Does zinc possess renoprotective properties in patients under cardiac surgery?

1. Ortega‐Loubon C, Fernández‐Molina M, Carrascal‐Hinojal Y, Fulquet‐Carreras E. Cardiac surgery‐associated acute kidney injury. Ann Card Anaesth 2016;19:687‐98. 2. Gaffney AM, Sladen RN. Acute kidney injury in cardiac surgery. Curr Opin Anaesthesiol 2015;28:50‐9. 3. Berger MM, Soguel L, Shenkin A, Revelly JP, Pinget C, Baines M, et al. Influence of early antioxidant supplements on clinical evolution and organ function in critically ill cardiac surgery, major trauma, and subarachnoid hemorrhage patients. Crit Care 2008;12:R101. 4. Rao K, Sethi K, Ischia J, Gibson L, Galea L, Xiao L, et al. Protective effect of zinc preconditioning against renal ischemia reperfusion injury is dose dependent. PLoS One 2017;12:e0180028. 5. Ali‐Hassan‐Sayegh S, Mirhosseini SJ, Tahernejad M, Mahdavi P, Shahidzadeh A, Karimi‐Bondarabadi AA, et al. Impact of antioxidant supplementations on cardio‐renal protection in cardiac surgery: An updated and comprehensive meta‐analysis and systematic review. Cardiovasc Ther 2016;34:360‐70. Sir, Acute kidney injury (AKI) is a serious and common postoperative complication of cardiac surgery (CS) with incidence and mortality rate. The most prominent pathologic mechanism of AKI following CS is acute tubular necrosis.[1] The inflammatory responses, the production of free radicals, and tubular oxidative stress, which are triggered by CS, play an important role in the tubular necrosis.[2] Hence, it seems that the modification of inflammatory responses and reduction of renal tubular oxidative stress become main therapeutic targets. No proven intervention has demonstrated a definitive renal protection during CS, so far. Some pharmacological agents have revealed protective benefits on renal function; however, the current evidence is controversial. Therefore, finding effective and promising interventions for preventing this complication remains a priority for future research.