Chapter 13: Intestinal Failure

I. Intensive care

1. Definition

   1. Intestinal failure refers to the inability of a patient to sustain oneself via the enteral route.

   2. Often, the loss of intestinal length due to surgical resection is referred to as either short gut syndrome or short bowel syndrome, although these terms exclude forms of intestinal failure in which intestinal length is normal but may not allow for proper absorption of nutrients.

   3. Primary causes for intestinal failure in neonates include

      1. Necrotizing enterocolitis: A multifactorial inflammatory condition of the GI tract that has a large spectrum of severity and the most severe form results in full-thickness bowel necrosis.

      2. Intestinal atresia: Failure of part of the intestinal tract to completely form, causing an obstruction.

      3. Gastroschisis: Full-thickness, typically right-sided, paraum- bilical abdominal wall defect and primarily has the intestines and stomach protruding through the defect in the amniotic fluid.

      4. Omphalocele: Anterior abdominal wall defect at the base of the umbilical cord with herniation of intra-abdominal contents within sac made of the layers of the umbilical cord.

      5. Midgut volvulus: A condition in which the intestines become twisted due to malrotation during fetal development.

2. Incidence

   1. NEC is the most common cause of intestinal failure in infants and is diagnosed in roughly one to three per 1000 live births and the incidence increases to approximately 10% in infants of very low birthweight (<1500 g).

3. Pathophysiology

   1. The exact etiology of NEC is not known.

   2. Multiple processes can lead to an ischemic insult to the gastrointestinal mucosa.

   3. Prematurity and low birthweight appear to be risk factors perhaps due to immaturity of the immune system and underdevelopment of the GI mucosal barrier.

4. Risk factors

   1. In neonates, surgical resection necessitated by either congenital or acquired diseases represent the most common causes of intestinal failure, with necrotizing enterocolitis, gastroschisis, atresias, and midgut volvulus representing the most common causes of intestinal failure.

   2. However, functional disorders of motility, such as long-segment Hirschsprung disease, and enterocyte disorders, such as intestinal epithelial dysplasia, may also be encountered in this age group.

   3. Whatever the cause, the ultimate goal of treatment is to allow for normal growth while allowing for intestinal rehabilitation in the hopes that the patient will eventually be able to sustain himself/herself via the enteral route.

5. Clinical presentation

   1. The clinical signs of NEC are nonspecific and overlap with neonatal sepsis.

   2. The earliest signs include lethargy, abdominal distention, and vomiting.

   3. More advanced disease may present with gross blood in the stool, vital sign instability, abdominal wall erythema, peritonitis.

6. Diagnosis

   1. The diagnosis or NEC is often suspected when the triad of neutropenia, thrombocytopenia, and acidosis is identified.

   2. In addition, plasma C-reactive protein and stool reducing substances may aid in the diagnosis; however, there are no specific lab studies that confirm the diagnosis of NEC.

   3. Radiographic imaging with two-view abdominal radiographs will virtually always reveal generalized intestinal dilation consistent with ileus. Pneumatosis intestinalis is considered pathopneumonic, but may be only transiently evident even in severe forms. Advanced cases may demonstrate free air associated with perforation or ...