Valette X, Desmeulles I, Savary B, et al. Crit Care Med. 2017; 45: 637-44.
Study Question: Is volume expansion with sodium bicarbonate superior to sodium chloride for preventing contrast-associated AKI (CA-AKI)?
Study Description: A multi-center, double-blind, randomized controlled trial evaluated IV volume expansion in critically ill patients (≥ 18 years) who underwent imaging with intravascular contrast and were in an ICU for one day. Excluded patients included those with unstable renal function [recent SCr increase, anuria, or requiring renal replacement therapy (RRT)] or patients with contraindications to volume expansion or bicarbonate loads. The primary endpoint was development of CA-AKI within 72 hours of contrast exposure (increase in SCr ≥ 0.3 mg/dL or 50% of baseline, or urinary output of < 0.5 mL/kg/hr for 6 hours) which corresponds with the AKIN criteria. Secondary endpoints included CA-AKI incidence according to alternative definitions, post-hydration urinary pH, need for RRT, ICU length of stay and ICU mortality. Patients received equivalent volumes of either 0.9% sodium chloride or 1.4% sodium bicarbonate dosed according to guideline recommendations.
Results: Of 1458 patients assessed, 156 were included in the saline group and 151 in the bicarbonate group. There was no difference in CA-AKI incidence between the bicarbonate and saline groups (35.1% vs. 33.3%, p = 0.81) regardless of definition. There was no difference found between the two groups in any of the secondary endpoints with the exception of the urinary pH after volume expansion, which was higher in the bicarbonate group compared with the saline group (6.7 vs. 6.2, p < 0.0001).
Conclusion(s): Sodium bicarbonate hydration did not provide additional benefit when compared with sodium chloride hydration in reducing the incidence of CA-AKI, need for RRT, ICU length or stay, or ICU mortality.
Perspective: Results from previous studies regarding volume expansion with bicarbonate or saline to prevent CA-AKI have been conflicting. This study aids in refuting the potential benefit of bicarbonate hydration in critically ill patients over saline hydration. Notably, patients at the highest risk for CA-AKI (unstable renal function) were excluded. Whether a potential benefit of sodium bicarbonate hydration may remain in this niche population warrants further investigation.