Multi-modal CT in acute stroke: wait for a serum creatinine before giving intravenous contrast? No!

Background Multi-modal CT (MMCT) to guide decision making for reperfusion treatment is increasingly used, but there remains a perceived risk of contrast-induced nephropathy (CIN). At our center, MMCT is used empirically without waiting for serum-creatinine (sCR) or renal profiling. Aims To determine the incidence of CIN, examine the risk factors predisposing to its development, and investigate its effects on clinical outcome in the acute stroke population. Methods An institution-wide protocol was implemented for acute stroke presentations to have MMCT (100-150 ml nonionic tri-iodinated contrast, perfusion CT and CT angiography) without waiting for serum-creatinine to minimize delays. Intravenous saline is routinely infused (80-125 ml/h) for at least 24-h after MMCT. Serial creatinine levels were measured at baseline, risk period, and follow-up. Renal profiles and clinical progress were reviewed up to 90 days. Results We analyzed 735 consecutive patients who had MMCT for the evaluation of acute ischemic or hemorrhagic stroke during the last five-years. A total of 623 patients met the inclusion criteria for analysis: 16 cases (2.6%) biochemically qualified as CIN; however, the risk period serum-creatinine for 15 of these cases was confounded by dehydration, urinary tract infection, or medications. None of the group had progression to chronic kidney disease or required dialysis. Conclusions The incidence of CIN is low when MMCT is used routinely to assess acute stroke patients. In this population, CIN was a biochemical phenomenon that did not have clinical manifestations, cause chronic kidney disease, require dialysis, or negatively impact on 90-day mRS outcomes. Renal profiling and waiting for a baseline serum-creatinine are an unnecessary delay to emergency reperfusion treatment.