The Compass Trial.

Contrast induced nephropathy (CIN), an acute decline in renal function, may occur following intravenous iodinated contrast media-enhanced CT. In the majority of patients, CIN is a reversible condition with full recovery of renal function within two months. The CBO guideline recommends preventive hydration in patients at high risk for the development of CIN (high risk defined as estimated kidney function (eGFR) <45 mL / min OR eGFR 45-60 ml / min in combination with comorbidities also at risk of CIN). The standard preventive treatment recommeded by the CBO guideline consists of intravenous hydration with 1000 ml 0.9% of saline infused within 3-12 hours prior to and after contrast administration is. The implementation of the CBO guideline in clinical practice is expensive due to the hospitalisation that is needed for preventive hydration (yearly cost in the Netherlands : 25.9-39.0 million).
Previously, a randomized trial was conducted which showed that one-hour prehydration with sodium bicarbonate is non-inferior to pre-and posthydration with saline in patients with chronic kidney disease undergoing intravenous contrast media-enhanced CT. The use of sodium bicarbonate pre-hydration stronlgy reduced health care costs (by 66%) associated with preventive hydration, as it does not require hospitalisation but could place in daycare or even an outpatient setting.



The risk of CIN or irreversible kidney damage is very limited, especially in the group of patients with moderate renal impairment (estimated renal clearance 30-60 ml / min). However, this patient group forms the majority of patients with an indication for CIN preventive hydration. A recently published meta-analysis showed renal function to be reduced at two months post CT in only 1.1% of patients, and 0.06% of patients undergoing CT had a (temporarily) need for dialysis. Other studies showed a risk of CIN of 0-2% in patients with moderate renal impairment when preventive hydration is applied. Therefore, preventive hydration might not even be necessary in patients with moderate renal impairment. Reducting eGFR cut-off levels for preventive hydration to an eGFR <30 ml /min could result in about 70% extra savings in healthcare costs for preventive hydration.



Objective of the study:

To study whether the existing eGFR cut-off levels for preventive hydration of < 45 ml/min or between 45-60 ml/min in combination of other comorbidity at risk of CIN can be safely lowered to an eGFR < 30 ml/min, regarsless of the presence of other risk factors for the development of CIN.



Study design:

Open label, non-inferiority randomized trial.

CI-AKI preventive hydration is not needed in patients with a creatinine clearence between 30-60 ml/min undergoing intravenous contrast media-enhanced CT.

Baseline, 2-4 days, 7-14 days, and 2 months post CT.

Randomisation in a 1:1 ratio to:

1. 1 hour prehydration with 250 ml 1.4% sodium bicarbonate;

2. No preventive hydration.