Pediatric Annals

Firm Rounds 

A 1-month-old Boy with Necrotizing Enterocolitis

Robert Listernick, MD

Abstract

This 1-month-old boy was transferred for management of necrotizing enterocolitis (NEC). He was a 910-g product of a 26 and 6/7 week gestation to a 39-year-old gravida 1 para 0 woman. The pregnancy was complicated by gestational diabetes that was treated with insulin. Apgar scores were 7 at 1 minute and 9 at 5 minutes.

The child required mechanical ventilation for the first 2 weeks of life. He was started on total parenteral nutrition (TPN), which he received exclusively during the first week of life. On day 7 of life, he was started on small amounts of nasogastric feeds of breast milk. These were slowly increased. On day 21 of life, he received nasogastric feedings every 3 hours. However, the following day he was found to have abdominal distension and increased residual feedings. At that same time, he developed respiratory distress and was placed back on the ventilator.

A diagnosis of NEC was made. He was made nil per os (NPO), and a nasogastric tube was placed that was notable for a small amount of “red mucus.” There was pneumatosis on X-ray. He developed a coagulopathy for which fresh frozen plasma was given. In addition, he was treated with antibiotics and antifungals for several days for presumed sepsis until negative cultures were obtained. On the day of transfer, he was noted to have substantial amount of serous drainage from his umbilicus, approximately 100 cc/day.

On exam at the time of admission, he was an ill-appearing premature neonate. Pulse was 160, respiratory rate 50, blood pressure 55/41, weight 1.2 kg. There was bilateral periorbital edema. Lungs were clear. Cardiac exam was normal. Pulses were normal. Abdomen was not tender, and no masses were palpable. There was serous drainage from the umbilicus. No bowel sounds were present.

Pertinent laboratory testing included: CBC with white blood cell count 38,000/mm3 with 57% neutrophils and 30% band forms; platelet count 123,000/mm3.

Robert Listernick, MD, moderator: When this child was born, what would you tell the family about his prognosis?

Karna Murthy, MD, neonatologist: Most national registries suggest that survival at 27 weeks’ gestation is approximately 95%. At birth, we would counsel the family that with the use of surfactant, we would expect short-term respiratory issues and hospitalization, on the average, until the infant’s expected due date.

Dr. Listernick: What about the neurodevelopmental outcome?

Dr. Murthy: For this size and gestational age, approximately 15% of the surviving children will have at least one significant neurodevelopmental disability, including deficits in hearing, vision, or neurocognitive testing.

Dr. Listernick: What do you tell families about the possibility of the development of NEC?

Nicolas Porta, MD, neonatologist: It varies between nurseries, but I would estimate that the incidence of NEC is between 4% to 6% in the population whose birthweight is between 800 and 1,500 g. Of these, only a small percentage has serious complications of NEC.

Dr. Listernick: This infant received TPN for 1 week before enteral feedings, which were increased very slowly. Is this approach evidence-based?

Dr. Porta: The best approach to preventing NEC is to prevent prematurity. There’s strong evidence that breast milk is protective and less strong data to support the use of early “trophic” feedings. I tailor my approach to the individual neonate; if he had significant perinatal stressors, I withhold early feedings.

Daniel Robinson, MD, neonatologist: We know that one of the best things we can do is provide feedings as early as possible to promote maintenance of the intestinal mucosa. There is debate as to how fast to increase feedings or if only maintenance trophic feedings are necessary for promoting intestinal health.

Dr.…

This 1-month-old boy was transferred for management of necrotizing enterocolitis (NEC). He was a 910-g product of a 26 and 6/7 week gestation to a 39-year-old gravida 1 para 0 woman. The pregnancy was complicated by gestational diabetes that was treated with insulin. Apgar scores were 7 at 1 minute and 9 at 5 minutes.

The child required mechanical ventilation for the first 2 weeks of life. He was started on total parenteral nutrition (TPN), which he received exclusively during the first week of life. On day 7 of life, he was started on small amounts of nasogastric feeds of breast milk. These were slowly increased. On day 21 of life, he received nasogastric feedings every 3 hours. However, the following day he was found to have abdominal distension and increased residual feedings. At that same time, he developed respiratory distress and was placed back on the ventilator.

A diagnosis of NEC was made. He was made nil per os (NPO), and a nasogastric tube was placed that was notable for a small amount of “red mucus.” There was pneumatosis on X-ray. He developed a coagulopathy for which fresh frozen plasma was given. In addition, he was treated with antibiotics and antifungals for several days for presumed sepsis until negative cultures were obtained. On the day of transfer, he was noted to have substantial amount of serous drainage from his umbilicus, approximately 100 cc/day.

On exam at the time of admission, he was an ill-appearing premature neonate. Pulse was 160, respiratory rate 50, blood pressure 55/41, weight 1.2 kg. There was bilateral periorbital edema. Lungs were clear. Cardiac exam was normal. Pulses were normal. Abdomen was not tender, and no masses were palpable. There was serous drainage from the umbilicus. No bowel sounds were present.

Pertinent laboratory testing included: CBC with white blood cell count 38,000/mm3 with 57% neutrophils and 30% band forms; platelet count 123,000/mm3.

Robert Listernick, MD, moderator: When this child was born, what would you tell the family about his prognosis?

Karna Murthy, MD, neonatologist: Most national registries suggest that survival at 27 weeks’ gestation is approximately 95%. At birth, we would counsel the family that with the use of surfactant, we would expect short-term respiratory issues and hospitalization, on the average, until the infant’s expected due date.

Dr. Listernick: What about the neurodevelopmental outcome?

Dr. Murthy: For this size and gestational age, approximately 15% of the surviving children will have at least one significant neurodevelopmental disability, including deficits in hearing, vision, or neurocognitive testing.

Dr. Listernick: What do you tell families about the possibility of the development of NEC?

Nicolas Porta, MD, neonatologist: It varies between nurseries, but I would estimate that the incidence of NEC is between 4% to 6% in the population whose birthweight is between 800 and 1,500 g. Of these, only a small percentage has serious complications of NEC.

Dr. Listernick: This infant received TPN for 1 week before enteral feedings, which were increased very slowly. Is this approach evidence-based?

Dr. Porta: The best approach to preventing NEC is to prevent prematurity. There’s strong evidence that breast milk is protective and less strong data to support the use of early “trophic” feedings. I tailor my approach to the individual neonate; if he had significant perinatal stressors, I withhold early feedings.

Daniel Robinson, MD, neonatologist: We know that one of the best things we can do is provide feedings as early as possible to promote maintenance of the intestinal mucosa. There is debate as to how fast to increase feedings or if only maintenance trophic feedings are necessary for promoting intestinal health.

Dr. Listernick: I know that this is a topic worthy of hours of discussion, but what can briefly be said about the current thinking about the pathogenesis of NEC?

Robin Steinhorn, MD, neonatologist: Despite all our progress in medicine over the past 20 years, there have been few advances in the understanding of the pathogenesis of NEC. We know that abnormal bacterial colonization must play a role as there have been many clusters of NEC in nurseries over the years. Immature motility patterns may contribute to the development of NEC; undigested or unabsorbed nutrients might predispose to intestinal injury.Hypoxic-ischemic injury clearly plays a role; infants who have a patent ductus arteriosus are at increased risk. In addition, immaturity of intestinal barrier and innate immunity, which induce altered inflammatory responses, are very much part of the pathogenesis. Although this infant’s story is common, I wouldn’t have considered him at high risk for NEC.

Dr. Listernick: So what was the clinical gestalt when the infant arrived here?

Molly Ball, MD, neonatologist: We thought that he was critically ill. His abdomen was markedly distended with a great deal of drainage coming from the umbilicus. However, he was hemodynamically stable.

Tony Chin, MD, pediatric surgeon: We need to expand the differential diagnosis. This child undoubtedly had NEC and a bowel perforation. However, drainage from the umbilicus also can be urine coming from a patent urachus or ascites from a different, undiagnosed condition.

Dr. Listernick: As the primary involved surgeon, what was your gestalt when you saw the baby for the first time?

Marybeth Browne, MD, pediatric surgeon: The abdomen was distended but not discolored. The fluid draining from the umbilicus was straw-colored rather than succus, small intestinal contents. Although he had been receiving continuous infusions of vasopressors at the outside hospital, he was stable here and did not require any cardiorespiratory support.

Dr. Listernick: How do you decide whether a baby who has NEC requires an operation?

Dr. Browne: The main reason is abdominal wall discoloration, which usually indicates dead bowel. The presence of gas in the portal system seen on abdominal x-ray is a relative, but not absolute, indication for surgery. We actually observed this baby for several days before the initial surgery because he was so stable, believing that the drainage was urine. Each time we placed a Foley catheter into the bladder, the umbilical drainage markedly decreased. On the day of surgery, it was noted that when air was pushed into the Anderson tube, some air came out through the umbilicus.

Dr. Robin Steinhorn: We had actually tried to send the umbilical fluid for testing to assess whether it was urine; this was quite difficult for the lab to perform and was never conclusive one way or another.

Dr. Listernick: What did you observe in the operating room?

Dr. Browne: The entire small intestines and colon were necrotic and liquefied. It was so surprising that I asked my colleagues to inspect the bowel as well; they all agreed that it was entirely necrotic. Sometimes in the early stages of NEC, we’ll explore a baby and find segments of bowel that are necrotic, after which we’ll close the incision and return the next day to assess viability. This was not one of those occasions.

Dr. Listernick: What did you tell the family?

Dr. Browne: This is the conversation that you never want to have with a family. This baby was 1.2 kg and was on the ventilator but wasn’t truly sick. However, I told them that the entire bowel looked necrotic and, unfortunately, there was nothing that could be done. I expected the baby to die within the next 24 to 48 hours. Even though he was actually decompressing his peritoneal cavity through the umbilicus, I still expected him to die very soon thereafter.

Dr. Robin Steinhorn: I believe that it’s extremely important not make absolute statements, such as “He’s going to die soon” when you speak to a family. If the prediction doesn’t hold true, you create a situation in which mutual trust has become compromised and your ability to work with the family towards a resolution is damaged.

Dr. Listernick: It sounds as if you’re telling the family something unrealistic.

Dr. Robin Steinhorn: No. For instance, you might say that survival would be unprecedented without predicting when the child would die. There is a difference in the two ways of handling the situation.

David Steinhorn, MD, pediatric intensive care physician: We don’t want to give parents unrealistic, false hope by using unrealistic statements. On the other hand, you have set up an adversarial relationship with them if you tell them the child is going to die and the child doesn’t, which is what happened in this situation. You can create an untenable situation clinically for the health care team.There’s been significant literature in the past 10 years in the palliative care world that although hope in some circumstances may be a denial mechanism, it’s also a self-preserving mechanism, which allows the patient and family to function more effectively. Hope has to be framed in a realistic context in which saying that survival would be unprecedented leaves them with an “out” for something good to happen, even if you can’t offer them significant prospects of that occurring.

Dr. Porta: This family had actually had the experience of someone being told “you’re probably not going to survive” who went on to do quite well. They are quite spiritually based and took this as a source of hope and justification to continue to support this child, perhaps with escalating the intensity of care if necessary.

Dr. David Steinhorn: Clinicians sometimes get into a power struggle with families when they feel that they can’t convince the family that their medical judgment is correct. Ultimately, it will be the disease trajectory that proves the truth for the individual patient rather than opinions and statistics.

Elaine Morgan, MD, pediatric oncologist: There was an interesting study of oncology patients who had had multiple relapses and who were clearly not going to survive long term. They found that family hope was not dependent on physician prediction of outcome. You could say that their child was going to die and families still found sources of hope; not necessarily long-term survival but perhaps “my child is going to graduate college” or attend an upcoming family outing.It was actually very difficult to take away hope from a family by predicting outcomes. I think it’s important to be realistic in your predictions by looking at the trajectory of illness.

Dr. Robin Steinhorn: I agree. What’s particularly pertinent to this case is that you have parents who continue to hope for an outcome that we medically did not feel was possible. Some of the physicians involved felt that others were not fairly portraying expectations. We had a situation in which we thought we had done the best possible job, including involving the palliative care team from the onset by telling this family our frank expectations. Yet we had a family who responded by saying we would like to continue; we are going to pray for a miracle.

Dr. Listernick: So, 6 weeks later, the child is still alive. Throughout this time, he’s been stable and not requiring any ventilatory support. He’s receiving TPN without any enteral feeding. Can we see the most recent barium study of the small intestines?

Bryan Mitchell, MD, pediatric radiologist: Starting in the duodenum, there are multiple small intestinal fistulas. In addition, the transit time from stomach to rectum was the fastest I’ve ever seen.

Dr. Listernick: At this point, is he now a candidate for a small intestinal transplant?

Valeria Cohran, MD, pediatric gastroenterologist: First, he has significant cholestasis related to TPN. Low birth-weight infants are at very high risk to develop cholestasis. That doesn’t necessarily mean that they will develop end-stage liver disease; it just would be preferable if he tolerated TPN better. I have concerns that he probably would require combined liver and small intestinal transplants. Such children who are younger than 1 year have almost 50% mortality on the waiting list.

Dr. Listernick: What did you tell the family?

Dr. Cohran: I haven’t met them yet. I would honestly tell them that the smallest combined liver-bowel transplant with whom I’ve been involved weighed 5 kg, so he has a long way to go.Typically, for a combined liver-bowel transplant, you need a donor who’s approximately two-thirds the size of the recipient; infants this size who die with healthy livers are uncommon. His liver disease may worsen to the point where transplant is precluded. I can promise them I will do what I can to help him reach our goals, but I can’t promise that he will ultimately receive a small bowel transplant.

Dr. Listernick: If he does receive the combined transplant, what kind of prognosis would you give?

Dr. Cohran: Depending on the series, 5-year survival for successful liver–bowel transplant is between 40% to 75%.

Dr. Listernick: What now?

Dr. Porta: The key is to focus on the baby, making sure that whatever we do, we make the baby’s life as good as possible. We have to approach aggressive medical treatments based on the realities of what is going to be successful and what isn’t going to be successful, success being measured for the short and long terms. We must make sure that the baby is comfortable and that the family feels supported. We must work towards having as good as possible relationship with the family so that, if circumstances change, we’re poised to support them through a meaningful decision-making process.

Dr. David Steinhorn: I’ll add that just as the bioethics team doesn’t make decisions on behalf of the patient or family or medical team, the palliative care team enters as a third party in the whole relationship. The most effective way to do this is to be viewed as an ally by the family and as a resource by the medical team.

Dr. Listernick: Time will tell. Thank you, everyone.

Panelists

Robert Listernick, MD, professor of pediatrics; director of Diagnostic and Consultation Service.

Robert Listernick, MD, professor of pediatrics; director of Diagnostic and Consultation Service.

Molly Ball, MD, neonatologist.

Molly Ball, MD, neonatologist.

Marybeth Browne, MD, pediatric surgeon.

Marybeth Browne, MD, pediatric surgeon.

Valeria Cohran, MD, pediatric gastroenterologist.

Valeria Cohran, MD, pediatric gastroenterologist.

Elaine Morgan, MD, pediatric oncologist.

Elaine Morgan, MD, pediatric oncologist.

Karna Murthy, MD, neonatologist.

Karna Murthy, MD, neonatologist.

Nicolas Porta, MD, neonatologist.

Nicolas Porta, MD, neonatologist.

Daniel Robinson, MD, neonatologist.

Daniel Robinson, MD, neonatologist.

David Steinhorn, MD, pediatric intensive care physician.

David Steinhorn, MD, pediatric intensive care physician.

Robin Steinhorn, MD, neonatologist.

Robin Steinhorn, MD, neonatologist.

Key Learning Points

  1. Most national registries suggest that survival at 27 weeks gestation is approximately 95%.

  2. The best approach to preventing necrotizing enterocolitis (NEC) is to prevent prematurity. There’s strong evidence that breast milk is protective and less strong data to support the use of early “trophic” feedings.

  3. Abnormal bacterial colonization, immature motility pattern, hypoxicischemic injury and immaturity of intestinal barriers and innate immunity which induce altered inflammatory responses all are implicated in the pathogenesis of NEC.

  4. Five-year survival for successful liver- bowel transplant is between 40% and 75%.

10.3928/00904481-20110217-03

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