Asphyxia Neonatorum

Definition

Definition of Asphyxia Neonatorum
Asphyxia neonatorum, also called birth or newborn asphyxia, is defined as a failure to start regular respiration within a minute of birth. Asphyxia neonatorum is a neonatal emergency as it may lead to hypoxia (lowering of oxygen supply to the brain and tissues) and possible brain damage or death if not correctly managed. Newborn infants normally start to breathe without assistance and usually cry after delivery. By one minute after birth most infants are breathing well. If an infant fails to establish sustained respiration after birth, the infant is diagnosed with asphyxia neonatorum. Normal infants have good muscle tone at birth and move their arms and legs actively, while asphyxia neonatorum infants are completely limp and do not move at all. If not correctly managed, asphyxia neonatorum will lead to hypoxia and possible brain damage or death.

Symptoms

Symptoms of Asphyxia Neonatorum
The symptoms of asphyxia neonatorum are bluish or gray skin color (cyanosis), slow heartbeat (bradycardia), stiff or limp limbs (hypotonia), and a poor response to stimulation.

Causes

Causes of Asphyxia Neonatorum
There are many causes of asphyxia neonatorum, the most common of which include the following: prenatal hypoxia (a condition resulting from a reduction of the oxygen supply to tissue below physiological levels despite adequate perfusion of the tissue by blood), umbilical cord compression during childbirth , occurrence of a preterm or difficult delivery, and maternal anesthesia (both the intravenous drugs and the anesthetic gases cross the placenta and may sedate the fetus). High-risk pregnancies for asphyxia neonatorum include:

1. maternal age of less than 16 years old or over 40 years old
2. low socioeconomic status
3. maternal illnesses, such as diabetes, hypertension, Rh-sensitization, severe anemia
4. mothers with previous abortions, stillbirths, early neonatal deaths, or preterm birth
5. lack of prenatal care
6. abnormal fetal presentation or position
7. alcohol abuse and smoking by the mother
8. severe fetal growth retardation
9. preterm labor

Diagnosis

Diagnosis of Asphyxia Neonatorum
Diagnosis can be objectively assessed using the Apgar score-a recording of the physical health of a newborn infant, determined after examination of the adequacy of respiration, heart action, muscle tone, skin color, and reflexes. Normally, the Apgar score is of 7 to 10. Infants with a score between 4 and 6 have moderate depression of their vital signs while infants with a score of 0 to 3 have severely depressed vital signs and are at great risk of dying unless actively resuscitated.

Treatment

Treatment of Asphyxia Neonatorum
The treatment for asphyxia neonatorum is resuscitation of the newborn. All medical delivery rooms have adequate resuscitation equipment should an infant not breathe well at delivery. Between 1970 and 2000, neonatal resuscitation has evolved from disparate teaching methods to organized programs. The most widely used procedure is the Neonatal Resucitation Program, supported by the American Academy of Pediatrics (AAP) and the American Heart Association (AHA).

If stimulation fails to initiate regular respiration in the newborn, the attending physician attempts resuscitation. He may decide first to gently suction the oropharynx-the area of the throat at the back of the mouth, with a soft catheter. When stimulation and a clear airway do not result in adequate respiration, the physician may give 100 percent oxygen via a face mask. If the infant is still not breathing, some form of artificial ventilation is then required. The usual method is to use mask ventilation with a resuscitator. The mask is applied tightly to the infant's face. If this procedure fails, the infant can be intubated with a endotracheal tube to which the resuscitator can then be connected. The more severe the fetal asphyxia, the longer it will take before the infant starts to breathe spontaneously. If the infant does not breathe despite adequate ventilation, or if the heart rate remains below 80 beats per minute, the physician can give an external cardiac massage using two fingers to depress the lower sternum at approximately 100 times a minute while continuing with respiratory assistance. Adrenaline may also be administered to increase cardiac output. Once the infant starts breathing, he or she is transferred to a nursery for observation and further assessment. Temperature, pulse and respiratory rate, color, and activity are recorded, and blood glucose levels checked for at least four hours.

Prognosis

Prognosis of Asphyxia Neonatorum
The prognosis for asphyxia neonatorum depends on how long the new born is unable to breathe. For example, clinical studies show that the outcome of babies with low five-minute Apgar scores is significantly better than those with the same scores at 10 minutes. With prolonged asphyxia, brain, heart, kidney, and lung damage can result and also death, if the asphyxiation lasts longer than 10 minutes.

Prevention

Prevention of Asphyxia Neonatorum
Anticipation is the key to preventing asphyxia neonatorum. It is important to identify fetuses that are likely to be at risk of asphyxia and to closely monitor such high-risk pregnancies. High-risk mothers should always give birth in hospitals with neonatal intensive care units where appropriate facilities are available to treat asphyxia neonatorum. During labor, the medical team must be ready to intervene appropriately and to be adequately prepared for resuscitation.