If you have a baby in the NICU there is a pretty good chance there will be at least one piece of plastic inserted into your child at some point. We have all sorts of “lines” and tubes that may be present depending on the conditions your baby develops. What follows is a primer on what they are all for.
I thought I would start with the easiest one since when you gave birth the team delivering you put one in you as well. The IV in the neonate is typically put in a hand or foot rather than the crease at the elbow as we like to save the bigger veins for something that we will talk about later on. Typically the IV provides sugar water (D10 most typically which is 10% sugar in water) to provide your baby with enough sugar to satisfy their metabolic needs. If a baby is older at birth but has difficulty breathing, having this type of access allows us to give them sugar and energy while not feeding them and letting their breathing settle. Putting food in the belly may sound like a necessity but they will be fine for awhile on dextrose which will allow their breathing to settle without having a full stomach pushing up on their diaphragm.
These come in two forms; the umbilical venous and arterial catheters. The easiest way to think of these are as long IVs like the one you may have had in your hand during delivery. These are long and on the venous side allow us to provide nutrition to your child either with sugar water (dextrose) or total parenteral nutrition (TPN). We can also give medications which can be tough on small veins in the hand or feet such as those to help with boosting blood pressure. The arterial catheter on the other hand allows us to monitor your baby’s blood pressure continuously. It also gives us a way of drawing blood when we need to test a number of things such as how your baby is breathing (an art gas) or checking their biochemistry such as when you hear us order “lytes” which checks salt and water balances in the body. By the way, putting these lines in does not hurt as there are no nerve endings in the umbilical cord.
These plastic tubes go from the nose (or mouth if it is an orogastric tube) into the stomach. When your baby is too preterm to know how to suck, swallow and breathe without inhaling their food it is safest to provide their milk through one of these tubes. They are very common!
When your baby is unable to breathe on their own they may need to be put on a ventilator. The ventilator attaches to an endotracheal tube and helps your baby get oxygen in and carbon dioxide out. These tubes can also be used very briefly to administer surfactant which makes it easier for your baby’s lungs to open and take air in. You may hear the medical team refer to the INSURE approach when using the tube in this way which stands for Intubate, Surfactant, Extubate.
Thankfully these tubes are not needed as much as they used to be. When air gets in between the lung and the chest wall we call that a pneumothorax.
This air can build up and make it very difficult for the underlying lung to open and fill with air. When that happens your baby’s oxygen levels drop and the carbon dioxide rises. These tubes will be put in to drain the air and relieve the pressure. Once they stop “bubbling” the tube will be clamped and then pulled out if no air reaccumulates. You may also see these tubes placed when a baby develops fluid in the same space called a pleural effusion. In that case you are trying to get rid of the fluid rather than air that has found its way in between the lung and the chest wall.
It’s Father’s Day so why not put out a post about a role for father’s in resuscitation. Given that we are talking about a parent being present for resuscitation after delivery and the mother will have just delivered, what follows is a discussion about having the other parent present at the ensuing resuscitation if needed. This will of course not always be a father as in female same sex parenting so what follows could apply to any situation in which there are two parents present and one has just delivered.
Since I was a resident this question has been batted around. During a resuscitation is it better to have families present or not? Certainly work has been done in this area which has demonstrated that from the families perspective this is a worthwhile pursuit. Families wish to be present and as a parent myself I would say it would be far more frightening to be kept out of the room than invited in to see what is going on. A mind can often conjure up scenarios that are far worse than actually exist if left to ourselves. I think in many centres now this is the case that families are invited into the room when their infant is being resuscitated but looking at things from another standpoint the question becomes what effect this has on the team doing the work? Does the team perceive that their workload is increased and if so could this affect performance?
An Answer to this question?
Dr. Schmölzer and his team in Edmonton (my former place of work) have atttempted to answer this question by looking at initial resuscitations in the delivery suite. Their study Does parental presence affect workload during neonatal resuscitation? used a tool I was unfamiliar with called the multidimensional National Aeronautics and Space Administration Task Load Index (TLX) survey to assess workload. After a resuscitation team members were invited to fill out the survey anonymously and in total 204 submissions were done. Degree of intervention after delivery included requiring stimulation 149 (73%) and suction 130 (64%), 120 (59%) continuous positive airway pressure, 105 (52%) positive pressure ventilation, 33 (16%) intubation, 10 (5%) chest compression, and 4 (2%) reported administration of epinephrine during resuscitation.
Results and Thoughts
Looking at the raw scores on the TLX the difference was highly significant in favour of having a parent present.
When further subdividing by apgar scores an interesting finding emerges in that as the apgar score increases the workload decreases. Even in the lowest apgar range the workload though appears to be equivalent.
I wonder if the finding results from being able to kill two birds with one stone? Part of the duty for any health care provider performing a resuscitation is to inform the parent of what is happening. When a patient is not doing well a provider might feel distracted and torn between providing the immediate care required and keeping the family abreast of what is happening. Having the family member present to see exactly what is going on reduces the amount of communication using descriptions and having to explain what they mean. Being able to point at an infant on CPAP and having respiratory distress for example is far easier with the parent present to point at the finding of indrawing than taking the time to explain it. I suppose the number of questions might even be lower in that circumstance. If a baby is quite ill at birth though and receiving chest compressions or epinephrine I would imagine it would be difficult to educate the family concurrently so explaining in detail what has been happening might be deferred to a later time point and hence the workload might be no different. What the data does suggest to me though is that in addition to previous research demonstrating benefits of families being part of the resuscitation for themselves, the team is no worse off in terms of workload and might even benefit from having them there as well.
The next logical study will look at resuscitations on the unit rather than in the case room but I think the question that was talked about as a resident can be put to rest.
If you have had a baby born prematurely and are reading this blog post you may have been told that the medical team is looking for a PDA. The PDA stands for Patent Ductus Arteriosus and the last two words Ductus Arteriosus really helped your fetus as it was growing in the womb. In order to understand how it can cause a problem after birth it is first important to understand what it did and why it exists in the first place.
Act I – The Womb
When your baby was developing its lungs the tissue was busy branching into airways that ended in little air sacs called alveoli. Each of those alveoli was next to a capillary which is our smallest blood vessels in the body. One day these units (alveolus and capillary) will happily exchange oxygen that is breathed in for carbon dioxide that needs to be breathed out. In the womb though the lungs were filled with fluid and air was nowhere to be seen. As such, most of the blood (about 90%) that came back from all the veins in the body to the right side of the heart had no business going to the lung. There was just not really any point in sending blood to the lung when it couldn’t pick up any oxygen there. The fetus by having a ductus arteriosus had a “pop off valve”. Since the pressure in the lung was high instead of sending blood to the lung, the 90% went from the right ventricle in the lower part of the heart to the pulmonary artery and from there across the ductus arteriosus to the aorta. The blood following this path therefore basically bypassed the lung and went from the “right” side of the heart to the “left” side that normally sends blood with oxygen to the rest of the body. The oxygen in this case came from the placenta. This fetal ciruculation is shown in the figure below.
Act II – Life on the outside
After birth the lungs fill with air containing oxygen and the resistance to blood flowing into the lung decreases which is a good thing as it allows oxygen to move from the alveolus to the capillary and back to the left side of the heart. As oxygen in the blood stream rises this usually leads to closure of the ductus arteriosus. In preterm babies though the ductus may not shut and this is what we call a Patent Ductus Arteriosus or PDA. This becomes a problem when the blood pressure in the aorta is high and the pressure in the lungs falls with breathing of air. Eventually, instead of the right to left flow of blood that occurred before, you now get blood flowing from the aorta to the pulmonary artery going to the lung and as more and more blood flows to the lungs they start to look white on chest x-rays and it gets harder and harder for your baby to breathe. The mixing is shown below.
Act III -So what do we do about it?
If we suspect that there is a PDA your doctor will order a test called an echocardiogram. This is an ultrasound of the heart and may be done by a specialist in the heart called a Cardiologist or may be done by a Neonatologist trained in doing such tests. Either way if the doctors believe the PDA is causing problems they will suggest a treatment plan to deal with it. The problems that would tend to motivate us to treat would most commonly be that your baby is needed support to help their breathing although problems related to poor blood supply to the kidneys might also lead us to treat.
The mainstays of treatment are two very common drugs and one that you may not have heard of. Indomethacin is a drug that was first used to help close PDAs and is a non steroidal anti-inflammatory (NSAID) drug that is in the same class as ibuprofen (advil) which is another drug that is used. In some centres another very common drug acetaminophen (tylenol) is employed. Most centres at this point are using one of the first two. Regardless after the medicines are given the doctors will order another echocardiogram to see if the PDA has closed and if not may repeat a course of the same medicine or choose a different one.
Act IV – What do you do if it just won’t close?
The next steps depend on how your baby is tolerating the PDA. If your infant is breathing on their own and their kidney function is working well many doctors will just observe and not offer more treatment. Babies though who are on a ventilator or are having significant issues related to their kidneys may rarely need to have a surgeon put a clip on the PDA to close it. These days this is quite rare and there are some centres that choose to not treat the PDA with medicine or surgical closure at all and just wait it out until they are gone. Almost 90% of them will close on their own if you leave them alone but again it depends on how sick your infant is in order to determine if this is reasonable.
If you are reading this and have a baby in the NICU with respiratory distress syndrome (RDS) otherwise known as hyaline membrane disease you might be surprised to know that it is because of the same condition that modern NICUs exist. The newspaper clipping from above sparked a multibillion dollar expansion of research to find a cure for the condition that took the life of President Kennedy’s preterm infant Patrick Bouvier Kennedy. He died of complications of RDS as there was nothing other than oxygen to treat him with. After his death the President committeed dollars to research to find a treatment and from that came surfactant and modern ventilators to support these little ones.
What is surfactant and what is it’s relationship to RDS?
When you take a breath (all of us including you reading this) oxygen travels down your windpipe (trachea) down into your lung and goes left and right down what are called your mainstem bronchi and then travels to the deep parts of the lung eventually finding its way to your tiny air sacs called alveoli (there are millions of them). Each alveolus has a substance in it called surfactant which helps to reduce the surface tension in the sac allowing it to open to receive oxygen and then shrink to get rid of carbon dioxide that the blood stream brings to these sacs to eliminate. Preterm infants don’t have enough surfactant and therefore the tension is high and the sacs are hard to open and easily collapse. Think of surface tension like blowing up those latex balloons as a child. Very hard to get them started but once those little balloons open a little it is much easier! The x-ray above shows you what the lungs of a newborn with RDS look like. They are described as having a “ground glass” appearance which if you recall is the white glass that you write on using a grease pencil when you are using a microscope slide. Remember that?
Before your infant was born you may have received two needles in your buttocks. These needles contain steroid that helps your unborn baby make surfactant so that when they are born they have a better chance of breathing on their own.
Things we can do after birth
Even with steroids the lungs may be “sticky” after birth and difficult to open. The way this will look to you is that when your baby takes a breath since it is so difficult the skin in between the ribs may seem to suck in. That is because the lungs are working so hard to take breath in that the negative pressure is seen on the chest. If your baby is doing that we can start them on something called CPAP which is a machine that uses a mask covering the nose and blows air into the chest. This air is under pressure and helps get oxygen into the lungs and gives them the assist they need to overcome the resistance to opening.
Some babies need more than this though and will need surfactant put into the lungs. The way this is done is typically by one of two ways. One option is to put a plastic tube in between the vocal cords and then squirt in surfactant (we get it from cow’s or pigs) and then typically the tube is withdrawn (you may hear people call it the INSURE technique – INtubate, SURfactant, Extubate). For some babies who still need oxygen after the tube is put in they may need to remain on the ventilator to help them breathe for awhile. The other technique is the LISA (Less Invasive Surfactant Administration). This is a newer way of giving surfactant and typically involves putting a baby on CPAP and then looking at the vocal cords and putting a thin catheter in between them. Surfactant is then squirted into the trachea and the catheter taken out. The difference between the two methods is that in the LISA method your baby is breathing on their own throughout the procedure while receiving CPAP.
Even if no surfactant is given the good news is that while RDS typically worsens over the first 2-3 days, by day 3-4 your baby will start to make their own surfactant. When that happens they will start to feel better and breathe easier. Come to think of it you will too.
Things are tough out there. If you are pregnant you no doubt have lots of questions about living and ultimately giving birth during this difficult time. These guidelines are from Alberta and like with everything these days are subject to change. As of March 23, 2020 this is what is being recommended if you live in Alberta. There are many good things here that are universal no matter where you live. Social distance, wash your hands, avoid touching your face and stay at home if possible.
Once upon a time we would use our gut instinct to inform our decisions as to whether it was reasonable to try and extubate (take out a breathing tube) or to lower or stop CPAP (continuous positive airway pressure). We used to look at home much oxygen a baby needed and what the pressures were on the machine offering them support and combined with what we saw on the patient monitor for oxygen saturation make a decision as to what to do next.
In the last decade or so people realized (as did one of our own respiratory therapists) that buried within all of this data on the patient monitor one could get a report on what percentage of time each infant has spent at different levels of systemic oxygen saturation. A sample report might look like this.
>95% – 10%
90 – 94% – 55%
85-89% – 20%
80 – 84% – 10%
<80% – 5%
Seeing this report though is only half the story. Without knowing how much oxygen on average an infant has received in the last twenty four hours to achieve this range it is somewhat meaningless. The amount of oxygen given may show that we the baby is doing better or worse. For example, if the above histogram was achieved using a range of 25-35% oxygen and was no different than the day before but the infant had been on 30-40% oxygen and pressure the day earlier then we have gotten somewhere! This infant has actually improved. The histogram is unchanged but we have given less oxygen on the same amount of pressure. If the histogram was unchanged but the amount of oxygen was 21-25% the day before, the lungs have gotten worse assuming the same pressure.
It is also worth noting that higher numbers are not alway indicative of a good thing. Take for example this histogram:
>95% – 50%
90-94% – 35%
85-89% – 8%
80-84% – 7%
<80% – 0%
If this infant was on room air and having these numbers I would be overjoyed. What if this was a baby though who was on 30-40% oxygen? These numbers are too good! We know that too much oxygen can be bad for the lungs and eyes. For babies on oxygen we typically target 88-92 % oxygen saturation (others use 90-94%). If we have 50% of the time above 95% oxygen we clearly are using too much and have to cut it back.
As parents you will hear us talk about histograms on rounds and use the information to make decisions about oxygen and the amount of breathing support your baby needs. If you have wondered how we use this information and what this seemingly random assortment of numbers really means, this is how we interpret it. The next time someone says that your infant needs more or less support ask for the histogram information if your unit uses it and you will see whether the data support the change.