All right, welcome back to our cyanotic congenital heart defects. So our ones with our decreased pulmonary blood flow is our Tetralogy of Fallot, or Tet is another nickname for it, tricuspid atresia, and truncus. We also have our mixed blood flow, transposition, total and almost pulmonary venous return, or TAPVAR, hypoplastic left heart syndrome, or HLHS. So what are our signs and symptoms? Cyanosis, in the name of cyanotic congenital heart defects, desaturation, congestive heart failure, feeding intolerance.
What is our general care? Air emboli precautions. We also expect those saturations to be much lower, usually less than 90%. Sometimes we actually make those kids saturations lower by adding, like decreasing the oxygen in the air by adding nitrogen.
We also have our, again, we want to maintain that cardiac output, which is our heart rate times our stroke volume. We want to decrease the O2 and metabolic demands. So keep them normal thermic and treat infections. We got to be cautious with that oxygen.
I know most of the time we want to increase the oxygen to maintain those saturations. But with our cyanotic congenital heart defects, we actually don't. Those, remember that patent ductus arteriosus? We have to maintain a lower oxygen saturation to keep that open. We also utilize medications to help keep that ductus arteriosus open as well.
All right, first we're going to go into our tetralogy of Fallot. So these are, I would highlight the four defects of our tetralogy of Fallot. This is something that you should remember.
We have a large ventral septal defect or large VSD. We have a right ventricular. outflow tract obstruction. We have overriding aorta and right ventricular hypotrophy. The degree of cyanosis is largely dependent on the degree of obstruction to the pulmonary blood flow and is reflected in the saturation.
So again, the degree of cyanosis is largely dependent on the degree of obstruction to the pulmonary blood flow and is reflected on in the saturation. With minimal pulmonary stenosis, a large left to right shot may be present, which results in what's called a pink tet. With severe right ventricular outflow obstruction, the infant will be very cyanotic with ductal dependent pulmonary flow. This is what we call a blue tet.
Tet spells are something that happens with tetralogy of Fallot. These usually happen with our blue tet. So a tet spell needs to be well managed.
Maintain a quiet and calm environment. Allow family at the bedside. Provide comfort measures as first sign of agitation to prevent these spells.
The positioning for hypersinosis or tet spells would be a knee to chest position, which increases the preload by pushing lower extremity blood back to the heart. This also increases afterload by rising systematic vascular resistance altogether. Thus, this increases our cardiac output to the lungs.
A little oxygen may also help decrease the pulmonary vascular resistance. So tet spells or hypersynosis spells need a chest, calm environment, avoid agitation, 100% oxygen, and then we also can utilize medications to help with that preload and afterload. Tricuspid atresia.
This is where the tricuspid valve fails to develop. Consequently, there is no communication from the right atrium to the left right ventricle. Blood flows through the atrial septal defect or patent foramen ovale to the left side of the heart and through a VSD to the right ventricular and out to the lungs. At birth, the presence of a patent foramen ovale or other atrial septal opening is required.
to permit blood flow across the septum and to the left atrium. The patent ductus arteriosus allows blood flow to the pulmonary artery and into the lungs for oxygenation. A VSD allows a modest amount of blood to enter the right ventricular and pulmonary artery for oxygenation.
Pulmonary blood flow is often diminished. Cyanosis is usually seen in the newborn period. There may be tachycardia and dyspnea. Tachycardia is systematic.
Blood flow is dependent on the... patent ductus arteriosus, then prostaglandin will be needed. Truncus.
The aorta and pulmonary artery leave the heart as a common trunk. There is a large ventral septal defect, which the truncus overrides. Intracardiac mixing of the systematic and pulmonary venous return, usually pulmonary overcirculation, which increases in pulmonary blood flow, early pulmonary obstructive disease may result.
There's complete mixing of the blood, as you can see. Even deoxygenated blood is entering and then oxygenated blood is entering the left side of the heart. But they mix right here with that ventricle septal defect.
A third of the infants with truncus have what's called DeGeorge syndrome. And their saturation is lower. So truncus saturation is 75 to 85 percent.
Highlight that if you need to. You want to monitor these patients for pulmonary overcirculation or congestive heart failure. This could be bounding pulses, tachypnea, dyspnea with feeds, and diaphoresis. Transposition of the great arteries.
So the aorta is anterior and the right arises from the left ventricle. The pulmonary artery is posterior and leftward and arises from the left ventricle. may be accompanied by associated defects such as a VSD, pulmonary stenosis, or coarctation. The aorta is supposed to supply oxygenated blood to the body.
Instead, it returned the oxygenated blood to the system. Circulation with the pulmonary artery returns oxygenated blood to the pulmonary circulation. Thus, there are two parallel circulations. As you can see, deoxygenated blood is entering, deoxygenated blood is leaving.
Ah, go back. Sorry about that. And then oxygenated blood is entering and the oxygenated blood is going back into the lungs.
So this is a ductal dependent lesion. So again, two parallel circulations. They will have lower saturation pre-ductal in the right arm and post-ductal, which is reverse differential cyanosis. So again, pre-ductal is usually the one that is higher.
So your right arm is usually higher. But in this situation, it actually may be lower. Systematic oxygenation is dependent on mixing.
This can occur at the patent foramen ovale. So if we have this patent foramen ovale between the atriums open, then their mixing can occur. And then also at the patent ductus arteriosus. So we need to have the one or both of those open to make sure that we get some oxygenated blood to the body. Again, this is a ductal dependent lesion.
The patent for amenovalia is restrictive. A balloon atrial septostomy, which is a heart cap, they pump up a balloon and then they pull it through to keep that hole open in the heart. You must have prostaglandin to keep the ductus arteriosus open in patent.
Total anomalous pulmonary venous return, TAPVAR. This is failure of the pulmonary veins to drain into the left atrium. Flow to the body requires right to left shunting across the associated atrial septal defect.
No obstruction to atrial mixing. Symptoms may be mild. If there's an obstruction to pulmonary venous return, cyanosis may be severe and acidosis may be profound.
Blood flow is left to right. Atrial septal. defect or patent foramen ovale must be present for the mixing. Infants will present with varying degrees of cyanosis. Obstructive pulmonary venous return is a surgical emergency.
As you can see, there is just lots going on in here. But again, obstructive pulmonary venous return is a surgical emergency. Hypoplastic left heart syndrome.
This is usually diagnosed around the 20-week ultrasound. as they can look at the heart and see what's going on. This is again one of the reasons that the 20-week ultrasound is really important. They can see a lot of these different conditions.
That way parents can be prepared and deliver at the right center for their child and themselves. Hypoplastic left heart syndrome is a constellation of defects characterized by a diminutive left side of the heart. The left ventricle is small as you can see on the screen. Left atrium is usually small The aorta is hypoplastic to varying degrees.
There may be an aortic or mitral valve stenosis or atresia. A patent foramen ovale and a patent ductus arteriosus are also present. Blood flow to the aorta, the arch, and the coronaries depend on the patent ductus arteriosus.
Left to right shunting through the patent foramenal valley, which increases pulmonary flow, and pulmonary venous returns increase to the small left atrium. Respiratory distress, mild cyanosis is present in the first 24 to 48 hours. Saturation may be normal, but systematic perfusion is decreased, often with weak fetal pulses and poor urine output. This is a ductal dependent lesion and we will need prostaglandin to maintain systematic perfusion and prevent metabolic acidosis.
In order to maintain balance to circulation and assure flow to the body, oxygen is minimized and saturation is maintained less than 90%. Nitrogen may be administered to deliver sublimate O2 that is less than 18%. Pulmonary overcirculation can result in respiratory distress and pulmonary edema. Increased flow to the lungs can also decrease blood flow to the coronaries.
NIRs are monitored to assess cerebral and kidney perfusion. Urine output, bun, creatinine, and lactate are monitored for systematic perfusion. So NIRs is just a different way. They usually put one on the brain and the one on the body to assess the perfusion in cerebral or kidneys.
All right, so we're going to go into a little bit of dosage calculations. Since we're talking about our cyanotic congenital heart defects, a lot of them will need prostaglandin. So first, what is prostaglandin?
Prostaglandin is, if you remember back into that first cardiac portion of this lecture, talked about how the placenta has prostaglandins, and that helps keep the ductuses open. But once the umbilical cord is cut, or the placenta is no longer attached, the body isn't circulating prostaglandins. So prostaglandins, we can give a medication called prostaglandin E.
One, it is a medication that helps maintain ductal patency, so the PDA, and ensures systematic blood flow for defects that require a duct to be open, such as our hypoplastic left heart, coarctation of the aorta, tetralogy of the low, tricuspid atresia, and some of our other... congenital heart defects. So you are the nurse caring for a neonatal patient who has a ductal dependent lesion.
The provider orders prostaglandin E1 as started at 0.1 mics per kilo per minute to keep the patent ductus arteriosa arteriosa open. Your patient weighs 2.5 kilograms. What is your hourly rate of prostaglandin in mics?
So what's important to pull out from this? As you can see, the order is 0.1 micrograms per kilogram per minute. And then also your patient's weight. That's always very important in our PEDS patients.
And then we want to know the hourly rate. So how many minutes are in one hour? You have 60 minutes.
All right. So we got part of this down. We have 60 minutes. So next we're going to do our... 0.1 mics times our patient's weight, which is 2.5 kilograms.
What do we get? 0.25 mics per kilogram per minute. So this is what our dose is per minute.
So we want 0.25 mics per minute. So we have our 0.25 mics per minute, and we want to know what our hourly rate is, because that's what we're going to program into our pump. So we have 60 minutes in one hour.
So we times those together. And we get our 15 mics per hour. So this is our dose per hour.
So this is what the question is asking you. So make sure you read questions entirely to make sure you get them right. So congestive heart failure.
What is this? What is it in pediatric patients? So congestive heart failure is the inability of the heart to pump an adequate amount of blood to the systematic circulation and normal filling pressures.
to meet the body's metabolic demands. It can be referred as either congestive heart failure or just heart failure. In children, heart failure occurs secondary to structural abnormalities, which could be septal defects. The result, an increased blood flow and pressure within the heart.
It can also result from myocardial failure, in which contractility or relaxation of the ventricle is impaired. This can occur with cardiomyopathy, dysrhythmias, or severe electrolyte disturbances. Heart failure can also occur because of excessive demands on normal heart muscle, such as sepsis or severe anemia. Right-sided heart failure, the ventricle, the right ventricle is unable to pump blood effectively into the pulmonary artery, which causes an increase in pressure in the right atrium and systematic venous circulation. Left-sided heart failure, the left ventricle is unable to pump blood effectively into the systematic circulation, which causes increase in pressure in the left atrium and pulmonary veins.
What problems? to each side of these cause. They're going to be a little bit different.
So on our right side, we have venous hypertension, causes heptospina megaly, and occasionally edema. If we have left sided heart failure, lungs become congested with blood, causing elevated pulmonary pressures and pulmonary edema. So what are our signs and symptoms?
The signs and symptoms of heart failure can be divided into three groups. Impaired myocardial function, pulmonary congestion, and systematic venous congestion. Because these hemodynamic changes occur from different causes at different times, the clinical presentation may vary among children.
Diagnosis is made based on the clinical symptoms such as tachypnea, tachycardia at rest, dyspnea, retractions, activity intolerance, especially during feeding in infants, feeding intolerance, weight gain caused by fluid retention, and heptamagaly. So what do we do? What are we going to do for these patients? Our therapeutic management.
Our goals in treatment are to, first, improve that cardiac function. We've got to increase that contractility and decrease that afterload. Remove accumulated fluid and sodium.
Decrease preload and minimize fluid overload. Decrease cardiac demands. And improve tissue oxygenation and decrease oxygen.
And decrease oxygen consumption. For most infants diagnosed with heart failure, the cause is congestive. congenital heart disease. Three groups of drugs are used to enhance myocardial infunction in heart failure.
Digoxin, which improves contractility or the squeeze of the heart. Angiotension-converting enzymes or ACE inhibitors, which reduce the afterload on the heart and thus make it easier for the heart to pump, and beta blockers. Myocardial efficiency is improved through administration of Digoxin.
Digoxin is an inotrope of medication. You want to monitor your apical pulse rate. A medication is not given if the pulse rate is low.
Other common signs of DIG toxicity in children can include nausea, vomiting, anorexia, bradycardia, and dysrhythmias. This is something you want to teach your parents that are going home. This is part of your nursing education about digoxin and that.
what it does. So it helps improve the squeeze of the heart, but there's risks associated with it. One of the common things that is associated with DIG toxicity would be vomiting.
So this is something to remember because you are a nurse or will be a nurse soon. And this is something you might have to teach your patients. So DIG toxicity will include vomiting, nausea, anorexia, bradycardia, and dysrhythmias.
All right, next is going to be our acquired heart disease. diseases. I'm going to stop this presentation and then you get to go on to the next one.