It’s not your fault. You come to the bedside often and there isn’t a lot to do while your infant is asleep. There are only so many games, news and social media posts to keep your attention and let’s face it the monitor attached to your infant is a big distraction.
Typically, babies will have their blood oxygen saturation monitored along with their heart rate and respiratory rate. Some babies will have other physiological parameters monitored such as the amount of exhaled carbon dioxide or the blood flowing through their brain (near infrared spectroscopy) but the first three are the most common.
What you need to understand about these monitors is that we set alarms for when we need to know if there is a problem. What you also need to understand is that these alarms while necessary so we know when a baby is in trouble, can also drive you crazy. Parents may become slaves to the monitor where they spend a great deal of the day staring at ever changing numbers. If your infant is a “swinger” meaning that for example their heart rate or oxygen saturation tends to fluctuate a lot this can mean a lot of noise all day long.
One of the things that influences the result on the monitor is something called the averaging time. Typically for us this is 8 seconds which means that the number at any given time being shown is not the number for that second but represents the average number over the last 8 seconds. Sometimes your infant will be referred for a special test called a sleep study to closely monitor their apneic events. Sometimes families are shocked when their infant who seemed to have one or two events a day suddenly is reported as having 30. That is likely because the sophisticated lab is using a 2 or 4 second averaging time. Your baby in this case hasn’t changed. The monitor has. Some of the things that can be asked of the team when you have a baby with frequent events are trying to rule out causes of these alarms that are not due to your child themselves. Is the nasogastric tube in the right place? Should it be changed if your infant’s problem is mostly low heart rate? Could it be that the probe being used to measure oxygen saturation is in need of being changed to a different limb or altogether a new probe used? Typically low heart rate limits are set to 100 BPM. Strictly speaking many would consider this bradycardia but another definition is having a heart rate that is >20% below a baby’s baseline. Some babies are born with a heart rate that is anywhere from 100-110 (normal is usually 120-160). Twenty percent below that could be 80 beats per minute. Should the alarm be lowered to that number from 100? If so many of these alarms will vanish.
Stop Thinking About The Day To Day
Lastly, I would encourage you to try and look at your baby’s progress every few days. The journey through the NICU has many ups and downs. It really is no different than a figure showing the stock market over the last many years. Individual days have their ups and downs but it is the trend over many days that matters. Try not to let the daily events ruin your day. Take a moment and ask your nurse to see how your baby is today compared to a few days or a week earlier. You might be reminded that a week earlier your baby was on CPAP and now is on room air. Overall if they are better try and let that balance out your thoughts and try to not stare at the monitor. It just might drive you crazy.
One of the most common conditions afflicting ex-preterm infants is chronic lung disease. Through advances in antenatal steroids, surfactant and modern ventilation we have done what we can to try and prevent this condition from occurring yet despite our best efforts CLD remains a common problem among those born at less than 1500g as is shown in the 2018 Canadian Neonatal Network data.
Primary prevention is of course the ideal strategy to reduce disease but when you try and your best and an infant still has chronic lung disease what is one to do? For now we bide our time focusing on nutrition and minimizing harm from ventilation. Something new is coming and I hope it comes soon.
Stem Cells to Heal BPD
My former colleague Bernard Thebaud has done much work already in this field. A recent review he was part of is a good starting point to bring you up to speed; Stem cell therapy for preventing neonatal diseases in the 21st century: Current understanding and challenges. As the field advances though and we continue to see additional animal trials such as the one I will discuss here, the interest in this field continues to grow. I was drawn to a recent paper on this topic as it is not dissimilar to another trial I wrote about in which stem cells were given via breastmilk intranasally to improve outcome after IVH; Can intranasal application of breastmilk cure severe IVH? In this new trial though instead of delivering stem cells in a cephalad direction they place the rat vertically to deliver the stem cells from wharton’s jelly to the trachea and damaged lung.
The results are quite impressive. Looking at the histology of the four different groups reveals the curative property of these types of cells.
In essence the lung tissue architecture at the alveolar level looks almost identical to normal rat lung on the far left if the stem cells are provided through the intranasal route.
Moreover, when one looks at the impact on the blood vessels in the lung using Von Willebrand Factor staining similar healing is observed.
Lastly, not only were the numbers of blood vessels recovered but the thickness of the smooth muscle was reduced to that of normal rats without BPD after such treatment.
Why is this so important?
Past research has delivered stem cell treatment to the alveoli through an endotracheal tube. What this demonstrates is that rats held in a vertical position can have stem cells delivered into the lung where they are sorely needed. Could one take an infant on CPAP who is developing signs of CLD and do the same? The day may be coming when we prevent such infants from being reintubated just for CLD in the future.
The road is long though and the use of stem cells in humans has not begun yet. The effects seen in this rat model are dramatic but will they translate into the same thing in the human? I believe so and am waiting ever so patiently for such trials to start in humans. If you are looking for the next big leap in Neonatology I suspect this is what we are looking at. The question now is when.
If there is one question that is asked more than any other it is this one. As I have told countless parents, few really expect to have a stay in the NICU so when it happens you are caught off guard. The normal period of bonding after birth is disrupted and as many families will say, they just can’t wait to go home. When a baby is born preterm though they have to get through many obstacles such as dealing with respiratory distress syndrome, need for CPAP and perhaps problems related to the pesky patent ductus arteriosus. For sure these apply to the babies who are quite preterm but even those who are born later such as between 32-36 weeks or others who are born at term but quite small (we call those intrauterine growth restricted or IUGR infants) have a few milestones to achieve before they can go home. Knowing these are needed may help you on your journey and are summarized here. Please note this applies to my practice and although I suspect will be close to others, there may be some differences depending on where you are.
The “Big Four”
Feedings by mouth
We sometimes confuse families I think when we say on rounds that their infant is on full feeds. What we mean by this is that there is no longer a requirement for any intravenous fluid supplementation. In order to go home though in almost all cases your infant will need to be free of a plastic tube that is either passing from the nose or mouth to the stomach (NG or OG tubes). There are some instances where families may be trained to provide these “gavage” feeds at home but this is the exception rather than the rule. To enable full oral feeding there may be some different nipple and bottle options tried as well as strategies for different frequency of feeding. Typically, babies will be given feeds every 2 or 3 hours (q2 or 3H) and then with time given more flexibility (semi-demand or cue based feeds). When you hear “ad lib demand feeding” that means that they can feed as much as they want and as often as they want to and that means home is close.
When a baby leaves the NICU they will need to travel in a car seat for safety. In order to properly fit in a car seat you need to be about 4 lbs or 1800g. For this reason most centers keep infants until they are about this size. If you have a baby born at 1200g and they need to gain 600g they usually will lose weight for a few days and regain to birth weight by a week or two. Average weight gain for preterm infants is about 15-20g/kg/day which means that after the first couple weeks it would take on average about 30 days to reach the 1800g mark.
Small babies don’t have a lot of fat to keep them warm. As such your small infant starts off life in an isolette or what others call an incubator. Infants are all different but you can expect to begin seeing babies trialed out of isolettes as small as about 1500g. There are many babies who can’t successfully get out into an open crib even up to 4-5 lbs. Don’t be frustrated by this. It will happen but until they can maintain their body temperature outside of an isolette between about 36.3 – 37.4 degrees they will not be able to go home.
As discussed in another post, irregular breathing from apnea of prematurity can last for some time. Units across the globe vary in their approach to dealing with such “events”. On the short end there are units that like to see three days without an event at rest before stopping monitors while others use a five day period and others even longer at 7 or 8 days apnea free. These dips in oxygen saturation and/or heart rate can be VERY frustrating to families. Events that occur with feedings are less worrisome but still usually require a day or two of monitoring before your doctor will let you go. Sometimes they can last for weeks even when feeding seems to have gotten on track. The good news is that they will end eventually.
Of course there are other specific reasons why infants will need to remain in hospital but if you keep track of these “big four” it will give you a rough idea of when home might be around the corner.