Acute Kidney Injury After Contrast Injection
Refers to a condition that occurs after a patient receives an injection of contrast media, which is a substance used to help visualize blood vessels or abnormalities inside the body more clearly during a computed tomography (CT scan)
Acute Kidney Injury
Refers to a condition where the blood creatinine level increases ≥ 0.3 milligrams per deciliter within 48 hours or increases ≥ 1.5 times from the baseline level and/or urine output decreases to less than 0.5 milliliters per kilogram of body weight for at least 6 hours
Mechanism of Acute Kidney Injury After Contrast Injection
(Contrast-Induced Acute Kidney Injury: CI-AKI) The exact cause is unknown but it is hypothesized to be due to the direct toxicity of the contrast media on renal tubular epithelial cells and the release of free radicals. Another hypothesis is related to the concentration of the contrast media causing the kidney cells to fail to adapt in time and indirectly causing cellular toxicity.
Occurrence of Acute Kidney Injury After Contrast Injection
It is commonly found in patients with risk factors according to the disease mechanism, such as pre-existing kidney disease which impairs the kidney cells’ ability to adapt. Especially if the glomerular filtration rate (GFR) is less than 30 milliliters per minute or if acute kidney injury is already present, these patients are at high risk. Other factors include old age, diabetes, heart failure, anemia, shock with low blood pressure, and the need for vasopressor drugs, etc.
The properties of the contrast media also affect the risk according to the disease mechanism. If the contrast media is of high concentration or used in large amounts, the risk increases. It has been found that every 100 milliliters increase in contrast media volume further raises the risk of acute kidney injury after contrast injection.
Acute kidney injury after contrast injection occurs within 48 hours, and creatinine levels typically return to normal within three to seven days. However, some high-risk patients may require temporary dialysis.
Generally, doctors prepare patients before contrast injection by managing underlying diseases, providing adequate hydration, and selecting kidney-safe contrast media. However, in emergency cases such as the need for immediate vascular catheterization and CT scan with contrast, doctors will explain the risk of acute kidney injury and do their best to prevent it.
From the Physician’s Perspective
Acute kidney injury after contrast media injection is not as frightening as many fear because it can be prevented to some extent. This article aims to help patients who are about to receive contrast media understand the basic principles, risk groups, and factors that can be prevented or modified before the examination.
If you or someone close to you is concerned about this condition, it is recommended to consult a specialist to assess the risk and plan appropriate prevention. At Phyathai 2 Hospital, we are pleased to provide care with attention and expertise at every step.
Dr. Methinee Sutthiwaikit
Nephrology Specialist
Dialysis Center, Phyathai 2 Hospital
