Validierung von SleepMinder® zur Erfassung der Schlafqualität bei Patienten mit OSAS

Background

Polysomnography (PSG) is the gold standard for diagnosis of sleep-disordered breathing (SDB). As PSG is time-consuming and labor-intensive it is the last step in a step-wise diagnostic.

Aim

This study assessed the validity of SleepMinder® (Resmed Sensor Technologies, Dublin, Ireland) for the detection of total sleep time (TST) and sleep efficiency (SE).

Materials and methods

SleepMinder® is a non-contact device using weak radiowaves to measure respiration and sleep quality. Diagnostic accuracy of SleepMinder® was studied in a cohort of 57 patients admitted to the sleep laboratory due to suspected SDB. Results obtained by SleepMinder® were compared with those of a simultaneous PSG to assess the diagnostic accuracy of SleepMinder®. Additionally we examined the influence of periodic limb movements on the diagnostic accuracy of SleepMinder®.

Results

SleepMinder® overestimates TST compared to TST estimated by PSG. Comparison between the results in TST estimation of PSG and SleepMinder® showed a deviation of 5?% in group 1 (AHI < 15/h) and 6?% in group 2 (AHI ≥ 15/h) without a statistically significant difference between the groups. Compared to PSG-detected TST in SleepMinder® analysis 51?% of the patients had a deviation < 10?%, 70?% a deviation < 20?% and in 9?% a deviation ≥ 30?%. The systemic bias was 24 min. Comparing SE_SleepMinder with SE_PSG, we found a deviation of 1?% for group 1 whereas we obtained a deviation of 7?% for group 2 (p = n .s.) without a statistically significant difference between the groups. Comparing SE_SleepMinder and SE_PSG, in our cohort 16 (28?%) patients showed a deviation < 5?%, 28 (49?%) patients had a deviation < 10?%, 38 (6?%) < 20?% and 4 (7?%) patients had a 30?% deviation. Furthermore, a 2?% overestimation by SleepMinder could be found.

Conclusion

SleepMinder® estimates TST and SE with moderate accuracy. Therefore, measuring these parameters can be an additional and helpful feature in SBD screening.

     

Behavioral Correlates of Sleep-Disordered Breathing in Older Men

Study Objectives:

To examine the association between sleep-disordered breathing (SDB) and subjective measures of daytime sleepiness, sleep quality, and sleep-related quality of life in a large cohort of community-dwelling older men and to determine whether any association remained after adjustment for sleep duration.

Design:

Cross-sectional. The functional outcome measures of interest were daytime sleepiness (Epworth Sleepiness Scale, ESS), sleep-related symptoms (Pittsburgh Sleep Quality Index, PSQI), and sleep-related quality of life (Functional Outcomes of Sleep Questionnaire, FOSQ). Analysis of variance and adjusted regression analyses examined the association between these outcome measures and SDB severity and actigraphy-determined total sleep time (TST). We then explored whether associations with SDB were confounded by sleep duration by adjusting models for TST.

Setting:

Community-based sample in home and research clinic settings.

Participants:

Two-thousand eight-hundred forty-nine older men from the multicenter Osteoporotic Fractures in Men Study that began in 2000. All participants underwent in-home polysomnography for 1 night and wrist actigraphy for a minimum of 5 consecutive nights.

Interventions:

N/A.

Measurements and Results:

Participants were aged 76.4 ± 5.5 years and had an apnea-hypopnea index (AHI) of 17.0 ± 15.0. AHI and TST were weakly correlated. ESS scores individually were modestly associated with AHI and TST, but the association with AHI was attenuated by adjustment for TST. PSQI and FOSQ scores were largely not associated with measures of SDB severity but were modestly associated with TST.

Conclusions:

Daytime sleepiness, nighttime sleep disturbances, and sleep-related quality of life were modestly associated with TST. After adjustment for TST, there was no independent association with SDB severity. These results underscore the potential differences in SDB functional outcomes in older versus young and middle-aged adults.

Citation:

Kezirian EJ; Harrison SL; Ancoli-Israel S; Redline S; Ensrud K; Goldberg AN; Claman DM; Spira AP; Stone KL. Behavioral correlates of sleep-disordered breathing in older men. SLEEP 2009;32(2):253–261.     

Is a polysomnographic recording prior to MSLT worth the effort?

Objective

It was recently proposed that polysomnography (PSG) may be replaced by actigraphy in order to obtain long-term sleep time prior to the multiple sleep latency test (MSLT). Polysomnography is used to assess sleep time and to detect and classify underlying sleep pathology. In the following article, the contribution of PSG to the diagnostic outcome of the MSLT is discussed.

Methods

MSLT referrals (n?=?81) with in-home polysomnography from the neurology (n?=?39, 23 women, 37 (±13) years) and pulmonary medicine (n?=?42, 20 women, 41 (±14) years) departments were analyzed. The diagnostic outcomes of the PSG and MSLT were examined.

Results

Median total sleep time prior to MSLT was 362 (range, 156–530) min. Sleep apnea (respiratory disturbance index >?15/h and >?30/h) was diagnosed in 21 and 19 patients, respectively. Periodic limb movements (PLM) were identified in 5 patients; 3 of these had a PLM arousal index >?5/h. Sleep onset REM (SOREM) was detected during PSG in 5 patients; 4 of these also had SOREM in the MSLT.

Conclusion

PSG combined with MSLT was found to improve diagnostic outcome and is highly useful for recognition of sleep-related pathology. Various sleep disorders remain undetected if ACT alone is used prior to MSLT procedures.     

Predictors of obstructive sleep apnea

Background

A patient’s condition, such as obesity, plays a key role in the pathophysiology of obstructive sleep apnea (OSA). This study focuses on morphometric data that might be associated with the apnea–hypopnea index (AHI) and could therefore be used to predict OSA in order to better select patients for cardiorespiratory polysomnography (PSG).

Methods

Data of 110 patients with suspected OSA in the sleep center outpatient department were analyzed retrospectively. The data included morphometric measurements such as neck, waist, and hip circumference; weight; body size; age; and Epworth Sleepiness Scale (ESS). The results of the patients’ overnight polygraphy, the AHI, completed the data.

Results

Neck and waist circumference can predict the AHI (p < 0.01). Power of prediction was higher for both factors among male (p < 0.01) compared to female patients (p = 0.05). In the case of neck circumference, the threshold value is 40 cm. Neck circumferences of more than 40 cm are strongly associated with a higher AHI (p < 0.001).

Conclusion

It was possible to confirm the roles of waist and neck circumference as important parameters for a prediction model. Nevertheless, these parameters alone are not precise enough to completely neglect factors such as anatomic morphology in order to predict OSA and its severity.

     

Validation of a Portable Monitoring System for the Diagnosis of Obstructive Sleep Apnea Syndrome

Study Objective:

To evaluate if a portable monitor could accurately measure the apnea-hypopnea index (AHI) in patients with a suspicion of obstructive sleep apnea (OSA).

Design:

Prospective and randomized.

Setting:

Sleep laboratory.

Participants:

80 participants: 70 patients with clinical OSA suspicion and 10 subjects without suspicion of OSA.

Interventions:

N/A

Measurements and Results:

Three-order randomized evaluations were performed: (1) STD (Stardust II) used at the participants'' home (STD home), (2) STD used simultaneously with PSG in the sleep lab (STD+PSG lab), and (3) PSG performed without the STD (PSG lab). Four AHI values were generated and analyzed: (a) STD home; (b) STD from STD+PSG lab; (c) PSG from STD+PSG (named PSG+STD lab); and (d) PSG lab. Two technicians, blinded to study details, performed the analyses of all evaluations. There was a strong correlation between AHI from the STD and PSG recordings for all 4 AHI values (all correlations above 0.87). Sensitivity, specificity, and positive and negative predictive values at AHI cut-off values of 5, 15, and 30 events/hour were calculated. AHI values from the PSG lab and PSG+STD lab were compared to STD home and STD+PSG lab and showed the best results when STD and PSG were performed simultaneously. In all analyses, the area under ROC curve was at least 0.90. With multiple comparisons, diagnostic agreement was between 91% and 75%. The Bland Altman analyses showed strong agreement between AHI values from the STD and PSG recordings, especially when comparing the AHI from simultaneous STD and PSG recordings.

Conclusion:

These data suggest that the STD is accurate in confirming the diagnosis of OSA where there is a suspicion of the disorder. Better agreement occurred during simultaneous recordings.

Citation:

Santos-Silva R; Sartori DE; Truksinas V; Truksinas E; Alonso FFFD; TufikS; Bittencourt LRA. Validation of a portable monitoring system for the diagnosis of obstructive sleep apnea syndrome. SLEEP 2009;32(5):629-639.     

Effekte einer adaptiven Servoventilation auf Herzrhythmusstörungen bei Patienten mit chronischer Herzinsuffizienz und schlafbezogenen Atmungsstörungen

Background

In patients with chronic heart failure with reduced left ventricular ejection fraction (HFrEF) sleep-disordered breathing (SDB) is linked with an increased risk for nocturnal cardiac arrhythmias. SDB can be effectively treated with adaptive servo-ventilation (ASV). Therefore, we tested the hypothesis that ASV therapy reduces nocturnal arrhythmias and heart rate in patients with HFrEF and SDB.

Methods

In a non-prespecified subanalysis of a multicenter randomized-controlled trial (ISRCTN04353156) twenty consecutive patients with stable HFrEF (age 67 ± 9 y; left ventricular ejection fraction 32 ± 7?%) and SDB (apnea-hypopnea index, AHI 48 ± 20/h) were randomized to either ASV (n = 10; Philips Respironics, Murrysville, PA, USA) or optimal medical treatment alone (control, n = 10). Polysomnography (PSG) with centralized scoring and blinded analysis where obtained at baseline and 12 weeks. The electrocardiograms (ECG) of the PSGs were analyzed with 24 h-Holter electrocardiography software (Pulse Biomedical Inc., QRS-Card^TM Cardiology Suite, USA).

Results

There was a decrease in ventricular ectopic beats (VEBs) per hour recording time in the ASV-group compared to the control group (?8.1 ± 42.4 versus +9.8 ± 63.7/h, p = 0.356). ASV reduced the number of ventricular couplets as well as non-sustained ventricular tachycardias (nsVT) compared to the control-group (?2.3 ± 6.9 versus +2.1 ± 12.7/h, p = 0.272, and ?0.1 ± 0.5 versus +0.1 ± 1.1/h, p = 0.407, respectively). Mean nocturnal heart rate decreased in the ASV group compared to the control-group (?2.0 ± 2.7 versus +3.9 ± 11.5/minute, p = 0,169). Described changes were not significantly different between groups.

Conclusions

In HFrEF patients with SDB ASV treatment may reduce nocturnal ventricular ectopic beats, couplets, nsVT and mean nocturnal heart rate. Findings underscore the need for further analyses in larger studies.

     

Sleep Disordered Breathing,Daytime Symptoms,and Functional Performance in Stable Heart Failure

Study Objectives:

To evaluate characteristics of sleep disordered breathing (SDB); clinical and demographic correlates of SDB; and the extent to which SDB explains functional performance and symptoms in stable heart failure patients receiving care in structured HF disease management programs.

Design:

Cross-sectional, observational study.

Setting:

Structured heart failure disease management programs.

Participants:

170 stable chronic heart failure patients (mean age = 60.3 ± 16.8 years; n = 60 [35%] female; n = 50 [29%] African American; left ventricular ejection fraction mean = 32 ± 14.6).

Interventions:

N/A

Measurements and Results:

Full polysomnography was obtained for one night on participants in their homes. Participants completed the 6-minute walk, 3 days of actigraphy, MOS-SF 36, Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, Multi-Dimensional Assessment of Fatigue Scale, and the Centers for the Epidemiological Studies of Depression Scale. Fifty-one percent had significant SDB; Sixteen (9%) of the total sample had central sleep apnea. Severe SDB was associated with a 4-fold increase in the likelihood of poor self-reported physical function (OR = 4.15, 95%CI = 1.19–14.57) and CSA was associated with low levels of daytime mobility (OR = 4.09, 95%CI = 1.23–13.62) after controlling for clinical and demographic variables. There were no statistically significant relationships between SDB and daytime symptoms or self-reported sleep, despite poorer objective sleep quality in patients with SDB.

Conclusions:

Severe SDB is associated with poor physical function in patients with stable HF but not with daytime symptoms or self-reported sleep, despite poorer objective sleep quality in patients with SDB.

Citation:

Redeker NS; Muench U; Zucker MJ; Walsleben J; Gilbert M; Freudenberger R; Chen M; Campbell D; Blank L; Berkowitz R; Adams L; Rapoport DM. Sleep disordered breathing, daytime symptoms, and functional performance in stable heart failure. SLEEP 2010;33(4):551-560.     

Perception of sleep

Question of the study

The aim of the study was to examine subjective sleep perception not only in patients with insomnia but also in other sleep disorders.

Subjects and methods

A total of 159 patients with insomnia, sleep-related movement disorders (SMD), hypersomnia, and parasomnia underwent full cardiorespiratory polysomnography with videometry during two consecutive nights. In addition, patients filled in sleep logs assessing subjective sleep parameters as well as several questionnaires including the Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Center for Epidemiologic Studies-Depression scale (CES-D).

Results

For the second night, not only subjective sleep efficiency, total sleep time (TST), and sleep latency but also objective TST and efficiency significantly differed across diagnostic groups. Comparison between subjective and objective TST, efficiency and latency revealed insomnia patients to significantly underestimate their sleep efficiency and TST, while overestimating their sleep latency. Subjective and objective sleep efficiency as well as sleep latencies differed significantly in the SMD group. Parasomnia and hypersomnia patients only showed significant differences in sleep latencies. PSQI scores significantly differed across patient groups.

Conclusion

The PSQI is useful as a screening instrument for distinguishing between diagnostic categories of sleep disorders. Not only insomnia patients significantly misinterpreted sleep parameters, but patients with SMD, hypersomnia, and parasomnia also displayed significant misinterpretation of at least one sleep parameter.     

Neurobehavioral Dynamics Following Chronic Sleep Restriction: Dose-Response Effects of One Night for Recovery

Objective:

Establish the dose-response relationship between increasing sleep durations in a single night and recovery of neurobehavioral functions following chronic sleep restriction.

Design:

Intent-to-treat design in which subjects were randomized to 1 of 6 recovery sleep doses (0, 2, 4, 6, 8, or 10 h TIB) for 1 night following 5 nights of sleep restriction to 4 h TIB.

Setting:

Twelve consecutive days in a controlled laboratory environment.

Participants:

N = 159 healthy adults (aged 22-45 y), median = 29 y).

Interventions:

Following a week of home monitoring with actigraphy and 2 baseline nights of 10 h TIB, subjects were randomized to either sleep restriction to 4 h TIB per night for 5 nights followed by randomization to 1 of 6 nocturnal acute recovery sleep conditions (N = 142), or to a control condition involving 10 h TIB on all nights (N = 17).

Measurements and Results:

Primary neurobehavioral outcomes included lapses on the Psychomotor Vigilance Test (PVT), subjective sleepiness from the Karolinska Sleepiness Scale (KSS), and physiological sleepiness from a modified Maintenance of Wakefulness Test (MWT). Secondary outcomes included psychomotor and cognitive speed as measured by PVT fastest RTs and number correct on the Digit Symbol Substitution Task (DSST), respectively, and subjective fatigue from the Profile of Mood States (POMS). The dynamics of neurobehavioral outcomes following acute recovery sleep were statistically modeled across the 0 h-10 h recovery sleep doses. While TST, stage 2, REM sleep and NREM slow wave energy (SWE) increased linearly across recovery sleep doses, best-fitting neurobehavioral recovery functions were exponential across recovery sleep doses for PVT and KSS outcomes, and linear for the MWT. Analyses based on return to baseline and on estimated intersection with control condition means revealed recovery was incomplete at the 10 h TIB (8.96 h TST) for PVT performance, KSS sleepiness, and POMS fatigue. Both TST and SWE were elevated above baseline at the maximum recovery dose of 10 h TIB.

Conclusions:

Neurobehavioral deficits induced by 5 nights of sleep restricted to 4 h improved monotonically as acute recovery sleep dose increased, but some deficits remained after 10 h TIB for recovery. Complete recovery from such sleep restriction may require a longer sleep period during 1 night, and/or multiple nights of recovery sleep. It appears that acute recovery from chronic sleep restriction occurs as a result of elevated sleep pressure evident in both increased SWE and TST.

Citation:

Banks S; Van Dongen HPA; Maislin G; Dinges DF. Neurobehavioral dynamics following chronic sleep restriction: dose-response effects of one night for recovery. SLEEP 2010;33(8):1013–1026.     

Effects of adaptive servo-ventilation on ventricular arrhythmias in patients with stable congestive heart failure and sleep-disordered breathing

Background

Congestive heart failure patients with reduced left ventricular ejection fraction (HFrEF) and sleep-disordered breathing (SDB) are at an increased risk of nocturnal cardiac arrhythmias. SDB can be effectively treated with adaptive servo-ventilation (ASV). Therefore, we tested the hypothesis that ASV therapy reduces nocturnal arrhythmias and heart rate in patients with HFrEF and SDB.

Methods

In a non-prespecified subanalysis of a multicenter randomized controlled trial (ISRCTN04353156), 20 consecutive patients with stable HFrEF (age 67 ± 9 years; left ventricular ejection fraction, LVEF 32 ± 7?%) and SDB (apnea–hypopnea index, AHI 48 ± 20/h) were randomized to either an ASV therapy (n = 10) or an optimal medical treatment alone group (controls, n = 10). Polysomnography (PSG) with blinded centralized analysis and scoring was performed at baseline and at 12 weeks. The electrocardiograms (ECG) of the PSGs were analyzed with long-term (24-h) Holter ECG software (QRS-Card? Cardiology Suite; Pulse Biomedical Inc., King of Prussia, PA, USA).

Results

There was a decrease in ventricular extrasystoles (VES) per hour of recording time in the ASV group compared to the control group (?8.1 ± 42.4 versus +9.8 ± 63.7/h, p = 0.356). ASV reduced the number of ventricular couplets and nonsustained ventricular tachycardias (nsVT) compared to the control group (?2.3 ± 6.9 versus +2.1 ± 12.7/h, p = 0.272 and ?0.1 ± 0.5 versus +0.1 ± 1.1/h, p = 0.407, respectively). Mean nocturnal heart rate decreased in the ASV group compared to the controls (?2.0 ± 2.7 versus +3.9 ± 11.5/min, p = 0.169). The described changes were not significantly different between the groups.

Conclusion

In HFrEF patients with SDB, ASV treatment may reduce nocturnal VES, couplets, nsVT, and mean nocturnal heart rate. The findings of the present pilot study underscore the need for further analyses in larger studies.

     

The Utility of Single-Channel Nasal Airflow Pressure Transducer in the Diagnosis Of OSA at Home

Rationale:

Given the high prevalence of obstructive sleep apnea (OSA) and the demand on polysomnography (PSG), there is a need for low cost accurate simple diagnostic modalities that can be easily deployed in primary care to improve access to diagnosis.

Study Objectives:

The aim was to examine the utility of single-channel nasal airflow monitoring using a pressure transducer at home in patients with suspected OSA.

Design:

Cross-sectional study

Setting:

Laboratory and home

Participants:

The study was conducted in two populations. Consecutive patients with suspected OSA were recruited from the sleep disorders clinic at a tertiary referral center and from 6 local metropolitan primary care centers.

Interventions:

All patients answered questionnaires and had laboratory PSG. Nasal airflow was monitored for 3 consecutive nights at home in random order either before or after PSG.

Results:

A total of 193 patients participated (105 sleep clinic patients and 88 from primary care). The mean bias PSG apnea hypopnea index (AHI) minus nasal flow respiratory disturbance index (NF RDI) was –4.9 events per hour with limits of agreement (2 SD) of 27.8. NF RDI monitored over 3 nights had high accuracy for diagnosing both severe OSA (defined as PSG AHI > 30 events per hour) with area under the receiver operating characteristic curve (AUC) 0.92 (95% confidence interval (CI) 0.88-0.96) and any OSA (PSG AHI >5), AUC 0.87 (95% CI 0.80-0.94).

Conclusions:

Single-channel nasal airflow can be implemented as an accurate diagnostic tool for OSA at home in both primary care and sleep clinic populations.

Citation:

Makarie Rofail L; Wong KKH; Unger G; Marks GB; Grunstein RR. The utility of single-channel nasal airflow pressure transducer in the diagnosis of OSA at home. SLEEP 2010;33(8):1097-1105.     

Relation between ambulatory actigraphy and laboratory polysomnography in insomnia practice and research

Actigraphy is increasingly used in practice and research studies because of its relative low cost and decreased subject burden. How multiple nights of at‐home actigraphy compare to one independent night of in‐laboratory polysomnography (PSG) has not been examined in people with insomnia. Using event markers (MARK) to set time in bed (TIB) compared to automatic program analysis (AUTO) has not been systematically evaluated. Subjects (n = 30) meeting DSM‐5 criteria for insomnia and in‐laboratory PSG sleep efficiency (SE) of <85% were studied. Subjects were free of psychiatric, sleep or circadian disorders, other chronic conditions and medications that effect sleep. Subjects had an in‐laboratory PSG, then were sent home for 7 nights with Philips Actiwatch Spectrum Plus. Data were analysed using Philips Actiware version 6. Using the mean of seven nights, TIB, total sleep time (TST), SE, sleep‐onset latency (SOL) and wake after sleep onset (WASO) were examined. Compared to PSG, AUTO showed longer TIB and TST and less WASO. MARK only differed from PSG with decreased WASO. Differences between the PSG night and the following night at home were found, with better sleep on the first night home. Actigraphy in people with insomnia over seven nights is a valid indicator of sleep compared to an independent in‐laboratory PSG. Event markers increased the validity of actigraphy, showing no difference in TIB, TST, SE and SOL. AUTO was representative of SE and SOL. Increased SE and TST without increased TIB suggests possible compensatory sleep the first at night home after in‐laboratory PSG.     

Associations of Moderate to Severe Asthma with Obstructive Sleep Apnea

Purpose

This study aimed to evaluate the correlation between associating factors of moderate to severe asthma with obstructive sleep apnea (OSA).

Materials and Methods

One hundred and sixty-seven patients who visited the pulmonary and sleep clinic in Severance Hospital presenting with symptoms of sleep-disordered breathing were evaluated. All subjects were screened with ApneaLink. Thirty-two subjects with a high likelihood of having OSA were assessed with full polysomnography (PSG).

Results

The mean age was 58.8±12.0 years and 58.7% of subjects were male. The mean ApneaLink apnea-hypopnea index (AHI) was 12.7±13.0/hr. The mean ApneaLink AHI for the 32 selected high risk patients of OSA was 22.3±13.2/hr, which was lower than the sleep laboratory-based PSG AHI of 39.1±20.5/hr. When OSA was defined at an ApneaLink AHI ≥5/hr, the positive correlating factors for OSA were age, male gender, and moderate to severe asthma.

Conclusion

Moderate to severe asthma showed strong correlation with OSA when defined at an ApneaLink AHI ≥5/hr.     

Poor Sleep Quality is Associated with Depressive Symptoms in Patients with Heart Disease

Background

Depression in cardiac patients has gained importance due to increased mortality. Although sleep disturbances are a core symptom of depression, the prevalence and patterns of sleep disturbances in heart disease have hardly been examined regarding depression.

Purpose

This cross-sectional study aims to examine sleep disturbances and depressive symptoms in consecutively admitted cardiac patients and depressed patients.

Methods

Two hundred four inpatients (113 male, 91 female) were examined: 94 cardiac inpatients (mean age 49.3?±?14.3?years) with different heart diseases and 110 psychiatric inpatients (mean age 41.6?±?13.0?years) with depressive disorders (DP). A depressive episode according to International Classification of Diseases (ICD)-10 was also diagnosed in 14 of the cardiac patients (DCP). The Pittsburgh Sleep Quality Index (PSQI) and the Beck Depression Inventory (BDI) were used to assess subjective sleep quality and severity of depressive symptoms.

Results

Poor sleep quality (PSQI?>?5) was reported in all comorbid DCP (PSQI 12.00?±?3.53, BDI 17.86?±?4.28), in 60% of the 80 non-DCP (PSQI 5.59?±?3.73, BDI 4.47?±?3.07), and in 86.4% of the DP (PSQI 11.76?±?4.77, BDI 27.11?±?10.54). The cardiac inpatients showed a significant correlation between increased depressive symptoms and the PSQI components subjective sleep quality (r?=?0.40) and daytime dysfunction (r?=?0.34). Both sleep components were significant predictors of self-rated depression (R2?=?0.404).

Conclusions

Most cardiac patients experience poor sleep quality. Self-reported sleep disturbances in heart disease could serve as predictors of clinical or subclinical comorbid depression outside of a psychiatric setting in cardiology and other fields, and such patients should be referred to consultation-liaison psychiatry or polysomnography where sleep disorders like sleep apnea are suspected.     

Die nichtinvasive Beatmung im Schlaf

Background

Guidelines for the initiation of mechanical ventilation (MV) therapy recommend polysomnographic (PSG) and polygraphic (PG) recordings for diagnosis and control of MV efficiency. Flow signals can be heavily modified under MV therapy and are not comparable with diagnostic measurements. This article describes the interpretation of signals from PSG/PG measurements in the context of MV therapy.

Methods

Examples of PSG/PG-controlled MV therapy from the years 2000–2016 were used for this study. The interpretation of these PSG/PG signals in the context of investigating patient–ventilator synchronisation and ventilating quality is shown. Furthermore, the usefulness of incorporating internal ventilator signals, as well as long-term CO₂ measurements, into the PSG/PG recording is explained.

Results

Shape modification of flow signals in ventilator systems, detection of respiratory events, detection of patient–ventilator synchrony/asynchrony during controlled ventilation, quality of trigger sensitivity during assisted ventilation, intended and unintended leakage, as well as the assessment of automated features like auto-IPAP and auto-EPAP, are demonstrated through examples.

Conclusions

A prerequisite for good sleep quality during night-time MV is an undisturbed patient–ventilator interaction. The different types of patient–ventilator asynchronies related to the ventilator mode (controlled/assisted) can by quickly identified with PSG/PG recordings. With additional internal signals from the ventilator itself (especially leakage and breathing volume), as well as with long-term CO₂ measurements, rapid and high-quality MV initiation and control is possible.

     

The association between sleep disordered breathing, academic grades, and cognitive and behavioral functioning among overweight subjects during middle to late childhood

Study Objectives:

(1) to determine the associations of sleep disordered breathing (SDB) with behavioral functioning, cognitive test scores, and school grades during middle- to late-childhood, an under-researched developmental period in the SDB literature, and (2) to clarify whether associations between SDB and school grades are mediated by deficits in cognitive or behavioral functioning.

Design:

Cross-sectional correlative study.

Setting:

Office/hospital, plus reported functioning at home and at school.

Participants:

163 overweight subjects aged 10-16.9 years were divided into 4 groups based upon their obstructive apnea+hypopnea index (AHI) during overnight polysomnography and parent report of snoring: Moderate-Severe OSA (AHI > 5, n = 42), Mild OSA (AHI = 1-5, n = 58), Snorers (AHI < 1 + snoring, n = 26), and No SDB (AHI < 1 and nonsnoring, n = 37).

Measurements:

Inpatient overnight polysomnography, parent- and self-report of school grades and sleep, parent- and teacher-report of daytime behaviors, and office-based neuropsychological testing.

Results:

The 4 groups significantly differed in academic grades and parent- and teacher-reported behaviors, particularly inattention and learning problems. These findings remained significant after adjusting for subject sex, race, socioeconomic status, and school night sleep duration. Associations with SDB were confined to reports of behavioral difficulties in real-world situations, and did not extend to office-based neuropsychological tests. Findings from secondary analyses were consistent with, but could not definitively confirm, a causal model in which SDB affects school grades via its impact on behavioral functioning.

Conclusions:

SDB during middle- to late-childhood is related to important aspects of behavioral functioning, especially inattention and learning difficulties, that may result in significant functional impairment at school.

Citation:

Beebe DW; Ris MD; Kramer ME; Long E; Amin R. The association between sleep disordered breathing, academic grades, and cognitive and behavioral functioning among overweight subjects during middle to late childhood. SLEEP 2010;33(11):1447-1456.     

Sleep estimation using wrist actigraphy in adolescents with and without sleep disordered breathing: a comparison of three data modes

INTRODUCTION: Adolescence is a time of rapid changes in sleep habits and rising prevalence of sleepiness. The importance of measuring sleep in this population is increasingly recognized. In adults, measurements of sleep by actigraphy correlate well with sleep data from EEG recordings. Since actigraphy is increasingly utilized in adolescent sleep studies, more information is needed about reliability in this age group. This analysis investigated which actigraphy data mode is optimal for data collection in adolescents and explored the level of agreement between actigraphy and polysomnography (PSG) in population subgroups. METHODS: 181 adolescents aged 12-16 years were concurrently monitored with PSG and wrist actigraphy (measured in 3 data modes: Time Above Threshold [TAT], Zero Crossing Mode [ZCM], and Proportional Integration Mode [PIM]) to measure total sleep time (TST). RESULTS: The sample was 50% male, 55% African American, 9% with sleep disordered breathing (SDB; apnea-hypopnea index > or = 5). Intraclass correlation coefficients (ICC) for TST between actigraphy and PSG were low to moderate and were highest for TAT (0.41) compared to ZCM (0.32) and PIM (0.34). Subgroup analyses revealed that ICCs were higher among those without SDB (0.55) than those with SDB (0.00), and for girls (0.66) compared with boys (0.31). CONCLUSIONS: Results suggest that actigraphy provides a reasonably good estimate of TST in adolescents without SDB. Recognition of the variation in sleep estimates among different data collection modes, among population subgroups, and across the age spectrum, may be of fundamental importance in the interpretation of actigraphy data for sleep duration estimation.     

Actigraphy in the Assessment of Insomnia: A Quantitative Approach

Study Objective:

The lack of quantitative criteria for identifying insomnia using actigraphy represents an unresolved limit for the use of actigraphy in a clinical setting. The current study was conducted to evaluate the most efficient actigraphic parameter in the assessment of insomnia and to suggest preliminary quantitative actigraphic criteria (QAC).

Participants and Measurements:

Performing a retrospective study we recovered 408 actigraphic records from 3 sleep measure databases: 2 regarding insomnia patients (n = 126) and one normal sleepers (n = 282). We compared the 2 samples analyzing the following actigraphic sleep parameters: time in bed (TIB), sleep onset latency (SOL), total sleep time (TST), wake after sleep onset (WASO), sleep efficiency percentage (SE%), number of awakenings longer than 5 minutes (NA > 5) and mean motor activity (MA). Moreover, a linear discriminant function (LDF) was developed to identify and combine the most useful actigraphic sleep parameters to separate insomnia patients from normal sleepers. Using Youden index we calculated the preliminary QAC for each actigraphic sleep parameter and for LDF. Receiver operator characteristic (ROC) curves for classifying the accuracy of QAC were performed.

Results:

All sleep parameters recorded by actigraphy significantly differentiated the 2 groups, except TIB. An LDF analysis showed that the most useful combination of actigraphic sleep parameters to assess insomnia was TST, SOL, and NA > 5, which obtained the best ROC and the best balance between positive and negative predictive values compared to any single actigraphic parameter.

Conclusion:

Actigraphy provided a satisfactory objective measurement of sleep quality in insomnia patients. The combination of TST, SOL, and NA > 5 proved the best way to assess insomnia using actigraphy. Acknowledging that the lack of a technological standard and some methodological limitations prevent us generalizing our results, we recommend additional studies on larger populations using different actigraph models.

Citation:

Natale V; Plazzi G; Martoni M. Actigraphy In The Assessment Of Insomnia: A Quantitative Approach. SLEEP 2009;32(6):767–771.     

Heart rate increment analysis is not effective for sleep-disordered breathing screening in patients with chronic heart failure

Frequency domain analysis of heart rate variation has been suggested as an effective screening tool for sleep-disordered breathing (SDB) in the general population. The aim of this study was to assess this method in patients with chronic congestive heart failure (CHF). We included prospectively 84 patients with stable CHF, left ventricular ejection fraction (LVEF) <45% and sinus rhythm. The patients underwent polygraphy to measure the apnoea/hypopnoea index (AHI) and simultaneous Holter electrocardiogram monitoring to measure the power spectral density of the very low frequency component of the heart rate increment, expressed as the percentage of total power spectral density [% very low frequency increment (%VLFI)]. %VLFI could be determined in 54 patients (mean age, 52.8 ± 12.3 years; LVEF, 33.5 ± 9.8%). SDB defined as AHI ≥15 h⁻¹ was diagnosed in 57.4% of patients. Percent VLFI was not correlated with AHI ( r  =   0.12). Receiver-operating characteristic curves constructed using various AHI cut-offs (5–30 h⁻¹) failed to identify a %VLFI cut-off associated with SDB. The 2.4% VLFI cut-off recommended for the general population of patients with suspected SDB had low specificity (35%) and low positive and negative predictive values (35% and 54%, respectively). Heart rate increment analysis has several limitations in CHF patients and cannot be recommended as an SDB screening tool in the CHF population.     

Sleep Disordered Breathing in Children in a General Population Sample: Prevalence and Risk Factors

Study Objectives:

Assess the prevalence based on clinically meaningful criteria (i.e., blood pressure) and identify risk factors of sleep disordered breathing (SDB) in a representative sample of elementary school children.

Design:

A random sample of the local elementary school children (K-5) were assessed using a two-phased strategy. In phase I a brief questionnaire was completed by a parent of each child in local elementary schools (N = 5,740), with a response rate of 78.5%. In phase II, randomly selected children and their parent spent a night in our sleep laboratory (N = 700) with a response rate of 70.0%.

Setting:

University sleep laboratory

Participants:

Children enrolled in local elementary schools.

Intervention:

None

Measurement & Results:

Each child was assessed with a full polysomnogram and completed a history/physical examination including an electrocardiogram, otolaryngology examination, and pulmonary evaluation. The prevalence of moderate SDB (apnea-hypopnea index ≥ 5) was 1.2%. The independent risk factors included nasal abnormalities and minority associated only with mild (1 < AHI < 5) SDB and snoring and waist circumference associated with all levels of SDB. Tonsil size, based on visual inspection, was not an independent risk factor.

Conclusion:

The prevalence of AHI ≥ 5 was 1.2% in a representative sample of elementary school children. Risk factors for SDB included waist circumference, nasal abnormalities (e.g., chronic sinusitis/rhinitis), and minority. The strong linear relationship between waist circumference and BMI across all degrees of severity of SDB suggests that, as in adults, metabolic factors may be among the most important risk factors for SDB in children.

Citation:

Bixler EO; Vgontzas AN; Lin HM; Liao D; Calhoun S; Vela-Bueno A; Fedok F; Vlasic V. Sleep disordered breathing in children in a general population sample: prevalence and risk factors. SLEEP 2009;32(6):731-736.