(November 4, 2008 - Insidermedicine) On a recent trip to Boston, we caught up with Dr. Jonathan Davis, MD, who is the Chief of Newborn Medicine and Director of the Clinical Research Center at the Floating Hospital for Children at Tufts Medical Center, and a Professor of Pediatrics at Tufts University School of Medicine. Dr. Davis' research interests involve development of novel therapeutic approaches to prevent neonatal lung damage, brain injury and invasive infections.
If I had a baby with a lung complication...
One of the things about which we are most concerned when babies are born is whether than can breathe adequately, that’s the ABCs of our resuscitative efforts, Airway and Breathing as being A and B, and that drives the whole system clearly, so we are paying a lot more attention to those things than we have in the past. There are two phases of babies with lung complications when they’re born; there’s a group of premature babies that we see whose lungs may be underdeveloped and not functioning properly for a variety of reasons, and then we also see it in full-term babies admitted to the newborn intensive care unit. In general people think of the newborn intensive care unit as being a premature unit for babies who just aren’t ready to be on their own yet, and while that is certainly the case in many instances, (there is a significant rise in the number of premature babies that we are taking care of, sometimes to very concerning levels), but also in full term babies, who can come out, expected to be absolutely fine, but all of a sudden they start breathing more quickly, they may be working harder to breathe using excessory muscles to do that, and then also their color is what we look at.
From a premature standpoint we often ask why these babies were born prematurely, is it that their lungs are just immature, and if so we have treatments we can give, either to the mothers if they can be brought in early enough (can give them doses of steroids before they deliver to try to help the lungs mature), but once the babies are born we have medications called pulmonary surfactan which is a milky detergent-like substance that can go into the lungs to help the babies breathe, but the hallmark treatment for premature babies and all babies who have difficulty breathing is ventilatory support. It may be as simple as giving them supplemental oxygen and things like CPAP (Continuous Positive Airway Pressure) where we attempt to distend the lung and help the babies keep their lungs open and ultimately sometimes we require intubation and mechanical ventilation of those babies. In the full-term babies it can also be due to infection, it can be due to too much fluid, especially after caesarian sections. (C-section rates in the U.S. are rising at an incredible rate; this is something that we are very concerned about. It has been suggested that the whole curve of normal deliveries has shifted from 40 weeks to 39 weeks in a ten year period in the U.S. As more C-sections occur, more babies have fluid in their lungs, and it may be more difficult to breate.)
We are also much more sensitive of viral and bacterial infections and many babies can develop these kinds of conditions as well (we don’t fully understand why it happens in many circumstances but we do know it happens and that is something to be more concerned about as well.
What sort of diagnostic testing is performed?
The physical exam is quite important, we do want to listen to make sure there is good air entry in both sides of the chest; sometimes when babies come out and take that deep breath and try to inflate their lungs and get air into a fluid-filled lung, some of those little air sacks can pop, they can develop a pneumathorax which can be life-threatening, and many times you don’t hear breath sounds quite well on one side, so a physical exam is quite important; we listen to the heart and feel the peripheral pulses and look at the peripheral perfusion, because many instances, if the babies have congenital heart disease and their hearts haven’t formed properly there’s a problem in the heart, that may be one of the first ways we find out – by finding that the baby’s color isn’t particularly good and they’re not breathing very easily, so it is important to do a complete physical exam.
Next is laboratory values where we look at blood gases to see how much oxygen they’re getting into their lungs and actually how much is getting from their lungs into their blood, how effectively are they blowing off carbon dioxide, is there acid building up because they’re not able to do either of those things particularly effectively.
Next is chest X-rays that also give us a lot of information about how the lung looks and how the heart looks, and if we are particularly concerned about the heart we can get an echocardiogram and look at that in much more detail.
If I had a baby with a lung complication, I would make sure that the best-qualified people are available to see the baby. If you’re in a smaller hospital, you want to make sure there’s at least a pediatrician there to evaluate the baby. If the pediatrician is concerned they can seek consultations from more advanced care at level 2 centers or level 3 centers. If it is a lung complication that can’t be treated effectively at a secondary hospital, transport to a neonatal intensive care unit staffed by people with specific expertise.