Relationship between obstructive sleep apnea and pulmonary hypertension: past, present and future

INTRODUCTION

Obstructive sleep apnea (OSA) is a widely prevalent condition with consequent multiple organ systems complications. There is consensus that OSA is associated with negative effects on pulmonary hemodynamics but whether it contributes to development of clinical pulmonary hypertension (PH) is unclear.

AREAS COVERED

In this review, we (1) highlight previous studies looking into the possible bidirectional association of OSA and PH, focusing on those that explore clinical prognostic implications, (2) explore potential pathophysiology, (3) discuss the new metrics in OSA, (4) describe endo-phenotyping of OSA, (5) recommend possible risk assessment and screening pathways.

EXPERT OPINION

Relying only on symptoms to consider a sleep study in PH patients is a missed opportunity to detect OSA, which, if present and not treated, can worsen outcomes. The potential prognostic role of sleep study metrics such as oxygen desaturation index (ODI), hypoxic burden (HB) and ventilatory burden (VB) in OSA should be studied in prospective trials to identify patients at risk for PH. AHI alone has not provided clarity. In those with PH, we should consider replacing ambulatory overnight pulse oximetry (OPO) with home sleep studies (HST). In PH patients, mild OSA should be sufficient to consider PAP therapy.

Prevalence of Obstructive Sleep Apnea in the Young Adult Population: A Systematic Review

BACKGROUND

The prevalence of obstructive sleep apnea (OSA) is suggested to differ according to different age groups. While its prevalence has been extensively investigated among middle-aged and old individuals, very few studies have summarized its prevalence among young adults. The present study aimed to conduct a systematic review and meta-analysis of OSA prevalence among healthy adults aged 18-30 years in the general population.

METHODS

A search of Embase, Medline, and Web of Science databases for articles reporting the prevalence of OSA among young adults confirmed by objective diagnostic methods was completed by two reviewers. Studies identified and included in the review were summarized qualitatively. Additionally, a meta-analysis of prevalence rates was conducted using a random effects model.

RESULTS

11 articles out of 5898 met the inclusion criteria and were included in the meta-analysis. The diagnostic thresholds, scoring criteria, and the type of used device varied substantially among all the studies. We found that the pooled prevalence of OSA among young adults was 16% (CI 95%, 8-29%, I2 = 92%, τ2 = 1.47).

CONCLUSION

The prevalence of OSA among young adults was found to be ~16%. However, a few factors diverged prevalence between the studies, such as hypopnea definition, AHI threshold, and type of device. Most of the studies included examined healthy volunteers, suggesting that the disease burden may be underestimated. Findings from our review highlight the need to include OSA-related assessment and intervention in the overall health care of young adults. By early detection and offered treatment, further complications related to comorbidities may be omitted.

Comparison of Polysomnography, Single-Channel Electroencephalogram, Fitbit, and Sleep Logs in Patients With Psychiatric Disorders: Cross-Sectional Study

BACKGROUND

Sleep disturbances are core symptoms of psychiatric disorders. Although various sleep measures have been developed to assess sleep patterns and quality of sleep, the concordance of these measures in patients with psychiatric disorders remains relatively elusive.

OBJECTIVE

This study aims to examine the degree of agreement among 3 sleep recording methods and the consistency between subjective and objective sleep measures, with a specific focus on recently developed devices in a population of individuals with psychiatric disorders.

METHODS

We analyzed 62 participants for this cross-sectional study, all having data for polysomnography (PSG), Zmachine, Fitbit, and sleep logs. Participants completed questionnaires on their symptoms and estimated sleep duration the morning after the overnight sleep assessment. The interclass correlation coefficients (ICCs) were calculated to evaluate the consistency between sleep parameters obtained from each instrument. Additionally, Bland-Altman plots were used to visually show differences and limits of agreement for sleep parameters measured by PSG, Zmachine, Fitbit, and sleep logs.

RESULTS

The findings indicated a moderate agreement between PSG and Zmachine data for total sleep time (ICC=0.46; P<.001), wake after sleep onset (ICC=0.39; P=.002), and sleep efficiency (ICC=0.40; P=.006). In contrast, Fitbit demonstrated notable disagreement with PSG (total sleep time: ICC=0.08; wake after sleep onset: ICC=0.18; sleep efficiency: ICC=0.10) and exhibited particularly large discrepancies from the sleep logs (total sleep time: ICC=-0.01; wake after sleep onset: ICC=0.05; sleep efficiency: ICC=-0.02). Furthermore, subjective and objective concordance among PSG, Zmachine, and sleep logs appeared to be influenced by the severity of the depressive symptoms and obstructive sleep apnea, while these associations were not observed between the Fitbit and other sleep instruments.

CONCLUSIONS

Our study results suggest that Fitbit accuracy is reduced in the presence of comorbid clinical symptoms. Although user-friendly, Fitbit has limitations that should be considered when assessing sleep in patients with psychiatric disorders.

Congenital myasthenic syndromes: a retrospective natural history study of respiratory outcomes in a single centre

Respiratory problems are a major cause of morbidity and mortality in patients with congenital myasthenic syndromes, a rare heterogeneous group of neuromuscular disorders caused by genetic defects impacting the structure and function of the neuromuscular junction. Recurrent, life-threatening episodic apnoea in early infancy and childhood and progressive respiratory failure requiring ventilation are features of certain genotypes of congenital myasthenic syndromes. Robb et al. published empirical guidance on respiratory management of the congenital myasthenic syndromes, but other than this workshop report, there are little published longitudinal natural history data on respiratory outcomes of these disorders. We report a retrospective, single-centre study on respiratory outcomes in a cohort of 40 well characterized genetically confirmed cases of congenital myasthenic syndromes, including 10 distinct subtypes (DOK7, COLQ, RAPSN, CHAT, CHRNA1, CHRNG, COL13A1, CHRNE, CHRNE fast channel syndrome and CHRNA1 slow channel syndrome), with many followed up over 20 years in our centre. A quantitative and longitudinal analysis of key spirometry and sleep study parameters, as well as a description of historical hospital admissions for respiratory decompensation, provides a snapshot of the respiratory trajectory of congenital myasthenic syndrome patients based on genotype.

Reasons and predictors for early termination of pediatric polysomnography: one children's hospital's experience

STUDY OBJECTIVES

We sought to identify reasons for early polysomnography termination in pediatric patients.

METHODS

We retrospectively reviewed all studies conducted at the Pediatric Sleep Center at UT Southwestern Medical Center from January 1, 2017, through December 31, 2019, that were terminated before study completion. We investigated reasons for early termination and gathered characteristics such as age, sex, presence of neurocognitive impairment, payor status, seasonal variability, and testing site location.

RESULTS

There were 137 patients who terminated their studies before completion, comprising 1.05% of all patients who arrived for their scheduled polysomnographies during that time frame. The 3 main categories of reasons were equipment intolerance (47%), acute illness (33%), and parental refusal (20%). Parental refusal reasons included the patient's becoming combative, a lack of specialized equipment, patient's inability to fall asleep, forgetting the patient's nighttime medications, and the parent's inability to stay the night. Males represented a greater proportion of those who terminated due to intolerance of equipment (75%). Patients who terminated early due to equipment intolerance consisted of more neurologically impaired patients compared with those who terminated due to acute illness (56% vs 24%). Termination due to acute illness occurred more during the wintertime (44%) than in the summer (7%). In those who terminated due to parental refusal, there was a greater proportion of children under 6 years of age (75%).

CONCLUSIONS

Determining factors that are associated with early polysomnography termination is an important step to help identify at-risk groups and implement strategies to improve study completion.

CITATION

Luong S, Culp M, McCreary M, Wani A, Caraballo M. Reasons and predictors for early termination of pediatric polysomnography: one children's hospital's experience. J Clin Sleep Med. 2023;19(10):1711-1716.

Assessing the Feasibility of Replacing Subjective Questionnaire-Based Sleep Measurement with an Objective Approach Using a Smartwatch

In order to ensure sufficient recovery of the human body and brain, healthy sleep is indispensable. For this purpose, appropriate therapy should be initiated at an early stage in the case of sleep disorders. For some sleep disorders (e.g., insomnia), a sleep diary is essential for diagnosis and therapy monitoring. However, subjective measurement with a sleep diary has several disadvantages, requiring regular action from the user and leading to decreased comfort and potential data loss. To automate sleep monitoring and increase user comfort, one could consider replacing a sleep diary with an automatic measurement, such as a smartwatch, which would not disturb sleep. To obtain accurate results on the evaluation of the possibility of such a replacement, a field study was conducted with a total of 166 overnight recordings, followed by an analysis of the results. In this evaluation, objective sleep measurement with a Samsung Galaxy Watch 4 was compared to a subjective approach with a sleep diary, which is a standard method in sleep medicine. The focus was on comparing four relevant sleep characteristics: falling asleep time, waking up time, total sleep time (TST), and sleep efficiency (SE). After evaluating the results, it was concluded that a smartwatch could replace subjective measurement to determine falling asleep and waking up time, considering some level of inaccuracy. In the case of SE, substitution was also proved to be possible. However, some individual recordings showed a higher discrepancy in results between the two approaches. For its part, the evaluation of the TST measurement currently does not allow us to recommend substituting the measurement method for this sleep parameter. The appropriateness of replacing sleep diary measurement with a smartwatch depends on the acceptable levels of discrepancy. We propose four levels of similarity of results, defining ranges of absolute differences between objective and subjective measurements. By considering the values in the provided table and knowing the required accuracy, it is possible to determine the suitability of substitution in each individual case. The introduction of a "similarity level" parameter increases the adaptability and reusability of study findings in individual practical cases.

Reliability of parental reporting of child snoring in children referred for obstructive sleep apnea

Despite the high number of studies based on subjective reports of snoring, self-reported snoring has hardly been validated at all. As there is no "gold-standard" for objective snoring measurements, studies must evaluate whether the presence of snoring based on parental judgement is linked to objective measurements of nasal and/or pharyngeal obstruction in children referred for obstructive sleep apnea. A total of 146 children (median age 11 years) underwent polysomnography (with snoring recording using nasal cannula signal), acoustic rhinometry and pharyngometry, while their parents filled out the Spruyt-Gozal questionnaire assessing both frequency and loudness of subjective snoring. Three categories were further differentiated (null, low and high) for both frequency and loudness. The apnea-hypopnea index was significantly different in the three groups for both frequency (p = 0.04) and loudness (p = 0.01) of subjective snoring. Children in the low or high groups (frequency or loudness), compared with those in the null group, experienced a decline in both pharyngeal (sitting and supine positions) and nasopharyngeal (supine position) volumes (frequency, pharynx sitting: p = 0.03; supine: 0.005 and nasopharynx: p = 0.002; loudness, p = 0.03; p = 0.007 and p = 0.03; three group comparisons). Objective snoring frequency during the night obtained with cannula was weakly related to loudness of subjective snoring but not to subjective snoring frequency during the week, and was biased by nasal obstruction. In conclusion, our study showed that parental assessment of snoring is related to a reduction in both pharyngeal and nasopharyngeal volumes in snorers, arguing for the adequacy of their evaluation of both snoring frequency and loudness.

Moving toward standardization: physician reporting of sleep studies

Detailed primary data collected from sleep studies should lead to specific and clear reports with evidence-based clinical recommendations that, when introduced by sleep medicine specialists, create a window of opportunity to support our non-sleep medicine referring teams and to engage patients and caregivers in their care as recipients of the reports. This is how sleep study reporting differs from other test reports; currently, there is wide variation in how the data collected are presented and summarized. The goal of this document is to offer recommendations for structured reporting of sleep studies. We offer a practical, complete, and relevant document and a structure that can be implemented across sleep centers nationwide and does not burden the interpreter. We anticipate some readers will opine that some of the content is beyond the scope of what the interpreter physician needs to include, while others will propose missing data that they feel should have been included. We feel that the flexibility of the proposal accommodates for this and allows for a "first step" toward standardization of physician reporting of sleep studies. High-quality structured reporting of sleep studies is becoming ever more important for patient care, benefiting patients, caregivers, clinicians, durable medical equipment companies, and payers.

CITATION

Lastra AC, Ingram D, Park J, et al. Moving toward standardization: physician reporting of sleep studies. J Clin Sleep Med. 2023;19(3):595-603.

Expert Consensus Statement: Management of Pediatric Persistent Obstructive Sleep Apnea After Adenotonsillectomy

OBJECTIVE

To develop an expert consensus statement regarding persistent pediatric obstructive sleep apnea (OSA) focused on quality improvement and clarification of controversies. Persistent OSA was defined as OSA after adenotonsillectomy or OSA after tonsillectomy when adenoids are not enlarged.

METHODS

An expert panel of clinicians, nominated by stakeholder organizations, used the published consensus statement methodology from the American Academy of Otolaryngology-Head and Neck Surgery to develop statements for a target population of children aged 2-18 years. A medical librarian systematically searched the literature used as a basis for the clinical statements. A modified Delphi method was used to distill expert opinion and compose statements that met a standardized definition of consensus. Duplicate statements were combined prior to the final Delphi survey.

RESULTS

After 3 iterative Delphi surveys, 34 statements met the criteria for consensus, while 18 statements did not. The clinical statements were grouped into 7 categories: general, patient assessment, management of patients with obesity, medical management, drug-induced sleep endoscopy, surgical management, and postoperative care.

CONCLUSION

The panel reached a consensus for 34 statements related to the assessment, management and postoperative care of children with persistent OSA. These statements can be used to establish care algorithms, improve clinical care, and identify areas that would benefit from future research.

Prevalence and Correlates of Sleep Disorders Among Pediatric Inpatients in a Tertiary Pediatric Hospital

Background It is possible to define sleep disorders as any disturbance in sleep timing, quality, or quantity that results in daytime distress and impairment in functioning that, in turn, affects the baseline functional status of an individual. Our study aimed to describe how sleep disorders might affect pediatric inpatients at King Abdulaziz University Hospital (KAUH) as well as estimate their prevalence (2021-2022). We assessed the sleep habits using questionnaires and analyzed and combined these data to create rankings to compare the different issues affecting sleep habits in pediatric patients. Methodology Two scoring systems were used in this study, namely (a) the Children's Sleep Habits Questionnaire (CSHQ) and (b) the Pediatric Sleep Questionnaire. Analyses of the data were conducted using SPSS version 23 (IBM Corp., Armonk, NY, USA) and GraphPad Prism version 8 (GraphPad Software, Inc., San Diego, CA, USA). Results The prevalence of sleep disorders and their correlations were evaluated among 98 pediatric inpatients at KAUH, Saudi Arabia, between 2021 and 2022. The average duration of hospital stay was 11.97 ± 11.0 days (N = 78), and the average number of previous admissions was 2.85 ± 3.7 (N = 93). Conclusions According to the sleep behavior domain of the CSHQ, most children woke up sweating, screaming, and inconsolable during the night. Furthermore, bedtime resistance and sleep anxiety were the most prevalent sleep disturbances observed in the study population.

Residual OSA in Down syndrome: does body position matter?

STUDY OBJECTIVES

To examine children with Down syndrome with residual obstructive sleep apnea (OSA) to determine if they are more likely to have positional OSA.

METHODS

A retrospective chart review of children with Down syndrome who underwent adenotonsillectomy at a single tertiary children's hospital was conducted. Children with Down syndrome who had a postoperative polysomnogram with obstructive apnea-hypopnea index (OAHI) > 1 event/h, following adenotonsillectomy with at least 60 minutes of total sleep time were included. Patients were categorized as mixed sleep (presence of ≥ 30 minutes of both nonsupine and supine sleep), nonsupine sleep, and supine sleep. Positional OSA was defined as an overall OAHI > 1 event/h and a supine OAHI to nonsupine OAHI ratio of ≥ 2. Group differences are tested via Kruskal-Wallis test for continuous variables and Fisher's exact tests for categorical.

RESULTS

There were 165 children with Down syndrome who met inclusion criteria, of which 130 individuals had mixed sleep. Patients who predominately slept supine had a greater OAHI than mixed and nonsupine sleep (P = .002). Sixty (46%) of the mixed-sleep individuals had positional OSA, of which 29 (48%) had moderate/severe OSA. Sleeping off their backs converted 14 (48%) of these 29 children from moderate/severe OSA to mild OSA.

CONCLUSIONS

Sleep physicians and otolaryngologists should be cognizant that the OAHI may be an underestimate if it does not include supine sleep. Positional therapy is a potential treatment option for children with residual OSA following adenotonsillectomy and warrants further investigation.

CITATION

Lackey TG, Tholen K, Pickett K, Friedman N. Residual OSA in Down syndrome: does body position matter? J Clin Sleep Med. 2023;19(1):171-177.

Automated Analysis of Sleep Study Parameters Using Signal Processing and Artificial Intelligence

An automated sleep stage categorization can readily face noise-contaminated EEG recordings, just as other signal processing applications. Therefore, the denoising of the contaminated signals is inevitable to ensure a reliable analysis of the EEG signals. In this research work, an empirical mode decomposition is used in combination with stacked autoencoders to conduct automatic sleep stage classification with reliable analytical performance. Due to the decomposition of the composite signal into several intrinsic mode functions, empirical mode decomposition offers an effective solution for denoising non-stationary signals such as EEG. Preliminary results showed that through these intrinsic modes, a signal with a high signal-to-noise ratio can be obtained, which can be used for further analysis with confidence. Therefore, later, when statistical features were extracted from the denoised signals and were classified using stacked autoencoders, improved results were obtained for Stage 1, Stage 2, Stage 3, Stage 4, and REM stage EEG signals using this combination.

Migraine may disturb sleep perception during sleep onset: a retrospective data analysis

STUDY OBJECTIVES

As sleep latency is an important factor in the diagnosis of many disorders, it is important to know whether the patient's self-reported evaluation of sleep latency corresponds with an objectively measured evaluation. Some studies indicate that patients usually overestimate their sleep latency. We sought to determine how comorbidities affect the patient's ability to assess their sleep latency.

METHODS

This was a retrospective study of 240 patients who had a polysomnography recorded at our sleep unit or at home in 2017-2020. Data on comorbidities were collected from hospital records.

RESULTS

Mean objective sleep latency (29.5 minutes, standard deviation [SD] 35.5) was significantly lower than self-reported sleep (37.4 minutes, SD 41.6) (P < .001). The patients who overestimated their sleep latency had higher mean apnea-hypopnea index (18.8 events/h, SD 21.6, vs 13.4 events/h, SD 12.8; P = .04) and higher mean sleep efficiency (81.7%, SD 13.6%, vs 75.2%, SD 13.9%; P = .004) than those who underestimated their sleep latency. There were significantly more patients with migraine in the overestimation group than in the underestimation group (20/159 patients vs 3/81 patients; P = .035). This difference was not observed in patients with headache without migraine (P = 1.000).

CONCLUSIONS

We hypothesize that migraine is markedly associated with overestimation of sleep latency. This overestimation was not observed in patients with other headache types. Further studies are needed to explore the relation between migraine and sleep onset misperception.

CITATION

Rantanen O, Hollmen M, Bachour A. Migraine may disturb sleep perception during sleep onset: a retrospective data analysis. J Clin Sleep Med. 2022;18(9):2113-2117.

Combination therapy of high-flow nasal cannula and upper body elevation for postoperative sleep disordered breathing; randomized cross-over trial

BACKGROUND

Low acceptance rate of continuous positive airway pressure therapy in postoperative patients with untreated obstructive sleep apnea (OSA) indicates the necessity for development of an alternative postoperative airway management strategy. We considered whether the combination of high-flow nasal cannula and upper body elevation could improve postoperative OSA.

METHODS

This non-blinded randomized crossover study performed at a single university hospital investigated the effect on a modified apnea hypopnea index, based exclusively on the airflow signal without arterial oxygen saturation criteria (flow-based apnea hypopnea index, primary outcome), of high-flow nasal cannula (20 liter.minute-1 with 40% oxygen concentration) with and without upper body elevation in patients with moderate to severe OSA. Preoperative sleep studies were performed at home (control, no head-of-bed elevation) and in hospital (30-degree head-of-bed elevation). On the first and second postoperative nights, high-flow nasal cannula was applied with or without 30-degree head-of-bed elevation, assigned in random order to 23 eligible participants.

RESULTS

Twenty-two out of the 23 (96%) accepted high-flow nasal cannula. Four participants resigned from the study. Control flow-based apnea hypopnea index (mean±SD: 59.6 ± 12.0 events.hour-1, n=19) was reduced by 14.7 (95% CI: 5.5 to 30.0) events.hour-1 with head-of-bed elevation alone (p=0.002), 10.9 (1.2 to 20.6) events.hour-1 with high-flow nasal cannula alone (p=0.028), and 22.5 (13.1 to 31.9) events.hour-1 with combined head-of-bed elevation and high-flow nasal cannula (p<0.001). Compared to sole high-flow nasal cannula, additional intervention with head-of-bed elevation significantly decreased flow-based apnea hypopnea index by 11.5 events.hour-1 (1.7 to 21.4) (p=0.022). High-flow nasal cannula, alone or in combination with head-of-bed elevation also improved overnight oxygenation. No harmful events were observed.

CONCLUSION

The combination of high-flow nasal cannula and upper body elevation reduced OSA severity and nocturnal hypoxemia, suggesting a role for it as an alternate postoperative airway management strategy.

Association between sleep disordered breathing in early pregnancy and glucose metabolism

STUDY OBJECTIVES

To examine the association between maternal sleep disordered breathing (SDB) and glucose metabolism in early gestation.

METHODS

Women with body mass index (BMI) ≥27 kg/m2 and singleton pregnancies underwent in-home sleep study (HSAT) and homeostatic model assessment (HOMA) in early pregnancy. Insulin resistance (HOMA-IR) and β-cell function (HOMA %B) were derived. Exclusion criteria included pregestational diabetes, use of continuous positive airway pressure and chronic steroid therapy. We performed linear regression analyses to evaluate the association between continuous measures of SDB (respiratory event index (REI), and oxygen desaturation index (ODI)) and glucose metabolism parameters (HOMA-IR and HOMA %B). Analyses were adjusted for a set of a priori selected variables which included gestational age, maternal age, BMI, ethnicity, race, and parity.

RESULTS

One hundred and ninety-two pregnant women with median (interquartile range) BMI of 35.14 (8.30) kg/m2 underwent HSAT and HOMA assessment at 11.14 (3) and 15.35 (4.14) gestational weeks, respectively. REI and ODI, as continuous values, were associated with HOMA-IR after adjusting for covariates. OSA (obstructive sleep apnea) diagnosis (REI > 5 events per hour) was not associated with HOMA-IR after adjusting for BMI (p ≥ 0.05). None of the parameters were associated with HOMA %B (p > 0.07).

CONCLUSIONS

SDB and insulin resistance are associated in early pregnancy, with a dose response association between respiratory event index severity and insulin resistance. Further studies are needed to establish if pregnant women with overweight and obesity may benefit from early SDB screening to improve glucose metabolic outcome. Clinical trials: NCT02412696, Positive Airway Pressure, Sleep Apnea, and the Placenta (PAP-SAP) https://clinicaltrials.gov/ct2/show/NCT02412696?term=Bourjeily&draw=2&rank=2 and NCT02917876, Predictors of De-novo Development of Obstructive Sleep Apnea in Pregnancy (Predictors) https://clinicaltrials.gov/ct2/show/NCT02917876?term=Bourjeily&draw=2&rank=1.

Literature Cases Summarized Based on Their Polysomnographic Findings in Rett Syndrome

Rett syndrome (RTT) is a severe and rare neurodevelopmental disorder affecting mostly girls. In RTT, an impaired sleep pattern is a supportive criterion for the diagnosis, yet little is known regarding the sleep structure and sleep respiratory events. Aiming to delineate sleep by aggregating RTT case (series) data from published polysomnographic studies, seventy-four RTT cases were collected from eleven studies up until 6 February 2022 (PROSPERO: CRD 42020198099). We compared the polysomnographic data within RTT stratifications and to a typically developing population. MECP2 cases demonstrated shortened total sleep time (TST) with increased stage N3 and decreased REM sleep. In cases with CDKL5 mutations, TST was longer and they spent more time in stage N1 but less in stage N3 than those cases affected by MECP2 mutations and a typically developing population. Sleep-disordered breathing was confirmed by the abnormal apnea/hypopnea index of 11.92 ± 23.67/h TST in these aggregated cases. No association of sleep structure with chronological age was found. In RTT, the sleep macrostructure of MECP2 versus CDKL5 cases showed differences, particularly regarding sleep stage N3. A severe REM sleep propensity reduction was found. Aberrant sleep cycling, possibly characterized by a poor REM ‘on switch’ and preponderance in slow and high-voltage sleep, is proposed.

Polysomnographic analysis of maternal sleep position and its relationship to pregnancy complications and sleep-disordered breathing

Links between supine "going to sleep" position and stillbirth risk have led to campaigns regarding safe maternal sleep position. This study profiles the distribution of sleep positions overnight and relationships to sleep onset position during pregnancy, and the relationships between supine sleep, sleep-disordered breathing (SDB), and pregnancy outcomes. Data from three prospective cohort studies evaluating SDB in healthy and complicated pregnancies were pooled. All participants underwent one night of polysomnography in late pregnancy and birth outcome data were collected. 187 women underwent polysomnography at a median gestation of 34 weeks'. The left lateral position was preferred for falling asleep (52%) compared to supine (14%), but sleep onset position was the dominant sleep position overnight in only half (54%) of women. The median percentage of sleep time in the supine position was 24.2%; women who fell asleep supine spent more time supine overnight compared to those who began non-supine (48.0% (30.0,65.9) vs. 22.6% (5.7,32.2), p < .001). Women with growth-restricted fetuses were more likely to fall asleep supine than those with well-grown fetuses (36.6% vs. 7.5%, p < .001). Positional SDB was observed in 46% of those with an RDI ≥ 5. Sleep onset position was the dominant position overnight for half of the sample, suggesting that sleep onset position is not always a reliable indicator of body position overnight. Supine sleep was related to fetal growth restriction and birthweight at delivery, though causality cannot be inferred. It is critical that we pursue research into verifying the important relationship between supine sleep and increased stillbirth risk, and the mechanisms behind it.

A Randomized Controlled Trial of Sleep Study Surveillance with Targeted APAP Therapy for Obstructive Sleep Apnea in Pregnancy

OBJECTIVE(S)

To determine effects of targeted autoregulated positive airway pressure (APAP) in women at risk for obstructive sleep apnea (OSA) on adverse pregnancy outcomes (APOs), cost, and natural history of OSA.

STUDY DESIGN

Pregnant women at high risk for OSA were randomized to a sleep study screening group with possible initiation of APAP compared to women not screened for OSA, receiving standard obstetric care (control). Women in the sleep study screened group received a sleep study at two points during pregnancy, early (6-16 weeks) and late (27-33 weeks), with initiation of APAP therapy if their apnea hypopnea index (AHI) indicated ≥ 5 events per hour. Women of both groups had a sleep study 3 months postpartum. The primary outcome was effect on APO, a composite of hypertension, preterm birth, low birthweight, stillbirth and diabetes. Secondary outcomes included OSA severity and hospital costs.

RESULTS

Among 193 women randomized (100 sleep study screened group; 93 control group; 6 lost to follow up), there were no significant differences in composite APO (46.4% screened vs. 43.3% control, p=0.77), hypertension (23.7% screened vs. 32% control, p=0.25), preterm birth (13.4% screened vs. 10% control, p=0.5), low birthweight (5.2% screened vs. 6.7% control, p=0.76), stillbirth (1% screened vs. 0% control, p=1), gestational diabetes (19.6% screened vs. 13.3% control, p=0.33), or mean cost ($12,185 screened vs. $12,607 control). The AHI increased over the course of pregnancy, peaking at 3 months postpartum (p<.001). There were 24 (25.8%) subjects who had a new diagnosis of OSA, with 6 in whom APAP was prescribed. APAP compliance rates were poor with usage rates ranging from 2% (1 of 64 days) to 43% (6 of 14 days).

CONCLUSION

Targeted APAP therapy for OSA in a sleep study screened high risk pregnancy group did not decrease composite adverse pregnancy outcomes or hospital costs compared to a group that received no OSA screening. However, a small sample size, low APAP prescription rates and poor compliance resulted in difficulty in drawing a definitive conclusion. The prevalence and severity of OSA worsened over the course of pregnancy, with the highest rates detected in the postpartum period. Large, multi-center clinical trials that are adequately powered are needed.

Neurophysiological profiles of responders and non-responders to hypoglossal nerve stimulation: a single institution study

STUDY OBJECTIVES

Hypoglossal nerve stimulation (HGNS) is an effective alternative treatment for obstructive sleep apnea (OSA) that acts by opening the airway via selective stimulation of nerve fibers that innervate tongue muscles that protrude (genioglossus) and stiffen the tongue (transverse and vertical) while avoiding nerve fibers that innervate tongue muscles that retract the tongue (styloglossus and hyoglossus). There remains a subset of post-operative patients who fail to adequately respond to HGNS, in some cases due to simultaneous mixed activation of muscles that protrude and retract the tongue. This study aims to characterize the relationship between neurophysiological data from individual tongue muscle activation during intraoperative electromyographic (EMG) recordings and post-operative AHI responses to HGNS..

METHODS

A single institution review of 46 patients undergoing unilateral HGNS implantation for OSA. Patients were separated into responders and non-responders through comparison of pre and postoperative AHI. Neurophysiological data included EMG responses of the genioglossus, styloglossus/hyoglossus, intrinsic/vertical, and hyoglossus (neck) muscles to intraoperative stimulation using unipolar (--- and o-o) and bipolar (+-+) settings.

RESULTS

The overall treatment success rate was 61% as determined by a post-operative AHI <20 events/hr with a greater than 50% AHI reduction. We observed no statistically significant relationships between treatment response and individual muscle responses. However, we did note that increasing BMI was correlated with worse post-operative responses.

CONCLUSIONS

Although we noted a significant sub-group of clinical non-responders to HGNS post-operatively, these patients were not found to exhibit significant inclusion of tongue retractors intraoperatively on neurophysiological analysis. Further research is needed to delineate additional phenotypic factors that may contribute to HGNS treatment responses.

Nocturnal hypoxemia measured by polysomnogram is associated with acute chest syndrome in pediatric sickle cell disease

STUDY OBJECTIVES

Nocturnal hypoxemia is associated with increased risk of sickle cell disease (SCD) complications. The association of nighttime hypoxemia and acute chest syndrome (ACS) in children with SCD has yet to be determined.

METHODS

This is a retrospective study of children with SCD who underwent polysomnography at a SCD center. Univariate logistic regression was used to assess the association between nocturnal hypoxemia and ACS admissions. Multivariate logistic regression was performed to verify the effects of different clinical covariates on ACS. Secondary analysis comparing patients with one vs multiple ACS admissions was performed.

RESULTS

One hundred ten individuals with SCD who completed their polysomnogram (mean age of 9.4 years) were identified. Fifty-nine (54%) had a history of at least one episode of ACS admission (mean age of 4.1 years), including 40 with multiple episodes. The percentage of total sleep time with O₂ saturation < 90% was greater in the ACS group (P < .05). Similarly, mean nocturnal O₂ saturation was lower in the ACS group (P < .0005). Mean nocturnal O₂ saturation of < 97.3% and the percentage of total sleep time with O₂ saturation < 90% higher than 2.7% were associated with ACS. There was no difference in nocturnal hypoxemia between patients with single and multiple ACS admissions.

CONCLUSIONS

Nocturnal hypoxemia later in life is associated with previous ACS admissions in children with SCD. This can increase the yield of interpreting polysomnograms in this vulnerable population. Prospective studies are needed to determine the temporal relations of nocturnal hypoxemia and ACS, which may identify a modifiable risk for ACS.

Persistent OSA in obese children: does body position matter?

STUDY OBJECTIVES

The objective of this study was to determine if positional therapy is a viable treatment alternative for obese children with persistent obstructive sleep apnea (OSA).

METHODS

A retrospective review was performed of children who underwent an adenotonsillectomy for OSA from 2014 to 2017. Children were included if they had a body mass index ≥ 95th percentile and underwent a postoperative polysomnogram. Subjects fell into one of three categories: mixed sleep (the presence of ≥ 30 minutes of both nonsupine and supine sleep), nonsupine sleep, and supine sleep. Cure was defined as an OSA/apnea-hypopnea index of < 1 events/h. Paired t tests were used to assess the differences, and a linear model adjusting for obesity class, age at procedure, and sex was performed to assess the differences between nonsupine and supine sleep.

RESULTS

There were 154 children who met the inclusion criteria. Using a paired t test, supine sleep position had a significantly higher average OSA/apnea-hypopnea index (7.9 events) compared with nonsupine (OSA/apnea-hypopnea index of 4.1); P value was < .01 for the 60 children with mixed sleep. Forty-three children had predominantly nonsupine sleep and 33 predominantly supine sleep, and a McNemar's test comparing these children showed that those sleeping in the nonsupine position were significantly more likely to be cured than those in the supine position (P < .001).

CONCLUSIONS

Sleep physicians and otolaryngologists should be cognizant of positional treatment when consulting with families and note that the postoperative polysomnography may be inaccurate if it does not include supine sleep. Positional therapy as a potential treatment option for obese children with persistent OSA after adenotonsillectomy warrants further investigation.

Primary care provider evaluation and management of insomnia

STUDY OBJECTIVES

To evaluate the type and extent of information collected from patients with insomnia during their first office encounter for insomnia and the prescribing therapies of primary care providers during this initial encounter.

METHODS

This study was a retrospective chart review of randomly selected patients who had a primary care provider office visit at any clinic affiliated with a university medical system between March 1, 2013, and March 1, 2016. Demographic and clinical information was abstracted for analysis.

RESULTS

Our sample (n = 200) was primarily female (63.5%), White (69%), middle-aged (ages 44.6 ± 15.1 years) adults. Most (68.5%) encounter notes did not have significant information related to insomnia risk factors and symptoms (< 50% of the notes). When examining comorbidities, we found that younger patients (<45 years old) were more likely to have anxiety linked to insomnia (P = .025), whereas older patients (≥45) were less likely to have any identified comorbidities associated with insomnia (P = .009). Only 5.0% of patients with insomnia were referred for cognitive-behavioral therapy for insomnia, whereas 51.5% of patients were prescribed sleep medications. The younger cohort was statistically more likely to receive sleep hygiene or cognitive-behavioral therapy for insomnia as a treatment option in comparison to the older cohort (P = .01 and P = .04, respectively).

CONCLUSIONS

Progress notes from primary care providers tend to have a paucity of information on insomnia symptoms and related comorbidities. Medications are often prescribed as the first-line treatment for insomnia. Cognitive-behavioral therapy for insomnia remains underutilized despite robust evidence suggesting that cognitive-behavioral therapy for insomnia is a safe and effective treatment for insomnia.

Night-to-night variability in obstructive sleep apnea using peripheral arterial tonometry: a case for multiple night testing

STUDY OBJECTIVES

Night-to-night variability of obstructive sleep apnea severity (OSA) is considerable and may depend on the diagnostic modality used. We investigated the night-to-night variability using peripheral arterial tonometry (PAT).

METHODS

Home sleep apnea testing was performed in 51 patients during three consecutive nights using PAT. Patients referred to our sleep clinic were screened and prospectively recruited for this study. All recordings were automatically and manually scored according to the PAT scoring guidelines.

RESULTS

No systematic differences in pAHI were found between the nights. The night-to-night variability was comparable between manually and automatically scored data. PAT-derived apnea-hypopnea index (pAHI) varied in 35% of patients more than 10/h between the nights. The OSA severity of 24% of patients was misclassified when using one night compared to the average of all nights. On average, pAHI varied by 57% from night-to-night. The variability of pAHI could partially be explained by the variability of time spent in the supine position with more time supine leading to a higher pAHI. On measuring a subsequent night, 12-14% of patients spontaneously fulfilled the commonly accepted criteria for treatment success without any intervention.

CONCLUSIONS

With repeated recordings of PAT, we found no first night effect. However, there is considerable night-to-night variability similar to values found for polysomnography, which can partially be explained by the variability of time spent in the supine position. OSA severity was frequently misclassified due to the night-to-night variability. Our findings make a strong case for multiple testing in the diagnostic work-up of OSA patients.

Retrospective analysis of inpatient polysomnogram characteristics and discharge outcomes in infants with bronchopulmonary dysplasia requiring home oxygen therapy

RATIONALE

Little is known about the polysomnogram (PSG) characteristics in infants with bronchopulmonary dysplasia (BPD), especially severe BPD, who do not need home ventilatory support but are at increased risk for chronic hypoxia and are vulnerable to its effects.

OBJECTIVE

This study aims to assess PSG characteristics and change in discharge outcomes in premature infants with BPD who required oxygen therapy at discharge.

METHODS

This is a retrospective chart review of premature infants with BPD who were admitted to a quaternary newborn and infant intensive care unit from January 1, 2012 to December 31, 2015 and who underwent polysomnography before discharge.

MEASUREMENTS AND MAIN RESULTS

Data from 127 patients were analyzed. The median gestational age of our patients was 26 weeks and 1 day (interquartile range [IQR]: 24.71, 28.86). The majority of the patients had moderate-to-severe BPD. The median obstructive apnea-hypopnea index was 5.3 events/h (IQR: 2.2, 10.1). The median oxygen desaturation index was 15.7 events/h (IQR: 4.7, 35). Nadir oxygen saturation measured by pulse oximeter was 81% (IQR: 76-86) and the arousal/awakening index was 21.9 (IQR: 13.3-30.9). No statistically significant difference was noted between severe and nonsevere BPD groups for PSG characteristics. However, average end-tidal CO₂ was significantly higher in the severe BPD group (p = .0438). Infants in the severe BPD group were intubated longer than infants with nonsevere BPD (p = .0082). The corrected gestational age (CGA) at the time of discharge (CGA-PSG) and PSG (CGA-DC) was higher in severe BPD patients but not statistically different. The majority of premature infants who underwent a PSG were discharged home with oxygen, and 69% required a titration of their level of support based on results from the PSG.

CONCLUSION

Our results highlight the presence of abnormal PSG characteristics in BPD patients, as early as 43 weeks CGA. These findings have not been previously described in this patient population prior to initial discharge from the hospital. A severe BPD phenotype tends to be associated with higher respiratory morbidity compared with a nonsevere BPD phenotype for the comparable CGA. PSG, when available, may be helpful for individualizing and streamlining treatment in preparation for discharge home and mitigating the effects of intermittent hypoxic episodes.

Demographic and Clinical Characteristics Associated With Adherence to Guideline-Based Polysomnography in Children With Down Syndrome

OBJECTIVES

To compare the demographic and clinical characteristics of children with Down syndrome who did and did not receive polysomnography to evaluate for obstructive sleep apnea after publication of the American Academy of Pediatrics' guidelines recommending universal screening by age 4 years.

STUDY DESIGN

Retrospective cohort study.

SETTING

Single tertiary pediatric hospital.

METHODS

Review was conducted of children with Down syndrome born between 2007 and 2012. Children who obtained polysomnography were compared with children who did not, regarding demographic data, socioeconomic status, and comorbidities.

RESULTS

We included 460 children with Down syndrome; 273 (59.3%) received at least 1 polysomnogram, with a median age of 3.6 years (range, 0.1-8.9 years). There was no difference in the distribution of sex, insurance status, or socioeconomic status between children who received polysomnography and those who did not. There was a significant difference in race distribution (P = .0004) and distance from home to the medical center (P < .0001) between groups. Among multiple medical comorbidities, only children with a history of hypothyroidism (P = .003) or pulmonary aspiration (P = .01) were significantly more likely to have obtained polysomnography.

CONCLUSIONS

Overall, 60% of children with Down syndrome obtained a polysomnogram. There was no difference between groups by payer status or socioeconomic status. A significant difference in race distribution was noted. Proximity to the medical center and increased medical need appear to be associated with increased likelihood of obtaining a polysomnogram. This study illustrates the need for improvement initiatives to increase the proportion of patients receiving guideline-based screening.

How to interpret polysomnography

A 5-year-old child presents to a paediatric clinic with their parents because of concerns about snoring, which is loud, every night and associated with respiratory pauses. This has been present for 6 months. Can clinical evaluation diagnose sleep-disordered breathing in children or are further investigations required? Should further investigations include oximetry or polysomnography? If a polysomnogram is performed, how are the results interpreted? In this paper we describe the indications for polysomnography, outline the parameters measured and decode a clinical polysomnography report.

Clinically Asymptomatic Sleep-Disordered Breathing in Infants with Single-Ventricle Physiology

OBJECTIVES

To assess clinically asymptomatic infants with single-ventricle physiology (SVP) for sleep-disordered breathing (SDB) in the supine and car seat positions using polysomnography. Polysomnography results also were compared with results of a standard Car Seat Challenge to measure the dependability of the standard Car Seat Challenge.

STUDY DESIGN

This was an observational study of 15 infants with SVP. Polysomnography data included Obstructive Index, Central Index, Arousal Index, Apnea Hypopnea Index, and sleep efficiency. Polysomnography heart rate and oxygen saturation data were used to compare polysomnography with the standard Car Seat Challenge.

RESULTS

Polysomnography demonstrated that all 15 infants had SDB and 14 had obstructive sleep apnea (Obstructive Index ≥1/hour) in both the supine and car seat positions. Infants with SVP had a statistically significant greater median Obstructive Index in the car seat compared with supine position (6.3 vs 4.2; P = .03), and median spontaneous Arousal Index was greater in the supine position compared with the car seat (20.4 vs 15.2; P = .01). Comparison of polysomnography to standard Car Seat Challenge results demonstrated 5 of 15 (33%) of infants with SVP with abnormal Obstructive Index by polysomnography would have passed a standard Car Seat Challenge.

CONCLUSIONS

Infants with SVP without clinical symptoms of SDB may be at high risk for SDB that appears worse in the car seat position. The standard Car Seat Challenge is not dependable in the identification of infants with SVP and SDB. Further studies are warranted to further delineate its potential impact of SDB on the clinical outcomes of infants with SVP.

Clinical Characteristics of Obstructive Sleep Apnea in Psychiatric Disease

Patients with serious psychiatric diseases (major depressive disorder (MDD), bipolar disorder (BD), and schizophrenia and psychotic disorder) often complain about sleepiness during the day, fatigue, low energy, concentration problems, and insomnia; unfortunately, many of these symptoms are also frequent in patients with Obstructive Sleep Apnea (OSA). However, existing data about the clinical appearance of OSA in Psychiatric Disease are generally missing. The aim of our study was a detailed and focused evaluation of OSA in Psychiatric Disease, in terms of symptoms, comorbidities, clinical characteristics, daytime respiratory function, and overnight polysomnography data. We examined 110 patients (56 males and 54 females) with stable Psychiatric Disease (Group A: 66 with MDD, Group B: 34 with BD, and Group C: 10 with schizophrenia). At baseline, each patient answered the STOP-Bang Questionnaire, Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), and Hospital Anxiety and Depression Scale (HADS) and underwent clinical examination, oximetry, spirometry, and overnight polysomnography. Body Mass Index (BMI), neck, waist, and hip circumferences, and arterial blood pressure values were also measured. The mean age of the whole population was 55.1 ± 10.6 years. The three groups had no statistically significant difference in age, BMI, hip circumference, and systolic and diastolic arterial blood pressure. Class II and III obesity with BMI > 35 kg/m² was observed in 36 subjects (32.14%). A moderate main effect of psychiatric disease was observed in neck (p = 0.044, η² = 0.064) and waist circumference (p = 0.021, η² = 0.078), with the depression group showing the lowest values, and in pulmonary function (Forced Vital Capacity (FVC, %), p = 0.013, η² = 0.084), with the psychotic group showing the lowest values. Intermediate to high risk of OSA was present in 87.37% of participants, according to the STOP-Bang Questionnaire (≥3 positive answers), and 70.87% responded positively for feeling tired or sleepy during the day. An Apnea-Hypopnea Index (AHI) ≥ 15 events per hour of sleep was recorded in 72.48% of our patients. AHI was associated positively with male sex, schizophrenia, neck, and waist circumferences, STOP-Bang and ESS scores, and negatively with respiratory function. A large main effect of psychiatric medications was observed in waist circumference (p = 0.046, η² = 0.151), FVC (%) (p = 0.027, η² = 0.165), and in time spend with SaO₂ < 90% (p = 0.006, η² = 0.211). Our study yielded that patients with Psychiatric Disease are at risk of OSA, especially men suffering from schizophrenia and psychotic disorders that complain about sleepiness and have central obesity and disturbed respiratory function. Screening for OSA is mandatory in this medical population, as psychiatric patients have significantly poorer physical health than the general population and the coexistence of the two diseases can further negatively impact several health outcomes.

Polysomnography Reference Values in Healthy Newborns

STUDY OBJECTIVES

Polysomnography (PSG) is increasingly used in the assessment of infants. Newborn PSG reference values based on recent standardization are not available. This study provides reference values for PSG variables in healthy newborn infants.

METHODS

Cross-sectional study of normal term newborn infants using standardized PSG collection and American Academy of Sleep Medicine interpretation criteria.

RESULTS

Thirty infants born between 37 and 42 weeks gestation underwent PSG testing before 30 days of age (mean 19.6 days). The infants had a mean sleep efficiency of 71% with average proportions of transitional, NREM and REM sleep estimated at 16.1%, 43.3% and 40.6% respectively. Mean arousal index was 14.7 events/h with respiratory arousal index of 1.2 events/h. Mean apnea-hypopnea index (AHI) was 14.9 events/h. Central, obstructive, and mixed apnea indices were 5.4, 2.3, and 1.2 events/h respectively. Mean oxygen saturation in sleep was 97.9% with a nadir of 84.4%. Mean end tidal CO₂ was 35.4 mmHg with an average of 6.2% of sleep time spent above end-tidal CO₂ 45 mmHg and 0.6% above 50 mmHg.

CONCLUSIONS

The sleep efficiency was significantly lower and the AHI was significantly higher compared to healthy children older than 1 year. The AHI was also higher than reported in healthy infants older than 1 month. These findings suggest current severity classifications of sleep apnea may not apply to newborn infants.

The role of polysomnography in decannulation of children with brain and spinal cord injuries

OBJECTIVE

The objective of this retrospective review was to determine the utility of polysomnography (PSG) in influencing the decision to decannulate pediatric patients with brain and spinal cord injuries in an inpatient rehabilitation hospital setting.

METHODS

Between 2010 and 2016, data were collected on pediatric patients with brain and/or spinal cord injuries who had PSG performed with the goal of decannulation. Patients underwent a decannulation protocol involving toleration of continuous tracheostomy capping and bedside tracheoscopy by otolaryngology. Decision to decannulate was determined with input from multiple disciplines. Associations were examined between decannulation success and findings on PSG as well as demographic factors, injury characteristics, otolaryngology findings, and timeline from initial injury to selected events.

RESULTS

A total of 46 patients underwent PSG, after which 38 (83%) were deemed appropriate and eight (17%) were deemed inappropriate for decannulation. Individuals who were deemed ready for decannulation had significantly lower obstructive apnea hypopnea indexes (AHI) (1.7 vs 5.4 events/h, P = 0.03), respiratory disturbance indexes (RDI) (2.4 vs 7.6 events/h, P = 0.006), and peak end tidal carbon dioxide (CO₂ ) levels (50.0 vs 58.7 torr, P = 0.009) on PSG compared to those who were not decannulated. There were no complications following decannulation prior to discharge.

CONCLUSION

PSG provided important additional information as part of a multidisciplinary team assessment of clinical readiness for decannulation in pediatric patients with brain and spinal cord injuries who underwent a decannulation protocol. Obstructive AHI, RDI, and peak end tidal CO₂ level were associated with successful decannulation prior to discharge from inpatient rehabilitation.

Comparison of Pre- and Postoperative Sleep Studies in Patients Undergoing Sphincter Pharyngoplasty

OBJECTIVE

To determine if sphincter pharyngoplasty changes sleep study parameters on patients undergoing surgery for velopharyngeal insufficiency (VPI).

DESIGN

Retrospective chart review on patients undergoing sphincter pharyngoplasty for VPI with pre- and postoperative polysomnography completed.

SETTING

Institutional study at a tertiary pediatric hospital.

PATIENTS

All patients who underwent sphincter pharyngoplasty over a 20-year period were reviewed; all patients with both pre- and postoperative sleep studies were collected for evaluation.

INTERVENTIONS

Sphincter pharyngoplasty for patients with VPI.

MAIN OUTCOME MEASURE

Sleep study parameters collected include apnea-hypopnea index (AHI), obstructive and central apneas, hypopneas, and mixed events. The preoperative values were compared to postoperative values.

RESULTS

There were 98 patients collected with sleep studies for review. Of these, 32 patients had both pre- and postoperative sleep studies. The AHI increased from 1.8 preoperatively to a postoperative value of 4.8 ( P = .004). The number of obstructive events per night went from 4.6 to 17.6 postoperatively ( P = .04). The number of hypopneas increased from 4.0 to 13.6 ( P = .003). The other parameters were not statistically different, central events decreased from 4.8 to 2.1 ( P = .086), and mixed events were essentially unchanged from 0.2 to 0.5 ( P = .17) events per night.

CONCLUSIONS

Patients undergoing sphincter pharyngoplasty for VPI may experience an increase in their postoperative AHI, obstructive events per night, and hypopneas. Sleep studies should be performed both pre- and postoperatively to assess the need for intervention or change in management.

Sleep-disordered breathing in hypertensive disorders of pregnancy: a BMI-matched study

Sleep-disordered breathing is more common in hypertensive disorders during pregnancy; however, most studies have not adequately accounted for the potential confounding impact of obesity. This study evaluated the frequency of sleep-disordered breathing in women with gestational hypertension and pre-eclampsia compared with body mass index- and gestation-matched normotensive pregnant women. Women diagnosed with gestational hypertension or pre-eclampsia underwent polysomnography shortly after diagnosis. Normotensive controls body mass index-matched within ±4 kg m^-2 underwent polysomnography within ±4 weeks of gestational age of their matched case. The mean body mass index and gestational age at polysomnography were successfully matched for 40 women with gestational hypertension/pre-eclampsia and 40 controls. The frequency of sleep-disordered breathing in the cases was 52.5% compared with 37.5% in the control group (P = 0.18), and the respiratory disturbance index overall did not differ (P = 0.20). However, more severe sleep-disordered breathing was more than twice as common in women with gestational hypertension or pre-eclampsia (35% versus 15%, P = 0.039). While more than half of women with a hypertensive disorder of pregnancy meet the clinical criteria for sleep-disordered breathing, it is also very common in normotensive women of similar body mass index. This underscores the importance of adjusting for obesity when exploring the relationship between sleep-disordered breathing and hypertension in pregnancy. More severe degrees of sleep-disordered breathing are significantly associated with gestational hypertension and pre-eclampsia, and sleep-disordered breathing may plausibly play a role in the pathophysiology of pregnancy hypertension in these women. This suggests that more severe sleep-disordered breathing is a potential therapeutic target for reducing the prevalence or severity of hypertensive disorders in pregnancy.

Adherence to Symptom-Based Care Guidelines for Down Syndrome

To assess adherence to symptom-based studies recommended in the health supervision guidelines for Down syndrome from the American Academy of Pediatrics (AAP), 24 pediatric care sites participated in retrospective chart review. Symptom-based screening and 4 associated recommendations, including cervical spine radiograph, video swallow study, celiac study with tissue transglutaminase and sleep study were analyzed by reviewing well-child visit notes of 264 children with Down syndrome. Given trends toward symptom-based screens, Pearson's chi-square test and Fisher's exact test were used to determine the association between symptom presence and receiving corresponding symptom-based screens. Adherence rates were widely variable ranging from 0% to 79% completion. Symptom-based studies were performed in 22% to 36% of patients. Symptom screens were documented positive in many patients, but the presence of symptoms did not correlate with completion of symptom-based screens. Symptom-based screening is low; associated studies were performed in patients without documented symptoms contrary to AAP recommendation.

Obstructive Sleep Apnea Resolution in Hypopnea- versus Apnea-Predominant Children after Adenotonsillectomy

OBJECTIVE

Given that 30% to 40% of children have persistent obstructive sleep apnea (OSA) after adenotonsillectomy, we evaluated whether children with hypopnea-predominant OSA were more likely to have complete disease resolution after adenotonsillectomy than those with apnea-predominant disease. We also identified risk factors that might modify the relationship between disease resolution and polysomnographic event type (ie, hypopnea vs apnea).

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary pediatric hospital.

SUBJECTS/METHODS

Consecutive 1- to 18-year-old typically developing children diagnosed with OSA from March 2011 to December 2012 underwent adenotonsillectomy and completed pre- and postoperative polysomnography within 1 year of surgery.

RESULTS

Fifty-eight children were included (27 female; mean ± SD: age, 5.6 ± 3.1 years; body mass index z score, 1.1 ± 1.7). Overall, adenotonsillectomy resulted in significant improvement in obstructive apnea-hypopnea index (oAHI) from 23.3 ± 40.0 to 4.3 ± 8.2 events per hour (P < .001), obstructive apnea index (5.1 ± 7.4 to 0.4 ± 0.8, P < .001), and obstructive hypopnea index (oHI; 18.1 ± 37.5 to 3.7 ± 8.1, P < .001). There was complete response (oAHI <1.0 event/h) in 24 of 58 patients (41%) but no difference by event type (P = .11). On univariate analysis, only race, sex, oxygen saturation nadir, and oHI were predictive of response to adenotonsillectomy, while multivariate analysis found that prematurity, age, oxygen saturation nadir, oHI, obstructive apnea index, and oAHI were predictive. Event type was not significant, even in a model controlling for age, race, sex, prematurity, asthma, body mass index, and baseline polysomnographic variables.

CONCLUSION

This small study demonstrated no difference in disease resolution between children with hypopnea- and apnea-predominant OSA who underwent adenotonsillectomy. Additionally, adenotonsillectomy significantly improved OSA in most children, and high preoperative oAHI was associated with persistent postoperative OSA.

Comparison of clinical features and polysomnographic findings between men and women with sleep apnea

BACKGROUND

There is a scarcity of reports comparing gender differences in polysomnographic findings among Asian patients with sleep apnea (SA). In this study, we elucidated gender differences in the clinical features and polysomnographic findings of SA patients in Japan.

METHODS

We conducted a case-matched control study to compare the gender differences. A total of 4,714 patients (4,127 men; 587 women) were matched for age, apnea-hypopnea index (AHI), and body mass index (BMI). The criteria used for sex matching were (I) age ±4 years, (II) AHI ± 4 h of sleep, and (III) BMI ±2 kg/m(2). This facilitated the comparison of polysomnography sleep variables in 296 men and 296 women with SA.

RESULTS

Compared with their male counterparts, female SA patients had a significantly higher rapid eye movement AHI [men: 27.7 (IQR, 14.3-45.2); women: 43.3 (IQR, 25.5-56.6); P<0.001], lower supine AHI [men: 29.7 (IQR, 16.8-49.5); women: 25.0 (IQR, 14.7-39.3); P=0.004], longer total sleep time (TST), and non-rapid eye movement (NREM) sleep stage 3 (N3), %TST [TST in men: 356.3 (IQR, 319.5-392.3); women: 372.0 (IQR, 327.8-404.5); P=0.007; N3, %TST in men: 8.8 (IQR, 3.0-14.6); women: 14.4 (IQR, 8.3-20.4); P<0.001], and better sleep efficiency [men: 80.9 (IQR, 71.0-88.0); women: 83.2 (IQR, 74.5-90.0); P=0.011].

CONCLUSIONS

This study revealed that women with SA had a significantly longer TST and N3, %TST, which represents deep sleep. Future prospective studies must be conducted together with polysomnography tests including electromyography of pharyngeal muscle expansion and electroencephalography.

Consensus and evidence-based Indian initiative on obstructive sleep apnea guidelines 2014 (first edition)

Obstructive sleep apnea (OSA) and obstructive sleep apnea syndrome (OSAS) are subsets of sleep-disordered breathing. Awareness about OSA and its consequences among the general public as well as the majority of primary care physicians across India is poor. This necessitated the development of the Indian initiative on obstructive sleep apnea (INOSA) guidelines under the auspices of Department of Health Research, Ministry of Health and Family Welfare, Government of India. OSA is the occurrence of an average five or more episodes of obstructive respiratory events per hour of sleep with either sleep-related symptoms or co-morbidities or ≥15 such episodes without any sleep-related symptoms or co-morbidities. OSAS is defined as OSA associated with daytime symptoms, most often excessive sleepiness. Patients undergoing routine health check-up with snoring, daytime sleepiness, obesity, hypertension, motor vehicular accidents, and high-risk cases should undergo a comprehensive sleep evaluation. Medical examiners evaluating drivers, air pilots, railway drivers, and heavy machinery workers should be educated about OSA and should comprehensively evaluate applicants for OSA. Those suspected to have OSA on comprehensive sleep evaluation should be referred for a sleep study. Supervised overnight polysomnography is the “gold standard” for evaluation of OSA. Positive airway pressure (PAP) therapy is the mainstay of treatment of OSA. Oral appliances (OA) are indicated for use in patients with mild to moderate OSA who prefer OA to PAP, or who do not respond to PAP or who fail treatment attempts with PAP or behavioral measures. Surgical treatment is recommended in patients who have failed or are intolerant to PAP therapy.

The utility of polysomnography for the diagnosis of NREM parasomnias: an observational study over 4 years of clinical practice

Polysomnography (PSG) is considered the gold standard for diagnosis of non-rapid eye movement (NREM) parasomnias, however its diagnostic yield has been rarely reported. We aimed to assess the diagnostic value of polysomnography in different categories of patients with suspected NREM parasomnia and define variables that can affect the outcome. 124 adults referred for polysomnography for suspected NREM parasomnia were retrospectively identified and divided into clinical categories based on their history. Each polysomnography was analysed for features of NREM parasomnia or different sleep disorders and for presence of potential precipitants. The impact on the outcome of number of recording nights and concomitant consumption of benzodiazepines and antidepressants was assessed. Overall, PSG confirmed NREM parasomnias in 60.5 % patients and showed a different sleep disorder in another 16 %. Precipitants were found in 21 % of the 124 patients. However, PSG showed limited value when the NREM parasomnia was clinically uncomplicated, since it rarely revealed a different diagnosis or unsuspected precipitants (5 % respectively), but became essential for people with unusual features in the history where different or overlapping diagnoses (18 %) or unsuspected precipitants (24 %) were commonly identified. Taking benzodiazepines or antidepressants during the PSG reduced the diagnostic yield. PSG has a high diagnostic yield in patients with suspected NREM parasomnia, and can reveal a different diagnosis or precipitants in over 40 % of people with complicated or atypical presentation or those with a history of epilepsy. We suggest that PSG should be performed for one night in the first instance, with leg electrodes and respiratory measurements and after benzodiazepine and antidepressant withdrawal.

Consensus & evidence-based INOSA Guidelines 2014 (first edition)

Obstructive sleep apnoea (OSA) and obstructive sleep apnoea syndrome (OSAS) are subsets of sleep-disordered breathing. Awareness about OSA and its consequences amongst the general public as well as the majority of primary care physcians across India is poor. This necessiated the development of the INdian initiative on Obstructive sleep apnoea (INOSA) guidelines under the auspices of Department of Health Research, Ministry of Health & Family Welfare, Government of India. OSA is the occurrence of an average five or more episodes of obstructive respiratory events per hour of sleep with either sleep related symptoms or co-morbidities or ≥ 15 such episodes without any sleep related symptoms or co-morbidities. OSAS is defined as OSA associated with daytime symptoms, most often excessive sleepiness. Patients undergoing routine health check-up with snoring, daytime sleepiness, obesity, hypertension, motor vehicular accidents and high risk cases should undergo a comprehensive sleep evaluation. Medical examiners evaluating drivers, air pilots, railway drivers and heavy machinery workers should be educated about OSA and should comprehensively evaluate applicants for OSA. Those suspected to have OSA on comprehensive sleep evaluation should be referred for a sleep study. Supervised overnight polysomnography (PSG) is the "gold standard" for evaluation of OSA. Positive airway pressure (PAP) therapy is the mainstay of treatment of OSA. Oral appliances are indicated for use in patients with mild to moderate OSA who prefer oral appliances to PAP, or who do not respond to PAP or who fail treatment attempts with PAP or behavioural measures. Surgical treatment is recommended in patients who have failed or are intolerant to PAP therapy.

Feasibility of comprehensive, unattended ambulatory polysomnography in school-aged children

STUDY OBJECTIVES

Although unattended ambulatory polysomnography (PSG) is frequently performed in adults, few studies have been performed in children. The objective of this study was to evaluate the feasibility of comprehensive, ambulatory PSG, including electroencephalography, in school-aged children in the home environment.

METHODS

A total of 201 children, born premature with birth weights of 500-1,250 grams, currently aged 5-12 years and living in Canada and Australia, underwent unattended ambulatory PSG.

RESULTS

PSG was initially technically satisfactory in 183 (91%) cases. Fourteen studies were satisfactory when repeated, resulting in an overall satisfactory rate of 197 (98%). Artifact-free signals were obtained for ≥ 75% of recording time in more than 92% of subjects, with the exception of nasal pressure, which was satisfactory for ≥ 75% of recording time in only 67% of subjects. However, thermistry signals were satisfactory for ≥ 75% of recording time in 92% of subjects, and some measure of airflow was present for ≥ 75% of recording time in 96% of subjects. Children slept very well, with a long total sleep time (534 ± 73 [mean ± SD] minutes), high sleep efficiency (92% ± 5%), and low arousal index (9 ± 3/h). Parents and children reported a high rate of satisfaction with the study.

CONCLUSIONS

This large, international study has shown that comprehensive, unattended, ambulatory PSG is feasible, technically adequate and well-tolerated in school-aged children when performed under research conditions. Further studies regarding the cost efficacy of this approach, and generalizability of the findings to a clinical population, are warranted.

Mandible behaviour interpretation during wakefulness, sleep and sleep-disordered breathing

The mandible movement (MM) signal provides information on mandible activity. It can be read visually to assess sleep-wake state and respiratory events. This study aimed to assess (1) the training of independent scorers to recognize the signal specificities; (2) intrascorer reproducibility and (3) interscorer variability. MM was collected in the mid-sagittal plane of the face of 40 patients. The typical MM was extracted and classified into seven distinct pattern classes: active wakefulness (AW), quiet wakefulness or quiet sleep (QW/S), sleep snoring (SS), sleep obstructive events (OAH), sleep mixed apnea (MA), respiratory related arousal (RERA) and sleep central events (CAH). Four scorers were trained; their diagnostic capacities were assessed on two reading sessions. The intra- and interscorer agreements were assessed using Cohen's κ. Intrascorer reproducibility for the two sessions ranged from 0.68 [95% confidence interval (CI): 0.59-0.77] to 0.88 (95% CI: 0.82-0.94), while the between-scorer agreement amounted to 0.68 (95% CI: 0.65-0.71) and 0.74 (95% CI: 0.72-0.77), respectively. The overall accuracy of the scorers was 75.2% (range: 72.4-80.7%). CAH MMs were the most difficult to discern (overall accuracy 65.6%). For the two sessions, the recognition rate of abnormal respiratory events (OAH, CAH, MA and RERA) was excellent: the interscorer mean agreement was 90.7% (Cohen's κ: 0.83; 95% CI: 0.79-0.88). The discrimination of OAH, CAH, MA characteristics was good, with an interscorer agreement of 80.8% (Cohen's κ: 0.65; 95% CI: 0.62-0.68). Visual analysis of isolated MMs can successfully diagnose sleep-wake state, normal and abnormal respiration and recognize the presence of respiratory effort.

Eszopiclone improves overnight polysomnography and continuous positive airway pressure titration: a prospective, randomized, placebo-controlled trial

STUDY OBJECTIVES

To assess whether premedication with eszopiclone would improve sleep duration and continuity during polysomnography, thereby improving the quality of diagnostic and CPAP titration studies.

DESIGN

Prospective, double-blinded, placebo-controlled trial

SETTING

Academic, multidisciplinary sleep center.

PATIENTS

226 adult subjects undergoing polysomnography for suspected sleep disordered breathing; 113 received eszopiclone and 113 received placebo.

INTERVENTIONS

Subjects received eszopiclone 3 mg or matching placebo before polysomnography. We compared sleep latency, efficiency, total sleep time, and apnea-hypopnea index between these groups. We also compared rates of inadequate studies, defined as insufficient sleep time (< 120 min or sleep efficiency < or = 70%) or incomplete CPAP titrations (> or = 5 events/h on the highest CPAP or complete intolerance).

MEASUREMENTS AND RESULTS

Eszopiclone premedication significantly improved a number of measured variables. Eszopiclone reduced sleep latency (21.7 +/- 27.1 vs. 32.6 +/- 38.2 min, P = 0.014), improved sleep efficiency (87.6% +/- 10.8% vs. 78.1% +/- 15.6%, P < 0.001), reduced wake after sleep onset (39.2 +/- 31.9 vs. 64.5 +/- 45.4 min, P <0.001) and prolonged sleep time (346.5 +/- 53.1 vs. 312.2 +/- 64.2 min, P < 0.001). Sleep efficiencies < or = 70% were more common with placebo than medication (21.2% vs. 7.1%, P = 0.004). Eszopiclone facilitated improved CPAP titrations with fewer residual events (5.7 +/- 10.3 vs. 11.9 +/- 19.6, P = 0.02) and fewer incomplete titrations (31.1% vs. 48.0%, P = 0.04). Poor quality studies (46.0% vs. 26.5%, P = 0.004) were more common with placebo than with eszopiclone. There was a trend for more non-usable studies with placebo (7.1% vs. 2.7%, P = 0.22). Side effects were uncommon and did not differ between groups.

CONCLUSION

Pretreatment with eszopiclone improves the quality of polysomnography and CPAP titration and decreases the need to repeat studies. Given the ever-growing demand for polysomnography and the need to improve efficiency, the routine use of nonbenzodiazepines as premedication for polysomnography should be considered.