The health of an infant can be determined in various ways, whether by outward appearance or clinical situations that require detailed observation. The measurement of oxygen saturation can show how healthy an infant is, or it may point to a potential health problem. Oxygen saturation is part of an assessment of vital signs for an infant, particularly those that may have respiratory distress or are in the neonatal intensive care unit.
Oxygen Saturation
Oxygen saturation measures the quantity of hemoglobin in the blood that is saturated with oxygen. Hemoglobin is a component of red blood cells that binds with oxygen and transports it to outlying tissues. Oxygen saturation is measured by pulse oximetry, which is an infrared light source that measures data. A pulse oximeter is typically wrapped around an infant's foot or hand to obtain a measurement.
Normal Levels
A healthy baby that is born full term should have oxygen saturations of 95 to 100 percent. Some institutions may have slightly different parameters. Depending on the need for supplemental oxygen after birth, term infants may only need to have oxygen saturations between 92 and 96 percent, according to Merck.
Respiratory Support
Babies that are born preterm are allowed to have lower oxygen saturations initially, based on lung development and reducing the incidence of retinopathy. Normal values for preterm infant oxygen saturations are 84 to 90 percent. An infant that is unable to maintain a minimum oxygen saturation level for his gestational age may be placed on supplemental oxygen. A physician can then continuously monitor saturation levels and adjust the oxygen in order to maintain a therapeutic range.
Hypoxemia
Infants with oxygen saturations below a normal level are considered to have hypoxemia. For an infant that is not wearing a pulse oximeter, hypoxemia may not be readily apparent. Low levels of oxygen in the blood can result in cyanosis, which is a blue color around the mouth. Low oxygen amounts in a full-term infant that can produce cyanosis may require a drop in saturations to 75 percent or lower when checked by pulse oximeter.
Retinopathy of Prematurity
There are some situations where maintaining lower oxygen saturations may be acceptable. Because lung tissue is one of the last developments in a fetus, premature babies frequently require supplemental oxygen. Treatment with high amounts of oxygen has been associated with retinopathy of prematurity (ROP), an eye disease that causes scarring of eye vessels and can lead to blindness. Adjusting supplemental oxygen to maintain saturations at lower levels has been shown to decrease the occurrence of ROP. According to research by the University of Michigan Department of Pediatrics, maintaining oxygen saturations between 70 and 90 percent for some premature infants reduced the amount of ROP.
References
- American Association of Critical Care Nurses: Oxygen Saturation Monitoring by Pulse Oximetry
- Children's National Medical Center: FAQ
- Merck: Respiratory Support in Neonates and Infants
- University of Michigan: Evidence-based Pediatrics Website
- Lippincott's Nursing Center: Hypoxemia in the Term Newborn
