Pediatric polysomnographic studies at a tertiary-care hospital in Singapore

Worldwide prevalence and associated risk factors of obstructive sleep apnea: a meta-analysis and meta-regression

PURPOSE

This study aimed to identify the prevalence of obstructive sleep apnea (OSA) and associated risk factors globally.

METHODS

Six databases and registrations and three grey databases were explored for observational field research. Independently and impartially paired reviewers selected research, gathered data, and evaluated the methodological quality. Heterogeneity was investigated using subgroup analysis and meta-regression following the moderating variable in a meta-analysis of proportions with a random-effects model. The critical appraisal instrument developed by the Joanna Briggs Institute was used to evaluate the listed studies' methodology. The certainty of the evidence was evaluated using the GRADE tool.

RESULTS

A total of 8236 articles were collected during the database search, resulting in 99 articles included for qualitative synthesis, and 98 articles were included for the meta-analysis. The estimated combined prevalence of OSA was 54% [CI 95% = 46-62%; I2 = 100%]. Mean age, percentage of moderate-severe cases, and the sample's body mass index (BMI) did not affect the heterogeneity that was already present when meta-regressed (p > 0.05). Ninety-one studies were deemed to have a low risk of bias, while eight were deemed to have a moderate risk. For OSA prevalence outcomes, the GRADE criteria were considered very low.

CONCLUSION

Approximately half of the people worldwide have OSA. High BMI, increasing age, and male gender are described as risk factors in the literature, but these covariates do not affect pre-existing heterogeneity.

Restless sleep in children: A systematic review

This systematic review assessed the prevalence of restless sleep in children, documented the association of restless sleep with other conditions, and summarized the existing evidence regarding whether restless sleep should be considered a distinct sleep disorder. A comprehensive search of electronic databases was performed using the broad search term "restless sleep" in all fields. Of the 266 articles retrieved, 107 were retained for inclusion in this review. The majority (n = 93) were observational studies. The studies were grouped under several pathologic/condition categories: sleep-disordered breathing (n = 19); adenotonsillectomy (n = 7); respiratory disorders, otitis media, and smoke exposure (n = 12); sleep-related movement disorders and restless sleep disorder (n = 11); neurologic or psychiatric disorders (n = 7); Down syndrome/other neurodevelopmental disorders (n = 10); sleep-related bruxism and other sleep disorders (n = 7); and restless sleep in the general population/mixed clinical samples (n = 18). A high prevalence of restless sleep was found in children with many of these underlying conditions, likely related to associated inherent sleep disruption and frequent awakenings (e.g., apnea and periodic limb movements), pain, sleep instability, and caregiver perception. The majority of studies identified restless sleep as reported by the caregiver, only 34 studies attempted to define restless sleep further. Four studies provided supportive evidence for designating restless sleep as an independent sleep disorder, restless sleep disorder (RSD). This review highlights the fact that the prevalence, etiology and sequelae (including daytime impairments) of restless sleep in children are important topics deserving of further research and that clinical definitions based on empirical evidence need to be developed. The designation of "primary" versus "secondary" restless sleep may be a useful construct, especially with regard to developing clinical trials and treatment algorithms.

Developmental Profile of Sleep and Its Potential Impact on Daytime Functioning from Childhood to Adulthood in Sickle Cell Anaemia

Young individuals with sickle cell anaemia (SCA) experience sleep disturbances and often experience daytime tiredness, which in turn may impact on their daytime functioning and academic attainment, but there are few longitudinal data.

METHODS

Data on sleep habits and behaviour were taken on the same day as an in-hospital polysomnography. This study assesses the developmental sleep profiles of children and young adults aged 4-23 years old with SCA. We examined retrospective polysomnography (PSG) and questionnaire data.

RESULTS

A total of 256 children with a median age of 10.67 years (130 male) were recruited and 179 returned for PSG 1.80-6.72 years later. Later bedtimes and a decrease in total sleep time (TST) were observed. Sleep disturbances, e.g., parasomnias and night waking, were highest in preschool children and young adults at their first visit. Participants with lower sleep quality, more movement during the night and increased night waking experienced daytime sleepiness, potentially an indicator of lower daytime functioning. Factors influencing sleep quantity included age, hydroxyurea prescription, mean overnight oxygen saturation, sleep onset latency, periodic limb movement, socioeconomic status and night waking.

CONCLUSION

Sleep serves an important role for daytime functioning in SCA; hence, quantitative (i.e., PSG for clinical symptoms, e.g., sleep-disordered breathing, nocturnal limb movement) and qualitative (i.e., questionnaires for habitual sleep behaviour) assessments of sleep should be mutually considered to guide interventions.

The Visual Scoring of Sleep in Infants 0 to 2 Months of Age

In March 2014, the American Academy of Sleep Medicine (AASM) Board of Directors requested the Scoring Manual Editorial Board develop rules, terminology, and technical specifications for scoring sleep/wake states in full-term infants from birth to 2 mo of age, cognizant of the 1971 Anders, Emde, and Parmelee Manual for Scoring Sleep in Newborns. On July 1, 2015, the AASM published rules for scoring sleep in infants, ages 0-2 mo. This evidence-based review summarizes the background information provided to the Scoring Manual Editorial Board to write these rules. The Anders Manual only provided criteria for coding physiological and behavioral state characteristics in polysomnograms (PSG) of infants, leaving specific sleep scoring criteria to the individual investigator. Other infant scoring criteria have been published, none widely accepted or used. The AASM Scoring Manual infant scoring criteria incorporate modern concepts, digital PSG recording techniques, practicalities, and compromises. Important tenets are: (1) sleep/wake should be scored in 30-sec epochs as either wakefulness (W), rapid eye movement, REM (R), nonrapid eye movement, NREM (N) and transitional (T) sleep; (2) an electroencephalographic (EEG) montage that permits adequate display of young infant EEG is: F3-M2, F4-M1, C3-M2, C4-M1, O1-M2, O2-M1; additionally, recording C3-Cz, Cz-C4 help detect early and asynchronous sleep spindles; (3) sleep onsets are more often R sleep until 2-3 mo postterm; (4) drowsiness is best characterized by visual observation (supplemented by later video review); (5) wide open eyes is the most crucial determinant of W; (6) regularity (or irregularity) of respiration is the single most useful PSG characteristic for scoring sleep stages at this age; (7) trace alternant (TA) is the only relatively distinctive EEG pattern, characteristic of N sleep, and usually disappears by 1 mo postterm replaced by high voltage slow (HVS); (8) sleep spindles first appear 44-48 w conceptional age (CA) and when present prompt scoring N; (9) score EEG activity in an epoch as "continuous" or "discontinuous" for inter-scorer reliability; (10) score R if four or more of the following conditions are present, including irregular respiration and rapid eye movement(s): (a) low chin EMG (for the majority of the epoch); (b) eyes closed with at least one rapid eye movement (concurrent with low chin tone); (c) irregular respiration; (d) mouthing, sucking, twitches, or brief head movements; and (e) EEG exhibits a continuous pattern without sleep spindles; (11) because rapid eye movements may not be seen on every page, epochs following an epoch of definite R in the absence of rapid eye movements may be scored if the EEG is continuous without TA or sleep spindles, chin muscle tone low for the majority of the epoch; and there is no intervening arousal; (12) Score N if four or more of the following conditions are present, including regular respiration, for the majority of the epoch: (a) eyes are closed with no eye movements; (b) chin EMG tone present; (c) regular respiration; and (d) EEG patterns of either TA, HVS, or sleep spindles are present; and (13) score T sleep if an epoch contains two or more discordant PSG state characteristics (either three NREM and two REM characteristics or two NREM and three REM characteristics). These criteria for ages 0-2 mo represent far more than baby steps. Like all the other AASM Manual rules and specifications none are fixed in stone, all open for debate, discussion and revision with the fundamental goal to provide standards for comparison of methods and results.

COMMENTARY

A commentary on this article appears in this issue on page 291.

Prevalence of Sleep Disorders in Thai Children

OBJECTIVE

To evaluate the prevalence of sleep disorders in Thai children who underwent polysomnography at a single institution.

METHODS

A retrospective analysis of pediatric polysomnographic studies was performed from January 2011 through December 2014.

RESULTS

One hundred sixty-six studies were conducted; 142, 7, and 17 were diagnostic, split-night, and positive airway pressure (PAP) titration studies, respectively. In total, 136 diagnostic/split-night studies were performed to diagnose sleep disorders with presentation of snoring (92.6 %), heavy breathing (0.7 %), witnessed apnea (14.7 %), excessive daytime sleepiness (10.3 %), hyperactivity (2.2 %), restless sleep (11.0 %), enuresis/nocturia (5.9 %), abnormal behavior (4.4 %) and poor weight gain (0.7 %). Eleven diagnostic studies and one split-night study were performed to follow-up obstructive sleep apnea (OSA) after adenoidectomy and/or tonsillectomy. One diagnostic study was conducted to follow-up OSA after postmandibular distraction. OSA was the most common diagnosis with a prevalence of 92.7 %; 40.4 % of patients were diagnosed with severe OSA. The prevalence of sleep-related hypoventilation was 15.4 %. The second most common diagnosis was periodic limb movement disorder with a prevalence of 20.6 %. Seventeen PAP titration studies were performed. Four CPAP titration studies were conducted for OSA treatment. Twelve bi-level (BiPAP) titration studies were performed in eight children with hypoventilation. One BiPAP/average volume-assured pressure support titration was conducted in a patient with congenital central hypoventilation syndrome (CCHS).

CONCLUSIONS

The prevalence of sleep disorders in Thai children who underwent polysomnography at a tertiary-care hospital is very high. The factors that contribute are the limited availability and high costs of polysomnography in Thailand. This information will encourage pediatricians to look for sleep disorders in children.