Diagnostic approach to obstructive sleep apnea in children

Obstructive sleep apnea syndrome (OSAS) in childhood is a disorder of breathing during sleep characterized by prolonged partial upper airway obstruction and/or intermittent complete obstruction that disrupts normal ventilation during sleep and normal sleep patterns. A spectrum of severity related to the degree of upper airway resistance, to the duration of the disease, to the presence or absence of hypoxemia episodes, and to certain clinical features can be described. Symptomatic children may not fit the criteria for diagnosis established for OSAS in adults; age-specific standards are needed. Both anatomical factors that increase upper airway resistance, e.g. adenotonsillar hypertrophy, and functional processes that decrease upper airway tone, e.g. REM sleep, contribute to the pathogenesis of pediatric OSAS. Sequelae of OSAS in children include neurobehavioural abnormalities, stunting of growth, and cor pulmonale. Both the history and physical examination should target the sleeping child; parents often report loud snoring, difficulty breathing, and obstructive apneas. The gold standard investigation to establish the diagnosis and to quantitate disease severity is overnight polysomnography. Home cardiopulmonary sleep studies have been shown to be an accurate and practical alternative to overnight laboratory polysomnography for routine evaluation of non-complex children with adenotonsillar hypertrophy. Children with documented severe OSAS are at increased post-operative risk for airway compromise and should be observed and monitored carefully. Adenotonsiliectomy is the most common therapy for OSAS in children; as a second-line treatment, the use of nasal CPAP in children with OSAS has been very successful in experienced hands.     

REVIEW ARTICLE: Sleep apnea in infants

Infancy is a developmental period characterized by instability of the control of breathing. Apneas of short duration are common, mostly central, and more frequent during rapid-eye-movement (REM) sleep. Obstructive apneas are rare in healthy control infants. Triggering factors such as respiratory syncitial virus infection can increase the frequency and the duration of apneas. Upper airway problems related to bone malformations, soft tissue infiltration, and neurologic lesions are responsible for obstructive apneas, but also for episodes of partial airway obstruction or upper airway resistance syndrome. In certain infants, an apparent-life-threatening event has been related to upper airway anomalies. Congenital central hypoventilation syndrome, a rare respiratory control disorder, may be presented by apneas. Polysomnography is the gold standard for the diagnosis of sleep-disordered-breathing in infants. Early diagnosis of abnormal breathing during sleep is of critical importance for the neurocognitive development in infants.     

Sleep apnea: clinical investigations in humans

Sleep apnea syndrome (SAS), a common disorder, is characterized by repetitive episodes of cessation of breathing during sleep, resulting in hypoxemia and sleep disruption. The consequences of the abnormal breathing during sleep include daytime sleepiness, neurocognitive dysfunction, development of cardiovascular disorders, metabolic dysfunction, and impaired quality of life. There are two types of SAS: obstructive sleep apnea syndrome (OSAS) and central sleep apnea syndrome (CSAS). OSAS is a prevalent disorder in which there is snoring, repetitive apneic episodes, and daytime sleepiness. Anatomical conditions causing upper airway obstruction (obesity or craniofacial abnormalities such as retrognathia or micrognathia) can cause OSAS. CSAS, much less common than OSAS, is a disorder characterized by cessation of breathing which is caused by reduced respiratory drive from the central nervous system to the muscles of respiration. The latter condition is common in patients with heart failure and cerebral neurologic diseases. The diagnosis of SAS requires assessment of subjective symptoms and apneic episodes during sleep documented by polysomnography. Treatments of OSAS include continuous positive airway pressure (CPAP), oral appliances, and surgery; patients with CSAS are treated with oxygen, adaptive servo-ventilation, or CPAP. With assessment and treatment of the SAS, patients usually have resolution of their disabling symptoms, subsequently resulting in improved quality of life.     

Sleep, breathing and the nose

During sleep there is a discrete fall in minute ventilation and an associated increase in upper airway resistance. In normal subjects, the nasal part of the upper airway contributes only little to the elevation of the total resistance, which is mainly the consequence of pharyngeal narrowing. Yet, swelling of the nasal mucosa due to congestion of the submucosal capacitance vessels may significantly affect nasal airflow. In many healthy subjects an alternating pattern of congestion and decongestion of the nasal passages is observed. Some individuals demonstrate congestion of the ipsilateral half of the nasal cavity when lying down on the side. Nasal diseases, including structural anomalies and various forms of rhinitis, tend to increase nasal resistance, which typically impairs breathing via the nasal route in recumbency and during sleep. A role of nasal obstruction in the pathogenesis of sleep-disordered breathing has been implicated by many authors. While it proves difficult to show a relationship between the degree of nasal obstruction and the number of disturbed breathing events, the presence of nasal obstruction will most likely have an impact on the severity of sleep-disordered breathing. Identification of nasal obstruction is important in the diagnostic work-up of patients suffering from snoring and sleep apnea.     

Alcohol, snoring and sleep apnea.

We studied the effect of alcohol ingestion on sleep-induced breathing abnormalities and arterial oxyhaemoglobin saturation in seven patients with a range of sleep-induced upper airway occlusion. The characteristics of each patient's sleep-induced breathing abnormality was established on one or more control all-night studies, and then a further all-night study was done immediately following alcohol ingestion. Alcohol increased the duration and frequency of the occlusive episodes in five patients with obstructive sleep apnoea, and resulted in a marked increase in the degree of hypoxaemia in the first hour of sleep. In two patients with benign chronic snoring, alcohol induced frank obstructive sleep apnoea during the first hour of sleep. We suggest that the increased tendency to develop obstructive apnoea after alcohol is the result of alcohol-induced oropharyngeal muscle hypotonia, while the increased duration of obstructive apnea is the result of alcohol-induced depression of arousal mechanisms.     

Prolonged Apnoea with Severe Arterial Hypoxaemia Resulting from Complex Partial Seizures

Multi-channel tape-recordings of the EEG, breathing movements, arterial pulsed oxygen saturation and ECG were performed on a four-year-old child with a history of cyanotic episodes. These had started at nine months of age, resulted in cardiopulmonary resuscitation on unnumerable occasions, and were refractory to anti-epileptic medication. During each episode seizure activity appeared first, followed within a few seconds by sinus tachycardia, prolonged absence of inspiratory efforts and severe arterial hypoxaemia. As the seizure activity ended, breathing movements restarted and there was a gradual improvement in oxygenation.     

Obstructive sleep apnea syndrome or abnormal upper airway resistance during sleep?

Obstructive sleep apnea syndrome is well known by now, but, at both extremes of age, increased upper airway resistance may lead to clinical symptoms without complete apnea. Abnormal craniofacial features appear to be responsible for the very early appearance during childhood of increased upper airway resistance. In adults, snoring, often related to partial upper airway obstruction located in the pharynx, may be associated with changes in respiratory timing and intermittent arousal. Many treatments are currently available to deal with obstructive sleep apnea syndrome. It is important to recognize the location(s) of the upper airway obstruction before considering treatment and to evaluate the associated risk factors. Early recognition of factors involved in increased upper airway resistance may allow prevention, a more efficacious approach than treatment of an already developed syndrome.     

Oxidant stress and inflammation in the snoring child: confluent pathways to upper airway pathogenesis and end-organ morbidity

Snoring in children is increasingly being recognized as a highly prevalent condition, and indicates the presence of heightened upper airway resistance during sleep. In this paper, we present evidence to support the hypothesis that local inflammatory processes within the upper airway contribute to the pathophysiology of adenotonsillar hypertrophy and altered reflexes potentially leading to increased propensity for upper airway obstruction during sleep. Furthermore, the cumulative evidence supporting multiorgan morbidity for sleep-disordered breathing (SDB) is reviewed, and a unified hypothesis of a triple risk model proposing oxidative-inflammatory mechanisms as mediating the morbid consequences of SDB is presented. This hypothetical working model incorporates both dose-dependent disease severity components, as well as environmental and genetic elements of susceptibility.     

Complex insomnia: insomnia and sleep-disordered breathing in a consecutive series of crime victims with nightmares and PTSD.

BACKGROUND: Sleep disturbance in posttraumatic stress disorder is very common. However, no previous posttraumatic stress disorder studies systematically examined sleep breathing disturbances, which might influence nightmares, insomnia, and posttraumatic stress disorder symptoms. METHODS: Forty-four consecutive crime victims with nightmares and insomnia underwent standard polysomnography coupled with a nasal pressure transducer to measure airflow limitation diagnostic of obstructive sleep apnea and upper airway resistance syndrome. RESULTS: Forty of 44 participants tested positive on objective sleep studies based on conservative respiratory disturbance indices of more than 15 events per hour; 22 patients suffered from obstructive sleep apnea and 18 suffered from upper airway resistance syndrome. CONCLUSIONS: In an uncontrolled study, insomnia and sleep-disordered breathing were extremely prevalent in this small and select sample of crime victims. Research is needed to study 1) prevalence of sleep-disordered breathing in other posttraumatic stress disorder populations using appropriate controls and nasal pressure transducers and 2) effects of sleep treatment on posttraumatic stress symptoms in trauma survivors with comorbid obstructive sleep apnea or upper airway resistance syndrome. In the interim, some posttraumatic stress disorder patients may benefit from sleep medicine evaluations.     

Sleep-related breathing disorder in children with vagal nerve stimulators

The effects of vagal nerve stimulation on sleep-related breathing have not been well-described in children. Vagal nerve stimulation was reported to cause decreases in airflow during sleep, although most studies reported this condition to be clinically insignificant. We present a retrospective case series of nine children who underwent polysomnography after vagal nerve-stimulator placement. All children, except for one, had sleep-disordered breathing after stimulator implantation. We describe in further detail a child who manifested severe, obstructive sleep apnea postimplantation, with apneas occurring regularly and consistently with stimulator activity, resulting in an elevated apnea-hypopnea index of 37 per hour. Polysomnography was repeated with the stimulator turned off, and revealed complete resolution of the stimulator-related sleep apnea. With the vagal nerve stimulator back on, continuous positive airway pressure treatment was effective in normalizing the apnea-hypopnea index. This study demonstrates that severe and clinically significant disturbances in sleep-related breathing may occur with vagal nerve stimulators. Obstructive apneas of this severity, related to vagal nerve stimulators, were not previously described in pediatric patients. This effect on sleep-related breathing warrants further investigation and care in managing pediatric patients.     

Catecholamines and children obstructive sleep apnea: a systematic review

IntroductionObstructive sleep apnea (OSA) is the most common sleep-related breathing disorder in children and is characterized by recurrent total or partial upper airway collapse episodes during sleep. OSA is associated with cardiovascular, metabolic and neurobehavioural complications related to sympathetic nervous system (SNS) activation. A key role in originating these complications and in underlying pathophysiologic mechanisms can be attributed to altered catecholamines (CAs) metabolism.MethodsA systematic review was performed according to the PRISMA Statement guidelines for research studies correlating OSA in children with catecholamines.ResultsOnly 13 studies out of 151 reports were included in the review. Most studies (9 out of 13) showed increased secretion for some catecholamines in patients with a sleep-related breathing disorder or OSA compared to a control group or post treatment control group.ConclusionOSA can activate the sympathetic nervous system (SNS) and increase catecholamines (CAs) production, perhaps contributing to increased morbidity. However, underlying pathophysiologic mechanisms remain still unclear.     

Behavior and Neurocognitive Performance in Children Aged 5-10 Years Who Snore Compared to Controls

Sleep disordered breathing in children is a common but largely underdiagnosed problem. It ranges in severity from primary snoring to obstructive sleep apnea syndrome (OSAS). Preliminary evidence suggests that children with severe OSAS show reduced neurocognitive performance, however, less is known about children who snore but do not have severe upper airway obstruction. Participants included 16 children referred to the Ear, Nose and Throat/Respiratory departments of a Children’s Hospital for evaluation of snoring and 16 non-snoring controls aged 5-10 years. Overnight polysomnography (PSG) was carried out in 13 children who snored and 13 controls. The PSG confirmed the presence of primary snoring in seven and very mild OSAS (as evidenced by chest wall paradox) in eight children referred for snoring while controls showed a normal sleep pattern. To test for group differences in neurocognitive functioning and behavior, children underwent one day of testing during which measures of intelligence, memory, attention, social competency, and problematic behavior were collected. Compared to controls, children who snored showed significantly impaired attention and, although within the normal range, lower memory and intelligence scores. No significant group differences were observed for social competency and problematic behavior. These findings suggest that neurocognitive performance is reduced in children who snore but are otherwise healthy and who do not have severe OSAS. They further imply that the impact of mild sleep disordered breathing on daytime functioning may be more significant than previously realized with subsequent implications for successful academic and developmental progress.     

Behavior and neurocognitive performance in children aged 5-10 years who snore compared to controls

Sleep disordered breathing in children is a common but largely underdiagnosed problem. It ranges in severity from primary snoring to obstructive sleep apnea syndrome (OSAS). Preliminary evidence suggests that children with severe OSAS show reduced neurocognitive performance, however, less is known about children who snore but do not have severe upper airway obstruction. Participants included 16 children referred to the Ear, Nose and Throat/Respiratory departments of a Children's Hospital for evaluation of snoring and 16 non-snoring controls aged 5-10 years. Overnight polysomnography (PSG) was carried out in 13 children who snored and 13 controls. The PSG confirmed the presence of primary snoring in seven and very mild OSAS (as evidenced by chest wall paradox) in eight children referred for snoring while controls showed a normal sleep pattern. To test for group differences in neurocognitive functioning and behavior, children underwent one day of testing during which measures of intelligence, memory, attention, social competency, and problematic behavior were collected. Compared to controls, children who snored showed significantly impaired attention and, although within the normal range, lower memory and intelligence scores. No significant group differences were observed for social competency and problematic behavior. These findings suggest that neurocognitive performance is reduced in children who snore but are otherwise healthy and who do not have severe OSAS. They further imply that the impact of mild sleep disordered breathing on daytime functioning may be more significant than previously realized with subsequent implications for successful academic and developmental progress.     

Two cases of sleep-disordered breathing in climacteric

Abstract Two cases of sleep disordered-breathing in climacteric were reported. Polysomnography including esophageal pressure (Pes) measurement was performed. Case 1 was diagnosed as upper airway resistance syndrome. Case 2 was diagnosed as obstructive sleep apnea syndrome, while many episodes of upper airway resistance also existed. Hormone replacement therapy improved clinical symptoms, and in case 1, Pes nadir was improved but incidence of arousals which was induced by breathing disturbances was not significantly changed. Sleep disordered-breathing should be suspected as a cause of sleep disorder even in females, especially in climacteric age. Pes measurement and evaluation of arousals is required. Hormone replacement therapy may release the upper airway resistance.     

Pattern of upper airway obstruction during sleep before and after uvulopalatopharyngoplasty in patients with obstructive sleep apnea

Objective: To investigate the pre-and postoperative pattern of upper airway obstruction in obstructive sleep apnea (OSA) patients treated by uvulopalatopharyngoplasty (UPPP).Background: The response rate to UPPP in unselected OSA patients is generally about 50%.Methods: Intraluminal pressure measurements during sleep were employed to analyze the pattern of upper airway obstruction before and after surgery.Results: Ten patients with mild to moderate OSA (respiratory disturbance index 19.7 (16.9–27.5) events/hr underwent a full night polysomnography before and 114 (6 1–138) days after UPPP. UPPP resulted in a significant improvement in subjective snoring and daytime sleepiness, but did not significantly alter the severity of sleep-disordered breathing. Preoperatively, the major site of obstruction was located at the oropharynx in nine patients, seven of them had additional minor obstruction sites outside the oropharynx. Complete relief of upper airway obstruction was only observed in those two patients with collapse confined to the oropharynx.Conclusions: In unselected OSA patients, UPPP improved subjective snoring and daytime sleepiness but did not result in a significant improvement in RDI or sleep architecture. Our results emphasize the need for a pre-operative investigation of the upper airway during sleep to select patients with collapse confined to the oropharynx.     

The prevalence, anatomical correlates and treatment of sleep-disordered breathing in obese children and adolescents

The prevalence of childhood obesity is increasing worldwide. One of the obesity-related complications that has received increasing attention in recent years is sleep-disordered breathing. Obese children are at a higher risk of developing sleep-disordered breathing, including habitual snoring, obstructive sleep apnea syndrome and desaturations preceded by central apneas. Both adiposity and upper airway factors, such as adenotonsillar hypertrophy, modulate the severity of sleep-disordered breathing in these children. Adenotonsillectomy seems to be effective against obstructive sleep apnea syndrome in obese children. On the other hand, there are limited data on the effects of weight loss and of treatment with continuous positive airway pressure on the severity of sleep apnea in obese children and adolescents.     

Sleep-disordered breathing and behavior in three risk groups: preliminary findings from parental reports

Sleep-related breathing disorders may cause excessive daytime sleepiness, cognitive impairment, and behavior problems in children and adolescents. Adenotonsillar enlargement (AT) is known to be a significant risk factor for these disorders, which have also been reported in several patients with Down syndrome (DS). Children with attention deficit disorder/hyperactivity (ADD) show behavior problems that may be related to disturbed nocturnal sleep in some. To evaluate the relationships among these disorders and symptoms, parents of 29 school-aged children with AT, 70 with DS and 48 of their siblings (DS-SIB), and 21 with ADD completed a 20-item screening questionnaire covering nocturnal sleep symptoms and daytime behavior problems. Nocturnal symptoms of sleep-related breathing disorders — snoring, breathing pauses during sleep — were reported more commonly by parents of AT and DS children. However, parents of two of the ADD children reported significant signs of sleep-related breathing disorders. Daytime behavior problems were more common in ADD and AT than in the DS group. Bedwetting reports did not distinguish groups. Direct comparisons of DS and DS-SIB groups showed that more DS were mouth breathers, snored, stopped breathing at night, and were sleepy in the daytime. These findings underscore the importance of obtaining a history of nocturnal sleep from parents of children with AT and DS, as well as those with disrupted daytime behavior.     

Polygraphic investigation of respiration during sleep in infants and children.

Controls of respiration have different settings during sleep than during wakefulness. Respiration will also be influenced by sleep state organization and circadian rhythm. Polygraphic monitorings in infants and children must take into account the timing of the longest sleep and longest wakeful periods and the distribution of sleep states. Attention must be given not only to "apneas" and blood gas changes monitored noninvasively but also to breathing frequency, upper airway resistance, and the impact of respiratory changes on the cardiovascular system and sleep continuity. Respiratory efforts and upper airway resistance are responsible for important mechanical intrathoracic changes, which must be evaluated, since they have clinical consequences. For example, infants with an apparent life-threatening event may have an unrecognized increase in upper airway resistance long before having a mixed or obstructive sleep apnea. Muscle disorders in young children require regular sleep monitoring whose results will strongly influence therapeutic approaches. Therapy may change over time, depending on the prominence of the inspiratory muscle weakness or the importance of the mandibular abnormalities induced by the muscle disorder and its impact on upper airway resistance during sleep. At times, it is difficult to avoid sleep disturbances with aggressive investigation of breathing during sleep, and several successive days of monitoring may be needed to determine sleep-related pathology.     

The eye in sleep apnea syndrome

Sleep apnea syndrome (SAS) is a disease characterized by recurrent complete or partial upper airway obstructions during sleep. The majority of patients with SAS demonstrate this obstruction either at the nasopharynx or the oropharynx. Risk factors for SAS include obesity, male gender, upper airway abnormalities, alcohol use, snoring, and neck girth of more than 17 in. in men or 16 in. in women. Reported ophthalmic findings in patients with SAS include floppy eyelid syndrome (FES), glaucoma, and non-arteritic anterior ischemic optic neuropathy (NAION).     

Primary sleep apnoea syndrome.

Polygraphic study in 18 men with the sleep apnoea syndrome showed central, upper airway obstructive, and mixed apnoeas. Fifty per cent of the total apnoea time was central, 33% was obstructive, and 17% was mixed. Apnoeic episodes were accompanied by oxygen desaturation, relative bradycardia and hypotonia of orofacial muscles innervated by ponto-medullary neurons. During regular breathing these muscles revealed tonic and phasic inspiratory EMG activities. The data suggest that the primary sleep apnoea syndrome results from a dysfunction of the central control of breathing.