Effect of restrictive cumulative fluid balance on 28-day survival in invasively ventilated patients with moderate to severe ARDS due to COVID-19

Abstract

This study aimed to evaluate the effect of two restrictive cumulative fluid balance (CFB) trends on survival and on major clinical outcomes in invasively ventilated patients with moderate to severe respiratory distress syndrome (ARDS) due to SARS-CoV-2. Prospective data collection was conducted on patients in the intensive care unit (ICU) originating from a tertiary university hospital. The primary outcomes were the risk association between the CFB trend during D₀ to D₇ and 28-day survival. The secondary outcomes were ICU mortality, in-hospital mortality, the need for invasive ventilation at D₂₈, administration of vasoactive drugs at D₇, time on invasive ventilation after D₇, and length of ICU and hospital stay. 171 patients were enrolled in the study and divided according to their CFB trends during seven days of follow-up using model-based clustering [median CFB negative trend (n = 89) - 279 ml (- 664 to 203) and (n = 82) median CFB positive trend 1362 ml (619-2026)]. The group with CFB negative trend showed a higher chance of surviving 28-day in the ICU (HR: 0.62, 95% CI 0.41-0.94, p = 0.038). Moreover, this group had a reduced length of stay in the ICU, 11 (8-19) days versus 16.5 (9-29) days p = 0.004 and presented lower rates (OR = 0.22; 95% CI 0.09-0.52) of invasive ventilation after 28-days in the ICU. In patients invasively ventilated with moderate to severe ARDS due to COVID-19, the collective who showed a negative trend in the CFB after seven days of invasive ventilation had a higher chance of surviving 28 days in the ICU and lower length of stay in the ICU.