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.