Comparison of Energy Expenditure in Mechanically Ventilated Septic Shock Patients in Acute and Recovery Periods via Indirect Calorimetry

Abstract

Background Nutrition in intensive care units (ICUs) affects morbidity and mortality. We aimed to evaluate the energy expenditure of mechanically ventilated patients in early and late septic shock periods. Methods This study retrospectively evaluated 28 mechanically ventilated septic shock patients (11 female/17 male) in a medical ICU. Indirect calorimetry (IC) measurement was performed for 24 hours during the acute and recovery periods of septic shock. The energy values calculated by Harris-Benedict equation (predicted resting energy expenditure [PREE]), measured by IC (measured resting energy expenditure [MREE]), and given to each patient were obtained in the acute and recovery periods. Results The mean age was 67.46 +/- 14.92 (36-91) years. The MREE was 2741.1 +/- 706.3 kcal/d (38.61 +/- 11.44 kcal/kg/d) and 2332.8 +/- 426.6 kcal/d (32.65 +/- 7.8 kcal/kg/d) in the acute and recovery periods, respectively, and showed significant differences (P = 0.001). The patients' energy intake was 1152.7 +/- 207.1 kcal/d and 1542.7 +/- 433.3 kcal/d in the acute and recovery periods, respectively. A significant difference existed between energy intake and MREE during the acute and recovery periods (P < 0.001 for both). Conclusion Our findings showed that energy expenditure increases in septic shock. Significant differences existed between MREE, PREE, and energy intake, which were not correlated. The MREE was higher in the acute period. Despite the increasing energy requirement, the PREE and energy intake were well below MREE. For better clinical outcomes, each patient's energy expenditure must be closely monitored and evaluated using intermittent IC measurements.