Effects of intravenous hydration in preventing post-contrast acute kidney injury in patients with eGFR < 30 mL/min/1.73 m.

Objectives: To investigate the effects of intravenous hydration in preventing post-contrast outcomes in patients with estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m undergoing intravenous administration of iodinated contrast media (ICM).

Methods: Hospitalized patients with eGFR < 30 mL/min/1.73 m and intravenous ICM exposure between 2015 and 2021 were included. Post-contrast outcomes include post-contrast acute kidney injury (PC-AKI) (defined by 2012 Kidney Disease: Improving Global Outcomes (KDIGO) or European Society of Urogenital Radiology (ESUR)), chronic dialysis at discharge, and in-hospital mortality. Confounding effects between the two groups were reduced to a minimum using propensity score-based matching and overlap weighting. Association between intravenous hydration and outcomes was analyzed using logistic regression.

Results: In total, 794 patients were included in the study, with 284 receiving intravenous hydration, and 510 not. After 1:1 propensity score matching, 210 pairs were generated. No significant differences were found in the outcomes between the intravenous hydration and no intravenous hydration groups: PC-AKI by KDIGO, 25.2% vs 24.8% (odds ratio (OR), 0.93; 95% confidence interval (CI), 0.57-1.50); PC-AKI by ESUR, 31.0% vs 25.2% (OR, 1.34; 95% CI, 0.86-2.08); chronic dialysis at discharge, 4.3% vs 3.3% (OR, 1.56; 95% CI, 0.56-4.50); in-hospital mortality, 1.9% vs 0.5% (OR, 4.08; 95% CI, 0.58-81.08). Overlap propensity score-weighted analysis also showed no significant effects of intravenous hydration on the incidences of the post-contrast outcomes.

Conclusions: Intravenous hydration was not associated with lower risks of PC-AKI, chronic dialysis at discharge, and in-hospital mortality in patients with eGFR < 30 mL/min/1.73 m undergoing intravenous administration of ICM.

Clinical Relevance Statement: This study provides new evidence in supporting that intravenous hydration is not beneficial to patients with eGFR < 30 mL/min/1.73 m before and after intravenous administration of iodinated contrast media.

Key Points: • Intravenous hydration before and after intravenous administration of ICM is not associated with lower risks in PC-AKI, chronic dialysis at discharge, and in-hospital mortality in patients with eGFR < 30 mL/min/1.73 m. • Withholding intravenous hydration may be considered in patients with eGFR < 30 mL/min/1.73 m around intravenous administration of ICM.