Adaptation to extrauterine life

Upon its entry to the air-breathing world, the newborn must begin to adjust to life outside the uterus.

It consists of the assessment of heart rate, respiratory effort, muscle tone, reflex irritability, and generalized skin color.

[1] Physiology: In utero, the placenta delivers oxygenated blood to the fetus through the umbilical vein.

As a result, much higher proportion of the right ventricle output flows into the pulmonary vessels than into the systemic circulation through the ductus arteriosus.

During this transition, some types of congenital heart disease that were not symptomatic in utero during fetal circulation will present with cyanosis or respiratory signs.

[3] Assessments/Interventions: Assessment and monitoring of vital signs and skin color are important in detecting cardiovascular issues in the infant.

The apical pulse rate should be auscultated for one full minute when the newborn is calm or sleeping.

Any irregular heart rate after the first few hours of life that is not related to crying or another outside factor should be monitored and evaluated.

Respirations begin when fetal aortic and carotid chemoreceptors are stimulated by the varying concentrations of oxygen and carbon dioxide.

Monitor signs of respiratory distress such as: nasal flaring, grunting, central cyanosis.

[1] Physiology: At birth, the newborn is cut off from the mother's glucose supply and will begin to rely on stored fat for energy.

In cases where feeding is delayed, the neonate can use lactate, free-fatty acids, and ketone bodies.

[1] Rooting and sucking reflex should be present and the neonate will eat small amounts frequently.

All vital signs should be within normal limits coinciding with the neonates presentation of calmness and satiation.

Assessments/Interventions: Monitor blood glucose level and encourage breastfeeding or formula feeding as early as possible.

Physiology: Newborns lack the ability of thermogenesis due to underdeveloped shivering mechanism.

"Brown fat" is specialized adipose tissue with a high concentration of mitochondria designed to rapidly oxidize fatty acids in order to generate metabolic heat.

The neonates' arms and legs maintain a fetal position, lessening their body surface area and reducing heat loss.