Prevention of contrast-induced nephropathy in hospitalized patients with renal risk
The frequency of radiological techniques using iodinated contrast has grown enormously in recent years. These contrast agents can produce potential adverse effects, among which iodinated contrast-induced nephropathy stands out.
Contrast-induced nephropathy is a condition in which renal function impairment (an increase in serum creatinine of more than 25% or 44 μmol/l [0.5 mg/dl]) occurs within three days following intravascular administration of contrast media in the absence of another alternative etiology.
Contrast-induced nephropathy represents the third cause of acute renal failure (ARF) in hospitalized patients, highlighting the importance of preventive protocols.
Highly hyperosmolar compared to plasma osmolality. Higher risk of adverse reactions and side effects.
Lower osmolality than ionic ones, but with higher osmolality than plasma. Lower incidence of adverse reactions.
New isoosmolar contrast agents with plasma (290 mosmol/Kg). Lower risk of nephrotoxicity, especially in at-risk patients.
Before performing any test with iodinated contrast, the following mandatory questions should be asked to the patient:
Evaluate history of allergies, especially to contrast media, iodine, or shellfish.
Evaluate renal function. If nephrectomy, discuss with radiologist to adjust contrast dose (usually ml/kg).
If positive, discuss with radiologist for dose adjustment (ml/kg) always under medical order.
Check medical history for glomerular filtration rate (GFR) and creatinine levels.
For cases 2, 3 and 4 of the questionnaire, use of Iodixanol is proposed, a non-ionic, isoosmolar iodinated contrast agent (belongs to group 3 of mentioned contrast agents).
| Parameter | Limit Value | Recommended Action |
|---|---|---|
| Glomerular Filtration Rate (GFR) | < 45 ml/min/1.73 m² | Consider using Iodixanol |
| Creatinine (Women) | > 1.1 mg/dL | Consider using Iodixanol |
| Creatinine (Men) | > 1.4 mg/dL | Consider using Iodixanol |
The frequency and type of adverse reactions secondary to Iodixanol use are similar to other low-osmolarity iodinated contrast agents. However, it presents:
The best treatment for contrast-induced nephropathy is prevention. There are a series of preventive measures that can significantly reduce the risk.
Use of low contrast doses and avoid repeated studies close in time (48-72 hours).
Avoid volume depletion and use of NSAIDs, as both can increase renal vasoconstriction.
Use of saline solution to maintain adequate hydration before and after contrast.
Identify patients with increased probability of presenting abnormal serum creatinine levels.
• Diabetes mellitus
• Chronic renal failure
• Advanced age (>70 years)
• Dehydration
• Concurrent use of nephrotoxic drugs
• Baseline creatinine (before contrast)
• Creatinine at 48-72 hours post-contrast
• Continuous clinical assessment
• Record in medical history
• Informed consent
• Pre-contrast questionnaire
• Laboratory results
• Incidents and reactions
• Post-procedure follow-up