Hinson JS, Ehmann MR, Fine DM et al.
Annals of Emergency Medicine 2017: 69 (5): 577–86.e4
Aim of Study
To determine whether the use of intravenous contrast for CT studies is associated with acute kidney injury and adverse outcomes
Design & Location
A single center retrospective cohort analysis in large urban academic ED in the USA.
17,934 patient visits to the ED who underwent CT with contrast, CT without contrast and those who did not have a CT at all were assessed over a 5-year period. Creatinine levels were assessed 8 hours prior to scan and re assessed 48-72 hours after.
The incidence of Acute Kidney Injury (AKI)
New Chronic Kidney Disease (CKD), dialysis and renal transplantation at 6 months.
Diachotomous variables displayed as percentages
Categorical data presented as relative frequencies
Continuous data presented as medians with interquartile ranges
A multivariable logistic regression model was also used to contrast media was associated with the risk of AKI after controlling for medical conditions and demographic variables
IV contrast was not associated with increased AKI (95% confidence interval 0.85-1.08), odds ratio 0.96.
Probability of developing an AKI
- Contrast Enhanced CT Patients: 6.8%
- Non-Contrast CT patients: 8.9 %
- Non-CT patients: 8.1%
Largest well controlled study of its kind revealed no obvious increase risk of AKI with the use of CT contrast. Clinician practice should be challenged
Stated Limitations from the Study
- Majority of patient in the study were admitted for medical reasons – higher risk of AKI
- Single centre study only – Clinician practice patterns / guidelines / population groups
- As a retrospective cohort – does not take into account patients who may have ended up at others hospitals
- Not all co-morbidities could be accounted for
- Limited to the Emergency Department only
Discussion from Journal Club Meeting (? Change of practice)
- Could possibly change clinical practice
- Are we delaying optimum treatment for those due to concern over the risk of developing an AKI?
- Clinicians to question the risk vs benefit of CT with contrast / potential missed diagnosis / incorrect treatment
- It was noted that the clinician practice may have affected outcomes. Those with lower EGFRs in the ED did not have contrast and those that did have nephroprotective behaviour such as IV fluids before and after.
- It was noted younger patients seemed to have the CTs with contrast
- RCT would be the true study method to determine accurate results – however ethical issues would most likely implicate this from happening.
Summary by Dr D. Vaca. Journal Club 14 December 2017.