Sleep-related breathing disorders (SRBD) is a common and frequent disease with a prevalence of 2-4% in adults, 20-40% in people over 65 years old, and 6-10% in children. Snoring is a typical symptom of SRBD. In the past, the public thought that snoring was a sign of good sleep quality, but in fact, snoring is a sign of weakened breathing during sleep, and loud, intermittent intermittent snoring is a sign of sleep apnea invasion, which should be recognized and paid more attention to.
SRDB can not only lead to nocturnal sleep snoring, apnea, daytime drowsiness and hypoxemia, thus causing reduced work efficiency and quality of life, but also participate in the development of hypertension, cardiovascular disease and type II- diabetes as a source pathogenic factor, and is closely related to stroke and sleep stroke death. Epidemiological investigations have shown that untreated sleep apnea leads to a significant increase in the risk of cardiovascular events, suggesting that SRDB can also cause death. Data show that a patient with sleep apnea is seven times more likely to have a stroke than a patient without sleep apnea, that more than half of patients with congestive heart failure have obstructive sleep apnea, and that 58% of patients with type II diabetes also have obstructive sleep apnea. Patients with obstructive sleep apnea are more than seven times more likely to have a traffic accident than normal people.
In recent years, research on sleep apnea disorders has developed rapidly and many new concepts have emerged, which are introduced here to let more public understand this disease and thus improve the quality of life of the public.
1.Classification of common SRBD
SRBD is a generic term for a group of diseases. Common sleep breathing disorders include: snoring or primary snoring (PS), upper airway resistance syndrome (UARS), sleep apnea-hypopnea syndrome (SAHS), and obesity hypoventilation syndrome; SAHS), obesity hypoventilation syndrome (OHS), and over-lap syndrome.
The most typical symptom of these diseases is snoring, with different snoring characteristics and different sleep quality, with or without morning fatigue, headache and daytime sleepiness.
Snoring (PS) manifests as sleep snoring with more uniform and rhythmic snoring, no obvious apnea, no repeated micro-awakenings during sleep, and no accompanying sleep hypoxia; therefore, the quality of sleep is still good, and no manifestations such as morning fatigue, headache and daytime sleepiness will occur. Snoring suggests the presence of narrowing of the upper airway during sleep and should be treated promptly to eliminate its cause and avoid further development of the disease.
The snoring characteristics of upper airway resistance syndrome (UARS) are more similar to snoring, but there are repeated micro-awakenings during sleep, so many patients have daytime drowsiness and fatigue due to decreased sleep quality at night. These micro-awakenings are difficult to be detected by patients and family members, and can only be detected by a professional instrument – polysomnogram (PSG). Therefore, patients should go to the hospital for professional screening in time for clear diagnosis and timely treatment.
The snoring in sleep apnea-hypoventilation syndrome (SAHS), on the other hand, is different from the above two types of diseases. It is characterized by a change in the rhythm of snoring, the existence of ups and downs in the sound and obvious pauses, usually accompanied by frequent micro-awakenings and even awakenings, and repeatedly reduced blood oxygen saturation. As a result, the patient’s sleep quality is poor, and nighttime sleep does not allow the heart, brain and other systemic systems to recuperate and recover, and the patient may feel self-conscious of morning fatigue, headache and daytime drowsiness, memory loss and difficulty in concentration. There are three types of sleep apnea-hypoventilation syndrome: obstructive (OSAHS), central (CSAHS) and mixed (MSAHS); among them, OSAHS is the most common. When the disease has progressed to this stage, timely treatment is essential, as the repeated occurrence of apnea prevents the person from obtaining sufficient oxygen, and carbon dioxide excretion also stops, the body’s organs and tissues must suffer from different degrees of functional damage or even cell death, so long-term sleep hypoxia can lead to various cardiovascular and cerebrovascular complications, and is a high risk factor for hypertension and stroke.
Obesity hypoventilation syndrome (OHS), also known as Pickwickian syndrome, is a group of sleep breathing disorders with severe signs and symptoms. This disease is associated with obesity, patients have frequent pauses in snoring, sleep is the presence of severe sleep apnea or hypoventilation, repeated awakenings or micro-awakenings; both day and night hypoxemia and hypercapnia, systemic organs are in a prolonged hypoxic state, which is extremely harmful to all systems of the body. Its treatment should be based on symptomatic treatment of the cause, control obesity and reduce body weight in order to achieve a better prognosis.
Overlap syndrome: the overlap of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea hypoventilation syndrome. Therefore, the underlying pulmonary disease should be actively treated along with the treatment of sleep disordered breathing disease.
2.Diagnosis of SRBD
Polysomnogram (PSG) is currently the internationally and nationally recognized gold standard for the diagnosis of sleep disordered breathing disorders. In addition to EEG, the current formal PSG monitoring should include ECG, EMG, oculogram, thoracic and abdominal respiratory tension, nasal and oral ventilation, postural movement, oxygen saturation and other physiological signals of more than 10 channels, which enable physicians to comprehensively understand the conditions of patients during sleep and clarify the type and degree of sleep disordered breathing. The results are expressed as the Apnea Hypopnea Index (AHI), which indicates the average number of apneas and hypoventilations (hypoventilation) per hour of sleep.
With the further development of monitoring devices, sleep monitoring has been expanded, accuracy has been further improved, and analysis techniques have become easier. Particularly noteworthy is the introduction of esophageal manometry, the application of which and integration with polysomnographic monitoring systems plays an important role in determining the site of upper airway obstruction during sleep in patients and is of guiding importance for surgeons in the development of surgical plans.
PSG is an important instrument for the diagnosis of sleep-related breathing disorders, but only the PSG test indicators are incomplete; AHI is only an indicator of sleep breathing disorders, and the so-called syndrome must have corresponding clinical symptoms and signs as a reference for diagnosis.
In April 2002, the Respiratory Diseases Group of the Chinese Medical Association issued a draft guideline for the diagnosis and treatment of obstructive sleep apnea hypoventilation syndrome; in December 2002, the Otolaryngology Branch of the Chinese Medical Association released the criteria for diagnosing and evaluating the efficacy of obstructive sleep apnea hypoventilation syndrome and the indications for uvulopalatopharyngoplasty. The criteria are: AHI/RDI 5~15, 90%~85% of minimum blood oxygen during sleep is mild; AHI/RDI>15 and ≤30, 85%~80% of minimum blood oxygen during sleep is moderate; and AHI/RDI>30, <80% of minimum blood oxygen during sleep is severe.
Sleepiness is a common manifestation of sleep apnea disorders, and the evaluation of the severity of sleepiness is generally divided into subjective and objective evaluations. The subjective evaluation is mainly based on the Epworth Sleepiness Scale (ESS) and the Stanford Sleepiness Scale (SSS), which are mostly in the form of questionnaire scores and are highly operational.
The objective evaluation of narcolepsy is based on the multiple sleep latency test (MSLT) by applying PSG to the patient, which allows the patient to take a series of naps during the day to objectively determine the degree of daytime sleepiness. The test results should be combined with nighttime monitoring to more accurately determine the extent of the patient’s condition.
3.Treatment of SRBD
At present, the internationally recognized treatment methods are mainly divided into surgical treatment and non-surgical treatment, among which surgical treatment is divided into different procedures according to the patient’s disease typology, obstruction location and disease degree, including UPPP (Uvulopalatoplasty), bimaxillary advancement, bimaxillary traction, etc.; while non-surgical treatment can be divided into Continuous Positive The non-surgical treatment can be divided into Continuous Positive Airway Pressure (CPAP) and Oral Appliance (OA) treatment, etc.
4.How to choose the treatment plan?
The treatment plan for sleep disordered breathing needs to be determined based on the type and severity of the patient’s disease, the patient’s age and health status, the patient’s wishes and the medical institution’s level of care.
In general, surgery is preferred for SRBD caused by facial skeletal deformities; facial skeletal deformities, the technical term for jaw deformities, i.e., small chins, shoe-pulled faces, etc., which are common in life, can affect the morphology and function of the upper airway due to the abnormal morphology and position of the maxilla or mandible, therefore, correction and reconstruction of jaw deformities can not only restore the patient’s craniomaxillofacial morphology and Therefore, the correction and reconstruction of jaw deformity not only can restore the craniofacial morphology and related functions of patients, but also can completely relieve SRBD caused by upper airway stenosis, which is the treatment of choice for such SRBD; at the same time, the improvement of jaw and facial morphology is also extremely helpful to the psychology of adolescent and child patients, and can achieve good treatment results. Our Academician Qiu Yiliu pioneered the mandibular advancement surgery in the 1970s to treat sleep apnea caused by temporomandibular joint ankylosis, which not only greatly improved the survival quality of patients, but also improved their appearance and restored their self-confidence. And with the development and maturity of a series of techniques such as orthognathic surgery and traction osteogenesis, such surgery can obtain stable, long-lasting and good results, and take into account the patient’s sleep, appearance and chewing function, so that the patient can regain his or her life.
SRBD with non-maxillary deformities as the main cause, such as obesity, requires a treatment plan based on the severity of the patient’s disease, the location and nature of the obstruction, the patient’s age and health status, and the patient’s wishes. Different locations and degrees of obstruction in the upper airway require different surgical options; multilevel obstruction requires associated surgical combination; and severe patients require comprehensive, sequential treatment measures.
For patients with SRBD in which non-maxillary deformity is the primary cause, various aspects such as the patient’s age, type of disease, severity, and patient’s wishes need to be considered. In general, surgical treatment is preferred for young and middle-aged patients, and non-surgical treatment is preferred for immature and elderly patients; mild and moderate patients can be treated surgically first, because a single or simpler surgery can greatly relieve sleep breathing disorder in these patients; while non-surgical treatment means, such as CPAP treatment, are preferred for severe patients, because simple surgery is hardly ideal to relieve their sleep breathing disorder. Of course, if there is a strong desire for surgery and an obvious indication for surgery, patients without contraindications to surgery can also be treated well with sequential surgical treatment. For patients who have obvious indications for surgery but are hesitant and fearful of surgical treatment, unless they have obvious obstructive factors in the upper airway and can be lifted by simpler surgery, they should generally comply with the patient’s wishes and use non-surgical conservative treatment first. In addition, the general principle is to strictly grasp the indications for surgery and whether it is within the ability of the medical institution and physician’s level of treatment.
5.How to determine the location and nature of obstruction?
Sleep obstruction of the upper airway is the cause of the disease. Early studies emphasized the influence of anatomical and morphological abnormalities on sleep breathing, but nowadays the influence of the dysfunction of the open airway muscles is getting more and more attention from the medical community.
Previous methods of assessing upper airway obstruction include X-ray cephalometric analysis, nasopharyngeal fiberoptic endoscopy, CT and MR examinations. These examinations are done while the patient is awake and ignore the role of central nervous and upper airway neuro-muscular functional factors that regulate sleep breathing and upper airway muscle tissue activity in maintaining upper airway opening. To compensate for its deficiencies, we used a combination of cephalometric analysis and PSG monitoring results, which can determine the patient’s upper airway stenosis, the site of obstruction, and its functional factors.
In addition, the esophageal pressure test method can greatly improve the accuracy of the diagnosis of the location of upper airway obstruction. It can show the site and dynamic changes of upper airway stenosis or obstruction occurring during the patient’s sleep in real time, which integrates the results of the morphological and functional factors of the upper airway acting together during the patient’s sleep. The majority of patients with obstructive sleep apnea have morphological or structural abnormalities of the craniomaxillofacial region. Therefore, how to accurately determine and grasp the site of upper airway obstruction is of guiding significance for the development of treatment plan.
6.Can I choose surgical treatment for obese SRBD?
Obesity is the most common cause of SRBD, and the prevalence of obese SRBD is much higher than that of SRBD due to jaw deformity. Obesity and related diseases are one of the serious challenges faced by human beings in this century. The generally accepted treatment principle for these obese patients with severe SRBD is sequential comprehensive treatment: (i) weight loss and weight gain control. ② Local staged surgery: Phase I for nasal obstruction correction, such as nasal polyp removal, nasal septum deviation correction, UPPP, hyoid suspension, and radiofrequency temperature-controlled reduction treatment of hypertrophied turbinates, tonsils, soft palate and tongue root. In the second stage, such as linguoplasty, lower/upper jaw advancement and bimaxillary advancement are performed. Positive pressure ventilation is used during phase I and II treatment. If the patient’s sleep breathing disorder becomes mild or moderate after phase I treatment, it can be combined with radiofrequency temperature-controlled decompression therapy or oral appliance therapy.
These procedures can be seen as a local “weight loss” means, for obese patients, the fundamental treatment measures or overall weight loss. Because even bimaxillary advancement may not be enough to lift the upper airway obstruction in super obese patients. In recent years, foreign introduction of body mass index (body mass index, BMI) ≥ 40, after conservative treatment is ineffective and exclude endocrine disorders caused by serious obesity patients can carry out “surgical weight loss”, currently commonly used surgical weight loss surgery are: ① jejunoileal short-circuit (Jejunoileal) bypass) or called small bowel bypass (Small bowel bypass). ② gastric bypass rerouting (Gastric bypass). ③gastroplasty (gastroplasty). ④The partial biliopancreatic bypass. The design principles of these procedures can be broadly summarized as: (i) restriction and reduction of food intake; (ii) rapid passage to reduce nutrient absorption, and (iii) reduction of digestive enzymes leading to malabsorption of nutrients.
It has been reported that patients can lose approximately 65% to 80% of their excess body weight (beyond the ideal portion of their body weight) at 12 to 18 months after surgery, a reduction of approximately 10 kg/m². Combined with a slight rebound, a total reduction of approximately 50-60% of excess body weight can be observed in the long term. Moreover, the degree or symptoms of obesity-related diseases have also improved, with reports showing that about 90% of type II diabetes is almost completely cured after surgery, and about 2/3 of hypertension disappears 4 years after surgery, etc.
Patients with obstructive sleep apnea syndrome respond particularly well to bariatric surgery, with symptoms improving significantly or disappearing after an early weight loss of 15 to 20 kg, and often completely cured.
7. Can surgery solve everything?
Many patients hope to treat SRDB quickly and effectively through surgery, but not all patients are suitable for surgery. Therefore, the type, severity, location, nature and degree of upper airway obstruction, as well as the craniofacial deformity of the patient must be clarified before surgical treatment, and it is especially important to choose a suitable and effective surgical procedure to eliminate the abuse of surgery for the treatment of this disease.
Currently, the most internationally recognized surgical procedures include UPPP (Uvulopalatoplasty of the soft palate), radiofrequency temperature-controlled volume reduction therapy and plasma therapy, as well as bimaxillary advancement.
UPPP has been greatly promoted in the treatment because of its easy operation, small trauma and fast postoperative recovery, but according to the available data, its efficiency is only 50%. The reason for this is that the indication of surgery is the key to the success of treatment. This surgery is the basic procedure to lift palatopharyngeal stenosis, which is suitable for mild to moderate OSAHS. One of the common complications of the surgery is voice alteration, which can cause palatopharyngeal closure insufficiency in severe cases and affect the quality of life of patients, and abuse needs to be prevented. Our hospital has improved the success rate and significantly reduced this complication by using computer-aided design of the surgical protocol.
In contrast, radiofrequency temperature-controlled volume reduction therapy or plasma therapy is only an effective treatment for PS, UARS and mild OSAHS, and is not a panacea. In severe patients, it is only an adjunctive treatment, and if repeatedly applied inappropriately, it can instead cause complications such as local scar hyperplasia, soft palate perforation, and empty nose syndrome, and should not be abused.
In addition, for patients with SAHS with non-morphological factors and upper airway neuro-muscular dysfunction as the main cause, such as CSAHS, surgical treatment is not indicated. In this regard, it is important to point out that different sites and degrees of stenosis and obstruction require different surgical methods to lift them; a good grasp of surgical indications and surgical methods is the key to successful surgical treatment, and blindly treating all patients with a single method or procedure will have predictable results.