Long Oral Presentation ANZTS Trauma 2024 Conference

The feasibility and acceptability of measuring energy expenditure using indirect calorimetry in self-ventilating patients following traumatic injury. (21636)

Katherine Muller 1 , Emma Ridley 1 2 , Lara Kimmel 3 4 , Christopher Groombridge 5 6 7 , Oana A Tatucu-Babet 1 2 , Mark Fitzgerald 5 6 7 8 , Kate Lambell 1
  1. Nutrition and Dietetics Department, Alfred Health, Melbourne, VIC, Australia
  2. Australian and New Zealand Intensive Care Research Centre, Monash University, Melbourne, VIC, Australia
  3. School of Public Health and Preventive Medicine, Monash University, Melbourne, VIC, Australia
  4. Allied Health Executive, Alfred Health, Melbourne, VIC, Australia
  5. National Trauma Research Institute, Melbourne, VIC, Australia
  6. School of Translational Medicine, Monash University, Melbourne, VIC, Australia
  7. Trauma Service, Alfred Health, Melbourne, VIC, Australia
  8. School of Information Technology, Faculty of Science, Engineering and Built Environment, , Deakin University , Melbourne, VIC, Australia

Background: Indirect calorimetry (IC) is the gold standard method for measuring energy expenditure (EE). Despite clinical guidelines recommending nutrition be delivered based on measured EE, quick predictive equations are most commonly used in practice, with potential for over-and under-estimation of energy needs. We aimed to assess the feasibility and acceptability of measuring EE using IC and compare measured to estimated EE in patients following traumatic injury.

Methods: In a single-centre prospective observational study, EE was measured using IC via a canopy hood in patients admitted to a trauma ward with ≥7day hospital stay. Feasibility was set at >50% of IC measurements being valid (≥5 minutes with ≤10% variation in VO2 and VCO2). Following the measurement, patients and staff completed an acceptability survey. Measured EE(kcal) was compared to estimated EE(kcal) using predictive equations (25kcal/kg, Schofield, 30kcal/kg), with ±10% difference considered clinically significant.  

Results: Of 30 IC measurements, 25(83%) were valid with all participants reporting the test was comfortable. Measurements were not completed or valid in 5(17%) participants due to discomfort, pain, and difficult bedspace (each n=1) and high CO2 variability(n=2). All staff agreed IC was acceptable to incorporate into usual care. Estimated EE was within ±10% of measured EE in 28%, 44%, and 60% of patients for 25kcal/kg, Schofield equation, and 30kcal/kg, respectively.

Conclusion: Measured EE using IC is feasible and acceptable following traumatic injury. A clinically significant difference in energy was observed between measured and estimated EE. Further research is warranted to evaluate whether IC-guided energy delivery improves patient outcomes.