Risk factors to predict post-contrast acute kidney injury after contrast-enhanced computed tomography in the emergency department

Objective:
This study aimed to investigate the risk factors of post-contrast acute kidney injury (PAKI) and the usefulness of the Mehran score for predicting PAKI in patients who underwent contrast-enhanced abdominopelvic computed tomography (CE-APCT) in the emergency department (ED).
Method:
This was a retrospective observational study. Patients who underwent CE-APCT and had a follow-up creatinine test within 72 hours in the period January to June, 2017, were enrolled for the study. PAKI is defined as a 25% or higher increase in the level of serum creatinine (sCr) within 72 hours after receiving contrast, or an increase in the level of sCr by 0.5 mg/dL. The odds ratio (OR) of risk factors and incidence of PAKI after CE-APCT were analyzed according to the Mehran risk group, and compared to expected incidence. Univariate and multivariate logistic regression analyses were performed for each risk factor.
Results:
A total of 1,718 patients were enrolled in the study. Of these, 203 patients (11.8%) developed PAKI, and 2 patients (0.1%) required dialysis. Hypotension (systolic blood pressure <80 mmHg) was determined to be statistically significant (P=0.029; OR, 3.181) among the considered risk factors of PAKI. In the group having abnormal estimatedglomerular filtration rate (<90 mL/min/1.73 m²), the age and rate of the underlying disease (congestive heart failure, hypertension) was found to be higher in the PAKI group. The receiver operating curve of Mehran score (area under the curve: 0.521 in model A, 0.520 in model B) was statistically not significant in the univariate analysis. A higher Mehran score was associated with a higher proportion of patients who underwent prophylactic treatment.
Conclusion:
There are no definite useful risk factors, including the Mehran score, for predicting PAKI in patients who underwent contrast-enhanced computed tomography in the ED.

Key words: Contrast media; Acute kidney injury; Computed tomography; Emergency department