As the Gut Churns: Feeding Challenges in the Head‐Injured Patient

Even though it was recognized by Drew et all in 1947 that rapid nutritional deterioration occurred after craniotomy, the approach toward nutrition support for the head-injured patient has been relatively slow compared with that for other critically ill populations. The reasons for this are unclear. Perhaps it is due in part to the fact that this population of patients is more likely to be adequately nourished prior to the acute neurologic event, which leads to the perception of a stable nutritional status. Attempts at enteral feeding have been hampered by the high degree of gastric feeding intolerance in the head-injured population. In addition, there were also beliefs that total parenteral nutrition (TPN), with its hyperosmolar solutions and high volumes, could be deleterious to brain-injured patients because of concerns over the possible progression of cerebral edema.2 Thus, there were few attempts at feeding, either enterally or parenterally, until the classic study by Rapp and colleagues3 demonstrated not only the safety of TPN in head-injured patients, but also improved survival compared with those patients who were fed enterally and were unable to tolerate intragastric feedings. In this issue of JPEN, Weekes and Elia relate some interesting observations about head-injured patients.4 Because of the small number of patients in this report, one must be very careful of making sweeping conclusions about this population. Although some trends are noteworthy , they require confirmation in additional trials with use of larger sample sizes. In the present study, two sets of measurements were performed. The first battery was performed on six patients between days 3 and 5 postinjury and included measurements of indirect calorimetry continuously at the bedside, body composition, urinary nitrogen excretion, gastric emptying studies by the phenol red technique, and collection of random samples of saliva during fasting and feeding to detect glucose concentration. A second set of measurements, including indirect calorim-etry and body composition, was performed on four patients between weeks 2 and 3 postinjury. Changes in energy expenditure (EE) are easily measured with the use of indirect calorimetry devices. These are now available as metabolic cart units or, more recently, as integrated hardware in ventilator systems that specifically detect moment-to-moment or day-today changes in EE. With use of an indirect calorimeter continuously for a mean of 20 hours, the data in this study suggest that in a stable, sedated, ventilated patient who complies with the ventilator , a short-term measurement will be …