Inflachromene

Iodinated contrast media (ICM) improves image quality, but there is a subset of patients who can develop life-threatening allergic reactions when exposed. Recent literature has challenged the dogma that prior allergies to contrast or shellfish can predict reactions with intravenous ICM use. It remains unclear if this holds true when used in the urinary tract. This study aims to evaluate patients who are exposed to ICM in their urinary tract and assess if preoperative allergic prophylaxis (PAP) or prior allergy to ICM (a-ICM) can predict severe adverse reactions (SARs).

This is a single-institution retrospective study of patients who had a ureteroscopy (URS) or percutaneous nephrolithotomy (PCNL) in the last 22 years. Patients with a documented allergy to ICM were divided based on if they received PAP and the procedure performed. Data were obtained through the Northwestern Enterprise Data Warehouse. Postoperative ICU admission and intraoperative epinephrine use in patients with a-ICM are our primary outcome measures as a surrogate for a SAR.

There were 12,020 patients who underwent URS or PCNL with a 0.5% rate of SARs. There is no difference in SAR rate based on a-ICM status (0.4% vs 0.5% [ p = 1.00]). Logistic regression shows a similar no significant correlation between SAR and a-ICM (odds ratios [OR]: 0.47; 95% confidence interval [CI]: 0.08–1.57) as well as SAR and PAP (OR: 0.43; 95% CI: 0.15–0.99). American Society of Anesthesiologists score, female sex (OR: 2.69; 95% CI: 1.58–4.74), and length of hospitalization (OR: 1.07; 95% CI: 1.04–1.11) correlated with SAR.

After reviewing data from 22 years of patients undergoing procedures for nephrolithiasis, we found a low rate of severe adverse reactions. Developing a reaction to ICM cannot be predicted based on prior contrast allergies or routinely prevented with PAP.

The renal risks of iodinated contrast media (ICM) and the association of gadolinium-based contrast agents (GBCAs) with nephrogenic systemic fibrosis (NSF) have been recently reassessed.

International guidelines (Société francophone de néphrologie, dialyse et transplantation/Société française de radiologie [SFNDT/SFR], European Society of Urogenital Radiology [ESUR], American College of Radiology/National Kidney Foundation [ACR/NKF], Canadian Association of Radiologists [CAR] 2018–2025) were reviewed, focusing on risk stratification, preventive measures, and the use of ICM and GBCAs in patients with chronic kidney disease (CKD).

Post-contrast acute kidney injury risk is low for eGFR ≥ 30 mL/min/1.73 m². Hydration is recommended only for eGFR < 30 mL/min/1.73 m² or first-pass intra-arterial injections. Group II GBCAs are considered safe even in advanced CKD or dialysis, with a single unconfirmed NSF case reported.

Differences between guidelines reflect their timing and limited evidence. Preventive measures should focus on the highest-risk situations.

Clinical indication should guide imaging, which should not be delayed, and recent guidelines support a rational, risk-based approach to contrast media use.