A pulse oximeter is a small device that measures the oxygen levels in the blood, known as oxygen saturation (SpO2). It provides a quick and non-invasive way to assess how well oxygen is being distributed throughout the body.
What is a Pulse Oximeter and How it Works
A pulse oximeter is a compact, clip-like device often placed on a finger, toe, or earlobe. It operates by emitting two different wavelengths of light, red and infrared, through the skin. Hemoglobin, the protein in red blood cells that carries oxygen, absorbs these light wavelengths differently depending on whether it is oxygenated or deoxygenated.
The sensor detects the amount of light that passes through, and an internal processor calculates the percentage of hemoglobin saturated with oxygen. The device also simultaneously measures and displays the pulse rate, which is the number of heartbeats per minute.
Why Infants Need Pulse Oximetry
Infants, especially newborns, require pulse oximetry for various health screenings. It is widely recommended for newborn screening to detect critical congenital heart disease (CCHD), a heart condition that can cause dangerously low oxygen levels. Early detection allows for timely intervention and improved outcomes.
Pulse oximetry also helps monitor infants with respiratory issues such as bronchiolitis, asthma, or respiratory distress syndrome (RDS). For premature babies or those with chronic lung disease, continuous monitoring of SpO2 levels is used to adjust oxygen therapy and assess respiratory status. It can also identify sleep-related breathing disorders, like obstructive sleep apnea, by detecting oxygen drops during sleep.
Using a Pulse Oximeter on an Infant
To use a pulse oximeter on an infant, a specialized pediatric sensor is placed on the foot, big toe, or sometimes a finger, ensuring a snug but not overly tight fit. The sensor should be positioned so that the light emitter and detector are directly opposite each other on the infant’s skin. Ensure the infant’s skin is warm and movement is minimal for accurate readings.
The device will display two main readings: the SpO2 percentage and the pulse rate. For healthy infants, a normal oxygen saturation reading is between 95% and 100%. In the first 24 hours after birth, levels can be lower, ranging from 89%–97% for well-term and preterm infants. A consistent reading below 95% may indicate a health issue requiring evaluation.
Important Considerations for Infant Pulse Oximetry
While a pulse oximeter is a valuable monitoring tool, it does not serve as a diagnostic device and should not replace professional medical advice. Caregivers should contact a healthcare professional if an infant’s SpO2 readings are consistently low or if there are other concerning symptoms, such as difficulty breathing, irritability, excessive sleepiness, or a bluish discoloration of the lips or skin.
Device accuracy can be affected by factors such as excessive infant movement, poor circulation in the limb where the sensor is placed, or nail polish on the measurement site. To prevent skin irritation or burns, especially in premature or ill infants, avoid prolonged use on a single site and routinely check the skin under the sensor. Maintain device cleanliness according to manufacturer instructions.