Determination of the Stress Factor Calculated from the Changes in the Measured Resting Energy Expenditure with Indirect Calorimetry in Patients Undergoing Pancreaticoduodenectomy

Purpose: To predict the energy expenditure using the stress factor representing the ratio of the metabolic variation between pre-operation and post-operation in a pancreaticoduodenectomy (PD). Methods: This was a prospective study conducted on 17 patients (11 males and 6 females) who underwent PD at Chonbuk National University Hospital between March 2010 and October 2011. The rest energy expenditure was measured by indirect calorimetry 1 day before and 3 days after surgery. The height, weight, and fat free mass were also measured 1 day before surgery. Results: The mean measured rest energy expenditure 1 day before PD (mREE pre ) and 3 days after PD (mREE post ) were significantly different (16.82.6 vs. 18.83.5 kcal/kg/d, P=0.0076). The stress factor, representing the ratio of the metabolic changes between pre-and post-PD, was 1.120.17. The recommended energy requirement for PD patients is estimated to be 2324 kcal/ideal body weight/d [determined from the measured preoperative rest energy expenditure (16.82.6 kcal/kg/d)activity factor (1.2 1.3)stress factor (1.12)]. Conclusion: PD patients maintained a hypermetabolic status and the applicable stress factor was 1.12.