When your clinical ends, Mr. B is resting peacefully. His respiratory rate and heart rate are back to normal, his chest tube is not bubbling anymore, and his breath sounds are even on both sides. Mrs. H is using her spirometer, and the respiratory tech says her vital capacity is a lot better than it was the first time he checked on her. The CNS tells your prof you made a good save in noticing Mr. B's tipped chest tube bottle. A great clinical all around! So you treat yourself to an after-class drink with a fellow student who spent her day in the NICU (neonatal intensive care unit).

"You won't believe what happened to me today! The transport from ER collapsed somebody's lung!"

"It must be lung day. We have a preemie in the NICU with collapsed lungs as well."

"Wow, what happened? Did it have a chest injury? Do they put chest tubes in babies?"

"No, she just never inflated them when she was born. The doctors keep talking about surfactant, but the mom didn't understand what that meant. She was so scared; I felt sorry for her. But I don't think I could explain it either!"

You are on a roll today, so help your friend come up with a clear explanation of what surfactant does.

Surfactant is a liquid produced by the alveoli in the lungs to keep the lungs from collapsing.

Explanation:

Surfactant is a fluid composed of lipids and proteins produced in the lungs that keeps the airways open and prevent the lung from collapsing. It is secreted by the alveolar epithelial type-II (AT-II) cells of the tiny air sacs found in the lungs called alveoli. It prevents the collapse of alveoli under the surface tension by reducing the surface tension at the interface between air and the aqueous fluid lining the alveolar surfaces.  If enough surfactant is not present, the surface tension causes the tissue surrounding the alveoli to stick together after each exhalation and results in the collapse of alveoli.

Usually, in unborn babies, the production of surfactant starts at about 6 months of pregnancy and the surfactant helps the babies to breathe in the air immediately after delivery. But a premature baby can not produce enough surfactant and it results in the collapse of alveoli with each breath. The damaged alveolar cells collected in the airways affect breathing and the baby takes in less oxygen. This disorder is known as respiratory distress syndrome (RDS).

The level of carbon dioxide in the blood increases and results in acidosis which affects other organs in the body. Since the premature babies having RDS need extra oxygen and help with breathing, the treatment methods include providing extra oxygen through CPAP, placing a breathing tube into your baby's trachea, providing artificial surfactant and ventilator support.

c: warm water flows from the western tropical pacific toward south america. that should be the right answer! hope it .