Background and importance Fluid infusion represents one of the cornerstones of intensive care unit (ICU) therapies. However, ICU-acquired fluid overload (FO) because of excessive fluid administration is common and is linked to worse long-term effects. Therefore, many groups conclude that fluid stewardship is needed to reduce unnecessary fluid administration in a timely manner and improve patient outcomes. In practice, however, maintaining a neutral fluid balance in a critically ill patient remains challenging, even after daily fluid balance monitoring. Data on fluid prescription and FO occurrence in our population is lacking. Likewise, the effect of even moderate FO on a patient’s clinical state has been poorly described.

Aim and objectives In this study we quantified retrospectively the occurrence of moderate and severe FO during the first 5 days of ICU admission. In addition, we studied the effect of FO on mortality and mean SOFA (Sequential Organ Failure Assessment) score.

Material and methods Adult patients admitted to the ICU within the period 1 September 2019–18 March 2020 were included. FO was calculated as follows: [Σ daily (fluid intake (L)–total output (L))/baseline bodyweight (kg)] × 100. Cut-off values of 5% and 10% defined moderate and severe FO, respectively. Univariate analysis was performed with a Chi-square test and Student’s t-test. A multivariate regression model was used to adjust the association between FO and the outcome variables mean SOFA score and 28-day mortality for confounding factors.

Results FO occurred in 30.6% of the patients, which were mostly surgical patients. Moderate FO occurred more frequently in comparison to severe FO (27.1% vs 6.9%). In multivariate regression analysis FO was associated with a higher mean SOFA score (2.48; 95% CI 1.76 to 3.20; p≤0,001). Lastly, multivariate analysis revealed no association between FO and 28-day mortality (OR 1.19; 95% CI 0.59 to 2.41; p=0.625).

Conclusion and relevance FO occurred in 30.6% of patients during the first 5 days of ICU admission. In most patients the FO was moderate and occurred after surgery. FO was associated with a higher mean SOFA score. No association was found between FO and 28-day mortality. A pharmacist-guided fluid stewardship protocol, focused on surgical ICU patients, would be a good start to improve these patients’ outcomes.

Conflict of interest No conflict of interest