Sleep apnea hypoventilation syndrome is defined as recurrent episodes of apnea more than 30 times per night during sleep or sleep apnea hypoventilation index (AHI) ≥ 5 times/hour with clinical symptoms such as drowsiness. Apnea is the complete cessation of oral and nasal airflow for more than 10 seconds during sleep; hypoventilation is the reduction of respiratory airflow intensity (amplitude) by more than 50% from the basal level during sleep, and is accompanied by a decrease in blood oxygen saturation by ≥4% from the basal level or microarousal; sleep apnea hypoventilation index is the number of apnea plus hypoventilation per hour of sleep time. There are three types: central (CSAS), obstructive (OSAS), and mixed (MSAS).
Central sleep apnea syndrome (CSAS)
CSAS alone is less common and generally does not exceed 10% of apneic patients, with some reports of only 4%. The ventilation can be further divided into two main categories: hypercapnia and normocapnia. It can coexist with obstructive sleep apnea syndrome, and most have neurological or motor system pathology. The pathogenesis may be related to the following factors: 1) reduced responsiveness of the respiratory center to different stimuli during sleep; 2) instability of the respiratory feedback regulation of the central nervous system to hypoxemia, especially due to changes in CO2 concentration; 3) abnormalities in the expiratory and inspiratory conversion mechanisms, etc.
Obstructive sleep apnea hypoventilation syndrome (OSAHS)
OSAHS accounts for the majority of SAHS, with family clustering and genetic factors. Most of them have pathological basis of narrowing of the upper airway, especially the nasal and pharyngeal areas, such as obesity, allergic rhinitis, nasal polyps, tonsillar hypertrophy, soft palate relaxation, excessive length and thickness of the palatal lobe, tongue hypertrophy, posterior tongue root, mandibular recession, temporomandibular joint dysfunction and small jaw deformity. Some endocrine diseases can also be combined with the disease. The pathogenesis may be related to the increased collapse of the soft tissues and muscles of the upper airway in the sleep state and the decreased responsiveness of the upper airway muscles to the stimulation of low oxygen and carbon dioxide during sleep, in addition to the combined effect of neurological, humoral and endocrine factors.
Clinical manifestations of collapse daytime clinical manifestations of collapse
1, drowsiness: the most common symptom, the lighter manifested as daytime work or study time sleepy, drowsy, serious meal, talk with people can fall asleep, and even serious consequences, such as dozing off while driving lead to traffic accidents.
2, dizziness and weakness: due to repeated apnea and hypoxemia at night, the sleep continuity is interrupted, the number of awakenings increases, and the quality of sleep decreases, often with mildly different dizziness, fatigue and weakness.
3. Mental behavior abnormalities: inattention, decreased ability to perform fine operations, decreased memory and judgment, inability to perform work when symptoms are severe, and dementia may be manifested in the elderly. The damage of nocturnal hypoxemia to the brain and the change of sleep structure, especially the reduction of deep sleep phase, are the main reasons.
4.Headache: It often appears in the early morning or at night, vague pain is common, not severe, can last 1-2 hours, sometimes need to take painkillers to relieve, related to elevated blood pressure, intracranial pressure and changes in cerebral blood flow.
5, personality changes: irritability, agitation, anxiety, etc., family and social life are affected to a certain extent, due to the gradual emotional distancing from family members and friends, depression may occur.
6, hypogonadism: about 10% of patients may have hypogonadism or even impotence.
Clinical manifestations of nocturnal folding
1.Snoring: It is the main symptom, the snoring is irregular and of different heights, often alternating snoring-airflow stopping-panting-snoring, generally the time of airflow interruption is 20-30 seconds, individually up to 2 minutes or more, at which time the patient may appear obvious cyanosis.
2.Apnea: 75% of the co-sleepers in the same room or bed found that the patient had apnea and often pushed the patient awake for fear that the breathing could not be restored. apnea mostly terminated with gasping, holding awake or loud snoring. patients with OSAHS had obvious thoraco-abdominal contradictory breathing.
3.Wake up with suffocation: sudden wake up with suffocation after apnea, often accompanied by turning over, involuntary movement of limbs or even convulsions, or suddenly doing up, feeling panic, chest tightness or discomfort in the precordial area.
4, hyperactivity: due to hypoxemia, patients turn over and rotate more frequently at night.
5, hyperhidrosis: sweating is more frequent, obvious in the neck and upper chest, related to hypercapnia caused by respiratory effort and apnea after airway obstruction.
6.Nocturia: Some patients complained of more frequent urination at night, and individual urine loss.
7, abnormal sleep behavior: manifested as fear, shrieking, murmuring, nocturnal wandering, hallucinations, etc.
The manifestation of systemic organ damage folding
1, hypertension: the incidence of hypertension in OSAHS patients is 45%, and the treatment of antihypertensive drugs is not effective.
2, coronary heart disease: manifested as various types of arrhythmias, nocturnal angina pectoris and myocardial infarction. It is caused by endothelial damage of coronary arteries due to hypoxia, lipid deposition in the intima, and increased blood viscosity due to erythrocyte increase.
3, Various types of arrhythmias.
4.Pulmonary heart disease and respiratory failure.
5, Ischemic or hemorrhagic cerebrovascular disease.
6, mental abnormalities: such as manic psychosis or depression.
7, diabetes mellitus.
Examination methods folded
1. Blood test: In prolonged illness and severe hypoxemia, blood red blood cell count and hemoglobin may be increased in different degrees.
2. Arterial blood gas analysis: Those with severe disease or combined pulmonary heart disease or respiratory failure may have hypoxemia, hypercarbia and respiratory acidosis.
3. Chest X-ray examination: In case of complicated pulmonary hypertension, hypertension and coronary artery disease, there may be corresponding symptoms such as enlarged heart shadow and prominent pulmonary artery segment.
4. Pulmonary function tests: In severe cases with pulmonary heart disease and respiratory failure, there are different degrees of ventilation dysfunction.
5. Electrocardiogram: In case of hypertension and coronary artery disease, changes such as ventricular hypertrophy, myocardial ischemia or cardiac arrhythmia may occur.
6. Upper airway MRI examination: to determine the site of upper airway obstruction and the degree of obstruction.
7. Sleep breathing monitoring.
Diagnostic method folding
1. Clinical diagnosis: The preliminary clinical diagnosis can be made based on the patient’s snoring during sleep with apnea, daytime drowsiness, body obesity, thick neck circumference and other clinical symptoms.
2.Polysomnography: PSG monitoring is the gold standard for confirming the diagnosis of SAHS and can determine the type and severity of the disease.
3.Etiological diagnosis: Ear, nose and throat and oral examination are routinely performed for confirmed SAHS to understand whether there are local anatomical and developmental abnormalities, hyperplasia and tumors. Head and neck radiographs, CT and MRI to determine the cross-sectional area of the oropharynx can be used to determine the localization of stenosis. Measurement of the endocrine system can be performed in some patients.
Prevention methods fold
1.Enhance physical exercise and maintain good living habits.
2.Avoid smoking and alcohol addiction, because smoking can cause aggravation of respiratory symptoms, and drinking alcohol aggravates snoring, nocturnal breathing disorder and hypoxemia. Especially drinking alcohol before bedtime.
3.For obese people, we should actively reduce weight and strengthen exercise. Our experience is to reduce the weight by more than 5-10%.
4.Snoring patients mostly have decreased blood oxygen content, so it is often accompanied by hypertension, heart rhythm disorder, increased blood viscosity and increased heart burden, which may easily lead to the occurrence of cardiovascular and cerebrovascular diseases, so we should pay attention to the monitoring of blood pressure and take antihypertensive substances on time.
5, bedtime sedative, sleeping matter is prohibited, so as not to aggravate the inhibition of the central regulation of respiration.
6, take the side sleep position, especially the right side of the sleep position is appropriate to avoid the tongue, soft palate, uvula relaxation back during sleep, aggravating the upper airway blockage. A small leather ball can be pasted on the back during sleep, which helps to keep the lateral sleep position compulsorily.
7.Surgical treatment, such as nasal surgery, palatopharyngoplasty, tongue root surgery, etc., is performed according to different conditions of patients.
8.Patients should eat soft food mainly after surgery, do not eat too hot food. Avoid strenuous activities. For postoperative patients with high quality of life requirements, optional ventilator can be used for better results.
9.For patients who do not want to have surgery, optional ventilator can also be applied.