Our study is the first published multicenter and randomized
study that compares two limits for GRV in tubefed
ICU patients with mechanical ventilation. According
to the data presented, we can conclude that increasing the
limit for normal GRV to 500 ml is associated with an
increase in the diet VR of ICU patients treated with EN.
This is not associated with adverse effects in gastrointestinal
complications or in outcome variables. In
conclusion, a value of 500 ml could be recommended as a
limit for GRV in mechanically ventilated ICU patients
treated with enteral nutrition by nasogastric tube and
receiving also metoclopramide as a motility agent from
the beginning of the EN. Nevertheless, before generalizing
the clinical use of our recommendation, it is necessary
to consider some issues that could limit the generalization
of our results. These have been mainly obtained in medical
patients, by a homogeneous group of investigators
experienced in the application of EN to critically ill
patients (as can be seen in previous publications of our
working group [1, 2]) and using a ‘‘prophylactic’’ treatment
with motility agents to theoretically protect against
EN pulmonary complications. More studies are needed in
this field. Nevertheless, with these considerations, our
results suggest that feeding protocols that use a cutoff
value for GRV could consider the 500 ml limit.