The Impact of indirect calorimetry guided medical feeding protocol on clinical outcomes in mechanically ventilated critically ill patients

Abstract

The international guidelines recommend using indirect calorimetry (IC) to measure energy requirements in critically ill patients than the currently used weight-based equations. This single-centre randomised controlled trial aimed to assess the effects of IC-guided nutrition versus the standard nutrition care on clinical outcomes in critically ill patients. Sixty mechanically ventilated patients that were expected to stay in an intensive care unit (ICU) for more than three days were randomised into a group in which energy needs were determined by the IC (IC group) and a group prescribed with 25kcal/kg/day reflecting the standard care (SC group). The primary outcome was the ICU length of stay (LOS). Secondary outcomes included the change in quadriceps muscle layer thickness (QMLT, ultrasound) during the first ten days of ICU admission, hospital LOS, duration of mechanical ventilation, ICU mortality and 28-day-in hospital mortality. The mean energy requirement was similar in both groups (1216±222 vs 1304±211, p = 0.124). The IC group received 85.63% of the IC-based energy goal, whereas the SC group received 76.83% of the formula based energy goal (p = 0.002), although the mean energy intakes were similar in both groups. The protein intake goal was better met in the IC group (89.58 %) than in the SC group (77.66 %) (p = 0.007). Both groups had a median of 8.0 days ICU-LOS (p = 0.424). QMLT was decreased progressively in both IC and SC groups by 21.9% vs 25.3% from day 1 to day 10 (p < 0.001), respectively. There were no significant differences observed in the muscle mass changes and other secondary clinical outcomes between the groups. IC-guided nutrition groups received more energy and protein, with higher feeding adequacy than the standard care group. However, there was no difference in term of clinical outcome and muscle layer thickness between both groups. This study is registered with Clinicaltrials.gov, identifier no. NCT04479254.