Incidence of Contrast-Induced Nephropathy after Contrast-Enhanced Computed Tomography in the Outpatient Setting

Abstract

Background and objectives: No prospective study has reported the incidence of contrast-induced nephropathy (CIN) or the associated morbidity and mortality after contrast-enhanced computed tomography (CECT) in the outpatient setting.Design, setting, participants, & measurements: We enrolled and followed a prospective, consecutive cohort (June 2007 through January 2009) of patients who received intravenous contrast for CECT in the emergency department of a large, academic, tertiary care center. Outcomes measured were as follows (1) CIN: An increase in serum creatinine >0.5 mg/dl or >25% 2 to 7 d after contrast administration; (2) severe renal failure: An increase in serum creatinine to >3.0 mg/dl or the need for dialysis at 45 d; and (3) renal failure as a contributing cause of death (consensus of three independent physicians) at 45 d.Results: The incidence of CIN was 11% (70 of 633) among the 633 patients enrolled. Fifteen (2%) patients died within 45 d, including six deaths after study-defined CIN. Seven (1%) patients developed severe renal failure, six of whom had studydefined CIN. Of the six patients with CIN and severe renal failure, four died, and adjudicators determined that renal failure significantly contributed to all four deaths. Thus, CIN was associated with an increased risk for severe renal failure and death from renal failure.Conclusions: CIN occurs in >10% of patients who undergo CECT in the outpatient setting and is associated with a significant risk for severe renal failure and death.

Are intravenous injections of contrast media really less nephrotoxic than intra-arterial injections?

“…Weighted mean value of CM dose, eGFR, g-I/eGFR ratio and CIN incidence with individual study sizes as weights were calculated. The weighted mean of the g-I/eGFR ratio was based on log transformation regarded to have contributed to the patient's death in 4 of the 6 cases [30]. Thus, the frequency of patients requiring renal replacement therapy among those developing CIN agrees well with the figures for coronary interventions [2,3].…”

“…are often excluded [20,30,[33][34][35][36]. This bias in patient selection compared with IA coronary procedures, where high-risk patients cannot be excluded from life-saving interventions, may in part contribute to the belief that IV CM injection implies a lower risk of CIN than IA administration.…”

The ten commandments of laboratory testing for emergency physicians

“…Harms and benefits in medical testing often coexist in a delicate balance, but measurable medical harms of excessive and often unnecessary test prescriptions are tangible and include malignancy due to diagnostic imaging (e.g., the attributable increase in cancer due to CT pulmonary angiography is approx. five case per 10,000 persons tested for PE, half of which are projected to be fatal) [8,9], renal injury caused by contrast media (e.g., acute renal failure and death may occur occurs in up 2% of cases) [10], along with other iatrogenic complications of treating patients with positive results (e.g., anticoagulants are associated with a 6-month bleeding risk of 2.8%) [11]. The benefits, however, are more elusive.…”

Patient Requests for Office-Based Imaging

“…When intravenous dye is used for imaging, there is a significant risk of kidney toxicity-ranging from 1% to greater than 10% depending on the population and type of imaging procedure [21,22]. There is also a small but real risk of kidney toxicity contributing to, or directly causing, mortality-ranging from 9 deaths per 100,000 for all CT scans using contrast to up to 0.6% for certain populations scanned in an emergency department [22,23].…”