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Category Archives: Persistent Pulmonary Hypertension of the Newborn

Aside

I got an interesting referral from one hospital. It is not really that difficult of a case but it is quite puzzling for the untrained ones, nevertheless interesting.

The mothers’s history is generally unremarkable. She only had some flu-like symptoms during the last trimester of the pregnancy. There was no history of hypertension nor diabetes. Mother’s prenatal visits were timely and regular as this is very much wanted pregnancy. Generally, she never had symptoms. She came to the hospital in labor. She had an ultrasound which stated that the baby is in fine condition, there was adequate fluid. About 12 hours into delivery the bag of waters ruptured. The mom recalled that she noted the fluid to be yellow-stained (normally it should be clear). There was no foul odor.

She gave birth by normal vaginal delivery. The baby was not that big, weighing only 2.6 kgs. There was no difficulty during baby’s delivery. There was no cord loop around the neck (that may have strangulated the baby). The fluid was viscid, thickly saturated with meconium (baby’s first stool). Few minutes thereafter, the baby began to have respiratory distress requiring oxygen support.

Baby had an xray of the chest revealing pneumonia. He was then started on empiric broad spectrum antibiotics. Baby was nursing well from the mother while on oxygen supplementation. There was no progression of the respiratory distress. Despite requirement for oxygen, baby remained comfortable. On the 5th day of life, baby still cant be weaned off from oxygen, breathing was still fast although comfortable. Repeat xray of the chest revealed significant clearing of the pulmonary infiltrates initially seen on the previous xray. An arterial blood gas analysis was done but it was unremarkable. So why then is the baby requiring oxygen despite the comfortable breathing, normal blood gas analysis and clearing of xray picture?

The baby was then referred to me at this time. At first I went with the line of unresolved infection so I suggested shifting of antibiotics as well as determination of c-reactive protein (an indicator of inflammation – often due to infection, that may as well be used to monitor response to treatment).

The CRP was reactive, meaning it indicated presence of an ongoing inflammation/infection, but the value was not congruent with the distress of the baby. So I tried to play along with some of the facts that the baby presented. First, baby was born throught thickly meconium stained amniotic fluid. Second, the baby’s initial xray findings highly suggested pneumonia. Third, the baby remained oxygen dependent despite ample time for antibiotics to have worked, granting this was supposed to be an isolated pneumonia. Fourth, despite improvement of x-ray picture, the baby remained, clinically, unimproved; was still dependent on oxygen support.

With these, I came to rationalize that baby might be having meconium aspiration pneumonia (MAP). (While meconium is supposed to be sterile , meaning it is free of bacteria, antibiotics was a rational modality of treatment as CRP was reactive). But on top of the MAP, I considered that baby might be experiencing as well a complication.

I then requested to obtain blood gas analysis from the right and the left arms, with emphasis on the pulmonary oxygen between the two sites.

pda1

The aorta, the main vessel that arises from the left ventricle (red vessel creating a loop on the above illustration) gives rise to three large vessels that supply the upper part of the human body. The first branch immediately divides into two, one serving as right subclavian artery (that which supplies our right arm) and right carotid artery (that branch supplying to the blood). The second main branch becomes the left carotid artery which also supply our head on the left side whereas the third main branch is the left subclavian artery which supplies our left arm.

There usually is a ductus arteriosus that exists in the fetus and closes permanently about 10 days after the baby is born. It usually arises after the right subclavian and carotid arteries, and before the left subclavian artery. Thus, by origin, the right subclavian artery is usually termed preductal while the left subclavian artery may be, most often, post-ductal. Since preductal vessels include those vessels that send blood supply to the brain, it is also then safe to assume that preductal blood picture also reflects the same blood picture that goes to the brain.

In cases of pathology when the pressure in the right side of the heart is higher than that of the left, and the ductus artery is still patent/open, the unoxygenated blood in the right side may dilute the already oxygenated blood in the left through the ductus arteriosus. In cases therefore involving increased right-sided pressure, the baby tends to be cyanotic from this explanation.

One way of determining whether there is a significant shunting from the right side to the left side via the patent ductus arteriosus is performing a 2-D echocardiography, which exactly measures the pressures between the two sides of the heart. Just compare your obtained pressure from the right side of the heart with the normal values for age and you can immediately say there is elevation of pressure, or simply put pulmonary hypertension. Another way of determination is to obtain blood gas from preductal (right arm) and post ductal (left arm, right foot, left foot) extremities. Then, compare the partial oxygen tension/pressure (pO2). A gradient between right and left of more than 20 mmHg is highly suggestive of right sided pressure, in this case, persistent pulmonary hypertension, of the newborn (also known as persistent fetal circulation).

The baby’s right arm blood pO2 was 81.7mmHg, whereas the left arm pO2 was 42.16mmHg. There was a gradient between right and left arm of 39.1mmHg, way higher than 20mmHg cut off, clearly suggesting that the baby has a pulmonary hypertension. Pulmonary hypertension usually arises when the small supposedly thin capillaries in the lungs that carry blood for oxygenation thickens. With thick pulmonary vessels, the transit of oxygen from lung alveoli to the blood vessels is rendered more difficult and hence the slow or lack of oxygenation of the blood that returns to the heart, making the baby a little bluish. And if the pulmonary hypertension is severe, this “resists” the incoming blood from the heart and is shunted directly into the aorta via the ductus arteriosus, unoxygenated, already diluting the blood that may have successfully went into the lungs for oxygenation (but not sufficiently). This can turn into vicious cycle until the baby’s demise.

In cases however of pulmonary hypertension, where the wall between the right and left atrium has a large communication known as patent foramen ovale, since at the level of atrium there is already mixing of blood between right (unoxygenated) and left (oxgenated) sides of the heart, there may not be an appreciable gradient of pO2 between preductal and postductal blood gas analyses.

Respiratory Distress?

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Aside

Image

(Image courtesy of http://www.sciencedirect.com/science/article/pii/S0022346803008698)

During my training, I was lucky to witness a case of hydrops fetalis undergo a rare form of management done in our institution.

During the prenatal course, the obstetrician noted the baby to have hydrops fetalis. Serial ultrasound established the diagnosis and at the time the baby was nearing birth, the condition persisted.

As in my previous articles, hydrops means the generalized swelling of a fetus. The skin becomes edematous and very taut, disabling a good expansion of the chest when breathing. The pleural space, where the lungs float is also filled with fluids, compressing the lungs. So once the lungs becomes occupied by air after birth, there will be difficulty of the lungs to expand. The pericardial cavity, which the heart occupies, may also be fluid filled. Abdominal cavity may also contain fluid, termed ascites. At least 2 of these 3rd spaces must be involved before diagnosis could be entertained in an individual.

On the baby’s latest ultrasound, it was noted that the right lung has pleural effusion, the left lung was spared. In order to manage the baby optimally at birth, a pre-natal conference among all parties involved in the delivery of the baby was called – the perinatologist, neonatologist, and pediatric surgeon, to discuss how the delivery process will take place. At that time that this was done, the unang yakap was still in conception so it was not employed in this particular delivery.

The perinatologist wanted to employ EXITextrauterine intrapartum treatment. This means that the treatment will happen when the baby is out of the uterus but is still within the confines of the delivery procedure (umbilical cord remains uncut).

1.The baby was delivered via emergency section. He was brought out of the uterus, the umbilical cord still connected to the placenta.

2. The pediatric surgeon inserted a needled through the right pleural space, drained fluid as much. (The purpose of doing this is to allow maximum expansion of the lungs when it gets aerated; the fluid, if not evacuated, will limit the expansion of the lungs leading to poor tidal volume, lesser oxygenation of the blood, which will aggravate the already compromised baby).

3. Umbilical cord was then cut and baby was handed to the neonatology team.

4. Neonatologist then intubated the baby.

5. Chest x-ray was done to document the level of the tip of the endotracheal tube, check how much of the fluid was drained, and check how expanded the lung after the procedure.

In short, the procedure was successful. We were able to ventilate the baby afterwards. Baby however had other pressing problems, and as expected he when through persistent pulmonary hypertension, or persistent fetal circulation. PPHN or PFC usually results from a thickening of the walls of the arterioles/capillaries that surround the lung alveoli. Because of this thickness, oxygen travels slowly from the alveolar space into the bloodstream, thus leading to lesser oxygenation of the blood. PPHN can be primary (no identifiable cause) or secondary (a result or effect of another primary disorder). In this case, if the baby, who has hydrops fetalis, also has PPHN, it would only mean than the hydrops was a chronic disorder that it has affected the development of the lung tissue and vessels. If the PPHN was primary, then the arterioles and capillaries are thick to begin with, and there’s no way to reverse this anymore. If it is secondary, it means that the arterioles or capillaries have thinned out for postnatal life but then became thicker as a response to/result of an insult/injury. Despite proper ventilation and support given to the baby, he succumbed to PPHN after several days.

EXIT…?

 

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LUCKY: Superstitions on Baby’s Birth Date

LUCKY: Superstitions on Baby’s Birth Date.

 

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LUCKY: Superstitions on Baby’s Birth Date

Why do Filipinos still believe in superstitions, despite being a largely Catholic country? In every aspect, in every field, in every occasion, there’s always superstitious beliefs. Even if people just came from worship or Sunday mass, they still go to a Chinese person for some feng shui advice. When I was young, the first one I heard was that those “palaspas” are for driving away evil spirit. Now that I am older, there are so many silly (I consider them silly) things. During new year, people resort to silly practices just to be “lucky” for the next year. They must have 12 different round fruits on the table on new year’s eve, they must put some paper bills/coins in their wallet so that they will have money all year round, they should be wearing polka dots, again to attract money and good luck. Is that Chinese in our blood, or are we just money-driven?

In medical field, even during giving birth, again superstitions abound. Many consider giving birth at a date with the number 8 LUCKY. It’s not a strange thing anymore when parents tell you they had a cesarean delivery scheduled on the 8th, 18th or 28th of the month, at exactly 8:00am. Some even go to the extreme of informing the obstetricians that the baby should come out at exactly 8:08 or 8:18 am. If not the number 8, others want to deliver during the 9th of September, 2009; 10th of October, 2010; 11th of November, 2011; and I will not be surprised to hear someone schedule their delivery date this coming 12th of December, 2012.

Cesarean delivery has it’s own risk. As far as the baby is concerned, when the mother delivers via this method, without prior labor, the baby has not been subjected to the “stress” the mother undergoes during labor. Because of this, there is no surge in epinephrine (otherwise known as adrenaline). Low levels of circulating epinephrine in the baby’s blood leads to a low oncotic pressure (important to absorb fluids from the lung alveoli into the bloodstream; remember, the baby’s lungs are filled with fluid, NOT air, inside the uterus). After delivery, because of low oncotic pressure, there is less/slow absorption rate of the fluids from the alveoli of the infants lungs into the bloodstream. The infant then breaths fast until the fluid in his lungs is completely resorbed (condition known as transient tachypnea of the newborn), usually in 6 hours, but may last until 72 hours in some patients.

Another lifelong implication of cesarean delivery to the baby is INCREASED RISK for baby to develop allergic disorder, even if both parents deny family history of it. Vagina of adult women, just like our skin, is normally populated by bacteria; the bacterial population differs from one body part to the other. During vaginal birth, the baby tends to aspirate and swallow some of those bacteria along the maternal vaginal tract. These bacteria populate the intestines of the baby leading to, but not limited to: (1) closure of the gaps between intestinal cells, thus inhibiting proteinaceous substances to permeate the intestinal wall and incite infection or allergic reaction, (2) stimulate the intestinal immune system to secrete secretory immunoglobulin A (sIgA) that acts as a first line defense against invading pathogenic/infectious bacteria/virus/fungi in the intestines, therefore protecting baby from infection – this is how our immune system act for the first time after birth.

Now, when the baby is delivered via cesarean section, this BENEFIT of vaginal delivery is abolished. Why? The mother’s abdomen is prepared with iodine, to prevent infection of the cesarean wound. Because of this, majority if not all of the bacterial flora of the mother’s abdomen has been wiped out/eliminated. As the head of the baby is delivered, there’s nothing to aspirate/swallow that will give the above benefits of vaginal birth. Now, even if baby is latched onto the mother’s chest during that skin-to-skin contact to allow baby aspirating the chest bacterial flora, the quality of bacterial flora on the mothers’ skin is different compared to that of the vaginal flora and may act differently thus as far as infant’s immune system stimulation is concerned.

Third, just a recently published study found out that cesarean delivery led to lower expression of a protein UCP2 at the neurons found at the hippocampal region. This protein fosters short-term and long-term memories. Among mice, knocking out the UCP2 gene or chemically inhibiting this protein interfered with differentiation of the neurons and circuits at the hippocampal region and impaired adult behavior related to hippocampal functions. (See http://www.dailymail.co.uk/health/article-2185597/Babies-born-naturally-higher-IQs-delivered-caesarean-section.html?ITO=socialnet-twitter-mailonline).

A woman who had this strange belief of giving birth during a “lucky date” REQUESTED for a cesarean delivery on the 10th of October, 2010, consciously knowing that her baby is premature at 36 weeks. (Not my patient though, but I took over the case during the weekend when baby was already deteriorating). Alright, so the baby was born with a very nice birthdate of 10-10-10. Lucky, yey! NOT…

Normally babies who are 36 weeks, considered near-term, have good transition from intrauterine to extrauterine life. We USUALLY do not expect complications, breathing becomes normal in most cases. However, this particular baby developed complications, his breathing wasn’t normal as expected and eventually required mechanical ventilatory support. Still, baby deteriorated, developed persistent pulmonary hypertension of the newborn, and expired within few days. So if babies who are 36 weeks normally have good transition, how come this baby did not do any good? Honestly I don’t know what went wrong too. Or maybe nature is telling us not to interfere, let nature take its toll.

Is there really a lucky number for a birth date? Do we really have to alter the expected date of delivery just to be born at a “lucky date?” Many of you reading this may just shrug your shoulders and go on… Just consider your child’s future, consider some of the disadvantage of cesarean section, especially if it is not indicated at your birth circumstances.

 

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Service or Martyrdom?

Service or Martyrdom?.

 

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Service or Martyrdom?

This is a retro-blog.

I remember one patient who was referred to me for neonatal care. It was about 4 years ago. A mother had to deliver prematurely by cesarean section because of premature rupture of membrane and uncontrolled uterine contractions.. Baby was 28 weeks gestational age. There was no more room for control of labor, and preparing the baby’s lungs for eventual delivery; the cesarean section had to be done outright. Both parents were employed at that time, so I thought there was no problem about financial resources.

Again, as for all babies being born prematurely, he needed to be administered surfactant. It was night time, banks were closed so there’s no way the father can tender cash at that time. I told him to go to another hospital, secure surfactant with my name as guarantor and sign a waiver for them to pay for the drug in 24 hours. The medicine was released to him and thus I was able to administer it immediately.

(Image courtesy of www.nhlbi.nih.gov/health/health-topics/topics/pda/)

Baby was already being weaned from the respirator, when a new problem arose, a patent ductus arteriosus. This posed a threat as it increased the volume of blood that goes to the lungs for oxygenation and predisposing to a chronic problem: bronchopulmonary dysplasia. Oral medication given via tube to treat the problem. Then another problem set in: persistent pulmonary hypertension and renal insufficiency bordering renal failure, plus signs of systemic infection showing. I did some double volume blood exchange transfusion here besides giving respective medicines.

Baby’s persistent pulmonary hypertension responded to sildenafil. After the exchange transfusion, baby started urinating. Then the murmur disappeared. However, it took a some time to wean the baby off from the respirator because of one problem: baby developed bronchopulmonary dysplasia. I had to give cocktail of medications. Finally baby was weaned off from the respirator and was extubated but still dependent on oxygen support. There were even times when after extubation and when his BPD would exacerbate, it would require some hourly aerosolization to open up his distal airways.

When baby was almost two months, he was then discharged from the hospital, free from oxygen support, feeding well, and gaining weight daily. Due to big hospital bill, they asked if it is okay for them to sign a promisory note for their payment of my professional fee. Should I say no? I never proposed any condition at all. I just called the hospital to give my approval. They also partially paid their hospital bill.

One week from discharge, they followed up at the clinic. Few days after that, the hospital declared bankruptcy and closed. Then, my fear came true. They disappeared and never came back. They never at least had the courtesy to tell me that they can’t pay my professional fee. Nada! Boom! Ba-bye! I had their number. Sometimes I ask my secretary to remind them, but then they just say they will come to no avail. Then I recall how was I attending to that baby before, I had no car then. I would wait for a cab to visit the baby. Then during early mornings, I had to walk for about 10-15 minutes going to the main road to hail a cab to go back home. And then this is what I deserve.

The perks of a neonatologist. Other colleagues surely do have their own stories and could be worse than this.

 

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