Comparison of energy expenditure measured by metabolic monitors with standart equations in critically ill patients

Objectives: Multiple equations exist for predicting resting energy expenditure, but the these equations may not estimate accurate energy requirements at critically ill patients. Although indirect calorimetric examination is gold standard, 24 hour measurement might couse some difficulties. We aimed to compare 2 , 6 and 12 hours indirect calorimetric examinations and predicted formulas against 24 hours indirect calorimetric examination at medical ICU patients. Material and Methods: 131 entubated patient who were followed in medical intesive care unit of Cukurova Univeristy Medical Faculty more were included to this study. Energy expenditure at 2nd , 6th , 12th and 24th hours measured by indirect calorimetry were recorded. The measured values at 24th hours were coımpared with others by pearson correlation and Bland-altman analysis. Energy expenditure at 2nd , 6th ,and 12th hours were compared on a percentage basis with the energy expenditure at 24th hour. The values within %80 and %110 were considered as aedquate. Harris Benedict, Owen , Mifflin St. Joir 1990 , Ireton Jones 1992, Ireton Jones 1997 , Ireto Jones Obesity , Penn-State 1998 , Penn State 2003 , Penn State 2010 , Swinamer 1990 , Brandi 1999 , Faisy 2003 and Schofield equations were used both to estimate anergy expenditure with actual and ideal body weight. Both these calculations and corrected values with 1.3 or 1.6 were compared with 24th hour energy expenditure. Coreraltion , Bland Altman analysis and adequacy ratio were investigated. Findings: Mean energy expenditure at 24th hour was 2078 ± 794 kkcal/day. There was correlation between 24th hour energy expenditure and the other hours. Bland Altman plots did not show wide agreement limits. Although all predictive equations were corerlated with indirect calorimetry, Bland Altman plot show wide agreement limits. Mifflin,Ireton Jones 1997 or Swinamer formulas corrected with 1.3 and Penn State 2003 , Penn State 2010 , Brandi , Ireton Jones 1992 or Schofield formulas without any correction were more reliable. Results: Indirect calorimetry should be used in critically ill patients to continue accurate nutrition. Nutrition therapy must be individualized in every patient. Most reliable predictive equation decided by clinicans can be used to start nutrition therapy. 24th hour values can be used in maintenance therapy in the following period.