Revised Swedish guidelines on intravenous iodine contrast medium-induced acute kidney injury 2022: A summary

Abstract

The Swedish Society of Uroradiology has revised their computed tomography (CT) guidelines regarding iodine contrast media-induced acute kidney injury (CI-AKI). They are more cautious compared to the European Society of Urogenital Radiology and the American College of Radiology since the actual risk of CI-AKI remains uncertain in patients with moderate to severe kidney damage due to a lack of prospective controlled studies and mainly based on retrospective propensity score-matched studies with low-grade evidence. Another source of uncertainty is the imprecision of glomerular filtration rate (GFR) estimating equations. However, randomized hydration studies indictae an upper limit risk of CI-AKI of about 5% for outpatients with a GFR in the range of 30–44 or 45–59 mL/min/1.73m2 combined with multiple risk factors. Apart from GFR limits, the guideline also includes limits for systemic contrast medium exposure expressed in gram-iodine/GFR ratio.

Absolute and relative GFR and contrast medium dose/GFR ratio: cornerstones when predicting the risk of acute kidney injury

“…Based on these studies and the fact that intravenous CM injections at CT imply an indirect (second pass) renal exposure similar to that from PCA/PCI, the Contrast Media Committee of the Swedish Society of Uroradiology recommends keeping the g-I/GFR ABS ratio < 1.0 also at CT [ 5 ]. In patients at risk of CI-AKI (Table 4 ) [ 59 ] the committee recommends aiming at a ratio < 0.5 at CT by reducing the CM dose according to the 10-to-10 rule [ 60 ]. This can be achieved by applying a low kilovoltage technique combined with tube loading compensation to prevent an increase in image noise [ 61 – 67 ].…”