Kidney-Preservation Care Pathway: Bridging the Gap Between Contrast-Media Policy and Cath Lab Data
Kidney-preservation care pathway: closing the gap between contrast-media policy and procedure-room data
An effective kidney-preservation care pathway is not measured by its written recommendations—hydration, reduction of iodinated contrast, and audits—but by its ability to link decisions made in the procedure room with renal outcomes. This content is intended for Hospital Management and Clinical Governance teams seeking to transform the prevention of AKI (Acute Kidney Injury) from a “good-practice” initiative into a pathway that is manageable, auditable, and scalable. The key is to close the gap between contrast-media policy and operational data through a minimum set of structured information.
Why AKI prevention can fail even when appropriate policies are in place
Many European hospitals, including those in Italy, have well-established guidance on hydration, review of nephrotoxic medications, and the cautious use of iodinated contrast media. However, when AKI occurs after a procedure, the information needed to answer the most useful question for improving the system is often missing: what actually happened in the procedure room, under which parameters, and as a result of which operational decisions?
If an audit collects only retrospective or aggregated data—for example, the total volume of iodinated contrast used by a department—it cannot distinguish between different strategies, such as contrast-sparing, CO₂-first, and Zero Contrast, or link a complication to a modifiable step in the workflow. In practice, AKI remains a recorded clinical event rather than a controllable process indicator.
Hospital Management’s blind spot: without a standardized procedure-room log, there is no governance
Operator-dependent variability is a genuine factor in peripheral angiography and vascular interventions. It can affect acquisition timing, the number of injections, transitions from CO₂ to iodinated contrast, and repeated acquisitions due to image quality. When this information is distributed across narrative reports, nursing notes, and non-interoperable IT systems, Hospital Management does not have access to a standardized log suitable for cause-and-effect analysis.
This gap is particularly critical in contrast-sparing pathways, which intentionally reduce the use of iodinated contrast, and Zero Contrast pathways, which eliminate iodinated contrast during selected phases or procedures. Without traceability of the parameters used and the underlying clinical rationale, the project remains a pilot: potentially valuable, but not demonstrable through quantitative data and therefore difficult to establish as a permanent hospital policy.
A measurable kidney-preservation care pathway: the minimum data set to collect in the procedure room
A care pathway becomes measurable when it defines a small number of mandatory fields that are consistently collected and can be linked to outcomes. From a governance perspective, the most robust approach is to begin with a sustainable “minimum data set,” avoiding overly complex data-collection processes that are likely to be abandoned after only a few weeks.
- Pre-procedure risk: eGFR (estimated glomerular filtration rate), creatinine, diabetes, age, exposure to nephrotoxic medications, and the urgency or complexity of the procedure.
- Contrast strategy: CO₂-first, CO₂-only, or a combination of CO₂ and iodinated contrast; when conversion to iodinated contrast occurs, the reason should be recorded using a standardized code.
- Traceable procedure-room data: CO₂ injection parameters, including volume per injection, number of injections, and key settings, as well as the total residual volume of iodinated contrast in milliliters when used.
- Outcomes: AKI according to agreed criteria, such as KDIGO; need for dialysis; creatinine at 48–72 hours; LOS (length of stay); and 30-day readmissions.
- Procedural quality and safety: technical success and major complications; radiation exposure, where relevant.
With this minimum data set, Hospital Management can produce comparable analyses. For example, it can compare AKI rates in patients with similar eGFR values who underwent procedures using different contrast strategies. It can also assess whether reducing iodinated contrast is associated with shorter LOS and fewer readmissions, which are key indicators of sustainability and perceived quality of care.
Digital traceability of CO₂: standardizing the process to make outcomes attributable
CO₂ (carbon dioxide) is an alternative contrast agent typically used in procedures performed below the diaphragm, with the aim of reducing exposure to iodinated contrast in patients with chronic kidney disease (CKD), diabetes, or an allergy to iodinated contrast media. Historically, the main limitation has not been the clinical rationale, but the difficulty of standardizing performance and documentation when CO₂ administration is manual or poorly tracked.
Digital traceability of injection parameters enables more reliable audits and reduces dependence on individual operator experience. From this perspective, solutions such as the Angiodroid automatic CO₂ injector are not simply an alternative to iodinated contrast. They become an enabler of measurable care pathways by transforming operational decisions into consistent, comparable, and repeatable data across procedure rooms and operators.
How to avoid the “perpetual pilot”: KPIs, thresholds, and a continuous-improvement cycle
Moving from experimentation to governance requires a small, stable set of KPIs and a regular review process. One practical model is: data collection integrated into the workflow → monthly or quarterly review → operational decisions regarding protocols, training, and criteria for conversion to iodinated contrast → repeat measurement.
Examples of KPIs relevant to Hospital Management include AKI incidence by eGFR category, median residual iodinated contrast volume per procedure, the rate of conversion to iodinated contrast with coded reasons, LOS, and 30-day readmissions. With agreed thresholds—for example, residual iodinated contrast targets for specific procedures and risk profiles—exceptions become clinically justified cases rather than untracked variability.
When the data are robust, a local Health Technology Assessment (HTA) also becomes easier. The question is no longer simply whether a technology works, but in which patients, under which protocols, and with which outcomes. This is the step that makes a kidney-sparing technology scalable in Italy and across Europe, rather than leaving it as an open-ended project.
How-to: setting up a kidney-preservation care pathway based on procedure-room data
How to set up a measurable kidney-preservation care pathway in angiography
Step 1: Define the clinical scope, patient population, and definition of AKI
Select high-impact procedures and patient populations, such as below-the-diaphragm angiography and interventions, as well as patients with reduced eGFR, diabetes, or frailty. Adopt a single definition of AKI, such as the KDIGO criteria, and establish when creatinine and other outcomes will be measured—at 48–72 hours and 30 days—to ensure comparability.
Step 2: Establish the minimum data set and a data dictionary
Make a small number of fields mandatory: pre-procedure risk, including eGFR and creatinine; contrast strategy, including CO₂-first, CO₂-only, or a combination approach; recorded CO₂ parameters; residual iodinated contrast volume; AKI; LOS; and readmissions. Create an accompanying data dictionary specifying definitions, units of measurement, and standardized reasons for conversion to iodinated contrast.
Step 3: Integrate data collection into the procedure-room workflow and report
Collect data at the point of care through digital injection-parameter logs where available, structured fields in the procedure report, and completeness checks at the end of the procedure. Minimize manual steps: collect only a small amount of data, but collect it consistently.
Step 4: Define KPIs, operational thresholds, and review governance
Select three to five KPIs, such as AKI by eGFR category, residual iodinated contrast volume, conversion to iodinated contrast with a documented reason, LOS, and readmissions. Schedule a quarterly multidisciplinary review involving Interventional Radiology, Vascular Surgery, Nephrology, and Hospital Management to translate the data into protocol changes and targeted training.
Frequently Asked Questions
What is AKI, and how is it measured after a procedure involving contrast media?
AKI (Acute Kidney Injury) is an acute deterioration in kidney function, assessed primarily through an increase in serum creatinine and/or a reduction in urine output according to standard criteria such as KDIGO. After procedures involving contrast media, measurement at 48–72 hours helps identify early events. From a governance perspective, it is essential to use a single definition so that departments and time periods can be compared without ambiguity.
Why are hydration and reduction of iodinated contrast not enough to make AKI prevention measurable?
These are clinical interventions, but they do not automatically generate data that can be attributed to specific workflow decisions. Unless the contrast strategy, injection parameters, and residual iodinated contrast volume are recorded in a structured format, the audit remains descriptive and cannot support targeted corrective action. Prevention therefore remains dependent on individual behavior rather than on a controlled process.
What minimum data are needed to link procedure-room decisions with renal complications in a kidney-preservation care pathway?
The required data include pre-procedure risk, such as eGFR, creatinine, and major comorbidities; the contrast strategy, such as CO₂-first, CO₂-only, or a combination approach; recorded CO₂ parameters; total residual iodinated contrast volume; and outcomes, including AKI, dialysis, creatinine at 48–72 hours, LOS, and readmissions. This data set is sufficient for cause-and-effect analyses without creating an unmanageable data-collection process. The key is to keep definitions and units consistent over time.
In which settings is CO₂ most relevant as a kidney-sparing strategy?
CO₂ is typically used in peripheral angiography and vascular interventions below the diaphragm, particularly in patients with CKD, diabetes, or an allergy to iodinated contrast media. It is relevant when the objective is to reduce or eliminate iodinated contrast during selected stages of the care pathway while maintaining procedural safety and quality. Appropriateness depends on the patient’s anatomy, the clinical indication, and the center’s protocol, so CO₂ should be incorporated into a care pathway with dedicated criteria and training.
How can a CO₂ or Zero Contrast program be prevented from remaining an unscalable pilot project?
This can be achieved by defining KPIs, operational thresholds, and a periodic governance-review process based on standardized procedure-room data. Scalability requires reducing operator-dependent variability through repeatable protocols and traceable parameters, allowing results to be compared across procedure rooms and time periods. When processes and outcomes are linked, Hospital Management can make adoption and investment decisions based on local evidence rather than impressions.
When developing an auditable kidney-preservation care pathway, Angiodroid supports hospitals with traceable CO₂ workflows, contrast-sparing and Zero Contrast protocols, and team training—helping transform audits into measurable improvements in AKI, residual iodinated contrast volume, LOS, and readmissions.
