The Neonatal Intensive Care Unit (NICU) is a specialized environment where newborns receive intensive medical care, often for conditions that affect their ability to breathe effectively. Respiratory support, including the use of supplemental oxygen, is one of the most common treatments provided to these patients. When a baby requires oxygen, it can be a source of anxiety for parents, who may worry about the necessity of the intervention and its long-term implications. Understanding the reasons for oxygen therapy and the methods used to administer it helps demystify this standard practice. This article clarifies the process of oxygen support, covering the medical necessity, daily monitoring, and the eventual goal of breathing room air.
Why Supplemental Oxygen is Essential for Neonates
A newborn requires supplemental oxygen when their lungs cannot effectively transfer enough oxygen into the bloodstream to meet the body’s demands. This state of low oxygen, known as hypoxemia or hypoxia, can damage vital organs like the brain and heart, making intervention necessary to preserve normal development. Oxygen delivery is carefully managed to ensure adequate tissue oxygenation while avoiding harm from excessive oxygen.
Premature birth is a primary reason infants require oxygen therapy because their lungs are immature and lack sufficient surfactant, a substance that keeps the tiny air sacs open. This deficiency causes Respiratory Distress Syndrome (RDS), where the alveoli collapse, making breathing difficult. Supplemental oxygen, often combined with synthetic surfactant administration, helps these lungs function until they mature naturally.
Other conditions also necessitate oxygen support, such as Persistent Pulmonary Hypertension of the Newborn (PPHN). In PPHN, the blood vessels in the lungs remain constricted after birth, preventing proper blood flow and oxygen uptake. Oxygen acts as a potent pulmonary vasodilator, helping relax and open these vessels, thereby improving blood flow to the lungs. Apnea, involving brief pauses in breathing that cause drops in oxygen levels, is another common concern that supplemental oxygen helps manage by stimulating the respiratory drive.
Methods of Oxygen Delivery in the NICU
The method of oxygen delivery depends on the baby’s medical condition and the level of breathing assistance required.
Non-Invasive Support
For babies who can breathe strongly but need a slight boost, a simple nasal cannula may be used. This involves a thin, soft tube with two prongs that sit gently inside the nostrils to deliver a controlled flow of oxygen-enriched air. Another non-invasive option is the oxygen hood, a clear plastic dome placed over the baby’s head, which delivers a warm, humidified oxygen mixture.
Continuous Positive Airway Pressure (CPAP)
When more significant support is needed, but the baby still initiates their own breaths, CPAP is often the next step. CPAP delivers a constant pressure of air or oxygen through a mask or short nasal prongs. This pressure acts as a pneumatic splint, keeping the airways and alveoli from collapsing during exhalation. CPAP reduces the baby’s work of breathing without taking over the function of their respiratory muscles.
Mechanical Ventilation
The most comprehensive form of breathing support is mechanical ventilation, used when an infant is too weak or sick to breathe adequately on their own. This involves placing a small endotracheal tube into the baby’s windpipe, which connects to a ventilator machine. The ventilator is programmed to deliver precise amounts of air and oxygen at set pressures and rates, breathing for the baby while their lungs heal or develop.
Monitoring Oxygen Levels and Managing Saturation
Managing supplemental oxygen requires continuous monitoring to ensure the baby receives the correct amount. The primary tool for this is the pulse oximeter, a non-invasive sensor placed on the baby’s hand or foot, which measures peripheral oxygen saturation (SpO2). This measurement indicates the percentage of hemoglobin in the blood carrying oxygen.
The pulse oximeter connects to a bedside monitor that displays the SpO2 reading and sounds an alarm if the level moves outside a predetermined, safe range. For many neonates, particularly premature infants, the target saturation range is typically maintained between 90% and 95%. This range is selected because levels below the lower limit risk hypoxia, while levels above the upper limit risk complications from hyperoxia.
The process of adjusting the oxygen flow to keep the SpO2 within the target range is called titration. Nurses and respiratory therapists constantly titrate the oxygen, increasing the flow if saturation drops or decreasing it if saturation rises too high. Alarms are a normal and frequent part of the NICU environment, serving as an early warning system that allows the care team to promptly make these adjustments.
Potential Complications and Weaning Off Oxygen
While oxygen therapy is necessary, prolonged exposure can present risks to a developing neonate. Two primary concerns associated with extended oxygen use are Retinopathy of Prematurity (ROP) and Bronchopulmonary Dysplasia (BPD).
Retinopathy of Prematurity (ROP)
ROP is an eye condition involving abnormal blood vessel growth in the retina, primarily linked to high or fluctuating oxygen saturation levels in extremely preterm infants.
Bronchopulmonary Dysplasia (BPD)
BPD is a form of chronic lung disease that develops when immature lungs are exposed to prolonged mechanical ventilation and high oxygen concentrations. This exposure can damage developing lung tissue, leading to inflammation and scarring. Modern NICU protocols, involving careful titration and maintaining saturation within a tight target range, are designed to minimize the risk of both ROP and BPD.
The ultimate goal of oxygen therapy is to wean the baby off support entirely as their lungs mature and their medical condition improves. Weaning is a gradual process where the amount of pressure or percentage of oxygen is slowly decreased over time. The care team transitions a baby through stages: from a ventilator to CPAP, then to a nasal cannula, and eventually to breathing room air without assistance. For some babies, especially those with BPD, weaning may take months, and they may be discharged home with supplemental oxygen that is gradually reduced according to a structured plan.