Personalized Versus Standard Hydration for Prevention of CI-AKI: a Randomized Trial With Bioimpedance Analysis

Iodinated contrast media are a well-recognized cause of iatrogenic acute kidney injury in patients undergoing imaging diagnostic or therapeutic procedures (contrast-induced acute kidney injury, CI-AKI).

Several protocols have been tested for the prevention of CI-AKI, including periprocedural hydration with isotonic saline or sodium bicarbonate, antioxidant compounds, use of low- or iso-osmolar contrast agents, and hemofiltration or dialysis. The results of these interventions and strategies have been often disappointing or inconclusive and intravenous volume expansion remains the only therapy of undisputed efficacy.

Bioimpedance analysis is an inexpensive, rapid, and accurate tool for evaluating a patient's hydration status, and can be performed at the bedside within minutes [Maioli, JACC 1014;63:1387-94]. In this study we defined patients with "lower fluid status" with high risk of CI-AKI (Male with resistance/height ratio > 315 Ohm/meter and Female > 380 Ohm/meter). BIVA may represent the optimal tool to monitor the adequacy of volume expansion and protective strategy delivery.

However, most hydration protocols rely on a "one size fits all" approach with a fixed volume and time of infusion without an assessment of whether adequate hydration was achieved. This practice risks either under-hydration without true amelioration of CI-AKI risk or over-hydration with risk of adverse outcomes.

Thus, on the basis of results of BIVA testing a randomized fluid infusion plan is prescribed.

Inclusion criteria

• consecutive patients admitted in Cardiology Unit for coronary or peripheral angiography with "lower fluid status" defined on the basis bio-impedance analysis (Male with resistance/height ratio > 315 Ohm/meter and Female > 380 Ohm/meter).

Exclusion criteria

• contrast medium administration within the 10 days
• end stage renal failure requiring dialysis
• refused to give informed consent