A randomized trial to increase the efficiency of the prevention of contrast induced acute kidney injury.
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.

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.

Open label, multi-center, non-inferiority, randomized trial

Randomisation in a 1:1 ratio to:
- 1 hour prehydration with 250 ml 1.4% sodium bicarbonate
- No preventive hydration

The extent and nature of the burden for patients participating to the Compass
Study is very limited. In current daily practice, serum creatinine is measured
prior to CT. During the Compass Study, serum creatinine measurement will be
accompanied by the drawing of one extra serum sample.Furthermore, serum and
urine samples will be taken 4-6 hours and 3 and 7-10 days post CT. Serum
samples will be collected via the i.v. needle, if possible, which reduces the
amount of venipunctures. Moreover, patients will be asked for a urine sample
prior to and after CT-scan

The CBO-guideline advises to measure renal function 3 days post CT in patients
with chronic kidney disease. Therefore, the venapuncture at 3 days post CT is
not of extra burden for the patients. Furthermore, renal function will be
measured 2 months post CT in patients who have had developed CIN to analyse
whether renal function has recovered.

Particapation to the Compass Trial will result in one extra visit to the
hospital for most patients and a maximum of two extra visits for patients
developing CIN. However, the patient probably has advantages of this strick
controll of renal function.