Effects of intravenous hydration in preventing post-contrast acute kidney injury in patients with eGFR < 30 mL/min/1.73 m${}^2$

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${}^2$ undergoing intravenous administration of iodinated contrast media (ICM). Hospitalized patients with eGFR < 30 mL/min/1.73 m${}^2$ 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. 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. 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${}^2$ undergoing intravenous administration of ICM. This study provides new evidence in supporting that intravenous hydration is not beneficial to patients with eGFR < 30 mL/min/1.73 m${}^2$ before and after intravenous administration of iodinated contrast media.