Prevention of contrast-induced nephropathy with sodium bicarbonate: a randomized controlled trial.
BACKGROUND
Contrast-induced nephropathy remains a common complication of radiographic procedures. Pretreatment with sodium bicarbonate is more protective than sodium chloride in animal models of acute ischemic renal failure. Acute renal failure from both ischemia and contrast are postulated to occur from free-radical injury. However, no studies in humans or animals have evaluated the efficacy of sodium bicarbonate for prophylaxis against contrast-induced nephropathy.


OBJECTIVE
To examine the efficacy of sodium bicarbonate compared with sodium chloride for preventive hydration before and after radiographic contrast.


METHODS
A prospective, single-center, randomized trial conducted from September 16, 2002, to June 17, 2003, of 119 patients with stable serum creatinine levels of at least 1.1 mg/dL (> or =97.2 micromol/L) who were randomized to receive a 154-mEq/L infusion of either sodium chloride (n = 59) or sodium bicarbonate (n = 60) before and after iopamidol administration (370 mg iodine/mL). Serum creatinine levels were measured at baseline and 1 and 2 days after contrast.


METHODS
Patients received 154 mEq/L of either sodium chloride or sodium bicarbonate, as a bolus of 3 mL/kg per hour for 1 hour before iopamidol contrast, followed by an infusion of 1 mL/kg per hour for 6 hours after the procedure.


METHODS
Contrast-induced nephropathy, defined as an increase of 25% or more in serum creatinine within 2 days of contrast.


RESULTS
There were no significant group differences in age, sex, incidence of diabetes mellitus, ethnicity, or contrast volume. Baseline serum creatinine was slightly higher but not statistically different in patients receiving sodium bicarbonate treatment (mean [SD], 1.71 [0.42] mg/dL [151.2 [37.1] micromol/L] for sodium chloride and 1.89 [0.69] mg/dL [167.1 [61.0] micromol/L] for sodium bicarbonate; P =.09). The primary end point of contrast-induced nephropathy occurred in 8 patients (13.6%) infused with sodium chloride but in only 1 (1.7%) of those receiving sodium bicarbonate (mean difference, 11.9%; 95% confidence interval [CI], 2.6%-21.2%; P =.02). A follow-up registry of 191 consecutive patients receiving prophylactic sodium bicarbonate and meeting the same inclusion criteria as the study resulted in 3 cases of contrast-induced nephropathy (1.6%; 95% CI, 0%-3.4%).


CONCLUSIONS
Hydration with sodium bicarbonate before contrast exposure is more effective than hydration with sodium chloride for prophylaxis of contrast-induced renal failure.
Merten
Gregory J
GJ
Department of Internal Medicine, Sanger Cardiology, Sanger Cardiovascular Surgery, and Metrolina Nephrology, Carolinas Medical Center, Charlotte, NC 28232, USA.
Burgess
W Patrick
WP
Gray
Lee V
LV
Holleman
Jeremiah H
JH
Roush
Timothy S
TS
Kowalchuk
Glen J
GJ
Bersin
Robert M
RM
Van Moore
Arl
A
Simonton
Charles A
CA
Rittase
Robert A
RA
Norton
H James
HJ
Kennedy
Thomas P
TP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000009:adverse effects*; D003404:Creatinine / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007479:Iopamidol / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography; D015532:Rehydration Solutions / Q000627:therapeutic use*; D051437:Renal Insufficiency / Q000139:chemically induced* / Q000517:prevention & control*; D017693:Sodium Bicarbonate / Q000627:therapeutic use*; D012965:Sodium Chloride / Q000627:therapeutic use; D014882:Water-Electrolyte Balance
D003287:Contrast Media; D015532:Rehydration Solutions; D012965:Sodium Chloride; D017693:Sodium Bicarbonate; D003404:Creatinine; D007479:Iopamidol