Are intravenous injections of contrast media really less nephrotoxic than intra-arterial injections?
We oppose the opinion that the intra-arterial administration of iodine-based contrast media (CM) appears to pose a greater risk of contrast medium-induced nephropathy (CIN) than intravenous administration since 1) in intra-arterial coronary procedures and most other intra-arterial angiographic examinations, CM injections are also intravenous relative to the kidneys, 2) there is a lack of comparative trials studying the risk of CIN between intra-arterial and intravenous procedures with matched risk factors and CM doses, 3) a bias selection of patients with fewer risk factors may explain the seemingly lower rate of CIN after CT in comparison with coronary interventions, 4) the rate of CIN following intra-arterial coronary procedures may also be exaggerated owing to other causes of acute kidney failure, such as haemodynamic instability and microembolisation, 5) roughly the same gram-iodine/GFR ratio (≈1:1) as a limit of relatively safe CM doses has preliminarily been found for both intravenous CT and intra-arterial coronary procedures and 6) the substantially higher injected intravenous CM dose rate during CT relative to an intra-arterial coronary procedure might actually pose a higher risk of CIN following CT.


CONCLUSIONS
• Most intra-arterial injections of contrast media are intravenous relative to the kidneys. • No evidence that intravenous CM injections should be less nephrotoxic than intra-arterial. • Considerably higher dose rates of CM are used for CT relative to intra-arterial procedures. • Higher dose rates may pose higher nephrotoxic risk for intravenous based CT studies.
Department of Diagnostic Radiology, University of Lund, Lasarettet Trelleborg, SE-231 85 Trelleborg, Sweden. ulf.nyman@skane.se
Ulf
U
Nyman
Torsten
T
Almén
Bo
B
Jacobsson
Peter
P
Aspelin
D000792:Angiography / Q000009:adverse effects*; D003287:Contrast Media / Q000008:administration & dosage / Q000009:adverse effects; D006801:Humans; D007269:Injections, Intra-Arterial; D007275:Injections, Intravenous; D007455:Iodine / Q000008:administration & dosage* / Q000009:adverse effects*; D007674:Kidney Diseases / Q000139:chemically induced* / Q000517:prevention & control*; D014057:Tomography, X-Ray Computed / Q000009:adverse effects*
D003287:Contrast Media; D007455:Iodine