Can contrast media cause oliguria (decreased urine output)?

From the Guidelines

Yes, contrast can cause oliguria, which is a decreased urine output (typically less than 400-500 mL per day). This condition, known as contrast-induced acute kidney injury (CI-AKI) or contrast-induced nephropathy (CIN), occurs when iodinated contrast media used in imaging studies damages the kidneys. The risk is highest in patients with pre-existing kidney disease, diabetes, dehydration, heart failure, or advanced age. Contrast media can cause direct tubular toxicity, vasoconstriction of renal vessels, and increased oxidative stress, all of which can reduce kidney function and subsequently decrease urine output.

Prevention Strategies

Prevention strategies include:

• Adequate hydration before and after contrast administration (typically with intravenous normal saline) 1
• Minimizing contrast volume
• Using iso-osmolar or low-osmolar contrast agents rather than high-osmolar ones 1
• Avoidance of high-osmolar agents (1B) and use of the lowest possible radiocontrast dose (Not Graded) 1
• Withdrawal of potentially nephrotoxic agents before and after the procedure (1C) 1
• Measurement of GFR 48–96 hours after the procedure (1C) 1

High-Risk Patients

In high-risk patients, medications like metformin should be temporarily discontinued, and N-acetylcysteine may be considered as a protective agent, though evidence for its effectiveness is mixed 1. Monitoring kidney function through serum creatinine and urine output for 48-72 hours after contrast exposure is important for early detection of CI-AKI.

Key Recommendations

Key recommendations from KDIGO regarding management of chronic kidney disease (CKD) include:

• Avoidance of high-osmolar agents (1B)
• Use of the lowest possible radiocontrast dose (Not Graded)
• Withdrawal of potentially nephrotoxic agents before and after the procedure (1C)
• Adequate hydration with saline before, during, and after the procedure (1A)
• Measurement of GFR 48–96 hours after the procedure (1C) 1

From the Research

Contrast-Induced Oliguria

• Oliguria, a decrease in urine production, can be a symptom of contrast-induced nephropathy (CIN) 2, 3, 4.
• CIN is an adverse alteration in renal function induced by intravascular contrast media, and most cases involve transient asymptomatic episodes, yet a significant number involve oliguria and/or permanent renal damage 2.
• The incidence of CIN in the general hospitalized population is about 5%, and is associated with preexisting renal insufficiency and diabetes mellitus 2.
• Patients with preexisting renal insufficiency, diabetes mellitus, and congestive heart failure are at highest risk of developing CIN, which can lead to oliguria 3, 4.

Risk Factors for Contrast-Induced Oliguria

• Preexisting renal insufficiency is the most significant predisposing condition of contrast nephrotoxicity, and as many as two-thirds of patients with chronic renal failure may experience an acute deterioration in renal function following exposure to contrast media 2.
• Diabetic patients with preexisting renal insufficiency are at an even greater risk of developing CIN and oliguria, with about 75% of such patients experiencing renal complications 2.
• Other risk factors for CIN and oliguria include peripheral vascular disease, hypertension, old age, and large and repeated doses of contrast media 2, 4.

Prevention of Contrast-Induced Oliguria

• Adequate hydration does not appear to reduce the incidence of CIN in susceptible patients, but it may reduce the likelihood of oliguria and permanent damage 2.
• The use of non-ionic low-osmolar contrast media is preferred over high-osmolar contrast media in patients with renal impairment to reduce the risk of CIN and oliguria 4, 5.
• N-acetylcysteine (NAC) has been shown to have a protective effect on contrast media nephropathy and may reduce the incidence of oliguria 6.