Fluid balance neutralization secured by hemodynamic monitoring versus protocolized standard of care in patients with acute circulatory failure requiring continuous renal replacement therapy: results of the GO NEUTRAL randomized controlled trial

Purpose

Net ultrafiltration (UF_NET) during continuous renal replacement therapy (CRRT) can control fluid balance (FB), but is usually 0 ml·h⁻¹ in patients with vasopressors due to the risk of hemodynamic instability associated with CRRT (HIRRT). We evaluated a UF_NET strategy adjusted by functional hemodynamics to control the FB of patients with vasopressors, compared to the standard of care.

Methods

In this randomized, controlled, open-label, parallel-group, multicenter, proof-of-concept trial, adults receiving vasopressors, CRRT since ≤ 24 h and cardiac output monitoring were randomized (ratio 1:1) to receive during 72 h a UF_NET ≥ 100 ml·h⁻¹, adjusted using a functional hemodynamic protocol (intervention), or a UF_NET ≤ 25 ml·h⁻¹ (control). The primary outcome was the cumulative FB at 72 h and was analyzed in patients alive at 72 h and in whom monitoring and CRRT were continuously provided (modified intention-to-treat population [mITT]). Secondary outcomes were analyzed in the intention-to-treat (ITT) population.

Results

Between June 2021 and April 2023, 55 patients (age 69 [interquartile range, IQR: 62; 74], 35% female, Sequential Organ Failure Assessment (SOFA) 13 [11; 15]) were randomized (25 interventions, 30 controls). In the mITT population, (21 interventions, 24 controls), the 72 h FB was −2650 [−4574; −309] ml in the intervention arm, and 1841 [821; 5327] ml in controls (difference: 4942 [95% confidence interval: 2736–6902] ml, P < 0.01). Hemodynamics, oxygenation and the number of HIRRT at 72 h, and day-90 mortality did not statistically differ between arms.

Conclusion

In patients with vasopressors, a UF_NET fluid removal strategy secured by a hemodynamic protocol allowed active fluid balance control, compared to the standard of care.