From the Guidelines
Injecting contrast into a dialysis line is not recommended due to the potential risks of damaging the dialysis access, infection, and complications from contrast media. The primary concerns include potential damage to the dialysis access, infection risk, and complications from contrast media, as highlighted in the context of contrast-enhanced imaging procedures 1. Hemodialysis access sites are critical for patients with end-stage renal disease, and preserving them is essential.
When considering contrast injection, it is crucial to evaluate the patient's risk of acute kidney injury (AKI), as suggested by the 2012 KDIGO clinical practice guideline commentary 1. This evaluation can help identify patients at high risk, for whom the benefits and risks of contrast administration need to be carefully weighed.
Key considerations for minimizing risks include:
- Using iso-osmolar or selected low-osmolal contrast in the lowest possible dose, especially in high-risk patients 1.
- Administering periprocedural intravenous volume using isotonic crystalloid to decrease the risk of contrast-induced AKI, as this is the only intervention consistently demonstrated to be effective 1.
- Ensuring strict aseptic technique and appropriate pressure limits if contrast injection is necessary.
- Thoroughly flushing the dialysis line before and after contrast administration to prevent clotting and reduce contrast retention.
- Coordinating with the nephrology team to manage subsequent dialysis sessions appropriately, considering the potential need to remove contrast through dialysis to prevent further kidney injury.
Given the potential complications and the importance of preserving dialysis access, the use of contrast through a dialysis line should be approached with caution and considered only when absolutely necessary, prioritizing the preservation of the dialysis access and the patient's overall renal function, in line with guidelines for managing patients at risk of contrast-induced AKI 1.
From the Research
Risks of Injecting Contrast into a Dialysis Line
- The risks of injecting contrast into a dialysis line include contrast-induced nephropathy (CIN) and systemic injury with exposure to gadolinium-based contrast agents (GBCA) 2.
- Patients with reduced renal function are at increased risk of nephrogenic systemic fibrosis (NSF) with GBCA exposure 2.
- The use of isotonic volume expansion and the lowest dose of low-osmolar or iso-osmolar contrast media possible can help decrease the risk of CIN 2, 3.
Considerations for Injecting Contrast into a Dialysis Line
- Strategies to avoid CIN, such as statins, remote ischemic preconditioning, and discontinuation of renin angiotensin aldosterone system (RAAS) blockade, are not currently recommended as routine prophylaxis for CIN due to limited evidence 2.
- Extracorporeal removal of contrast media, including hemodialysis and hemofiltration, may not be effective in reducing the risk of CIN 2, 3, 4.
- Immediate removal of contrast by dialysis is not recommended unless an individual's cardiopulmonary status is dependent on strict volume management 2, 5.
- Alternative imaging modalities should be considered in patients with reduced renal function or those at high risk for CIN 2, 6.
Patient Selection and Preparation
- Patients at high risk for CIN should be identified before procedures requiring contrast administration, including those with preexisting renal failure, diabetes mellitus, advanced age, and congestive heart failure 6.
- Metabolic syndrome, prediabetes, and hyperuricemia have been identified as new risk factors for CIN 6.
- The use of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers, renal transplantation, and low osmolar contrast medium in patients at high risk for CIN are considered conflicting risk factors 6.