Safety of Low Dose IV Contrast CT Scanning in Chronic Kidney Disease

The use of radio contrast medium enhances the image quality of CT scans. However, contrast CT
is avoided in patients with CKD for fear of contrast-induced nephropathy. The current
standard of care for these patients is CT without contrast. Taking advantage of fast scanning
capabilities of modern CT scanners (64-Multi-Detector CT), the current investigators have
developed a method to use low volume iso-osmolar non-ionic radio contrast medium (30 cc)
which can be used in a selected group of adult patients with mild to moderate stable CKD
(eGFR 16-60 ml/min/m^2 for at least 12 months), who require thoracic CT imaging for
diagnostic purposes. Up to 100 patients who meet the inclusion/exclusion criteria will be
randomized to standard care (no-contrast, 50 controls) or low volume contrast CT (50
intervention group). The peak increase of serum creatinine levels within 72 hours after the
CT procedure will be measured as an outcome variable for comparison between the two groups,
as well as a safety monitoring variable in the intervention group (25% increase is the upper
threshold).

Inclusion Criteria:

- Subjects with documented stable Chronic Kidney Disease (CKD) defined as a stable eGFR
16-60 ml/min/m^2 for ≥ 12 months; and

- Referred to CT scanning procedure to evaluate pulmonary embolism, pulmonary
malignancy, acute aortic syndromes, or renal artery stenosis.

Exclusion Criteria:

- CKD Stages 1, 2 and 5

- Stage 3-4 congestive heart failure (CHF)

- Irregular supraventricular tachycardia

- Allergic to iodinated Radio Contrast Medium (RCM)

- Allergic to Mucomyst

- Pregnancy

- Evidence of acute renal failure (ARF)

- Serum bicarbonate either less than 20 meq/L or greater than 35 meq/L

- Hydration with a bicarbonate solution is contraindicated or considered unsafe by the
subject's caring physicians