Contrast-Induced Nephropathy Prevention With Sodium Bicarbonate - Contrast-Induced Nephropathy Prevention With Sodium Bicarbonate

Description:

The goal of the trial was to assess the efficacy of pretreatment with sodium bicarbonate compared with sodium chloride for prophylaxis against contrast-induced nephropathy in patients undergoing radiographic procedures with contrast.

Study Design

Study Design:

Patients Screened: 141
Patients Enrolled: 119
Mean Follow Up: Two days
Mean Patient Age: Mean age 68 years
Female: 25

Patient Populations:

Age ≥18 years; stable serum creatinine ≥1.1 mg/dl; and scheduled to undergo cardiac catheterization, computed tomography, diagnostic or therapeutic arteriography, or transjugular intrahepatic portal systemic shunt placement using the nonionic radiographic contrast agent iopamidol

Exclusions:

Serum creatinine ≥8 mg/dl; change in serum creatinine of ≥0.5 mg/dl during previous 24 hours; preexisting dialysis; multiple myeloma; pulmonary edema; uncontrolled hypertension; emergency catheterization; exposure to radiographic contrast within two days of the study; allergy to radiographic contrast; pregnancy; and administration of dopamine, mannitol, fenoldopam, or N-acetylcysteine during the intended time of the study

Primary Endpoints:

Contrast-induced nephropathy, defined as an increase of 25% or more in serum creatinine within two days of contrast administration

Secondary Endpoints:

Glomerular filtration rate

Drug/Procedures Used:

Patients were randomized to a 154 mEq/l infusion of either sodium chloride (n=59) or sodium bicarbonate (n=60). The randomization therapy was administered for one hour before and six hours after iopamidol administration (370 mg iodine/ml). Serum creatinine levels were measured at baseline and one and two days after contrast. The study was conducted at a single institution.

Principal Findings:

The study was discontinued early at the recommendation of the safety monitor due to the substantially higher risk of contrast nephropathy associated with sodium chloride hydration.

Cardiac catheterization was the most frequent radiocontrast procedure (82%), followed by computed tomography (8%) and other procedures (11%). Baseline characteristics were similar between the treatment groups, including contrast volume (134 ml for sodium chloride and 130 ml for sodium bicarbonate, p=0.75). The change in serum potassium did not differ by treatment group (-0.17 mEq/l vs. -0.26 mEq/l, respectively, p=0.36), nor did serum creatinine (0.04 mg/dl vs. -0.07 mg/dl, p=0.09). However, another measure of renal function, change in glomerular filtration rate, was lower in the sodium chloride arm (-0.1% vs. 8.5%, p=0.02).

The primary endpoint of the incidence of contrast-induced nephropathy was significantly lower in the sodium bicarbonate group (1.7% vs. 13.6%, p=0.02). Following study discontinuation, all subsequent patients meeting the original inclusion criteria were treated with sodium bicarbonate and enrolled in a registry. Contrast-induced nephropathy occurred in 1.6% of patients in the registry (3/191, 95% confidence interval 0%-3.4%).

Interpretation:

Among patients undergoing radiographic procedures with contrast, sodium bicarbonate was associated with a significant reduction in the incidence of contrast-induced nephropathy compared with sodium chloride. Although the study was stopped prematurely due to the higher risk of contrast nephropathy associated with sodium chloride, subsequent patients were treated with sodium bicarbonate and entered a registry, which showed similar low rates of contrast nephropathy in patients treated with sodium bicarbonate. Due to the increase in the number of diagnostic procedures requiring contrast, there has been an increase in the number of patients with contrast-induced nephropathy.

The present study is the first large-scale randomized trial of sodium bicarbonate versus sodium chloride for prophylaxis against contrast-induced nephropathy. Larger multicenter randomized trials are warranted based on the positive findings of this single-center study.

References:

Merten GJ, Burgess WP, Gray LV, et al. Prevention of contrast-induced nephropathy with sodium bicarbonate: a randomized controlled trial. JAMA 2004;291:2328-34.

Keywords: Coronary Artery Disease, Iopamidol, Tomography, X-Ray Computed, Cardiac Catheterization, Sodium Bicarbonate, Creatinine, Contrast Media, Iodine, Potassium, Sodium Chloride, Kidney Diseases, Glomerular Filtration Rate


< Back to Listings