Surfactant in Prematurity – Making Preme’s Life Better
One of the great things about writing these “current development” blog entries is that I get to read lots and lots of interesting medical articles about all kinds of things, big and small.
Everyone knows that tremendously-huge strides have been made in treating, and saving, premature infants in the past 10 years. Techniques have improved, methods have been altered and interventions developed to the point that now it is not uncommon to see rows of isolettes in the newborn intensive care unit containing the very smallest of human beings who are surviving prematurity against substantial odds.
What you may not know is that probably one of the most important things that started making this possible is a substance called “surfactant.” It’s a soap-like substance secreted by the cells in a persons lungs which keeps the tiny air sacks from collapsing and sticking together. The problem arises when a fetus is required to actually use their lungs before the cells are ready to do their “secreting.”
The discovery of surfactant, then its synthetic production along with more effective mechanical ventilation (MV) was a god-send to pediatricians trying to keep these infants alive. But, how do you get it down inside the lungs where it is needed? First we tried misting then flushing and squirting and now we are much, much more professional about it.
And what causes the subtle smile of satisfaction on this old guys face is the observation that now the majority of new articles coming out aren’t so much about using surfactant but how to use it better! When a treatment graduates from arguments about “whether” to do it to “how” to do it, you know we’ve progressed really far.
If a baby is not breathing on it’s own at all, of course the treatment is mechanical ventilation and surfactant can be instilled into the lungs through the endotracheal tube (ET Tube). All those pressure fluctuations are tough on the lungs however and often cause scarring (or something like callouses) inside which “weaken” them for years to come toward breathing difficulties.
If a baby is ventilating on its own we would rather avoid any excess pressure at all if we could; but, how then to instill the surfactant? A technique called “InSurE,” standing for Intubate, Surfactant, Extubate, was developed, tested, found to work and has been the treatment standard for years. A “tube” is placed for a short time and surfactant is installed followed by 30 seconds of mechanical ventilation before placing back on the less invasive nasal continual positive pressure (nCPAP).
An article in Pediatrics, the official journal of the American Academy of Pediatrics (Jan 28, 2013), reports that some doctors in Turkey have completed a study where a slightly different technique was used to instill the surfactant in half of the studies’ 200 infants. They call it the “Take Care” method and it involves placing only a small tube to instill the surfactant, instead of the ET tube, while the baby continues to breath on its own without any mechanical ventilation.
The exciting finding is that in the first 72 hours of life the Take Care group needed significantly less mechanical ventilation (30% vs 45%) AND when it was used it was for a significantly shorter time. Not only that, the rate of babies with Bronchopulmonary dysplasia (the scarring I mentioned) was clearly lower.
And it’s nice to know that physicians in the U.S. have also used the less invasive technique with good results, as well as Australian physicians who use an even smaller vascular catheter and call it “MIST” – Minimally Invasive Surfactant Administration.
You’ve come a long way baby!
[Pediatrics 2013;131:e502-e509]