What does newborn resuscitation mean?
Rapid and effective neonatal resuscitation within seconds after birth is essential for the baby’s survival under these conditions.
Neonatal resuscitation is a procedure to stimulate and help newborn babies breathe if they do not start breathing spontaneously after birth. Some babies require only basic measures such as warmth, airway clearance, and gentle stimulation, but some may require cardiopulmonary resuscitation (CPR) with assisted ventilation and chest compressions.
Approximately 10% of all newborns in the United States require some assistance during the transition from fetus to newborn.
Why is neonatal resuscitation required?
Oxygen deprivation (asphyxia) during delivery because of compression of the umbilical cord, and extreme prematurity are two major complications of pregnancy that require intervention with neonatal resuscitation. Rapid and effective neonatal resuscitation within seconds after birth is essential for the baby’s survival under these conditions.
Neonatal resuscitation is performed to:
- Provide oxygen
- Stimulate respiration
- Stimulate cardiac function and adequate blood flow
- Maintain core temperature
- Maintain blood glucose levels
Several systemic changes take place before, during, and immediately after birth, which enables a baby to breathe and survive outside the uterus. If these systemic changes are delayed or inefficient due to prematurity or illness, neonatal resuscitation becomes necessary.
Two major systemic changes during fetal to neonatal transition are:
Respiratory adaptation
Fetal lungs are nonfunctional and the oxygen/carbon dioxide gas exchange takes place in the placenta. The fetal lungs, and the air sacs (alveoli) which develop after 20 weeks of gestation, are filled with fluid secreted by the inner lining of the lungs (pulmonary epithelium).
The change of position of the fetus before birth and the contractions during labor help expel some of the fluid in the lungs. Hormonal secretions during birth stop the secretion of fluid in the lungs and promote reabsorption and drainage of the remaining fluid.
A substance known as surfactant secreted in the lungs reduces the surface tension in the liquid/air interface in the alveoli and prevents them from collapsing with the removal of the fluid. The negative pressure created in the lungs with the elimination of fluid enables the baby to draw their first breath.
Sensors are known as mechanoreceptors sense respiratory muscle movements, and chemoreceptors that sense levels of oxygen, carbon dioxide, and pH levels activate. Feedback from the receptors stimulates the respiratory center in the brain, which drives and regulates continued respiration.
Cardiovascular adaptation
The fetus has a right-to-left blood circulation which starts changing to left-to-right, immediately after birth, when the baby draws its first breath. The fetal circulation is facilitated by two shunts in the heart and a shunt in the vein that brings oxygenated blood from the placenta. All three shunts close shortly after birth and fuse gradually.
- Foramen ovale: A small opening in the wall (septum) between the right and left chambers (atria) of the heart.
- Ductus arteriosus: A connection between the pulmonary artery and the descending aorta.
- Ductus venosus: A connection between the liver’s portal vein and the central vein, inferior vena cava.
In fetal circulation, oxygen-rich blood from the placenta flows through the umbilical vein to the fetus. Some of the blood perfuses the liver, but most of it bypasses the liver and flows into the inferior vena cava through the ductus venosus and into the right upper chamber (atrium) of the heart.
The blood then flows into the left atrium through the foramen ovale and into the left ventricle. Most of the blood flows through the aorta and the ductus arteriosus to the rest of the body, bypassing the lungs. The pulmonary vessels in the fetus are constricted and the lungs get a small amount of blood required for their development.
When the newborn takes the first breath, the oxygenation of the blood results in dilation of pulmonary vessels, and blood flow between the heart and the lungs increases. The pressure in the left heart chambers closes the one-way valves in the two heart shunts, the umbilical cord clamping closes the ductus venosus, thus establishing left-to-right circulation.
When should neonatal resuscitation be initiated?
Rapid assessment of the newborn’s condition immediately after birth is vital to decide on the need for neonatal resuscitation. The newborn baby will only need routine postnatal care if the following characteristics are present:
- The baby has completed full-term of gestation.
- The amniotic fluid is clear of meconium (baby’s first stool) and any signs of infection.
- The baby starts crying and breathing.
- The baby has a good muscle tone.
If the newborn fulfills all of the above criteria, delivery room staff will dry the infant and keep them warm, close to the mother. If any one of the above criteria is not met, doctors start neonatal resuscitation immediately.
What are the steps in neonatal resuscitation?
One or more of the following steps are taken in sequence, as needed, during neonatal resuscitation:
- Initial stabilizing include:
- Providing warmth
- Clearing the airway with suction
- Drying the baby
- Gently stimulating the baby to breathe
- Assisted ventilation with a gas mask or endotracheal tube to stimulate breathing and supply oxygen
- Chest compressions stimulate the heart to pump blood
- Administration of medications:
- Epinephrine to increase heart rate and blood pressure
- Saline solution to increase blood volume
What neonatal resuscitation techniques are controversial?
The Neonatal Resuscitation Program (NRP), a highly respected certification program for delivery room personnel, developed jointly by the American Academy of Pediatrics (AAP) and the American Heart Association (AHA) has standardized neonatal resuscitation procedures to a great extent.
Evaluation of neonatal resuscitation standards is an ongoing process and controversies continue to exist, which include the following:
- Room air versus 100% oxygen: Some studies have shown that resuscitation with room air, which has a concentration of 21% oxygen, is as effective as 100% oxygen. Furthermore, oxygen-free radicals can cause tissue injury. Current data, however, is insufficient to support the use of one or the other.
- Artificial surfactant administration: Surfactant deficiency is a primary reason for respiratory distress syndrome (RDS), especially in extremely premature infants. Controversy with surfactant administration relates to the timing of surfactant administration and its preventive use, which may be an expensive treatment for infants who do not need it.
- Researchers suggest that infants born earlier than 28 weeks of gestation should receive surfactant within the first few minutes of life and infants after 30 weeks of gestation should receive the therapy if they show signs of RDS.
- Intubation and suctioning for meconium aspiration: The NRP earlier recommended routine suctioning of all non-vigorous infants born in meconium-stained amniotic fluid as soon as the head is delivered. The current guidelines recommend suctioning only if thick meconium is present in the nose and mouth.
- Hypothermia: Some studies suggest that keeping the heads of asphyxiated infants slightly cool may reduce brain injury, but this conflicts with the fact that hypothermia prevention is essential for effective neonatal resuscitation and requires further study.
- Withholding and discontinuing resuscitation: Advances in technology have made it possible to improve the survival rate in extremely premature infants. Withholding or discontinuing resuscitation is a difficult decision complicated by viability and ethical considerations, and is made after counseling the parents and consulting with them.
When should neonatal resuscitation be stopped?
Current guidelines suggest discontinuing neonatal resuscitation if there is no detectable heart rate or respiration after 10 minutes of continuous and appropriate resuscitative efforts. Resuscitation may be continued up to 20 minutes in some infants based on:
- Presumed reason for cardiac arrest
- Gestational age of the baby
- Presence or absence of complications
- Potential role of therapeutic hypothermia
- Parental feelings about the acceptable risk of associated morbidity (medical condition or disease)
An individualized decision is made in each case of neonatal resuscitation, but current studies suggest withholding resuscitation efforts in infants with
- Gestational age lower than 23 weeks
- Birth weight less than 400 G
- Congenital anomalies with almost-certain early death such as:
- Anencephaly (absence of parts of brain and skull)
- Trisomy 13 or 18 (chromosomal abnormality caused by an extra copy of a chromosome that leads to serious physical problems)