[Analysis of energy balance and risk factors on clinical outcomes in patients with severe traumatic brain injury].

Objective: To observe the energy expenditure in severe traumatic brain injury patients, and to assess the impact of cumulative energy balance on clinical outcomes.

Methods: Using prospective self-controlled study, the change in energy expenditure of 42 patients with severe traumatic brain injury was measured by indirect calorimetry (IC). Daily energy intake was recorded. Afterwards, energy balance was calculated. The levels of nutritional biochemical indicators were compared. Logistic regression analysis was used to analyze the correlation of cumulative energy balance with clinical outcomes.

Results: Mean practical energy intake of all patients was (6787 ± 1848) kJ/d, and mean negative energy balance was (913 ± 285) kJ/d. The negative energy balance was most crucial in first 3 days after admission. Meanwhile, practical energy intake was significantly lower than target energy intake (kJ: 2859 ± 1370 vs. 6027 ± 899, P < 0.01). The practical energy intake was increased with time, and it was found that the first 14 days were crucial for development of negative energy balance. On 7th day after admission, albumin (g/L) level in plasma was lowest compared with that on 3rd day (29.5 ± 5.0 vs. 35.9 ± 3.8, P < 0.01), and then it was increased gradually returning to normal level on 28 days (34.1 ± 2.8). Three days after admission, prealbumin (mg/L: 122.5 ± 23.3) was obviously lower than normal level, but it rapidly elevated on 7th day (214.3 ± 38.6, P < 0.01) and continued to rise till 28th day (257.7 ± 25.2). On the 3rd day after admission, C-reactive protein (mg/L: 139.5 ± 54.4) was obviously higher than normal level. However, it significantly fell on 7th day (108.4 ± 42.2, P < 0.01), and it continued to fall. Logistic regression analysis showed a strong association of cumulative negative energy balance with infection and upper gastrointestinal bleeding [odds ratio (OR) of infection was 2.130, 95% confidence interval (95%CI) 1.540 to 29.661, P = 0.023; OR of upper gastrointestinal bleeding was 0.083, 95%CI 0.013 to 0.542, P = 0.009].

Conclusions: Cumulative negative energy balance may be correlated with the occurrence of complications in patients with severe traumatic brain injury. On the basis of the measurements of changes in energy by IC, early supply of sufficient energy may improve the outcome of patients.