Obstructive Apnea and Hypopnea Length in Normal Children and Adolescents

(1) Background: Breathing is an essential function that requires both metabolic (or au-tomatic) and voluntary (behavioral) control during wakefulness but during sleep depends on metabolic control via peripheral and central chemoreceptors. Breathing during sleep disordered breathing also depends on the maturity of the neural centers and the strength of the respiratory muscles. We do not know if the response to apnea varies with age. (2) Methods: We measured the obstructive apneas and hypopneas during REM and NREM in polysomnography studies from children referred for snoring. Exclusion criteria: younger than 1 year of age, neuromuscular or syndrome comorbidity, oxygen or positive airway pressure, central apnea, and studies with loss of airflow sensors. (3) Results: Two-hundred-and-sixty-eight sleep studies were included. Mean age was 8.7 years (4.68 SD), range 1–18 years, 160 were male, and 108 were female. The 5th centile of apnea duration during NREM is above 8 s at all ages, with a tendency to increase in the oldest groups up to 10 s. During REM sleep, it shows a gradual increase from 6 s in the youngest children to 10 s in the oldest. (4) Conclusions: Apnea/hypopnea length increases with age in children and adolescents independently from sex or severity of OSA. Using adult criteria in teens seems to be accurate.

Comparisons of Temporal Characteristics of Respiration and Swallowing Coordination between Young and Elderly

Objectives: The relationship between breathing and swallowing is very dynamic during swallowing and these are highly temporally coordinated to protect the airway. The ability to protect airways during swallowing deteriorates with aging. In this study, we attempted to compare the breathing-swallowing pattern and temporal change in the respiration and swallowing coordination between young and elderly adults in Korea.Methods: A total of 80 normal people, including 40 young and 40 elderly people participated in this study. For measurement of breathing and swallowing coordination, Digital Swallowing Workstation^TM was used during a 5 mL water swallowing task. Temporal parameters related to breathing-swallowing including AS (acoustic start), AP (acoustic peak), AD (acoustic duration), SAS (swallowing apnea or respiration pause start), SAD (swallowing apena duration), sES (submental sEMG start), sEP (submental sEMG peak), sED (submental sEMG duration). Additionally, DHI (Dysphagia Handicap Index) was evaluated for self-assessment of the degree of difficulty swallowing.Results: Older adults displayed delayed swallowing-related acoustic signal measurements, swallowing apnea measurements, surface EMG measurements, and delayed sequential coordination time of swallowing-related structures during swallowing. There were no significant differences according to gender. Furthermore, a significant positive correlation was observed between the total K-DHI scores and as well as swallowing apnea duration in the elderly.Conclusion: In the older population, the different breathing-swallowing pattern from that of young adults may increase the risk of dysphagia. In addition, swallowing delays due to aging can be an indicator of elderly swallowing disorders. Moreover, an increase in apnea time during swallowing may be a phenomenon that appears as a mechanism for airway protection in the elderly. However, the high correlation between apnea time and K-DHI score in the elderly may make it difficult to maintain respiration for a long time during swallowing as the respiratory function decreases due to aging, which may increase the risk of experiencing symptoms such as choking and affect the degree of subjective swallowing disorder. This suggests that even if classified as a normal elderly person without a pathological swallowing disorder, swallowing training is needed to prevent swallowing disorders and to enhance swallowing ability for older people with degraded swallowing-related abilities.

Detecting Apnea/Hypopnea Events Time Location from Sound Recordings for Patients with Severe or Moderate Sleep Apnea Syndrome

The most common index for diagnosing Sleep Apnea Syndrome (SAS) is the Apnea-Hypopnea Index (AHI), defined as the average count of apnea/hypopnea events per sleeping hour. Despite its broad use in automated systems for SAS severity estimation, researchers now focus on individual event time detection rather than the insufficient classification of the patient in SAS severity groups. Towards this direction, in this work, we aim at the detection of the exact time location of apnea/hypopnea events. We particularly examine the hypothesis of employing a standard Voice Activity Detection (VAD) algorithm to extract breathing segments during sleep and identify the respiratory events from severely altered breathing amplitude within the event. The algorithm, which is tested only in severe and moderate patients, is applied to recordings from a tracheal and an ambient microphone. It proves good sensitivity for apneas, reaching 81% and 70.4% for the two microphones, respectively, and moderate sensitivity to hypopneas—approx. 50% were identified. The algorithm also presents an adequate estimator of the Mean Apnea Duration index—defined as the average duration of the detected events—for patients with severe or moderate apnea, with mean error 1.7 s and 3.2 s for the two microphones, respectively.

Physiological Parameters Monitored on Bottlenose Dolphin Neonates (Tursiops truncatus, Montagu 1821) over the First 30 Days of Life

Bottlenose dolphins (Tursiops truncatus) have been bred under human care for more than 60 years. Calves up to 30 days of life have presented the highest mortality rate, although comparable data for free-ranging neonates within this age group is not available. Husbandry measures to increase survivability have therefore been constantly improved. This work shows the results of a structured veterinary program that established the procedures to collect relevant physiological parameters on 13 calves during their first 30 days of life. Standardized observation protocols facilitated statistical analysis of the respiratory pattern, nursing, morphometric measurements and bloodwork. These allow early detection of health issues. Healthy neonates had longer apnea duration, despite the shape and size of the facility. The nursing pattern showed that successful calves started nursing 3 to 18 h postpartum. Although with different individual patterns, a steady increase in suckling time occurs during the first 24 h of life. The healthy neonates grew 0.428 ± 0.102 kg per day and the complete blood count profile, glucose, iron, blood urea nitrogen (BUN), total protein, Alanine aminotransferase (ALT), Aspartate aminotransferase (AST), Gamma-glutamyl transferase (GGT), creatinine and electrolytes values considered normal for healthy calves are provided. Furthermore, cholesterol, triglycerides, α-amylase, lipase, magnesium and cortisol are reported for the first time for such young calves. A list of indications for prompt intervention is included.

Hypoxic Respiratory Chemoreflex Control in Young Trained Swimmers

During an apnea, changes in PaO2 activate peripheral chemoreceptors to increase respiratory drive. Athletes with continuous apnea, such as breath-hold divers, have shown a decrease in hypoxic ventilatory response (HVR), which could explain the long apnea times; however, this has not been studied in swimmers. We hypothesize that the long periods of voluntary apnea in swimmers is related to a decreased HVR. Therefore, we sought to determine the HVR and cardiovascular adjustments during a maximum voluntary apnea in young-trained swimmers. In fifteen trained swimmers and twenty-seven controls we studied minute ventilation (VE), arterial saturation (SpO2), heart rate (HR), and autonomic response [through heart rate variability (HRV) analysis], during acute chemoreflex activation (five inhalations of pure N2) and maximum voluntary apnea test. In apnea tests, the maximum voluntary apnea time and the end-apnea HR were higher in swimmers than in controls (p < 0.05), as well as a higher low frequency component of HRV (p < 0.05), than controls. Swimmers showed lower HVR than controls (p < 0.01) without differences in cardiac hypoxic response (CHR). We conclude that swimmers had a reduced HVR response and greater maximal voluntary apnea duration, probably due to decreased HVR.

0697 Early Sleep Apnea Termination By Bone-conducted Sound Stimulation Reduces Oxygen Desaturation Magnitude And Duration

Introduction Obstructive sleep apneas (OSA) usually end with an oxygen desaturation and/or an arousal. In most epidemiological studies, OSA-associated oxygen desaturations are stronger predictors of cardiovascular morbidity than OSA-associated arousals. The aim of this study was to determine if induction of a premature arousal by a bone-conducted sound stimulation shortly after the onset of an event can reduce the magnitude of OSA-associated oxygen desaturation. Methods Eight severe OSA patients (2 women, 45 [20-68]y.o.) underwent polysomnography at the Lausanne University Sleep Center (CIRS). Short acoustic stimulations were administered every second sleep apnea by remote control using a Dreem® headband worn by the patients. Acoustic stimulations were administered by bone conduction. The magnitude(%) and the duration(s) of the oxygen desaturations following these prematurely-terminated apneas were compared with previous and following non-acoustic stimulated sleep apnea events. Results Analysis of 549 paired (stimulated-unstimulated) respiratory events in N1(14.2%), N2(69.9%), N3(4.2%), and REM sleep (9.6%) showed a 30.3% reduction in oxygen desaturation amplitude (mean difference±SD: -1.9±2.8%, p<0.0001), a 39.6% decrease in desaturation duration (-5.7±9.2 seconds, p<0.0001), and a 21.4% decrease in apnea duration (-3.4±7.2 seconds, p<0.0001) in stimulated apneas compared to the previous and subsequent non-stimulated apnea events. When analyzed individually, each patient showed a significant improvement following acoustic stimulation of events. Sound-associated discomfort was rated 1.14±1.53 on an 8 points scale (8=worst). Of the 68.6±38 administered sound stimuli per patient, only 6.8% of were perceived by the patients. A reduction in the desaturation amplitude occurred in each sleep stage but was milder in N3. Conclusion Bone-conducted sound stimuli applied trough a headband during the apneas decreased duration and magnitude of OSA-associated oxygen desaturation. These were well tolerated and often not perceived by the patient. This new treatment approach should be further investigated, with monitoring of its effect on cardiovascular parameters and daytime sleepiness. Support Customized Dreem headbands were provided by Dreem company