Bubble CPAP (Continuous Positive Airway Pressure) is a non-invasive respiratory support for newborns with breathing difficulties. Unlike mechanical ventilation, which requires inserting a tube into the airway, this method provides gentle pressure to help a spontaneously breathing infant maintain lung volume. This approach is often used in neonatal intensive care units (NICUs), particularly for infants born prematurely.
How Bubble CPAP Works
The bubble CPAP system is a relatively simple apparatus designed to deliver consistent air pressure. It consists of a circuit of tubing that carries a blend of warmed, humidified air and oxygen to the infant. This gas mixture is delivered through a set of short, soft nasal prongs that sit just inside the baby’s nostrils or a small nasal mask.
An important part of the circuit is the expiratory, or outflow, tube. The end of this tube is submerged in a bottle of sterile water, and the depth of the tube in the water determines the amount of pressure in the system. As gas flows through the circuit and exits this submerged tube, it creates bubbles, which generates a stable, positive pressure back to the infant’s airways.
This process helps keep the small air sacs in the lungs, called alveoli, from collapsing when the baby breathes out. The bubbling action also creates small pressure oscillations or vibrations that are transmitted down the airways. These vibrations are thought to aid in gas exchange, making the therapy more effective.
Medical Conditions Treated with Bubble CPAP
Bubble CPAP is used to manage several respiratory conditions in newborns. Its most common application is for Infant Respiratory Distress Syndrome (IRDS), a condition seen in premature infants whose lungs are not yet fully developed. In IRDS, the infant’s lungs lack sufficient surfactant, a substance that prevents the alveoli from collapsing, and the continuous pressure from bubble CPAP helps keep these air sacs open, reducing the effort the infant must exert to breathe.
The therapy is also beneficial for Transient Tachypnea of the Newborn (TTN). This condition involves rapid breathing that appears shortly after birth and is caused by leftover fluid in the lungs. The positive pressure helps to push this fluid out of the alveoli, allowing the infant’s breathing rate to normalize more quickly.
It can also be used to support infants with Apnea of Prematurity, a condition where premature babies experience pauses in their breathing. While not a direct treatment for the cause of the apnea, the constant pressure can help stimulate breathing and maintain open airways. The use of non-invasive support like bubble CPAP is associated with a lower incidence of bronchopulmonary dysplasia (BPD), a chronic lung disease, compared to mechanical ventilation.
The Patient and Parent Experience
For parents, seeing their infant connected to a bubble CPAP machine can be concerning, but understanding the setup can help. In the NICU, you will notice the soft prongs in the baby’s nose, secured with a small dressing, and tubing connecting to the equipment. A distinctive and constant bubbling or gurgling sound from the water chamber is a normal part of the machine’s operation.
A common concern is irritation or skin breakdown around the baby’s nose from the prongs. To prevent this, the team will ensure the prongs fit correctly and may use special dressings to protect the skin. They also perform gentle suctioning to keep the nasal passages clear and may use an oro-gastric tube to decompress the stomach, which can prevent a distended belly from interfering with breathing.
Parents can still bond with and hold their baby. Skin-to-skin contact, often called kangaroo care, is encouraged while an infant is on bubble CPAP. The nursing staff can assist in positioning the baby and the equipment safely so that parents can hold their child. This physical closeness is beneficial for both the infant’s development and the parent’s emotional well-being.
Weaning from Bubble CPAP
The process of weaning an infant from bubble CPAP is gradual. The medical team will begin to consider weaning when the infant demonstrates stable breathing patterns and requires less supplemental oxygen. Specific criteria, such as the infant reaching a certain postmenstrual age or weight and needing only a minimal amount of extra oxygen, often guide this decision.
Weaning involves slowly reducing the pressure delivered by the machine. This might be done by lowering the depth of the expiratory tube in the water, which in turn lowers the CPAP level. For example, the pressure may be decreased by one centimeter of water at a time over a set period.
Another approach is to have the infant take short breaks from the machine, allowing them to breathe on their own for increasing durations. The medical team will observe the baby’s breathing effort, heart rate, and oxygen saturation levels during this process.