NIV 2014

Introduction: Hydration to prevent contrast induced-acute kidney injury (CI-AKI) results in a diagnostic delay when performing CT-pulmonary angiography (CTPA) in patients presenting with clinically suspected acute pulmonary embolism (PE). The aim of our study was to analyze whether withholding hydration is non-inferior to one hour 250ml 1.4% sodium bicarbonate (Na-bic) hydration prior to intravenous contrast administration for CTPA in patients with a GFR<60 ml/min.

Methods: Primary outcome of this randomized trial was the increase in serum creatinine 48-96 hours post CT. Secondary outcomes were the incidence of CI-AKI (increase in serum creatinine >25%/>0.5mg/dl), recovery of renal function, and the need for dialysis. Withholding hydration was considered non-inferior if the mean relative serum creatinine increase was at most 15% higher compared with Na-bic.

Results: From 2009-2013, 135 patients with clinically suspected PE undergoing CTPA (mean age 70.4 years range 69, mean GFR 41.9 range 51) were randomized. Mean relative serum creatinine increase for no hydration was -3.3%(SD20.5) and -3.0%(SD17.2) for Na-bic (mean difference -0.4%, 95%CI-7.0 to 6.3, P non-inferiority< 0.001). CI-AKI occurred in 9(7.0%) patients; 4(6.5%) did not receive hydration, 5(7.5%) were treated with Na-bic (p=0.82). Two patients with CI-AKI in the no hydration arm died of causes other than renal failure and one CI-AKI patient in the Na-bic arm started pre-planned dialysis within two months post CTPA. Renal function recovered in all other CI-AKI patients within two months.

Conclusion: Withholding hydration was non-inferior to Na-bic hydration prior to CT-PA, with a similar risk of CI-AKI in both groups. Therefore, our study results demonstrate that preventive hydration can be safely withheld in daily practice of chronic kidney disease patients undergoing acute CTPA for symptomatic PE.