Comparison of measuring energy expenditure with indirect calorimetry and traditional methods in head injury patients

Objective To compare the difference of indirect calorimetry and traditional methods for measuring energy expenditure in head injury patients of different degrees.Methods Totally 55 patients were divided into two groups by GCS: one group with GCS≤8 and the other group with GCS≥9.Both energy expenditure value was measured by indirect calorimetry and estimated using FAO/WHO/UNU and Harris-Benedict(HB) equations.Results There was no significant difference between two groups by using traditional predictive equations(P0.05),however,there was significant difference between two groups by means of indirect calorimetry(P0.05).In the group of GCS≤8,the energy expenditure measured by the three traditional equations were significantly different compared with that measured by indirect calorimetry method(P0.05).In another group in which GCS was equal to or higher than 9,the difference of energy expenditure value was not significant between the indirect calorimetry and traditional methods(P0.05.Analysis of the correlative relationship between GCS and energy expenditure measured by indirect calorimetry showed correlation in group of GCS≤8(P=0.024,r=0.434),but no correlation in group of GCS≥9(P=0.96).Conclusion The variance of energy expenditure in head trauma patients of different degrees is great,and traditional prediction methods may lead to errors in the calculation of energy expenditure,especially in the severe brain trauma patients.We recommend indirect calorimetry measurements to be used for energy expenditure value in severe head injury patients.