Fifty-one brain-injured patients with peak 24-hour admission Glasgow Coma Scale (GCS) scores of 4 to 10 were prospectively randomly assigned to receive total parenteral (TPN) or enteral (EN) nutrition. Patients were studied from hospital admission to 18 days postinjury. Outcome was assessed by the Glasgow Outcome Scale at 3 months, 6 months, and 1 year postinjury. The TPN group received a significantly higher cumulative mean intake of protein than the EN group (mean +/- standard error of the mean: 1.35 +/- 0.12 vs. 0.91 +/- 0.9 gm/kg/day; p = 0.004). Mean cumulative caloric balance was also significantly higher in the TPN than in the EN group (75.6% +/- 5.13% vs. 59% +/- 4.26%; p = 0.02). Nitrogen balance was significantly more negative in the EN group during the 1st week postinjury (p = 0.002). The incidence of pneumonia, urinary tract infections, septic shock, and infections was not significantly different between groups. Classic nutritional assessment parameters such as anergy screens, total lymphocyte counts, and albumin levels were not significantly different between groups. The 11 patients in the EN group who did not tolerate tube feedings for 1 week postinjury had a significantly higher incidence of septic shock (p = 0.008). The change over time in GCS scores between groups was significantly different, with the TPN group showing a mean four-point increase in GCS score compared with a three-point increase in the EN group (p = 0.02). At 3 months the TPN group had a significantly higher percentage of favorable outcomes (43.5% vs. 17.9%, respectively; p = 0.05). At 6 months, 43.5% of the TPN group had a favorable outcome while 32.1% of the EN group had a favorable outcome (p = 0.29). By 1 year, 47.8% of the TPN group and 32.1% of the EN group had a favorable outcome (p = 0.20). In conclusion, more calories and protein usually can be administered to acute brain injury patients via the TPN route than by EN feedings via nasogastric or nasoduodenal routes. Traditional parameters for nutritional assessment are not useful in studying the efficacy of nutritional support during the first 2 weeks after head injury. Neurological recovery from head injury occurs more rapidly in patients with better early nutritional support.

This prospective randomized controlled clinical trial compares the effects of early parenteral nutrition and traditional delayed enteral nutrition upon the outcome of head-injured patients. Thirty-eight head-injured patients were randomly assigned to receive total parenteral nutrition (TPN) or standard enteral nutrition (SEN). Clinical and nutritional data were collected on all patients until death or for 18 days of hospitalization. Survival and functional recovery were monitored in survivors for 1 year. Of the 38 patients, 18 were randomized to the SEN group and 20 to the TPN group. Demographically, the two groups of patients were similar on admission. There was no significant difference in the severity of head injury between the two groups as measured by the Glasgow Coma Scale (p = 0.52). The outcome for the two groups was quite different, with eight of the 18 SEN patients dying within 18 days of injury, whereas no patient in the TPN group died within this period (p less than 0.0001). The basis for the improved survival in the TPN patients appears to be improved nutrition. The TPN patients had a more positive nitrogen balance (p less than 0.06), and a higher serum albumin level and total lymphocyte count. More adequate nutritional status may have improved the patients' immunocompetence, resulting in decreased susceptibility to sepsis. The data from this study strongly support the favorable effect of early TPN on survival from head injury.

A prospective longitudinal evaluation of serum zinc concentrations was performed in 26 head-trauma patients, and 24-hour urine zinc excretion was determined in 15 of these subjects. Patients had markedly depressed admission serum zinc concentrations (mean +/- standard error of the mean: 40.2 +/- 3.2 micrograms/dl; normal values: 70 to 120 micrograms/dl), which gradually increased during the 16-day study period. All subjects demonstrated increased urinary zinc losses throughout the study period. Urinary zinc excretion was greater in patients with more severe head injuries. Indeed, patients with more severe head trauma had mean peak urinary zinc losses of greater than 7000 micrograms/day (normal less than 500 (micrograms/day). The implications of this altered zinc metabolism for protein metabolism, wound healing, and immune function, and the specific role of zinc in brain function and recovery from injury are discussed.

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Animal investigations suggest that administration of hyperosmolar total parenteral nutrition (TPN) solutions may potentiate cerebral edema following head injury. Intravenous nutrition (TPN) is often required after head injury due to intolerance to enteral feeding (EN). This study evaluates the effect of TPN on intracranial pressure (ICP) measurements in severely brain-injured patients. Ninety-six severely brain-injured patients were randomly assigned to receive TPN or EN and were studied from hospital admission until 18 days postinjury. The TPN was started within 48 hours postinjury and the EN was started when tolerated. Peak daily ICP was not significantly different on admission and over time (overall mean +/- standard error of the mean 32.01 +/- 1.62 for TPN versus 32.5 +/- 1.25 for EN). Intracranial pressure was greater than 20 mm Hg in 75% of TPN patients and 73% of EN patients. Conventional therapy failed to control elevated ICP in 36% of TPN patients and 38% of EN patients. Of these patients, subsequent barbiturate therapy failed to control ICP in 56% of TPN patients and 64% of EN patients. Serum osmolality was not significantly different between groups at admission or over the course of the study. The TPN group tended to have higher mean serum glucose levels for the first 13 days postinjury, while the EN group had a higher mean serum glucose content thereafter, but these differences were not statistically significant. This study shows that TPN can be given safely to the severely brain-injured patient without causing serum hyperosmolality or affecting ICP levels or ICP therapy.

In an attempt to improve early enteral nitrogen replacement, nitrogen status was compared in two groups of head injured patients receiving enteral regimens of 38 to 51 kcal/kg/day with different protein concentrations. Eleven control patients received 1.5 g protein/kg/day and 10 study patients received 2.2 g protein/kg/day. Daily nitrogen excretion, corrected nitrogen balance, blood urea nitrogen changes, and enteral formula tolerance were compared between groups over a 10-day period. Those receiving 2.2 g protein/kg/day had significantly higher daily and cumulative nitrogen balances despite their higher nitrogen excretion levels. Over 10 days, the study group retained 9.2 g nitrogen. By comparison, the control group sustained a cumulative loss of 31.2 g nitrogen over 10 days, despite a mean intake of 109 g protein/day. In both groups, full strength, full rate feedings were not possible until day 10 postinjury. These data indicate that once enteral formulas are tolerated high nitrogen regimens are required to achieve positive nitrogen balance in acute severe head injury patients.

In an attempt to improve early enteral nitrogen replacement, nitrogen status was compared in two groups of head injured patients receiving enteral regimens of 38 to 51 kcal/kg/day with different protein concentrations. Eleven control patients received 1.5 g protein/kg/day and 10 study patients received 2.2 g protein/kg/day. Daily nitrogen excretion, corrected nitrogen balance, blood urea nitrogen changes, and enteral formula tolerance were compared between groups over a 10-day period. Those receiving 2.2 g protein/kg/day had significantly higher daily and cumulative nitrogen balances despite their higher nitrogen excretion levels. Over 10 days, the study group retained 9.2 g nitrogen. By comparison, the control group sustained a cumulative loss of 31.2 g nitrogen over 10 days, despite a mean intake of 109 g protein/day. In both groups, full strength, full rate feedings were not possible until day 10