Clinical question: What strategies are effective in reducing contrast-induced nephropathy?
Bottom line: N-acetylcysteine plus intravenous fluids alone or in combination with a statin can prevent contrast-induced nephropathy (CIN). However, the strength of the evidence for these interventions is low. (LOE = 1b)
Reference: Subramaniam RM, Suarez-Cuervo C, Wilson RF, et al. Effectiveness of prevention strategies for contrast-induced nephropathy. Ann Intern Med 2016;164(6):406-416.
Study design: Systematic review
Funding source: Government
Setting: Inpatient (ward only)
CIN is defined as an increase in serum creatinine of more than 25% or 0.5 mg/dL (44.2 umol/L) within 3 days of intravenous contrast administration. These investigators searched MEDLINE, EMBASE, and the Cochrane Library along with reference lists of relevant articles to find studies that evaluated use of N-acetylcysteine, sodium bicarbonate, sodium chloride, statins, or ascorbic acid to prevent CIN.
Two reviewers independently screened articles for eligibility, assessed each study's risk of bias, and graded the strength of evidence (SOE) for different comparisons. A total of 86 randomized controlled trials examining different strategies for CIN prevention were included. Ultimately, only 3 strategies were shown to have both a clinically important and statistically significant benefit: (1) low-dose N-acetylcysteine plus intravenous (IV) saline versus IV saline alone (pooled relative risk [RR] 0.75; 95% CI 0.63-0.89; low SOE), (2) N-acetylcysteine plus IV saline versus IV saline alone in patients receiving low-osmolar contrast media (pooled RR 0.69; 0.58-0.84; moderate SOE), and (3) statin plus N-acetylcysteine versus N-acetylcysteine alone (pooled RR 0.52; 0.29-0.93; low SOE). There were no statistically significant benefits seen with sodium bicarbonate or ascorbic acid.
Dr. Kulkarni is an assistant professor of hospital medicine at Northwestern University in Chicago.