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

Safety of Low Dose Intravenous Contrast 64 Multi-Detector Computed Tomography Scanning in Patients With Chronic Kidney Disease

The purpose of this study is to show that the use of low volume iso-osmolar non-ionic radio contrast medium (30 cc) in a thoracic CT Scanning procedure in a selected group of patients with chronic kidney disease (CKD) will avoid contrast induced nephropathy (CIN) in comparison to a similar group of patients with CKD who receive no contrast medium..

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).

Subjects in this arm will receive a single intravenous injection of low volume iso-osmolar non-ionic radio contrast medium, prior to undergoing 64-MDCT scanning. The use of low volume radio contrast medium constitutes the intervention. Both experimental and control groups receive a) acetylcysteine inhalation (Mucomyst) 1200 mg po BID x 48 hours starting the day prior to the CT scan; and b) isotonic Sodium Bicarbonate Solution 3ml/kg/hr iv for 1 hour prior to the CT scan and for 6 hours after the CT scan

Subjects in this arm will undergo 64-MDCT scanning without Radio Contrast Medium (RCM). Both experimental and control groups receive a) acetylcysteine inhalation (Mucomyst) 1200 mg po BID x 48 hours starting the day prior to the CT scan; and b) isotonic Sodium Bicarbonate Solution 3ml/kg/hr iv for 1 hour prior to the CT scan and for 6 hours after the CT scan

Intravenous injection of low volume (30 cc) iso-osmolar non-ionic radio contrast medium as part of the 64-MDCT Scanning procedure (intervention group only)

Mucomyst 1200 mg po BID x 48 hours starting the day prior to the CT scan (both experimental and control groups)

Isotonic Sodium Bicarbonate 3 ml/kg/hr iv for 1 hour prior to the CT scan and for 6 hours after the CT scan (both experimental and control groups)

The peak serum creatinine increase over baseline within 72 hours after intervention is the outcome variable. This variable is used for comparison between two groups, as well as for safety monitoring 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

Levey AS, Coresh J, Balk E, Kausz AT, Levin A, Steffes MW, Hogg RJ, Perrone RD, Lau J, Eknoyan G; National Kidney Foundation. National Kidney Foundation practice guidelines for chronic kidney disease: evaluation, classification, and stratification. Ann Intern Med. 2003 Jul 15;139(2):137-47. doi: 10.7326/0003-4819-139-2-200307150-00013. Erratum In: Ann Intern Med. 2003 Oct 7;139(7):605.