Efficacy and safety of N-acetylcysteine for preventing post-intravenous contrast acute kidney injury in patients with kidney impairment: a systematic review and meta-analysis

Abstract

Objectives: N-Acetylcysteine (NAC) may confer protection against post-contrast acute kidney injury (PC-AKI), although evidence is sparse and conflicting. The objective was to analyse the evidence on the efficacy and safety of NAC vs no administration of NAC in preventing PC-AKI in patients with pre-existing kidney impairment undergoing a non-interventional radiological examination requiring intravenous (IV) contrast media (CM) administration.

Methods: We carried out a systematic review including randomised controlled trials (RCTs) published in MEDLINE, EMBASE, and Clinicaltrials.gov up to May 2022. The primary outcome was PC-AKI. Secondary outcomes included the requirement of renal replacement therapy, all-cause mortality, serious adverse events, and length of hospital stay. We conducted the meta-analyses using the Mantel-Haenszel method and following a random-effects model.

Results: NAC was not associated with a significant reduction in PC-AKI (RR 0.47, 95%CI 0.20 to 1.11; 8 studies; 545 participants; I²: 56%; low certainty), all-cause mortality (RR 0.67, 95%CI 0.29 to 1.54; 2 studies; 129 participants; very low certainty), or length of hospital stay (mean difference 9.2 days, 95%CI - 20.08 to 38.48; 1 study; 42 participants; very low certainty). The impact on other outcomes could not be determined.

Conclusions: NAC may not reduce the risk of PC-AKI or all-cause mortality in people with kidney impairment who receive an IV CM prior to radiological imaging, although the certainty of the evidence is very low or low.

Clinical relevance statement: Our review concludes that prophylactic administration of N-acetylcysteine may not significantly reduce the risk of acute kidney injury in patients with kidney impairment receiving an intravenous contrast media prior to non-interventional radiological imaging, which may support decision making in this common clinical scenario.

Key points: • N-Acetylcysteine may not significantly reduce the risk of acute kidney injury in patients with kidney impairment receiving an intravenous contrast media prior to non-interventional radiological imaging. • All-cause mortality and length of hospital stay would not be decreased with the administration of N-Acetylcysteine in this setting.

Keywords: Acetylcysteine; Acute kidney injury; Contrast media; Radiology; Systematic review.