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

ABSTRACT

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 (mREEpre) and 3 days after PD (mREEpost) were significantly different (16.8±2.6 vs. 18.8±3.5 kcal/kg/d, P=0.0076). The stress factor, representing the ratio of the metabolic changes between pre- and post-PD, was 1.12±0.17. The recommended energy requirement for PD patients is estimated to be 23∼24 kcal/ideal body weight/d [determined from the measured preoperative rest energy expenditure (16.8±2.6 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.