Surfactant helps pre-term babies breathe

A pre-term baby is delicate. One of the reasons why is because they are prone to respiratory distress syndrome, a breathing disorder. The condition is more common in such infants because their lungs cannot make enough surfactant, a liquid that coats the inside of the lungs for easy breathing.

To improve their lung function, such newborns require surfactant therapy. Here is how surfactant works: The airways, or bronchi, deliver air into the lungs. When you breathe in, air travels down into the lower airways which divide into smaller and smaller branches or bronchioles. Eventually the air reaches the air sacs, or alveoli.

Alveoli are the tiny air sacs that make the lungs soft and spongy. Oxygen is transferred from the alveoli into the bloodstream. Oxygen molecules enter the blood through tiny blood vessels covering the surface of each alveolus. That is why it's important for the alveoli to have so much surface area: the larger the surface, the easier it is for oxygen to enter the bloodstream.

Surfactant, a naturally produced substance, is a kind of foamy, fatty liquid that acts like grease within the lungs. Without it, the air sacs open but have difficulty remaining open because they stick together. Surfactant allows the sacs to remain open.

Surfactant usually appears in the foetus's lungs at about the 24th week of pregnancy and gradually builds up to its full level by the 37th week. If a baby is born too early, the lungs may not have enough surfactant. Without surfactant, surface tension will cause the alveoli to collapse. The lungs will be stiff and a lot of pressure will be needed to get a small amount of oxygen into the lung.

If a premature baby is lacking surfactant, artificial surfactant may be given.

Surfactant is delivered using an artificial airway or breathing tube inserted into the trachea, or windpipe, either immediately at birth for extremely premature babies, or later once respiratory problems have revealed themselves. Surfactant is administered through the windpipe over the course of a few minutes.

During this time, the baby will be turned and moved to distribute the surfactant to all parts of the lung. Depending on the severity of the lung condition, surfactant may be administered more than once.

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