appeared in the literature since that publication. Given the limitations of the published evidence, a consensus process was used to formulate the majority of the task force recommendations concerning revisions.The task force made recommendations concerning recommended and alternative sensors for the detection of apnea and hypopnea to be used during diagnostic and positive airway pressure (PAP) titration polysomnography. An alternative sensor is used if the recommended sensor fails or the signal is inaccurate. The PAP device flow signal is the recommended sensor for the detection of apnea, hypopnea, and respiratory effort related arousals (RERAs) during PAP titration studies. Appropriate filter settings for recording (display) of the nasal pressure signal to facilitate visualization of inspiratory flattening are also specified. The respiratory inductance plethysmography (RIP) signals to be used as alternative sensors for apnea and hypopnea detection are specified. The task force reached consensus on use of the same sensors for adult and pediatric patients except for the following: (1) the end-tidal PCO(2) signal can be used as an alternative sensor for apnea detection in children only, and (2) polyvinylidene fluoride (PVDF) belts can be used to monitor respiratory effort (thoracoabdominal belts) and as an alternative sensor for detection of apnea and hypopnea (PVDFsum) only in adults.The task force recommends the following changes to the 2007 respiratory scoring rules. Apnea in adults is scored when there is a drop in the peak signal excursion by ≥ 90% of pre-event baseline using an oronasal thermal sensor (diagnostic study), PAP device flow (titration study), or an alternative apnea sensor, for ≥ 10 seconds. Hypopnea in adults is scored when the peak signal excursions drop by ≥ 30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative sensor, for ≥ 10 seconds in association with either ≥ 3% arterial oxygen desaturation or an arousal. Scoring a hypopnea as either obstructive or central is now listed as optional, and the recommended scoring rules are presented. In children an apnea is scored when peak signal excursions drop by ≥ 90% of pre-event baseline using an oronasal thermal sensor (diagnostic study), PAP device flow (titration study), or an alternative sensor; and the event meets duration and respiratory effort criteria for an obstructive, mixed, or central apnea. A central apnea is scored in children when the event meets criteria for an apnea, there is an absence of inspiratory effort throughout the event, and at least one of the following is met: (1) the event is ≥ 20 seconds in duration, (2) the event is associated with an arousal or ≥ 3% oxygen desaturation, (3) (infants under 1 year of age only) the event is associated with a decrease in heart rate to less than 50 beats per minute for at least 5 seconds or less than 60 beats per minute for 15 seconds. A hypopnea is scored in children when the peak signal excursions drop is ≥ 30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative sensor, for ≥ the duration of 2 breaths in association with either ≥ 3% oxygen desaturation or an arousal. In children and adults, surrogates of the arterial PCO(2) are the end-tidal PCO(2) or transcutaneous PCO(2) (diagnostic study) or transcutaneous PCO(2) (titration study). For adults, sleep hypoventilation is scored when the arterial PCO(2) (or surrogate) is > 55 mm Hg for ≥ 10 minutes or there is an increase in the arterial PCO(2) (or surrogate) ≥ 10 mm Hg (in comparison to an awake supine value) to a value exceeding 50 mm Hg for ≥ 10 minutes. For pediatric patients hypoventilation is scored when the arterial PCO(2) (or surrogate) is > 50 mm Hg for > 25% of total sleep time. In adults Cheyne-Stokes breathing is scored when both of the following are met: (1) there are episodes of ≥ 3 consecutive central apneas and/or central hypopneas separated by a crescendo and decrescendo change in breathing amplitude with a cycle length of at least 40 seconds (typically 45 to 90 seconds), and (2) there are five or more central apneas and/or central hypopneas per hour associated with the crescendo/decrescendo breathing pattern recorded over a minimum of 2 hours of monitoring.

Compelling data demonstrate a strong association between sleep-disordered breathing (SDB) and cardiovascular disorders. The association is most consistent between obstructive sleep apnea (OSA) and hypertension. Epidemiologic and clinic-based studies provide evidence for an etiological role of OSA in hypertension, independent of obesity. Furthermore, several studies suggest amelioration of hypertension with therapy for sleep apnea. Emerging data also suggest a role for OSA in causing coronary artery disease. This association is bolstered by evidence suggesting that continuous positive airway pressure (CPAP) therapy improves early signs of atherosclerosis and may impede progression to clinically important cardiovascular disease. SDB (both OSA and central sleep apnea) is frequently observed in patients with heart failure. OSA may be a risk factor for incident heart failure. The current data do not provide consistent evidence for whether treatment of SDB will improve survival or other end points in patients with heart failure, and larger trials are currently underway to better elucidate that relationship. Substantial evidence also links SDB to an increased risk of various arrhythmias. Treatment of SDB with CPAP appears to significantly attenuate that risk. Finally, several studies suggest SDB as a risk factor for stroke. Whether treatment of SDB reduces stroke risk, however, remains to be determined. In conclusion, persuasive data provide evidence for an association, probably causal, between sleep-disordered breathing and several cardiovascular disorders. Large randomized controlled trials will further help confirm the association and elucidate the cardiovascular benefits of SDB therapy.

Background: Studies examining sleep in the hemodialysis (HD) population have largely lacked an adequate comparison group. It therefore is uncertain whether poor sleep quality in the HD population reflects age, chronic health conditions, or effects of conventional HD therapy., Study Design: Cross-sectional matched-group study., Setting & Participants: Forty-six in-center HD patients were compared with 137 community participants participating in the Sleep Heart Health Study matched for age, sex, body mass index, and race., Predictor: HD patients compared with community-dwelling non-HD participants., Outcomes & Measurements: Home unattended polysomnography was performed and scored by using similar protocols. Sleep habits and sleepiness were assessed by using the Sleep Habits Questionnaire and Epworth Sleepiness Scale., Results: Average age of study samples was 63 years, 72% were white, and average body mass index was 28 +/- 5 kg/m(2). HD patients were significantly more likely than community participants to have short sleep (odds ratio, 3.27; 95% confidence interval, 1.16 to 9.25) and decreased sleep efficiency (odds ratio, 5.5; 95% confidence interval, 1.5 to 19.6). HD patients reported more difficulty getting back to sleep (odds ratio, 2.25; 95% confidence interval, 1.11 to 4.60) and waking up too early (odds ratio, 2.39; 95% confidence interval, 1.01 to 5.66). There was no association between polysomnography sleep time and self-reported sleep time (r = 0.09; P = 0.6) or between the Epworth Sleepiness Scale and severity of sleep apnea (r = 0.10; P = 0.5) in the HD population., Limitations: The study was limited to participants older than 45 years., Conclusions: Kidney failure treated with thrice-weekly HD is significantly associated with poor subjective and objective sleep quality.

The American Academy of Sleep Medicine Task Force on Respiratory Scoring reviewed the evidence that addresses: the validity of specific sensors in detecting airflow, tidal volume, oxyhemoglobin saturation, and CO2; the reliability of specific scoring approaches for quantifying sleep related breathing disorders (SRBD); and the validity of using various definitions of the apnea hypopnea index (AHI) as assessed by the strength and consistency of associations with several comorbidities (hypertension, cardiovascular disease, sleepiness, impaired quality of life, and accidents). The evidence was based on a literature search of relevant articles published through December 2004, which resulted in identifying and extracting data from 182 articles, which were graded using standardized approaches. Diverse physiological sensors have been utilized to quantify airflow limitation in patients with suspected SRBD. Although thermistry appears appropriate for identifying apneas, the available evidence did not indicate it provides valid quantification of airflow reduction. The emerging evidence evaluating the accuracy of signal detection against the gold standard measurements (e.g., pneumotachography) suggested the superiority of inductance plethysmography and nasal pressure transducers for detection of hypopneas, with some evidence that recordings from a nasal pressure transducer may better approximate flow/volume than uncalibrated inductance plethysmography. However, since the nasal pressure transducer has only recently been incorporated into large-scale studies, there are as of yet few data that address the predictive value of transducer-identified events relative to clinical or physiological outcomes. Very few studies directly compared the validity of alternative approaches for defining the duration, amplitude change, and use of corroborative data from desaturation or arousal for defining hypopneas. Many observational studies utilizing various designs and approaches for event detection have shown significant associations between measures of SRBD and health outcomes. Data from the 2 largest sleep cohort studies, the Sleep Heart Health Study and the Wisconsin Sleep Cohort, both used definitions of hypopneas based on "discernible" reductions of inductance plethysmography signals with associated desaturation and showed that the derived AHIs using these hypopnea definitions correlated with various indices of morbidity. However, it is not clear whether alternative definitions would provide comparable if not better prediction, or whether optimal approaches for event identification would vary for different outcomes. Despite these limitations, forming a consensus on optimal approaches for recording and measuring respiratory events is an important step toward generating data from different clinical or research laboratories that can be compared. However, additional research is needed, including direct comparisons of alternative measuring approaches for predicting clinical outcomes, with a need to address these issues in large samples across the age spectrum and with inclusion of promising new technology.

Sleep disordered breathing is frequently associated with repeated arousals and hypoxia resulting from intermittent partial or complete collapse of upper airway during sleep. There is an emerging recognition of the association of this disorder with metabolic abnormalities, coronary artery disease, congestive heart failure and hypertension. Of these conditions, the data associating obstructive sleep apnea and hypertension are the most compelling. This review evaluates the recent literature investigating this association and identifies areas where additional research is needed.

Study Objectives: The results of small studies have suggested that a nasal-cannula pressure transducer has a higher sensitivity than a thermistor in detecting hypopneas and diagnosing sleep-disordered breathing in both adults and children. We compared a thermistor alone, and in conjunction with a pressure transducer, for detection of sleep-disordered breathing in children during in-home polysomnography., Design: Retrospective analysis of a subsample of a prospective cohort study., Setting: Students attending elementary school in the Tucson Unified School District., Participants: A subsample of the Tucson Children's Assessment of Sleep Apnea study population., Measurements and Results: Polysomnographic recordings of 40 children (24 girls and 16 boys, mean age 9.2 +/- 1.7 years; range 6-11 years) were analyzed to compare the detection of sleep-disordered breathing events by 2 different methods of measuring airflow: thermistor alone and thermistor with nasal-cannula pressure transducer (transducer) used simultaneously. The transducer detected all the respiratory events detected by the thermistor, but the thermistor detected only 84% of the transducer-defined events. Consequently, the transducer-derived mean respiratory disturbance index was higher than that detected by the thermistor (7.0 +/- 3.8 vs 5.9 +/- 3.4, P < .001). The bias error between transducer respiratory disturbance index and thermistor respiratory disturbance index on a Bland-Altman plot was 1.08 (95% confidence interval, 0.8 - 1.4). There was good agreement between the thermistor and the transducer for making the diagnosis of sleep apnea using a cutoff of a respiratory disturbance index greater than 5 (kappa = 0.69). The quality of the tracings with the transducer was comparable to that of the thermistor, but the transducer dislodged more frequently., Conclusion: The use of a nasal transducer in conjunction with a thermistor was more sensitive than the thermistor alone in detecting sleep-disordered breathing in children during unattended polysomnography.