Objective: To compare the effects of increasing the limit for gastric residual volume (GRV) in the adequacy of enteral nutrition. Frequency of gastrointestinal complications and outcome variables were secondary goals.
Design: An open, prospective, randomized study.
Setting: Twenty-eight intensive care units in Spain.
Patients: Three hundred twenty-nine intubated and mechanically ventilated adult patients with enteral nutrition (EN).
Interventions: EN was administered by nasogastric tube. A protocol for management of EN-related gastrointestinal complications was used. Patients were randomized to be included in a control (GRV = 200 ml) or in study group (GRV = 500 ml).
Measurements and results: Diet volume ratio (diet received/diet prescribed), incidence of gastrointestinal complications, ICU-acquired pneumonia, days on mechanical ventilation and ICU length of stay were the study variables. Gastrointestinal complications were higher in the control group (63.6 vs. 47.8%, P = 0.004), but the only difference was in the frequency of high GRV (42.4 vs. 26.8%, P = 0.003). The diet volume ratio was higher for the study group only during the 1st week (84.48 vs. 88.20%) (P = 0.0002). Volume ratio was similar for both groups in weeks 3 and 4. Duration of mechanical ventilation, ICU length of stay or frequency of pneumonia were similar.
Conclusions: Diet volume ratio of mechanically ventilated patients treated with enteral nutrition is not affected by increasing the limit in GRV. A limit of 500 ml is not associated with adverse effects in gastrointestinal complications or in outcome variables. A value of 500 ml can be equally recommended as a normal limit for GRV.