Standardization of a Multidisciplinary Protocol for Bedside Indirect Calorimetry in Surgical and Critically Ill Patients: Practical Implementation and Troubleshooting

Background: Indirect calorimetry (IC) is considered the reference standard for measuring resting energy expenditure (REE) in critically ill and surgical patients. However, despite strong recommendations from the American Society for Parenteral and Enteral Nutrition (ASPEN) and the European Society for Clinical Nutrition and Metabolism (ESPEN), routine bedside implementation of IC remains limited. This study presented a standardized multidisciplinary protocol for bedside IC and a practical troubleshooting framework for implementation in surgical and intensive care settings.Methods: The protocol was developed through multidisciplinary collaboration at a tertiary academic center and refined through approximately ۳۰۰ bedside IC measurements performed in mechanically ventilated and spontaneously breathing patients using ventilator and canopy modes. Implementation framework integrated patient preparation,environmental standardization, ventilator-specific considerations, quality-control procedures, troubleshooting strategies, and interpretation of metabolic parameters, including REE and respiratory quotient (RQ).Results: The protocol outlined standardized pre-test preparation, device calibration, leak prevention strategies, validity criteria for bedside measurements, and mode-specific operational considerations for ventilator and canopy systems. Common technical challenges including circuit leaks, elevated inspired oxygen fractions, motion artifacts, and sensor instability were discussed alongside practical corrective approaches. Representative clinical cases were presented to illustrate the interpretation of metabolic findings across different clinical scenarios.Conclusion: This protocol provided a practical roadmap for integrating IC into routine bedside nutritional assessment in critically ill and surgical patients. By standardizing implementation and troubleshooting processes, the protocol may improve the feasibility, reliability, and clinical interpretation of IC in real-world practice.

کلیدواژه ها:

Indirect calorimetry ، Resting energy expenditure ، Critical care nutrition ، Intensive care unit ، Respiratory quotient