Factors Predicting Contrast Induced Acute Kidney Injury in Patients Undergoing Contrast Enhanced Computed Tomography

Abstract

Introduction Contrast-induced acute kidney injury (CI-AKI) is an important adverse condition among patients undergoing contrast-enhanced computed tomography (CECT). Investigating the predictive factors of CI-AKI can help assess and monitor the risk of developing CI-AKI or mitigate its severity when it occurs. 

Objective The aims of this study were 1) to investigate the incidence of CI-AKI in patients underwent CECT, 2) to identify the relationship between systolic blood pressure (SBP) levels before CECT, diabetes mellitus (DM), estimated glomerular filtration rate (eGFR) before CECT, and consecutive CECT examinations within 24-72 hours and the risk of CI-AKI in patients undergoing CECT and 3) to investigate the predictive power of those variables to the risk of CI-AKI. 

Design Retrospective predictive correlational study guided by Roy’s Adaptation Model 

Methodology The data were collected from the medical records from the year 2016 to 2020 in a super-tertiary care hospital, Bangkok. Through purposive sampling, 260 in-patients met the inclusion criteria including aged 18 years old and above, and underwent CECT. The incidence of CI-AKI was analyzed using diagnostic criteria of Kidney Disease Improving Global Outcomes (KDIGO 2012). Logistic regression analysis was employed to examine the predictive power of CI-AKI risks, with the statistical significance level at .05. 

Results The sample included an almost equal distribution of both male and female participants. Among the participants, 60.8% were older adults, with an average age of 62.5 years (SD = 17.7). The incidence of contrast-induced acute kidney injury (CI-AKI) from contrast media was 38.8%. The predictive factors for CI-AKI included systolic blood pressure before contrast-enhanced computed tomography (CECT) (OR 21.953, 95% CI [2.635–182.87], p = .004), eGFR before CECT less than 60 mL/min/1.73 m2 (OR 4.887, 95% CI [2.603–9.176], p < .001), and repeat contrast media administration within 24-72 hours (OR 2.351, 95% CI [1.047–5.278], p = .038). Together, these factors could predict CI-AKI in patients undergoing CECT with a variability of 27.3% (Nagelkerke R2= .273, p < .05). 

Recommendation The study results indicate a higher incidence of kidney injuries resulting from contrast media exposure. The risk screening for patients is inadequate, and patients should be sufficiently protected against acute kidney injury (AKI) from contrast media due to various risk factors. Healthcare professionals should assess and closely monitor the occurrence of acute kidney injury in patients with low systolic blood pressure and low estimated glomerular filtration rate, and follow-up evaluations after repeated contrast media administration within 24-72 hours.