Since August 1, 2012, the Department of Pediatrics, the Department of Respiratory Medicine and the Department of Otolaryngology of Shanghai Children’s Medical Center have been conducting a joint sleep clinic for children every Wednesday afternoon to focus on sleep disorders in children and to better serve children’s health.
Every person has two physiological states: awake and asleep. Sleep is an important physiological process for wakefulness, which is the creation, development and maintenance of the consciousness of the living body. Only when the life activities in both states of wakefulness and sleep are carried out normally, can a human individual with a healthy body and a healthy mind be created, which can sensitively perceive various changes in the external environment and produce corresponding reflex activities to adapt to various changes in the environment. If there is a sleep disorder or a long period of partial deprivation of sleep, the nerve cells of the brain will have to continuously carry out activities, which will lead to the central nervous system, especially the cortical activity of the brain malfunction, the mental activity capacity is reduced, various reflexes are weakened, and even abnormal behavior, and the growth and development of people, the efficiency of activities will be seriously affected.
Current research has found that poor sleep can cause children to experience relatively delayed growth and development, impaired multi-system functions such as immunity, attention, memory, organization, creativity and motor skills, and behavioral and emotional problems. Sleep disorders affect children in three main ways.
1. Low cognitive function: Sleep deprivation can lead to low neurocognitive function because it affects the breadth of attention, memory and the ability to think abstractly. In children of all ages, sleep deprivation also increases the risk of accidents.
2. Behavioral problems: Some studies have found that sleep problems in infancy can continue into early childhood, and such children will have more sleep as well as behavioral problems when they are slightly older compared to children who sleep well, which can also cause a range of emotional behavioral problems, such as daytime sleepiness, aggressiveness, hyperactivity, irritability, impulsiveness, inattention, excessive crying, temper tantrums, poor self-control, and other more severe symptoms.
3. Physical development: Sleep problems can disrupt the secretion of growth hormone during deep sleep, which affects the endocrine and metabolic systems of children. Their immune system is also threatened and their physical growth and development is affected.
In order to ensure a good quality of sleep for children to ensure a healthy physical and mental development, it is necessary to carry out an in-depth study of this sleep medicine, in which some issues should be given special attention.
First of all, sleep disorders occurring in children at different ages are different and are closely related to different ages and developmental stages.
1, infancy: mainly it is difficult to establish a stable sleep pattern, forming behavioral insomnia, sleep disturbance, manifested as difficulty in falling asleep and continuing sleep, which can last until early childhood or even late childhood. The main reason for this is that the important stage of sleep development in children from 8 to 12 weeks after birth has not been paid attention to, and the diurnal sleep cycle has not been well established, and the ability to “self-soothe” in the sleep/wake cycle has not been developed in behavioral development.
2. Early childhood: Night terrors, somnambulism and sleep walking disorder are common. Some studies suggest that night terrors may occur in the middle of the interaction between biological factors, environmental factors and the child’s cognitive development, while somnambulism and somnambulism are mostly related to the immature development of the central nervous system.
3. 4-9 years old: prone to frequent snoring during sleep, teeth grinding disorder and nightmares. The causes are mostly related to the physiological growth spurt of lymphoid tissues (adenoids, tonsils, etc.) in the pharynx during this age, the narrowing of the airway, the eruption of permanent teeth instead of milk teeth, and the immaturity of the development of the central nervous system during this period.
4, after the age of 10 to adolescence: more sleep deprivation, insomnia and episodic sleeping sickness. The incidence of insomnia in adolescence is 10-20%, mostly due to environmental influences that disrupt the endogenous rhythmic cycle that regulates the sleep-wake cycle.
Common sleep disorders include sleep-related disorders, food allergy insomnia, nocturnal feeding syndrome, circadian rhythm disorders, obstructive sleep apnea syndrome, episodic sleep disorder, enuresis, etc. We will focus on obstructive sleep apnea syndrome.
Obstructive sleep apnea syndrome (OSAS) in children refers to a series of pathophysiological changes caused by frequent partial or total upper airway obstruction during sleep, which disrupts normal ventilation and sleep architecture in children.
The key to the development of obstructive sleep apnea is the collapse of the pharyngeal airway during sleep. The site of airway obstruction can be in the nasopharynx, oropharynx, and laryngopharynx, and in more than 80% of patients it is a combined oropharyngeal and laryngopharyngeal obstruction. Causes of upper airway obstruction are both anatomical abnormalities (enlarged tonsils and adenoids, local malformations, etc.) and functional defects. They both act by increasing the collapsibility of the pharyngeal airway and affecting the contrast between its opening and closing forces. The etiology includes common diseases (otitis media, sore throat and tonsillitis), allergic reactions, obesity, recession of the jaw and cleft palate, as well as any factor that can cause more effort to inhale the gas.
According to surveys the incidence of the disease is 1.0-7.1% in European countries; 1.3%-4.2% in Japanese; 3.4% in China (possibly up to 7%-13%).
The symptoms of sleep apnea are many. The most significant symptoms are snoring and dyspnea during sleep, often manifested as apnea for a few seconds, but also as breathing through the mouth most of the time (at night and during the day), abnormal chest and abdominal reverse breathing, frequent coughing or choking at night, restlessness, excessive sweating, loss of urine, night terrors or nightmares, and also sleepwalking. During the day, it often manifests as morning headache, sleepiness, irritability, nasal congestion, poor concentration, and recurrent upper respiratory tract infections.
OSAS leads to nocturnal hypoxia and hypercapnia, which can cause pulmonary hypertension, right heart failure and pulmonary heart disease if the attacks are frequent or last too long. Hypoxic attacks can also cause bradycardia, arrhythmia or even cardiac arrest and hypoxic convulsions. Long-term chronic hypoxia can interfere with cerebral energy metabolism, causing restless sleep at night and frequent nocturnal awakenings, resulting in neurobehavioral changes; it can also cause relative growth hormone deficiency, while unfavorable swallowing and chewing can cause malnutrition. As a result, children with prolonged OSAS may have signs of stunted growth, hypertension, enlarged heart, right heart failure and pulmonary heart disease. In addition, obstruction of the pharynx makes the child breathe through the mouth to reduce resistance, and prolonged open-mouth breathing can cause malformation of the maxillofacial development; due to the reduction of intrathoracic pressure caused by forceful inspiration, frequent awakening and frequent tossing can also cause gastroesophageal reflux.
Diagnostic methods, core assessment of OSAS can be performed by various laboratory tests.
Polysomnography (PSG) is the most important diagnostic tool for sleep breathing disorders, the gold standard for diagnosing sleep disorder diseases and an objective indicator for efficacy evaluation, which can determine the type of sleep breathing disorders (such as simple snoring, upper airway resistance syndrome and central or obstructive sleep apnea syndrome, etc.) and their severity, and if necessary, pressure adjustment for continuous positive pressure ventilation therapy.
The recommended diagnostic criteria for OSAS in children at the Sleep Center of Beijing Children’s Hospital are.
① apnea ≥ 5 seconds or more than 2 respiratory cycles.
② apnea index (AI) ≥ 1 breath/hour, hypoventilation is diagnosed by a 50% decrease in the amplitude of oral and nasal airflow from baseline (baseline refers to the average amplitude of breathing for at least 2 minutes or 3 respiratory cycles before airflow stops or decreases) for more than 5 seconds or 2 respiratory cycles, accompanied by a decrease in blood oxygen saturation of 0.03 or more or arousal.
Apnea hypoventilation index AHI ≥ 5 breaths/hour is diagnosed as OSAS in children
AHI 5-10 breaths/hour was considered mild; 11-20 breaths/hour was considered moderate and more than 20 breaths/hour was considered severe.
Frontal and lateral nasopharyngeal X-ray: adenoid hypertrophy obstructs the nasopharyngeal airway, and tonsillar hypertrophy and soft palate enlargement aggravate the obstruction of the palatopharyngeal airway; low and anterior hyoid bone is also a cause of snoring.
The nasopharyngeal X-ray frontal and lateral radiographs can better measure the upper airway and its surrounding structures, which is of great value in the study of the upper airway structure in children with snoring.
Pulmonary function: In the study conducted on the correlation between children’s sleep snoring with different states including apnea/hypoventilation and pathological changes in pulmonary function, it was found that most children with persistent snoring with a history of apnea for more than one year may cause pathological changes in pulmonary function, and this pathological change in pulmonary function may cause hypoxia in the body, especially long-term chronic hypoxia in the brain, which affects the intelligence, learning ability and memory of the children. There are individual cases where the degree of snoring is inconsistent with the results of pulmonary function tests, and this phenomenon may explain why children with light snoring obstruction (AHI) have a severe decrease in blood oxygen saturation (SaO2).
In future diagnostic criteria, three objective indicators will be used: blood oxygen saturation (SaO2) and oronasal airflow (AHI/AI), and tidal volume/inspiration/expiration ratio/peak time ratio to determine the mild, moderate or severe degree of OSAS, so it is important to perform the assessment of pulmonary function.
Cognitive function assessment: Sleep disorders are a multi-organ, multi-system and multi-disciplinary disease. Numerous clinical observations have shown that children with OSAS have significant cognitive impairment, which imposes a heavy burden on society and families. cognitive impairment in OSAS patients is mainly manifested in general intelligence, attention, concentration, memory (including fragmentary and procedural), alertness, and executive function.
Once OSAS is diagnosed, how is it treated?
The principles of OSAS treatment in children are early diagnosis and treatment, removal of upper airway obstructive factors, and prevention and treatment of complications. Surgery is the main method of treatment for OSAS in children, depending on the location and cause of the obstruction
I. Surgical treatment – adenoidectomy + tonsillectomy (T&A)
1. Indications for surgical treatment.
(1) Children with OSAS caused by enlarged tonsils and adenoids
(2) Simple snoring with recurrent tonsillar inflammation and/or chronic inflammation of adenoids
2. T&A surgical methods: including plasma ablation, electrocoagulation cutting, tonsil peeling, adenoid scraping, and nasal endoscopic power system cutting (adenoids). For details, please consult a physician specializing in the five gynaecological departments.
II. Non-surgical treatment
(I) Non-invasive positive pressure ventilation (NIV)
1.Types of NIV ventilation mode
(1) Continuous positive airway pressure ventilation (CPAP)
(2) Auto-regulated continuous positive airway pressure ventilation (Auto-CPAP)
(3) Bi-level positive airway pressure ventilation (BiPAP)
2.The working principle of NIV is to provide a physiological pressure support for the child via the nasal cavity to ensure the opening of the upper airway during sleep. This is done by applying electronic devices to provide continuous airway pressure above atmospheric pressure through the nasal mask in both the inspiratory and expiratory phases of the respiratory cycle, which causes passive expansion of the airway and increases alveolar ventilation to ensure a clear airway during sleep in children with OSAS.
3. Indications for NIV
(1) Presence of contraindications to surgical procedures
(2) Children with small tonsils and adenoids or OSAS after tonsil or adenoidectomy and those who choose non-surgical treatment
(3) Perioperative treatment of children with high-risk factors for OSAS. Home noninvasive positive pressure ventilation is a very important treatment for children with high-risk factors for OSAS.
High-risk factors for OSAS: infants and children with craniofacial anomalies, Down syndrome, cerebral palsy, neuromuscular disease, chronic lung disease, streptocytosis, central hypoventilation syndrome, and systemic metabolic storage disease.
(ii) Weight loss
Obesity affects sleep: the accumulation of fatty tissue around the airway in obese people can compress the airway and significantly reduce the internal diameter of the upper airway. Due to the accumulation of fat in the mucous membrane of the oropharynx and the subcutaneous accumulation of the neck, the upper airway is narrowed. Because of the obese children’s thoracic and abdominal cavity wall hypertrophy, the accumulation of abdominal fat causes the diaphragm to move upward, the lung capacity decreases, and the respiratory movement is restricted, so that many obese patients are panting and sweating when they move a little. The purely obese person itself exists in the waking state to reduce lung function, manifesting as ventilation deficiency, airway resistance is elevated, further aggravating the symptoms in the supine position, making the airway collapse further increase, more likely to cause airway obstruction.
(iii) Drug treatment
Pharmacological treatment of allergic rhinitis Severe nasal congestion, clear runny nose and frequent cough induce and aggravate OSAS in children and can trigger asthma, which has seriously affected children’s breathing, learning, cognitive ability and normal life. This requires timely diagnosis and treatment by a specialist. Specific medications include sodium cromoglycate, colecalciferol, endosulfan and other drugs, which are chosen according to the interval between attacks and the degree of exacerbation in children. Through treatment, nasal resistance can be reduced, nasal ventilation can be improved, and negative pressure in the pharynx during inspiration can be lowered to reduce and treat OSAS.
(iv) The use of oral orthodontic appliances
It is mostly used for those whose jaw development has been basically completed. The use for children with mild or moderate small jaw OSAS who cannot be operated or cannot tolerate CPAP treatment needs to be decided by a dentist.
(E) Sleep guidance such as adjustment of sleep position
There are many elements of sleep instruction, mainly for different children in terms of sleep environment, feeding, and sleep hygiene habits.
For children with OSAS, sleep position is particularly relevant. Experts recommend adopting a lateral position as much as possible and, if necessary, sewing a small elastic ball-like object on the back side of the child’s pajamas to help control the correct sleep position and reduce the chances of supine lying. Sometimes treatment is difficult to adhere to and requires parental cooperation.
Finally, let’s look at a classic case of a child with obstructive sleep apnea syndrome
Parental question: “Every night, my son, Pengpeng, often stops breathing and each time it lasts so long that I worry if he will breathe again. To make it easier to wake him up, I let Pengpeng sleep with me. Some time ago, there were a few nights when Pengpeng’s breathing stops were significantly longer again, but when I took him to the doctor, he said he was fine.”
Guidance: Sleep apnea is a serious sleep disorder, mainly manifested by recurrent episodes of apnea and hypoventilation during sleep. Previously, sleep apnea was thought to occur mostly in adults, but in fact, 1-3% of children are also accompanied by apnea, with a high prevalence in ages 2-6. Many parents are currently unaware that their child has apnea, and some, like Pengpeng’s mother, do not know where to go for help, even though they have noticed that their child has apnea.
The most noticeable symptoms in children with sleep apnea are snoring and difficulty breathing during sleep, often manifested as pauses in breathing for a few seconds, but also as breathing through the mouth most of the time (at night and during the day), abnormal chest and abdominal reverse breathing, abnormal sleep positions, frequent coughing and choking at night, restlessness, excessive sweating, loss of urine, night terrors or nightmares. During the day, they often present with morning headaches, excessive sleepiness, sleepiness, and many abnormalities: inappropriate behavior, irritability, hyperactivity, sudden personality changes, feeding difficulties, growth retardation; and decreased academic performance in older children. In addition, some studies have found that attention-deficit/hyperactivity disorder (ADHD) and sleep apnea are highly correlated, with 25% of children with ADHD having sleep apnea. These values do not mean that children with ADHD have apnea, but these children need to be specifically screened.
There are many causes of sleep apnea, starting with adenoids and tonsillar hypertrophy, as well as common diseases (otitis media, sore throat and tonsillitis), allergic reactions, obesity, decreased muscle tone, receding jaw and cleft palate. When apnea is suspected, the child should be taken to a sleep medicine specialist or otolaryngologist and a physical examination and complete nighttime sleep monitoring should be recommended.
For most children, removal of enlarged adenoids and tonsils is the preferred treatment option, and once the mass is removed, apnea symptoms quickly disappear. In some children, airway obstruction is due to nasal polyps or non-corresponding local structures of the oropharynx, and appropriate excisional or maxillofacial orthopedic surgery may be performed. If the child’s apnea is related to allergies or asthma, treatment is required in consultation with a pulmonologist or allergist. In obese children, weight loss is also an effective treatment. In addition, the treatment method of continuous positive airway pressure (CPAP), which was previously commonly used for apnea in adults, is gradually beginning to be applied to children, but care should be taken to follow up regularly during its use, as CPAP requirements and pressure levels need to vary according to the child’s growth and development.