Evidence and Patient Safety Prevail Over Myth and Dogma: Consensus Guidelines on the Use of Intravenous Contrast Media

Renal outcomes following intravenous contrast administration in patients with acute kidney injury: a multi-site retrospective propensity-adjusted analysis

PURPOSE

Evidence of an association between intravenous contrast media (CM) and persistent renal dysfunction is lacking for patients with pre-existing acute kidney injury (AKI). This study was designed to determine the association between intravenous CM administration and persistent AKI in patients with pre-existing AKI.

METHODS

A retrospective propensity-weighted and entropy-balanced observational cohort analysis of consecutive hospitalized patients ≥ 18 years old meeting Kidney Disease Improving Global Outcomes (KDIGO) creatinine-based criteria for AKI at time of arrival to one of three emergency departments between 7/1/2017 and 6/30/2021 who did or did not receive intravenous CM. Outcomes included persistent AKI at hospital discharge and initiation of dialysis within 180 days of index encounter.

RESULTS

Our analysis included 14,449 patient encounters, with 12.8% admitted to the intensive care unit (ICU). CM was administered in 18.4% of all encounters. AKI resolved prior to hospital discharge for 69.1%. No association between intravenous CM administration and persistent AKI was observed after unadjusted multivariable logistic regression modeling (OR 1; 95% CI 0.89-1.11), propensity weighting (OR 0.93; 95% CI 0.83-1.05), and entropy balancing (OR 0.94; 95% CI 0.83-1.05). Sub-group analysis in those admitted to the ICU yielded similar results. Initiation of dialysis within 180 days was observed in 5.4% of the cohort. An association between CM administration and increased risk of dialysis within 180 days was not observed.

CONCLUSION

Among patients with pre-existing AKI, contrast administration was not associated with either persistent AKI at hospital discharge or initiation of dialysis within 180 days. Current consensus recommendations for use of intravenous CM in patients with stable renal disease may also be applied to patients with pre-existing AKI.

Intravenous CT Contrast Media and Acute Kidney Injury: A Multicenter Emergency Department-based Study

Background Although the historical risk of acute kidney injury (AKI) after intravenous administration of contrast media might be overstated, the risk in patients with impaired kidney function remains a concern. Purpose To investigate whether intravenous contrast media administration during CT is associated with a higher risk of AKI and further hemodialysis compared with the risk in patients undergoing unenhanced CT. Materials and Methods This retrospective study evaluated patients who underwent contrast-enhanced or unenhanced CT in five Taiwanese emergency departments between 2009 and 2016. The outcomes were AKI within 48-72 hours after CT, AKI within 48 hours to 1 week after CT, or further hemodialysis within 1 month after CT. The associations between contrast media exposure and outcome were estimated by using an overlap propensity score weighted generalized regression model. Subgroup analyses were performed according to the estimated glomerular filtration rate (eGFR). Results The study included 68 687 patients (median age, 68 years; interquartile range, 53-74 years; 39 995 men) with (n = 31 103) or without (n = 37 584) exposure to contrast media. After propensity score weighting, contrast media exposure was associated with higher risk of AKI within 48-72 hours after CT (odds ratio [OR], 1.16; 95% CI: 1.04, 1.29; P = .007) but no significant risk at 48 hours to 1 week after CT (OR, 1.00; 95% CI: 0.93, 1.08; P = .90). Among patients with eGFR less than 30 mL/min/1.73 m², exposure to contrast media was associated with a higher AKI risk (48-72 hours after CT: OR, 1.36; 95% CI: 1.09, 1.70; P = .007) (48 hours-1 week after CT: OR, 1.49; 95% CI: 1.27, 1.74; P < .001) and a higher risk of hemodialysis (OR, 1.36; 95% CI: 1.09, 1.70; P = .008). For patients with eGFR greater than 45 mL/min/1.73.m², contrast media exposure was not associated with higher AKI risk (P > .05). Conclusion Contrast-enhanced CT was associated with higher risk of acute kidney injury and further hemodialysis among Taiwanese patients with an estimated glomerular filtration rate (eGFR) of less than 30 mL/min/1.73 m² but not those with an eGFR of more than 45 mL/min/1.73 m². © RSNA, 2021 Online supplemental material is available for this article.

Approach to Abdominal Imaging in 2022

Abdominal pain represents 5% to 7% of all emergency department presentations. Many patients require imaging for diagnosis, and choosing the appropriate imaging modality is a crucial decision point. Modern medicine offers a fantastic array of options including abdominal radiograph, computed tomography, MRI, and ultrasonography, but the plethora of alternatives can be paralyzing. This article introduces the commonly available modalities, discusses the advantages and disadvantages, and presents current recommendations for commonly diagnosed conditions.

Acute Kidney Injury After CT in Emergency Patients with Chronic Kidney Disease: A Propensity Score-matched Analysis

INTRODUCTION

Acute kidney injury (AKI) after intravenous contrast administration for computed tomography (CT) occurs infrequently, but certain patients may be susceptible. This study evaluated AKI incidence among emergency department (ED) patients with pre-existing chronic kidney disease (CKD) undergoing CT exams.

METHODS

This retrospective cohort study in an integrated healthcare system included ED patients previously diagnosed with CKD stages 3-5 (estimated glomerular filtration rate <60 milliliters per minute per 1.73 meters squared over at least three months), undergoing CT exams with or without intravenous contrast, from January 1, 2013-December 31, 2017. We excluded patients with CT prior to (30 days) or following (14 days) index CT and missing serum creatinine (sCr) measurements. We applied propensity score matching, and then multivariable regression adjustment for post-CT ED disposition and ED diagnosis, to calculate adjusted risk of AKI. Secondary patient-centered outcomes included 30-day mortality, end-stage renal disease (ESRD) diagnosis, and dialysis initiation.

RESULTS

Among 103,573 eligible ED patients undergoing CT, propensity score matching yielded 5,589 pairs. Adjusted risk ratio (ARR) for AKI was higher overall for contrast-enhanced CT (1.60; 95% confidence interval [CI], 1.43-1.79). However, secondary outcomes were infrequent: 19/5,589 non-contrast vs 40/5,589 contrast patients with new dialysis initiation at 30 days (adjusted risk 0.3% vs 0.7%; adjusted risk reduction 0.4%; 95% CI, 0.1%-0.7%).

CONCLUSION

In ED patients with chronic kidney disease undergoing CT, intravenous contrast was associated with higher overall adjusted risk of AKI, but patient-centered secondary outcomes were rare. The clinical significance of transient kidney injury after CT is unclear, although patients with advanced chronic kidney disease appear to have elevated risk.