sudden infant death syndrome
Introduction
Introduction to sudden infant death syndrome Sudden Infant Death Syndrome (SIDS), also known as cotdeath (cribdeath), refers to a sudden and unexpected death of a baby who appears to be completely healthy. The second international SIDS meeting in Seattle, North America, in 1969, defined it as: Infant Sudden accidental death, although after the death, although the autopsy failed to determine the cause of death, said SIDS. Sudden Infant Death Syndrome is the most common cause of death between 2 weeks and 1 year of age, accounting for 30% of mortality in this age group. The incidence rate is generally 12, and its distribution is worldwide. Generally, there are many cases in the middle of the night to early morning. Almost all deaths of sudden infant death syndrome occur in infants' sleep. basic knowledge The proportion of sickness: 0.01% Susceptible people: children Mode of infection: non-infectious Complications: sudden death
Cause
Causes of sudden infant death syndrome
High risk factors associated with mothers and babies (15%):
High-risk factors associated with mothers include younger pregnant women, less education, smoking during pregnancy, abnormal placenta, late prenatal care or lack of perinatal care, and high-risk factors associated with infants, including prone or lateral sleep, and Others (often mothers) sleep in bed, bedding is too soft, premature or low birth weight, less than gestational age, passive smoking, overheating, males, etc. Among them, lateral sleep may be premature and/or low birth weight One of the high risk factors for SIDS is multiple risk factors for SIDS. The relative risk of SIDS in twins is twice that of singleton. As the birth weight decreases, the risk of SIDS increases in both single and twin fetuses.
Ethnic differences (5%):
The incidence of SIDS in non-whites, such as blacks and American Indian/Alaskans, is two to three times higher than that of the Spaniards and Asians, indicating that SIDS has a certain ethnic susceptibility.
Family socioeconomic status (10%):
Poor family socioeconomic background can increase the incidence of SIDS.
Hypoxia and hypercapnia (15%):
Autopsy confirmed structural and functional changes in the lungs, brainstem or other organs in SIDS cases. Nearly two-thirds of cases had histological or biochemical evidence of chronic hypoxia or mild asphyxia before sudden death. Some studies found that nearly 60% The level of vascular endothelial growth factor (VEGF) in the cerebrospinal fluid of SD IS cases is significantly increased. Since hypoxia is an important cause of the increase of VEGF, it is believed that an anoxic event occurs several hours before the onset of SIDS, since the beginning of hypoxia VEGF gene transcription and VEGF protein expression can take at least several hours (the level of VEGF in the tissue can be measured 6 h after hypoxia, peak at 12 h, and return to basal level at 24 h). The most common cause of these hypoxic events may be Bradycardia, upper airway obstruction or periodic breathing, hypoventilation caused by multiple causes and hypoxia eventually induce SIDS, prenatal exposure to nicotine in pregnant women, in the case of hypoxia/hypercapnia in infants, can aggravate infants Bradycardia causes SIDS to occur.
Infection (18%):
Numerous studies have shown that some SIDS cases may be slightly infected before sudden death and are not noticeable. 1 Virus infection: SIDS has a peak incidence in winter, which may be related to mild virus infection in winter. It is difficult to find it at the autopsy. Bacterial infection: 5. 1% of cases of SIDS have a history of upper respiratory tract infection caused by B. pertussis, so B. pertussis may be one of the causes of SIDS. B Lackwell and other believe that potential harmful bacteria colonization and inflammatory reaction make the immune-infected baby It is more susceptible to damage, the up-regulation of pro-inflammatory cytokines caused by bacterial toxins and causing severe inflammatory reactions is an important cause of SIDS. 3 Pneumocystis infection: Chabé et al. found Pneumocystis in paraffin-embedded sections of lung tissue from SIDS cases. Therefore, it is believed that Pneumocystis infection may also be one of the causes of SIDS.
Pathogenesis
1. Pathogenesis The pathogenesis of SIDS has not been clarified. It is currently considered to be the result of interaction of various factors. Brainstem dysplasia or maturity delay associated with cardiac respiratory function control, sleep arousal regulation and circadian rhythm regulation is considered to be the most Persuasive and most reasonable hypothesis, which is consistent with the brainstem dysplasia seen in autopsy, which suggests that brainstem heart respiratory center development disorders can directly affect its function and affect the arousal response, the physiology of such infants during sleep. Insufficient stability, can not wake up in time to avoid some fatal noxious stimuli, wake-up reaction defects are necessary for the occurrence of SIDS, but in the absence of other biological or epidemiological risk factors, it is not enough to cause SIDS, prone Sleep increases airway obstruction and the possibility of repeated inhalation, leading to hypercapnia and hypoxemia, which may develop into fatal asphyxia, especially on very soft bed surfaces that increase airway obstruction and repeated inhalation. Possibilities, leading to hypercapnia and hypoxemia, may develop into fatal asphyxia, especially on very soft bed surfaces Increase the risk of sleep prone position, also it suggested that prone sleeping position can cause significant heat stress, the heart defects in babies have breathing control further damage.
A et al. classify the cause of sudden infant death as the following viral infections, hypoxia, exogenous antigens, neuroreflex disorder, etc. The more commonly recognized cause of death is central asphyxia. The autopsy data suggest that the adrenal gland has a small weight and a considerable surface. Large wrinkles, due to low adrenal gland secretion activity, long-term glucocorticoid deficiency, leading to metabolic disorders in various organs, especially brain metabolism disorders, may be the cause of sudden death in children, some children may be due to ventricular fibrillation or sympathetic excitability Sudden rise caused by imbalance of cardiac nerves, QT interval prolongation is a disorder of myocardial repolarization process, which can cause ectopic excitability and thus increase the possibility of lethal ventricular fibrillation, familial from prolonged QT interval It is suggested that the disease is autosomal dominant, and the virus infection plays an inducing role in the abnormal and uncoordinated reaction mechanism of sudden death in children. In the sudden death of children, the large thymus with adrenal insufficiency can reach 40%, so the thymus lymphoid and There is a relationship between sudden infant death and excessive thymic hyperplasia should be evidence of immune disorders.
In addition, pathological pregnancy history, botulism, long-term idiopathic apnea, gastric-esophageal reflux, apnea-hypopnea caused by laryngeal and upper airway chemoreceptors, invaded by more than normal amounts of antigen, vagus nerve Abnormalities, changes in pulmonary surfactant, and lack of medium chain acyl-CoA dehydrogenase (MCAD) may be one of the causes of certain SIDS.
2. The lack of specificity in the autopsy of children with SIDS seen in the autopsy, there is no necessary sign for the diagnosis of SIDS, but there are some common findings, such as 90% of children with a bit of bleeding, and other than the cause of the baby Death is obvious, and pulmonary edema is also common.
A study of SIDS autopsy revealed that 2/3 of children had histological evidence of chronic hypoxia, including adrenal brown fat residue, liver erythropoiesis, brainstem gliosis, and other structural abnormalities, except for astrocytes. In addition to hyperplasia, there are also tree-like spines and myelin formation. The primary site of the brainstem spines is located in the large nuclei of the reticular structure and the dorsal nucleus and orphan nucleus of the vagus nerve. Some patients with SIDS have reactivity in the medulla oblongata. Astrocytes increase, this increased site is not limited to the site related to respiratory regulation, substance P, a neuropeptide conduction medium found in selective sensory neurons of the central nervous system, in the pons of children with SIDS Increased, a small number of SIDS children with dysplasia of the arcuate nucleus, this site is where the ventral ventral heart respiratory center is located, and is closely related to the regulation of arousal, autonomic rhythm and chemoreceptor function, recently found in children with SIDS bow Abnormal receptors in the nucleus, including receptors that bind to kainic acid, muscarinic cholinergic receptors and serotoninergic receptors, and kainic acid receptors Integral with the muscarinic cholinergic receptor density decreases interrelated, the arcuate nucleus at least one or more neural lack neurotransmitter receptor, which comprises a lack of self-regulation, including arousal response, especially the heart-related respiratory control.
Other autopsy results were consistent with the body's response to mild chronic asphyxia. SIDS had pre- and post-natal growth retardation and increased cortisol concentrations in the blood. SIDS infants had higher levels of hypoxanthine in vitreous humor, due to the precursor substance of hypoxanthine. Adenosine (xanthine) is a respiratory system inhibitor that indicates tissue hypoxia for a prolonged period of time. These observations suggest a potentially important relationship between asphyxia and hypopnea, namely asphyxia due to various causes. It causes the decomposition of secondary adenosine monophosphate in the body to accelerate, resulting in adenosine accumulation which can cause persistent hyperventilation and form a vicious circle.
Prevention
Sudden infant death syndrome prevention
1. Back to sleep
Since the Sit-sleeping exercise, the incidence of SIDS has decreased significantly. If reported [27] decreased by 6.6% in the neonatal period (0-28 d), infants in January-June decreased by 9. 0%. The infants from July to November decreased by 6.1%, and in the cold season, the average season decreased by 11.2%.
2. Avoid infant prone and lateral position
Sleep prone and lateral position are the positions in which infants are prone to SIDS and should be avoided.
3. Use a hard bed surface
Avoid placing soft bedding on the crib, such as pillows, quilts, wool scarves, sheepskin blankets, stuffing toys, etc., in case the baby's face is wrapped or covered by them. It is recommended to cover the baby's hard mattress with a layer of sheets. As a baby's sleep.
4. Avoid smoking during pregnancy and passive smoking in infants. Smoking during pregnancy and smoking in the environment where the baby lives is an independent risk factor for SIDS and should be avoided.
5. It is recommended that the baby and the mother are in the same room, but the same bed with the mother within 20 weeks after the birth of the bed is an important risk factor for SIDS, but has little effect on the baby after 20 weeks [28].
6. Use a soothing teat
The use of a soothing teat can reduce the incidence of SIDS, especially during long sleep periods. If the baby refuses or the baby is asleep, it is not necessary. The mechanism by which the teat reduces the incidence of SIDS may be related to lowering the threshold of arousal. The side effect of using a soothing teat is The incidence of malocclusion is increased, but it can be restored after discontinuation; long-term use of infants with otitis media, intestinal infections and oral candida colonization increased.
7. Avoid overheating the baby
Infants should sleep in a cool environment, should not wear, cover too much, it is not appropriate to feel overheated when touching the baby.
8. Family monitoring device is not recommended
There is no evidence that cardiopulmonary monitors used in the home can reduce the incidence of SIDS, but it is important to strengthen home surveillance for infants with significant life-threatening events [31], including apnea (central or Occasional obstruction), skin color changes (usually referred to as cyanosis, pale, occasional erythema or multiple blood), obvious changes in muscle tone (especially decreased), sudden breathing and vomiting, etc. Helps to quickly understand apnea, airway obstruction, respiratory failure, assisted oxygen supply interruption and respiratory support failure.
9. Try not to use secondary careg ivers
About 20% of SIDS in the United States occur in non-parental care babies, often adorned by older children, child caregivers, relatives (such as grandparents, adoptive parents) or temporary nannies.
Parents who have lost their children due to sudden infant death syndrome are greatly traumatized and have no mental preparation for the tragedy; they often have too much guilt because they cannot find a clear cause for their death, and because of the police, social workers Or other personnel's investigations are aggravated, family members need help not only within a few days after the baby's death, but also need help at least in the next few months to alleviate their grief and guilt. At any time, this kind of help includes Conduct home visits immediately, discuss with parents and alleviate their panic, prevent them and other children from rushing into the hospital, endangering the safety of themselves and others; observing the environment in which sudden infant death syndrome occurs, and explaining the reasons for infant death .
The autopsy should be done as soon as possible. Once the results of the autopsy are known (usually within 8~12 hours), the deceased's relatives should be notified.
Complication
Complications of sudden infant death syndrome Complications
The ultimate consequence of sudden infant death syndrome is death with no other complications.
Symptom
Sudden Infant Death Syndrome Common Symptoms Bradycardia Proteinuria Dead Meningitis
1. The child has the following characteristics during his lifetime.
1 poor response to the environment;
2 easy to stop breathing or fail during feeding;
3 There is an abnormal crying. Some people noticed that there is a kind of high-pitched crying or short-powered sputum in SIDS. The tone often changes suddenly. There are different tones in the same crying. These manifestations are abnormalities in the pronunciation pipe above the throat and throat. Abnormal brainstem function, of course, the quiet and gentle personality does not all suggest SIDS, because the actual incidence of SIDS is only 2, so these rough and not specific performance, it is difficult to use as a potential disease screening Standard.
2. Screening criteria for high-risk children
Naeye has proposed eight maternal characteristics and 19 neonatal characteristics as criteria for screening high-risk children.
(1) Pregnant mothers: There are mainly:
1 The mother's hemoglobin 10g / dl at any time.
2 smoking.
3 infections.
4 proteinuria during pregnancy.
(2) Infant aspects: Features include:
1 The head is obviously deformed during childbirth.
2 need oxygen treatment.
3 unusual hug reflections.
4Apgar score 6 and so on.
Several scholars have used this standard to analyze large infants and a group of children who died of SIDS or high risk. Disappointing is the high rate of false positives (more than 90%). At this stage, there is no reliable screen with high specificity. Check the method to identify it early.
3. Clinically, the disease can be divided into 3 categories.
(1) Infectious diseases: Infectious diseases that have not been diagnosed in time (confirmed from autopsy), mainly acute respiratory infections.
(2) Sudden death: Sudden death after the acute phase of the disease or during the recovery period (confirmed from autopsy).
(3) Complete health: Children who appear to be completely healthy on the surface suddenly die.
There are no symptoms before the death, mainly in the sleep center, respiratory arrest, there is no accurate expected diagnosis method, the diagnosis of SIDS is limited to less than 1 year old, death background investigation and direct inquiry is found to be necessary for the death of the child, An autopsy should be performed in children suspected of having SIDS because SIDS is actually a diagnostic diagnosis. In the case of sudden unexplained infant death, some congenital and acquired diseases such as congenital heart disease that are not clinically diagnosed. Intracranial hemorrhage, myocarditis, meningitis and trauma can only be identified through autopsy. The significance of pathological examination is to explore the causes of sudden death to establish preventive measures.
One of the main goals of the SIDS study is to establish accurate screening methods to identify high-risk infants who may die from SIDS, expected respiratory and polysomnography screening methods, and to focus on monitoring abnormal forms of respiratory or rhythmic breathing, often lacking sufficient Sensitivity and specificity, not suitable for the expected recognition of children with SIDS, the risk of SIDS in infants, premature infants, siblings of children with SIDS who have experienced apparent life threatening event (ALTE) Significantly increased, this is currently the most useful method for identifying high-risk children with SIDS. ALTE refers to severe symptoms such as apnea, complexion change, low muscle tone and bradycardia. SIDS occurs in infants who require cardiopulmonary resuscitation due to ALTE. The rate of SIDS can reach 8% to 10%. The incidence of SIDS in infants with 2 ALTE is as high as 28%. The incidence of SIDS in premature infants is inversely proportional to the birth weight. The incidence of SIDS in SISD children is 3~. 5 times, up to 5/1000 ~ 8/1000 live births.
Examine
Examination of sudden infant death syndrome
Children with sudden infant death syndrome are difficult to diagnose before birth. When distinguishing from other diseases, if possible, the following related tests should be mainly performed: blood electrolyte concentration, blood sugar, arterial blood gas analysis, liver function, chest X-ray examination, electrocardiogram, Cardiac B ultrasound, EEG and head CT examination.
Diagnosis
Diagnosis and diagnosis of sudden infant death syndrome
It is difficult for children with sudden infant death syndrome to be diagnosed with other diseases before birth. It is generally necessary to determine the diagnosis by pathological anatomy. The significance of pathological examination is to explore the causes of sudden sudden death to establish preventive measures.
Diagnosing SIDS must be based on an environment that adequately investigates the occurrence of death, physical examination of the case, imaging and radiology, endoscopy and photography, and histology, microbiology, toxicology, biochemistry, metabolic diseases On the basis of screening and genetic testing, it has been suggested to use "suddenunexp lained infant death" instead of SIDS, but it has not been accepted, but it can be used for those who do not meet the SIDS Type I or Type II criteria or not. In autopsy cases, these sudden deaths have no exact cause of death but exclude SIDS. With the advancement of diagnostic techniques, some cases with previous and current diagnosis of SIDS may be diagnosed as metabolic diseases, heart diseases or other in the future. disease.
