neonatal laryngeal stridor
Introduction
Introduction to neonatal laryngeal wheezing The laryngealstridor of newborn indicates that the throat wheezing sound that occurs during birth or within a few weeks after birth is caused by airflow through the narrow airway segment during breathing, and the airway stenosis can be caused by a variety of causes. Occurs in the winter and spring season. It is most common in infants and young children, especially newborns and infants. In severe cases, it can cause difficulty breathing or even respiratory failure. basic knowledge The proportion of illness: 0.002% Susceptible people: children Mode of infection: non-infectious Complications: chicken breast respiratory infection
Cause
Causes of neonatal laryngeal wheezing
Trauma (45%)
Trauma induces the nerves that innervate the vocal cords, that is, the recurrent laryngeal nerve damage can cause the disease. If the recurrent laryngeal nerve is damaged, vocal cord paralysis will appear. Because the recurrent laryngeal nerve on the left side is longer and more distorted, it is vulnerable to injury at birth. In addition, cardiovascular, pulmonary or esophageal lesions can suppress the laryngeal nerve caused by laryngeal nerve.
Congenital factors (15%)
Congenital simple laryngeal wheezing (laryngeal tracheal cartilage softening), congenital laryngotracheal dysplasia (throat, epiglottis, epiglottis, subglottic stenosis, tracheal stenosis, etc.), congenital macrovascular abnormalities (double aortic arch ), congenital laryngeal cyst or tumor (laryngeal cyst, laryngeal hemangioma, laryngeal papilloma, intralaryngeal thyroid, etc.), congenital small mandibular deformity. Mainly because the throat tissue is too weak, the throat collapses inward when inhaling, and the wheezing that occurs when the mouth of the throat is blocked, it is also called throat softening.
Pathogenesis
The throat is caused by turbulence of the airflow through the narrow section of the airway during inhalation or exhalation.
1. Physiological and anatomical features: Newborns are prone to stenosis due to small airway diameter, while cartilage supporting the airway is poorly developed, making it prone to distortion and collapse. Therefore, neonatal airway is more likely to occur than other age groups. Physiological stenosis.
Anatomically, the airway can be divided into three parts:
1 upper door: including the nose, nasopharyngeal cavity, oropharynx and hypopharynx.
2 throat segment (soundslide segment): including vocal cords, subglottic area, neck tracheal section.
3 intrathoracic segment: including the trachea and bronchus in the chest.
2. Inspiratory laryngo: The upper part of the glottis is the weakest part of the newborn. Obstructive diseases in this area can often cause inspiratory laryngo, such as small jaw or giant tongue deformity, which can block the gas due to the tongue backwards. Road.
3. Biphasic laryngeal: The larynx is the most anatomically narrow part of the airway of the newborn. The diseases here are congenital throat softening, vocal cord paralysis, subglottic stenosis, throat, subglottic hemangioma and laryngeal cyst. It can cause laryngeal obstruction, and the airflow is also affected during inhalation and exhalation, so it is typical of biphasic throat.
4. Exhaled throat: congenital anomalies of the trachea and bronchi in the thoracic cavity are relatively rare, such as tracheal softening, tracheal stenosis, congenital large vessel abnormalities, oppression of the airway, or recurrent gastroesophageal reflux caused by the airway Inflammation can cause airway obstruction in this segment, and it is characterized by expiratory throat.
Prevention
Neonatal laryngeal wheezing prevention
It is believed that due to malnutrition during pregnancy, the lack of calcium in the fetus can often cause the laryngeal cartilage to soften. Therefore, it is necessary to pay attention to the health care work during pregnancy, strengthen nutrition during pregnancy, and prevent various infectious diseases. Usually pay attention to prevent cold and frightened, so as to avoid respiratory infections and throat, and increase throat obstruction. If the attack is heavier, it is difficult to inhale, and the position of the baby can be adjusted. The lateral position can relieve the symptoms, and occasionally the severe laryngeal obstruction requires tracheotomy.
Complication
Neonatal laryngeal warping complications Complications Chicken chest respiratory infection
Can be complicated by hypoxemia. In the case of secondary respiratory infections, the symptoms of dyspnea are significantly aggravated, while the secretions of the respiratory tract are not well discharged, and squeaking occurs. Long-term larynx can cause chicken breasts.
Symptom
Neonatal Laryngeal Wheezing Symptoms Common Symptoms Difficulty breathing, neonatal throat wheezing, swallowing difficulty, vocal cord paralysis, tremor
1. Congenital simple laryngeal wheezing : Congenital simple laryngeal wheezing refers to excessively weak laryngeal tissue, inward collapse when inhaling, and wheezing that blocks the upper mouth of the laryngeal cavity. The weakness of the laryngeal tissue may be during pregnancy. Malnutrition, caused by lack or imbalance of calcium or other electrolytes in the fetus, it is also known as laryngeal softening. It is the most common cause of laryngeal wheezing in neonates, accounting for 60% to 70% of neonatal larynx. It is a high-pitched chicken-like wheezing sound, and it can also be a low-pitched tremor sound. It usually occurs only when inhaling, and when a heavy person exhales, it can also sound. The symptoms are mostly intermittent, disappearing when sleeping or quiet. When crying and swaying, it is obvious when it is lying down. It is relieved or disappears when lying down. It is obvious when lying on the back. When the throat is heard, it can be accompanied by the sternal fossa, the intercostal space and the upper abdomen are depressed, but the growth and development are good, the crying is normal, and the throat is often at 18 It gradually disappeared on its own within 24 months, no special treatment was needed, and some severe cases may have difficulty breathing and cyanosis.
2. Vocal cord paralysis: vocal cord paralysis is also a common cause of neonatal laryngo, second only to laryngeal softening, unilateral vocal cord paralysis is more common, mostly on the left side, which is due to the longer and more distorted left recurrent laryngeal nerve. It is susceptible to traction and injury at birth, and can be accompanied by other ipsilateral peripheral nerve injuries, such as facial nerve palsy, brachial plexus and radial nerve palsy. If there is no obvious history of birth injury or peripheral nerve injury, unilateral Vocal cord paralysis, should pay attention to the exclusion of cardiovascular, pulmonary or esophageal lesions, because the left recurrent laryngeal nerve surrounds the distal end of the aortic arch artery catheter opening, prone to stretched large blood vessels, the right recurrent laryngeal nerve is located under the left subclavian artery Protected, so the right side of the right vocal cord paralysis is extremely rare, unilateral vocal cord paralysis throat is biphasic, often accompanied by hoarseness or aphonia, no cyanosis and feeding difficulties, more can relieve themselves without treatment, bilateral vocal cord paralysis Mostly central, due to prenatal or postnatal hypoxia damage brain stem, can be accompanied by dysphagia and other cranial nerve damage, often crying low, high-pitched dual-phase throat and Suction distress, sometimes after requiring intubation or tracheostomy, some patients can resume their own slow, so further surgical intervention should be delayed until 4 years.
3. Congenital larynx : abnormal tracheal dysplasia This group of diseases includes various anatomical abnormalities that produce larynx and tracheal stenosis. Congenital throats have throat squeak when they are born, hoarseness or weakness, and those with large sputum may have difficulty breathing. Need to be diagnosed and treated early, congenital subglottic elastic cone tissue hypertrophy or annular cartilage malformation, can cause subglottic stenosis, obstruction, severe throat when the birth, but the pronunciation and crying is normal, congenital tracheal stenosis can be trachea The lesion itself (incomplete tracheal cartilage ring, tracheal ring softening, tracheal fistula, tracheal cyst, etc.) or extratracheal lesions (neck tumor, mediastinal tumor or vascular abnormalities, etc.) caused by compression, more children than at birth or shortly after birth That is, there is persistent laryngeal sound, which is more obvious when exhaling, cries and pronunciation are normal, and severe cases may have difficulty breathing.
4. Congenital macrovascular abnormalities : large vessel abnormalities are caused by improper position of the aortic arch or one or more large vessels of the aortic artery. When these abnormal blood vessels form a tight vascular ring, the trachea or esophagus can be compressed. The vascular ring formed by the double aortic arch is the tightest. Most of the phlegm is formed at the time of birth or shortly after birth. The exhalation is more obvious. In severe cases, it is difficult to breathe and cyanosis. It is rare to swallow, but eat. The throat can be aggravated, because the vascular ring formed by the double aortic arch can not increase with the growth of the child, so the compression symptoms become heavier as the child grows up, and need to perform surgical orthopedics as early as possible, others are lost. The large blood vessels (such as the right aortic arch, labyrinth of the subclavian artery, innominate artery, pulmonary artery, etc.) and the vascular ring formed by the arterial ligament or arterial catheter are mostly open and can increase with the growth of the child, so it is very Less symptoms appear in the neonatal period.
5. Congenital laryngeal cysts or tumors: congenital laryngeal cysts, thyroid or laryngeal tumors in the larynx (hemangioma, papilloma) can cause neonatal laryngeal wheezing, manifested as dumb or aphasia, bipolar wheezing, The degree of difficulty in breathing depends on the size of the tumor.
Nearby tissues such as cervical water cysts, thyroid tongue cysts, congenital giant tongue or vagus thyroid and congenital goiter at the base of the tongue can cause respiratory distress, but rarely cause wheezing.
6. Others : The excitability and incoordination of the nervous muscles of the larynx may also be a factor in the production of laryngeal sound. Due to the high excitability of the neonatal vagus nerve, mild stimulation of the respiratory tract and gastrointestinal tract can become a pathological impulse, via the vagus nerve. Afferent fibers act on the vocal center of the fourth ventricle and cause laryngeal. Cholinergic blockers ( scopolamine, atropine) are effective drugs for blocking nerve throat, and children with long-term tracheal intubation mechanical ventilation Due to local edema caused by vocal cord or ring cartilage injury or secondary subglottic stenosis, laryngeal often occurs after extubation, the incidence is about 10% of children with intubation, using soft tracheal tube, skilled intubation technique, good The fixation and application of dexamethasone before extubation can reduce the occurrence of this complication.
Examine
Newborn throat wheezing
The throat caused by infantile hand, foot and ankle can have low blood calcium; in addition, the peripheral blood leukocytes and neutrophils increase when infected.
1. Direct laryngoscopy: is the most important diagnostic method. Congenital simple laryngeal wheezing direct laryngoscopy shows that the laryngeal tissue is soft and slack. When inhaling, the laryngeal tissue curls into the larynx, and when exhaled, it is blown out. When the direct laryngoscope will be provoked or stretched into the vestibule of the larynx, the throat sounds disappear, and the diagnosis, laryngeal cyst, tumor, epiglottis and vocal cord paralysis can only be confirmed by laryngoscopy.
2. Bronchoscopy: The subglottic and tracheal lesions must be examined by bronchoscopy to confirm the diagnosis, if necessary, by bronchoscopy.
3. X-ray examination: X-ray film and esophageal swallowing examination of the neck and chest are helpful for diagnosing the cause of neonatal throat.
4. Ultrasound examination: If necessary, cardiac ultrasound examination can help diagnose the cause of neonatal throat.
Diagnosis
Diagnosis and diagnosis of neonatal laryngeal wheezing
diagnosis
According to the history and symptoms, it is not difficult to make a diagnosis of neonatal laryngeal wheezing. In addition to the history and clinical features, direct laryngoscopy or fiberoptic laryngoscopy should be used to determine the nature of laryngeal malformation. Direct laryngoscopy often Can identify congenital simple laryngeal wheezing, laryngeal cyst, tumor, throat, epiglottis, epiglottis and vocal cord paralysis, etc., but subglottic and tracheal lesions must be diagnosed by bronchoscopy, if necessary X-ray film and esophageal swallowing examination, etc., to determine the cause of neonatal laryngeal diagnosis as soon as possible.
Differential diagnosis
Through medical history, whether there is a birth injury, whether there is improper operation, damage to the recurrent laryngeal nerve, history of mechanical ventilation with or without tracheal intubation, and nutritional status of the mother during pregnancy, with or without hypocalcemia, plus direct laryngoscopy and imaging examination It allows us to identify whether it is congenital or acquired throat, and to identify various etiological diagnoses.
In order to rule out the throat seen in infantile hand, foot and ankle, it is sometimes necessary to determine serum calcium. In addition, it should be differentiated from the following diseases:
1. Other diseases of the throat: Congenital laryngeal cysts can occur in the upper glottic area or near the epiglottis. In the neonatal period, it shows laryngeal wheezing and inspiratory dyspnea. When lying sideways or head back, the symptoms may be different. The degree of relief, generally silent, can be diagnosed by direct laryngoscopy or fiberoptic laryngoscopy, and surgery should be performed as soon as possible.
2. Tracheal abnormalities: congenital tracheal fistula, tracheal stenosis, etc. can cause wheezing, tracheal cartilage ring is weak, deformed, island-like residual or absent, horseshoe-shaped tracheal ring flattening, can make the tracheal wall weak, can not resist the trachea The pressure outside the cavity, or because the membrane part of the tracheal wall is close to the anterior wall of the trachea, so that the trachea can be collapsed, and throat wheezing can occur.
In addition, it may be secondary to long-term compression of the trachea or bronchus, causing laryngeal or dyspnea, such as neck tumors, enlarged lymph nodes and thymus hypertrophy, which can compress the trachea and bronchi to cause secondary softening and cause laryngeal And dyspnea, chest X-ray, tracheal lipiodol angiography, fiberoptic bronchoscopy chest spiral CT and other examinations can help diagnose.
3. Small jaw: It is characterized by small jaw, short or relatively thick tongue, inhalation with snoring sound, and obvious inspiratory difficulty. When inhaling, the patient's lower jaw is backward, and the mouth is tightly closed. The tongue roots fall backwards, the soft palate is lifted up, the nasopharyngeal cavity is blocked, causing severe breathing difficulties, and the scabbard is most obvious. Therefore, the congenital funnel chest is sometimes mistakenly considered clinically, such as taking the child to the side or prone position. With the hand held up the lower jaw, the difficulty of breathing is relieved immediately. The sick child often cannot breastfeed due to difficulty in breathing, resulting in malnutrition and respiratory infection. Usually only the child is placed in the lateral position, sometimes the lower jaw is lifted with a simple jaw bracket. You can also put a silicone tube along the corner to improve ventilation.
