ECMO patient energy requirements: A descriptive, retrospective cohort study

Area of Science:

• Critical care medicine
• Cardiopulmonary support
• Metabolic monitoring

Background:

• Indirect calorimetry (IC) is challenging in patients on extracorporeal membrane oxygenation (ECMO).
• A novel IC method was developed for ECMO patients.
• This study compares IC-derived energy expenditure (EE) with standard predictive equations.

Purpose of the Study:

• To present and validate a novel indirect calorimetry method for ECMO patients.
• To compare measured EE with predicted EE using common equations.
• To assess the impact of ECMO duration and cannulation type on EE.

Main Methods:

• IC performed using Q-NRG+ calorimeter with a CO2 sensor adapted to the ECMO oxygenator.
• ECMO-specific oxygen consumption (VO2) and carbon dioxide production (VCO2) calculated.
• Measured EE compared to 25 kcal/kg, 30 kcal/kg, and Mifflin St Jeor equations.

Main Results:

• 90 assessments in 52 ECMO patients analyzed.
• Measured EE was 1523 ± 432 kcal/day (18.9 ± 6.9 kcal/kg/day).
• Measured EE was significantly lower than all predicted values (P < 0.001), with differences ranging from 413-1099 kcal/day.

Conclusions:

• A viable indirect calorimetry method for ECMO patients is presented.
• Measured EE in ECMO patients is substantially lower than predicted.
• Implementing IC may help avoid overfeeding in this population.