Utilizing inspiratory airflows during standard polysomnography to assess pharyngeal function in children during sleep

Leptin signaling in the dorsomedial hypothalamus couples breathing and metabolism in obesity

Mismatch between CO2 production (Vco2) and respiration underlies the pathogenesis of obesity hypoventilation. Leptin-mediated CNS pathways stimulate both metabolism and breathing, but interactions between these functions remain elusive. We hypothesized that LEPRb+ neurons of the dorsomedial hypothalamus (DMH) regulate metabolism and breathing in obesity. In diet-induced obese LeprbCre mice, chemogenetic activation of LEPRb+ DMH neurons increases minute ventilation (Ve) during sleep, the hypercapnic ventilatory response, Vco2, and Ve/Vco2, indicating that breathing is stimulated out of proportion to metabolism. The effects of chemogenetic activation are abolished by a serotonin blocker. Optogenetic stimulation of the LEPRb+ DMH neurons evokes excitatory postsynaptic currents in downstream serotonergic neurons of the dorsal raphe (DR). Administration of retrograde AAV harboring Cre-dependent caspase to the DR deletes LEPRb+ DMH neurons and abolishes metabolic and respiratory responses to leptin. These findings indicate that LEPRb+ DMH neurons match breathing to metabolism through serotonergic pathways to prevent obesity-induced hypoventilation.

Pediatric obstructive sleep apnea: Preoperative and neurocognitive considerations for perioperative management

Obstructive sleep apnea (OSA) affects up to 7.5% of the pediatric population and is associated with a variety of behavioral and neurocognitive sequelae. Prompt diagnosis and treatment is critical to halting and potentially reversing these changes. Depending on the severity of the OSA and comorbid conditions, different treatment paradigms can be pursued, each of which has its own unique risk:benefit ratio. Adenotonsillectomy is first-line recommended surgical treatment for pediatric OSA. However, it carries its own perioperative risks and the decision regarding surgical timing is therefore made in the context of procedural risk versus patient benefit. This article presents the seminal perioperative and neurocognitive risks from pediatric OSA to aid with perioperative management.

Snoring and stertor are associated with more sleep disturbance than apneas and hypopneas in pediatric SDB

PURPOSE

Polysomnography is not recommended for children at home and does not adequately capture partial upper airway obstruction (snoring and stertor), the dominant pathology in pediatric sleep-disordered breathing. New methods are required for assessment. Aims were to assess sleep disruption linked to partial upper airway obstruction and to evaluate unattended Sonomat use in a large group of children at home.

METHODS

Children with suspected obstructive sleep apnea (OSA) had a single home-based Sonomat recording (n = 231). Quantification of breath sound recordings allowed identification of snoring, stertor, and apneas/hypopneas. Movement signals were used to measure quiescent (sleep) time and sleep disruption.

RESULTS

Successful recordings occurred in 213 (92%) and 113 (53%) had no OSA whereas only 11 (5%) had no partial obstruction. Snore/stertor occurred more frequently (15.3 [5.4, 30.1] events/h) and for a longer total duration (69.9 min [15.7, 140.9]) than obstructive/mixed apneas and hypopneas (0.8 [0.0, 4.7] events/h, 1.2 min [0.0, 8.5]); both p < 0.0001. Many non-OSA children had more partial obstruction than those with OSA. Most intervals between snore and stertor runs were < 60 s (79% and 61% respectively), indicating that they occur in clusters. Of 14,145 respiratory-induced movement arousals, 70% were preceded by runs of snore/stertor with the remainder associated with apneas/hypopneas.

CONCLUSIONS

Runs of snoring and stertor occur much more frequently than obstructive apneas/hypopneas and are associated with a greater degree of sleep disruption. Children with and without OSA are frequently indistinguishable regarding the amount, frequency, and the degree of sleep disturbance caused by snoring and stertor.

Pediatric Pulmonology year in review 2016: Part 1

Pediatric Pulmonology continues to publish research and clinical topics related to the entire range of children's respiratory disorders. As we have done annually in recent years, we here summarize the past year's publications in our major topic areas, as well as selected literature in these areas from other core journals relevant to our discipline. This review (Part 1) covers selected articles on sleep, diagnostic testing/endoscopy, respiratory complications of neuromuscular disorders, and rare lung diseases.

How do we recognize the child with OSAS?

Obstructive sleep-disordered breathing includes a spectrum of clinical entities with variable severity ranging from primary snoring to obstructive sleep apnea syndrome (OSAS). The clinical suspicion for OSAS is most often raised by parental report of specific symptoms and/or abnormalities identified by the physical examination which predispose to upper airway obstruction (e.g., adenotonsillar hypertrophy, obesity, craniofacial abnormalities, neuromuscular disorders). Symptoms and signs of OSAS are classified into those directly related to the intermittent pharyngeal airway obstruction (e.g., parental report of snoring, apneic events) and into morbidity resulting from the upper airway obstruction (e.g., increased daytime sleepiness, hyperactivity, poor school performance, inadequate somatic growth rate or enuresis). History of premature birth and a family history of OSAS as well as obesity and African American ethnicity are associated with increased risk of sleep-disordered breathing in childhood. Polysomnography is the gold standard method for the diagnosis of OSAS but may not be always feasible, especially in low-income countries or non-tertiary hospitals. Nocturnal oximetry and/or sleep questionnaires may be used to identify the child at high risk of OSAS when polysomnography is not an option. Endoscopy and MRI of the upper airway may help to identify the level(s) of upper airway obstruction and to evaluate the dynamic mechanics of the upper airway, especially in children with combined abnormalities. Pediatr Pulmonol. 2017;52:260-271. © 2016 Wiley Periodicals, Inc.