Nutrition and congestion in critically ill patients: myth or reality?

Despite the benefits of proper nutrition for critically ill patients, there continues to be an insufficient degree of nutrition among patients in Intensive Care Units. Certain aspects remain underexplored, such as the potential impact of artificial nutrition on blood volume. The initiation of nutrition implies an increase in the patient’s daily fluid intake, with a heightened risk of congestion. This issue is especially relevant in critically ill cardiovascular patients, who frequently present with some degree of ventricular dysfunction, which may complicate blood volume management.

This study aims to determine if there is an increased risk of developing congestion in intubated patients in a Cardiovascular Intensive Care Unit (CV ICU) receiving artificial nutrition (either enteral or parenteral) and to understand the implications this has for patient management.

This is a retrospective observational study of patients under mechanical ventilation who received artificial nutrition between November 2021 and August 2024. Data were collected on diuretic use the day prior to nutrition initiation, the day of initiation, and the two days following initiation. Higher diuretic requirements were associated with a greater degree of congestion or increased difficulty in achieving an adequate fluid balance.

A total of 53 patients were recorded. Baseline population characteristics are shown in Table 1. The results of the analyses are shown in Image 1.

No significant differences were observed in diuretic use between patients receiving enteral nutrition and those receiving parenteral nutrition (Figure A). However, significant differences were found between the amount of diuretic used the day before nutrition initiation and on the day of initiation, as well as between the day before and the two days after initiation (p = 0.048). When analyzing the groups separately, there were no significant differences in diuretic usage between the different days in the enteral nutrition group, whereas this difference became evident in the parenteral nutrition group, specifically between the average furosemide dose on the day before nutrition initiation and the 48 hours following initiation (p = 0.05), as well as between the dose on the day of initiation and the 48 hours afterward (p = 0.025) (Figure B).