Pediatric obesity dysventilation syndrome
Introduction
Introduction to pediatric obesity dyspnea syndrome Obesity-pulmonary hypoventilation syndrome (obesity-pulmonary hypoventinationsyndrome), also known as obesity cardiopulmonary insufficiency syndrome (pickwickiansyndrome), obesity with cardiopulmonary failure, idiopathic alveolar hypoventilation syndrome, Cardiopulmonary-obesity syndrome, obesity-dyspnea-sleepiness syndrome, narcolepsy associated with diabetic hyperinsulin syndrome, etc. This symptom is common in children with extremely obese body and is a clinical syndrome of severe obesity. It is related to obesity to hypoventilation and is a type of pulmonary alveolar hypotension syndrome. It is a special type of pulmonary heart disease and is a common and serious complication in obesity patients. This symptom refers to a series of symptoms caused by poor alveolar ventilation in patients with extreme obesity without primary heart or lung disease. If the weight is reduced, the clinical symptoms can be significantly improved. basic knowledge The proportion of sickness: 0.01% Susceptible people: children Mode of infection: non-infectious Complications: arrhythmia fatty liver amenorrhea sleep apnea syndrome sudden death pulmonary embolism
Cause
Pediatric obesity dyspnea syndrome
Abdominal fat accumulation (30%):
Abdominal fat accumulation, increased intra-abdominal pressure, increased diaphragm pressure, increased chest pressure, massive fat accumulation in the mediastinum, thick chest wall, limited thoracic expansion and diaphragmatic movement, limiting lung respiratory function, lower chest compliance, causing Poor lung ventilation, decreased tidal volume, decreased lung ventilation, decreased lung function, decreased patient vital capacity, reserve expiratory volume, functional residual capacity, and total volume, and increased body weight, and uneven ventilation Large, so that when the arterial blood carbon dioxide partial pressure is increased, the oxygen partial pressure is decreased.
Severe obesity (30%):
People with severe obesity also have excess fat around the neck, hypertrophy of the tongue, and falling of the tongue root, which can lead to different degrees of upper airway obstruction. In addition, the reduction of ventilation is limited, and the ventilation is limited. The result is carbon dioxide retention and hypoxemia. Symptoms, manifested as difficulty breathing, can not be supine, intermittent breathing during sleep, cyanosis, excessive carbon dioxide accumulation in the blood, causing respiratory acidosis, can appear unconsciousness and lethargy, causing periodic tracheal occlusion during sleep, Insomnia or deprivation of sleep syndrome, sleep apnea (airway obstruction or central) syndrome, the interval between each breath after asleep is prolonged, long-term arterial blood carbon dioxide partial pressure increases, making the central nervous system high The reaction of carbonic acid is low, the respiratory center induced by the increase of carbon dioxide in the blood is excited, and it is in a state of loss of function. It is not sensitive to hypoxic respiratory reaction and has periodic breathing, which disturbs the rest of the patient, causing diurnal sleepiness, lack of energy, etc. .
In a state of hypoxia for a long time (30%):
Further, due to prolonged hypoxia, patients are prone to secondary polycythemia, increased blood viscosity, increased circulation resistance, early use of heart reserve during activities, and insufficient cardiac function. Patients with severe obesity are often accompanied by Increased total left ventricular load and venous return, increased venous pressure, increased pulmonary hypertension and right heart load, edema, jugular vein engorgement and even cardiac insufficiency, decreased ventilatory function, decreased aerobic capacity Such as causing shortness of breath, difficulty breathing, hypoxia, cyanosis, end-stage obesity cardiopulmonary insufficiency syndrome, prone to right ventricular hypertrophy, enlarged heart or congestive heart failure.
Energy intake for a long time exceeds consumption, resulting in excessive accumulation of body fat, to weight significantly exceeds the same age, the standard of normal height and normal children, obese people need more oxygen because of weight gain, but the lungs of obese people can not only increase Function, but the lung capacity is significantly lower than normal children, the main cause of cardiopulmonary insufficiency syndrome and the increase of adipose tissue in the chest, abdomen and whole body of the patient, leading to a reduction in the volume of the thoracic cavity, limited movement of the diaphragm, lungs in the patient, ventilation function Limited, heart function, nervous system damage and other changes.
Prevention
Pediatric obesity ventilatory syndrome prevention
Mainly to develop good eating habits, not partial eclipse, high fat, high calorie food. Develop the habit of participating in various physical activities and labor. For example, if you can walk, try not to take the car. When you go up and down the building, you must climb the building yourself instead of taking the elevator for a healthy search. Develop a habit of exercising every day.
Complication
Pediatric obesity dyspnea syndrome complications Complications arrhythmia fatty liver amenorrhea sleep apnea syndrome sudden death pulmonary embolism
Cardiovascular system
Heart failure due to long-term heart overload, although right heart failure is common, but should also pay attention to left heart failure (sometimes can be the main performance), and common arrhythmia.
2. Digestive system
Gastrointestinal hemorrhage can occur when gastritis or ulcer is complicated. The cause is stress response, gastric dilatation, excessive gastric acidity and application of hormones. Pay close attention to hematocrit, hemoglobin changes and presence or absence of fecal occult blood, 50% Patients may have varying degrees of fatty liver, cholelithiasis, and the like.
3. Hormone metabolism disorder
In severely obese women, males can increase to twice the normal value, and estrogen is also significantly increased, which can lead to early menarche in adolescent girls, abnormal ovarian function in adult women, amenorrhea infertility or rare menstruation, and can stimulate the mammary gland And abnormal uterine hyperplasia.
4. Infection
Pulmonary infection is a common complication due to secondary immune dysfunction, impaired lung clearance, catheter placement, respiratory therapy and other device contamination, often to respiratory infections, and acute respiratory failure after respiratory infections It is also prone to dermatitis, bloated skin, urinary and digestive system infections.
5. Other
Respiratory distress, sleep apnea can be sudden death, renal failure and acid-base balance disorders can occur, due to long-term bed rest and dehydration induced deep vein thrombosis and pulmonary embolism.
Symptom
Pediatric obesity dyspnea syndrome symptoms common symptoms dyspnea beer belly snoring snoring respiratory failure severe obesity baby overweight fatigue tidal breathing shortness
The main clinical manifestations of the patient are: no supine, palpitations, cyanotic lips, systemic edema, symptoms of dyspnea, and with the development of the disease, the patient has intermittent or tidal breathing, unconsciousness, lethargy or lethargy.
1. Symptoms and signs of hypoventilation A series of symptoms of respiratory failure, such as bruising and respiratory distress, blood gas examination see hypoxemia and carbon dioxide retention.
2. Respiratory symptoms and signs of breathing are shallow, often have apnea episodes at night, with peripheral or mixed sleep apnea, accompanied by upper airway obstruction and nighttime sleep snoring.
3. Cardiac symptoms and signs Early symptoms include cough, shortness of breath, palpitations, lower extremity edema and other symptoms. Long-term dyspnea may lead to chronic pulmonary heart disease and heart failure. When right heart failure is aggravated, dyspnea may occur, cyanosis. A small number of patients have a generalized heart failure.
4. Neurological symptoms and signs of hypoxia, fatigue, headache, dizziness, palpitations, excessive sweating, irritability, paralysis, convulsions, carbon dioxide retention, can cause hallucinations, mental disorders, daytime sleepiness, a small number of children with mental retardation or dullness.
Such patients do not respond well to the effects of general cardiotonic and diuretic treatments, giving intermittent oxygen or selective application of central respiratory excitement.
Examine
Examination of pediatric obesity dyspnea syndrome
1. Blood gas changes PaO2 , PaCO2 .
2. Metabolic disorders are mainly characterized by abnormal insulin receptors, decreased glucose transport and metabolic capacity, and often hyperinsulinemia, insulin antagonism, impaired glucose tolerance, increased blood glucose, and increased blood lipids.
3. Blood seems to increase peripheral blood erythrocytes.
4. X-ray examination chest radiograph can be seen on both sides of the squat, the pulmonary artery segment is protruding, the right heart is hypertrophy.
5. Pulmonary function tests mainly showed restrictive ventilatory disorders, lung volume, vital capacity, tidal volume decreased, functional residual capacity decreased, and lung capacity was significantly lower than normal children.
6. Electrocardiogram myocardial ischemia and hypoxia damage.
Diagnosis
Diagnosis and differential diagnosis of obesity and ventilatory syndrome in children
diagnosis
Weight exceeds the same sex, the average height of normal children is 20% for obesity, body weight is more than 30% to 39% for moderate obesity, more than 40% to 59% for severe obesity, more than 60% for extreme obesity, according to obese With reduced ventilation, clinical manifestations of the heart and nervous system symptoms and signs, combined with pulmonary function tests and blood gas analysis can be diagnosed.
Differential diagnosis
1. Inhibition of the respiratory center and drugs, encephalitis and other lesions inhibit the respiratory center, reduce respiratory motility, to ventilatory dysfunction, resulting in the identification of hypoxia and carbon dioxide retention.
2. Pulmonary lesions
(1) Physiological ineffective cavity to increase ventilation: in pneumonia, bronchiolitis, asthma and pulmonary edema, rapid breathing, airway spasm, stenosis or obstruction, reduced ventilation, increased physiological ineffective cavity, decreased respiratory efficiency, breathing Muscle paralysis, such as infectious polyradiculitis, pleural effusion, thoracic and lung expansion is limited, alveolar can not normally expand, tidal volume decreased resulting in decreased ventilation, resulting in increased PaCO2, PaO2 decreased.
(2) Ventilation/blood flow ratio (V/Q) imbalance: normal V/Q average is 0.8, V/Q ratio increases with ineffective cavity-like ventilation, ie alveolar ventilation but insufficient blood flow, seen when local blood perfusion is reduced The ratio of the ineffective cavity volume (VD) to the tidal volume (VT) (VD/VT) can be expressed as normal, 0.3, pulmonary embolism, acute lung injury, and ARDS, VD/VT is significantly increased, and ARDS can be increased to 0.75, V/ Q decline is pathological pulmonary arteriovenous shunt, refers to blood flow through non-ventilated or poorly ventilated alveoli, which is the cause of severe hypoxemia, mainly manifested as a significant decrease in PaO2, increasing oxygen concentration can not increase arterial oxygen partial pressure More common in local ventilation abnormalities, such as pneumonia, atelectasis, pulmonary edema, etc., with shunt scores, normal only 5%, greater than 15% will seriously affect oxygenation.
(3) Dispersion disorder: There is an abnormality in the diffusion of oxygen through the alveolar capillary membrane. Any diffuse area reduction (such as pneumonia, atelectasis) or diffuse membrane thickening (such as pulmonary edema, pulmonary fibrosis) leads to diffusion disorder. Since the dispersing ability of carbon dioxide is about 20 times larger than that of oxygen, the dispersing disorder mainly refers to oxygen, which is characterized by a decrease in PaO2, but no carbon dioxide retention. Usually, the ventilation disorder is judged by the differential pressure of pulmonary alveolar arteriovenous oxygen. PaO2 is more sensitive, it can react with oxygen earlier, and the normal value of alveolar oxygen partial pressure [(Aa)DO2] is 0.67-2.0 kPa (5-15 mmHg). This difference is mainly due to some short circuit in normal anatomy. And V/Q values in different parts of the lung are inconsistent, (Aa) elevated DO2 suggests ventilation disorder, and some people put forward >6.7kPa (50mmHg) as one of the diagnostic criteria for acute respiratory failure, but attention should be paid to the reduction of cardiac output and This value can also be increased when oxygen is absorbed.
The consequences of insufficient ventilation function have the following three characteristics: PaO2 must decrease; PaCO2 generally does not increase; increasing oxygen absorption can not improve PaO2.
In short, the most common cause of PaO2 decline in acute respiratory failure is V/Q imbalance. The most serious cause is the increase of pulmonary arteriovenous shunt. The most fundamental cause of PaCO2 increase is insufficient alveolar ventilation. In children with respiratory diseases, There may be ventilation disorders caused by different reasons. ARDS increases the intrapulmonary shunt; V/Q imbalance is a common condition in general lung lesions.
3. Simple suppression of secondary obesity combined with medical history, physical signs and laboratory data, etc., first identified as a simple secondary depression, such as high blood pressure, centripetal obesity, purple lines, amenorrhea, etc. with 24h urine 17 - those with high hydroxysteroids should be considered for hypercortisolism. It should be administered in small dose (2mg) dexamethasone inhibition test to identify the thyroid function test such as T3, T4 and TSH. To determine whether there is hypothyroidism, anterior pituitary dysfunction or hypothalamic syndrome should be performed pituitary and target gland endocrine test, check the saddle, visual field, vision, etc., if necessary, for head CT examination, etc. Sphenoid enlargement should consider pituitary tumors and exclude empty sella syndrome, amenorrhea, masculinization should be excluded except polycystic ovary, no obvious endocrine disorders, afternoon foot swelling, morning relief should be excluded from water, sodium retention obesity Symptoms, vertical position water test is very helpful, in addition, it is often necessary to pay attention to whether there are diabetes, coronary heart disease, atherosclerosis, gout, cholelithiasis and other concomitant diseases, as for other types of rare obesity, can be combined Its clinical characteristics are analyzed and judged.
