T. Checkley3, H. Nyanteh2 2Omega Research Group, Orlando, FL, USA 3Nova Southeastern Univeristy, Dr. Kiran C Patel College Of Allopathic Medicine, Davie, Florida, FL, USA
Introduction: Contrast induced nephropathy (CIN) is one of the top three causes of iatrogenic kidney injury. Management of CIN consists solely of supportive care, such as hydration, and often results in prolonged hospitalization and medical monitoring. N-acetylcysteine (NAC) has been studied for its role in preventing CIN in patients exposed to contrast media, however its efficacy remains controversial. Although previously used as a mucolytic, its properties as an anti-inflammatory and antioxidant, and ability to improve endothelial dysfunction makes NAC an ideal agent to be used for the prevention of CIN. The purpose of this meta-analysis is to evaluate the effectiveness of NAC in reducing the incidence of CIN in adults undergoing contrast-enhanced procedures.
Methods: Randomized controlled trials (RCTs) investigating the protective effect of NAC against CIN in adults were searched from the databases, Cochrane Library, PubMed (MEDLINE), and Embase, yielding 760 studies. Studies evaluating NAC in isolation from other preventative measures and those measuring serum creatinine before and after contrast administration were included. CIN was defined as a 25% increase in serum creatinine level from baseline or a 0.5 mg/dL increase in serum creatinine value within 48-72 hours after intravenous contrast administration. Data was analyzed using Review Manager 5.4.1 software. Odds ratios (ORs) were estimated using Mantel-Haenszel statistical method and random-effects model with corresponding 95% confidence interval.
Results: The compiled data analysis from twenty-one RCTs, involving 4,871 participants, shows a reduction in the incidence of CIN among patients receiving NAC compared to those receiving a placebo (OR = 0.65; 95% CI, 0.52-0.83; p = 0.0004). In the seven studies that utilized i.v. NAC, incidence of CIN was reduced compared to the 14 studies using oral NAC (OR = 0.57; 95% CI, 0.41-0.78; p = 0.0004 i.v., OR = 0.76; 95% CI, 0.54 – 1.05; p = 0.09 orally). NAC showed little protective effect in diabetic and renally impaired patients and had similar effects in patients undergoing varying procedure types .
Conclusion: The results of this study illustrate NAC’s significant role in the prevention of CIN, suggesting it may be a successful prophylactic treatment in practice. The increased benefit of i.v. administration, over oral, is also supported by reduced incidence of CIN in the i.v. subgroup. Further investigation is necessary to evaluate the efficacy of NAC in patients with risk factors impacting renal function, such as diabetes and prior renal impairment. Such research may involve increasing the dosage of NAC or using NAC in combination with other protective measures to increase its protective effects.