Mitchell Ladd, MD, PhD, on Nutrition and Surgical Outcomes in Pediatric Crohn Disease
More than 500,000 individuals in the United States experience symptoms from Crohn disease (CD), according to the NIH. Of these, approximately 38,000 are children.
Mitchell Ladd, MD, PhD, and colleagues from The Johns Hopkins Hospital sought to better understand how malnutrition might affect surgical outcomes in children undergoing major bowel surgery. The researchers evaluated rate of wound infection, respiratory complications, reoperation, and readmission within 30 days of surgery.
The overall complication rate was 13.6%. However, results showed the more malnourished a child was, the more likely they were to experience complications.
Gastroenterology Consultant caught up with Dr. Ladd, a surgery resident at The Johns Hopkins Hospital and the study's first author, to talk about the research.
Gastroenterology Consultant: What prompted you to conduct your study?
Mitchell Ladd: Most of the credit goes to the senior author Dr. Daniel Rhee. We knew that individuals with CD were often malnourished and that the ones that were chronically ill and malnourished seemed to have more complications after surgery. We also knew in the adult literature that malnutrition results in poor outcomes and made the hypothesis that this was true in children as well. To our surprise, there has not been much work directed towards looking at surgical outcomes in children based on nutrition status. Thus, we set out to see if our hypothesis was correct that pediatric patients with CD with poor nutrition had worse outcomes after surgery. An important part of our study was how we measured malnutrition, which can be difficult to assess in children compared to adults. We are fortunate to have great nutritionists as part of the children’s center and we asked them how they prefer to measure malnutrition. As surgeons, we often measure it using blood values like albumin, but our nutritionist, Courtney Haney, is the one that directed us towards the most recent ASPEN nutrition guidelines, which recommend using BMI-for-age z score. This worked great for us because we had those data available and so we could use this definition to categorize the nutritional status of the patients.
GASTRO CON: Why do you think research on malnutrition in children with CD been limited?
ML: I think the research on malnutrition in children with CD has been limited primarily in the surgical literature. There are numerous studies in the literature about how children with CD can become malnourished. However, no one has looked at how this affects surgical outcomes. I think the reason for this is that we were extrapolating the known data from the adult literature and applying it to children. Extrapolating is probably okay for older teenagers that are nearly adults, but for the younger patients with CD, this may not work as well, so we thought it was important to specifically look at malnutrition and its effects on surgical outcomes in the pediatric population.
GASTRO CON: How can a pediatric gastroenterologist approach their care management decisions when the research is so limited?
ML: Pediatric gastroenterologists can use our study to give them pause when they see patients with CD that need surgery but are clearly malnourished. While more work is needed to determine if optimizing nutrition will improve outcomes, it makes sense that improving one’s nutrition would be beneficial. Thus, I think when gastroenterologists see these types of pediatric CD patients, they should work closely with their pediatric surgeons and nutritionists to improve their nutrition and plan an elective surgery if at all possible, in order to have the best chance at a positive outcome with minimal complications.
GASTRO CON: What was the most surprising finding from your study?
ML: We were surprised by two findings. The first is that the group of children that were moderately malnourished, that is, in the middle, did not seem to have statistically worse outcomes. However, the children that were mildly malnourished or severely malnourished did. It is not clear why this is, but one theory that we have is that perhaps the moderate group represents the group of children that everyone recognizes as being malnourished and the group on which we can intervene. This means that they can be better optimized before surgery compared to the severely malnourished group who are certainly recognized as being malnourished, but perhaps are so ill we are not able to delay their surgery.
In the mildly malnourished group, our theory was that perhaps clinicians were not identifying them as being somewhat malnourished and thus while they could have been optimized, they were not and thus had worse outcomes. The truth is, we really don’t know, but it was an interesting finding on which we have spent a lot of time speculating the cause.
Another interesting finding was that when we looked at children with a normal albumin and stratified them via their BMI-for-age z score, we found the same trend – i.e. mildly malnourished seemed to do worse and severely malnourished did worse, but moderately malnourished did not have worse outcomes.
GASTRO CON: Since more research is needed, how can a doctor optimize a patient’s health before and after surgery?
ML: I think the most important thing is for pediatric gastroenterologists, pediatric surgeons, and pediatric nutritionists to work together to develop an appropriate plan for each patient. Each patient will have different nutritional needs and different severity of disease. Since there are no data to determine what nutritional state is “best” to reach before surgery, the goal of optimizing a patient’s nutrition will have to be defined by the multidisciplinary team. The goal of future research is to determine which BMI-for-age z score would be best to determine that a child is ready from a nutritional standpoint for surgery.
Reference:
Ladd MR, Garcia AV, Leeds IL, et al. Malnutrition increases the risk of 30-day complications after surgery in pediatric patients with Crohn disease. J Pediatr Surg. 2018;53(11):2336-2345. https://doi.org/10.1016/j.jpedsurg.2018.04.026.