What Is Apnea of Prematurity?

Neonatal apnea refers to premature infants with apnea of more than 20 seconds, term infants with apnea of more than 15 seconds, or apnea of no more than 15-20 seconds, but with slowed heartbeat, blue or pale skin, and decreased muscle tone. If breathing occurs 5 to 10 seconds after the breathing stops, the symptoms such as slow heartbeat, blue or pale skin are called periodic breathing. Periodic breathing is benign and does not affect gas exchange due to short breathing stop times. Apnea is a serious phenomenon that can cause brain damage. Apnea is more common in preterm infants, and its incidence can be as high as 50% to 60%. The younger the gestational age, the higher the incidence.

Basic Information

Visiting department

Pediatrics

Multiple groups

premature baby

Common causes

Respiratory central hypoplasia, or hypoxia, infection, nervous system disease, metabolic disorders, gastrointestinal diseases, etc.

Common symptoms

Stopped breathing, slowed heartbeat, bruised or pale skin, decreased muscle tone, etc.

Causes of neonatal apnea

The causes of apnea are divided into:

Primary

Premature babies are caused solely by hypoplasia of the respiratory center.

Symptomatic

(1) Asphyxia, pneumonia, hyaline membrane disease, congenital heart disease, and anemia.

(2) Infections: sepsis, meningitis, etc.

(3) Central nervous system disorders Intraventricular hemorrhage and hypoxic-ischemic encephalopathy.

(4) Metabolic disorders Hypoglycemia, hyponatremia, hypocalcemia, and hyperammonemia.

(5) Gastrointestinal diseases Gastric and esophageal reflux, necrotizing enterocolitis.

(6) Others The ambient temperature is too high or too low; airflow is blocked due to excessive forward curvature of the neck.

Clinical manifestations of neonatal apnea

Neonatal respiratory airflow ceases for 20 seconds, with or without slowed heart rate or <15 seconds, with slowed heart rate. Children with apnea within 24 hours of birth may often have sepsis; premature babies with apnea within 3 days to 1 week after birth can be considered primary after excluding other diseases; Premature infants should look for the cause and rule out symptomatic. Apnea in all term infants is symptomatic.

Neonatal apnea test

Blood routine

Hematocrit and blood culture can identify anemia and sepsis. Blood biochemical examination can rule out electrolyte disorders and metabolic disorders.

2. Image inspection

(1) X-ray examination The chest X-ray can find lung diseases such as pneumonia, hyaline membrane disease, etc., and it can help the diagnosis of congenital heart disease. Abdominal radiographs can rule out necrotizing enterocolitis.

(2) Skull CT is useful in diagnosing intracranial hemorrhage and central nervous system disorders in newborns.

(3) Ultrasound examination Ultrasound of the skull can exclude intraventricular hemorrhage. Cardiac ultrasound is helpful in the diagnosis of congenital heart disease.

3. Polysomnography

By monitoring EEG and muscle movements, not only can different types of apnea be distinguished, but also the relationship between apnea and sleep phases can be pointed out, which is helpful for the diagnosis of the cause of apnea.

Neonatal apnea diagnosis

Diagnosis can be based on medical history, clinical manifestations, and laboratory tests.

High-risk children who are prone to apnea are admitted to the ICU and monitored by a monitor, which can diagnose apnea in time. Conditional units should use four-channel monitoring, namely ECG, respiratory monitoring, plus pulse oxygen saturation and thermal sensors under the nostrils. A thermal sensor under the nostril can record changes in airflow in the respiratory tract and help diagnose obstructive apnea.

Neonatal apnea treatment

If the cause of apnea can be found, the primary disease must be actively treated, such as correcting anemia and hypoglycemia.

Oxygen supply

Children with apnea need oxygen. Generally, a mask or hood can be selected. During the oxygen supply period, oxygenation needs to be monitored. PaO26.65 10.76kPa (50 80mmHg) pulse oxygen saturation should be maintained at about 90% to prevent hyperoxemia.

2. Increase incoming impulse

Giving a child a back support, bounce the soles of his feet, or other tactile stimuli during an episode often relieves the onset of apnea. Placing the child on a vibrating water bed can reduce the onset of apnea by increasing the sensory impulses of the vestibule and increasing the sensory nerve impulses of the respiratory center.

3. Drug treatment

(1) Theophylline or aminophylline The most commonly used therapeutic drugs are methylxanthines. Theophylline may directly stimulate the respiratory center or increase the sensitivity of the respiratory center to CO ₂ , increase the breathing frequency and reduce the onset of apnea. The mechanism is due to the inhibition of phosphodiesterase, increasing cAMP and catecholamine levels. Side effects of theophylline include tachycardia, hypotension, irritability, convulsions, hyperglycemia, and gastrointestinal bleeding.

(2) The mechanism of caffeine citrate is similar to theophylline, but it has a long half-life and low toxicity. Sodium benzoate caffeine is not used for apnea in preterm infants, as sodium benzoate can compete with bilirubin for albumin binding sites, increasing the risk of nuclear jaundice.

(3) Doxapram Respiratory central stimulant. It is reported in the literature that the treatment is effective when theophylline and caffeine treatments are ineffective. Disabled with cardiovascular disease or convulsions. Due to the need for continuous intravenous drip and its toxic effect, the application of this drug is limited.

4. Continuous Positive Airway Pressure (CPAP)

Generally, CPAP can be used in patients with apnea who can not be relieved by oxygen supply. Bilateral nasal congestion or endotracheal intubation is commonly used. The pressure is 0.3 ~ 0.5kPa. The mechanism may be related to the correction of hypoxia.

5. Mechanical ventilation

After some children are treated with the above methods and still have frequent apnea and are accompanied by hypoxemia or obvious bradycardia, mechanical ventilation can be used.

6. Drug evacuation and home monitoring

When the apnea eases, consider theophylline. If the apnea relapses after discontinuation, theophylline should be re-administered, and the medication can be maintained until 52 weeks after pregnancy or 4 weeks after birth if necessary.

Neonatal apnea prevention

Pregnant women should take good care of antenatal care, avoid heavy physical labor before giving birth, and avoid premature birth. Should go to the hospital for production, and closely observe the situation of children after delivery. If apnea appears, you should be rescued in time, use respiratory stimulants, inhale high concentrations of oxygen to treat the primary disease.